Merge branch 'master' of ssh://crater.dragonflybsd.org/repository/git/dragonfly
[dragonfly.git] / contrib / gcc-3.4 / gcc / reload.h
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1/* Communication between reload.c and reload1.c.
2 Copyright (C) 1987, 1991, 1992, 1993, 1994, 1995, 1997, 1998,
3 1999, 2000, 2001, 2003 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 2, 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 COPYING. If not, write to the Free
19Software Foundation, 59 Temple Place - Suite 330, Boston, MA
2002111-1307, USA. */
21
22
23/* If secondary reloads are the same for inputs and outputs, define those
24 macros here. */
25
26#ifdef SECONDARY_RELOAD_CLASS
27#define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
28 SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
29#define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
30 SECONDARY_RELOAD_CLASS (CLASS, MODE, X)
31#endif
32
33/* If either macro is defined, show that we need secondary reloads. */
34#if defined(SECONDARY_INPUT_RELOAD_CLASS) || defined(SECONDARY_OUTPUT_RELOAD_CLASS)
35#define HAVE_SECONDARY_RELOADS
36#endif
37
38/* If MEMORY_MOVE_COST isn't defined, give it a default here. */
39#ifndef MEMORY_MOVE_COST
40#ifdef HAVE_SECONDARY_RELOADS
41#define MEMORY_MOVE_COST(MODE,CLASS,IN) \
42 (4 + memory_move_secondary_cost ((MODE), (CLASS), (IN)))
43#else
44#define MEMORY_MOVE_COST(MODE,CLASS,IN) 4
45#endif
46#endif
47extern int memory_move_secondary_cost (enum machine_mode, enum reg_class, int);
48
49/* Maximum number of reloads we can need. */
50#define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
51
52/* Encode the usage of a reload. The following codes are supported:
53
54 RELOAD_FOR_INPUT reload of an input operand
55 RELOAD_FOR_OUTPUT likewise, for output
56 RELOAD_FOR_INSN a reload that must not conflict with anything
57 used in the insn, but may conflict with
58 something used before or after the insn
59 RELOAD_FOR_INPUT_ADDRESS reload for parts of the address of an object
60 that is an input reload
61 RELOAD_FOR_INPADDR_ADDRESS reload needed for RELOAD_FOR_INPUT_ADDRESS
62 RELOAD_FOR_OUTPUT_ADDRESS like RELOAD_FOR INPUT_ADDRESS, for output
63 RELOAD_FOR_OUTADDR_ADDRESS reload needed for RELOAD_FOR_OUTPUT_ADDRESS
64 RELOAD_FOR_OPERAND_ADDRESS reload for the address of a non-reloaded
65 operand; these don't conflict with
66 any other addresses.
67 RELOAD_FOR_OPADDR_ADDR reload needed for RELOAD_FOR_OPERAND_ADDRESS
68 reloads; usually secondary reloads
69 RELOAD_OTHER none of the above, usually multiple uses
70 RELOAD_FOR_OTHER_ADDRESS reload for part of the address of an input
71 that is marked RELOAD_OTHER.
72
73 This used to be "enum reload_when_needed" but some debuggers have trouble
74 with an enum tag and variable of the same name. */
75
76enum reload_type
77{
78 RELOAD_FOR_INPUT, RELOAD_FOR_OUTPUT, RELOAD_FOR_INSN,
79 RELOAD_FOR_INPUT_ADDRESS, RELOAD_FOR_INPADDR_ADDRESS,
80 RELOAD_FOR_OUTPUT_ADDRESS, RELOAD_FOR_OUTADDR_ADDRESS,
81 RELOAD_FOR_OPERAND_ADDRESS, RELOAD_FOR_OPADDR_ADDR,
82 RELOAD_OTHER, RELOAD_FOR_OTHER_ADDRESS
83};
84
85#ifdef GCC_INSN_CODES_H
86/* Each reload is recorded with a structure like this. */
87struct reload
88{
89 /* The value to reload from */
90 rtx in;
91 /* Where to store reload-reg afterward if nec (often the same as
92 reload_in) */
93 rtx out;
94
95 /* The class of registers to reload into. */
96 enum reg_class class;
97
98 /* The mode this operand should have when reloaded, on input. */
99 enum machine_mode inmode;
100 /* The mode this operand should have when reloaded, on output. */
101 enum machine_mode outmode;
102
103 /* The mode of the reload register. */
104 enum machine_mode mode;
105
106 /* the largest number of registers this reload will require. */
107 unsigned int nregs;
108
109 /* Positive amount to increment or decrement by if
110 reload_in is a PRE_DEC, PRE_INC, POST_DEC, POST_INC.
