1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register.
36 Call `put_var_into_stack' when you learn, belatedly, that a variable
37 previously given a pseudo-register must in fact go in the stack.
38 This function changes the DECL_RTL to be a stack slot instead of a reg
39 then scans all the RTL instructions so far generated to correct them. */
43 #include "coretypes.h"
54 #include "hard-reg-set.h"
55 #include "insn-config.h"
58 #include "basic-block.h"
63 #include "integrate.h"
64 #include "langhooks.h"
67 #ifndef TRAMPOLINE_ALIGNMENT
68 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
71 #ifndef LOCAL_ALIGNMENT
72 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
75 #ifndef STACK_ALIGNMENT_NEEDED
76 #define STACK_ALIGNMENT_NEEDED 1
79 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
81 /* Some systems use __main in a way incompatible with its use in gcc, in these
82 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
83 give the same symbol without quotes for an alternative entry point. You
84 must define both, or neither. */
86 #define NAME__MAIN "__main"
89 /* Round a value to the lowest integer less than it that is a multiple of
90 the required alignment. Avoid using division in case the value is
91 negative. Assume the alignment is a power of two. */
92 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
94 /* Similar, but round to the next highest integer that meets the
96 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
98 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
99 during rtl generation. If they are different register numbers, this is
100 always true. It may also be true if
101 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
102 generation. See fix_lexical_addr for details. */
104 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
105 #define NEED_SEPARATE_AP
108 /* Nonzero if function being compiled doesn't contain any calls
109 (ignoring the prologue and epilogue). This is set prior to
110 local register allocation and is valid for the remaining
112 int current_function_is_leaf;
114 /* Nonzero if function being compiled doesn't contain any instructions
115 that can throw an exception. This is set prior to final. */
117 int current_function_nothrow;
119 /* Nonzero if function being compiled doesn't modify the stack pointer
120 (ignoring the prologue and epilogue). This is only valid after
121 life_analysis has run. */
122 int current_function_sp_is_unchanging;
124 /* Nonzero if the function being compiled is a leaf function which only
125 uses leaf registers. This is valid after reload (specifically after
126 sched2) and is useful only if the port defines LEAF_REGISTERS. */
127 int current_function_uses_only_leaf_regs;
129 /* Nonzero once virtual register instantiation has been done.
130 assign_stack_local uses frame_pointer_rtx when this is nonzero.
131 calls.c:emit_library_call_value_1 uses it to set up
132 post-instantiation libcalls. */
133 int virtuals_instantiated;
135 /* Nonzero if at least one trampoline has been created. */
136 int trampolines_created;
138 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
139 static GTY(()) int funcdef_no;
141 /* These variables hold pointers to functions to create and destroy
142 target specific, per-function data structures. */
143 struct machine_function * (*init_machine_status) (void);
145 /* The FUNCTION_DECL for an inline function currently being expanded. */
146 tree inline_function_decl;
148 /* The currently compiled function. */
149 struct function *cfun = 0;
151 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
152 static GTY(()) varray_type prologue;
153 static GTY(()) varray_type epilogue;
155 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
157 static GTY(()) varray_type sibcall_epilogue;
159 /* In order to evaluate some expressions, such as function calls returning
160 structures in memory, we need to temporarily allocate stack locations.
161 We record each allocated temporary in the following structure.
163 Associated with each temporary slot is a nesting level. When we pop up
164 one level, all temporaries associated with the previous level are freed.
165 Normally, all temporaries are freed after the execution of the statement
166 in which they were created. However, if we are inside a ({...}) grouping,
167 the result may be in a temporary and hence must be preserved. If the
168 result could be in a temporary, we preserve it if we can determine which
169 one it is in. If we cannot determine which temporary may contain the
170 result, all temporaries are preserved. A temporary is preserved by
171 pretending it was allocated at the previous nesting level.
173 Automatic variables are also assigned temporary slots, at the nesting
174 level where they are defined. They are marked a "kept" so that
175 free_temp_slots will not free them. */
177 struct temp_slot GTY(())
179 /* Points to next temporary slot. */
180 struct temp_slot *next;
181 /* The rtx to used to reference the slot. */
183 /* The rtx used to represent the address if not the address of the
184 slot above. May be an EXPR_LIST if multiple addresses exist. */
186 /* The alignment (in bits) of the slot. */
188 /* The size, in units, of the slot. */
190 /* The type of the object in the slot, or zero if it doesn't correspond
191 to a type. We use this to determine whether a slot can be reused.
192 It can be reused if objects of the type of the new slot will always
193 conflict with objects of the type of the old slot. */
195 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
197 /* Nonzero if this temporary is currently in use. */
199 /* Nonzero if this temporary has its address taken. */
201 /* Nesting level at which this slot is being used. */
203 /* Nonzero if this should survive a call to free_temp_slots. */
205 /* The offset of the slot from the frame_pointer, including extra space
206 for alignment. This info is for combine_temp_slots. */
207 HOST_WIDE_INT base_offset;
208 /* The size of the slot, including extra space for alignment. This
209 info is for combine_temp_slots. */
210 HOST_WIDE_INT full_size;
213 /* This structure is used to record MEMs or pseudos used to replace VAR, any
214 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
215 maintain this list in case two operands of an insn were required to match;
216 in that case we must ensure we use the same replacement. */
218 struct fixup_replacement GTY(())
222 struct fixup_replacement *next;
225 struct insns_for_mem_entry
229 /* These are the INSNs which reference the MEM. */
233 /* Forward declarations. */
235 static rtx assign_stack_local_1 (enum machine_mode, HOST_WIDE_INT, int,
237 static struct temp_slot *find_temp_slot_from_address (rtx);
238 static void put_reg_into_stack (struct function *, rtx, tree, enum machine_mode,
239 enum machine_mode, int, unsigned int, int, htab_t);
240 static void schedule_fixup_var_refs (struct function *, rtx, tree, enum machine_mode,
242 static void fixup_var_refs (rtx, enum machine_mode, int, rtx, htab_t);
243 static struct fixup_replacement
244 *find_fixup_replacement (struct fixup_replacement **, rtx);
245 static void fixup_var_refs_insns (rtx, rtx, enum machine_mode, int, int, rtx);
246 static void fixup_var_refs_insns_with_hash (htab_t, rtx, enum machine_mode, int, rtx);
247 static void fixup_var_refs_insn (rtx, rtx, enum machine_mode, int, int, rtx);
248 static void fixup_var_refs_1 (rtx, enum machine_mode, rtx *, rtx,
249 struct fixup_replacement **, rtx);
250 static rtx fixup_memory_subreg (rtx, rtx, enum machine_mode, int);
251 static rtx walk_fixup_memory_subreg (rtx, rtx, enum machine_mode, int);
252 static rtx fixup_stack_1 (rtx, rtx);
253 static void optimize_bit_field (rtx, rtx, rtx *);
254 static void instantiate_decls (tree, int);
255 static void instantiate_decls_1 (tree, int);
256 static void instantiate_decl (rtx, HOST_WIDE_INT, int);
257 static rtx instantiate_new_reg (rtx, HOST_WIDE_INT *);
258 static int instantiate_virtual_regs_1 (rtx *, rtx, int);
259 static void delete_handlers (void);
260 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
261 static void pad_below (struct args_size *, enum machine_mode, tree);
262 static rtx round_trampoline_addr (rtx);
263 static rtx adjust_trampoline_addr (rtx);
264 static tree *identify_blocks_1 (rtx, tree *, tree *, tree *);
265 static void reorder_blocks_0 (tree);
266 static void reorder_blocks_1 (rtx, tree, varray_type *);
267 static void reorder_fix_fragments (tree);
268 static tree blocks_nreverse (tree);
269 static int all_blocks (tree, tree *);
270 static tree *get_block_vector (tree, int *);
271 extern tree debug_find_var_in_block_tree (tree, tree);
272 /* We always define `record_insns' even if its not used so that we
273 can always export `prologue_epilogue_contains'. */
274 static void record_insns (rtx, varray_type *) ATTRIBUTE_UNUSED;
275 static int contains (rtx, varray_type);
277 static void emit_return_into_block (basic_block, rtx);
279 static void put_addressof_into_stack (rtx, htab_t);
280 static bool purge_addressof_1 (rtx *, rtx, int, int, int, htab_t);
281 static void purge_single_hard_subreg_set (rtx);
282 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
283 static rtx keep_stack_depressed (rtx);
285 static int is_addressof (rtx *, void *);
286 static hashval_t insns_for_mem_hash (const void *);
287 static int insns_for_mem_comp (const void *, const void *);
288 static int insns_for_mem_walk (rtx *, void *);
289 static void compute_insns_for_mem (rtx, rtx, htab_t);
290 static void prepare_function_start (tree);
291 static void do_clobber_return_reg (rtx, void *);
292 static void do_use_return_reg (rtx, void *);
293 static void instantiate_virtual_regs_lossage (rtx);
294 static tree split_complex_args (tree);
295 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
297 /* Pointer to chain of `struct function' for containing functions. */
298 struct function *outer_function_chain;
300 /* List of insns that were postponed by purge_addressof_1. */
301 static rtx postponed_insns;
303 /* Given a function decl for a containing function,
304 return the `struct function' for it. */
307 find_function_data (tree decl)
311 for (p = outer_function_chain; p; p = p->outer)
318 /* Save the current context for compilation of a nested function.
319 This is called from language-specific code. The caller should use
320 the enter_nested langhook to save any language-specific state,
321 since this function knows only about language-independent
325 push_function_context_to (tree context)
331 if (context == current_function_decl)
332 cfun->contains_functions = 1;
335 struct function *containing = find_function_data (context);
336 containing->contains_functions = 1;
341 init_dummy_function_start ();
344 p->outer = outer_function_chain;
345 outer_function_chain = p;
346 p->fixup_var_refs_queue = 0;
348 (*lang_hooks.function.enter_nested) (p);
354 push_function_context (void)
356 push_function_context_to (current_function_decl);
359 /* Restore the last saved context, at the end of a nested function.
360 This function is called from language-specific code. */
363 pop_function_context_from (tree context ATTRIBUTE_UNUSED)
365 struct function *p = outer_function_chain;
366 struct var_refs_queue *queue;
369 outer_function_chain = p->outer;
371 current_function_decl = p->decl;
374 restore_emit_status (p);
376 (*lang_hooks.function.leave_nested) (p);
378 /* Finish doing put_var_into_stack for any of our variables which became
379 addressable during the nested function. If only one entry has to be
380 fixed up, just do that one. Otherwise, first make a list of MEMs that
381 are not to be unshared. */
382 if (p->fixup_var_refs_queue == 0)
384 else if (p->fixup_var_refs_queue->next == 0)
385 fixup_var_refs (p->fixup_var_refs_queue->modified,
386 p->fixup_var_refs_queue->promoted_mode,
387 p->fixup_var_refs_queue->unsignedp,
388 p->fixup_var_refs_queue->modified, 0);
393 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
394 list = gen_rtx_EXPR_LIST (VOIDmode, queue->modified, list);
396 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
397 fixup_var_refs (queue->modified, queue->promoted_mode,
398 queue->unsignedp, list, 0);
402 p->fixup_var_refs_queue = 0;
404 /* Reset variables that have known state during rtx generation. */
405 rtx_equal_function_value_matters = 1;
406 virtuals_instantiated = 0;
407 generating_concat_p = 1;
411 pop_function_context (void)
413 pop_function_context_from (current_function_decl);
416 /* Clear out all parts of the state in F that can safely be discarded
417 after the function has been parsed, but not compiled, to let
418 garbage collection reclaim the memory. */
421 free_after_parsing (struct function *f)
423 /* f->expr->forced_labels is used by code generation. */
424 /* f->emit->regno_reg_rtx is used by code generation. */
425 /* f->varasm is used by code generation. */
426 /* f->eh->eh_return_stub_label is used by code generation. */
428 (*lang_hooks.function.final) (f);
432 /* Clear out all parts of the state in F that can safely be discarded
433 after the function has been compiled, to let garbage collection
434 reclaim the memory. */
437 free_after_compilation (struct function *f)
445 f->x_temp_slots = NULL;
446 f->arg_offset_rtx = NULL;
447 f->return_rtx = NULL;
448 f->internal_arg_pointer = NULL;
449 f->x_nonlocal_labels = NULL;
450 f->x_nonlocal_goto_handler_slots = NULL;
451 f->x_nonlocal_goto_handler_labels = NULL;
452 f->x_nonlocal_goto_stack_level = NULL;
453 f->x_cleanup_label = NULL;
454 f->x_return_label = NULL;
455 f->x_naked_return_label = NULL;
456 f->computed_goto_common_label = NULL;
457 f->computed_goto_common_reg = NULL;
458 f->x_save_expr_regs = NULL;
459 f->x_stack_slot_list = NULL;
460 f->x_rtl_expr_chain = NULL;
461 f->x_tail_recursion_label = NULL;
462 f->x_tail_recursion_reentry = NULL;
463 f->x_arg_pointer_save_area = NULL;
464 f->x_clobber_return_insn = NULL;
465 f->x_context_display = NULL;
466 f->x_trampoline_list = NULL;
467 f->x_parm_birth_insn = NULL;
468 f->x_last_parm_insn = NULL;
469 f->x_parm_reg_stack_loc = NULL;
470 f->fixup_var_refs_queue = NULL;
471 f->original_arg_vector = NULL;
472 f->original_decl_initial = NULL;
473 f->inl_last_parm_insn = NULL;
474 f->epilogue_delay_list = NULL;
477 /* Allocate fixed slots in the stack frame of the current function. */
479 /* Return size needed for stack frame based on slots so far allocated in
481 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
482 the caller may have to do that. */
485 get_func_frame_size (struct function *f)
487 #ifdef FRAME_GROWS_DOWNWARD
488 return -f->x_frame_offset;
490 return f->x_frame_offset;
494 /* Return size needed for stack frame based on slots so far allocated.
495 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
496 the caller may have to do that. */
498 get_frame_size (void)
500 return get_func_frame_size (cfun);
503 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
504 with machine mode MODE.
506 ALIGN controls the amount of alignment for the address of the slot:
507 0 means according to MODE,
508 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
509 positive specifies alignment boundary in bits.
511 We do not round to stack_boundary here.
513 FUNCTION specifies the function to allocate in. */
516 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size, int align,
517 struct function *function)
520 int bigend_correction = 0;
522 int frame_off, frame_alignment, frame_phase;
529 alignment = BIGGEST_ALIGNMENT;
531 alignment = GET_MODE_ALIGNMENT (mode);
533 /* Allow the target to (possibly) increase the alignment of this
535 type = (*lang_hooks.types.type_for_mode) (mode, 0);
537 alignment = LOCAL_ALIGNMENT (type, alignment);
539 alignment /= BITS_PER_UNIT;
541 else if (align == -1)
543 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
544 size = CEIL_ROUND (size, alignment);
547 alignment = align / BITS_PER_UNIT;
549 #ifdef FRAME_GROWS_DOWNWARD
550 function->x_frame_offset -= size;
553 /* Ignore alignment we can't do with expected alignment of the boundary. */
554 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
555 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
557 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
558 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
560 /* Calculate how many bytes the start of local variables is off from
562 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
563 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
564 frame_phase = frame_off ? frame_alignment - frame_off : 0;
566 /* Round the frame offset to the specified alignment. The default is
567 to always honor requests to align the stack but a port may choose to
568 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
569 if (STACK_ALIGNMENT_NEEDED
573 /* We must be careful here, since FRAME_OFFSET might be negative and
574 division with a negative dividend isn't as well defined as we might
575 like. So we instead assume that ALIGNMENT is a power of two and
576 use logical operations which are unambiguous. */
577 #ifdef FRAME_GROWS_DOWNWARD
578 function->x_frame_offset
579 = (FLOOR_ROUND (function->x_frame_offset - frame_phase, alignment)
582 function->x_frame_offset
583 = (CEIL_ROUND (function->x_frame_offset - frame_phase, alignment)
588 /* On a big-endian machine, if we are allocating more space than we will use,
589 use the least significant bytes of those that are allocated. */
590 if (BYTES_BIG_ENDIAN && mode != BLKmode)
591 bigend_correction = size - GET_MODE_SIZE (mode);
593 /* If we have already instantiated virtual registers, return the actual
594 address relative to the frame pointer. */
595 if (function == cfun && virtuals_instantiated)
596 addr = plus_constant (frame_pointer_rtx,
598 (frame_offset + bigend_correction
599 + STARTING_FRAME_OFFSET, Pmode));
601 addr = plus_constant (virtual_stack_vars_rtx,
603 (function->x_frame_offset + bigend_correction,
606 #ifndef FRAME_GROWS_DOWNWARD
607 function->x_frame_offset += size;
610 x = gen_rtx_MEM (mode, addr);
612 function->x_stack_slot_list
613 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
618 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
622 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
624 return assign_stack_local_1 (mode, size, align, cfun);
627 /* Allocate a temporary stack slot and record it for possible later
630 MODE is the machine mode to be given to the returned rtx.
632 SIZE is the size in units of the space required. We do no rounding here
633 since assign_stack_local will do any required rounding.
635 KEEP is 1 if this slot is to be retained after a call to
636 free_temp_slots. Automatic variables for a block are allocated
637 with this flag. KEEP is 2 if we allocate a longer term temporary,
638 whose lifetime is controlled by CLEANUP_POINT_EXPRs. KEEP is 3
639 if we are to allocate something at an inner level to be treated as
640 a variable in the block (e.g., a SAVE_EXPR).
642 TYPE is the type that will be used for the stack slot. */
645 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size, int keep,
649 struct temp_slot *p, *best_p = 0;
652 /* If SIZE is -1 it means that somebody tried to allocate a temporary
653 of a variable size. */
658 align = BIGGEST_ALIGNMENT;
660 align = GET_MODE_ALIGNMENT (mode);
663 type = (*lang_hooks.types.type_for_mode) (mode, 0);
666 align = LOCAL_ALIGNMENT (type, align);
668 /* Try to find an available, already-allocated temporary of the proper
669 mode which meets the size and alignment requirements. Choose the
670 smallest one with the closest alignment. */
671 for (p = temp_slots; p; p = p->next)
672 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
674 && objects_must_conflict_p (p->type, type)
675 && (best_p == 0 || best_p->size > p->size
676 || (best_p->size == p->size && best_p->align > p->align)))
678 if (p->align == align && p->size == size)
686 /* Make our best, if any, the one to use. */
689 /* If there are enough aligned bytes left over, make them into a new
690 temp_slot so that the extra bytes don't get wasted. Do this only
691 for BLKmode slots, so that we can be sure of the alignment. */
692 if (GET_MODE (best_p->slot) == BLKmode)
694 int alignment = best_p->align / BITS_PER_UNIT;
695 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
697 if (best_p->size - rounded_size >= alignment)
699 p = ggc_alloc (sizeof (struct temp_slot));
700 p->in_use = p->addr_taken = 0;
701 p->size = best_p->size - rounded_size;
702 p->base_offset = best_p->base_offset + rounded_size;
703 p->full_size = best_p->full_size - rounded_size;
704 p->slot = gen_rtx_MEM (BLKmode,
705 plus_constant (XEXP (best_p->slot, 0),
707 p->align = best_p->align;
710 p->type = best_p->type;
711 p->next = temp_slots;
714 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
717 best_p->size = rounded_size;
718 best_p->full_size = rounded_size;
725 /* If we still didn't find one, make a new temporary. */
728 HOST_WIDE_INT frame_offset_old = frame_offset;
730 p = ggc_alloc (sizeof (struct temp_slot));
732 /* We are passing an explicit alignment request to assign_stack_local.
733 One side effect of that is assign_stack_local will not round SIZE
734 to ensure the frame offset remains suitably aligned.
736 So for requests which depended on the rounding of SIZE, we go ahead
737 and round it now. We also make sure ALIGNMENT is at least
738 BIGGEST_ALIGNMENT. */
739 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
741 p->slot = assign_stack_local (mode,
743 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
749 /* The following slot size computation is necessary because we don't
750 know the actual size of the temporary slot until assign_stack_local
751 has performed all the frame alignment and size rounding for the
752 requested temporary. Note that extra space added for alignment
753 can be either above or below this stack slot depending on which
754 way the frame grows. We include the extra space if and only if it
755 is above this slot. */
756 #ifdef FRAME_GROWS_DOWNWARD
757 p->size = frame_offset_old - frame_offset;
762 /* Now define the fields used by combine_temp_slots. */
763 #ifdef FRAME_GROWS_DOWNWARD
764 p->base_offset = frame_offset;
765 p->full_size = frame_offset_old - frame_offset;
767 p->base_offset = frame_offset_old;
768 p->full_size = frame_offset - frame_offset_old;
771 p->next = temp_slots;
777 p->rtl_expr = seq_rtl_expr;
782 p->level = target_temp_slot_level;
787 p->level = var_temp_slot_level;
792 p->level = temp_slot_level;
797 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
798 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
799 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
801 /* If we know the alias set for the memory that will be used, use
802 it. If there's no TYPE, then we don't know anything about the
803 alias set for the memory. */
804 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
805 set_mem_align (slot, align);
807 /* If a type is specified, set the relevant flags. */
810 RTX_UNCHANGING_P (slot) = (lang_hooks.honor_readonly
811 && TYPE_READONLY (type));
812 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
813 MEM_SET_IN_STRUCT_P (slot, AGGREGATE_TYPE_P (type));
819 /* Allocate a temporary stack slot and record it for possible later
820 reuse. First three arguments are same as in preceding function. */
823 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
825 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
828 /* Assign a temporary.
829 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
830 and so that should be used in error messages. In either case, we
831 allocate of the given type.
832 KEEP is as for assign_stack_temp.
833 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
834 it is 0 if a register is OK.
835 DONT_PROMOTE is 1 if we should not promote values in register
839 assign_temp (tree type_or_decl, int keep, int memory_required,
840 int dont_promote ATTRIBUTE_UNUSED)
843 enum machine_mode mode;
844 #ifndef PROMOTE_FOR_CALL_ONLY
848 if (DECL_P (type_or_decl))
849 decl = type_or_decl, type = TREE_TYPE (decl);
851 decl = NULL, type = type_or_decl;
853 mode = TYPE_MODE (type);
854 #ifndef PROMOTE_FOR_CALL_ONLY
855 unsignedp = TREE_UNSIGNED (type);
858 if (mode == BLKmode || memory_required)
860 HOST_WIDE_INT size = int_size_in_bytes (type);
863 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
864 problems with allocating the stack space. */
868 /* Unfortunately, we don't yet know how to allocate variable-sized
869 temporaries. However, sometimes we have a fixed upper limit on
870 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
871 instead. This is the case for Chill variable-sized strings. */
872 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
873 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
874 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
875 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
877 /* The size of the temporary may be too large to fit into an integer. */
878 /* ??? Not sure this should happen except for user silliness, so limit
879 this to things that aren't compiler-generated temporaries. The
880 rest of the time we'll abort in assign_stack_temp_for_type. */
881 if (decl && size == -1
882 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
884 error ("%Jsize of variable '%D' is too large", decl, decl);
888 tmp = assign_stack_temp_for_type (mode, size, keep, type);
892 #ifndef PROMOTE_FOR_CALL_ONLY
894 mode = promote_mode (type, mode, &unsignedp, 0);
897 return gen_reg_rtx (mode);
900 /* Combine temporary stack slots which are adjacent on the stack.
902 This allows for better use of already allocated stack space. This is only
903 done for BLKmode slots because we can be sure that we won't have alignment
904 problems in this case. */
907 combine_temp_slots (void)
909 struct temp_slot *p, *q;
910 struct temp_slot *prev_p, *prev_q;
913 /* We can't combine slots, because the information about which slot
914 is in which alias set will be lost. */
915 if (flag_strict_aliasing)
918 /* If there are a lot of temp slots, don't do anything unless
919 high levels of optimization. */
920 if (! flag_expensive_optimizations)
921 for (p = temp_slots, num_slots = 0; p; p = p->next, num_slots++)
922 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
925 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
929 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
930 for (q = p->next, prev_q = p; q; q = prev_q->next)
933 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
935 if (p->base_offset + p->full_size == q->base_offset)
937 /* Q comes after P; combine Q into P. */
939 p->full_size += q->full_size;
942 else if (q->base_offset + q->full_size == p->base_offset)
944 /* P comes after Q; combine P into Q. */
946 q->full_size += p->full_size;
951 /* Either delete Q or advance past it. */
953 prev_q->next = q->next;
957 /* Either delete P or advance past it. */
961 prev_p->next = p->next;
963 temp_slots = p->next;
970 /* Find the temp slot corresponding to the object at address X. */
972 static struct temp_slot *
973 find_temp_slot_from_address (rtx x)
978 for (p = temp_slots; p; p = p->next)
983 else if (XEXP (p->slot, 0) == x
985 || (GET_CODE (x) == PLUS
986 && XEXP (x, 0) == virtual_stack_vars_rtx
987 && GET_CODE (XEXP (x, 1)) == CONST_INT
988 && INTVAL (XEXP (x, 1)) >= p->base_offset
989 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
992 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
993 for (next = p->address; next; next = XEXP (next, 1))
994 if (XEXP (next, 0) == x)
998 /* If we have a sum involving a register, see if it points to a temp
1000 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == REG
1001 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
1003 else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == REG
1004 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
1010 /* Indicate that NEW is an alternate way of referring to the temp slot
1011 that previously was known by OLD. */
1014 update_temp_slot_address (rtx old, rtx new)
1016 struct temp_slot *p;
1018 if (rtx_equal_p (old, new))
1021 p = find_temp_slot_from_address (old);
1023 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
1024 is a register, see if one operand of the PLUS is a temporary
1025 location. If so, NEW points into it. Otherwise, if both OLD and
1026 NEW are a PLUS and if there is a register in common between them.
1027 If so, try a recursive call on those values. */
1030 if (GET_CODE (old) != PLUS)
1033 if (GET_CODE (new) == REG)
1035 update_temp_slot_address (XEXP (old, 0), new);
1036 update_temp_slot_address (XEXP (old, 1), new);
1039 else if (GET_CODE (new) != PLUS)
1042 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
1043 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
1044 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
1045 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
1046 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
1047 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
1048 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1049 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1054 /* Otherwise add an alias for the temp's address. */
1055 else if (p->address == 0)
1059 if (GET_CODE (p->address) != EXPR_LIST)
1060 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1062 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1066 /* If X could be a reference to a temporary slot, mark the fact that its
1067 address was taken. */
1070 mark_temp_addr_taken (rtx x)
1072 struct temp_slot *p;
1077 /* If X is not in memory or is at a constant address, it cannot be in
1078 a temporary slot. */
1079 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1082 p = find_temp_slot_from_address (XEXP (x, 0));
1087 /* If X could be a reference to a temporary slot, mark that slot as
1088 belonging to the to one level higher than the current level. If X
1089 matched one of our slots, just mark that one. Otherwise, we can't
1090 easily predict which it is, so upgrade all of them. Kept slots
1091 need not be touched.
