* genattrtab.c (simplify_cond): Make TESTS an array of rtxs, instead
[official-gcc.git] / gcc / reload.c
blob6ca7322806ed8df42fdbec00b34a4174d2cd3bfe
1 /* Search an insn for pseudo regs that must be in hard regs and are not.
2 Copyright (C) 1987, 88, 89, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
9 any later version.
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
22 /* This file contains subroutines used only from the file reload1.c.
23 It knows how to scan one insn for operands and values
24 that need to be copied into registers to make valid code.
25 It also finds other operands and values which are valid
26 but for which equivalent values in registers exist and
27 ought to be used instead.
29 Before processing the first insn of the function, call `init_reload'.
31 To scan an insn, call `find_reloads'. This does two things:
32 1. sets up tables describing which values must be reloaded
33 for this insn, and what kind of hard regs they must be reloaded into;
34 2. optionally record the locations where those values appear in
35 the data, so they can be replaced properly later.
36 This is done only if the second arg to `find_reloads' is nonzero.
38 The third arg to `find_reloads' specifies the number of levels
39 of indirect addressing supported by the machine. If it is zero,
40 indirect addressing is not valid. If it is one, (MEM (REG n))
41 is valid even if (REG n) did not get a hard register; if it is two,
42 (MEM (MEM (REG n))) is also valid even if (REG n) did not get a
43 hard register, and similarly for higher values.
45 Then you must choose the hard regs to reload those pseudo regs into,
46 and generate appropriate load insns before this insn and perhaps
47 also store insns after this insn. Set up the array `reload_reg_rtx'
48 to contain the REG rtx's for the registers you used. In some
49 cases `find_reloads' will return a nonzero value in `reload_reg_rtx'
50 for certain reloads. Then that tells you which register to use,
51 so you do not need to allocate one. But you still do need to add extra
52 instructions to copy the value into and out of that register.
54 Finally you must call `subst_reloads' to substitute the reload reg rtx's
55 into the locations already recorded.
57 NOTE SIDE EFFECTS:
59 find_reloads can alter the operands of the instruction it is called on.
61 1. Two operands of any sort may be interchanged, if they are in a
62 commutative instruction.
63 This happens only if find_reloads thinks the instruction will compile
64 better that way.
66 2. Pseudo-registers that are equivalent to constants are replaced
67 with those constants if they are not in hard registers.
69 1 happens every time find_reloads is called.
70 2 happens only when REPLACE is 1, which is only when
71 actually doing the reloads, not when just counting them.
74 Using a reload register for several reloads in one insn:
76 When an insn has reloads, it is considered as having three parts:
77 the input reloads, the insn itself after reloading, and the output reloads.
78 Reloads of values used in memory addresses are often needed for only one part.
80 When this is so, reload_when_needed records which part needs the reload.
81 Two reloads for different parts of the insn can share the same reload
82 register.
84 When a reload is used for addresses in multiple parts, or when it is
85 an ordinary operand, it is classified as RELOAD_OTHER, and cannot share
86 a register with any other reload. */
88 #define REG_OK_STRICT
90 #include "config.h"
91 #include "system.h"
92 #include "rtl.h"
93 #include "tm_p.h"
94 #include "insn-config.h"
95 #include "insn-codes.h"
96 #include "recog.h"
97 #include "reload.h"
98 #include "regs.h"
99 #include "hard-reg-set.h"
100 #include "flags.h"
101 #include "real.h"
102 #include "output.h"
103 #include "function.h"
104 #include "expr.h"
105 #include "toplev.h"
107 #ifndef REGISTER_MOVE_COST
108 #define REGISTER_MOVE_COST(x, y) 2
109 #endif
111 #ifndef REGNO_MODE_OK_FOR_BASE_P
112 #define REGNO_MODE_OK_FOR_BASE_P(REGNO, MODE) REGNO_OK_FOR_BASE_P (REGNO)
113 #endif
115 #ifndef REG_MODE_OK_FOR_BASE_P
116 #define REG_MODE_OK_FOR_BASE_P(REGNO, MODE) REG_OK_FOR_BASE_P (REGNO)
117 #endif
119 /* All reloads of the current insn are recorded here. See reload.h for
120 comments. */
121 int n_reloads;
122 struct reload rld[MAX_RELOADS];
124 /* All the "earlyclobber" operands of the current insn
125 are recorded here. */
126 int n_earlyclobbers;
127 rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
129 int reload_n_operands;
131 /* Replacing reloads.
133 If `replace_reloads' is nonzero, then as each reload is recorded
134 an entry is made for it in the table `replacements'.
135 Then later `subst_reloads' can look through that table and
136 perform all the replacements needed. */
138 /* Nonzero means record the places to replace. */
139 static int replace_reloads;
141 /* Each replacement is recorded with a structure like this. */
142 struct replacement
144 rtx *where; /* Location to store in */
145 rtx *subreg_loc; /* Location of SUBREG if WHERE is inside
146 a SUBREG; 0 otherwise. */
147 int what; /* which reload this is for */
148 enum machine_mode mode; /* mode it must have */
151 static struct replacement replacements[MAX_RECOG_OPERANDS * ((MAX_REGS_PER_ADDRESS * 2) + 1)];
153 /* Number of replacements currently recorded. */
154 static int n_replacements;
156 /* Used to track what is modified by an operand. */
157 struct decomposition
159 int reg_flag; /* Nonzero if referencing a register. */
160 int safe; /* Nonzero if this can't conflict with anything. */
161 rtx base; /* Base address for MEM. */
162 HOST_WIDE_INT start; /* Starting offset or register number. */
163 HOST_WIDE_INT end; /* Ending offset or register number. */
166 #ifdef SECONDARY_MEMORY_NEEDED
168 /* Save MEMs needed to copy from one class of registers to another. One MEM
169 is used per mode, but normally only one or two modes are ever used.
171 We keep two versions, before and after register elimination. The one
172 after register elimination is record separately for each operand. This
173 is done in case the address is not valid to be sure that we separately
174 reload each. */
176 static rtx secondary_memlocs[NUM_MACHINE_MODES];
177 static rtx secondary_memlocs_elim[NUM_MACHINE_MODES][MAX_RECOG_OPERANDS];
178 #endif
180 /* The instruction we are doing reloads for;
181 so we can test whether a register dies in it. */
182 static rtx this_insn;
184 /* Nonzero if this instruction is a user-specified asm with operands. */
185 static int this_insn_is_asm;
187 /* If hard_regs_live_known is nonzero,
188 we can tell which hard regs are currently live,
189 at least enough to succeed in choosing dummy reloads. */
190 static int hard_regs_live_known;
192 /* Indexed by hard reg number,
193 element is nonnegative if hard reg has been spilled.
194 This vector is passed to `find_reloads' as an argument
195 and is not changed here. */
196 static short *static_reload_reg_p;
198 /* Set to 1 in subst_reg_equivs if it changes anything. */
199 static int subst_reg_equivs_changed;
201 /* On return from push_reload, holds the reload-number for the OUT
202 operand, which can be different for that from the input operand. */
203 static int output_reloadnum;
205 /* Compare two RTX's. */
206 #define MATCHES(x, y) \
207 (x == y || (x != 0 && (GET_CODE (x) == REG \
208 ? GET_CODE (y) == REG && REGNO (x) == REGNO (y) \
209 : rtx_equal_p (x, y) && ! side_effects_p (x))))
211 /* Indicates if two reloads purposes are for similar enough things that we
212 can merge their reloads. */
213 #define MERGABLE_RELOADS(when1, when2, op1, op2) \
214 ((when1) == RELOAD_OTHER || (when2) == RELOAD_OTHER \
215 || ((when1) == (when2) && (op1) == (op2)) \
216 || ((when1) == RELOAD_FOR_INPUT && (when2) == RELOAD_FOR_INPUT) \
217 || ((when1) == RELOAD_FOR_OPERAND_ADDRESS \
218 && (when2) == RELOAD_FOR_OPERAND_ADDRESS) \
219 || ((when1) == RELOAD_FOR_OTHER_ADDRESS \
220 && (when2) == RELOAD_FOR_OTHER_ADDRESS))
222 /* Nonzero if these two reload purposes produce RELOAD_OTHER when merged. */
223 #define MERGE_TO_OTHER(when1, when2, op1, op2) \
224 ((when1) != (when2) \
225 || ! ((op1) == (op2) \
226 || (when1) == RELOAD_FOR_INPUT \
227 || (when1) == RELOAD_FOR_OPERAND_ADDRESS \
228 || (when1) == RELOAD_FOR_OTHER_ADDRESS))
230 /* If we are going to reload an address, compute the reload type to
231 use. */
232 #define ADDR_TYPE(type) \
233 ((type) == RELOAD_FOR_INPUT_ADDRESS \
234 ? RELOAD_FOR_INPADDR_ADDRESS \
235 : ((type) == RELOAD_FOR_OUTPUT_ADDRESS \
236 ? RELOAD_FOR_OUTADDR_ADDRESS \
237 : (type)))
239 #ifdef HAVE_SECONDARY_RELOADS
240 static int push_secondary_reload PROTO((int, rtx, int, int, enum reg_class,
241 enum machine_mode, enum reload_type,
242 enum insn_code *));
243 #endif
244 static enum reg_class find_valid_class PROTO((enum machine_mode, int));
245 static int push_reload PROTO((rtx, rtx, rtx *, rtx *, enum reg_class,
246 enum machine_mode, enum machine_mode,
247 int, int, int, enum reload_type));
248 static void push_replacement PROTO((rtx *, int, enum machine_mode));
249 static void combine_reloads PROTO((void));
250 static int find_reusable_reload PROTO((rtx *, rtx, enum reg_class,
251 enum reload_type, int, int));
252 static rtx find_dummy_reload PROTO((rtx, rtx, rtx *, rtx *,
253 enum machine_mode, enum machine_mode,
254 enum reg_class, int, int));
255 static int earlyclobber_operand_p PROTO((rtx));
256 static int hard_reg_set_here_p PROTO((int, int, rtx));
257 static struct decomposition decompose PROTO((rtx));
258 static int immune_p PROTO((rtx, rtx, struct decomposition));
259 static int alternative_allows_memconst PROTO((const char *, int));
260 static rtx find_reloads_toplev PROTO((rtx, int, enum reload_type, int, int, rtx));
261 static rtx make_memloc PROTO((rtx, int));
262 static int find_reloads_address PROTO((enum machine_mode, rtx *, rtx, rtx *,
263 int, enum reload_type, int, rtx));
264 static rtx subst_reg_equivs PROTO((rtx, rtx));
265 static rtx subst_indexed_address PROTO((rtx));
266 static int find_reloads_address_1 PROTO((enum machine_mode, rtx, int, rtx *,
267 int, enum reload_type,int, rtx));
268 static void find_reloads_address_part PROTO((rtx, rtx *, enum reg_class,
269 enum machine_mode, int,
270 enum reload_type, int));
271 static rtx find_reloads_subreg_address PROTO((rtx, int, int, enum reload_type,
272 int, rtx));
273 static int find_inc_amount PROTO((rtx, rtx));
274 static int loc_mentioned_in_p PROTO((rtx *, rtx));
276 #ifdef HAVE_SECONDARY_RELOADS
278 /* Determine if any secondary reloads are needed for loading (if IN_P is
279 non-zero) or storing (if IN_P is zero) X to or from a reload register of
280 register class RELOAD_CLASS in mode RELOAD_MODE. If secondary reloads
281 are needed, push them.