111 Ignored otherwise (don't assume it is zero). */
112 int inc;
113 /* A reg for which reload_in is the equivalent.
114 If reload_in is a symbol_ref which came from
115 reg_equiv_constant, then this is the pseudo
116 which has that symbol_ref as equivalent. */
117 rtx in_reg;
118 rtx out_reg;
119
120 /* Used in find_reload_regs to record the allocated register. */
121 int regno;
122 /* This is the register to reload into. If it is zero when `find_reloads'
123 returns, you must find a suitable register in the class specified by
124 reload_reg_class, and store here an rtx for that register with mode from
125 reload_inmode or reload_outmode. */
126 rtx reg_rtx;
127 /* The operand number being reloaded. This is used to group related reloads
128 and need not always be equal to the actual operand number in the insn,
129 though it current will be; for in-out operands, it is one of the two
130 operand numbers. */
131 int opnum;
132
133 /* Gives the reload number of a secondary input reload, when needed;
134 otherwise -1. */
135 int secondary_in_reload;
136 /* Gives the reload number of a secondary output reload, when needed;
137 otherwise -1. */
138 int secondary_out_reload;
139 /* If a secondary input reload is required, gives the INSN_CODE that uses the
140 secondary reload as a scratch register, or CODE_FOR_nothing if the
141 secondary reload register is to be an intermediate register. */
142 enum insn_code secondary_in_icode;
143 /* Likewise, for a secondary output reload. */
144 enum insn_code secondary_out_icode;
145
146 /* Classifies reload as needed either for addressing an input reload,
147 addressing an output, for addressing a non-reloaded mem ref, or for
148 unspecified purposes (i.e., more than one of the above). */
149 enum reload_type when_needed;
150
151 /* Nonzero for an optional reload. Optional reloads are ignored unless the
152 value is already sitting in a register. */
153 unsigned int optional:1;
154 /* nonzero if this reload shouldn't be combined with another reload. */
155 unsigned int nocombine:1;
156 /* Nonzero if this is a secondary register for one or more reloads. */
157 unsigned int secondary_p:1;
158 /* Nonzero if this reload must use a register not already allocated to a
159 group. */
160 unsigned int nongroup:1;
161};
162
163extern struct reload rld[MAX_RELOADS];
164extern int n_reloads;
165#endif
166
167extern rtx *reg_equiv_constant;
168extern rtx *reg_equiv_memory_loc;
169extern rtx *reg_equiv_address;
170extern rtx *reg_equiv_mem;
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
195struct needs
196{
197 /* [0] is normal, [1] is nongroup. */
198 short regs[2][N_REG_CLASSES];
199 short groups[N_REG_CLASSES];
200};
201
202#if defined SET_HARD_REG_BIT && defined CLEAR_REG_SET
203/* This structure describes instructions which are relevant for reload.