1093 This is called when an ({...}) construct occurs and a statement
1094 returns a value in memory. */
1097 preserve_temp_slots (rtx x)
1099 struct temp_slot *p = 0;
1101 /* If there is no result, we still might have some objects whose address
1102 were taken, so we need to make sure they stay around. */
1105 for (p = temp_slots; p; p = p->next)
1106 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1112 /* If X is a register that is being used as a pointer, see if we have
1113 a temporary slot we know it points to. To be consistent with
1114 the code below, we really should preserve all non-kept slots
1115 if we can't find a match, but that seems to be much too costly. */
1116 if (GET_CODE (x) == REG && REG_POINTER (x))
1117 p = find_temp_slot_from_address (x);
1119 /* If X is not in memory or is at a constant address, it cannot be in
1120 a temporary slot, but it can contain something whose address was
1122 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1124 for (p = temp_slots; p; p = p->next)
1125 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1131 /* First see if we can find a match. */
1133 p = find_temp_slot_from_address (XEXP (x, 0));
1137 /* Move everything at our level whose address was taken to our new
1138 level in case we used its address. */
1139 struct temp_slot *q;
1141 if (p->level == temp_slot_level)
1143 for (q = temp_slots; q; q = q->next)
1144 if (q != p && q->addr_taken && q->level == p->level)
1153 /* Otherwise, preserve all non-kept slots at this level. */
1154 for (p = temp_slots; p; p = p->next)
1155 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1159 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1160 with that RTL_EXPR, promote it into a temporary slot at the present
1161 level so it will not be freed when we free slots made in the
1165 preserve_rtl_expr_result (rtx x)
1167 struct temp_slot *p;
1169 /* If X is not in memory or is at a constant address, it cannot be in
1170 a temporary slot. */
1171 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1174 /* If we can find a match, move it to our level unless it is already at
1176 p = find_temp_slot_from_address (XEXP (x, 0));
1179 p->level = MIN (p->level, temp_slot_level);
1186 /* Free all temporaries used so far. This is normally called at the end
1187 of generating code for a statement. Don't free any temporaries
1188 currently in use for an RTL_EXPR that hasn't yet been emitted.
1189 We could eventually do better than this since it can be reused while
1190 generating the same RTL_EXPR, but this is complex and probably not
1194 free_temp_slots (void)
1196 struct temp_slot *p;
1198 for (p = temp_slots; p; p = p->next)
1199 if (p->in_use && p->level == temp_slot_level && ! p->keep
1200 && p->rtl_expr == 0)
1203 combine_temp_slots ();
1206 /* Free all temporary slots used in T, an RTL_EXPR node. */
1209 free_temps_for_rtl_expr (tree t)
1211 struct temp_slot *p;
1213 for (p = temp_slots; p; p = p->next)
1214 if (p->rtl_expr == t)
1216 /* If this slot is below the current TEMP_SLOT_LEVEL, then it
1217 needs to be preserved. This can happen if a temporary in
1218 the RTL_EXPR was addressed; preserve_temp_slots will move
1219 the temporary into a higher level. */
1220 if (temp_slot_level <= p->level)
1223 p->rtl_expr = NULL_TREE;
1226 combine_temp_slots ();
1229 /* Mark all temporaries ever allocated in this function as not suitable
1230 for reuse until the current level is exited. */
1233 mark_all_temps_used (void)
1235 struct temp_slot *p;
1237 for (p = temp_slots; p; p = p->next)
1239 p->in_use = p->keep = 1;
1240 p->level = MIN (p->level, temp_slot_level);
1244 /* Push deeper into the nesting level for stack temporaries. */
1247 push_temp_slots (void)
1252 /* Pop a temporary nesting level. All slots in use in the current level
1256 pop_temp_slots (void)
1258 struct temp_slot *p;
1260 for (p = temp_slots; p; p = p->next)
1261 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1264 combine_temp_slots ();
1269 /* Initialize temporary slots. */
1272 init_temp_slots (void)
1274 /* We have not allocated any temporaries yet. */
1276 temp_slot_level = 0;
1277 var_temp_slot_level = 0;
1278 target_temp_slot_level = 0;
1281 /* Retroactively move an auto variable from a register to a stack
1282 slot. This is done when an address-reference to the variable is
1283 seen. If RESCAN is true, all previously emitted instructions are
1284 examined and modified to handle the fact that DECL is now
1288 put_var_into_stack (tree decl, int rescan)
1291 enum machine_mode promoted_mode, decl_mode;
1292 struct function *function = 0;
1294 int can_use_addressof;
1295 int volatilep = TREE_CODE (decl) != SAVE_EXPR && TREE_THIS_VOLATILE (decl);
1296 int usedp = (TREE_USED (decl)
1297 || (TREE_CODE (decl) != SAVE_EXPR && DECL_INITIAL (decl) != 0));
1299 context = decl_function_context (decl);
1301 /* Get the current rtl used for this object and its original mode. */
1302 reg = (TREE_CODE (decl) == SAVE_EXPR
1303 ? SAVE_EXPR_RTL (decl)
1304 : DECL_RTL_IF_SET (decl));
1306 /* No need to do anything if decl has no rtx yet
1307 since in that case caller is setting TREE_ADDRESSABLE
1308 and a stack slot will be assigned when the rtl is made. */
1312 /* Get the declared mode for this object. */
1313 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1314 : DECL_MODE (decl));
1315 /* Get the mode it's actually stored in. */
1316 promoted_mode = GET_MODE (reg);
1318 /* If this variable comes from an outer function, find that
1319 function's saved context. Don't use find_function_data here,
1320 because it might not be in any active function.
1321 FIXME: Is that really supposed to happen?
1322 It does in ObjC at least. */
1323 if (context != current_function_decl && context != inline_function_decl)
1324 for (function = outer_function_chain; function; function = function->outer)
1325 if (function->decl == context)
1328 /* If this is a variable-sized object or a structure passed by invisible
1329 reference, with a pseudo to address it, put that pseudo into the stack
1330 if the var is non-local. */
1331 if (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl)
1332 && GET_CODE (reg) == MEM
1333 && GET_CODE (XEXP (reg, 0)) == REG
1334 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1336 reg = XEXP (reg, 0);
1337 decl_mode = promoted_mode = GET_MODE (reg);
1340 /* If this variable lives in the current function and we don't need to put it
1341 in the stack for the sake of setjmp or the non-locality, try to keep it in
1342 a register until we know we actually need the address. */
1345 && ! (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl))
1347 /* FIXME make it work for promoted modes too */
1348 && decl_mode == promoted_mode
1349 #ifdef NON_SAVING_SETJMP
1350 && ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
1354 /* If we can't use ADDRESSOF, make sure we see through one we already
1356 if (! can_use_addressof && GET_CODE (reg) == MEM
1357 && GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
1358 reg = XEXP (XEXP (reg, 0), 0);
1360 /* Now we should have a value that resides in one or more pseudo regs. */
1362 if (GET_CODE (reg) == REG)
1364 if (can_use_addressof)
1365 gen_mem_addressof (reg, decl, rescan);
1367 put_reg_into_stack (function, reg, TREE_TYPE (decl), promoted_mode,
1368 decl_mode, volatilep, 0, usedp, 0);
1370 else if (GET_CODE (reg) == CONCAT)
1372 /* A CONCAT contains two pseudos; put them both in the stack.
1373 We do it so they end up consecutive.
1374 We fixup references to the parts only after we fixup references
1375 to the whole CONCAT, lest we do double fixups for the latter
1377 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1378 tree part_type = (*lang_hooks.types.type_for_mode) (part_mode, 0);
1379 rtx lopart = XEXP (reg, 0);
1380 rtx hipart = XEXP (reg, 1);
1381 #ifdef FRAME_GROWS_DOWNWARD
1382 /* Since part 0 should have a lower address, do it second. */
1383 put_reg_into_stack (function, hipart, part_type, part_mode,
1384 part_mode, volatilep, 0, 0, 0);
1385 put_reg_into_stack (function, lopart, part_type, part_mode,
1386 part_mode, volatilep, 0, 0, 0);
1388 put_reg_into_stack (function, lopart, part_type, part_mode,
1389 part_mode, volatilep, 0, 0, 0);
1390 put_reg_into_stack (function, hipart, part_type, part_mode,
1391 part_mode, volatilep, 0, 0, 0);
1394 /* Change the CONCAT into a combined MEM for both parts. */
1395 PUT_CODE (reg, MEM);
1396 MEM_ATTRS (reg) = 0;
1398 /* set_mem_attributes uses DECL_RTL to avoid re-generating of
1399 already computed alias sets. Here we want to re-generate. */
1401 SET_DECL_RTL (decl, NULL);
1402 set_mem_attributes (reg, decl, 1);
1404 SET_DECL_RTL (decl, reg);
1406 /* The two parts are in memory order already.
1407 Use the lower parts address as ours. */
1408 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1409 /* Prevent sharing of rtl that might lose. */
1410 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1411 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1412 if (usedp && rescan)
1414 schedule_fixup_var_refs (function, reg, TREE_TYPE (decl),
1416 schedule_fixup_var_refs (function, lopart, part_type, part_mode, 0);
1417 schedule_fixup_var_refs (function, hipart, part_type, part_mode, 0);
1424 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1425 into the stack frame of FUNCTION (0 means the current function).
1426 DECL_MODE is the machine mode of the user-level data type.
1427 PROMOTED_MODE is the machine mode of the register.
1428 VOLATILE_P is nonzero if this is for a "volatile" decl.
1429 USED_P is nonzero if this reg might have already been used in an insn. */
1432 put_reg_into_stack (struct function *function, rtx reg, tree type,
1433 enum machine_mode promoted_mode,
1434 enum machine_mode decl_mode, int volatile_p,
1435 unsigned int original_regno, int used_p, htab_t ht)
1437 struct function *func = function ? function : cfun;
1439 unsigned int regno = original_regno;
1442 regno = REGNO (reg);
1444 if (regno < func->x_max_parm_reg)
1446 if (!func->x_parm_reg_stack_loc)
1448 new = func->x_parm_reg_stack_loc[regno];
1452 new = assign_stack_local_1 (decl_mode, GET_MODE_SIZE (decl_mode), 0, func);
1454 PUT_CODE (reg, MEM);
1455 PUT_MODE (reg, decl_mode);
1456 XEXP (reg, 0) = XEXP (new, 0);
1457 MEM_ATTRS (reg) = 0;
1458 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1459 MEM_VOLATILE_P (reg) = volatile_p;
1461 /* If this is a memory ref that contains aggregate components,
1462 mark it as such for cse and loop optimize. If we are reusing a
1463 previously generated stack slot, then we need to copy the bit in
1464 case it was set for other reasons. For instance, it is set for
1465 __builtin_va_alist. */
1468 MEM_SET_IN_STRUCT_P (reg,
1469 AGGREGATE_TYPE_P (type) || MEM_IN_STRUCT_P (new));
1470 set_mem_alias_set (reg, get_alias_set (type));
1474 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht);
1477 /* Make sure that all refs to the variable, previously made
1478 when it was a register, are fixed up to be valid again.
1479 See function above for meaning of arguments. */
1482 schedule_fixup_var_refs (struct function *function, rtx reg, tree type,
1483 enum machine_mode promoted_mode, htab_t ht)
1485 int unsigned_p = type ? TREE_UNSIGNED (type) : 0;
1489 struct var_refs_queue *temp;
1491 temp = ggc_alloc (sizeof (struct var_refs_queue));
1492 temp->modified = reg;
1493 temp->promoted_mode = promoted_mode;
1494 temp->unsignedp = unsigned_p;
1495 temp->next = function->fixup_var_refs_queue;
1496 function->fixup_var_refs_queue = temp;
1499 /* Variable is local; fix it up now. */
1500 fixup_var_refs (reg, promoted_mode, unsigned_p, reg, ht);
1504 fixup_var_refs (rtx var, enum machine_mode promoted_mode, int unsignedp,
1505 rtx may_share, htab_t ht)
1508 rtx first_insn = get_insns ();
1509 struct sequence_stack *stack = seq_stack;
1510 tree rtl_exps = rtl_expr_chain;
1512 /* If there's a hash table, it must record all uses of VAR. */
1517 fixup_var_refs_insns_with_hash (ht, var, promoted_mode, unsignedp,
1522 fixup_var_refs_insns (first_insn, var, promoted_mode, unsignedp,
1523 stack == 0, may_share);
1525 /* Scan all pending sequences too. */
1526 for (; stack; stack = stack->next)
1528 push_to_full_sequence (stack->first, stack->last);
1529 fixup_var_refs_insns (stack->first, var, promoted_mode, unsignedp,
1530 stack->next != 0, may_share);
1531 /* Update remembered end of sequence
1532 in case we added an insn at the end. */
1533 stack->last = get_last_insn ();
1537 /* Scan all waiting RTL_EXPRs too. */
1538 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1540 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1541 if (seq != const0_rtx && seq != 0)
1543 push_to_sequence (seq);
1544 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1551 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1552 some part of an insn. Return a struct fixup_replacement whose OLD
1553 value is equal to X. Allocate a new structure if no such entry exists. */
1555 static struct fixup_replacement *
1556 find_fixup_replacement (struct fixup_replacement **replacements, rtx x)
1558 struct fixup_replacement *p;
1560 /* See if we have already replaced this. */
1561 for (p = *replacements; p != 0 && ! rtx_equal_p (p->old, x); p = p->next)
1566 p = xmalloc (sizeof (struct fixup_replacement));
1569 p->next = *replacements;
1576 /* Scan the insn-chain starting with INSN for refs to VAR and fix them
1577 up. TOPLEVEL is nonzero if this chain is the main chain of insns
1578 for the current function. MAY_SHARE is either a MEM that is not
1579 to be unshared or a list of them. */
1582 fixup_var_refs_insns (rtx insn, rtx var, enum machine_mode promoted_mode,
1583 int unsignedp, int toplevel, rtx may_share)
1587 /* fixup_var_refs_insn might modify insn, so save its next
1589 rtx next = NEXT_INSN (insn);
1591 /* CALL_PLACEHOLDERs are special; we have to switch into each of
1592 the three sequences they (potentially) contain, and process
1593 them recursively. The CALL_INSN itself is not interesting. */
1595 if (GET_CODE (insn) == CALL_INSN
1596 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
1600 /* Look at the Normal call, sibling call and tail recursion
1601 sequences attached to the CALL_PLACEHOLDER. */
1602 for (i = 0; i < 3; i++)
1604 rtx seq = XEXP (PATTERN (insn), i);
1607 push_to_sequence (seq);
1608 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1610 XEXP (PATTERN (insn), i) = get_insns ();
1616 else if (INSN_P (insn))
1617 fixup_var_refs_insn (insn, var, promoted_mode, unsignedp, toplevel,
1624 /* Look up the insns which reference VAR in HT and fix them up. Other
1625 arguments are the same as fixup_var_refs_insns.
1627 N.B. No need for special processing of CALL_PLACEHOLDERs here,
1628 because the hash table will point straight to the interesting insn
1629 (inside the CALL_PLACEHOLDER). */
1632 fixup_var_refs_insns_with_hash (htab_t ht, rtx var, enum machine_mode promoted_mode,
1633 int unsignedp, rtx may_share)
1635 struct insns_for_mem_entry tmp;
1636 struct insns_for_mem_entry *ime;
1640 ime = htab_find (ht, &tmp);
1641 for (insn_list = ime->insns; insn_list != 0; insn_list = XEXP (insn_list, 1))
1642 if (INSN_P (XEXP (insn_list, 0)))
1643 fixup_var_refs_insn (XEXP (insn_list, 0), var, promoted_mode,
1644 unsignedp, 1, may_share);
1648 /* Per-insn processing by fixup_var_refs_insns(_with_hash). INSN is
1649 the insn under examination, VAR is the variable to fix up
1650 references to, PROMOTED_MODE and UNSIGNEDP describe VAR, and
1651 TOPLEVEL is nonzero if this is the main insn chain for this
1655 fixup_var_refs_insn (rtx insn, rtx var, enum machine_mode promoted_mode,
1656 int unsignedp, int toplevel, rtx no_share)
1659 rtx set, prev, prev_set;
1662 /* Remember the notes in case we delete the insn. */
1663 note = REG_NOTES (insn);
1665 /* If this is a CLOBBER of VAR, delete it.
1667 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1668 and REG_RETVAL notes too. */
1669 if (GET_CODE (PATTERN (insn)) == CLOBBER
1670 && (XEXP (PATTERN (insn), 0) == var
1671 || (GET_CODE (XEXP (PATTERN (insn), 0)) == CONCAT
1672 && (XEXP (XEXP (PATTERN (insn), 0), 0) == var
1673 || XEXP (XEXP (PATTERN (insn), 0), 1) == var))))
1675 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1676 /* The REG_LIBCALL note will go away since we are going to
1677 turn INSN into a NOTE, so just delete the
1678 corresponding REG_RETVAL note. */
1679 remove_note (XEXP (note, 0),
1680 find_reg_note (XEXP (note, 0), REG_RETVAL,
1686 /* The insn to load VAR from a home in the arglist
1687 is now a no-op. When we see it, just delete it.
1688 Similarly if this is storing VAR from a register from which
1689 it was loaded in the previous insn. This will occur
1690 when an ADDRESSOF was made for an arglist slot. */
1692 && (set = single_set (insn)) != 0
1693 && SET_DEST (set) == var
1694 /* If this represents the result of an insn group,
1695 don't delete the insn. */
1696 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1697 && (rtx_equal_p (SET_SRC (set), var)
1698 || (GET_CODE (SET_SRC (set)) == REG
1699 && (prev = prev_nonnote_insn (insn)) != 0
1700 && (prev_set = single_set (prev)) != 0
1701 && SET_DEST (prev_set) == SET_SRC (set)
1702 && rtx_equal_p (SET_SRC (prev_set), var))))
1708 struct fixup_replacement *replacements = 0;
1709 rtx next_insn = NEXT_INSN (insn);
1711 if (SMALL_REGISTER_CLASSES)
1713 /* If the insn that copies the results of a CALL_INSN
1714 into a pseudo now references VAR, we have to use an
1715 intermediate pseudo since we want the life of the
1716 return value register to be only a single insn.
1718 If we don't use an intermediate pseudo, such things as
1719 address computations to make the address of VAR valid
1720 if it is not can be placed between the CALL_INSN and INSN.
1722 To make sure this doesn't happen, we record the destination
1723 of the CALL_INSN and see if the next insn uses both that
1726 if (call_dest != 0 && GET_CODE (insn) == INSN
1727 && reg_mentioned_p (var, PATTERN (insn))
1728 && reg_mentioned_p (call_dest, PATTERN (insn)))
1730 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1732 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1734 PATTERN (insn) = replace_rtx (PATTERN (insn),
1738 if (GET_CODE (insn) == CALL_INSN
1739 && GET_CODE (PATTERN (insn)) == SET)
1740 call_dest = SET_DEST (PATTERN (insn));
1741 else if (GET_CODE (insn) == CALL_INSN
1742 && GET_CODE (PATTERN (insn)) == PARALLEL
1743 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1744 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1749 /* See if we have to do anything to INSN now that VAR is in
1750 memory. If it needs to be loaded into a pseudo, use a single
1751 pseudo for the entire insn in case there is a MATCH_DUP
1752 between two operands. We pass a pointer to the head of
1753 a list of struct fixup_replacements. If fixup_var_refs_1
1754 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1755 it will record them in this list.
1757 If it allocated a pseudo for any replacement, we copy into
1760 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1761 &replacements, no_share);
1763 /* If this is last_parm_insn, and any instructions were output
1764 after it to fix it up, then we must set last_parm_insn to
1765 the last such instruction emitted. */
1766 if (insn == last_parm_insn)
1767 last_parm_insn = PREV_INSN (next_insn);
1769 while (replacements)
1771 struct fixup_replacement *next;
1773 if (GET_CODE (replacements->new) == REG)
1778 /* OLD might be a (subreg (mem)). */
1779 if (GET_CODE (replacements->old) == SUBREG)
1781 = fixup_memory_subreg (replacements->old, insn,
1785 = fixup_stack_1 (replacements->old, insn);
1787 insert_before = insn;
1789 /* If we are changing the mode, do a conversion.
1790 This might be wasteful, but combine.c will
1791 eliminate much of the waste. */
1793 if (GET_MODE (replacements->new)
1794 != GET_MODE (replacements->old))
1797 convert_move (replacements->new,
1798 replacements->old, unsignedp);
1803 seq = gen_move_insn (replacements->new,
1806 emit_insn_before (seq, insert_before);
1809 next = replacements->next;
1810 free (replacements);
1811 replacements = next;
1815 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1816 But don't touch other insns referred to by reg-notes;
1817 we will get them elsewhere. */
1820 if (GET_CODE (note) != INSN_LIST)
1822 = walk_fixup_memory_subreg (XEXP (note, 0), insn,
1824 note = XEXP (note, 1);
1828 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1829 See if the rtx expression at *LOC in INSN needs to be changed.
1831 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1832 contain a list of original rtx's and replacements. If we find that we need
1833 to modify this insn by replacing a memory reference with a pseudo or by
1834 making a new MEM to implement a SUBREG, we consult that list to see if
1835 we have already chosen a replacement. If none has already been allocated,
1836 we allocate it and update the list. fixup_var_refs_insn will copy VAR
1837 or the SUBREG, as appropriate, to the pseudo. */
1840 fixup_var_refs_1 (rtx var, enum machine_mode promoted_mode, rtx *loc, rtx insn,
1841 struct fixup_replacement **replacements, rtx no_share)
1845 RTX_CODE code = GET_CODE (x);
1848 struct fixup_replacement *replacement;
1853 if (XEXP (x, 0) == var)
1855 /* Prevent sharing of rtl that might lose. */
1856 rtx sub = copy_rtx (XEXP (var, 0));
1858 if (! validate_change (insn, loc, sub, 0))
1860 rtx y = gen_reg_rtx (GET_MODE (sub));
1863 /* We should be able to replace with a register or all is lost.
1864 Note that we can't use validate_change to verify this, since
1865 we're not caring for replacing all dups simultaneously. */
1866 if (! validate_replace_rtx (*loc, y, insn))
1869 /* Careful! First try to recognize a direct move of the
1870 value, mimicking how things are done in gen_reload wrt
1871 PLUS. Consider what happens when insn is a conditional
1872 move instruction and addsi3 clobbers flags. */
1875 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1879 if (recog_memoized (new_insn) < 0)
1881 /* That failed. Fall back on force_operand and hope. */
1884 sub = force_operand (sub, y);
1886 emit_insn (gen_move_insn (y, sub));
1892 /* Don't separate setter from user. */
1893 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1894 insn = PREV_INSN (insn);
1897 emit_insn_before (seq, insn);
1905 /* If we already have a replacement, use it. Otherwise,
1906 try to fix up this address in case it is invalid. */
1908 replacement = find_fixup_replacement (replacements, var);
1909 if (replacement->new)
1911 *loc = replacement->new;
1915 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1917 /* Unless we are forcing memory to register or we changed the mode,
1918 we can leave things the way they are if the insn is valid. */
1920 INSN_CODE (insn) = -1;
1921 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1922 && recog_memoized (insn) >= 0)
1925 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1929 /* If X contains VAR, we need to unshare it here so that we update
1930 each occurrence separately. But all identical MEMs in one insn
1931 must be replaced with the same rtx because of the possibility of
1934 if (reg_mentioned_p (var, x))
1936 replacement = find_fixup_replacement (replacements, x);
1937 if (replacement->new == 0)
1938 replacement->new = copy_most_rtx (x, no_share);
1940 *loc = x = replacement->new;
1941 code = GET_CODE (x);
1958 /* Note that in some cases those types of expressions are altered
1959 by optimize_bit_field, and do not survive to get here. */
1960 if (XEXP (x, 0) == var
1961 || (GET_CODE (XEXP (x, 0)) == SUBREG
1962 && SUBREG_REG (XEXP (x, 0)) == var))
1964 /* Get TEM as a valid MEM in the mode presently in the insn.
1966 We don't worry about the possibility of MATCH_DUP here; it
1967 is highly unlikely and would be tricky to handle. */
1970 if (GET_CODE (tem) == SUBREG)
1972 if (GET_MODE_BITSIZE (GET_MODE (tem))
1973 > GET_MODE_BITSIZE (GET_MODE (var)))
1975 replacement = find_fixup_replacement (replacements, var);
1976 if (replacement->new == 0)
1977 replacement->new = gen_reg_rtx (GET_MODE (var));
1978 SUBREG_REG (tem) = replacement->new;
1980 /* The following code works only if we have a MEM, so we
1981 need to handle the subreg here. We directly substitute
1982 it assuming that a subreg must be OK here. We already
1983 scheduled a replacement to copy the mem into the
1989 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
1992 tem = fixup_stack_1 (tem, insn);
1994 /* Unless we want to load from memory, get TEM into the proper mode
1995 for an extract from memory. This can only be done if the
1996 extract is at a constant position and length. */
1998 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
1999 && GET_CODE (XEXP (x, 2)) == CONST_INT
2000 && ! mode_dependent_address_p (XEXP (tem, 0))
2001 && ! MEM_VOLATILE_P (tem))
2003 enum machine_mode wanted_mode = VOIDmode;
2004 enum machine_mode is_mode = GET_MODE (tem);
2005 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2007 if (GET_CODE (x) == ZERO_EXTRACT)
2009 enum machine_mode new_mode
2010 = mode_for_extraction (EP_extzv, 1);
2011 if (new_mode != MAX_MACHINE_MODE)
2012 wanted_mode = new_mode;
2014 else if (GET_CODE (x) == SIGN_EXTRACT)
2016 enum machine_mode new_mode
2017 = mode_for_extraction (EP_extv, 1);
2018 if (new_mode != MAX_MACHINE_MODE)
2019 wanted_mode = new_mode;
2022 /* If we have a narrower mode, we can do something. */
2023 if (wanted_mode != VOIDmode
2024 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2026 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2027 rtx old_pos = XEXP (x, 2);
2030 /* If the bytes and bits are counted differently, we
2031 must adjust the offset. */
2032 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2033 offset = (GET_MODE_SIZE (is_mode)
2034 - GET_MODE_SIZE (wanted_mode) - offset);
2036 pos %= GET_MODE_BITSIZE (wanted_mode);
2038 newmem = adjust_address_nv (tem, wanted_mode, offset);
2040 /* Make the change and see if the insn remains valid. */
2041 INSN_CODE (insn) = -1;
2042 XEXP (x, 0) = newmem;
2043 XEXP (x, 2) = GEN_INT (pos);
2045 if (recog_memoized (insn) >= 0)
2048 /* Otherwise, restore old position. XEXP (x, 0) will be
2050 XEXP (x, 2) = old_pos;
2054 /* If we get here, the bitfield extract insn can't accept a memory
2055 reference. Copy the input into a register. */
2057 tem1 = gen_reg_rtx (GET_MODE (tem));
2058 emit_insn_before (gen_move_insn (tem1, tem), insn);
2065 if (SUBREG_REG (x) == var)
2067 /* If this is a special SUBREG made because VAR was promoted
2068 from a wider mode, replace it with VAR and call ourself
2069 recursively, this time saying that the object previously
2070 had its current mode (by virtue of the SUBREG). */
2072 if (SUBREG_PROMOTED_VAR_P (x))
2075 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements,
2080 /* If this SUBREG makes VAR wider, it has become a paradoxical
2081 SUBREG with VAR in memory, but these aren't allowed at this
2082 stage of the compilation. So load VAR into a pseudo and take
2083 a SUBREG of that pseudo. */
2084 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2086 replacement = find_fixup_replacement (replacements, var);
2087 if (replacement->new == 0)
2088 replacement->new = gen_reg_rtx (promoted_mode);
2089 SUBREG_REG (x) = replacement->new;
2093 /* See if we have already found a replacement for this SUBREG.