283 Return the reload number of the secondary reload we made, or -1 if
284 we didn't need one. *PICODE is set to the insn_code to use if we do
285 need a secondary reload. */
287 static int
288 push_secondary_reload (in_p, x, opnum, optional, reload_class, reload_mode,
289 type, picode)
290 int in_p;
291 rtx x;
292 int opnum;
293 int optional;
294 enum reg_class reload_class;
295 enum machine_mode reload_mode;
296 enum reload_type type;
297 enum insn_code *picode;
299 enum reg_class class = NO_REGS;
300 enum machine_mode mode = reload_mode;
301 enum insn_code icode = CODE_FOR_nothing;
302 enum reg_class t_class = NO_REGS;
303 enum machine_mode t_mode = VOIDmode;
304 enum insn_code t_icode = CODE_FOR_nothing;
305 enum reload_type secondary_type;
306 int s_reload, t_reload = -1;
308 if (type == RELOAD_FOR_INPUT_ADDRESS
309 || type == RELOAD_FOR_OUTPUT_ADDRESS
310 || type == RELOAD_FOR_INPADDR_ADDRESS
311 || type == RELOAD_FOR_OUTADDR_ADDRESS)
312 secondary_type = type;
313 else
314 secondary_type = in_p ? RELOAD_FOR_INPUT_ADDRESS : RELOAD_FOR_OUTPUT_ADDRESS;
316 *picode = CODE_FOR_nothing;
318 /* If X is a paradoxical SUBREG, use the inner value to determine both the
319 mode and object being reloaded. */
320 if (GET_CODE (x) == SUBREG
321 && (GET_MODE_SIZE (GET_MODE (x))
322 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))))
324 x = SUBREG_REG (x);
325 reload_mode = GET_MODE (x);
328 /* If X is a pseudo-register that has an equivalent MEM (actually, if it
329 is still a pseudo-register by now, it *must* have an equivalent MEM
330 but we don't want to assume that), use that equivalent when seeing if
331 a secondary reload is needed since whether or not a reload is needed
332 might be sensitive to the form of the MEM. */
334 if (GET_CODE (x) == REG && REGNO (x) >= FIRST_PSEUDO_REGISTER
335 && reg_equiv_mem[REGNO (x)] != 0)
336 x = reg_equiv_mem[REGNO (x)];
338 #ifdef SECONDARY_INPUT_RELOAD_CLASS
339 if (in_p)
340 class = SECONDARY_INPUT_RELOAD_CLASS (reload_class, reload_mode, x);
341 #endif
343 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
344 if (! in_p)
345 class = SECONDARY_OUTPUT_RELOAD_CLASS (reload_class, reload_mode, x);
346 #endif
348 /* If we don't need any secondary registers, done. */
349 if (class == NO_REGS)
350 return -1;
352 /* Get a possible insn to use. If the predicate doesn't accept X, don't
353 use the insn. */
355 icode = (in_p ? reload_in_optab[(int) reload_mode]
356 : reload_out_optab[(int) reload_mode]);
358 if (icode != CODE_FOR_nothing
359 && insn_data[(int) icode].operand[in_p].predicate
360 && (! (insn_data[(int) icode].operand[in_p].predicate) (x, reload_mode)))
361 icode = CODE_FOR_nothing;
363 /* If we will be using an insn, see if it can directly handle the reload
364 register we will be using. If it can, the secondary reload is for a
365 scratch register. If it can't, we will use the secondary reload for
366 an intermediate register and require a tertiary reload for the scratch
367 register. */
369 if (icode != CODE_FOR_nothing)
371 /* If IN_P is non-zero, the reload register will be the output in
372 operand 0. If IN_P is zero, the reload register will be the input
373 in operand 1. Outputs should have an initial "=", which we must
374 skip. */
376 char insn_letter
377 = insn_data[(int) icode].operand[!in_p].constraint[in_p];
378 enum reg_class insn_class
379 = (insn_letter == 'r' ? GENERAL_REGS
380 : REG_CLASS_FROM_LETTER ((unsigned char) insn_letter));
382 if (insn_class == NO_REGS
383 || (in_p
384 && insn_data[(int) icode].operand[!in_p].constraint[0] != '=')
385 /* The scratch register's constraint must start with "=&". */
386 || insn_data[(int) icode].operand[2].constraint[0] != '='
387 || insn_data[(int) icode].operand[2].constraint[1] != '&')
388 abort ();
390 if (reg_class_subset_p (reload_class, insn_class))
391 mode = insn_data[(int) icode].operand[2].mode;
392 else
394 char t_letter = insn_data[(int) icode].operand[2].constraint[2];
395 class = insn_class;
396 t_mode = insn_data[(int) icode].operand[2].mode;
397 t_class = (t_letter == 'r' ? GENERAL_REGS
398 : REG_CLASS_FROM_LETTER ((unsigned char) t_letter));
399 t_icode = icode;
400 icode = CODE_FOR_nothing;
404 /* This case isn't valid, so fail. Reload is allowed to use the same
405 register for RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT reloads, but
406 in the case of a secondary register, we actually need two different
407 registers for correct code. We fail here to prevent the possibility of
408 silently generating incorrect code later.
410 The convention is that secondary input reloads are valid only if the
411 secondary_class is different from class. If you have such a case, you
412 can not use secondary reloads, you must work around the problem some
413 other way.