204 Apart from all regular insns, this also includes CODE_LABELs, since they
205 must be examined for register elimination. */
206struct insn_chain
207{
208 /* Links to the neighbor instructions. */
209 struct insn_chain *next, *prev;
210
211 /* Link through a chains set up by calculate_needs_all_insns, containing
212 all insns that need reloading. */
213 struct insn_chain *next_need_reload;
214
215 /* The basic block this insn is in. */
216 int block;
217 /* The rtx of the insn. */
218 rtx insn;
219 /* Register life information: record all live hard registers, and all
220 live pseudos that have a hard register. */
221 regset_head live_throughout;
222 regset_head dead_or_set;
223
224 /* Copies of the global variables computed by find_reloads. */
225 struct reload *rld;
226 int n_reloads;
227
228 /* Indicates which registers have already been used for spills. */
229 HARD_REG_SET used_spill_regs;
230
231 /* Describe the needs for reload registers of this insn. */
232 struct needs need;
233
234 /* Nonzero if find_reloads said the insn requires reloading. */
235 unsigned int need_reload:1;
236 /* Nonzero if find_reloads needs to be run during reload_as_needed to
237 perform modifications on any operands. */
238 unsigned int need_operand_change:1;
239 /* Nonzero if eliminate_regs_in_insn said it requires eliminations. */
240 unsigned int need_elim:1;
241 /* Nonzero if this insn was inserted by perform_caller_saves. */
242 unsigned int is_caller_save_insn:1;
243};
244
245/* A chain of insn_chain structures to describe all non-note insns in
246 a function. */
247extern struct insn_chain *reload_insn_chain;
248
249/* Allocate a new insn_chain structure. */
250extern struct insn_chain *new_insn_chain (void);
251
252extern void compute_use_by_pseudos (HARD_REG_SET *, regset);
253#endif
254
255/* Functions from reload.c: */
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/* Return nonzero if register in range [REGNO, ENDREGNO)
311 appears either explicitly or implicitly in X
312 other than being stored into. */
313extern int refers_to_regno_for_reload_p (unsigned int, unsigned int,
314 rtx, rtx *);
315
316/* Nonzero if modifying X will affect IN. */
317extern int reg_overlap_mentioned_for_reload_p (rtx, rtx);
318
319/* Return nonzero if anything in X contains a MEM. Look also for pseudo
320 registers. */
321extern int refers_to_mem_for_reload_p (rtx);
322
323/* Check the insns before INSN to see if there is a suitable register
324 containing the same value as GOAL. */
325extern rtx find_equiv_reg (rtx, rtx, enum reg_class, int, short *,
326 int, enum machine_mode);
327
328/* Return 1 if register REGNO is the subject of a clobber in insn INSN. */
329extern int regno_clobbered_p (unsigned int, rtx, enum machine_mode, int);
330
331/* Return 1 if X is an operand of an insn that is being earlyclobbered. */
332extern int earlyclobber_operand_p (rtx);
333
334/* Record one reload that needs to be performed. */
335extern int push_reload (rtx, rtx, rtx *, rtx *, enum reg_class,
336 enum machine_mode, enum machine_mode,
337 int, int, int, enum reload_type);
338
339/* Functions in postreload.c: */
340extern void reload_cse_regs (rtx);
341
342/* Functions in reload1.c: */
343extern int reloads_conflict (int, int);
344
345/* Initialize the reload pass once per compilation. */
346extern void init_reload (void);
347
348/* The reload pass itself. */
349extern int reload (rtx, int);
350
351/* Mark the slots in regs_ever_live for the hard regs
352 used by pseudo-reg number REGNO. */
353extern void mark_home_live (int);
354
355/* Scan X and replace any eliminable registers (such as fp) with a
356 replacement (such as sp), plus an offset. */
357extern rtx eliminate_regs (rtx, enum machine_mode, rtx);
358
359/* Emit code to perform a reload from IN (which may be a reload register) to
360 OUT (which may also be a reload register). IN or OUT is from operand
361 OPNUM with reload type TYPE. */
362extern rtx gen_reload (rtx, rtx, int, enum reload_type);
363
364/* Deallocate the reload register used by reload number R. */
365extern void deallocate_reload_reg (int r);
366
367/* Functions in caller-save.c: */
368
369/* Initialize for caller-save. */
370extern void init_caller_save (void);
371
372/* Initialize save areas by showing that we haven't allocated any yet. */
373extern void init_save_areas (void);
374
375/* Allocate save areas for any hard registers that might need saving. */
376extern void setup_save_areas (void);
377
378/* Find the places where hard regs are live across calls and save them. */
379extern void save_call_clobbered_regs (void);
380
381/* Replace (subreg (reg)) with the appropriate (reg) for any operands. */
382extern void cleanup_subreg_operands (rtx);
383
384/* Debugging support. */
385extern void debug_reload_to_stream (FILE *);
386extern void debug_reload (void);
387
388/* Compute the actual register we should reload to, in case we're
389 reloading to/from a register that is wider than a word. */
390extern rtx reload_adjust_reg_for_mode (rtx, enum machine_mode);