2094 If so, use it. Otherwise, make a MEM and see if the insn
2095 is recognized. If not, or if we should force MEM into a register,
2096 make a pseudo for this SUBREG. */
2097 replacement = find_fixup_replacement (replacements, x);
2098 if (replacement->new)
2100 enum machine_mode mode = GET_MODE (x);
2101 *loc = replacement->new;
2103 /* Careful! We may have just replaced a SUBREG by a MEM, which
2104 means that the insn may have become invalid again. We can't
2105 in this case make a new replacement since we already have one
2106 and we must deal with MATCH_DUPs. */
2107 if (GET_CODE (replacement->new) == MEM)
2109 INSN_CODE (insn) = -1;
2110 if (recog_memoized (insn) >= 0)
2113 fixup_var_refs_1 (replacement->new, mode, &PATTERN (insn),
2114 insn, replacements, no_share);
2120 replacement->new = *loc = fixup_memory_subreg (x, insn,
2123 INSN_CODE (insn) = -1;
2124 if (! flag_force_mem && recog_memoized (insn) >= 0)
2127 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2133 /* First do special simplification of bit-field references. */
2134 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2135 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2136 optimize_bit_field (x, insn, 0);
2137 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2138 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2139 optimize_bit_field (x, insn, 0);
2141 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2142 into a register and then store it back out. */
2143 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2144 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2145 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2146 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2147 > GET_MODE_SIZE (GET_MODE (var))))
2149 replacement = find_fixup_replacement (replacements, var);
2150 if (replacement->new == 0)
2151 replacement->new = gen_reg_rtx (GET_MODE (var));
2153 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2154 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2157 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2158 insn into a pseudo and store the low part of the pseudo into VAR. */
2159 if (GET_CODE (SET_DEST (x)) == SUBREG
2160 && SUBREG_REG (SET_DEST (x)) == var
2161 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2162 > GET_MODE_SIZE (GET_MODE (var))))
2164 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2165 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2172 rtx dest = SET_DEST (x);
2173 rtx src = SET_SRC (x);
2174 rtx outerdest = dest;
2176 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2177 || GET_CODE (dest) == SIGN_EXTRACT
2178 || GET_CODE (dest) == ZERO_EXTRACT)
2179 dest = XEXP (dest, 0);
2181 if (GET_CODE (src) == SUBREG)
2182 src = SUBREG_REG (src);
2184 /* If VAR does not appear at the top level of the SET
2185 just scan the lower levels of the tree. */
2187 if (src != var && dest != var)
2190 /* We will need to rerecognize this insn. */
2191 INSN_CODE (insn) = -1;
2193 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var
2194 && mode_for_extraction (EP_insv, -1) != MAX_MACHINE_MODE)
2196 /* Since this case will return, ensure we fixup all the
2198 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2199 insn, replacements, no_share);
2200 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2201 insn, replacements, no_share);
2202 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2203 insn, replacements, no_share);
2205 tem = XEXP (outerdest, 0);
2207 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2208 that may appear inside a ZERO_EXTRACT.
2209 This was legitimate when the MEM was a REG. */
2210 if (GET_CODE (tem) == SUBREG
2211 && SUBREG_REG (tem) == var)
2212 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2214 tem = fixup_stack_1 (tem, insn);
2216 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2217 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2218 && ! mode_dependent_address_p (XEXP (tem, 0))
2219 && ! MEM_VOLATILE_P (tem))
2221 enum machine_mode wanted_mode;
2222 enum machine_mode is_mode = GET_MODE (tem);
2223 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2225 wanted_mode = mode_for_extraction (EP_insv, 0);
2227 /* If we have a narrower mode, we can do something. */
2228 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2230 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2231 rtx old_pos = XEXP (outerdest, 2);
2234 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2235 offset = (GET_MODE_SIZE (is_mode)
2236 - GET_MODE_SIZE (wanted_mode) - offset);
2238 pos %= GET_MODE_BITSIZE (wanted_mode);
2240 newmem = adjust_address_nv (tem, wanted_mode, offset);
2242 /* Make the change and see if the insn remains valid. */
2243 INSN_CODE (insn) = -1;
2244 XEXP (outerdest, 0) = newmem;
2245 XEXP (outerdest, 2) = GEN_INT (pos);
2247 if (recog_memoized (insn) >= 0)
2250 /* Otherwise, restore old position. XEXP (x, 0) will be
2252 XEXP (outerdest, 2) = old_pos;
2256 /* If we get here, the bit-field store doesn't allow memory
2257 or isn't located at a constant position. Load the value into
2258 a register, do the store, and put it back into memory. */
2260 tem1 = gen_reg_rtx (GET_MODE (tem));
2261 emit_insn_before (gen_move_insn (tem1, tem), insn);
2262 emit_insn_after (gen_move_insn (tem, tem1), insn);
2263 XEXP (outerdest, 0) = tem1;
2267 /* STRICT_LOW_PART is a no-op on memory references
2268 and it can cause combinations to be unrecognizable,
2271 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2272 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2274 /* A valid insn to copy VAR into or out of a register
2275 must be left alone, to avoid an infinite loop here.
2276 If the reference to VAR is by a subreg, fix that up,
2277 since SUBREG is not valid for a memref.
2278 Also fix up the address of the stack slot.
2280 Note that we must not try to recognize the insn until
2281 after we know that we have valid addresses and no
2282 (subreg (mem ...) ...) constructs, since these interfere
2283 with determining the validity of the insn. */
2285 if ((SET_SRC (x) == var
2286 || (GET_CODE (SET_SRC (x)) == SUBREG
2287 && SUBREG_REG (SET_SRC (x)) == var))
2288 && (GET_CODE (SET_DEST (x)) == REG
2289 || (GET_CODE (SET_DEST (x)) == SUBREG
2290 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2291 && GET_MODE (var) == promoted_mode
2292 && x == single_set (insn))
2296 if (GET_CODE (SET_SRC (x)) == SUBREG
2297 && (GET_MODE_SIZE (GET_MODE (SET_SRC (x)))
2298 > GET_MODE_SIZE (GET_MODE (var))))
2300 /* This (subreg VAR) is now a paradoxical subreg. We need
2301 to replace VAR instead of the subreg. */
2302 replacement = find_fixup_replacement (replacements, var);
2303 if (replacement->new == NULL_RTX)
2304 replacement->new = gen_reg_rtx (GET_MODE (var));
2305 SUBREG_REG (SET_SRC (x)) = replacement->new;
2309 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2310 if (replacement->new)
2311 SET_SRC (x) = replacement->new;
2312 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2313 SET_SRC (x) = replacement->new
2314 = fixup_memory_subreg (SET_SRC (x), insn, promoted_mode,
2317 SET_SRC (x) = replacement->new
2318 = fixup_stack_1 (SET_SRC (x), insn);
2321 if (recog_memoized (insn) >= 0)
2324 /* INSN is not valid, but we know that we want to
2325 copy SET_SRC (x) to SET_DEST (x) in some way. So
2326 we generate the move and see whether it requires more
2327 than one insn. If it does, we emit those insns and
2328 delete INSN. Otherwise, we can just replace the pattern
2329 of INSN; we have already verified above that INSN has
2330 no other function that to do X. */
2332 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2333 if (NEXT_INSN (pat) != NULL_RTX)
2335 last = emit_insn_before (pat, insn);
2337 /* INSN might have REG_RETVAL or other important notes, so
2338 we need to store the pattern of the last insn in the
2339 sequence into INSN similarly to the normal case. LAST
2340 should not have REG_NOTES, but we allow them if INSN has
2342 if (REG_NOTES (last) && REG_NOTES (insn))
2344 if (REG_NOTES (last))
2345 REG_NOTES (insn) = REG_NOTES (last);
2346 PATTERN (insn) = PATTERN (last);
2351 PATTERN (insn) = PATTERN (pat);
2356 if ((SET_DEST (x) == var
2357 || (GET_CODE (SET_DEST (x)) == SUBREG
2358 && SUBREG_REG (SET_DEST (x)) == var))
2359 && (GET_CODE (SET_SRC (x)) == REG
2360 || (GET_CODE (SET_SRC (x)) == SUBREG
2361 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2362 && GET_MODE (var) == promoted_mode
2363 && x == single_set (insn))
2367 if (GET_CODE (SET_DEST (x)) == SUBREG)
2368 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn,
2371 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2373 if (recog_memoized (insn) >= 0)
2376 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2377 if (NEXT_INSN (pat) != NULL_RTX)
2379 last = emit_insn_before (pat, insn);
2381 /* INSN might have REG_RETVAL or other important notes, so
2382 we need to store the pattern of the last insn in the
2383 sequence into INSN similarly to the normal case. LAST
2384 should not have REG_NOTES, but we allow them if INSN has
2386 if (REG_NOTES (last) && REG_NOTES (insn))
2388 if (REG_NOTES (last))
2389 REG_NOTES (insn) = REG_NOTES (last);
2390 PATTERN (insn) = PATTERN (last);
2395 PATTERN (insn) = PATTERN (pat);
2400 /* Otherwise, storing into VAR must be handled specially
2401 by storing into a temporary and copying that into VAR
2402 with a new insn after this one. Note that this case
2403 will be used when storing into a promoted scalar since
2404 the insn will now have different modes on the input
2405 and output and hence will be invalid (except for the case
2406 of setting it to a constant, which does not need any
2407 change if it is valid). We generate extra code in that case,
2408 but combine.c will eliminate it. */
2413 rtx fixeddest = SET_DEST (x);
2414 enum machine_mode temp_mode;
2416 /* STRICT_LOW_PART can be discarded, around a MEM. */
2417 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2418 fixeddest = XEXP (fixeddest, 0);
2419 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2420 if (GET_CODE (fixeddest) == SUBREG)
2422 fixeddest = fixup_memory_subreg (fixeddest, insn,
2424 temp_mode = GET_MODE (fixeddest);
2428 fixeddest = fixup_stack_1 (fixeddest, insn);
2429 temp_mode = promoted_mode;
2432 temp = gen_reg_rtx (temp_mode);
2434 emit_insn_after (gen_move_insn (fixeddest,
2435 gen_lowpart (GET_MODE (fixeddest),
2439 SET_DEST (x) = temp;
2447 /* Nothing special about this RTX; fix its operands. */
2449 fmt = GET_RTX_FORMAT (code);
2450 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2453 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements,
2455 else if (fmt[i] == 'E')
2458 for (j = 0; j < XVECLEN (x, i); j++)
2459 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2460 insn, replacements, no_share);
2465 /* Previously, X had the form (SUBREG:m1 (REG:PROMOTED_MODE ...)).
2466 The REG was placed on the stack, so X now has the form (SUBREG:m1
2469 Return an rtx (MEM:m1 newaddr) which is equivalent. If any insns
2470 must be emitted to compute NEWADDR, put them before INSN.
2472 UNCRITICAL nonzero means accept paradoxical subregs.
2473 This is used for subregs found inside REG_NOTES. */
2476 fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode, int uncritical)
2479 rtx mem = SUBREG_REG (x);
2480 rtx addr = XEXP (mem, 0);
2481 enum machine_mode mode = GET_MODE (x);
2484 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2485 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (mem)) && ! uncritical)
2488 offset = SUBREG_BYTE (x);
2489 if (BYTES_BIG_ENDIAN)
2490 /* If the PROMOTED_MODE is wider than the mode of the MEM, adjust
2491 the offset so that it points to the right location within the
2493 offset -= (GET_MODE_SIZE (promoted_mode) - GET_MODE_SIZE (GET_MODE (mem)));
2495 if (!flag_force_addr
2496 && memory_address_p (mode, plus_constant (addr, offset)))
2497 /* Shortcut if no insns need be emitted. */
2498 return adjust_address (mem, mode, offset);
2501 result = adjust_address (mem, mode, offset);
2505 emit_insn_before (seq, insn);
2509 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2510 Replace subexpressions of X in place.
2511 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2512 Otherwise return X, with its contents possibly altered.
2514 INSN, PROMOTED_MODE and UNCRITICAL are as for
2515 fixup_memory_subreg. */
2518 walk_fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode,
2528 code = GET_CODE (x);
2530 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2531 return fixup_memory_subreg (x, insn, promoted_mode, uncritical);
2533 /* Nothing special about this RTX; fix its operands. */
2535 fmt = GET_RTX_FORMAT (code);
2536 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2539 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn,
2540 promoted_mode, uncritical);
2541 else if (fmt[i] == 'E')
2544 for (j = 0; j < XVECLEN (x, i); j++)
2546 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn,
2547 promoted_mode, uncritical);
2553 /* For each memory ref within X, if it refers to a stack slot
2554 with an out of range displacement, put the address in a temp register
2555 (emitting new insns before INSN to load these registers)
2556 and alter the memory ref to use that register.
2557 Replace each such MEM rtx with a copy, to avoid clobberage. */
2560 fixup_stack_1 (rtx x, rtx insn)
2563 RTX_CODE code = GET_CODE (x);
2568 rtx ad = XEXP (x, 0);
2569 /* If we have address of a stack slot but it's not valid
2570 (displacement is too large), compute the sum in a register. */
2571 if (GET_CODE (ad) == PLUS
2572 && GET_CODE (XEXP (ad, 0)) == REG
2573 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2574 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2575 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2576 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2577 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2579 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2580 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2581 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2582 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2585 if (memory_address_p (GET_MODE (x), ad))
2589 temp = copy_to_reg (ad);
2592 emit_insn_before (seq, insn);
2593 return replace_equiv_address (x, temp);
2598 fmt = GET_RTX_FORMAT (code);
2599 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2602 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2603 else if (fmt[i] == 'E')
2606 for (j = 0; j < XVECLEN (x, i); j++)
2607 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2613 /* Optimization: a bit-field instruction whose field
2614 happens to be a byte or halfword in memory
2615 can be changed to a move instruction.
2617 We call here when INSN is an insn to examine or store into a bit-field.
2618 BODY is the SET-rtx to be altered.
2620 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2621 (Currently this is called only from function.c, and EQUIV_MEM
2625 optimize_bit_field (rtx body, rtx insn, rtx *equiv_mem)
2630 enum machine_mode mode;
2632 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2633 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2634 bitfield = SET_DEST (body), destflag = 1;
2636 bitfield = SET_SRC (body), destflag = 0;
2638 /* First check that the field being stored has constant size and position
2639 and is in fact a byte or halfword suitably aligned. */
2641 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2642 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2643 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2645 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2649 /* Now check that the containing word is memory, not a register,
2650 and that it is safe to change the machine mode. */
2652 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2653 memref = XEXP (bitfield, 0);
2654 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2656 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2657 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2658 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2659 memref = SUBREG_REG (XEXP (bitfield, 0));
2660 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2662 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2663 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2666 && ! mode_dependent_address_p (XEXP (memref, 0))
2667 && ! MEM_VOLATILE_P (memref))
2669 /* Now adjust the address, first for any subreg'ing
2670 that we are now getting rid of,
2671 and then for which byte of the word is wanted. */
2673 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2676 /* Adjust OFFSET to count bits from low-address byte. */
2677 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2678 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2679 - offset - INTVAL (XEXP (bitfield, 1)));
2681 /* Adjust OFFSET to count bytes from low-address byte. */
2682 offset /= BITS_PER_UNIT;
2683 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2685 offset += (SUBREG_BYTE (XEXP (bitfield, 0))
2686 / UNITS_PER_WORD) * UNITS_PER_WORD;
2687 if (BYTES_BIG_ENDIAN)
2688 offset -= (MIN (UNITS_PER_WORD,
2689 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2690 - MIN (UNITS_PER_WORD,
2691 GET_MODE_SIZE (GET_MODE (memref))));
2695 memref = adjust_address (memref, mode, offset);
2696 insns = get_insns ();
2698 emit_insn_before (insns, insn);
2700 /* Store this memory reference where
2701 we found the bit field reference. */
2705 validate_change (insn, &SET_DEST (body), memref, 1);
2706 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2708 rtx src = SET_SRC (body);
2709 while (GET_CODE (src) == SUBREG
2710 && SUBREG_BYTE (src) == 0)
2711 src = SUBREG_REG (src);
2712 if (GET_MODE (src) != GET_MODE (memref))
2713 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2714 validate_change (insn, &SET_SRC (body), src, 1);
2716 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2717 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2718 /* This shouldn't happen because anything that didn't have
2719 one of these modes should have got converted explicitly
2720 and then referenced through a subreg.
2721 This is so because the original bit-field was
2722 handled by agg_mode and so its tree structure had
2723 the same mode that memref now has. */
2728 rtx dest = SET_DEST (body);
2730 while (GET_CODE (dest) == SUBREG
2731 && SUBREG_BYTE (dest) == 0
2732 && (GET_MODE_CLASS (GET_MODE (dest))
2733 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2734 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2736 dest = SUBREG_REG (dest);
2738 validate_change (insn, &SET_DEST (body), dest, 1);
2740 if (GET_MODE (dest) == GET_MODE (memref))
2741 validate_change (insn, &SET_SRC (body), memref, 1);
2744 /* Convert the mem ref to the destination mode. */
2745 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2748 convert_move (newreg, memref,
2749 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2753 validate_change (insn, &SET_SRC (body), newreg, 1);
2757 /* See if we can convert this extraction or insertion into
2758 a simple move insn. We might not be able to do so if this
2759 was, for example, part of a PARALLEL.
2761 If we succeed, write out any needed conversions. If we fail,
2762 it is hard to guess why we failed, so don't do anything
2763 special; just let the optimization be suppressed. */
2765 if (apply_change_group () && seq)
2766 emit_insn_before (seq, insn);
2771 /* These routines are responsible for converting virtual register references
2772 to the actual hard register references once RTL generation is complete.
2774 The following four variables are used for communication between the
2775 routines. They contain the offsets of the virtual registers from their
2776 respective hard registers. */
2778 static int in_arg_offset;
2779 static int var_offset;
2780 static int dynamic_offset;
2781 static int out_arg_offset;
2782 static int cfa_offset;
2784 /* In most machines, the stack pointer register is equivalent to the bottom
2787 #ifndef STACK_POINTER_OFFSET
2788 #define STACK_POINTER_OFFSET 0
2791 /* If not defined, pick an appropriate default for the offset of dynamically
2792 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2793 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2795 #ifndef STACK_DYNAMIC_OFFSET
2797 /* The bottom of the stack points to the actual arguments. If
2798 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2799 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2800 stack space for register parameters is not pushed by the caller, but
2801 rather part of the fixed stack areas and hence not included in
2802 `current_function_outgoing_args_size'. Nevertheless, we must allow
2803 for it when allocating stack dynamic objects. */
2805 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2806 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2807 ((ACCUMULATE_OUTGOING_ARGS \
2808 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2809 + (STACK_POINTER_OFFSET)) \
2812 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2813 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2814 + (STACK_POINTER_OFFSET))
2818 /* On most machines, the CFA coincides with the first incoming parm. */
2820 #ifndef ARG_POINTER_CFA_OFFSET
2821 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2824 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just
2825 had its address taken. DECL is the decl or SAVE_EXPR for the
2826 object stored in the register, for later use if we do need to force
2827 REG into the stack. REG is overwritten by the MEM like in
2828 put_reg_into_stack. RESCAN is true if previously emitted
2829 instructions must be rescanned and modified now that the REG has
2830 been transformed. */
2833 gen_mem_addressof (rtx reg, tree decl, int rescan)
2835 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2838 /* Calculate this before we start messing with decl's RTL. */
2839 HOST_WIDE_INT set = decl ? get_alias_set (decl) : 0;
2841 /* If the original REG was a user-variable, then so is the REG whose
2842 address is being taken. Likewise for unchanging. */
2843 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2844 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2846 PUT_CODE (reg, MEM);
2847 MEM_ATTRS (reg) = 0;
2852 tree type = TREE_TYPE (decl);
2853 enum machine_mode decl_mode
2854 = (DECL_P (decl) ? DECL_MODE (decl) : TYPE_MODE (TREE_TYPE (decl)));
2855 rtx decl_rtl = (TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl)
2856 : DECL_RTL_IF_SET (decl));
2858 PUT_MODE (reg, decl_mode);
2860 /* Clear DECL_RTL momentarily so functions below will work
2861 properly, then set it again. */
2862 if (DECL_P (decl) && decl_rtl == reg)
2863 SET_DECL_RTL (decl, 0);
2865 set_mem_attributes (reg, decl, 1);
2866 set_mem_alias_set (reg, set);
2868 if (DECL_P (decl) && decl_rtl == reg)
2869 SET_DECL_RTL (decl, reg);
2872 && (TREE_USED (decl) || (DECL_P (decl) && DECL_INITIAL (decl) != 0)))
2873 fixup_var_refs (reg, GET_MODE (reg), TREE_UNSIGNED (type), reg, 0);
2877 /* This can only happen during reload. Clear the same flag bits as
2879 MEM_VOLATILE_P (reg) = 0;
2880 RTX_UNCHANGING_P (reg) = 0;
2881 MEM_IN_STRUCT_P (reg) = 0;
2882 MEM_SCALAR_P (reg) = 0;
2883 MEM_ATTRS (reg) = 0;
2885 fixup_var_refs (reg, GET_MODE (reg), 0, reg, 0);
2891 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2894 flush_addressof (tree decl)
2896 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2897 && DECL_RTL (decl) != 0
2898 && GET_CODE (DECL_RTL (decl)) == MEM
2899 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2900 && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == REG)
2901 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2904 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2907 put_addressof_into_stack (rtx r, htab_t ht)
2910 int volatile_p, used_p;
2912 rtx reg = XEXP (r, 0);
2914 if (GET_CODE (reg) != REG)
2917 decl = ADDRESSOF_DECL (r);
2920 type = TREE_TYPE (decl);
2921 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2922 && TREE_THIS_VOLATILE (decl));
2923 used_p = (TREE_USED (decl)
2924 || (DECL_P (decl) && DECL_INITIAL (decl) != 0));
2933 put_reg_into_stack (0, reg, type, GET_MODE (reg), GET_MODE (reg),
2934 volatile_p, ADDRESSOF_REGNO (r), used_p, ht);
2937 /* List of replacements made below in purge_addressof_1 when creating
2938 bitfield insertions. */
2939 static rtx purge_bitfield_addressof_replacements;
2941 /* List of replacements made below in purge_addressof_1 for patterns
2942 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2943 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2944 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
2945 enough in complex cases, e.g. when some field values can be
2946 extracted by usage MEM with narrower mode. */
2947 static rtx purge_addressof_replacements;
2949 /* Helper function for purge_addressof. See if the rtx expression at *LOC
2950 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
2951 the stack. If the function returns FALSE then the replacement could not
2952 be made. If MAY_POSTPONE is true and we would not put the addressof
2953 to stack, postpone processing of the insn. */
2956 purge_addressof_1 (rtx *loc, rtx insn, int force, int store, int may_postpone,
2964 bool libcall = false;
2966 /* Re-start here to avoid recursion in common cases. */
2973 /* Is this a libcall? */
2975 libcall = REG_NOTE_KIND (*loc) == REG_RETVAL;
2977 code = GET_CODE (x);
2979 /* If we don't return in any of the cases below, we will recurse inside
2980 the RTX, which will normally result in any ADDRESSOF being forced into
2984 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1,
2986 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0,
2990 else if (code == ADDRESSOF)
2994 if (GET_CODE (XEXP (x, 0)) != MEM)
2995 put_addressof_into_stack (x, ht);
2997 /* We must create a copy of the rtx because it was created by
2998 overwriting a REG rtx which is always shared. */
2999 sub = copy_rtx (XEXP (XEXP (x, 0), 0));
3000 if (validate_change (insn, loc, sub, 0)
3001 || validate_replace_rtx (x, sub, insn))
3006 /* If SUB is a hard or virtual register, try it as a pseudo-register.
3007 Otherwise, perhaps SUB is an expression, so generate code to compute
3009 if (GET_CODE (sub) == REG && REGNO (sub) <= LAST_VIRTUAL_REGISTER)
3010 sub = copy_to_reg (sub);
3012 sub = force_operand (sub, NULL_RTX);
3014 if (! validate_change (insn, loc, sub, 0)
3015 && ! validate_replace_rtx (x, sub, insn))
3018 insns = get_insns ();
3020 emit_insn_before (insns, insn);
3024 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
3026 rtx sub = XEXP (XEXP (x, 0), 0);
3028 if (GET_CODE (sub) == MEM)
3029 sub = adjust_address_nv (sub, GET_MODE (x), 0);
3030 else if (GET_CODE (sub) == REG
3031 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
3033 else if (GET_CODE (sub) == REG && GET_MODE (x) != GET_MODE (sub))
3035 int size_x, size_sub;
3039 /* Postpone for now, so that we do not emit bitfield arithmetics
3040 unless there is some benefit from it. */
3041 if (!postponed_insns || XEXP (postponed_insns, 0) != insn)
3042 postponed_insns = alloc_INSN_LIST (insn, postponed_insns);
3048 /* When processing REG_NOTES look at the list of
3049 replacements done on the insn to find the register that X
3053 for (tem = purge_bitfield_addressof_replacements;
3055 tem = XEXP (XEXP (tem, 1), 1))
3056 if (rtx_equal_p (x, XEXP (tem, 0)))
3058 *loc = XEXP (XEXP (tem, 1), 0);
3062 /* See comment for purge_addressof_replacements. */
3063 for (tem = purge_addressof_replacements;
3065 tem = XEXP (XEXP (tem, 1), 1))
3066 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3068 rtx z = XEXP (XEXP (tem, 1), 0);
3070 if (GET_MODE (x) == GET_MODE (z)
3071 || (GET_CODE (XEXP (XEXP (tem, 1), 0)) != REG
3072 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3075 /* It can happen that the note may speak of things
3076 in a wider (or just different) mode than the
3077 code did. This is especially true of
3080 if (GET_CODE (z) == SUBREG && SUBREG_BYTE (z) == 0)
3083 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3084 && (GET_MODE_SIZE (GET_MODE (x))
3085 > GET_MODE_SIZE (GET_MODE (z))))
3087 /* This can occur as a result in invalid
3088 pointer casts, e.g. float f; ...