415 Allow this when MODE is not reload_mode and assume that the generated
416 code handles this case (it does on the Alpha, which is the only place
417 this currently happens). */
419 if (in_p && class == reload_class && mode == reload_mode)
420 abort ();
422 /* If we need a tertiary reload, see if we have one we can reuse or else
423 make a new one. */
425 if (t_class != NO_REGS)
427 for (t_reload = 0; t_reload < n_reloads; t_reload++)
428 if (rld[t_reload].secondary_p
429 && (reg_class_subset_p (t_class, rld[t_reload].class)
430 || reg_class_subset_p (rld[t_reload].class, t_class))
431 && ((in_p && rld[t_reload].inmode == t_mode)
432 || (! in_p && rld[t_reload].outmode == t_mode))
433 && ((in_p && (rld[t_reload].secondary_in_icode
434 == CODE_FOR_nothing))
435 || (! in_p &&(rld[t_reload].secondary_out_icode
436 == CODE_FOR_nothing)))
437 && (reg_class_size[(int) t_class] == 1 || SMALL_REGISTER_CLASSES)
438 && MERGABLE_RELOADS (secondary_type,
439 rld[t_reload].when_needed,
440 opnum, rld[t_reload].opnum))
442 if (in_p)
443 rld[t_reload].inmode = t_mode;
444 if (! in_p)
445 rld[t_reload].outmode = t_mode;
447 if (reg_class_subset_p (t_class, rld[t_reload].class))
448 rld[t_reload].class = t_class;
450 rld[t_reload].opnum = MIN (rld[t_reload].opnum, opnum);
451 rld[t_reload].optional &= optional;
452 rld[t_reload].secondary_p = 1;
453 if (MERGE_TO_OTHER (secondary_type, rld[t_reload].when_needed,
454 opnum, rld[t_reload].opnum))
455 rld[t_reload].when_needed = RELOAD_OTHER;
458 if (t_reload == n_reloads)
460 /* We need to make a new tertiary reload for this register class. */
461 rld[t_reload].in = rld[t_reload].out = 0;
462 rld[t_reload].class = t_class;
463 rld[t_reload].inmode = in_p ? t_mode : VOIDmode;
464 rld[t_reload].outmode = ! in_p ? t_mode : VOIDmode;
465 rld[t_reload].reg_rtx = 0;
466 rld[t_reload].optional = optional;
467 rld[t_reload].nongroup = 0;
468 rld[t_reload].inc = 0;
469 /* Maybe we could combine these, but it seems too tricky. */
470 rld[t_reload].nocombine = 1;
471 rld[t_reload].in_reg = 0;
472 rld[t_reload].out_reg = 0;
473 rld[t_reload].opnum = opnum;
474 rld[t_reload].when_needed = secondary_type;
475 rld[t_reload].secondary_in_reload = -1;
476 rld[t_reload].secondary_out_reload = -1;
477 rld[t_reload].secondary_in_icode = CODE_FOR_nothing;
478 rld[t_reload].secondary_out_icode = CODE_FOR_nothing;
479 rld[t_reload].secondary_p = 1;
481 n_reloads++;
485 /* See if we can reuse an existing secondary reload. */
486 for (s_reload = 0; s_reload < n_reloads; s_reload++)
487 if (rld[s_reload].secondary_p
488 && (reg_class_subset_p (class, rld[s_reload].class)
489 || reg_class_subset_p (rld[s_reload].class, class))
490 && ((in_p && rld[s_reload].inmode == mode)
491 || (! in_p && rld[s_reload].outmode == mode))
492 && ((in_p && rld[s_reload].secondary_in_reload == t_reload)
493 || (! in_p && rld[s_reload].secondary_out_reload == t_reload))
494 && ((in_p && rld[s_reload].secondary_in_icode == t_icode)
495 || (! in_p && rld[s_reload].secondary_out_icode == t_icode))
496 && (reg_class_size[(int) class] == 1 || SMALL_REGISTER_CLASSES)
497 && MERGABLE_RELOADS (secondary_type, rld[s_reload].when_needed,
498 opnum, rld[s_reload].opnum))
500 if (in_p)
501 rld[s_reload].inmode = mode;
502 if (! in_p)
503 rld[s_reload].outmode = mode;
505 if (reg_class_subset_p (class, rld[s_reload].class))
506 rld[s_reload].class = class;
508 rld[s_reload].opnum = MIN (rld[s_reload].opnum, opnum);
509 rld[s_reload].optional &= optional;
510 rld[s_reload].secondary_p = 1;
511 if (MERGE_TO_OTHER (secondary_type, rld[s_reload].when_needed,
512 opnum, rld[s_reload].opnum))
513 rld[s_reload].when_needed = RELOAD_OTHER;
516 if (s_reload == n_reloads)
518 #ifdef SECONDARY_MEMORY_NEEDED
519 /* If we need a memory location to copy between the two reload regs,
520 set it up now. Note that we do the input case before making
521 the reload and the output case after. This is due to the
522 way reloads are output. */
524 if (in_p && icode == CODE_FOR_nothing
525 && SECONDARY_MEMORY_NEEDED (class, reload_class, mode))
526 get_secondary_mem (x, reload_mode, opnum, type);
527 #endif
529 /* We need to make a new secondary reload for this register class. */
530 rld[s_reload].in = rld[s_reload].out = 0;
531 rld[s_reload].class = class;
533 rld[s_reload].inmode = in_p ? mode : VOIDmode;
534 rld[s_reload].outmode = ! in_p ? mode : VOIDmode;
535 rld[s_reload].reg_rtx = 0;
536 rld[s_reload].optional = optional;
537 rld[s_reload].nongroup = 0;
538 rld[s_reload].inc = 0;
539 /* Maybe we could combine these, but it seems too tricky. */
540 rld[s_reload].nocombine = 1;
541 rld[s_reload].in_reg = 0;
542 rld[s_reload].out_reg = 0;
543 rld[s_reload].opnum = opnum;
544 rld[s_reload].when_needed = secondary_type;
545 rld[s_reload].secondary_in_reload = in_p ? t_reload : -1;
546 rld[s_reload].secondary_out_reload = ! in_p ? t_reload : -1;
547 rld[s_reload].secondary_in_icode = in_p ? t_icode : CODE_FOR_nothing;
548 rld[s_reload].secondary_out_icode
549 = ! in_p ? t_icode : CODE_FOR_nothing;
550 rld[s_reload].secondary_p = 1;
552 n_reloads++;
554 #ifdef SECONDARY_MEMORY_NEEDED
555 if (! in_p && icode == CODE_FOR_nothing
556 && SECONDARY_MEMORY_NEEDED (reload_class, class, mode))
557 get_secondary_mem (x, mode, opnum, type);
558 #endif
561 *picode = icode;
562 return s_reload;
564 #endif /* HAVE_SECONDARY_RELOADS */
566 #ifdef SECONDARY_MEMORY_NEEDED
568 /* Return a memory location that will be used to copy X in mode MODE.
569 If we haven't already made a location for this mode in this insn,
570 call find_reloads_address on the location being returned. */
573 get_secondary_mem (x, mode, opnum, type)
574 rtx x;
575 enum machine_mode mode;
576 int opnum;
577 enum reload_type type;
579 rtx loc;
580 int mem_valid;
582 /* By default, if MODE is narrower than a word, widen it to a word.
583 This is required because most machines that require these memory
584 locations do not support short load and stores from all registers
585 (e.g., FP registers). */
587 #ifdef SECONDARY_MEMORY_NEEDED_MODE
588 mode = SECONDARY_MEMORY_NEEDED_MODE (mode);
589 #else
590 if (GET_MODE_BITSIZE (mode) < BITS_PER_WORD)
591 mode = mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (mode), 0);
592 #endif
594 /* If we already have made a MEM for this operand in MODE, return it. */
595 if (secondary_memlocs_elim[(int) mode][opnum] != 0)
596 return secondary_memlocs_elim[(int) mode][opnum];
598 /* If this is the first time we've tried to get a MEM for this mode,
599 allocate a new one. `something_changed' in reload will get set
600 by noticing that the frame size has changed. */
602 if (secondary_memlocs[(int) mode] == 0)
604 #ifdef SECONDARY_MEMORY_NEEDED_RTX
605 secondary_memlocs[(int) mode] = SECONDARY_MEMORY_NEEDED_RTX (mode);
606 #else
607 secondary_memlocs[(int) mode]
608 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
609 #endif
612 /* Get a version of the address doing any eliminations needed. If that
613 didn't give us a new MEM, make a new one if it isn't valid. */
615 loc = eliminate_regs (secondary_memlocs[(int) mode], VOIDmode, NULL_RTX);
616 mem_valid = strict_memory_address_p (mode, XEXP (loc, 0));
618 if (! mem_valid && loc == secondary_memlocs[(int) mode])
619 loc = copy_rtx (loc);
621 /* The only time the call below will do anything is if the stack
622 offset is too large. In that case IND_LEVELS doesn't matter, so we
623 can just pass a zero. Adjust the type to be the address of the
624 corresponding object. If the address was valid, save the eliminated
625 address. If it wasn't valid, we need to make a reload each time, so
626 don't save it. */
628 if (! mem_valid)
630 type = (type == RELOAD_FOR_INPUT ? RELOAD_FOR_INPUT_ADDRESS
631 : type == RELOAD_FOR_OUTPUT ? RELOAD_FOR_OUTPUT_ADDRESS
632 : RELOAD_OTHER);
634 find_reloads_address (mode, NULL_PTR, XEXP (loc, 0), &XEXP (loc, 0),
635 opnum, type, 0, 0);
638 secondary_memlocs_elim[(int) mode][opnum] = loc;
639 return loc;
642 /* Clear any secondary memory locations we've made. */
644 void
645 clear_secondary_mem ()
647 bzero ((char *) secondary_memlocs, sizeof secondary_memlocs);
649 #endif /* SECONDARY_MEMORY_NEEDED */
651 /* Find the largest class for which every register number plus N is valid in
652 M1 (if in range). Abort if no such class exists. */
654 static enum reg_class
655 find_valid_class (m1, n)
656 enum machine_mode m1;
657 int n;
659 int class;
660 int regno;
661 enum reg_class best_class;
662 int best_size = 0;
664 for (class = 1; class < N_REG_CLASSES; class++)
666 int bad = 0;
667 for (regno = 0; regno < FIRST_PSEUDO_REGISTER && ! bad; regno++)
668 if (TEST_HARD_REG_BIT (reg_class_contents[class], regno)
669 && TEST_HARD_REG_BIT (reg_class_contents[class], regno + n)
670 && ! HARD_REGNO_MODE_OK (regno + n, m1))
671 bad = 1;
673 if (! bad && reg_class_size[class] > best_size)
674 best_class = class, best_size = reg_class_size[class];
677 if (best_size == 0)
678 abort ();
680 return best_class;
683 /* Return the number of a previously made reload that can be combined with
684 a new one, or n_reloads if none of the existing reloads can be used.
685 OUT, CLASS, TYPE and OPNUM are the same arguments as passed to
686 push_reload, they determine the kind of the new reload that we try to
687 combine. P_IN points to the corresponding value of IN, which can be
688 modified by this function.
