Merge branch 'vendor/GCC44'
[dragonfly.git] / contrib / gcc-4.4 / gcc / reload.h
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c251ad9e
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1/* Communication between reload.c, reload1.c and the rest of compiler.
2 Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 1999,
3 2000, 2001, 2003, 2004, 2007, 2008 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 3, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING3. If not see
19<http://www.gnu.org/licenses/>. */
20
21
22/* If secondary reloads are the same for inputs and outputs, define those
23 macros here. */
24
25#ifdef SECONDARY_RELOAD_CLASS
26#define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
27 SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
28#define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
29 SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
30#endif
31
32/* If MEMORY_MOVE_COST isn't defined, give it a default here. */
33#ifndef MEMORY_MOVE_COST
34#define MEMORY_MOVE_COST(MODE,CLASS,IN) \
35 (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN)))
36#endif
37extern int memory_move_secondary_cost (enum machine_mode, enum reg_class, int);
38
39/* Maximum number of reloads we can need. */
40#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
41
42/* Encode the usage of a reload. The following codes are supported:
43
44 RELOAD_FOR_INPUT reload of an input operand
45 RELOAD_FOR_OUTPUT likewise, for output
46 RELOAD_FOR_INSN a reload that must not conflict with anything
47 used in the insn, but may conflict with
48 something used before or after the insn
49 RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object
50 that is an input reload
51 RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS
52 RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output
53 RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS
54 RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded
55 operand; these don't conflict with
56 any other addresses.
57 RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS
58 reloads; usually secondary reloads
59 RELOAD_OTHER none of the above, usually multiple uses
60 RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input
61 that is marked RELOAD_OTHER.
62
63 This used to be "enum reload_when_needed" but some debuggers have trouble
64 with an enum tag and variable of the same name. */
65
66enum reload_type
67{
68 RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN,
69 RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS,
70 RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS,
71 RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR,
72 RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
73};
74
75#ifdef GCC_INSN_CODES_H
76/* Each reload is recorded with a structure like this. */
77struct reload
78{
79 /* The value to reload from */
80 rtx in;
81 /* Where to store reload-reg afterward if nec (often the same as
82 reload_in) */
83 rtx out;
84
85 /* The class of registers to reload into. */
86 enum reg_class rclass;
87
88 /* The mode this operand should have when reloaded, on input. */
89 enum machine_mode inmode;
90 /* The mode this operand should have when reloaded, on output. */
91 enum machine_mode outmode;
92
93 /* The mode of the reload register. */
94 enum machine_mode mode;
95
96 /* the largest number of registers this reload will require. */
97 unsigned int nregs;
98
99 /* Positive amount to increment or decrement by if
100 reload_in is a PRE_DEC, PRE_INC, POST_DEC, POST_INC.
101 Ignored otherwise (don't assume it is zero). */
102 int inc;
103 /* A reg for which reload_in is the equivalent.
104 If reload_in is a symbol_ref which came from
105 reg_equiv_constant, then this is the pseudo
106 which has that symbol_ref as equivalent. */
107 rtx in_reg;
108 rtx out_reg;
109
110 /* Used in find_reload_regs to record the allocated register. */
111 int regno;
112 /* This is the register to reload into. If it is zero when `find_reloads'
113 returns, you must find a suitable register in the class specified by
114 reload_reg_class, and store here an rtx for that register with mode from
115 reload_inmode or reload_outmode. */
116 rtx reg_rtx;
117 /* The operand number being reloaded. This is used to group related reloads
118 and need not always be equal to the actual operand number in the insn,
119 though it current will be; for in-out operands, it is one of the two
120 operand numbers. */
121 int opnum;
122
123 /* Gives the reload number of a secondary input reload, when needed;
124 otherwise -1. */
125 int secondary_in_reload;
126 /* Gives the reload number of a secondary output reload, when needed;
127 otherwise -1. */
128 int secondary_out_reload;
129 /* If a secondary input reload is required, gives the INSN_CODE that uses the
130 secondary reload as a scratch register, or CODE_FOR_nothing if the
131 secondary reload register is to be an intermediate register. */
132 enum insn_code secondary_in_icode;
133 /* Likewise, for a secondary output reload. */
134 enum insn_code secondary_out_icode;