3089 *(long long int *)&f.
3090 ??? We could emit a warning here, but
3091 without a line number that wouldn't be
3093 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3096 z = gen_lowpart (GET_MODE (x), z);
3102 /* When we are processing the REG_NOTES of the last instruction
3103 of a libcall, there will be typically no replacements
3104 for that insn; the replacements happened before, piecemeal
3105 fashion. OTOH we are not interested in the details of
3106 this for the REG_EQUAL note, we want to know the big picture,
3107 which can be succinctly described with a simple SUBREG.
3108 Note that removing the REG_EQUAL note is not an option
3109 on the last insn of a libcall, so we must do a replacement. */
3111 /* In compile/990107-1.c:7 compiled at -O1 -m1 for sh-elf,
3113 (mem:DI (addressof:SI (reg/v:DF 160) 159 0x401c8510)
3114 [0 S8 A32]), which can be expressed with a simple
3116 if ((GET_MODE_SIZE (GET_MODE (x))
3117 <= GET_MODE_SIZE (GET_MODE (sub)))
3118 /* Again, invalid pointer casts (as in
3119 compile/990203-1.c) can require paradoxical
3121 || (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3122 && (GET_MODE_SIZE (GET_MODE (x))
3123 > GET_MODE_SIZE (GET_MODE (sub)))
3126 *loc = gen_rtx_SUBREG (GET_MODE (x), sub, 0);
3129 /* ??? Are there other cases we should handle? */
3131 /* Sometimes we may not be able to find the replacement. For
3132 example when the original insn was a MEM in a wider mode,
3133 and the note is part of a sign extension of a narrowed
3134 version of that MEM. Gcc testcase compile/990829-1.c can
3135 generate an example of this situation. Rather than complain
3136 we return false, which will prompt our caller to remove the
3141 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3142 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3144 /* Do not frob unchanging MEMs. If a later reference forces the
3145 pseudo to the stack, we can wind up with multiple writes to
3146 an unchanging memory, which is invalid. */
3147 if (RTX_UNCHANGING_P (x) && size_x != size_sub)
3150 /* Don't even consider working with paradoxical subregs,
3151 or the moral equivalent seen here. */
3152 else if (size_x <= size_sub
3153 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3155 /* Do a bitfield insertion to mirror what would happen
3162 rtx p = PREV_INSN (insn);
3165 val = gen_reg_rtx (GET_MODE (x));
3166 if (! validate_change (insn, loc, val, 0))
3168 /* Discard the current sequence and put the
3169 ADDRESSOF on stack. */
3175 emit_insn_before (seq, insn);
3176 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3180 store_bit_field (sub, size_x, 0, GET_MODE (x),
3181 val, GET_MODE_SIZE (GET_MODE (sub)));
3183 /* Make sure to unshare any shared rtl that store_bit_field
3184 might have created. */
3185 unshare_all_rtl_again (get_insns ());
3189 p = emit_insn_after (seq, insn);
3190 if (NEXT_INSN (insn))
3191 compute_insns_for_mem (NEXT_INSN (insn),
3192 p ? NEXT_INSN (p) : NULL_RTX,
3197 rtx p = PREV_INSN (insn);
3200 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3201 GET_MODE (x), GET_MODE (x),
3202 GET_MODE_SIZE (GET_MODE (sub)));
3204 if (! validate_change (insn, loc, val, 0))
3206 /* Discard the current sequence and put the
3207 ADDRESSOF on stack. */
3214 emit_insn_before (seq, insn);
3215 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3219 /* Remember the replacement so that the same one can be done
3220 on the REG_NOTES. */
3221 purge_bitfield_addressof_replacements
3222 = gen_rtx_EXPR_LIST (VOIDmode, x,
3225 purge_bitfield_addressof_replacements));
3227 /* We replaced with a reg -- all done. */
3232 else if (validate_change (insn, loc, sub, 0))
3234 /* Remember the replacement so that the same one can be done
3235 on the REG_NOTES. */
3236 if (GET_CODE (sub) == REG || GET_CODE (sub) == SUBREG)
3240 for (tem = purge_addressof_replacements;
3242 tem = XEXP (XEXP (tem, 1), 1))
3243 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3245 XEXP (XEXP (tem, 1), 0) = sub;
3248 purge_addressof_replacements
3249 = gen_rtx (EXPR_LIST, VOIDmode, XEXP (x, 0),
3250 gen_rtx_EXPR_LIST (VOIDmode, sub,
3251 purge_addressof_replacements));
3259 /* Scan all subexpressions. */
3260 fmt = GET_RTX_FORMAT (code);
3261 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3264 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0,
3266 else if (*fmt == 'E')
3267 for (j = 0; j < XVECLEN (x, i); j++)
3268 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0,
3275 /* Return a hash value for K, a REG. */
3278 insns_for_mem_hash (const void *k)
3280 /* Use the address of the key for the hash value. */
3281 struct insns_for_mem_entry *m = (struct insns_for_mem_entry *) k;
3282 return htab_hash_pointer (m->key);
3285 /* Return nonzero if K1 and K2 (two REGs) are the same. */
3288 insns_for_mem_comp (const void *k1, const void *k2)
3290 struct insns_for_mem_entry *m1 = (struct insns_for_mem_entry *) k1;
3291 struct insns_for_mem_entry *m2 = (struct insns_for_mem_entry *) k2;
3292 return m1->key == m2->key;
3295 struct insns_for_mem_walk_info
3297 /* The hash table that we are using to record which INSNs use which
3301 /* The INSN we are currently processing. */
3304 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3305 to find the insns that use the REGs in the ADDRESSOFs. */
3309 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3310 that might be used in an ADDRESSOF expression, record this INSN in
3311 the hash table given by DATA (which is really a pointer to an
3312 insns_for_mem_walk_info structure). */
3315 insns_for_mem_walk (rtx *r, void *data)
3317 struct insns_for_mem_walk_info *ifmwi
3318 = (struct insns_for_mem_walk_info *) data;
3319 struct insns_for_mem_entry tmp;
3320 tmp.insns = NULL_RTX;
3322 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3323 && GET_CODE (XEXP (*r, 0)) == REG)
3326 tmp.key = XEXP (*r, 0);
3327 e = htab_find_slot (ifmwi->ht, &tmp, INSERT);
3330 *e = ggc_alloc (sizeof (tmp));
3331 memcpy (*e, &tmp, sizeof (tmp));
3334 else if (ifmwi->pass == 1 && *r && GET_CODE (*r) == REG)
3336 struct insns_for_mem_entry *ifme;
3338 ifme = htab_find (ifmwi->ht, &tmp);
3340 /* If we have not already recorded this INSN, do so now. Since
3341 we process the INSNs in order, we know that if we have
3342 recorded it it must be at the front of the list. */
3343 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3344 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3351 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3352 which REGs in HT. */
3355 compute_insns_for_mem (rtx insns, rtx last_insn, htab_t ht)
3358 struct insns_for_mem_walk_info ifmwi;
3361 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3362 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3366 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3370 /* Helper function for purge_addressof called through for_each_rtx.
3371 Returns true iff the rtl is an ADDRESSOF. */
3374 is_addressof (rtx *rtl, void *data ATTRIBUTE_UNUSED)
3376 return GET_CODE (*rtl) == ADDRESSOF;
3379 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3380 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3384 purge_addressof (rtx insns)
3389 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3390 requires a fixup pass over the instruction stream to correct
3391 INSNs that depended on the REG being a REG, and not a MEM. But,
3392 these fixup passes are slow. Furthermore, most MEMs are not
3393 mentioned in very many instructions. So, we speed up the process
3394 by pre-calculating which REGs occur in which INSNs; that allows
3395 us to perform the fixup passes much more quickly. */
3396 ht = htab_create_ggc (1000, insns_for_mem_hash, insns_for_mem_comp, NULL);
3397 compute_insns_for_mem (insns, NULL_RTX, ht);
3399 postponed_insns = NULL;
3401 for (insn = insns; insn; insn = NEXT_INSN (insn))
3404 if (! purge_addressof_1 (&PATTERN (insn), insn,
3405 asm_noperands (PATTERN (insn)) > 0, 0, 1, ht))
3406 /* If we could not replace the ADDRESSOFs in the insn,
3407 something is wrong. */
3410 if (! purge_addressof_1 (®_NOTES (insn), NULL_RTX, 0, 0, 0, ht))
3412 /* If we could not replace the ADDRESSOFs in the insn's notes,
3413 we can just remove the offending notes instead. */
3416 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3418 /* If we find a REG_RETVAL note then the insn is a libcall.
3419 Such insns must have REG_EQUAL notes as well, in order
3420 for later passes of the compiler to work. So it is not
3421 safe to delete the notes here, and instead we abort. */
3422 if (REG_NOTE_KIND (note) == REG_RETVAL)
3424 if (for_each_rtx (¬e, is_addressof, NULL))
3425 remove_note (insn, note);
3430 /* Process the postponed insns. */
3431 while (postponed_insns)
3433 insn = XEXP (postponed_insns, 0);
3434 tmp = postponed_insns;
3435 postponed_insns = XEXP (postponed_insns, 1);
3436 free_INSN_LIST_node (tmp);
3438 if (! purge_addressof_1 (&PATTERN (insn), insn,
3439 asm_noperands (PATTERN (insn)) > 0, 0, 0, ht))
3444 purge_bitfield_addressof_replacements = 0;
3445 purge_addressof_replacements = 0;
3447 /* REGs are shared. purge_addressof will destructively replace a REG
3448 with a MEM, which creates shared MEMs.
3450 Unfortunately, the children of put_reg_into_stack assume that MEMs
3451 referring to the same stack slot are shared (fixup_var_refs and
3452 the associated hash table code).
3454 So, we have to do another unsharing pass after we have flushed any
3455 REGs that had their address taken into the stack.
3457 It may be worth tracking whether or not we converted any REGs into
3458 MEMs to avoid this overhead when it is not needed. */
3459 unshare_all_rtl_again (get_insns ());
3462 /* Convert a SET of a hard subreg to a set of the appropriate hard
3463 register. A subroutine of purge_hard_subreg_sets. */
3466 purge_single_hard_subreg_set (rtx pattern)
3468 rtx reg = SET_DEST (pattern);
3469 enum machine_mode mode = GET_MODE (SET_DEST (pattern));
3472 if (GET_CODE (reg) == SUBREG && GET_CODE (SUBREG_REG (reg)) == REG
3473 && REGNO (SUBREG_REG (reg)) < FIRST_PSEUDO_REGISTER)
3475 offset = subreg_regno_offset (REGNO (SUBREG_REG (reg)),
3476 GET_MODE (SUBREG_REG (reg)),
3479 reg = SUBREG_REG (reg);
3483 if (GET_CODE (reg) == REG && REGNO (reg) < FIRST_PSEUDO_REGISTER)
3485 reg = gen_rtx_REG (mode, REGNO (reg) + offset);
3486 SET_DEST (pattern) = reg;
3490 /* Eliminate all occurrences of SETs of hard subregs from INSNS. The
3491 only such SETs that we expect to see are those left in because
3492 integrate can't handle sets of parts of a return value register.
3494 We don't use alter_subreg because we only want to eliminate subregs
3495 of hard registers. */
3498 purge_hard_subreg_sets (rtx insn)
3500 for (; insn; insn = NEXT_INSN (insn))
3504 rtx pattern = PATTERN (insn);
3505 switch (GET_CODE (pattern))
3508 if (GET_CODE (SET_DEST (pattern)) == SUBREG)
3509 purge_single_hard_subreg_set (pattern);
3514 for (j = XVECLEN (pattern, 0) - 1; j >= 0; j--)
3516 rtx inner_pattern = XVECEXP (pattern, 0, j);
3517 if (GET_CODE (inner_pattern) == SET
3518 && GET_CODE (SET_DEST (inner_pattern)) == SUBREG)
3519 purge_single_hard_subreg_set (inner_pattern);
3530 /* Pass through the INSNS of function FNDECL and convert virtual register
3531 references to hard register references. */
3534 instantiate_virtual_regs (tree fndecl, rtx insns)
3539 /* Compute the offsets to use for this function. */
3540 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
3541 var_offset = STARTING_FRAME_OFFSET;
3542 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
3543 out_arg_offset = STACK_POINTER_OFFSET;
3544 cfa_offset = ARG_POINTER_CFA_OFFSET (fndecl);
3546 /* Scan all variables and parameters of this function. For each that is
3547 in memory, instantiate all virtual registers if the result is a valid
3548 address. If not, we do it later. That will handle most uses of virtual
3549 regs on many machines. */
3550 instantiate_decls (fndecl, 1);
3552 /* Initialize recognition, indicating that volatile is OK. */
3555 /* Scan through all the insns, instantiating every virtual register still
3557 for (insn = insns; insn; insn = NEXT_INSN (insn))
3558 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3559 || GET_CODE (insn) == CALL_INSN)
3561 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3562 if (INSN_DELETED_P (insn))
3564 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
3565 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
3566 if (GET_CODE (insn) == CALL_INSN)
3567 instantiate_virtual_regs_1 (&CALL_INSN_FUNCTION_USAGE (insn),
3570 /* Past this point all ASM statements should match. Verify that
3571 to avoid failures later in the compilation process. */
3572 if (asm_noperands (PATTERN (insn)) >= 0
3573 && ! check_asm_operands (PATTERN (insn)))
3574 instantiate_virtual_regs_lossage (insn);
3577 /* Instantiate the stack slots for the parm registers, for later use in
3578 addressof elimination. */
3579 for (i = 0; i < max_parm_reg; ++i)
3580 if (parm_reg_stack_loc[i])
3581 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3583 /* Now instantiate the remaining register equivalences for debugging info.
3584 These will not be valid addresses. */
3585 instantiate_decls (fndecl, 0);
3587 /* Indicate that, from now on, assign_stack_local should use
3588 frame_pointer_rtx. */
3589 virtuals_instantiated = 1;
3592 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3593 all virtual registers in their DECL_RTL's.
3595 If VALID_ONLY, do this only if the resulting address is still valid.
3596 Otherwise, always do it. */
3599 instantiate_decls (tree fndecl, int valid_only)
3603 /* Process all parameters of the function. */
3604 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3606 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3607 HOST_WIDE_INT size_rtl;
3609 instantiate_decl (DECL_RTL (decl), size, valid_only);
3611 /* If the parameter was promoted, then the incoming RTL mode may be
3612 larger than the declared type size. We must use the larger of
3614 size_rtl = GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl)));
3615 size = MAX (size_rtl, size);
3616 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3619 /* Now process all variables defined in the function or its subblocks. */
3620 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3623 /* Subroutine of instantiate_decls: Process all decls in the given
3624 BLOCK node and all its subblocks. */
3627 instantiate_decls_1 (tree let, int valid_only)
3631 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3632 if (DECL_RTL_SET_P (t))
3633 instantiate_decl (DECL_RTL (t),
3634 int_size_in_bytes (TREE_TYPE (t)),
3637 /* Process all subblocks. */
3638 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3639 instantiate_decls_1 (t, valid_only);
3642 /* Subroutine of the preceding procedures: Given RTL representing a
3643 decl and the size of the object, do any instantiation required.
3645 If VALID_ONLY is nonzero, it means that the RTL should only be
3646 changed if the new address is valid. */
3649 instantiate_decl (rtx x, HOST_WIDE_INT size, int valid_only)
3651 enum machine_mode mode;
3654 /* If this is not a MEM, no need to do anything. Similarly if the
3655 address is a constant or a register that is not a virtual register. */
3657 if (x == 0 || GET_CODE (x) != MEM)
3661 if (CONSTANT_P (addr)
3662 || (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == REG)
3663 || (GET_CODE (addr) == REG
3664 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3665 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3668 /* If we should only do this if the address is valid, copy the address.
3669 We need to do this so we can undo any changes that might make the
3670 address invalid. This copy is unfortunate, but probably can't be
3674 addr = copy_rtx (addr);
3676 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3678 if (valid_only && size >= 0)
3680 unsigned HOST_WIDE_INT decl_size = size;
3682 /* Now verify that the resulting address is valid for every integer or
3683 floating-point mode up to and including SIZE bytes long. We do this
3684 since the object might be accessed in any mode and frame addresses
3687 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3688 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3689 mode = GET_MODE_WIDER_MODE (mode))
3690 if (! memory_address_p (mode, addr))
3693 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3694 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3695 mode = GET_MODE_WIDER_MODE (mode))
3696 if (! memory_address_p (mode, addr))
3700 /* Put back the address now that we have updated it and we either know
3701 it is valid or we don't care whether it is valid. */
3706 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
3707 is a virtual register, return the equivalent hard register and set the
3708 offset indirectly through the pointer. Otherwise, return 0. */
3711 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
3714 HOST_WIDE_INT offset;
3716 if (x == virtual_incoming_args_rtx)
3717 new = arg_pointer_rtx, offset = in_arg_offset;
3718 else if (x == virtual_stack_vars_rtx)
3719 new = frame_pointer_rtx, offset = var_offset;
3720 else if (x == virtual_stack_dynamic_rtx)
3721 new = stack_pointer_rtx, offset = dynamic_offset;
3722 else if (x == virtual_outgoing_args_rtx)
3723 new = stack_pointer_rtx, offset = out_arg_offset;
3724 else if (x == virtual_cfa_rtx)
3725 new = arg_pointer_rtx, offset = cfa_offset;
3734 /* Called when instantiate_virtual_regs has failed to update the instruction.
3735 Usually this means that non-matching instruction has been emit, however for
3736 asm statements it may be the problem in the constraints. */
3738 instantiate_virtual_regs_lossage (rtx insn)
3740 if (asm_noperands (PATTERN (insn)) >= 0)
3742 error_for_asm (insn, "impossible constraint in `asm'");
3748 /* Given a pointer to a piece of rtx and an optional pointer to the
3749 containing object, instantiate any virtual registers present in it.
3751 If EXTRA_INSNS, we always do the replacement and generate
3752 any extra insns before OBJECT. If it zero, we do nothing if replacement
3755 Return 1 if we either had nothing to do or if we were able to do the
3756 needed replacement. Return 0 otherwise; we only return zero if
3757 EXTRA_INSNS is zero.
3759 We first try some simple transformations to avoid the creation of extra
3763 instantiate_virtual_regs_1 (rtx *loc, rtx object, int extra_insns)
3768 HOST_WIDE_INT offset = 0;
3774 /* Re-start here to avoid recursion in common cases. */
3781 /* We may have detected and deleted invalid asm statements. */
3782 if (object && INSN_P (object) && INSN_DELETED_P (object))
3785 code = GET_CODE (x);
3787 /* Check for some special cases. */
3805 /* We are allowed to set the virtual registers. This means that
3806 the actual register should receive the source minus the
3807 appropriate offset. This is used, for example, in the handling
3808 of non-local gotos. */
3809 if ((new = instantiate_new_reg (SET_DEST (x), &offset)) != 0)
3811 rtx src = SET_SRC (x);
3813 /* We are setting the register, not using it, so the relevant
3814 offset is the negative of the offset to use were we using
3817 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3819 /* The only valid sources here are PLUS or REG. Just do
3820 the simplest possible thing to handle them. */
3821 if (GET_CODE (src) != REG && GET_CODE (src) != PLUS)
3823 instantiate_virtual_regs_lossage (object);
3828 if (GET_CODE (src) != REG)
3829 temp = force_operand (src, NULL_RTX);
3832 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3836 emit_insn_before (seq, object);
3839 if (! validate_change (object, &SET_SRC (x), temp, 0)
3841 instantiate_virtual_regs_lossage (object);
3846 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3851 /* Handle special case of virtual register plus constant. */
3852 if (CONSTANT_P (XEXP (x, 1)))
3854 rtx old, new_offset;
3856 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3857 if (GET_CODE (XEXP (x, 0)) == PLUS)
3859 if ((new = instantiate_new_reg (XEXP (XEXP (x, 0), 0), &offset)))
3861 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3863 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3872 #ifdef POINTERS_EXTEND_UNSIGNED
3873 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
3874 we can commute the PLUS and SUBREG because pointers into the
3875 frame are well-behaved. */
3876 else if (GET_CODE (XEXP (x, 0)) == SUBREG && GET_MODE (x) == ptr_mode
3877 && GET_CODE (XEXP (x, 1)) == CONST_INT
3879 = instantiate_new_reg (SUBREG_REG (XEXP (x, 0)),
3881 && validate_change (object, loc,
3882 plus_constant (gen_lowpart (ptr_mode,
3885 + INTVAL (XEXP (x, 1))),
3889 else if ((new = instantiate_new_reg (XEXP (x, 0), &offset)) == 0)
3891 /* We know the second operand is a constant. Unless the
3892 first operand is a REG (which has been already checked),
3893 it needs to be checked. */
3894 if (GET_CODE (XEXP (x, 0)) != REG)
3902 new_offset = plus_constant (XEXP (x, 1), offset);
3904 /* If the new constant is zero, try to replace the sum with just
3906 if (new_offset == const0_rtx
3907 && validate_change (object, loc, new, 0))
3910 /* Next try to replace the register and new offset.
3911 There are two changes to validate here and we can't assume that
3912 in the case of old offset equals new just changing the register
3913 will yield a valid insn. In the interests of a little efficiency,
3914 however, we only call validate change once (we don't queue up the
3915 changes and then call apply_change_group). */
3919 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3920 : (XEXP (x, 0) = new,
3921 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3929 /* Otherwise copy the new constant into a register and replace
3930 constant with that register. */
3931 temp = gen_reg_rtx (Pmode);
3933 if (validate_change (object, &XEXP (x, 1), temp, 0))
3934 emit_insn_before (gen_move_insn (temp, new_offset), object);
3937 /* If that didn't work, replace this expression with a
3938 register containing the sum. */
3941 new = gen_rtx_PLUS (Pmode, new, new_offset);
3944 temp = force_operand (new, NULL_RTX);
3948 emit_insn_before (seq, object);
3949 if (! validate_change (object, loc, temp, 0)
3950 && ! validate_replace_rtx (x, temp, object))
3952 instantiate_virtual_regs_lossage (object);
3961 /* Fall through to generic two-operand expression case. */
3967 case DIV: case UDIV:
3968 case MOD: case UMOD:
3969 case AND: case IOR: case XOR:
3970 case ROTATERT: case ROTATE:
3971 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
3973 case GE: case GT: case GEU: case GTU:
3974 case LE: case LT: case LEU: case LTU:
3975 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
3976 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
3981 /* Most cases of MEM that convert to valid addresses have already been
3982 handled by our scan of decls. The only special handling we
3983 need here is to make a copy of the rtx to ensure it isn't being
3984 shared if we have to change it to a pseudo.
3986 If the rtx is a simple reference to an address via a virtual register,
3987 it can potentially be shared. In such cases, first try to make it
3988 a valid address, which can also be shared. Otherwise, copy it and
3991 First check for common cases that need no processing. These are
3992 usually due to instantiation already being done on a previous instance
3996 if (CONSTANT_ADDRESS_P (temp)
3997 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3998 || temp == arg_pointer_rtx
4000 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4001 || temp == hard_frame_pointer_rtx
4003 || temp == frame_pointer_rtx)
4006 if (GET_CODE (temp) == PLUS
4007 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4008 && (XEXP (temp, 0) == frame_pointer_rtx
4009 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4010 || XEXP (temp, 0) == hard_frame_pointer_rtx
4012 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4013 || XEXP (temp, 0) == arg_pointer_rtx
4018 if (temp == virtual_stack_vars_rtx
4019 || temp == virtual_incoming_args_rtx
4020 || (GET_CODE (temp) == PLUS
4021 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4022 && (XEXP (temp, 0) == virtual_stack_vars_rtx
4023 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
4025 /* This MEM may be shared. If the substitution can be done without
4026 the need to generate new pseudos, we want to do it in place
4027 so all copies of the shared rtx benefit. The call below will
4028 only make substitutions if the resulting address is still
4031 Note that we cannot pass X as the object in the recursive call
4032 since the insn being processed may not allow all valid
4033 addresses. However, if we were not passed on object, we can
4034 only modify X without copying it if X will have a valid
4037 ??? Also note that this can still lose if OBJECT is an insn that
4038 has less restrictions on an address that some other insn.
4039 In that case, we will modify the shared address. This case
4040 doesn't seem very likely, though. One case where this could
4041 happen is in the case of a USE or CLOBBER reference, but we
4042 take care of that below. */
4044 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
4045 object ? object : x, 0))
4048 /* Otherwise make a copy and process that copy. We copy the entire
4049 RTL expression since it might be a PLUS which could also be
4051 *loc = x = copy_rtx (x);
4054 /* Fall through to generic unary operation case. */
4057 case STRICT_LOW_PART:
4059 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
4060 case SIGN_EXTEND: case ZERO_EXTEND:
4061 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
4062 case FLOAT: case FIX:
4063 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
4068 case POPCOUNT: case PARITY:
4069 /* These case either have just one operand or we know that we need not
4070 check the rest of the operands. */
4076 /* If the operand is a MEM, see if the change is a valid MEM. If not,
4077 go ahead and make the invalid one, but do it to a copy. For a REG,
4078 just make the recursive call, since there's no chance of a problem. */
4080 if ((GET_CODE (XEXP (x, 0)) == MEM
4081 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
4083 || (GET_CODE (XEXP (x, 0)) == REG
4084 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
4087 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
4092 /* Try to replace with a PLUS. If that doesn't work, compute the sum
4093 in front of this insn and substitute the temporary. */
4094 if ((new = instantiate_new_reg (x, &offset)) != 0)
4096 temp = plus_constant (new, offset);
4097 if (!validate_change (object, loc, temp, 0))
4103 temp = force_operand (temp, NULL_RTX);
4107 emit_insn_before (seq, object);
4108 if (! validate_change (object, loc, temp, 0)
4109 && ! validate_replace_rtx (x, temp, object))
4110 instantiate_virtual_regs_lossage (object);
4117 if (GET_CODE (XEXP (x, 0)) == REG)
4120 else if (GET_CODE (XEXP (x, 0)) == MEM)
4122 /* If we have a (addressof (mem ..)), do any instantiation inside
4123 since we know we'll be making the inside valid when we finally
4124 remove the ADDRESSOF. */
4125 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
4134 /* Scan all subexpressions. */
4135 fmt = GET_RTX_FORMAT (code);
4136 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
4139 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
4142 else if (*fmt == 'E')
4143 for (j = 0; j < XVECLEN (x, i); j++)
4144 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
4151 /* Optimization: assuming this function does not receive nonlocal gotos,
4152 delete the handlers for such, as well as the insns to establish
4153 and disestablish them. */
4156 delete_handlers (void)
4159 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4161 /* Delete the handler by turning off the flag that would
4162 prevent jump_optimize from deleting it.