689 DONT_SHARE is nonzero if we can't share any input-only reload for IN. */
690 static int
691 find_reusable_reload (p_in, out, class, type, opnum, dont_share)
692 rtx *p_in, out;
693 enum reg_class class;
694 enum reload_type type;
695 int opnum, dont_share;
697 rtx in = *p_in;
698 int i;
699 /* We can't merge two reloads if the output of either one is
700 earlyclobbered. */
702 if (earlyclobber_operand_p (out))
703 return n_reloads;
705 /* We can use an existing reload if the class is right
706 and at least one of IN and OUT is a match
707 and the other is at worst neutral.
708 (A zero compared against anything is neutral.)
710 If SMALL_REGISTER_CLASSES, don't use existing reloads unless they are
711 for the same thing since that can cause us to need more reload registers
712 than we otherwise would. */
714 for (i = 0; i < n_reloads; i++)
715 if ((reg_class_subset_p (class, rld[i].class)
716 || reg_class_subset_p (rld[i].class, class))
717 /* If the existing reload has a register, it must fit our class. */
718 && (rld[i].reg_rtx == 0
719 || TEST_HARD_REG_BIT (reg_class_contents[(int) class],
720 true_regnum (rld[i].reg_rtx)))
721 && ((in != 0 && MATCHES (rld[i].in, in) && ! dont_share
722 && (out == 0 || rld[i].out == 0 || MATCHES (rld[i].out, out)))
723 || (out != 0 && MATCHES (rld[i].out, out)
724 && (in == 0 || rld[i].in == 0 || MATCHES (rld[i].in, in))))
725 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
726 && (reg_class_size[(int) class] == 1 || SMALL_REGISTER_CLASSES)
727 && MERGABLE_RELOADS (type, rld[i].when_needed, opnum, rld[i].opnum))
728 return i;
730 /* Reloading a plain reg for input can match a reload to postincrement
731 that reg, since the postincrement's value is the right value.
732 Likewise, it can match a preincrement reload, since we regard
733 the preincrementation as happening before any ref in this insn
734 to that register. */
735 for (i = 0; i < n_reloads; i++)
736 if ((reg_class_subset_p (class, rld[i].class)
737 || reg_class_subset_p (rld[i].class, class))
738 /* If the existing reload has a register, it must fit our
739 class. */
740 && (rld[i].reg_rtx == 0
741 || TEST_HARD_REG_BIT (reg_class_contents[(int) class],
742 true_regnum (rld[i].reg_rtx)))
743 && out == 0 && rld[i].out == 0 && rld[i].in != 0
744 && ((GET_CODE (in) == REG
745 && (GET_CODE (rld[i].in) == POST_INC
746 || GET_CODE (rld[i].in) == POST_DEC
747 || GET_CODE (rld[i].in) == PRE_INC
748 || GET_CODE (rld[i].in) == PRE_DEC)
749 && MATCHES (XEXP (rld[i].in, 0), in))
751 (GET_CODE (rld[i].in) == REG
752 && (GET_CODE (in) == POST_INC
753 || GET_CODE (in) == POST_DEC
754 || GET_CODE (in) == PRE_INC
755 || GET_CODE (in) == PRE_DEC)
756 && MATCHES (XEXP (in, 0), rld[i].in)))
757 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
758 && (reg_class_size[(int) class] == 1 || SMALL_REGISTER_CLASSES)
759 && MERGABLE_RELOADS (type, rld[i].when_needed,
760 opnum, rld[i].opnum))
762 /* Make sure reload_in ultimately has the increment,
763 not the plain register. */
764 if (GET_CODE (in) == REG)
765 *p_in = rld[i].in;
766 return i;
768 return n_reloads;
771 /* Record one reload that needs to be performed.
772 IN is an rtx saying where the data are to be found before this instruction.
773 OUT says where they must be stored after the instruction.
774 (IN is zero for data not read, and OUT is zero for data not written.)
775 INLOC and OUTLOC point to the places in the instructions where
776 IN and OUT were found.
777 If IN and OUT are both non-zero, it means the same register must be used
778 to reload both IN and OUT.
780 CLASS is a register class required for the reloaded data.
781 INMODE is the machine mode that the instruction requires
782 for the reg that replaces IN and OUTMODE is likewise for OUT.
784 If IN is zero, then OUT's location and mode should be passed as
785 INLOC and INMODE.
787 STRICT_LOW is the 1 if there is a containing STRICT_LOW_PART rtx.
789 OPTIONAL nonzero means this reload does not need to be performed:
790 it can be discarded if that is more convenient.
792 OPNUM and TYPE say what the purpose of this reload is.
794 The return value is the reload-number for this reload.
796 If both IN and OUT are nonzero, in some rare cases we might
797 want to make two separate reloads. (Actually we never do this now.)
798 Therefore, the reload-number for OUT is stored in
799 output_reloadnum when we return; the return value applies to IN.
800 Usually (presently always), when IN and OUT are nonzero,
801 the two reload-numbers are equal, but the caller should be careful to
802 distinguish them. */
804 static int
805 push_reload (in, out, inloc, outloc, class,
806 inmode, outmode, strict_low, optional, opnum, type)
807 rtx in, out;
808 rtx *inloc, *outloc;
809 enum reg_class class;
810 enum machine_mode inmode, outmode;
811 int strict_low;
812 int optional;
813 int opnum;
814 enum reload_type type;
816 register int i;
817 int dont_share = 0;
818 int dont_remove_subreg = 0;
819 rtx *in_subreg_loc = 0, *out_subreg_loc = 0;
820 int secondary_in_reload = -1, secondary_out_reload = -1;
821 enum insn_code secondary_in_icode = CODE_FOR_nothing;
822 enum insn_code secondary_out_icode = CODE_FOR_nothing;
824 /* INMODE and/or OUTMODE could be VOIDmode if no mode
825 has been specified for the operand. In that case,
826 use the operand's mode as the mode to reload. */
827 if (inmode == VOIDmode && in != 0)
828 inmode = GET_MODE (in);
829 if (outmode == VOIDmode && out != 0)
830 outmode = GET_MODE (out);
832 /* If IN is a pseudo register everywhere-equivalent to a constant, and
833 it is not in a hard register, reload straight from the constant,
834 since we want to get rid of such pseudo registers.
835 Often this is done earlier, but not always in find_reloads_address. */
836 if (in != 0 && GET_CODE (in) == REG)
838 register int regno = REGNO (in);
840 if (regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
841 && reg_equiv_constant[regno] != 0)
842 in = reg_equiv_constant[regno];
845 /* Likewise for OUT. Of course, OUT will never be equivalent to
846 an actual constant, but it might be equivalent to a memory location
847 (in the case of a parameter). */
848 if (out != 0 && GET_CODE (out) == REG)
850 register int regno = REGNO (out);
852 if (regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
853 && reg_equiv_constant[regno] != 0)
854 out = reg_equiv_constant[regno];
857 /* If we have a read-write operand with an address side-effect,
858 change either IN or OUT so the side-effect happens only once. */
859 if (in != 0 && out != 0 && GET_CODE (in) == MEM && rtx_equal_p (in, out))
861 if (GET_CODE (XEXP (in, 0)) == POST_INC
862 || GET_CODE (XEXP (in, 0)) == POST_DEC)
863 in = gen_rtx_MEM (GET_MODE (in), XEXP (XEXP (in, 0), 0));
864 if (GET_CODE (XEXP (in, 0)) == PRE_INC
865 || GET_CODE (XEXP (in, 0)) == PRE_DEC)
866 out = gen_rtx_MEM (GET_MODE (out), XEXP (XEXP (out, 0), 0));
869 /* If we are reloading a (SUBREG constant ...), really reload just the
870 inside expression in its own mode. Similarly for (SUBREG (PLUS ...)).
871 If we have (SUBREG:M1 (MEM:M2 ...) ...) (or an inner REG that is still
872 a pseudo and hence will become a MEM) with M1 wider than M2 and the
873 register is a pseudo, also reload the inside expression.
874 For machines that extend byte loads, do this for any SUBREG of a pseudo
875 where both M1 and M2 are a word or smaller, M1 is wider than M2, and
876 M2 is an integral mode that gets extended when loaded.
877 Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
878 either M1 is not valid for R or M2 is wider than a word but we only
879 need one word to store an M2-sized quantity in R.
880 (However, if OUT is nonzero, we need to reload the reg *and*
881 the subreg, so do nothing here, and let following statement handle it.)
883 Note that the case of (SUBREG (CONST_INT...)...) is handled elsewhere;
884 we can't handle it here because CONST_INT does not indicate a mode.
886 Similarly, we must reload the inside expression if we have a
887 STRICT_LOW_PART (presumably, in == out in the cas).
889 Also reload the inner expression if it does not require a secondary
890 reload but the SUBREG does.