135
136 /* Classifies reload as needed either for addressing an input reload,
137 addressing an output, for addressing a non-reloaded mem ref, or for
138 unspecified purposes (i.e., more than one of the above). */
139 enum reload_type when_needed;
140
141 /* Nonzero for an optional reload. Optional reloads are ignored unless the
142 value is already sitting in a register. */
143 unsigned int optional:1;
144 /* nonzero if this reload shouldn't be combined with another reload. */
145 unsigned int nocombine:1;
146 /* Nonzero if this is a secondary register for one or more reloads. */
147 unsigned int secondary_p:1;
148 /* Nonzero if this reload must use a register not already allocated to a
149 group. */
150 unsigned int nongroup:1;
151};
152
153extern struct reload rld[MAX_RELOADS];
154extern int n_reloads;
155#endif
156
157extern GTY (()) VEC(rtx,gc) *reg_equiv_memory_loc_vec;
158extern rtx *reg_equiv_constant;
159extern rtx *reg_equiv_invariant;
160extern rtx *reg_equiv_memory_loc;
161extern rtx *reg_equiv_address;
162extern rtx *reg_equiv_mem;
163extern rtx *reg_equiv_alt_mem_list;
164
165/* Element N is the list of insns that initialized reg N from its equivalent
166 constant or memory slot. */
167extern GTY((length("reg_equiv_init_size"))) rtx *reg_equiv_init;
168
169/* The size of the previous array, for GC purposes. */
170extern GTY(()) int reg_equiv_init_size;
171
172/* All the "earlyclobber" operands of the current insn
173 are recorded here. */
174extern int n_earlyclobbers;
175extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
176
177/* Save the number of operands. */
178extern int reload_n_operands;
179
180/* First uid used by insns created by reload in this function.
181 Used in find_equiv_reg. */
182extern int reload_first_uid;
183
184/* Nonzero if indirect addressing is supported when the innermost MEM is
185 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
186 which these are valid is the same as spill_indirect_levels, above. */
187
188extern char indirect_symref_ok;
189
190/* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
191extern char double_reg_address_ok;
192
193extern int num_not_at_initial_offset;
194
195#if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET
196/* This structure describes instructions which are relevant for reload.
197 Apart from all regular insns, this also includes CODE_LABELs, since they
198 must be examined for register elimination. */
199struct insn_chain
200{
201 /* Links to the neighbor instructions. */
202 struct insn_chain *next, *prev;
203
204 /* Link through a chains set up by calculate_needs_all_insns, containing
205 all insns that need reloading. */
206 struct insn_chain *next_need_reload;
207
208 /* The rtx of the insn. */
209 rtx insn;
210
211 /* The basic block this insn is in. */
212 int block;
213
214 /* Nonzero if find_reloads said the insn requires reloading. */
215 unsigned int need_reload:1;
216 /* Nonzero if find_reloads needs to be run during reload_as_needed to
217 perform modifications on any operands. */
218 unsigned int need_operand_change:1;
219 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */
220 unsigned int need_elim:1;
221 /* Nonzero if this insn was inserted by perform_caller_saves. */
222 unsigned int is_caller_save_insn:1;
223
224 /* Register life information: record all live hard registers, and
225 all live pseudos that have a hard register. This set also
226 contains pseudos spilled by IRA. */
227 regset_head live_throughout;
228 regset_head dead_or_set;
229
230 /* Copies of the global variables computed by find_reloads. */
231 struct reload *rld;
232 int n_reloads;
233
234 /* Indicates which registers have already been used for spills. */
235 HARD_REG_SET used_spill_regs;
236};
237
238/* A chain of insn_chain structures to describe all non-note insns in
239 a function. */
240extern struct insn_chain *reload_insn_chain;
241
242/* Allocate a new insn_chain structure. */
243extern struct insn_chain *new_insn_chain (void);
244
245extern void compute_use_by_pseudos (HARD_REG_SET *, regset);
246#endif
247
248/* Functions from reload.c: */
249
250extern enum reg_class secondary_reload_class (bool, enum reg_class,
251 enum machine_mode, rtx);
252
253#ifdef GCC_INSN_CODES_H
254extern enum reg_class scratch_reload_class (enum insn_code);
255#endif
256
257/* Return a memory location that will be used to copy X in mode MODE.
258 If we haven't already made a location for this mode in this insn,
259 call find_reloads_address on the location being returned. */
260extern rtx get_secondary_mem (rtx, enum machine_mode, int, enum reload_type);
261
262/* Clear any secondary memory locations we've made. */
263extern void clear_secondary_mem (void);
264
265/* Transfer all replacements that used to be in reload FROM to be in
266 reload TO. */
267extern void transfer_replacements (int, int);
268
269/* IN_RTX is the value loaded by a reload that we now decided to inherit,
270 or a subpart of it. If we have any replacements registered for IN_RTX,
271 cancel the reloads that were supposed to load them.