4163 Also permit deletion of the nonlocal labels themselves
4164 if nothing local refers to them. */
4165 if (GET_CODE (insn) == CODE_LABEL)
4169 LABEL_PRESERVE_P (insn) = 0;
4171 /* Remove it from the nonlocal_label list, to avoid confusing
4173 for (t = nonlocal_labels, last_t = 0; t;
4174 last_t = t, t = TREE_CHAIN (t))
4175 if (DECL_RTL (TREE_VALUE (t)) == insn)
4180 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
4182 TREE_CHAIN (last_t) = TREE_CHAIN (t);
4185 if (GET_CODE (insn) == INSN)
4189 for (t = nonlocal_goto_handler_slots; t != 0; t = XEXP (t, 1))
4190 if (reg_mentioned_p (t, PATTERN (insn)))
4196 || (nonlocal_goto_stack_level != 0
4197 && reg_mentioned_p (nonlocal_goto_stack_level,
4199 delete_related_insns (insn);
4204 /* Return the first insn following those generated by `assign_parms'. */
4207 get_first_nonparm_insn (void)
4210 return NEXT_INSN (last_parm_insn);
4211 return get_insns ();
4214 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4215 This means a type for which function calls must pass an address to the
4216 function or get an address back from the function.
4217 EXP may be a type node or an expression (whose type is tested). */
4220 aggregate_value_p (tree exp, tree fntype)
4222 int i, regno, nregs;
4225 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4228 switch (TREE_CODE (fntype))
4231 fntype = get_callee_fndecl (fntype);
4232 fntype = fntype ? TREE_TYPE (fntype) : 0;
4235 fntype = TREE_TYPE (fntype);
4240 case IDENTIFIER_NODE:
4244 /* We don't expect other rtl types here. */
4248 if (TREE_CODE (type) == VOID_TYPE)
4250 if (targetm.calls.return_in_memory (type, fntype))
4252 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4253 and thus can't be returned in registers. */
4254 if (TREE_ADDRESSABLE (type))
4256 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4258 /* Make sure we have suitable call-clobbered regs to return
4259 the value in; if not, we must return it in memory. */
4260 reg = hard_function_value (type, 0, 0);
4262 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4264 if (GET_CODE (reg) != REG)
4267 regno = REGNO (reg);
4268 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
4269 for (i = 0; i < nregs; i++)
4270 if (! call_used_regs[regno + i])
4275 /* Assign RTL expressions to the function's parameters.
4276 This may involve copying them into registers and using
4277 those registers as the RTL for them. */
4280 assign_parms (tree fndecl)
4283 CUMULATIVE_ARGS args_so_far;
4284 /* Total space needed so far for args on the stack,
4285 given as a constant and a tree-expression. */
4286 struct args_size stack_args_size;
4287 tree fntype = TREE_TYPE (fndecl);
4288 tree fnargs = DECL_ARGUMENTS (fndecl), orig_fnargs;
4289 /* This is used for the arg pointer when referring to stack args. */
4290 rtx internal_arg_pointer;
4291 /* This is a dummy PARM_DECL that we used for the function result if
4292 the function returns a structure. */
4293 tree function_result_decl = 0;
4294 int varargs_setup = 0;
4295 int reg_parm_stack_space ATTRIBUTE_UNUSED = 0;
4296 rtx conversion_insns = 0;
4298 /* Nonzero if function takes extra anonymous args.
4299 This means the last named arg must be on the stack
4300 right before the anonymous ones. */
4302 = (TYPE_ARG_TYPES (fntype) != 0
4303 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4304 != void_type_node));
4306 current_function_stdarg = stdarg;
4308 /* If the reg that the virtual arg pointer will be translated into is
4309 not a fixed reg or is the stack pointer, make a copy of the virtual
4310 arg pointer, and address parms via the copy. The frame pointer is
4311 considered fixed even though it is not marked as such.
4313 The second time through, simply use ap to avoid generating rtx. */
4315 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4316 || ! (fixed_regs[ARG_POINTER_REGNUM]
4317 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4318 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4320 internal_arg_pointer = virtual_incoming_args_rtx;
4321 current_function_internal_arg_pointer = internal_arg_pointer;
4323 stack_args_size.constant = 0;
4324 stack_args_size.var = 0;
4326 /* If struct value address is treated as the first argument, make it so. */
4327 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
4328 && ! current_function_returns_pcc_struct
4329 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
4331 tree type = build_pointer_type (TREE_TYPE (fntype));
4333 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4335 DECL_ARG_TYPE (function_result_decl) = type;
4336 TREE_CHAIN (function_result_decl) = fnargs;
4337 fnargs = function_result_decl;
4340 orig_fnargs = fnargs;
4342 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4343 parm_reg_stack_loc = ggc_alloc_cleared (max_parm_reg * sizeof (rtx));
4345 /* If the target wants to split complex arguments into scalars, do so. */
4346 if (targetm.calls.split_complex_arg)
4347 fnargs = split_complex_args (fnargs);
4349 #ifdef REG_PARM_STACK_SPACE
4350 #ifdef MAYBE_REG_PARM_STACK_SPACE
4351 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
4353 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
4357 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4358 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4360 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, fndecl, -1);
4363 /* We haven't yet found an argument that we must push and pretend the
4365 current_function_pretend_args_size = 0;
4367 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4371 enum machine_mode promoted_mode, passed_mode;
4372 enum machine_mode nominal_mode, promoted_nominal_mode;
4374 struct locate_and_pad_arg_data locate;
4375 int passed_pointer = 0;
4376 int did_conversion = 0;
4377 tree passed_type = DECL_ARG_TYPE (parm);
4378 tree nominal_type = TREE_TYPE (parm);
4379 int last_named = 0, named_arg;
4382 int pretend_bytes = 0;
4384 /* Set LAST_NAMED if this is last named arg before last
4390 for (tem = TREE_CHAIN (parm); tem; tem = TREE_CHAIN (tem))
4391 if (DECL_NAME (tem))
4397 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4398 most machines, if this is a varargs/stdarg function, then we treat
4399 the last named arg as if it were anonymous too. */
4400 named_arg = targetm.calls.strict_argument_naming (&args_so_far) ? 1 : ! last_named;
4402 if (TREE_TYPE (parm) == error_mark_node
4403 /* This can happen after weird syntax errors
4404 or if an enum type is defined among the parms. */
4405 || TREE_CODE (parm) != PARM_DECL
4406 || passed_type == NULL)
4408 SET_DECL_RTL (parm, gen_rtx_MEM (BLKmode, const0_rtx));
4409 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4410 TREE_USED (parm) = 1;
4414 /* Find mode of arg as it is passed, and mode of arg
4415 as it should be during execution of this function. */
4416 passed_mode = TYPE_MODE (passed_type);
4417 nominal_mode = TYPE_MODE (nominal_type);
4419 /* If the parm's mode is VOID, its value doesn't matter,
4420 and avoid the usual things like emit_move_insn that could crash. */
4421 if (nominal_mode == VOIDmode)
4423 SET_DECL_RTL (parm, const0_rtx);
4424 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4428 /* If the parm is to be passed as a transparent union, use the
4429 type of the first field for the tests below. We have already
4430 verified that the modes are the same. */
4431 if (DECL_TRANSPARENT_UNION (parm)
4432 || (TREE_CODE (passed_type) == UNION_TYPE
4433 && TYPE_TRANSPARENT_UNION (passed_type)))
4434 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4436 /* See if this arg was passed by invisible reference. It is if
4437 it is an object whose size depends on the contents of the
4438 object itself or if the machine requires these objects be passed
4441 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (passed_type))
4442 || TREE_ADDRESSABLE (passed_type)
4443 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4444 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4445 passed_type, named_arg)
4449 passed_type = nominal_type = build_pointer_type (passed_type);
4451 passed_mode = nominal_mode = Pmode;
4453 /* See if the frontend wants to pass this by invisible reference. */
4454 else if (passed_type != nominal_type
4455 && POINTER_TYPE_P (passed_type)
4456 && TREE_TYPE (passed_type) == nominal_type)
4458 nominal_type = passed_type;
4460 passed_mode = nominal_mode = Pmode;
4463 promoted_mode = passed_mode;
4465 if (targetm.calls.promote_function_args (TREE_TYPE (fndecl)))
4467 /* Compute the mode in which the arg is actually extended to. */
4468 unsignedp = TREE_UNSIGNED (passed_type);
4469 promoted_mode = promote_mode (passed_type, promoted_mode, &unsignedp, 1);
4472 /* Let machine desc say which reg (if any) the parm arrives in.
4473 0 means it arrives on the stack. */
4474 #ifdef FUNCTION_INCOMING_ARG
4475 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4476 passed_type, named_arg);
4478 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4479 passed_type, named_arg);
4482 if (entry_parm == 0)
4483 promoted_mode = passed_mode;
4485 /* If this is the last named parameter, do any required setup for
4486 varargs or stdargs. We need to know about the case of this being an
4487 addressable type, in which case we skip the registers it
4488 would have arrived in.
4490 For stdargs, LAST_NAMED will be set for two parameters, the one that
4491 is actually the last named, and the dummy parameter. We only
4492 want to do this action once.
4494 Also, indicate when RTL generation is to be suppressed. */
4495 if (last_named && !varargs_setup)
4497 int varargs_pretend_bytes = 0;
4498 targetm.calls.setup_incoming_varargs (&args_so_far, promoted_mode,
4500 &varargs_pretend_bytes, 0);
4503 /* If the back-end has requested extra stack space, record how
4504 much is needed. Do not change pretend_args_size otherwise
4505 since it may be nonzero from an earlier partial argument. */
4506 if (varargs_pretend_bytes > 0)
4507 current_function_pretend_args_size = varargs_pretend_bytes;
4510 /* Determine parm's home in the stack,
4511 in case it arrives in the stack or we should pretend it did.
4513 Compute the stack position and rtx where the argument arrives
4516 There is one complexity here: If this was a parameter that would
4517 have been passed in registers, but wasn't only because it is
4518 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4519 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4520 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4521 0 as it was the previous time. */
4522 in_regs = entry_parm != 0;
4523 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4526 if (!in_regs && !named_arg)
4529 targetm.calls.pretend_outgoing_varargs_named (&args_so_far);
4532 #ifdef FUNCTION_INCOMING_ARG
4533 in_regs = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4535 pretend_named) != 0;
4537 in_regs = FUNCTION_ARG (args_so_far, promoted_mode,
4539 pretend_named) != 0;
4544 /* If this parameter was passed both in registers and in the stack,
4545 use the copy on the stack. */
4546 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4549 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4552 partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4553 passed_type, named_arg);
4555 #ifndef MAYBE_REG_PARM_STACK_SPACE
4556 /* The caller might already have allocated stack space
4557 for the register parameters. */
4558 && reg_parm_stack_space == 0
4562 /* Part of this argument is passed in registers and part
4563 is passed on the stack. Ask the prologue code to extend
4564 the stack part so that we can recreate the full value.
4566 PRETEND_BYTES is the size of the registers we need to store.
4567 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
4568 stack space that the prologue should allocate.
4570 Internally, gcc assumes that the argument pointer is
4571 aligned to STACK_BOUNDARY bits. This is used both for
4572 alignment optimizations (see init_emit) and to locate
4573 arguments that are aligned to more than PARM_BOUNDARY
4574 bits. We must preserve this invariant by rounding
4575 CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to a stack
4577 pretend_bytes = partial * UNITS_PER_WORD;
4578 current_function_pretend_args_size
4579 = CEIL_ROUND (pretend_bytes, STACK_BYTES);
4581 /* If PRETEND_BYTES != CURRENT_FUNCTION_PRETEND_ARGS_SIZE,
4582 insert the padding before the start of the first pretend
4584 stack_args_size.constant
4585 = (current_function_pretend_args_size - pretend_bytes);
4590 memset (&locate, 0, sizeof (locate));
4591 locate_and_pad_parm (promoted_mode, passed_type, in_regs,
4592 entry_parm ? partial : 0, fndecl,
4593 &stack_args_size, &locate);
4598 /* If we're passing this arg using a reg, make its stack home
4599 the aligned stack slot. */
4601 offset_rtx = ARGS_SIZE_RTX (locate.slot_offset);
4603 offset_rtx = ARGS_SIZE_RTX (locate.offset);
4605 if (offset_rtx == const0_rtx)
4606 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4608 stack_parm = gen_rtx_MEM (promoted_mode,
4609 gen_rtx_PLUS (Pmode,
4610 internal_arg_pointer,
4613 set_mem_attributes (stack_parm, parm, 1);
4614 set_mem_align (stack_parm,
4615 FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type));
4617 set_reg_attrs_for_parm (entry_parm, stack_parm);
4620 /* If this parm was passed part in regs and part in memory,
4621 pretend it arrived entirely in memory
4622 by pushing the register-part onto the stack.
4624 In the special case of a DImode or DFmode that is split,
4625 we could put it together in a pseudoreg directly,
4626 but for now that's not worth bothering with. */
4630 /* Handle calls that pass values in multiple non-contiguous
4631 locations. The Irix 6 ABI has examples of this. */
4632 if (GET_CODE (entry_parm) == PARALLEL)
4633 emit_group_store (validize_mem (stack_parm), entry_parm,
4635 int_size_in_bytes (TREE_TYPE (parm)));
4638 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
4641 entry_parm = stack_parm;
4644 /* If we didn't decide this parm came in a register,
4645 by default it came on the stack. */
4646 if (entry_parm == 0)
4647 entry_parm = stack_parm;
4649 /* Record permanently how this parm was passed. */
4650 DECL_INCOMING_RTL (parm) = entry_parm;
4652 /* If there is actually space on the stack for this parm,
4653 count it in stack_args_size; otherwise set stack_parm to 0
4654 to indicate there is no preallocated stack slot for the parm. */
4656 if (entry_parm == stack_parm
4657 || (GET_CODE (entry_parm) == PARALLEL
4658 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4659 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
4660 /* On some machines, even if a parm value arrives in a register
4661 there is still an (uninitialized) stack slot allocated for it.
4663 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
4664 whether this parameter already has a stack slot allocated,
4665 because an arg block exists only if current_function_args_size
4666 is larger than some threshold, and we haven't calculated that
4667 yet. So, for now, we just assume that stack slots never exist
4669 || REG_PARM_STACK_SPACE (fndecl) > 0
4673 stack_args_size.constant += pretend_bytes + locate.size.constant;
4674 if (locate.size.var)
4675 ADD_PARM_SIZE (stack_args_size, locate.size.var);
4678 /* No stack slot was pushed for this parm. */
4681 /* Update info on where next arg arrives in registers. */
4683 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4684 passed_type, named_arg);
4686 /* If we can't trust the parm stack slot to be aligned enough
4687 for its ultimate type, don't use that slot after entry.
4688 We'll make another stack slot, if we need one. */
4689 if (STRICT_ALIGNMENT && stack_parm
4690 && GET_MODE_ALIGNMENT (nominal_mode) > MEM_ALIGN (stack_parm))
4693 /* If parm was passed in memory, and we need to convert it on entry,
4694 don't store it back in that same slot. */
4695 if (entry_parm == stack_parm
4696 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4699 /* When an argument is passed in multiple locations, we can't
4700 make use of this information, but we can save some copying if
4701 the whole argument is passed in a single register. */
4702 if (GET_CODE (entry_parm) == PARALLEL
4703 && nominal_mode != BLKmode && passed_mode != BLKmode)
4705 int i, len = XVECLEN (entry_parm, 0);
4707 for (i = 0; i < len; i++)
4708 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
4709 && GET_CODE (XEXP (XVECEXP (entry_parm, 0, i), 0)) == REG
4710 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
4712 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
4714 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
4715 DECL_INCOMING_RTL (parm) = entry_parm;
4720 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4721 in the mode in which it arrives.
4722 STACK_PARM is an RTX for a stack slot where the parameter can live
4723 during the function (in case we want to put it there).
4724 STACK_PARM is 0 if no stack slot was pushed for it.
4726 Now output code if necessary to convert ENTRY_PARM to
4727 the type in which this function declares it,
4728 and store that result in an appropriate place,
4729 which may be a pseudo reg, may be STACK_PARM,
4730 or may be a local stack slot if STACK_PARM is 0.
4732 Set DECL_RTL to that place. */
4734 if (GET_CODE (entry_parm) == PARALLEL && nominal_mode != BLKmode
4735 && XVECLEN (entry_parm, 0) > 1)
4737 /* Reconstitute objects the size of a register or larger using
4738 register operations instead of the stack. */
4739 rtx parmreg = gen_reg_rtx (nominal_mode);
4741 if (REG_P (parmreg))
4743 unsigned int regno = REGNO (parmreg);
4745 emit_group_store (parmreg, entry_parm, TREE_TYPE (parm),
4746 int_size_in_bytes (TREE_TYPE (parm)));
4747 SET_DECL_RTL (parm, parmreg);
4749 if (regno >= max_parm_reg)
4752 int old_max_parm_reg = max_parm_reg;
4754 /* It's slow to expand this one register at a time,
4755 but it's also rare and we need max_parm_reg to be
4756 precisely correct. */
4757 max_parm_reg = regno + 1;
4758 new = ggc_realloc (parm_reg_stack_loc,
4759 max_parm_reg * sizeof (rtx));
4760 memset (new + old_max_parm_reg, 0,
4761 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
4762 parm_reg_stack_loc = new;
4763 parm_reg_stack_loc[regno] = stack_parm;
4768 if (nominal_mode == BLKmode
4769 #ifdef BLOCK_REG_PADDING
4770 || (locate.where_pad == (BYTES_BIG_ENDIAN ? upward : downward)
4771 && GET_MODE_SIZE (promoted_mode) < UNITS_PER_WORD)
4773 || GET_CODE (entry_parm) == PARALLEL)
4775 /* If a BLKmode arrives in registers, copy it to a stack slot.
4776 Handle calls that pass values in multiple non-contiguous
4777 locations. The Irix 6 ABI has examples of this. */
4778 if (GET_CODE (entry_parm) == REG
4779 || GET_CODE (entry_parm) == PARALLEL)
4781 int size = int_size_in_bytes (TREE_TYPE (parm));
4782 int size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
4785 /* Note that we will be storing an integral number of words.
4786 So we have to be careful to ensure that we allocate an
4787 integral number of words. We do this below in the
4788 assign_stack_local if space was not allocated in the argument
4789 list. If it was, this will not work if PARM_BOUNDARY is not
4790 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4791 if it becomes a problem. Exception is when BLKmode arrives
4792 with arguments not conforming to word_mode. */
4794 if (stack_parm == 0)
4796 stack_parm = assign_stack_local (BLKmode, size_stored, 0);
4797 PUT_MODE (stack_parm, GET_MODE (entry_parm));
4798 set_mem_attributes (stack_parm, parm, 1);
4800 else if (GET_CODE (entry_parm) == PARALLEL
4801 && GET_MODE(entry_parm) == BLKmode)
4803 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
4806 mem = validize_mem (stack_parm);
4808 /* Handle calls that pass values in multiple non-contiguous
4809 locations. The Irix 6 ABI has examples of this. */
4810 if (GET_CODE (entry_parm) == PARALLEL)
4811 emit_group_store (mem, entry_parm, TREE_TYPE (parm), size);
4816 /* If SIZE is that of a mode no bigger than a word, just use
4817 that mode's store operation. */
4818 else if (size <= UNITS_PER_WORD)
4820 enum machine_mode mode
4821 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
4824 #ifdef BLOCK_REG_PADDING
4825 && (size == UNITS_PER_WORD
4826 || (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4827 != (BYTES_BIG_ENDIAN ? upward : downward)))
4831 rtx reg = gen_rtx_REG (mode, REGNO (entry_parm));
4832 emit_move_insn (change_address (mem, mode, 0), reg);
4835 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
4836 machine must be aligned to the left before storing
4837 to memory. Note that the previous test doesn't
4838 handle all cases (e.g. SIZE == 3). */
4839 else if (size != UNITS_PER_WORD
4840 #ifdef BLOCK_REG_PADDING
4841 && (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4849 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4850 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
4852 x = expand_binop (word_mode, ashl_optab, reg,
4853 GEN_INT (by), 0, 1, OPTAB_WIDEN);
4854 tem = change_address (mem, word_mode, 0);
4855 emit_move_insn (tem, x);
4858 move_block_from_reg (REGNO (entry_parm), mem,
4859 size_stored / UNITS_PER_WORD);
4862 move_block_from_reg (REGNO (entry_parm), mem,
4863 size_stored / UNITS_PER_WORD);
4865 /* If parm is already bound to register pair, don't change
4867 if (! DECL_RTL_SET_P (parm))
4868 SET_DECL_RTL (parm, stack_parm);
4870 else if (! ((! optimize
4871 && ! DECL_REGISTER (parm))
4872 || TREE_SIDE_EFFECTS (parm)
4873 /* If -ffloat-store specified, don't put explicit
4874 float variables into registers. */
4875 || (flag_float_store
4876 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4877 /* Always assign pseudo to structure return or item passed
4878 by invisible reference. */
4879 || passed_pointer || parm == function_result_decl)
4881 /* Store the parm in a pseudoregister during the function, but we
4882 may need to do it in a wider mode. */
4885 unsigned int regno, regnoi = 0, regnor = 0;
4887 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
4889 promoted_nominal_mode
4890 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4892 parmreg = gen_reg_rtx (promoted_nominal_mode);
4893 mark_user_reg (parmreg);
4895 /* If this was an item that we received a pointer to, set DECL_RTL
4899 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)),
4901 set_mem_attributes (x, parm, 1);
4902 SET_DECL_RTL (parm, x);
4906 SET_DECL_RTL (parm, parmreg);
4907 maybe_set_unchanging (DECL_RTL (parm), parm);
4910 /* Copy the value into the register. */
4911 if (nominal_mode != passed_mode
4912 || promoted_nominal_mode != promoted_mode)
4915 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4916 mode, by the caller. We now have to convert it to
4917 NOMINAL_MODE, if different. However, PARMREG may be in
4918 a different mode than NOMINAL_MODE if it is being stored
4921 If ENTRY_PARM is a hard register, it might be in a register
4922 not valid for operating in its mode (e.g., an odd-numbered
4923 register for a DFmode). In that case, moves are the only
4924 thing valid, so we can't do a convert from there. This
4925 occurs when the calling sequence allow such misaligned
4928 In addition, the conversion may involve a call, which could
4929 clobber parameters which haven't been copied to pseudo
4930 registers yet. Therefore, we must first copy the parm to
4931 a pseudo reg here, and save the conversion until after all
4932 parameters have been moved. */
4934 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4936 emit_move_insn (tempreg, validize_mem (entry_parm));
4938 push_to_sequence (conversion_insns);
4939 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4941 if (GET_CODE (tempreg) == SUBREG
4942 && GET_MODE (tempreg) == nominal_mode
4943 && GET_CODE (SUBREG_REG (tempreg)) == REG
4944 && nominal_mode == passed_mode
4945 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (entry_parm)
4946 && GET_MODE_SIZE (GET_MODE (tempreg))
4947 < GET_MODE_SIZE (GET_MODE (entry_parm)))
4949 /* The argument is already sign/zero extended, so note it
4951 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
4952 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
4955 /* TREE_USED gets set erroneously during expand_assignment. */
4956 save_tree_used = TREE_USED (parm);
4957 expand_assignment (parm,
4958 make_tree (nominal_type, tempreg), 0);
4959 TREE_USED (parm) = save_tree_used;
4960 conversion_insns = get_insns ();
4965 emit_move_insn (parmreg, validize_mem (entry_parm));
4967 /* If we were passed a pointer but the actual value
4968 can safely live in a register, put it in one. */
4969 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4970 /* If by-reference argument was promoted, demote it. */
4971 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
4973 && ! DECL_REGISTER (parm))
4974 || TREE_SIDE_EFFECTS (parm)
4975 /* If -ffloat-store specified, don't put explicit
4976 float variables into registers. */
4977 || (flag_float_store
4978 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))))
4980 /* We can't use nominal_mode, because it will have been set to
4981 Pmode above. We must use the actual mode of the parm. */
4982 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
4983 mark_user_reg (parmreg);
4984 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
4986 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
4987 int unsigned_p = TREE_UNSIGNED (TREE_TYPE (parm));
4988 push_to_sequence (conversion_insns);
4989 emit_move_insn (tempreg, DECL_RTL (parm));
4991 convert_to_mode (GET_MODE (parmreg),
4994 emit_move_insn (parmreg, DECL_RTL (parm));
4995 conversion_insns = get_insns();
5000 emit_move_insn (parmreg, DECL_RTL (parm));
5001 SET_DECL_RTL (parm, parmreg);
5002 /* STACK_PARM is the pointer, not the parm, and PARMREG is
5006 #ifdef FUNCTION_ARG_CALLEE_COPIES
5007 /* If we are passed an arg by reference and it is our responsibility
5008 to make a copy, do it now.
5009 PASSED_TYPE and PASSED mode now refer to the pointer, not the
5010 original argument, so we must recreate them in the call to
5011 FUNCTION_ARG_CALLEE_COPIES. */
5012 /* ??? Later add code to handle the case that if the argument isn't
5013 modified, don't do the copy. */
5015 else if (passed_pointer
5016 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
5017 TYPE_MODE (TREE_TYPE (passed_type)),
5018 TREE_TYPE (passed_type),
5020 && ! TREE_ADDRESSABLE (TREE_TYPE (passed_type)))
5023 tree type = TREE_TYPE (passed_type);
5025 /* This sequence may involve a library call perhaps clobbering
5026 registers that haven't been copied to pseudos yet. */
5028 push_to_sequence (conversion_insns);
5030 if (!COMPLETE_TYPE_P (type)
5031 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5032 /* This is a variable sized object. */
5033 copy = gen_rtx_MEM (BLKmode,
5034 allocate_dynamic_stack_space
5035 (expr_size (parm), NULL_RTX,
5036 TYPE_ALIGN (type)));
5038 copy = assign_stack_temp (TYPE_MODE (type),
5039 int_size_in_bytes (type), 1);
5040 set_mem_attributes (copy, parm, 1);
5042 store_expr (parm, copy, 0);
5043 emit_move_insn (parmreg, XEXP (copy, 0));
5044 conversion_insns = get_insns ();
5048 #endif /* FUNCTION_ARG_CALLEE_COPIES */
5050 /* In any case, record the parm's desired stack location
5051 in case we later discover it must live in the stack.
