Daily bump.
[official-gcc.git] / 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 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
10 version.
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
15 for more details.
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
20 02111-1307, USA. */
23 /* If secondary reloads are the same for inputs and outputs, define those
24 macros here. */
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
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
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
47 extern int memory_move_secondary_cost PARAMS ((enum machine_mode, enum reg_class, int));
49 /* Maximum number of reloads we can need. */
50 #define MAX_RELOADS (2 * MAX_RECOG_OPERANDS * (MAX_REGS_PER_ADDRESS + 1))
52 /* Encode the usage of a reload. The following codes are supported:
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.
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. */
76 enum reload_type
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
85 #ifdef GCC_INSN_CODES_H
86 /* Each reload is recorded with a structure like this. */
87 struct reload
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;
95 /* The class of registers to reload into. */
96 enum reg_class class;
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;
103 /* The mode of the reload register. */
104 enum machine_mode mode;
106 /* the largest number of registers this reload will require. */
107 unsigned int nregs;
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;
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;
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;
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;
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;
163 extern struct reload rld[MAX_RELOADS];
164 extern int n_reloads;
165 #endif
167 extern rtx *reg_equiv_constant;
168 extern rtx *reg_equiv_memory_loc;
169 extern rtx *reg_equiv_address;
170 extern rtx *reg_equiv_mem;
172 /* All the "earlyclobber" operands of the current insn
173 are recorded here. */
174 extern int n_earlyclobbers;
175 extern rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
177 /* Save the number of operands. */
178 extern int reload_n_operands;
180 /* First uid used by insns created by reload in this function.
181 Used in find_equiv_reg. */
182 extern int reload_first_uid;
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. */
188 extern char indirect_symref_ok;
190 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
191 extern char double_reg_address_ok;
193 extern int num_not_at_initial_offset;
195 struct needs
197 /* [0] is normal, [1] is nongroup. */
198 short regs[2][N_REG_CLASSES];
199 short groups[N_REG_CLASSES];
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. */
206 struct insn_chain
208 /* Links to the neighbour instructions. */
209 struct insn_chain *next, *prev;
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;
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;
224 /* Copies of the global variables computed by find_reloads. */
225 struct reload *rld;
226 int n_reloads;
228 /* Indicates which registers have already been used for spills. */
229 HARD_REG_SET used_spill_regs;
231 /* Describe the needs for reload registers of this insn. */
232 struct needs need;
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;
245 /* A chain of insn_chain structures to describe all non-note insns in
246 a function. */
247 extern struct insn_chain *reload_insn_chain;
249 /* Allocate a new insn_chain structure. */
250 extern struct insn_chain *new_insn_chain PARAMS ((void));
252 extern void compute_use_by_pseudos PARAMS ((HARD_REG_SET *, regset));
253 #endif
255 /* Functions from reload.c: */
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. */
260 extern rtx get_secondary_mem PARAMS ((rtx, enum machine_mode,
261 int, enum reload_type));
263 /* Clear any secondary memory locations we've made. */
264 extern void clear_secondary_mem PARAMS ((void));
266 /* Transfer all replacements that used to be in reload FROM to be in
267 reload TO. */
268 extern void transfer_replacements PARAMS ((int, int));
270 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
271 or a subpart of it. If we have any replacements registered for IN_RTX,
272 chancel the reloads that were supposed to load them.