272 Return nonzero if we canceled any reloads. */
273extern int remove_address_replacements (rtx in_rtx);
274
275/* Like rtx_equal_p except that it allows a REG and a SUBREG to match
276 if they are the same hard reg, and has special hacks for
277 autoincrement and autodecrement. */
278extern int operands_match_p (rtx, rtx);
279
280/* Return 1 if altering OP will not modify the value of CLOBBER. */
281extern int safe_from_earlyclobber (rtx, rtx);
282
283/* Search the body of INSN for values that need reloading and record them
284 with push_reload. REPLACE nonzero means record also where the values occur
285 so that subst_reloads can be used. */
286extern int find_reloads (rtx, int, int, int, short *);
287
288/* Compute the sum of X and Y, making canonicalizations assumed in an
289 address, namely: sum constant integers, surround the sum of two
290 constants with a CONST, put the constant as the second operand, and
291 group the constant on the outermost sum. */
292extern rtx form_sum (rtx, rtx);
293
294/* Substitute into the current INSN the registers into which we have reloaded
295 the things that need reloading. */
296extern void subst_reloads (rtx);
297
298/* Make a copy of any replacements being done into X and move those copies
299 to locations in Y, a copy of X. We only look at the highest level of
300 the RTL. */
301extern void copy_replacements (rtx, rtx);
302
303/* Change any replacements being done to *X to be done to *Y */
304extern void move_replacements (rtx *x, rtx *y);
305
306/* If LOC was scheduled to be replaced by something, return the replacement.
307 Otherwise, return *LOC. */
308extern rtx find_replacement (rtx *);
309
310/* Nonzero if modifying X will affect IN. */
311extern int reg_overlap_mentioned_for_reload_p (rtx, rtx);
312
313/* Check the insns before INSN to see if there is a suitable register
314 containing the same value as GOAL. */
315extern rtx find_equiv_reg (rtx, rtx, enum reg_class, int, short *,
316 int, enum machine_mode);
317
318/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */
319extern int regno_clobbered_p (unsigned int, rtx, enum machine_mode, int);
320
321/* Return 1 if X is an operand of an insn that is being earlyclobbered. */
322extern int earlyclobber_operand_p (rtx);
323
324/* Record one reload that needs to be performed. */
325extern int push_reload (rtx, rtx, rtx *, rtx *, enum reg_class,
326 enum machine_mode, enum machine_mode,
327 int, int, int, enum reload_type);
328
329/* Functions in postreload.c: */
330extern void reload_cse_regs (rtx);
331
332/* Functions in reload1.c: */
333
334/* Initialize the reload pass once per compilation. */
335extern void init_reload (void);
336
337/* The reload pass itself. */
338extern int reload (rtx, int);
339
340/* Mark the slots in regs_ever_live for the hard regs
341 used by pseudo-reg number REGNO. */
342extern void mark_home_live (int);
343
344/* Scan X and replace any eliminable registers (such as fp) with a
345 replacement (such as sp), plus an offset. */
346extern rtx eliminate_regs (rtx, enum machine_mode, rtx);
347extern bool elimination_target_reg_p (rtx);
348
349/* Deallocate the reload register used by reload number R. */
350extern void deallocate_reload_reg (int r);
351
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352/* True if caller-save has been reinitialized. */
353extern bool caller_save_initialized_p;
354
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355/* Functions in caller-save.c: */
356
357/* Initialize for caller-save. */
358extern void init_caller_save (void);
359
360/* Initialize save areas by showing that we haven't allocated any yet. */
361extern void init_save_areas (void);
362
363/* Allocate save areas for any hard registers that might need saving. */
364extern void setup_save_areas (void);
365
366/* Find the places where hard regs are live across calls and save them. */
367extern void save_call_clobbered_regs (void);
368
369/* Replace (subreg (reg)) with the appropriate (reg) for any operands. */
370extern void cleanup_subreg_operands (rtx);
371
372/* Debugging support. */
373extern void debug_reload_to_stream (FILE *);
374extern void debug_reload (void);
375
376/* Compute the actual register we should reload to, in case we're
377 reloading to/from a register that is wider than a word. */
378extern rtx reload_adjust_reg_for_mode (rtx, enum machine_mode);