5053 If it is a COMPLEX value, store the stack location for both
5056 if (GET_CODE (parmreg) == CONCAT)
5057 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
5059 regno = REGNO (parmreg);
5061 if (regno >= max_parm_reg)
5064 int old_max_parm_reg = max_parm_reg;
5066 /* It's slow to expand this one register at a time,
5067 but it's also rare and we need max_parm_reg to be
5068 precisely correct. */
5069 max_parm_reg = regno + 1;
5070 new = ggc_realloc (parm_reg_stack_loc,
5071 max_parm_reg * sizeof (rtx));
5072 memset (new + old_max_parm_reg, 0,
5073 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
5074 parm_reg_stack_loc = new;
5077 if (GET_CODE (parmreg) == CONCAT)
5079 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
5081 regnor = REGNO (gen_realpart (submode, parmreg));
5082 regnoi = REGNO (gen_imagpart (submode, parmreg));
5084 if (stack_parm != 0)
5086 parm_reg_stack_loc[regnor]
5087 = gen_realpart (submode, stack_parm);
5088 parm_reg_stack_loc[regnoi]
5089 = gen_imagpart (submode, stack_parm);
5093 parm_reg_stack_loc[regnor] = 0;
5094 parm_reg_stack_loc[regnoi] = 0;
5098 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
5100 /* Mark the register as eliminable if we did no conversion
5101 and it was copied from memory at a fixed offset,
5102 and the arg pointer was not copied to a pseudo-reg.
5103 If the arg pointer is a pseudo reg or the offset formed
5104 an invalid address, such memory-equivalences
5105 as we make here would screw up life analysis for it. */
5106 if (nominal_mode == passed_mode
5109 && GET_CODE (stack_parm) == MEM
5110 && locate.offset.var == 0
5111 && reg_mentioned_p (virtual_incoming_args_rtx,
5112 XEXP (stack_parm, 0)))
5114 rtx linsn = get_last_insn ();
5117 /* Mark complex types separately. */
5118 if (GET_CODE (parmreg) == CONCAT)
5119 /* Scan backwards for the set of the real and
5121 for (sinsn = linsn; sinsn != 0;
5122 sinsn = prev_nonnote_insn (sinsn))
5124 set = single_set (sinsn);
5126 && SET_DEST (set) == regno_reg_rtx [regnoi])
5128 = gen_rtx_EXPR_LIST (REG_EQUIV,
5129 parm_reg_stack_loc[regnoi],
5132 && SET_DEST (set) == regno_reg_rtx [regnor])
5134 = gen_rtx_EXPR_LIST (REG_EQUIV,
5135 parm_reg_stack_loc[regnor],
5138 else if ((set = single_set (linsn)) != 0
5139 && SET_DEST (set) == parmreg)
5141 = gen_rtx_EXPR_LIST (REG_EQUIV,
5142 stack_parm, REG_NOTES (linsn));
5145 /* For pointer data type, suggest pointer register. */
5146 if (POINTER_TYPE_P (TREE_TYPE (parm)))
5147 mark_reg_pointer (parmreg,
5148 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5150 /* If something wants our address, try to use ADDRESSOF. */
5151 if (TREE_ADDRESSABLE (parm))
5153 /* If we end up putting something into the stack,
5154 fixup_var_refs_insns will need to make a pass over
5155 all the instructions. It looks through the pending
5156 sequences -- but it can't see the ones in the
5157 CONVERSION_INSNS, if they're not on the sequence
5158 stack. So, we go back to that sequence, just so that
5159 the fixups will happen. */
5160 push_to_sequence (conversion_insns);
5161 put_var_into_stack (parm, /*rescan=*/true);
5162 conversion_insns = get_insns ();
5168 /* Value must be stored in the stack slot STACK_PARM
5169 during function execution. */
5171 if (promoted_mode != nominal_mode)
5173 /* Conversion is required. */
5174 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
5176 emit_move_insn (tempreg, validize_mem (entry_parm));
5178 push_to_sequence (conversion_insns);
5179 entry_parm = convert_to_mode (nominal_mode, tempreg,
5180 TREE_UNSIGNED (TREE_TYPE (parm)));
5182 /* ??? This may need a big-endian conversion on sparc64. */
5183 stack_parm = adjust_address (stack_parm, nominal_mode, 0);
5185 conversion_insns = get_insns ();
5190 if (entry_parm != stack_parm)
5192 if (stack_parm == 0)
5195 = assign_stack_local (GET_MODE (entry_parm),
5196 GET_MODE_SIZE (GET_MODE (entry_parm)),
5198 set_mem_attributes (stack_parm, parm, 1);
5201 if (promoted_mode != nominal_mode)
5203 push_to_sequence (conversion_insns);
5204 emit_move_insn (validize_mem (stack_parm),
5205 validize_mem (entry_parm));
5206 conversion_insns = get_insns ();
5210 emit_move_insn (validize_mem (stack_parm),
5211 validize_mem (entry_parm));
5214 SET_DECL_RTL (parm, stack_parm);
5218 if (targetm.calls.split_complex_arg && fnargs != orig_fnargs)
5220 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
5222 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
5223 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
5225 rtx tmp, real, imag;
5226 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
5228 real = DECL_RTL (fnargs);
5229 imag = DECL_RTL (TREE_CHAIN (fnargs));
5230 if (inner != GET_MODE (real))
5232 real = gen_lowpart_SUBREG (inner, real);
5233 imag = gen_lowpart_SUBREG (inner, imag);
5235 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5236 SET_DECL_RTL (parm, tmp);
5238 real = DECL_INCOMING_RTL (fnargs);
5239 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
5240 if (inner != GET_MODE (real))
5242 real = gen_lowpart_SUBREG (inner, real);
5243 imag = gen_lowpart_SUBREG (inner, imag);
5245 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5246 DECL_INCOMING_RTL (parm) = tmp;
5247 fnargs = TREE_CHAIN (fnargs);
5251 SET_DECL_RTL (parm, DECL_RTL (fnargs));
5252 DECL_INCOMING_RTL (parm) = DECL_INCOMING_RTL (fnargs);
5254 fnargs = TREE_CHAIN (fnargs);
5258 /* Output all parameter conversion instructions (possibly including calls)
5259 now that all parameters have been copied out of hard registers. */
5260 emit_insn (conversion_insns);
5262 /* If we are receiving a struct value address as the first argument, set up
5263 the RTL for the function result. As this might require code to convert
5264 the transmitted address to Pmode, we do this here to ensure that possible
5265 preliminary conversions of the address have been emitted already. */
5266 if (function_result_decl)
5268 tree result = DECL_RESULT (fndecl);
5269 rtx addr = DECL_RTL (function_result_decl);
5272 addr = convert_memory_address (Pmode, addr);
5273 x = gen_rtx_MEM (DECL_MODE (result), addr);
5274 set_mem_attributes (x, result, 1);
5275 SET_DECL_RTL (result, x);
5278 last_parm_insn = get_last_insn ();
5280 current_function_args_size = stack_args_size.constant;
5282 /* Adjust function incoming argument size for alignment and
5285 #ifdef REG_PARM_STACK_SPACE
5286 #ifndef MAYBE_REG_PARM_STACK_SPACE
5287 current_function_args_size = MAX (current_function_args_size,
5288 REG_PARM_STACK_SPACE (fndecl));
5292 current_function_args_size
5293 = ((current_function_args_size + STACK_BYTES - 1)
5294 / STACK_BYTES) * STACK_BYTES;
5296 #ifdef ARGS_GROW_DOWNWARD
5297 current_function_arg_offset_rtx
5298 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
5299 : expand_expr (size_diffop (stack_args_size.var,
5300 size_int (-stack_args_size.constant)),
5301 NULL_RTX, VOIDmode, 0));
5303 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
5306 /* See how many bytes, if any, of its args a function should try to pop
5309 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
5310 current_function_args_size);
5312 /* For stdarg.h function, save info about
5313 regs and stack space used by the named args. */
5315 current_function_args_info = args_so_far;
5317 /* Set the rtx used for the function return value. Put this in its
5318 own variable so any optimizers that need this information don't have
5319 to include tree.h. Do this here so it gets done when an inlined
5320 function gets output. */
5322 current_function_return_rtx
5323 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
5324 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
5326 /* If scalar return value was computed in a pseudo-reg, or was a named
5327 return value that got dumped to the stack, copy that to the hard
5329 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
5331 tree decl_result = DECL_RESULT (fndecl);
5332 rtx decl_rtl = DECL_RTL (decl_result);
5334 if (REG_P (decl_rtl)
5335 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5336 : DECL_REGISTER (decl_result))
5340 #ifdef FUNCTION_OUTGOING_VALUE
5341 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
5344 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
5347 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
5348 /* The delay slot scheduler assumes that current_function_return_rtx
5349 holds the hard register containing the return value, not a
5350 temporary pseudo. */
5351 current_function_return_rtx = real_decl_rtl;
5356 /* If ARGS contains entries with complex types, split the entry into two
5357 entries of the component type. Return a new list of substitutions are
5358 needed, else the old list. */
5361 split_complex_args (tree args)
5365 /* Before allocating memory, check for the common case of no complex. */
5366 for (p = args; p; p = TREE_CHAIN (p))
5368 tree type = TREE_TYPE (p);
5369 if (TREE_CODE (type) == COMPLEX_TYPE
5370 && targetm.calls.split_complex_arg (type))
5376 args = copy_list (args);
5378 for (p = args; p; p = TREE_CHAIN (p))
5380 tree type = TREE_TYPE (p);
5381 if (TREE_CODE (type) == COMPLEX_TYPE
5382 && targetm.calls.split_complex_arg (type))
5385 tree subtype = TREE_TYPE (type);
5387 /* Rewrite the PARM_DECL's type with its component. */
5388 TREE_TYPE (p) = subtype;
5389 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
5390 DECL_MODE (p) = VOIDmode;
5391 DECL_SIZE (p) = NULL;
5392 DECL_SIZE_UNIT (p) = NULL;
5395 /* Build a second synthetic decl. */
5396 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
5397 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
5398 layout_decl (decl, 0);
5400 /* Splice it in; skip the new decl. */
5401 TREE_CHAIN (decl) = TREE_CHAIN (p);
5402 TREE_CHAIN (p) = decl;
5410 /* Indicate whether REGNO is an incoming argument to the current function
5411 that was promoted to a wider mode. If so, return the RTX for the
5412 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
5413 that REGNO is promoted from and whether the promotion was signed or
5417 promoted_input_arg (unsigned int regno, enum machine_mode *pmode, int *punsignedp)
5421 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
5422 arg = TREE_CHAIN (arg))
5423 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
5424 && REGNO (DECL_INCOMING_RTL (arg)) == regno
5425 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
5427 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
5428 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
5430 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
5431 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
5432 && mode != DECL_MODE (arg))
5434 *pmode = DECL_MODE (arg);
5435 *punsignedp = unsignedp;
5436 return DECL_INCOMING_RTL (arg);
5444 /* Compute the size and offset from the start of the stacked arguments for a
5445 parm passed in mode PASSED_MODE and with type TYPE.
5447 INITIAL_OFFSET_PTR points to the current offset into the stacked
5450 The starting offset and size for this parm are returned in
5451 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
5452 nonzero, the offset is that of stack slot, which is returned in
5453 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
5454 padding required from the initial offset ptr to the stack slot.
5456 IN_REGS is nonzero if the argument will be passed in registers. It will
5457 never be set if REG_PARM_STACK_SPACE is not defined.
5459 FNDECL is the function in which the argument was defined.
5461 There are two types of rounding that are done. The first, controlled by
5462 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
5463 list to be aligned to the specific boundary (in bits). This rounding
5464 affects the initial and starting offsets, but not the argument size.
5466 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
5467 optionally rounds the size of the parm to PARM_BOUNDARY. The
5468 initial offset is not affected by this rounding, while the size always
5469 is and the starting offset may be. */
5471 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
5472 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
5473 callers pass in the total size of args so far as
5474 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
5477 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
5478 int partial, tree fndecl ATTRIBUTE_UNUSED,
5479 struct args_size *initial_offset_ptr,
5480 struct locate_and_pad_arg_data *locate)
5483 enum direction where_pad;
5485 int reg_parm_stack_space = 0;
5486 int part_size_in_regs;
5488 #ifdef REG_PARM_STACK_SPACE
5489 #ifdef MAYBE_REG_PARM_STACK_SPACE
5490 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
5492 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5495 /* If we have found a stack parm before we reach the end of the
5496 area reserved for registers, skip that area. */
5499 if (reg_parm_stack_space > 0)
5501 if (initial_offset_ptr->var)
5503 initial_offset_ptr->var
5504 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5505 ssize_int (reg_parm_stack_space));
5506 initial_offset_ptr->constant = 0;
5508 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5509 initial_offset_ptr->constant = reg_parm_stack_space;
5512 #endif /* REG_PARM_STACK_SPACE */
5514 part_size_in_regs = 0;
5515 if (reg_parm_stack_space == 0)
5516 part_size_in_regs = ((partial * UNITS_PER_WORD)
5517 / (PARM_BOUNDARY / BITS_PER_UNIT)
5518 * (PARM_BOUNDARY / BITS_PER_UNIT));
5521 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5522 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5523 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5524 locate->where_pad = where_pad;
5526 #ifdef ARGS_GROW_DOWNWARD
5527 locate->slot_offset.constant = -initial_offset_ptr->constant;
5528 if (initial_offset_ptr->var)
5529 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
5530 initial_offset_ptr->var);
5534 if (where_pad != none
5535 && (!host_integerp (sizetree, 1)
5536 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5537 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
5538 SUB_PARM_SIZE (locate->slot_offset, s2);
5541 locate->slot_offset.constant += part_size_in_regs;
5544 #ifdef REG_PARM_STACK_SPACE
5545 || REG_PARM_STACK_SPACE (fndecl) > 0
5548 pad_to_arg_alignment (&locate->slot_offset, boundary,
5549 &locate->alignment_pad);
5551 locate->size.constant = (-initial_offset_ptr->constant
5552 - locate->slot_offset.constant);
5553 if (initial_offset_ptr->var)
5554 locate->size.var = size_binop (MINUS_EXPR,
5555 size_binop (MINUS_EXPR,
5557 initial_offset_ptr->var),
5558 locate->slot_offset.var);
5560 /* Pad_below needs the pre-rounded size to know how much to pad
5562 locate->offset = locate->slot_offset;
5563 if (where_pad == downward)
5564 pad_below (&locate->offset, passed_mode, sizetree);
5566 #else /* !ARGS_GROW_DOWNWARD */
5568 #ifdef REG_PARM_STACK_SPACE
5569 || REG_PARM_STACK_SPACE (fndecl) > 0
5572 pad_to_arg_alignment (initial_offset_ptr, boundary,
5573 &locate->alignment_pad);
5574 locate->slot_offset = *initial_offset_ptr;
5576 #ifdef PUSH_ROUNDING
5577 if (passed_mode != BLKmode)
5578 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5581 /* Pad_below needs the pre-rounded size to know how much to pad below
5582 so this must be done before rounding up. */
5583 locate->offset = locate->slot_offset;
5584 if (where_pad == downward)
5585 pad_below (&locate->offset, passed_mode, sizetree);
5587 if (where_pad != none
5588 && (!host_integerp (sizetree, 1)
5589 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5590 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5592 ADD_PARM_SIZE (locate->size, sizetree);
5594 locate->size.constant -= part_size_in_regs;
5595 #endif /* ARGS_GROW_DOWNWARD */
5598 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5599 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5602 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
5603 struct args_size *alignment_pad)
5605 tree save_var = NULL_TREE;
5606 HOST_WIDE_INT save_constant = 0;
5607 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5608 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
5610 #ifdef SPARC_STACK_BOUNDARY_HACK
5611 /* The sparc port has a bug. It sometimes claims a STACK_BOUNDARY
5612 higher than the real alignment of %sp. However, when it does this,
5613 the alignment of %sp+STACK_POINTER_OFFSET will be STACK_BOUNDARY.
5614 This is a temporary hack while the sparc port is fixed. */
5615 if (SPARC_STACK_BOUNDARY_HACK)
5619 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5621 save_var = offset_ptr->var;
5622 save_constant = offset_ptr->constant;
5625 alignment_pad->var = NULL_TREE;
5626 alignment_pad->constant = 0;
5628 if (boundary > BITS_PER_UNIT)
5630 if (offset_ptr->var)
5632 tree sp_offset_tree = ssize_int (sp_offset);
5633 tree offset = size_binop (PLUS_EXPR,
5634 ARGS_SIZE_TREE (*offset_ptr),
5636 #ifdef ARGS_GROW_DOWNWARD
5637 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
5639 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
5642 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
5643 /* ARGS_SIZE_TREE includes constant term. */
5644 offset_ptr->constant = 0;
5645 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5646 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5651 offset_ptr->constant = -sp_offset +
5652 #ifdef ARGS_GROW_DOWNWARD
5653 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5655 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5657 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5658 alignment_pad->constant = offset_ptr->constant - save_constant;
5664 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
5666 if (passed_mode != BLKmode)
5668 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5669 offset_ptr->constant
5670 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5671 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5672 - GET_MODE_SIZE (passed_mode));
5676 if (TREE_CODE (sizetree) != INTEGER_CST
5677 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5679 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5680 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5682 ADD_PARM_SIZE (*offset_ptr, s2);
5683 SUB_PARM_SIZE (*offset_ptr, sizetree);
5688 /* Walk the tree of blocks describing the binding levels within a function
5689 and warn about uninitialized variables.
5690 This is done after calling flow_analysis and before global_alloc
5691 clobbers the pseudo-regs to hard regs. */
5694 uninitialized_vars_warning (tree block)
5697 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5699 if (warn_uninitialized
5700 && TREE_CODE (decl) == VAR_DECL
5701 /* These warnings are unreliable for and aggregates
5702 because assigning the fields one by one can fail to convince
5703 flow.c that the entire aggregate was initialized.
5704 Unions are troublesome because members may be shorter. */
5705 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
5706 && DECL_RTL_SET_P (decl)
5707 && GET_CODE (DECL_RTL (decl)) == REG
5708 /* Global optimizations can make it difficult to determine if a
5709 particular variable has been initialized. However, a VAR_DECL
5710 with a nonzero DECL_INITIAL had an initializer, so do not
5711 claim it is potentially uninitialized.
5713 When the DECL_INITIAL is NULL call the language hook to tell us
5714 if we want to warn. */
5715 && (DECL_INITIAL (decl) == NULL_TREE || lang_hooks.decl_uninit (decl))
5716 && regno_uninitialized (REGNO (DECL_RTL (decl))))
5717 warning ("%J'%D' might be used uninitialized in this function",
5720 && TREE_CODE (decl) == VAR_DECL
5721 && DECL_RTL_SET_P (decl)
5722 && GET_CODE (DECL_RTL (decl)) == REG
5723 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5724 warning ("%Jvariable '%D' might be clobbered by `longjmp' or `vfork'",
5727 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5728 uninitialized_vars_warning (sub);
5731 /* Do the appropriate part of uninitialized_vars_warning
5732 but for arguments instead of local variables. */
5735 setjmp_args_warning (void)
5738 for (decl = DECL_ARGUMENTS (current_function_decl);
5739 decl; decl = TREE_CHAIN (decl))
5740 if (DECL_RTL (decl) != 0
5741 && GET_CODE (DECL_RTL (decl)) == REG
5742 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5743 warning ("%Jargument '%D' might be clobbered by `longjmp' or `vfork'",
5747 /* If this function call setjmp, put all vars into the stack
5748 unless they were declared `register'. */
5751 setjmp_protect (tree block)
5754 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5755 if ((TREE_CODE (decl) == VAR_DECL
5756 || TREE_CODE (decl) == PARM_DECL)
5757 && DECL_RTL (decl) != 0
5758 && (GET_CODE (DECL_RTL (decl)) == REG
5759 || (GET_CODE (DECL_RTL (decl)) == MEM
5760 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5761 /* If this variable came from an inline function, it must be
5762 that its life doesn't overlap the setjmp. If there was a
5763 setjmp in the function, it would already be in memory. We
5764 must exclude such variable because their DECL_RTL might be
5765 set to strange things such as virtual_stack_vars_rtx. */
5766 && ! DECL_FROM_INLINE (decl)
5768 #ifdef NON_SAVING_SETJMP
5769 /* If longjmp doesn't restore the registers,
5770 don't put anything in them. */
5774 ! DECL_REGISTER (decl)))
5775 put_var_into_stack (decl, /*rescan=*/true);
5776 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5777 setjmp_protect (sub);
5780 /* Like the previous function, but for args instead of local variables. */
5783 setjmp_protect_args (void)
5786 for (decl = DECL_ARGUMENTS (current_function_decl);
5787 decl; decl = TREE_CHAIN (decl))
5788 if ((TREE_CODE (decl) == VAR_DECL
5789 || TREE_CODE (decl) == PARM_DECL)
5790 && DECL_RTL (decl) != 0
5791 && (GET_CODE (DECL_RTL (decl)) == REG
5792 || (GET_CODE (DECL_RTL (decl)) == MEM
5793 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5795 /* If longjmp doesn't restore the registers,
5796 don't put anything in them. */
5797 #ifdef NON_SAVING_SETJMP
5801 ! DECL_REGISTER (decl)))
5802 put_var_into_stack (decl, /*rescan=*/true);
5805 /* Return the context-pointer register corresponding to DECL,
5806 or 0 if it does not need one. */
5809 lookup_static_chain (tree decl)
5811 tree context = decl_function_context (decl);
5815 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_NO_STATIC_CHAIN (decl)))
5818 /* We treat inline_function_decl as an alias for the current function
5819 because that is the inline function whose vars, types, etc.
5820 are being merged into the current function.
5821 See expand_inline_function. */
5822 if (context == current_function_decl || context == inline_function_decl)
5823 return virtual_stack_vars_rtx;
5825 for (link = context_display; link; link = TREE_CHAIN (link))
5826 if (TREE_PURPOSE (link) == context)
5827 return RTL_EXPR_RTL (TREE_VALUE (link));
5832 /* Convert a stack slot address ADDR for variable VAR
5833 (from a containing function)
5834 into an address valid in this function (using a static chain). */
5837 fix_lexical_addr (rtx addr, tree var)
5840 HOST_WIDE_INT displacement;
5841 tree context = decl_function_context (var);
5842 struct function *fp;
5845 /* If this is the present function, we need not do anything. */
5846 if (context == current_function_decl || context == inline_function_decl)
5849 fp = find_function_data (context);
5851 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5852 addr = XEXP (XEXP (addr, 0), 0);
5854 /* Decode given address as base reg plus displacement. */
5855 if (GET_CODE (addr) == REG)
5856 basereg = addr, displacement = 0;
5857 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5858 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5862 /* We accept vars reached via the containing function's
5863 incoming arg pointer and via its stack variables pointer. */
5864 if (basereg == fp->internal_arg_pointer)
5866 /* If reached via arg pointer, get the arg pointer value
5867 out of that function's stack frame.
5869 There are two cases: If a separate ap is needed, allocate a
5870 slot in the outer function for it and dereference it that way.
5871 This is correct even if the real ap is actually a pseudo.
5872 Otherwise, just adjust the offset from the frame pointer to
5875 #ifdef NEED_SEPARATE_AP
5878 addr = get_arg_pointer_save_area (fp);
5879 addr = fix_lexical_addr (XEXP (addr, 0), var);
5880 addr = memory_address (Pmode, addr);
5882 base = gen_rtx_MEM (Pmode, addr);
5883 set_mem_alias_set (base, get_frame_alias_set ());
5884 base = copy_to_reg (base);
5886 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
5887 base = lookup_static_chain (var);
5891 else if (basereg == virtual_stack_vars_rtx)
5893 /* This is the same code as lookup_static_chain, duplicated here to
5894 avoid an extra call to decl_function_context. */
5897 for (link = context_display; link; link = TREE_CHAIN (link))
5898 if (TREE_PURPOSE (link) == context)
5900 base = RTL_EXPR_RTL (TREE_VALUE (link));
5908 /* Use same offset, relative to appropriate static chain or argument
5910 return plus_constant (base, displacement);
5913 /* Return the address of the trampoline for entering nested fn FUNCTION.
5914 If necessary, allocate a trampoline (in the stack frame)
5915 and emit rtl to initialize its contents (at entry to this function). */
5918 trampoline_address (tree function)
5923 struct function *fp;
5926 /* Find an existing trampoline and return it. */
5927 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5928 if (TREE_PURPOSE (link) == function)
5930 adjust_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
5932 for (fp = outer_function_chain; fp; fp = fp->outer)
5933 for (link = fp->x_trampoline_list; link; link = TREE_CHAIN (link))
5934 if (TREE_PURPOSE (link) == function)
5936 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
5938 return adjust_trampoline_addr (tramp);
5941 /* None exists; we must make one. */
5943 /* Find the `struct function' for the function containing FUNCTION. */
5945 fn_context = decl_function_context (function);
5946 if (fn_context != current_function_decl
5947 && fn_context != inline_function_decl)
5948 fp = find_function_data (fn_context);
5950 /* Allocate run-time space for this trampoline. */
5951 /* If rounding needed, allocate extra space
5952 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
5953 #define TRAMPOLINE_REAL_SIZE \
5954 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
5955 tramp = assign_stack_local_1 (BLKmode, TRAMPOLINE_REAL_SIZE, 0,
5957 /* Record the trampoline for reuse and note it for later initialization
5958 by expand_function_end. */
5961 rtlexp = make_node (RTL_EXPR);
5962 RTL_EXPR_RTL (rtlexp) = tramp;
5963 fp->x_trampoline_list = tree_cons (function, rtlexp,
5964 fp->x_trampoline_list);
5968 /* Make the RTL_EXPR node temporary, not momentary, so that the
5969 trampoline_list doesn't become garbage. */
5970 rtlexp = make_node (RTL_EXPR);
5972 RTL_EXPR_RTL (rtlexp) = tramp;
5973 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
5976 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
5977 return adjust_trampoline_addr (tramp);
5980 /* Given a trampoline address,
5981 round it to multiple of TRAMPOLINE_ALIGNMENT. */
5984 round_trampoline_addr (rtx tramp)
5986 /* Round address up to desired boundary. */
5987 rtx temp = gen_reg_rtx (Pmode);
5988 rtx addend = GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1);
5989 rtx mask = GEN_INT (-TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT);
5991 temp = expand_simple_binop (Pmode, PLUS, tramp, addend,
5992 temp, 0, OPTAB_LIB_WIDEN);
5993 tramp = expand_simple_binop (Pmode, AND, temp, mask,
5994 temp, 0, OPTAB_LIB_WIDEN);
5999 /* Given a trampoline address, round it then apply any
6000 platform-specific adjustments so that the result can be used for a
6004 adjust_trampoline_addr (rtx tramp)
6006 tramp = round_trampoline_addr (tramp);
6007 #ifdef TRAMPOLINE_ADJUST_ADDRESS
6008 TRAMPOLINE_ADJUST_ADDRESS (tramp);
6013 /* Put all this function's BLOCK nodes including those that are chained
6014 onto the first block into a vector, and return it.