273 Return non-zero if we chanceled any reloads. */
274 extern int remove_address_replacements PARAMS ((rtx in_rtx));
276 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
277 if they are the same hard reg, and has special hacks for
278 autoincrement and autodecrement. */
279 extern int operands_match_p PARAMS ((rtx, rtx));
281 /* Return 1 if altering OP will not modify the value of CLOBBER. */
282 extern int safe_from_earlyclobber PARAMS ((rtx, rtx));
284 /* Search the body of INSN for values that need reloading and record them
285 with push_reload. REPLACE nonzero means record also where the values occur
286 so that subst_reloads can be used. */
287 extern int find_reloads PARAMS ((rtx, int, int, int, short *));
289 /* Compute the sum of X and Y, making canonicalizations assumed in an
290 address, namely: sum constant integers, surround the sum of two
291 constants with a CONST, put the constant as the second operand, and
292 group the constant on the outermost sum. */
293 extern rtx form_sum PARAMS ((rtx, rtx));
295 /* Substitute into the current INSN the registers into which we have reloaded
296 the things that need reloading. */
297 extern void subst_reloads PARAMS ((rtx));
299 /* Make a copy of any replacements being done into X and move those copies
300 to locations in Y, a copy of X. We only look at the highest level of
301 the RTL. */
302 extern void copy_replacements PARAMS ((rtx, rtx));
304 /* Change any replacements being done to *X to be done to *Y */
305 extern void move_replacements PARAMS ((rtx *x, rtx *y));
307 /* If LOC was scheduled to be replaced by something, return the replacement.
308 Otherwise, return *LOC. */
309 extern rtx find_replacement PARAMS ((rtx *));
311 /* Return nonzero if register in range [REGNO, ENDREGNO)
312 appears either explicitly or implicitly in X
313 other than being stored into. */
314 extern int refers_to_regno_for_reload_p PARAMS ((unsigned int, unsigned int,
315 rtx, rtx *));
317 /* Nonzero if modifying X will affect IN. */
318 extern int reg_overlap_mentioned_for_reload_p PARAMS ((rtx, rtx));
320 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
321 registers. */
322 extern int refers_to_mem_for_reload_p PARAMS ((rtx));
324 /* Check the insns before INSN to see if there is a suitable register
325 containing the same value as GOAL. */
326 extern rtx find_equiv_reg PARAMS ((rtx, rtx, enum reg_class, int, short *,
327 int, enum machine_mode));
329 /* Return 1 if register REGNO is the subject of a clobber in insn INSN. */
330 extern int regno_clobbered_p PARAMS ((unsigned int, rtx, enum machine_mode,
331 int));
333 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
334 extern int earlyclobber_operand_p PARAMS ((rtx));
336 /* Record one reload that needs to be performed. */
337 extern int push_reload PARAMS ((rtx, rtx, rtx *, rtx *, enum reg_class,
338 enum machine_mode, enum machine_mode,
339 int, int, int, enum reload_type));
341 /* Functions in reload1.c: */
343 extern void reload_cse_regs PARAMS ((rtx));
344 extern int reloads_conflict PARAMS ((int, int));
346 /* Initialize the reload pass once per compilation. */
347 extern void init_reload PARAMS ((void));
349 /* The reload pass itself. */
350 extern int reload PARAMS ((rtx, int));
352 /* Mark the slots in regs_ever_live for the hard regs
353 used by pseudo-reg number REGNO. */
354 extern void mark_home_live PARAMS ((int));
356 /* Scan X and replace any eliminable registers (such as fp) with a
357 replacement (such as sp), plus an offset. */
358 extern rtx eliminate_regs PARAMS ((rtx, enum machine_mode, rtx));
360 /* Emit code to perform a reload from IN (which may be a reload register) to
361 OUT (which may also be a reload register). IN or OUT is from operand
362 OPNUM with reload type TYPE. */
363 extern rtx gen_reload PARAMS ((rtx, rtx, int, enum reload_type));
365 /* Deallocate the reload register used by reload number R. */
366 extern void deallocate_reload_reg PARAMS ((int r));
368 /* Functions in caller-save.c: */
370 /* Initialize for caller-save. */
371 extern void init_caller_save PARAMS ((void));
373 /* Initialize save areas by showing that we haven't allocated any yet. */
374 extern void init_save_areas PARAMS ((void));
376 /* Allocate save areas for any hard registers that might need saving. */
377 extern void setup_save_areas PARAMS ((void));
379 /* Find the places where hard regs are live across calls and save them. */
380 extern void save_call_clobbered_regs PARAMS ((void));
382 /* Replace (subreg (reg)) with the appropriate (reg) for any operands. */
383 extern void cleanup_subreg_operands PARAMS ((rtx));
385 /* Debugging support. */
386 extern void debug_reload_to_stream PARAMS ((FILE *));
387 extern void debug_reload PARAMS ((void));