892 Finally, reload the inner expression if it is a register that is in
893 the class whose registers cannot be referenced in a different size
894 and M1 is not the same size as M2. If SUBREG_WORD is nonzero, we
895 cannot reload just the inside since we might end up with the wrong
896 register class. But if it is inside a STRICT_LOW_PART, we have
897 no choice, so we hope we do get the right register class there. */
899 if (in != 0 && GET_CODE (in) == SUBREG
900 && (SUBREG_WORD (in) == 0 || strict_low)
901 #ifdef CLASS_CANNOT_CHANGE_SIZE
902 && class != CLASS_CANNOT_CHANGE_SIZE
903 #endif
904 && (CONSTANT_P (SUBREG_REG (in))
905 || GET_CODE (SUBREG_REG (in)) == PLUS
906 || strict_low
907 || (((GET_CODE (SUBREG_REG (in)) == REG
908 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER)
909 || GET_CODE (SUBREG_REG (in)) == MEM)
910 && ((GET_MODE_SIZE (inmode)
911 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
912 #ifdef LOAD_EXTEND_OP
913 || (GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
914 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
915 <= UNITS_PER_WORD)
916 && (GET_MODE_SIZE (inmode)
917 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
918 && INTEGRAL_MODE_P (GET_MODE (SUBREG_REG (in)))
919 && LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (in))) != NIL)
920 #endif
921 #ifdef WORD_REGISTER_OPERATIONS
922 || ((GET_MODE_SIZE (inmode)
923 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
924 && ((GET_MODE_SIZE (inmode) - 1) / UNITS_PER_WORD ==
925 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))) - 1)
926 / UNITS_PER_WORD)))
927 #endif
929 || (GET_CODE (SUBREG_REG (in)) == REG
930 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
931 /* The case where out is nonzero
932 is handled differently in the following statement. */
933 && (out == 0 || SUBREG_WORD (in) == 0)
934 && ((GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
935 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
936 > UNITS_PER_WORD)
937 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
938 / UNITS_PER_WORD)
939 != HARD_REGNO_NREGS (REGNO (SUBREG_REG (in)),
940 GET_MODE (SUBREG_REG (in)))))
941 || ! HARD_REGNO_MODE_OK ((REGNO (SUBREG_REG (in))
942 + SUBREG_WORD (in)),
943 inmode)))
944 #ifdef SECONDARY_INPUT_RELOAD_CLASS
945 || (SECONDARY_INPUT_RELOAD_CLASS (class, inmode, in) != NO_REGS
946 && (SECONDARY_INPUT_RELOAD_CLASS (class,
947 GET_MODE (SUBREG_REG (in)),
948 SUBREG_REG (in))
949 == NO_REGS))
950 #endif
951 #ifdef CLASS_CANNOT_CHANGE_SIZE
952 || (GET_CODE (SUBREG_REG (in)) == REG
953 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
954 && (TEST_HARD_REG_BIT
955 (reg_class_contents[(int) CLASS_CANNOT_CHANGE_SIZE],
956 REGNO (SUBREG_REG (in))))
957 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
958 != GET_MODE_SIZE (inmode)))
959 #endif
962 in_subreg_loc = inloc;
963 inloc = &SUBREG_REG (in);
964 in = *inloc;
965 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
966 if (GET_CODE (in) == MEM)
967 /* This is supposed to happen only for paradoxical subregs made by
968 combine.c. (SUBREG (MEM)) isn't supposed to occur other ways. */
969 if (GET_MODE_SIZE (GET_MODE (in)) > GET_MODE_SIZE (inmode))
970 abort ();
971 #endif
972 inmode = GET_MODE (in);
975 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
976 either M1 is not valid for R or M2 is wider than a word but we only
977 need one word to store an M2-sized quantity in R.
979 However, we must reload the inner reg *as well as* the subreg in
980 that case. */
982 /* Similar issue for (SUBREG constant ...) if it was not handled by the
983 code above. This can happen if SUBREG_WORD != 0. */
985 if (in != 0 && GET_CODE (in) == SUBREG
986 && (CONSTANT_P (SUBREG_REG (in))
987 || (GET_CODE (SUBREG_REG (in)) == REG
988 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
989 && (! HARD_REGNO_MODE_OK (REGNO (SUBREG_REG (in))
990 + SUBREG_WORD (in),
991 inmode)
992 || (GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
993 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
994 > UNITS_PER_WORD)
995 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
996 / UNITS_PER_WORD)
997 != HARD_REGNO_NREGS (REGNO (SUBREG_REG (in)),
998 GET_MODE (SUBREG_REG (in)))))))))
1000 /* This relies on the fact that emit_reload_insns outputs the
1001 instructions for input reloads of type RELOAD_OTHER in the same
1002 order as the reloads. Thus if the outer reload is also of type
1003 RELOAD_OTHER, we are guaranteed that this inner reload will be
1004 output before the outer reload. */
1005 push_reload (SUBREG_REG (in), NULL_RTX, &SUBREG_REG (in), NULL_PTR,
1006 find_valid_class (inmode, SUBREG_WORD (in)),
1007 VOIDmode, VOIDmode, 0, 0, opnum, type);
1008 dont_remove_subreg = 1;
1011 /* Similarly for paradoxical and problematical SUBREGs on the output.
1012 Note that there is no reason we need worry about the previous value
1013 of SUBREG_REG (out); even if wider than out,
1014 storing in a subreg is entitled to clobber it all
1015 (except in the case of STRICT_LOW_PART,
1016 and in that case the constraint should label it input-output.) */
1017 if (out != 0 && GET_CODE (out) == SUBREG
1018 && (SUBREG_WORD (out) == 0 || strict_low)
1019 #ifdef CLASS_CANNOT_CHANGE_SIZE
1020 && class != CLASS_CANNOT_CHANGE_SIZE
1021 #endif
1022 && (CONSTANT_P (SUBREG_REG (out))
1023 || strict_low
1024 || (((GET_CODE (SUBREG_REG (out)) == REG
1025 && REGNO (SUBREG_REG (out)) >= FIRST_PSEUDO_REGISTER)
1026 || GET_CODE (SUBREG_REG (out)) == MEM)
1027 && ((GET_MODE_SIZE (outmode)
1028 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1029 #ifdef WORD_REGISTER_OPERATIONS
1030 || ((GET_MODE_SIZE (outmode)
1031 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1032 && ((GET_MODE_SIZE (outmode) - 1) / UNITS_PER_WORD ==
1033 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))) - 1)
1034 / UNITS_PER_WORD)))
1035 #endif
1037 || (GET_CODE (SUBREG_REG (out)) == REG
1038 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1039 && ((GET_MODE_SIZE (outmode) <= UNITS_PER_WORD
1040 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1041 > UNITS_PER_WORD)
1042 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1043 / UNITS_PER_WORD)
1044 != HARD_REGNO_NREGS (REGNO (SUBREG_REG (out)),
1045 GET_MODE (SUBREG_REG (out)))))
1046 || ! HARD_REGNO_MODE_OK ((REGNO (SUBREG_REG (out))
1047 + SUBREG_WORD (out)),
1048 outmode)))
1049 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
1050 || (SECONDARY_OUTPUT_RELOAD_CLASS (class, outmode, out) != NO_REGS
1051 && (SECONDARY_OUTPUT_RELOAD_CLASS (class,
1052 GET_MODE (SUBREG_REG (out)),
1053 SUBREG_REG (out))
1054 == NO_REGS))
1055 #endif
1056 #ifdef CLASS_CANNOT_CHANGE_SIZE
1057 || (GET_CODE (SUBREG_REG (out)) == REG
1058 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1059 && (TEST_HARD_REG_BIT
1060 (reg_class_contents[(int) CLASS_CANNOT_CHANGE_SIZE],
1061 REGNO (SUBREG_REG (out))))
1062 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1063 != GET_MODE_SIZE (outmode)))
1064 #endif
1067 out_subreg_loc = outloc;
1068 outloc = &SUBREG_REG (out);
1069 out = *outloc;
1070 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
1071 if (GET_CODE (out) == MEM
1072 && GET_MODE_SIZE (GET_MODE (out)) > GET_MODE_SIZE (outmode))
1073 abort ();
1074 #endif
1075 outmode = GET_MODE (out);
1078 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
1079 either M1 is not valid for R or M2 is wider than a word but we only
1080 need one word to store an M2-sized quantity in R.