6015 Also store in each NOTE for the beginning or end of a block
6016 the index of that block in the vector.
6017 The arguments are BLOCK, the chain of top-level blocks of the function,
6018 and INSNS, the insn chain of the function. */
6021 identify_blocks (void)
6024 tree *block_vector, *last_block_vector;
6026 tree block = DECL_INITIAL (current_function_decl);
6031 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
6032 depth-first order. */
6033 block_vector = get_block_vector (block, &n_blocks);
6034 block_stack = xmalloc (n_blocks * sizeof (tree));
6036 last_block_vector = identify_blocks_1 (get_insns (),
6038 block_vector + n_blocks,
6041 /* If we didn't use all of the subblocks, we've misplaced block notes. */
6042 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
6043 if (0 && last_block_vector != block_vector + n_blocks)
6046 free (block_vector);
6050 /* Subroutine of identify_blocks. Do the block substitution on the
6051 insn chain beginning with INSNS. Recurse for CALL_PLACEHOLDER chains.
6053 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
6054 BLOCK_VECTOR is incremented for each block seen. */
6057 identify_blocks_1 (rtx insns, tree *block_vector, tree *end_block_vector,
6058 tree *orig_block_stack)
6061 tree *block_stack = orig_block_stack;
6063 for (insn = insns; insn; insn = NEXT_INSN (insn))
6065 if (GET_CODE (insn) == NOTE)
6067 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
6071 /* If there are more block notes than BLOCKs, something
6073 if (block_vector == end_block_vector)
6076 b = *block_vector++;
6077 NOTE_BLOCK (insn) = b;
6080 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6082 /* If there are more NOTE_INSN_BLOCK_ENDs than
6083 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
6084 if (block_stack == orig_block_stack)
6087 NOTE_BLOCK (insn) = *--block_stack;
6090 else if (GET_CODE (insn) == CALL_INSN
6091 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
6093 rtx cp = PATTERN (insn);
6095 block_vector = identify_blocks_1 (XEXP (cp, 0), block_vector,
6096 end_block_vector, block_stack);
6098 block_vector = identify_blocks_1 (XEXP (cp, 1), block_vector,
6099 end_block_vector, block_stack);
6101 block_vector = identify_blocks_1 (XEXP (cp, 2), block_vector,
6102 end_block_vector, block_stack);
6106 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
6107 something is badly wrong. */
6108 if (block_stack != orig_block_stack)
6111 return block_vector;
6114 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
6115 and create duplicate blocks. */
6116 /* ??? Need an option to either create block fragments or to create
6117 abstract origin duplicates of a source block. It really depends
6118 on what optimization has been performed. */
6121 reorder_blocks (void)
6123 tree block = DECL_INITIAL (current_function_decl);
6124 varray_type block_stack;
6126 if (block == NULL_TREE)
6129 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
6131 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
6132 reorder_blocks_0 (block);
6134 /* Prune the old trees away, so that they don't get in the way. */
6135 BLOCK_SUBBLOCKS (block) = NULL_TREE;
6136 BLOCK_CHAIN (block) = NULL_TREE;
6138 /* Recreate the block tree from the note nesting. */
6139 reorder_blocks_1 (get_insns (), block, &block_stack);
6140 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
6142 /* Remove deleted blocks from the block fragment chains. */
6143 reorder_fix_fragments (block);
6146 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
6149 reorder_blocks_0 (tree block)
6153 TREE_ASM_WRITTEN (block) = 0;
6154 reorder_blocks_0 (BLOCK_SUBBLOCKS (block));
6155 block = BLOCK_CHAIN (block);
6160 reorder_blocks_1 (rtx insns, tree current_block, varray_type *p_block_stack)
6164 for (insn = insns; insn; insn = NEXT_INSN (insn))
6166 if (GET_CODE (insn) == NOTE)
6168 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
6170 tree block = NOTE_BLOCK (insn);
6172 /* If we have seen this block before, that means it now
6173 spans multiple address regions. Create a new fragment. */
6174 if (TREE_ASM_WRITTEN (block))
6176 tree new_block = copy_node (block);
6179 origin = (BLOCK_FRAGMENT_ORIGIN (block)
6180 ? BLOCK_FRAGMENT_ORIGIN (block)
6182 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
6183 BLOCK_FRAGMENT_CHAIN (new_block)
6184 = BLOCK_FRAGMENT_CHAIN (origin);
6185 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
6187 NOTE_BLOCK (insn) = new_block;
6191 BLOCK_SUBBLOCKS (block) = 0;
6192 TREE_ASM_WRITTEN (block) = 1;
6193 /* When there's only one block for the entire function,
6194 current_block == block and we mustn't do this, it
6195 will cause infinite recursion. */
6196 if (block != current_block)
6198 BLOCK_SUPERCONTEXT (block) = current_block;
6199 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
6200 BLOCK_SUBBLOCKS (current_block) = block;
6201 current_block = block;
6203 VARRAY_PUSH_TREE (*p_block_stack, block);
6205 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6207 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
6208 VARRAY_POP (*p_block_stack);
6209 BLOCK_SUBBLOCKS (current_block)
6210 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
6211 current_block = BLOCK_SUPERCONTEXT (current_block);
6214 else if (GET_CODE (insn) == CALL_INSN
6215 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
6217 rtx cp = PATTERN (insn);
6218 reorder_blocks_1 (XEXP (cp, 0), current_block, p_block_stack);
6220 reorder_blocks_1 (XEXP (cp, 1), current_block, p_block_stack);
6222 reorder_blocks_1 (XEXP (cp, 2), current_block, p_block_stack);
6227 /* Rationalize BLOCK_FRAGMENT_ORIGIN. If an origin block no longer
6228 appears in the block tree, select one of the fragments to become
6229 the new origin block. */
6232 reorder_fix_fragments (tree block)
6236 tree dup_origin = BLOCK_FRAGMENT_ORIGIN (block);
6237 tree new_origin = NULL_TREE;
6241 if (! TREE_ASM_WRITTEN (dup_origin))
6243 new_origin = BLOCK_FRAGMENT_CHAIN (dup_origin);
6245 /* Find the first of the remaining fragments. There must
6246 be at least one -- the current block. */
6247 while (! TREE_ASM_WRITTEN (new_origin))
6248 new_origin = BLOCK_FRAGMENT_CHAIN (new_origin);
6249 BLOCK_FRAGMENT_ORIGIN (new_origin) = NULL_TREE;
6252 else if (! dup_origin)
6255 /* Re-root the rest of the fragments to the new origin. In the
6256 case that DUP_ORIGIN was null, that means BLOCK was the origin
6257 of a chain of fragments and we want to remove those fragments
6258 that didn't make it to the output. */
6261 tree *pp = &BLOCK_FRAGMENT_CHAIN (new_origin);
6266 if (TREE_ASM_WRITTEN (chain))
6268 BLOCK_FRAGMENT_ORIGIN (chain) = new_origin;
6270 pp = &BLOCK_FRAGMENT_CHAIN (chain);
6272 chain = BLOCK_FRAGMENT_CHAIN (chain);
6277 reorder_fix_fragments (BLOCK_SUBBLOCKS (block));
6278 block = BLOCK_CHAIN (block);
6282 /* Reverse the order of elements in the chain T of blocks,
6283 and return the new head of the chain (old last element). */
6286 blocks_nreverse (tree t)
6288 tree prev = 0, decl, next;
6289 for (decl = t; decl; decl = next)
6291 next = BLOCK_CHAIN (decl);
6292 BLOCK_CHAIN (decl) = prev;
6298 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
6299 non-NULL, list them all into VECTOR, in a depth-first preorder
6300 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
6304 all_blocks (tree block, tree *vector)
6310 TREE_ASM_WRITTEN (block) = 0;
6312 /* Record this block. */
6314 vector[n_blocks] = block;
6318 /* Record the subblocks, and their subblocks... */
6319 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
6320 vector ? vector + n_blocks : 0);
6321 block = BLOCK_CHAIN (block);
6327 /* Return a vector containing all the blocks rooted at BLOCK. The
6328 number of elements in the vector is stored in N_BLOCKS_P. The
6329 vector is dynamically allocated; it is the caller's responsibility
6330 to call `free' on the pointer returned. */
6333 get_block_vector (tree block, int *n_blocks_p)
6337 *n_blocks_p = all_blocks (block, NULL);
6338 block_vector = xmalloc (*n_blocks_p * sizeof (tree));
6339 all_blocks (block, block_vector);
6341 return block_vector;
6344 static GTY(()) int next_block_index = 2;
6346 /* Set BLOCK_NUMBER for all the blocks in FN. */
6349 number_blocks (tree fn)
6355 /* For SDB and XCOFF debugging output, we start numbering the blocks
6356 from 1 within each function, rather than keeping a running
6358 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
6359 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
6360 next_block_index = 1;
6363 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
6365 /* The top-level BLOCK isn't numbered at all. */
6366 for (i = 1; i < n_blocks; ++i)
6367 /* We number the blocks from two. */
6368 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
6370 free (block_vector);
6375 /* If VAR is present in a subblock of BLOCK, return the subblock. */
6378 debug_find_var_in_block_tree (tree var, tree block)
6382 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
6386 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
6388 tree ret = debug_find_var_in_block_tree (var, t);
6396 /* Allocate a function structure for FNDECL and set its contents
6400 allocate_struct_function (tree fndecl)
6404 cfun = ggc_alloc_cleared (sizeof (struct function));
6406 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
6408 cfun->stack_alignment_needed = STACK_BOUNDARY;
6409 cfun->preferred_stack_boundary = STACK_BOUNDARY;
6411 current_function_funcdef_no = funcdef_no++;
6413 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
6415 init_stmt_for_function ();
6416 init_eh_for_function ();
6418 (*lang_hooks.function.init) (cfun);
6419 if (init_machine_status)
6420 cfun->machine = (*init_machine_status) ();
6425 DECL_SAVED_INSNS (fndecl) = cfun;
6426 cfun->decl = fndecl;
6428 result = DECL_RESULT (fndecl);
6429 if (aggregate_value_p (result, fndecl))
6431 #ifdef PCC_STATIC_STRUCT_RETURN
6432 current_function_returns_pcc_struct = 1;
6434 current_function_returns_struct = 1;
6437 current_function_returns_pointer = POINTER_TYPE_P (TREE_TYPE (result));
6439 current_function_needs_context
6440 = (decl_function_context (current_function_decl) != 0
6441 && ! DECL_NO_STATIC_CHAIN (current_function_decl));
6444 /* Reset cfun, and other non-struct-function variables to defaults as
6445 appropriate for emitting rtl at the start of a function. */
6448 prepare_function_start (tree fndecl)
6450 if (fndecl && DECL_SAVED_INSNS (fndecl))
6451 cfun = DECL_SAVED_INSNS (fndecl);
6453 allocate_struct_function (fndecl);
6455 init_varasm_status (cfun);
6458 cse_not_expected = ! optimize;
6460 /* Caller save not needed yet. */
6461 caller_save_needed = 0;
6463 /* We haven't done register allocation yet. */
6466 /* Indicate that we need to distinguish between the return value of the
6467 present function and the return value of a function being called. */
6468 rtx_equal_function_value_matters = 1;
6470 /* Indicate that we have not instantiated virtual registers yet. */
6471 virtuals_instantiated = 0;
6473 /* Indicate that we want CONCATs now. */
6474 generating_concat_p = 1;
6476 /* Indicate we have no need of a frame pointer yet. */
6477 frame_pointer_needed = 0;
6480 /* Initialize the rtl expansion mechanism so that we can do simple things
6481 like generate sequences. This is used to provide a context during global
6482 initialization of some passes. */
6484 init_dummy_function_start (void)
6486 prepare_function_start (NULL);
6489 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
6490 and initialize static variables for generating RTL for the statements
6494 init_function_start (tree subr)
6496 prepare_function_start (subr);
6498 /* Within function body, compute a type's size as soon it is laid out. */
6499 immediate_size_expand++;
6501 /* Prevent ever trying to delete the first instruction of a
6502 function. Also tell final how to output a linenum before the
6503 function prologue. Note linenums could be missing, e.g. when
6504 compiling a Java .class file. */
6505 if (DECL_SOURCE_LINE (subr))
6506 emit_line_note (DECL_SOURCE_LOCATION (subr));
6508 /* Make sure first insn is a note even if we don't want linenums.
6509 This makes sure the first insn will never be deleted.
6510 Also, final expects a note to appear there. */
6511 emit_note (NOTE_INSN_DELETED);
6513 /* Warn if this value is an aggregate type,
6514 regardless of which calling convention we are using for it. */
6515 if (warn_aggregate_return
6516 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
6517 warning ("function returns an aggregate");
6520 /* Make sure all values used by the optimization passes have sane
6523 init_function_for_compilation (void)
6527 /* No prologue/epilogue insns yet. */
6528 VARRAY_GROW (prologue, 0);
6529 VARRAY_GROW (epilogue, 0);
6530 VARRAY_GROW (sibcall_epilogue, 0);
6533 /* Expand a call to __main at the beginning of a possible main function. */
6535 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6536 #undef HAS_INIT_SECTION
6537 #define HAS_INIT_SECTION
6541 expand_main_function (void)
6543 #ifdef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
6544 if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN)
6546 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
6550 /* Forcibly align the stack. */
6551 #ifdef STACK_GROWS_DOWNWARD
6552 tmp = expand_simple_binop (Pmode, AND, stack_pointer_rtx, GEN_INT(-align),
6553 stack_pointer_rtx, 1, OPTAB_WIDEN);
6555 tmp = expand_simple_binop (Pmode, PLUS, stack_pointer_rtx,
6556 GEN_INT (align - 1), NULL_RTX, 1, OPTAB_WIDEN);
6557 tmp = expand_simple_binop (Pmode, AND, tmp, GEN_INT (-align),
6558 stack_pointer_rtx, 1, OPTAB_WIDEN);
6560 if (tmp != stack_pointer_rtx)
6561 emit_move_insn (stack_pointer_rtx, tmp);
6563 /* Enlist allocate_dynamic_stack_space to pick up the pieces. */
6564 tmp = force_reg (Pmode, const0_rtx);
6565 allocate_dynamic_stack_space (tmp, NULL_RTX, BIGGEST_ALIGNMENT);
6569 for (tmp = get_last_insn (); tmp; tmp = PREV_INSN (tmp))
6570 if (NOTE_P (tmp) && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_FUNCTION_BEG)
6573 emit_insn_before (seq, tmp);
6579 #ifndef HAS_INIT_SECTION
6580 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
6584 /* The PENDING_SIZES represent the sizes of variable-sized types.
6585 Create RTL for the various sizes now (using temporary variables),
6586 so that we can refer to the sizes from the RTL we are generating
6587 for the current function. The PENDING_SIZES are a TREE_LIST. The
6588 TREE_VALUE of each node is a SAVE_EXPR. */
6591 expand_pending_sizes (tree pending_sizes)
6595 /* Evaluate now the sizes of any types declared among the arguments. */
6596 for (tem = pending_sizes; tem; tem = TREE_CHAIN (tem))
6598 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
6599 /* Flush the queue in case this parameter declaration has
6605 /* Start the RTL for a new function, and set variables used for
6607 SUBR is the FUNCTION_DECL node.
6608 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6609 the function's parameters, which must be run at any return statement. */
6612 expand_function_start (tree subr, int parms_have_cleanups)
6615 rtx last_ptr = NULL_RTX;
6617 /* Make sure volatile mem refs aren't considered
6618 valid operands of arithmetic insns. */
6619 init_recog_no_volatile ();
6621 current_function_instrument_entry_exit
6622 = (flag_instrument_function_entry_exit
6623 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6625 current_function_profile
6627 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6629 current_function_limit_stack
6630 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6632 /* If function gets a static chain arg, store it in the stack frame.
6633 Do this first, so it gets the first stack slot offset. */
6634 if (current_function_needs_context)
6636 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
6638 /* Delay copying static chain if it is not a register to avoid
6639 conflicts with regs used for parameters. */
6640 if (! SMALL_REGISTER_CLASSES
6641 || GET_CODE (static_chain_incoming_rtx) == REG)
6642 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6645 /* If the parameters of this function need cleaning up, get a label
6646 for the beginning of the code which executes those cleanups. This must
6647 be done before doing anything with return_label. */
6648 if (parms_have_cleanups)
6649 cleanup_label = gen_label_rtx ();
6653 /* Make the label for return statements to jump to. Do not special
6654 case machines with special return instructions -- they will be
6655 handled later during jump, ifcvt, or epilogue creation. */
6656 return_label = gen_label_rtx ();
6658 /* Initialize rtx used to return the value. */
6659 /* Do this before assign_parms so that we copy the struct value address
6660 before any library calls that assign parms might generate. */
6662 /* Decide whether to return the value in memory or in a register. */
6663 if (aggregate_value_p (DECL_RESULT (subr), subr))
6665 /* Returning something that won't go in a register. */
6666 rtx value_address = 0;
6668 #ifdef PCC_STATIC_STRUCT_RETURN
6669 if (current_function_returns_pcc_struct)
6671 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6672 value_address = assemble_static_space (size);
6677 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 1);
6678 /* Expect to be passed the address of a place to store the value.
6679 If it is passed as an argument, assign_parms will take care of
6683 value_address = gen_reg_rtx (Pmode);
6684 emit_move_insn (value_address, sv);
6689 rtx x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6690 set_mem_attributes (x, DECL_RESULT (subr), 1);
6691 SET_DECL_RTL (DECL_RESULT (subr), x);
6694 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6695 /* If return mode is void, this decl rtl should not be used. */
6696 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
6699 /* Compute the return values into a pseudo reg, which we will copy
6700 into the true return register after the cleanups are done. */
6702 /* In order to figure out what mode to use for the pseudo, we
6703 figure out what the mode of the eventual return register will
6704 actually be, and use that. */
6706 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)),
6709 /* Structures that are returned in registers are not aggregate_value_p,
6710 so we may see a PARALLEL or a REG. */
6711 if (REG_P (hard_reg))
6712 SET_DECL_RTL (DECL_RESULT (subr), gen_reg_rtx (GET_MODE (hard_reg)));
6713 else if (GET_CODE (hard_reg) == PARALLEL)
6714 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
6718 /* Set DECL_REGISTER flag so that expand_function_end will copy the
6719 result to the real return register(s). */
6720 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6723 /* Initialize rtx for parameters and local variables.
6724 In some cases this requires emitting insns. */
6726 assign_parms (subr);
6728 /* Copy the static chain now if it wasn't a register. The delay is to
6729 avoid conflicts with the parameter passing registers. */
6731 if (SMALL_REGISTER_CLASSES && current_function_needs_context)
6732 if (GET_CODE (static_chain_incoming_rtx) != REG)
6733 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6735 /* The following was moved from init_function_start.
6736 The move is supposed to make sdb output more accurate. */
6737 /* Indicate the beginning of the function body,
6738 as opposed to parm setup. */
6739 emit_note (NOTE_INSN_FUNCTION_BEG);
6741 if (GET_CODE (get_last_insn ()) != NOTE)
6742 emit_note (NOTE_INSN_DELETED);
6743 parm_birth_insn = get_last_insn ();
6745 context_display = 0;
6746 if (current_function_needs_context)
6748 /* Fetch static chain values for containing functions. */
6749 tem = decl_function_context (current_function_decl);
6750 /* Copy the static chain pointer into a pseudo. If we have
6751 small register classes, copy the value from memory if
6752 static_chain_incoming_rtx is a REG. */
6755 /* If the static chain originally came in a register, put it back
6756 there, then move it out in the next insn. The reason for
6757 this peculiar code is to satisfy function integration. */
6758 if (SMALL_REGISTER_CLASSES
6759 && GET_CODE (static_chain_incoming_rtx) == REG)
6760 emit_move_insn (static_chain_incoming_rtx, last_ptr);
6761 last_ptr = copy_to_reg (static_chain_incoming_rtx);
6766 tree rtlexp = make_node (RTL_EXPR);
6768 RTL_EXPR_RTL (rtlexp) = last_ptr;
6769 context_display = tree_cons (tem, rtlexp, context_display);
6770 tem = decl_function_context (tem);
6773 /* Chain through stack frames, assuming pointer to next lexical frame
6774 is found at the place we always store it. */
6775 #ifdef FRAME_GROWS_DOWNWARD
6776 last_ptr = plus_constant (last_ptr,
6777 -(HOST_WIDE_INT) GET_MODE_SIZE (Pmode));
6779 last_ptr = gen_rtx_MEM (Pmode, memory_address (Pmode, last_ptr));
6780 set_mem_alias_set (last_ptr, get_frame_alias_set ());
6781 last_ptr = copy_to_reg (last_ptr);
6783 /* If we are not optimizing, ensure that we know that this
6784 piece of context is live over the entire function. */
6786 save_expr_regs = gen_rtx_EXPR_LIST (VOIDmode, last_ptr,
6791 if (current_function_instrument_entry_exit)
6793 rtx fun = DECL_RTL (current_function_decl);
6794 if (GET_CODE (fun) == MEM)
6795 fun = XEXP (fun, 0);
6798 emit_library_call (profile_function_entry_libfunc, LCT_NORMAL, VOIDmode,
6800 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6802 hard_frame_pointer_rtx),
6806 if (current_function_profile)
6809 PROFILE_HOOK (current_function_funcdef_no);
6813 /* After the display initializations is where the tail-recursion label
6814 should go, if we end up needing one. Ensure we have a NOTE here
6815 since some things (like trampolines) get placed before this. */
6816 tail_recursion_reentry = emit_note (NOTE_INSN_DELETED);
6818 /* Evaluate now the sizes of any types declared among the arguments. */
6819 expand_pending_sizes (nreverse (get_pending_sizes ()));
6821 /* Make sure there is a line number after the function entry setup code. */
6822 force_next_line_note ();
6825 /* Undo the effects of init_dummy_function_start. */
6827 expand_dummy_function_end (void)
6829 /* End any sequences that failed to be closed due to syntax errors. */
6830 while (in_sequence_p ())
6833 /* Outside function body, can't compute type's actual size
6834 until next function's body starts. */
6836 free_after_parsing (cfun);
6837 free_after_compilation (cfun);
6841 /* Call DOIT for each hard register used as a return value from
6842 the current function. */
6845 diddle_return_value (void (*doit) (rtx, void *), void *arg)
6847 rtx outgoing = current_function_return_rtx;
6852 if (GET_CODE (outgoing) == REG)
6853 (*doit) (outgoing, arg);
6854 else if (GET_CODE (outgoing) == PARALLEL)
6858 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6860 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6862 if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
6869 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6871 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6875 clobber_return_register (void)
6877 diddle_return_value (do_clobber_return_reg, NULL);
6879 /* In case we do use pseudo to return value, clobber it too. */
6880 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6882 tree decl_result = DECL_RESULT (current_function_decl);
6883 rtx decl_rtl = DECL_RTL (decl_result);
6884 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
6886 do_clobber_return_reg (decl_rtl, NULL);
6892 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6894 emit_insn (gen_rtx_USE (VOIDmode, reg));
6898 use_return_register (void)
6900 diddle_return_value (do_use_return_reg, NULL);
6903 /* Possibly warn about unused parameters. */
6905 do_warn_unused_parameter (tree fn)
6909 for (decl = DECL_ARGUMENTS (fn);
6910 decl; decl = TREE_CHAIN (decl))
6911 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6912 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl))
6913 warning ("%Junused parameter '%D'", decl, decl);
6916 static GTY(()) rtx initial_trampoline;
6918 /* Generate RTL for the end of the current function. */
6921 expand_function_end (void)
6926 finish_expr_for_function ();
6928 /* If arg_pointer_save_area was referenced only from a nested
6929 function, we will not have initialized it yet. Do that now. */
6930 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
6931 get_arg_pointer_save_area (cfun);
6933 #ifdef NON_SAVING_SETJMP
6934 /* Don't put any variables in registers if we call setjmp
6935 on a machine that fails to restore the registers. */
6936 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6938 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6939 setjmp_protect (DECL_INITIAL (current_function_decl));
6941 setjmp_protect_args ();
6945 /* Initialize any trampolines required by this function. */
6946 for (link = trampoline_list; link; link = TREE_CHAIN (link))
6948 tree function = TREE_PURPOSE (link);
6949 rtx context ATTRIBUTE_UNUSED = lookup_static_chain (function);
6950 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
6951 #ifdef TRAMPOLINE_TEMPLATE
6956 #ifdef TRAMPOLINE_TEMPLATE
6957 /* First make sure this compilation has a template for
6958 initializing trampolines. */
6959 if (initial_trampoline == 0)
6962 = gen_rtx_MEM (BLKmode, assemble_trampoline_template ());
6963 set_mem_align (initial_trampoline, TRAMPOLINE_ALIGNMENT);
6967 /* Generate insns to initialize the trampoline. */
6969 tramp = round_trampoline_addr (XEXP (tramp, 0));
6970 #ifdef TRAMPOLINE_TEMPLATE
6971 blktramp = replace_equiv_address (initial_trampoline, tramp);
6972 emit_block_move (blktramp, initial_trampoline,
6973 GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);
6975 trampolines_created = 1;
6976 INITIALIZE_TRAMPOLINE (tramp, XEXP (DECL_RTL (function), 0), context);
6980 /* Put those insns at entry to the containing function (this one). */
6981 emit_insn_before (seq, tail_recursion_reentry);
6984 /* If we are doing stack checking and this function makes calls,
6985 do a stack probe at the start of the function to ensure we have enough
6986 space for another stack frame. */
6987 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
6991 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6992 if (GET_CODE (insn) == CALL_INSN)
6995 probe_stack_range (STACK_CHECK_PROTECT,
6996 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
6999 emit_insn_before (seq, tail_recursion_reentry);
7004 /* Possibly warn about unused parameters.
7005 When frontend does unit-at-a-time, the warning is already
7006 issued at finalization time. */
7007 if (warn_unused_parameter
7008 && !lang_hooks.callgraph.expand_function)
7009 do_warn_unused_parameter (current_function_decl);
7011 /* Delete handlers for nonlocal gotos if nothing uses them. */
7012 if (nonlocal_goto_handler_slots != 0
7013 && ! current_function_has_nonlocal_label)
7016 /* End any sequences that failed to be closed due to syntax errors. */
7017 while (in_sequence_p ())
7020 /* Outside function body, can't compute type's actual size
7021 until next function's body starts. */
7022 immediate_size_expand--;
7024 clear_pending_stack_adjust ();
7025 do_pending_stack_adjust ();
7027 /* ??? This is a kludge. We want to ensure that instructions that
7028 may trap are not moved into the epilogue by scheduling, because
7029 we don't always emit unwind information for the epilogue.
7030 However, not all machine descriptions define a blockage insn, so
7031 emit an ASM_INPUT to act as one. */
7032 if (flag_non_call_exceptions)
7033 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
7035 /* Mark the end of the function body.