1082 However, we must reload the inner reg *as well as* the subreg in
1083 that case. In this case, the inner reg is an in-out reload. */
1085 if (out != 0 && GET_CODE (out) == SUBREG
1086 && GET_CODE (SUBREG_REG (out)) == REG
1087 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1088 && (! HARD_REGNO_MODE_OK (REGNO (SUBREG_REG (out)) + SUBREG_WORD (out),
1089 outmode)
1090 || (GET_MODE_SIZE (outmode) <= UNITS_PER_WORD
1091 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1092 > UNITS_PER_WORD)
1093 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1094 / UNITS_PER_WORD)
1095 != HARD_REGNO_NREGS (REGNO (SUBREG_REG (out)),
1096 GET_MODE (SUBREG_REG (out)))))))
1098 /* This relies on the fact that emit_reload_insns outputs the
1099 instructions for output reloads of type RELOAD_OTHER in reverse
1100 order of the reloads. Thus if the outer reload is also of type
1101 RELOAD_OTHER, we are guaranteed that this inner reload will be
1102 output after the outer reload. */
1103 dont_remove_subreg = 1;
1104 push_reload (SUBREG_REG (out), SUBREG_REG (out), &SUBREG_REG (out),
1105 &SUBREG_REG (out),
1106 find_valid_class (outmode, SUBREG_WORD (out)),
1107 VOIDmode, VOIDmode, 0, 0,
1108 opnum, RELOAD_OTHER);
1111 /* If IN appears in OUT, we can't share any input-only reload for IN. */
1112 if (in != 0 && out != 0 && GET_CODE (out) == MEM
1113 && (GET_CODE (in) == REG || GET_CODE (in) == MEM)
1114 && reg_overlap_mentioned_for_reload_p (in, XEXP (out, 0)))
1115 dont_share = 1;
1117 /* If IN is a SUBREG of a hard register, make a new REG. This
1118 simplifies some of the cases below. */
1120 if (in != 0 && GET_CODE (in) == SUBREG && GET_CODE (SUBREG_REG (in)) == REG
1121 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1122 && ! dont_remove_subreg)
1123 in = gen_rtx_REG (GET_MODE (in),
1124 REGNO (SUBREG_REG (in)) + SUBREG_WORD (in));
1126 /* Similarly for OUT. */
1127 if (out != 0 && GET_CODE (out) == SUBREG
1128 && GET_CODE (SUBREG_REG (out)) == REG
1129 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1130 && ! dont_remove_subreg)
1131 out = gen_rtx_REG (GET_MODE (out),
1132 REGNO (SUBREG_REG (out)) + SUBREG_WORD (out));
1134 /* Narrow down the class of register wanted if that is
1135 desirable on this machine for efficiency. */
1136 if (in != 0)
1137 class = PREFERRED_RELOAD_CLASS (in, class);
1139 /* Output reloads may need analogous treatment, different in detail. */
1140 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1141 if (out != 0)
1142 class = PREFERRED_OUTPUT_RELOAD_CLASS (out, class);
1143 #endif
1145 /* Make sure we use a class that can handle the actual pseudo
1146 inside any subreg. For example, on the 386, QImode regs
1147 can appear within SImode subregs. Although GENERAL_REGS
1148 can handle SImode, QImode needs a smaller class. */
1149 #ifdef LIMIT_RELOAD_CLASS
1150 if (in_subreg_loc)
1151 class = LIMIT_RELOAD_CLASS (inmode, class);
1152 else if (in != 0 && GET_CODE (in) == SUBREG)
1153 class = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (in)), class);
1155 if (out_subreg_loc)
1156 class = LIMIT_RELOAD_CLASS (outmode, class);
1157 if (out != 0 && GET_CODE (out) == SUBREG)
1158 class = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (out)), class);
1159 #endif
1161 /* Verify that this class is at least possible for the mode that
1162 is specified. */
1163 if (this_insn_is_asm)
1165 enum machine_mode mode;
1166 if (GET_MODE_SIZE (inmode) > GET_MODE_SIZE (outmode))
1167 mode = inmode;
1168 else
1169 mode = outmode;
1170 if (mode == VOIDmode)
1172 error_for_asm (this_insn, "cannot reload integer constant operand in `asm'");
1173 mode = word_mode;
1174 if (in != 0)
1175 inmode = word_mode;
1176 if (out != 0)
1177 outmode = word_mode;
1179 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1180 if (HARD_REGNO_MODE_OK (i, mode)
1181 && TEST_HARD_REG_BIT (reg_class_contents[(int) class], i))
1183 int nregs = HARD_REGNO_NREGS (i, mode);
1185 int j;
1186 for (j = 1; j < nregs; j++)
1187 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) class], i + j))
1188 break;
1189 if (j == nregs)
1190 break;
1192 if (i == FIRST_PSEUDO_REGISTER)
1194 error_for_asm (this_insn, "impossible register constraint in `asm'");
1195 class = ALL_REGS;
1199 /* Optional output reloads are always OK even if we have no register class,
1200 since the function of these reloads is only to have spill_reg_store etc.
1201 set, so that the storing insn can be deleted later. */
1202 if (class == NO_REGS
1203 && (optional == 0 || type != RELOAD_FOR_OUTPUT))
1204 abort ();
1206 i = find_reusable_reload (&in, out, class, type, opnum, dont_share);
1208 if (i == n_reloads)
1210 /* See if we need a secondary reload register to move between CLASS
1211 and IN or CLASS and OUT. Get the icode and push any required reloads
1212 needed for each of them if so. */
1214 #ifdef SECONDARY_INPUT_RELOAD_CLASS
1215 if (in != 0)
1216 secondary_in_reload
1217 = push_secondary_reload (1, in, opnum, optional, class, inmode, type,
1218 &secondary_in_icode);
1219 #endif
1221 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
1222 if (out != 0 && GET_CODE (out) != SCRATCH)
1223 secondary_out_reload
1224 = push_secondary_reload (0, out, opnum, optional, class, outmode,
1225 type, &secondary_out_icode);
1226 #endif
1228 /* We found no existing reload suitable for re-use.
1229 So add an additional reload. */
1231 #ifdef SECONDARY_MEMORY_NEEDED
1232 /* If a memory location is needed for the copy, make one. */
1233 if (in != 0 && GET_CODE (in) == REG
1234 && REGNO (in) < FIRST_PSEUDO_REGISTER
1235 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (REGNO (in)),
1236 class, inmode))
1237 get_secondary_mem (in, inmode, opnum, type);
1238 #endif
1240 i = n_reloads;
1241 rld[i].in = in;
1242 rld[i].out = out;
1243 rld[i].class = class;
1244 rld[i].inmode = inmode;
1245 rld[i].outmode = outmode;
1246 rld[i].reg_rtx = 0;
1247 rld[i].optional = optional;
1248 rld[i].nongroup = 0;
1249 rld[i].inc = 0;
1250 rld[i].nocombine = 0;
1251 rld[i].in_reg = inloc ? *inloc : 0;
1252 rld[i].out_reg = outloc ? *outloc : 0;
1253 rld[i].opnum = opnum;
1254 rld[i].when_needed = type;
1255 rld[i].secondary_in_reload = secondary_in_reload;
1256 rld[i].secondary_out_reload = secondary_out_reload;
1257 rld[i].secondary_in_icode = secondary_in_icode;
1258 rld[i].secondary_out_icode = secondary_out_icode;
1259 rld[i].secondary_p = 0;
1261 n_reloads++;
1263 #ifdef SECONDARY_MEMORY_NEEDED
1264 if (out != 0 && GET_CODE (out) == REG
1265 && REGNO (out) < FIRST_PSEUDO_REGISTER
1266 && SECONDARY_MEMORY_NEEDED (class, REGNO_REG_CLASS (REGNO (out)),
1267 outmode))
1268 get_secondary_mem (out, outmode, opnum, type);
1269 #endif
1271 else
1273 /* We are reusing an existing reload,
1274 but we may have additional information for it.
1275 For example, we may now have both IN and OUT
1276 while the old one may have just one of them. */
1278 /* The modes can be different. If they are, we want to reload in
1279 the larger mode, so that the value is valid for both modes. */
1280 if (inmode != VOIDmode
1281 && GET_MODE_SIZE (inmode) > GET_MODE_SIZE (rld[i].inmode))
1282 rld[i].inmode = inmode;
1283 if (outmode != VOIDmode
1284 && GET_MODE_SIZE (outmode) > GET_MODE_SIZE (rld[i].outmode))
1285 rld[i].outmode = outmode;
1286 if (in != 0)
1288 rtx in_reg = inloc ? *inloc : 0;
1289 /* If we merge reloads for two distinct rtl expressions that
1290 are identical in content, there might be duplicate address
1291 reloads. Remove the extra set now, so that if we later find
1292 that we can inherit this reload, we can get rid of the
1293 address reloads altogether.
1295 Do not do this if both reloads are optional since the result
1296 would be an optional reload which could potentially leave
1297 unresolved address replacements.
1299 It is not sufficient to call transfer_replacements since
1300 choose_reload_regs will remove the replacements for address
1301 reloads of inherited reloads which results in the same
1302 problem. */
1303 if (rld[i].in != in && rtx_equal_p (in, rld[i].in)
1304 && ! (rld[i].optional && optional))
1306 /* We must keep the address reload with the lower operand
1307 number alive. */
1308 if (opnum > rld[i].opnum)
1310 remove_address_replacements (in);
1311 in = rld[i].in;
1312 in_reg = rld[i].in_reg;
1314 else
1315 remove_address_replacements (rld[i].in);
1317 rld[i].in = in;
1318 rld[i].in_reg = in_reg;
1320 if (out != 0)
1322 rld[i].out = out;
1323 rld[i].out_reg = outloc ? *outloc : 0;
1325 if (reg_class_subset_p (class, rld[i].class))
1326 rld[i].class = class;
1327 rld[i].optional &= optional;
1328 if (MERGE_TO_OTHER (type, rld[i].when_needed,
1329 opnum, rld[i].opnum))
1330 rld[i].when_needed = RELOAD_OTHER;
1331 rld[i].opnum = MIN (rld[i].opnum, opnum);
1334 /* If the ostensible rtx being reload differs from the rtx found
1335 in the location to substitute, this reload is not safe to combine
1336 because we cannot reliably tell whether it appears in the insn. */
1338 if (in != 0 && in != *inloc)
1339 rld[i].nocombine = 1;
1341 #if 0
1342 /* This was replaced by changes in find_reloads_address_1 and the new
1343 function inc_for_reload, which go with a new meaning of reload_inc. */
1345 /* If this is an IN/OUT reload in an insn that sets the CC,
1346 it must be for an autoincrement. It doesn't work to store
1347 the incremented value after the insn because that would clobber the CC.
1348 So we must do the increment of the value reloaded from,
1349 increment it, store it back, then decrement again. */
1350 if (out != 0 && sets_cc0_p (PATTERN (this_insn)))
1352 out = 0;
1353 rld[i].out = 0;
1354 rld[i].inc = find_inc_amount (PATTERN (this_insn), in);
1355 /* If we did not find a nonzero amount-to-increment-by,
1356 that contradicts the belief that IN is being incremented
1357 in an address in this insn. */
1358 if (rld[i].inc == 0)
1359 abort ();
1361 #endif
1363 /* If we will replace IN and OUT with the reload-reg,
1364 record where they are located so that substitution need
1365 not do a tree walk. */
1367 if (replace_reloads)
1369 if (inloc != 0)
1371 register struct replacement *r = &replacements[n_replacements++];
1372 r->what = i;
1373 r->subreg_loc = in_subreg_loc;
1374 r->where = inloc;
1375 r->mode = inmode;
1377 if (outloc != 0 && outloc != inloc)
1379 register struct replacement *r = &replacements[n_replacements++];
1380 r->what = i;
1381 r->where = outloc;
1382 r->subreg_loc = out_subreg_loc;
1383 r->mode = outmode;
1387 /* If this reload is just being introduced and it has both
1388 an incoming quantity and an outgoing quantity that are
1389 supposed to be made to match, see if either one of the two
1390 can serve as the place to reload into.
1392 If one of them is acceptable, set rld[i].reg_rtx
1393 to that one. */
1395 if (in != 0 && out != 0 && in != out && rld[i].reg_rtx == 0)
1397 rld[i].reg_rtx = find_dummy_reload (in, out, inloc, outloc,
1398 inmode, outmode,
1399 rld[i].class, i,
1400 earlyclobber_operand_p (out));
1402 /* If the outgoing register already contains the same value
1403 as the incoming one, we can dispense with loading it.
1404 The easiest way to tell the caller that is to give a phony
1405 value for the incoming operand (same as outgoing one). */
1406 if (rld[i].reg_rtx == out
1407 && (GET_CODE (in) == REG || CONSTANT_P (in))
1408 && 0 != find_equiv_reg (in, this_insn, 0, REGNO (out),
1409 static_reload_reg_p, i, inmode))
1410 rld[i].in = out;
1413 /* If this is an input reload and the operand contains a register that
1414 dies in this insn and is used nowhere else, see if it is the right class
1415 to be used for this reload. Use it if so. (This occurs most commonly
1416 in the case of paradoxical SUBREGs and in-out reloads). We cannot do
1417 this if it is also an output reload that mentions the register unless
1418 the output is a SUBREG that clobbers an entire register.
1420 Note that the operand might be one of the spill regs, if it is a
1421 pseudo reg and we are in a block where spilling has not taken place.
1422 But if there is no spilling in this block, that is OK.
1423 An explicitly used hard reg cannot be a spill reg. */
1425 if (rld[i].reg_rtx == 0 && in != 0)
1427 rtx note;
1428 int regno;
1430 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1431 if (REG_NOTE_KIND (note) == REG_DEAD
1432 && GET_CODE (XEXP (note, 0)) == REG
1433 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1434 && reg_mentioned_p (XEXP (note, 0), in)
1435 && ! refers_to_regno_for_reload_p (regno,
1436 (regno
1437 + HARD_REGNO_NREGS (regno,
1438 inmode)),
1439 PATTERN (this_insn), inloc)
1440 /* If this is also an output reload, IN cannot be used as
1441 the reload register if it is set in this insn unless IN
1442 is also OUT. */
1443 && (out == 0 || in == out
1444 || ! hard_reg_set_here_p (regno,
1445 (regno
1446 + HARD_REGNO_NREGS (regno,
1447 inmode)),
1448 PATTERN (this_insn)))
1449 /* ??? Why is this code so different from the previous?
1450 Is there any simple coherent way to describe the two together?
1451 What's going on here. */
1452 && (in != out
1453 || (GET_CODE (in) == SUBREG
1454 && (((GET_MODE_SIZE (GET_MODE (in)) + (UNITS_PER_WORD - 1))
1455 / UNITS_PER_WORD)
1456 == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1457 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
1458 /* Make sure the operand fits in the reg that dies. */
1459 && GET_MODE_SIZE (inmode) <= GET_MODE_SIZE (GET_MODE (XEXP (note, 0)))
1460 && HARD_REGNO_MODE_OK (regno, inmode)
1461 && GET_MODE_SIZE (outmode) <= GET_MODE_SIZE (GET_MODE (XEXP (note, 0)))
1462 && HARD_REGNO_MODE_OK (regno, outmode)
1463 && TEST_HARD_REG_BIT (reg_class_contents[(int) class], regno)
1464 && !fixed_regs[regno])
1466 rld[i].reg_rtx = gen_rtx_REG (inmode, regno);
1467 break;
1471 if (out)
1472 output_reloadnum = i;
1474 return i;
1477 /* Record an additional place we must replace a value
1478 for which we have already recorded a reload.
1479 RELOADNUM is the value returned by push_reload
1480 when the reload was recorded.
1481 This is used in insn patterns that use match_dup. */
1483 static void
1484 push_replacement (loc, reloadnum, mode)
1485 rtx *loc;
1486 int reloadnum;
1487 enum machine_mode mode;
1489 if (replace_reloads)
1491 register struct replacement *r = &replacements[n_replacements++];
1492 r->what = reloadnum;
1493 r->where = loc;
1494 r->subreg_loc = 0;
1495 r->mode = mode;
1499 /* Transfer all replacements that used to be in reload FROM to be in
1500 reload TO. */
1502 void
1503 transfer_replacements (to, from)
1504 int to, from;
1506 int i;
1508 for (i = 0; i < n_replacements; i++)
1509 if (replacements[i].what == from)
1510 replacements[i].what = to;
1513 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1514 or a subpart of it. If we have any replacements registered for IN_RTX,
1515 cancel the reloads that were supposed to load them.
1516 Return non-zero if we canceled any reloads. */
1518 remove_address_replacements (in_rtx)
1519 rtx in_rtx;
1521 int i, j;
1522 char reload_flags[MAX_RELOADS];
1523 int something_changed = 0;
1525 bzero (reload_flags, sizeof reload_flags);
1526 for (i = 0, j = 0; i < n_replacements; i++)
1528 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1529 reload_flags[replacements[i].what] |= 1;
1530 else
1532 replacements[j++] = replacements[i];
1533 reload_flags[replacements[i].what] |= 2;
1536 /* Note that the following store must be done before the recursive calls. */
1537 n_replacements = j;
1539 for (i = n_reloads - 1; i >= 0; i--)
1541 if (reload_flags[i] == 1)
1543 deallocate_reload_reg (i);
1544 remove_address_replacements (rld[i].in);
1545 rld[i].in = 0;
1546 something_changed = 1;
1549 return something_changed;
1552 /* Return non-zero if IN contains a piece of rtl that has the address LOC */
1553 static int
1554 loc_mentioned_in_p (loc, in)
1555 rtx *loc, in;
1557 enum rtx_code code = GET_CODE (in);
1558 const char *fmt = GET_RTX_FORMAT (code);
1559 int i, j;
1561 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1563 if (loc == &in->fld[i].rtx)
1564 return 1;
1565 if (fmt[i] == 'e')
1567 if (loc_mentioned_in_p (loc, XEXP (in, i)))
1568 return 1;
1570 else if (fmt[i] == 'E')
1571 for (j = XVECLEN (in, i) - 1; i >= 0; i--)
1572 if (loc_mentioned_in_p (loc, XVECEXP (in, i, j)))
1573 return 1;
1575 return 0;
1578 /* If there is only one output reload, and it is not for an earlyclobber
1579 operand, try to combine it with a (logically unrelated) input reload
1580 to reduce the number of reload registers needed.
1582 This is safe if the input reload does not appear in
1583 the value being output-reloaded, because this implies
1584 it is not needed any more once the original insn completes.
1586 If that doesn't work, see we can use any of the registers that
1587 die in this insn as a reload register. We can if it is of the right
1588 class and does not appear in the value being output-reloaded. */
1590 static void
1591 combine_reloads ()
1593 int i;
1594 int output_reload = -1;
1595 int secondary_out = -1;
1596 rtx note;
1598 /* Find the output reload; return unless there is exactly one
1599 and that one is mandatory. */
1601 for (i = 0; i < n_reloads; i++)
1602 if (rld[i].out != 0)
1604 if (output_reload >= 0)
1605 return;
1606 output_reload = i;
1609 if (output_reload < 0 || rld[output_reload].optional)
1610 return;
1612 /* An input-output reload isn't combinable. */
1614 if (rld[output_reload].in != 0)
1615 return;
1617 /* If this reload is for an earlyclobber operand, we can't do anything. */
1618 if (earlyclobber_operand_p (rld[output_reload].out))
1619 return;
1621 /* Check each input reload; can we combine it? */
1623 for (i = 0; i < n_reloads; i++)
1624 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1625 /* Life span of this reload must not extend past main insn. */
1626 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1627 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1628 && rld[i].when_needed != RELOAD_OTHER
1629 && (CLASS_MAX_NREGS (rld[i].class, rld[i].inmode)
1630 == CLASS_MAX_NREGS (rld[output_reload].class,
1631 rld[output_reload].outmode))
1632 && rld[i].inc == 0
1633 && rld[i].reg_rtx == 0
1634 #ifdef SECONDARY_MEMORY_NEEDED
1635 /* Don't combine two reloads with different secondary
1636 memory locations. */
1637 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1638 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1639 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1640 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1641 #endif
1642 && (SMALL_REGISTER_CLASSES
1643 ? (rld[i].class == rld[output_reload].class)
1644 : (reg_class_subset_p (rld[i].class,
1645 rld[output_reload].class)
1646 || reg_class_subset_p (rld[output_reload].class,
1647 rld[i].class)))
1648 && (MATCHES (rld[i].in, rld[output_reload].out)
1649 /* Args reversed because the first arg seems to be
1650 the one that we imagine being modified
1651 while the second is the one that might be affected. */
1652 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1653 rld[i].in)
1654 /* However, if the input is a register that appears inside
1655 the output, then we also can't share.