7036 If control reaches this insn, the function can drop through
7037 without returning a value. */
7038 emit_note (NOTE_INSN_FUNCTION_END);
7040 /* Must mark the last line number note in the function, so that the test
7041 coverage code can avoid counting the last line twice. This just tells
7042 the code to ignore the immediately following line note, since there
7043 already exists a copy of this note somewhere above. This line number
7044 note is still needed for debugging though, so we can't delete it. */
7045 if (flag_test_coverage)
7046 emit_note (NOTE_INSN_REPEATED_LINE_NUMBER);
7048 /* Output a linenumber for the end of the function.
7049 SDB depends on this. */
7050 force_next_line_note ();
7051 emit_line_note (input_location);
7053 /* Before the return label (if any), clobber the return
7054 registers so that they are not propagated live to the rest of
7055 the function. This can only happen with functions that drop
7056 through; if there had been a return statement, there would
7057 have either been a return rtx, or a jump to the return label.
7059 We delay actual code generation after the current_function_value_rtx
7061 clobber_after = get_last_insn ();
7063 /* Output the label for the actual return from the function,
7064 if one is expected. This happens either because a function epilogue
7065 is used instead of a return instruction, or because a return was done
7066 with a goto in order to run local cleanups, or because of pcc-style
7067 structure returning. */
7069 emit_label (return_label);
7071 if (current_function_instrument_entry_exit)
7073 rtx fun = DECL_RTL (current_function_decl);
7074 if (GET_CODE (fun) == MEM)
7075 fun = XEXP (fun, 0);
7078 emit_library_call (profile_function_exit_libfunc, LCT_NORMAL, VOIDmode,
7080 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
7082 hard_frame_pointer_rtx),
7086 /* Let except.c know where it should emit the call to unregister
7087 the function context for sjlj exceptions. */
7088 if (flag_exceptions && USING_SJLJ_EXCEPTIONS)
7089 sjlj_emit_function_exit_after (get_last_insn ());
7091 /* If we had calls to alloca, and this machine needs
7092 an accurate stack pointer to exit the function,
7093 insert some code to save and restore the stack pointer. */
7094 if (! EXIT_IGNORE_STACK
7095 && current_function_calls_alloca)
7099 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
7100 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
7103 /* If scalar return value was computed in a pseudo-reg, or was a named
7104 return value that got dumped to the stack, copy that to the hard
7106 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
7108 tree decl_result = DECL_RESULT (current_function_decl);
7109 rtx decl_rtl = DECL_RTL (decl_result);
7111 if (REG_P (decl_rtl)
7112 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
7113 : DECL_REGISTER (decl_result))
7115 rtx real_decl_rtl = current_function_return_rtx;
7117 /* This should be set in assign_parms. */
7118 if (! REG_FUNCTION_VALUE_P (real_decl_rtl))
7121 /* If this is a BLKmode structure being returned in registers,
7122 then use the mode computed in expand_return. Note that if
7123 decl_rtl is memory, then its mode may have been changed,
7124 but that current_function_return_rtx has not. */
7125 if (GET_MODE (real_decl_rtl) == BLKmode)
7126 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
7128 /* If a named return value dumped decl_return to memory, then
7129 we may need to re-do the PROMOTE_MODE signed/unsigned
7131 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
7133 int unsignedp = TREE_UNSIGNED (TREE_TYPE (decl_result));
7135 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
7136 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
7139 convert_move (real_decl_rtl, decl_rtl, unsignedp);
7141 else if (GET_CODE (real_decl_rtl) == PARALLEL)
7143 /* If expand_function_start has created a PARALLEL for decl_rtl,
7144 move the result to the real return registers. Otherwise, do
7145 a group load from decl_rtl for a named return. */
7146 if (GET_CODE (decl_rtl) == PARALLEL)
7147 emit_group_move (real_decl_rtl, decl_rtl);
7149 emit_group_load (real_decl_rtl, decl_rtl,
7150 TREE_TYPE (decl_result),
7151 int_size_in_bytes (TREE_TYPE (decl_result)));
7154 emit_move_insn (real_decl_rtl, decl_rtl);
7158 /* If returning a structure, arrange to return the address of the value
7159 in a place where debuggers expect to find it.
7161 If returning a structure PCC style,
7162 the caller also depends on this value.
7163 And current_function_returns_pcc_struct is not necessarily set. */
7164 if (current_function_returns_struct
7165 || current_function_returns_pcc_struct)
7168 = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
7169 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
7170 #ifdef FUNCTION_OUTGOING_VALUE
7172 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
7173 current_function_decl);
7176 = FUNCTION_VALUE (build_pointer_type (type), current_function_decl);
7179 /* Mark this as a function return value so integrate will delete the
7180 assignment and USE below when inlining this function. */
7181 REG_FUNCTION_VALUE_P (outgoing) = 1;
7183 /* The address may be ptr_mode and OUTGOING may be Pmode. */
7184 value_address = convert_memory_address (GET_MODE (outgoing),
7187 emit_move_insn (outgoing, value_address);
7189 /* Show return register used to hold result (in this case the address
7191 current_function_return_rtx = outgoing;
7194 /* If this is an implementation of throw, do what's necessary to
7195 communicate between __builtin_eh_return and the epilogue. */
7196 expand_eh_return ();
7198 /* Emit the actual code to clobber return register. */
7203 clobber_return_register ();
7207 after = emit_insn_after (seq, clobber_after);
7209 if (clobber_after != after)
7210 cfun->x_clobber_return_insn = after;
7213 /* Output the label for the naked return from the function, if one is
7214 expected. This is currently used only by __builtin_return. */
7215 if (naked_return_label)
7216 emit_label (naked_return_label);
7218 /* ??? This should no longer be necessary since stupid is no longer with
7219 us, but there are some parts of the compiler (eg reload_combine, and
7220 sh mach_dep_reorg) that still try and compute their own lifetime info
7221 instead of using the general framework. */
7222 use_return_register ();
7224 /* Fix up any gotos that jumped out to the outermost
7225 binding level of the function.
7226 Must follow emitting RETURN_LABEL. */
7228 /* If you have any cleanups to do at this point,
7229 and they need to create temporary variables,
7230 then you will lose. */
7231 expand_fixups (get_insns ());
7235 get_arg_pointer_save_area (struct function *f)
7237 rtx ret = f->x_arg_pointer_save_area;
7241 ret = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, f);
7242 f->x_arg_pointer_save_area = ret;
7245 if (f == cfun && ! f->arg_pointer_save_area_init)
7249 /* Save the arg pointer at the beginning of the function. The
7250 generated stack slot may not be a valid memory address, so we
7251 have to check it and fix it if necessary. */
7253 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
7257 push_topmost_sequence ();
7258 emit_insn_after (seq, get_insns ());
7259 pop_topmost_sequence ();
7265 /* Extend a vector that records the INSN_UIDs of INSNS
7266 (a list of one or more insns). */
7269 record_insns (rtx insns, varray_type *vecp)
7276 while (tmp != NULL_RTX)
7279 tmp = NEXT_INSN (tmp);
7282 i = VARRAY_SIZE (*vecp);
7283 VARRAY_GROW (*vecp, i + len);
7285 while (tmp != NULL_RTX)
7287 VARRAY_INT (*vecp, i) = INSN_UID (tmp);
7289 tmp = NEXT_INSN (tmp);
7293 /* Set the locator of the insn chain starting at INSN to LOC. */
7295 set_insn_locators (rtx insn, int loc)
7297 while (insn != NULL_RTX)
7300 INSN_LOCATOR (insn) = loc;
7301 insn = NEXT_INSN (insn);
7305 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
7306 be running after reorg, SEQUENCE rtl is possible. */
7309 contains (rtx insn, varray_type vec)
7313 if (GET_CODE (insn) == INSN
7314 && GET_CODE (PATTERN (insn)) == SEQUENCE)
7317 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
7318 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7319 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
7325 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
7326 if (INSN_UID (insn) == VARRAY_INT (vec, j))
7333 prologue_epilogue_contains (rtx insn)
7335 if (contains (insn, prologue))
7337 if (contains (insn, epilogue))
7343 sibcall_epilogue_contains (rtx insn)
7345 if (sibcall_epilogue)
7346 return contains (insn, sibcall_epilogue);
7351 /* Insert gen_return at the end of block BB. This also means updating
7352 block_for_insn appropriately. */
7355 emit_return_into_block (basic_block bb, rtx line_note)
7357 emit_jump_insn_after (gen_return (), BB_END (bb));
7359 emit_note_copy_after (line_note, PREV_INSN (BB_END (bb)));
7361 #endif /* HAVE_return */
7363 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
7365 /* These functions convert the epilogue into a variant that does not modify the
7366 stack pointer. This is used in cases where a function returns an object
7367 whose size is not known until it is computed. The called function leaves the
7368 object on the stack, leaves the stack depressed, and returns a pointer to
7371 What we need to do is track all modifications and references to the stack
7372 pointer, deleting the modifications and changing the references to point to
7373 the location the stack pointer would have pointed to had the modifications
7376 These functions need to be portable so we need to make as few assumptions
7377 about the epilogue as we can. However, the epilogue basically contains
7378 three things: instructions to reset the stack pointer, instructions to
7379 reload registers, possibly including the frame pointer, and an
7380 instruction to return to the caller.
7382 If we can't be sure of what a relevant epilogue insn is doing, we abort.
7383 We also make no attempt to validate the insns we make since if they are
7384 invalid, we probably can't do anything valid. The intent is that these
7385 routines get "smarter" as more and more machines start to use them and
7386 they try operating on different epilogues.
7388 We use the following structure to track what the part of the epilogue that
7389 we've already processed has done. We keep two copies of the SP equivalence,
7390 one for use during the insn we are processing and one for use in the next
7391 insn. The difference is because one part of a PARALLEL may adjust SP
7392 and the other may use it. */
7396 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
7397 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
7398 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
7399 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
7400 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
7401 should be set to once we no longer need
7403 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
7407 static void handle_epilogue_set (rtx, struct epi_info *);
7408 static void update_epilogue_consts (rtx, rtx, void *);
7409 static void emit_equiv_load (struct epi_info *);
7411 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
7412 no modifications to the stack pointer. Return the new list of insns. */
7415 keep_stack_depressed (rtx insns)
7418 struct epi_info info;
7421 /* If the epilogue is just a single instruction, it must be OK as is. */
7422 if (NEXT_INSN (insns) == NULL_RTX)
7425 /* Otherwise, start a sequence, initialize the information we have, and
7426 process all the insns we were given. */
7429 info.sp_equiv_reg = stack_pointer_rtx;
7431 info.equiv_reg_src = 0;
7433 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
7434 info.const_equiv[j] = 0;
7438 while (insn != NULL_RTX)
7440 next = NEXT_INSN (insn);
7449 /* If this insn references the register that SP is equivalent to and
7450 we have a pending load to that register, we must force out the load
7451 first and then indicate we no longer know what SP's equivalent is. */
7452 if (info.equiv_reg_src != 0
7453 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
7455 emit_equiv_load (&info);
7456 info.sp_equiv_reg = 0;
7459 info.new_sp_equiv_reg = info.sp_equiv_reg;
7460 info.new_sp_offset = info.sp_offset;
7462 /* If this is a (RETURN) and the return address is on the stack,
7463 update the address and change to an indirect jump. */
7464 if (GET_CODE (PATTERN (insn)) == RETURN
7465 || (GET_CODE (PATTERN (insn)) == PARALLEL
7466 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
7468 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
7470 HOST_WIDE_INT offset = 0;
7471 rtx jump_insn, jump_set;
7473 /* If the return address is in a register, we can emit the insn
7474 unchanged. Otherwise, it must be a MEM and we see what the
7475 base register and offset are. In any case, we have to emit any
7476 pending load to the equivalent reg of SP, if any. */
7477 if (GET_CODE (retaddr) == REG)
7479 emit_equiv_load (&info);
7484 else if (GET_CODE (retaddr) == MEM
7485 && GET_CODE (XEXP (retaddr, 0)) == REG)
7486 base = gen_rtx_REG (Pmode, REGNO (XEXP (retaddr, 0))), offset = 0;
7487 else if (GET_CODE (retaddr) == MEM
7488 && GET_CODE (XEXP (retaddr, 0)) == PLUS
7489 && GET_CODE (XEXP (XEXP (retaddr, 0), 0)) == REG
7490 && GET_CODE (XEXP (XEXP (retaddr, 0), 1)) == CONST_INT)
7492 base = gen_rtx_REG (Pmode, REGNO (XEXP (XEXP (retaddr, 0), 0)));
7493 offset = INTVAL (XEXP (XEXP (retaddr, 0), 1));
7498 /* If the base of the location containing the return pointer
7499 is SP, we must update it with the replacement address. Otherwise,
7500 just build the necessary MEM. */
7501 retaddr = plus_constant (base, offset);
7502 if (base == stack_pointer_rtx)
7503 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
7504 plus_constant (info.sp_equiv_reg,
7507 retaddr = gen_rtx_MEM (Pmode, retaddr);
7509 /* If there is a pending load to the equivalent register for SP
7510 and we reference that register, we must load our address into
7511 a scratch register and then do that load. */
7512 if (info.equiv_reg_src
7513 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
7518 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
7519 if (HARD_REGNO_MODE_OK (regno, Pmode)
7520 && !fixed_regs[regno]
7521 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
7522 && !REGNO_REG_SET_P (EXIT_BLOCK_PTR->global_live_at_start,
7524 && !refers_to_regno_p (regno,
7525 regno + HARD_REGNO_NREGS (regno,
7527 info.equiv_reg_src, NULL)
7528 && info.const_equiv[regno] == 0)
7531 if (regno == FIRST_PSEUDO_REGISTER)
7534 reg = gen_rtx_REG (Pmode, regno);
7535 emit_move_insn (reg, retaddr);
7539 emit_equiv_load (&info);
7540 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
7542 /* Show the SET in the above insn is a RETURN. */
7543 jump_set = single_set (jump_insn);
7547 SET_IS_RETURN_P (jump_set) = 1;
7550 /* If SP is not mentioned in the pattern and its equivalent register, if
7551 any, is not modified, just emit it. Otherwise, if neither is set,
7552 replace the reference to SP and emit the insn. If none of those are
7553 true, handle each SET individually. */
7554 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
7555 && (info.sp_equiv_reg == stack_pointer_rtx
7556 || !reg_set_p (info.sp_equiv_reg, insn)))
7558 else if (! reg_set_p (stack_pointer_rtx, insn)
7559 && (info.sp_equiv_reg == stack_pointer_rtx
7560 || !reg_set_p (info.sp_equiv_reg, insn)))
7562 if (! validate_replace_rtx (stack_pointer_rtx,
7563 plus_constant (info.sp_equiv_reg,
7570 else if (GET_CODE (PATTERN (insn)) == SET)
7571 handle_epilogue_set (PATTERN (insn), &info);
7572 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
7574 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
7575 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
7576 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
7581 info.sp_equiv_reg = info.new_sp_equiv_reg;
7582 info.sp_offset = info.new_sp_offset;
7584 /* Now update any constants this insn sets. */
7585 note_stores (PATTERN (insn), update_epilogue_consts, &info);
7589 insns = get_insns ();
7594 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
7595 structure that contains information about what we've seen so far. We
7596 process this SET by either updating that data or by emitting one or
7600 handle_epilogue_set (rtx set, struct epi_info *p)
7602 /* First handle the case where we are setting SP. Record what it is being
7603 set from. If unknown, abort. */
7604 if (reg_set_p (stack_pointer_rtx, set))
7606 if (SET_DEST (set) != stack_pointer_rtx)
7609 if (GET_CODE (SET_SRC (set)) == PLUS)
7611 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
7612 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
7613 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
7614 else if (GET_CODE (XEXP (SET_SRC (set), 1)) == REG
7615 && REGNO (XEXP (SET_SRC (set), 1)) < FIRST_PSEUDO_REGISTER
7616 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))] != 0)
7618 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
7623 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
7625 /* If we are adjusting SP, we adjust from the old data. */
7626 if (p->new_sp_equiv_reg == stack_pointer_rtx)
7628 p->new_sp_equiv_reg = p->sp_equiv_reg;
7629 p->new_sp_offset += p->sp_offset;
7632 if (p->new_sp_equiv_reg == 0 || GET_CODE (p->new_sp_equiv_reg) != REG)
7638 /* Next handle the case where we are setting SP's equivalent register.
7639 If we already have a value to set it to, abort. We could update, but
7640 there seems little point in handling that case. Note that we have
7641 to allow for the case where we are setting the register set in
7642 the previous part of a PARALLEL inside a single insn. But use the
7643 old offset for any updates within this insn. We must allow for the case
7644 where the register is being set in a different (usually wider) mode than
7646 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
7648 if (p->equiv_reg_src != 0
7649 || GET_CODE (p->new_sp_equiv_reg) != REG
7650 || GET_CODE (SET_DEST (set)) != REG
7651 || GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) > BITS_PER_WORD
7652 || REGNO (p->new_sp_equiv_reg) != REGNO (SET_DEST (set)))
7656 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7657 plus_constant (p->sp_equiv_reg,
7661 /* Otherwise, replace any references to SP in the insn to its new value
7662 and emit the insn. */
7665 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7666 plus_constant (p->sp_equiv_reg,
7668 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
7669 plus_constant (p->sp_equiv_reg,
7675 /* Update the tracking information for registers set to constants. */
7678 update_epilogue_consts (rtx dest, rtx x, void *data)
7680 struct epi_info *p = (struct epi_info *) data;
7682 if (GET_CODE (dest) != REG || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
7684 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x))
7685 || GET_CODE (SET_SRC (x)) != CONST_INT)
7686 p->const_equiv[REGNO (dest)] = 0;
7688 p->const_equiv[REGNO (dest)] = SET_SRC (x);
7691 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
7694 emit_equiv_load (struct epi_info *p)
7696 if (p->equiv_reg_src != 0)
7698 rtx dest = p->sp_equiv_reg;
7700 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
7701 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
7702 REGNO (p->sp_equiv_reg));
7704 emit_move_insn (dest, p->equiv_reg_src);
7705 p->equiv_reg_src = 0;
7710 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
7711 this into place with notes indicating where the prologue ends and where
7712 the epilogue begins. Update the basic block information when possible. */
7715 thread_prologue_and_epilogue_insns (rtx f ATTRIBUTE_UNUSED)
7719 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
7722 #ifdef HAVE_prologue
7723 rtx prologue_end = NULL_RTX;
7725 #if defined (HAVE_epilogue) || defined(HAVE_return)
7726 rtx epilogue_end = NULL_RTX;
7729 #ifdef HAVE_prologue
7733 seq = gen_prologue ();
7736 /* Retain a map of the prologue insns. */
7737 record_insns (seq, &prologue);
7738 prologue_end = emit_note (NOTE_INSN_PROLOGUE_END);
7742 set_insn_locators (seq, prologue_locator);
7744 /* Can't deal with multiple successors of the entry block
7745 at the moment. Function should always have at least one
7747 if (!ENTRY_BLOCK_PTR->succ || ENTRY_BLOCK_PTR->succ->succ_next)
7750 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
7755 /* If the exit block has no non-fake predecessors, we don't need
7757 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7758 if ((e->flags & EDGE_FAKE) == 0)
7764 if (optimize && HAVE_return)
7766 /* If we're allowed to generate a simple return instruction,
7767 then by definition we don't need a full epilogue. Examine
7768 the block that falls through to EXIT. If it does not
7769 contain any code, examine its predecessors and try to
7770 emit (conditional) return instructions. */
7776 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7777 if (e->flags & EDGE_FALLTHRU)
7783 /* Verify that there are no active instructions in the last block. */
7784 label = BB_END (last);
7785 while (label && GET_CODE (label) != CODE_LABEL)
7787 if (active_insn_p (label))
7789 label = PREV_INSN (label);
7792 if (BB_HEAD (last) == label && GET_CODE (label) == CODE_LABEL)
7794 rtx epilogue_line_note = NULL_RTX;
7796 /* Locate the line number associated with the closing brace,
7797 if we can find one. */
7798 for (seq = get_last_insn ();
7799 seq && ! active_insn_p (seq);
7800 seq = PREV_INSN (seq))
7801 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
7803 epilogue_line_note = seq;
7807 for (e = last->pred; e; e = e_next)
7809 basic_block bb = e->src;
7812 e_next = e->pred_next;
7813 if (bb == ENTRY_BLOCK_PTR)
7817 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
7820 /* If we have an unconditional jump, we can replace that
7821 with a simple return instruction. */
7822 if (simplejump_p (jump))
7824 emit_return_into_block (bb, epilogue_line_note);
7828 /* If we have a conditional jump, we can try to replace
7829 that with a conditional return instruction. */
7830 else if (condjump_p (jump))
7832 if (! redirect_jump (jump, 0, 0))
7835 /* If this block has only one successor, it both jumps
7836 and falls through to the fallthru block, so we can't
7838 if (bb->succ->succ_next == NULL)
7844 /* Fix up the CFG for the successful change we just made. */
7845 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7848 /* Emit a return insn for the exit fallthru block. Whether
7849 this is still reachable will be determined later. */
7851 emit_barrier_after (BB_END (last));
7852 emit_return_into_block (last, epilogue_line_note);
7853 epilogue_end = BB_END (last);
7854 last->succ->flags &= ~EDGE_FALLTHRU;
7859 #ifdef HAVE_epilogue
7862 /* Find the edge that falls through to EXIT. Other edges may exist
7863 due to RETURN instructions, but those don't need epilogues.
7864 There really shouldn't be a mixture -- either all should have
7865 been converted or none, however... */
7867 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7868 if (e->flags & EDGE_FALLTHRU)
7874 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
7876 seq = gen_epilogue ();
7878 #ifdef INCOMING_RETURN_ADDR_RTX
7879 /* If this function returns with the stack depressed and we can support
7880 it, massage the epilogue to actually do that. */
7881 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
7882 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7883 seq = keep_stack_depressed (seq);
7886 emit_jump_insn (seq);
7888 /* Retain a map of the epilogue insns. */
7889 record_insns (seq, &epilogue);
7890 set_insn_locators (seq, epilogue_locator);
7895 insert_insn_on_edge (seq, e);
7902 commit_edge_insertions ();
7904 #ifdef HAVE_sibcall_epilogue
7905 /* Emit sibling epilogues before any sibling call sites. */
7906 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7908 basic_block bb = e->src;
7909 rtx insn = BB_END (bb);
7913 if (GET_CODE (insn) != CALL_INSN
7914 || ! SIBLING_CALL_P (insn))
7918 emit_insn (gen_sibcall_epilogue ());
7922 /* Retain a map of the epilogue insns. Used in life analysis to
7923 avoid getting rid of sibcall epilogue insns. Do this before we
7924 actually emit the sequence. */
7925 record_insns (seq, &sibcall_epilogue);
7926 set_insn_locators (seq, epilogue_locator);
7928 i = PREV_INSN (insn);
7929 newinsn = emit_insn_before (seq, insn);
7933 #ifdef HAVE_prologue
7934 /* This is probably all useless now that we use locators. */
7939 /* GDB handles `break f' by setting a breakpoint on the first
7940 line note after the prologue. Which means (1) that if
7941 there are line number notes before where we inserted the
7942 prologue we should move them, and (2) we should generate a
7943 note before the end of the first basic block, if there isn't
7946 ??? This behavior is completely broken when dealing with
7947 multiple entry functions. We simply place the note always
7948 into first basic block and let alternate entry points
7952 for (insn = prologue_end; insn; insn = prev)
7954 prev = PREV_INSN (insn);
7955 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7957 /* Note that we cannot reorder the first insn in the
7958 chain, since rest_of_compilation relies on that
7959 remaining constant. */
7962 reorder_insns (insn, insn, prologue_end);
7966 /* Find the last line number note in the first block. */
7967 for (insn = BB_END (ENTRY_BLOCK_PTR->next_bb);
7968 insn != prologue_end && insn;
7969 insn = PREV_INSN (insn))
7970 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7973 /* If we didn't find one, make a copy of the first line number
7977 for (insn = next_active_insn (prologue_end);
7979 insn = PREV_INSN (insn))
7980 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7982 emit_note_copy_after (insn, prologue_end);
7988 #ifdef HAVE_epilogue
7993 /* Similarly, move any line notes that appear after the epilogue.
7994 There is no need, however, to be quite so anal about the existence
7995 of such a note. Also move the NOTE_INSN_FUNCTION_END and (possibly)
7996 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
7998 for (insn = epilogue_end; insn; insn = next)
8000 next = NEXT_INSN (insn);
8001 if (GET_CODE (insn) == NOTE
8002 && (NOTE_LINE_NUMBER (insn) > 0
8003 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG
8004 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END))
8005 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
8011 /* Reposition the prologue-end and epilogue-begin notes after instruction
8012 scheduling and delayed branch scheduling. */
8015 reposition_prologue_and_epilogue_notes (rtx f ATTRIBUTE_UNUSED)
8017 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
8018 rtx insn, last, note;
8021 if ((len = VARRAY_SIZE (prologue)) > 0)
8025 /* Scan from the beginning until we reach the last prologue insn.
8026 We apparently can't depend on basic_block_{head,end} after
8028 for (insn = f; insn; insn = NEXT_INSN (insn))
8030 if (GET_CODE (insn) == NOTE)
8032 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
8035 else if (contains (insn, prologue))
8045 /* Find the prologue-end note if we haven't already, and
8046 move it to just after the last prologue insn. */
8049 for (note = last; (note = NEXT_INSN (note));)
8050 if (GET_CODE (note) == NOTE
8051 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
8055 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
8056 if (GET_CODE (last) == CODE_LABEL)
8057 last = NEXT_INSN (last);
8058 reorder_insns (note, note, last);
8062 if ((len = VARRAY_SIZE (epilogue)) > 0)
8066 /* Scan from the end until we reach the first epilogue insn.
8067 We apparently can't depend on basic_block_{head,end} after
8069 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
8071 if (GET_CODE (insn) == NOTE)
8073 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
8076 else if (contains (insn, epilogue))
8086 /* Find the epilogue-begin note if we haven't already, and
8087 move it to just before the first epilogue insn. */
8090 for (note = insn; (note = PREV_INSN (note));)
8091 if (GET_CODE (note) == NOTE
8092 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
8096 if (PREV_INSN (last) != note)
8097 reorder_insns (note, note, PREV_INSN (last));
8100 #endif /* HAVE_prologue or HAVE_epilogue */
8103 /* Called once, at initialization, to initialize function.c. */
8106 init_function_once (void)
8108 VARRAY_INT_INIT (prologue, 0, "prologue");
8109 VARRAY_INT_INIT (epilogue, 0, "epilogue");
8110 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");
8113 /* Returns the name of the current function. */
8115 current_function_name (void)
8117 return (*lang_hooks.decl_printable_name) (cfun->decl, 2);
8120 #include "gt-function.h"