1656 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1657 If the same reload reg is used for both reg 69 and the
1658 result to be stored in memory, then that result
1659 will clobber the address of the memory ref. */
1660 && ! (GET_CODE (rld[i].in) == REG
1661 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1662 rld[output_reload].out))))
1663 && (reg_class_size[(int) rld[i].class]
1664 || SMALL_REGISTER_CLASSES)
1665 /* We will allow making things slightly worse by combining an
1666 input and an output, but no worse than that. */
1667 && (rld[i].when_needed == RELOAD_FOR_INPUT
1668 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1670 int j;
1672 /* We have found a reload to combine with! */
1673 rld[i].out = rld[output_reload].out;
1674 rld[i].out_reg = rld[output_reload].out_reg;
1675 rld[i].outmode = rld[output_reload].outmode;
1676 /* Mark the old output reload as inoperative. */
1677 rld[output_reload].out = 0;
1678 /* The combined reload is needed for the entire insn. */
1679 rld[i].when_needed = RELOAD_OTHER;
1680 /* If the output reload had a secondary reload, copy it. */
1681 if (rld[output_reload].secondary_out_reload != -1)
1683 rld[i].secondary_out_reload
1684 = rld[output_reload].secondary_out_reload;
1685 rld[i].secondary_out_icode
1686 = rld[output_reload].secondary_out_icode;
1689 #ifdef SECONDARY_MEMORY_NEEDED
1690 /* Copy any secondary MEM. */
1691 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1692 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1693 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1694 #endif
1695 /* If required, minimize the register class. */
1696 if (reg_class_subset_p (rld[output_reload].class,
1697 rld[i].class))
1698 rld[i].class = rld[output_reload].class;
1700 /* Transfer all replacements from the old reload to the combined. */
1701 for (j = 0; j < n_replacements; j++)
1702 if (replacements[j].what == output_reload)
1703 replacements[j].what = i;
1705 return;
1708 /* If this insn has only one operand that is modified or written (assumed
1709 to be the first), it must be the one corresponding to this reload. It
1710 is safe to use anything that dies in this insn for that output provided
1711 that it does not occur in the output (we already know it isn't an
1712 earlyclobber. If this is an asm insn, give up. */
1714 if (INSN_CODE (this_insn) == -1)
1715 return;
1717 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1718 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1719 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1720 return;
1722 /* See if some hard register that dies in this insn and is not used in
1723 the output is the right class. Only works if the register we pick
1724 up can fully hold our output reload. */
1725 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1726 if (REG_NOTE_KIND (note) == REG_DEAD
1727 && GET_CODE (XEXP (note, 0)) == REG
1728 && ! reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1729 rld[output_reload].out)
1730 && REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1731 && HARD_REGNO_MODE_OK (REGNO (XEXP (note, 0)), rld[output_reload].outmode)
1732 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].class],
1733 REGNO (XEXP (note, 0)))
1734 && (HARD_REGNO_NREGS (REGNO (XEXP (note, 0)), rld[output_reload].outmode)
1735 <= HARD_REGNO_NREGS (REGNO (XEXP (note, 0)), GET_MODE (XEXP (note, 0))))
1736 /* Ensure that a secondary or tertiary reload for this output
1737 won't want this register. */
1738 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1739 || (! (TEST_HARD_REG_BIT
1740 (reg_class_contents[(int) rld[secondary_out].class],
1741 REGNO (XEXP (note, 0))))
1742 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1743 || ! (TEST_HARD_REG_BIT
1744 (reg_class_contents[(int) rld[secondary_out].class],
1745 REGNO (XEXP (note, 0)))))))
1746 && ! fixed_regs[REGNO (XEXP (note, 0))])
1748 rld[output_reload].reg_rtx
1749 = gen_rtx_REG (rld[output_reload].outmode,
1750 REGNO (XEXP (note, 0)));
1751 return;
1755 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1756 See if one of IN and OUT is a register that may be used;
1757 this is desirable since a spill-register won't be needed.
1758 If so, return the register rtx that proves acceptable.
1760 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1761 CLASS is the register class required for the reload.
1763 If FOR_REAL is >= 0, it is the number of the reload,
1764 and in some cases when it can be discovered that OUT doesn't need
1765 to be computed, clear out rld[FOR_REAL].out.
1767 If FOR_REAL is -1, this should not be done, because this call
1768 is just to see if a register can be found, not to find and install it.
1770 EARLYCLOBBER is non-zero if OUT is an earlyclobber operand. This
1771 puts an additional constraint on being able to use IN for OUT since
1772 IN must not appear elsewhere in the insn (it is assumed that IN itself
1773 is safe from the earlyclobber). */
1775 static rtx
1776 find_dummy_reload (real_in, real_out, inloc, outloc,
1777 inmode, outmode, class, for_real, earlyclobber)
1778 rtx real_in, real_out;
1779 rtx *inloc, *outloc;
1780 enum machine_mode inmode, outmode;
1781 enum reg_class class;
1782 int for_real;
1783 int earlyclobber;
1785 rtx in = real_in;
1786 rtx out = real_out;
1787 int in_offset = 0;
1788 int out_offset = 0;
1789 rtx value = 0;
1791 /* If operands exceed a word, we can't use either of them
1792 unless they have the same size. */
1793 if (GET_MODE_SIZE (outmode) != GET_MODE_SIZE (inmode)
1794 && (GET_MODE_SIZE (outmode) > UNITS_PER_WORD
1795 || GET_MODE_SIZE (inmode) > UNITS_PER_WORD))
1796 return 0;
1798 /* Find the inside of any subregs. */
1799 while (GET_CODE (out) == SUBREG)
1801 out_offset = SUBREG_WORD (out);
1802 out = SUBREG_REG (out);
1804 while (GET_CODE (in) == SUBREG)
1806 in_offset = SUBREG_WORD (in);
1807 in = SUBREG_REG (in);
1810 /* Narrow down the reg class, the same way push_reload will;
1811 otherwise we might find a dummy now, but push_reload won't. */
1812 class = PREFERRED_RELOAD_CLASS (in, class);
1814 /* See if OUT will do. */
1815 if (GET_CODE (out) == REG
1816 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1818 register int regno = REGNO (out) + out_offset;
1819 int nwords = HARD_REGNO_NREGS (regno, outmode);
1820 rtx saved_rtx;
1822 /* When we consider whether the insn uses OUT,
1823 ignore references within IN. They don't prevent us
1824 from copying IN into OUT, because those refs would
1825 move into the insn that reloads IN.
1827 However, we only ignore IN in its role as this reload.
1828 If the insn uses IN elsewhere and it contains OUT,
1829 that counts. We can't be sure it's the "same" operand
1830 so it might not go through this reload. */
1831 saved_rtx = *inloc;
1832 *inloc = const0_rtx;
1834 if (regno < FIRST_PSEUDO_REGISTER
1835 /* A fixed reg that can overlap other regs better not be used
1836 for reloading in any way. */
1837 #ifdef OVERLAPPING_REGNO_P
1838 && ! (fixed_regs[regno] && OVERLAPPING_REGNO_P (regno))
1839 #endif
1840 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
1841 PATTERN (this_insn), outloc))
1843 int i;
1844 for (i = 0; i < nwords; i++)
1845 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) class],
1846 regno + i))
1847 break;
1849 if (i == nwords)
1851 if (GET_CODE (real_out) == REG)
1852 value = real_out;
1853 else
1854 value = gen_rtx_REG (outmode, regno);
1858 *inloc = saved_rtx;
1861 /* Consider using IN if OUT was not acceptable
1862 or if OUT dies in this insn (like the quotient in a divmod insn).
1863 We can't use IN unless it is dies in this insn,
1864 which means we must know accurately which hard regs are live.
1865 Also, the result can't go in IN if IN is used within OUT,
1866 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
1867 if (hard_regs_live_known
1868 && GET_CODE (in) == REG
1869 && REGNO (in) < FIRST_PSEUDO_REGISTER
1870 && (value == 0
1871 || find_reg_note (this_insn, REG_UNUSED, real_out))
1872 && find_reg_note (this_insn, REG_DEAD, real_in)
1873 && !fixed_regs[REGNO (in)]
1874 && HARD_REGNO_MODE_OK (REGNO (in),
1875 /* The only case where out and real_out might
1876 have different modes is where real_out
1877 is a subreg, and in that case, out
1878 has a real mode. */
1879 (GET_MODE (out) != VOIDmode
1880 ? GET_MODE (out) : outmode)))
1882 register int regno = REGNO (in) + in_offset;
1883 int nwords = HARD_REGNO_NREGS (regno, inmode);
1885 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, NULL_PTR)
1886 && ! hard_reg_set_here_p (regno, regno + nwords,
1887 PATTERN (this_insn))
1888 && (! earlyclobber
1889 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
1890 PATTERN (this_insn), inloc)))
1892 int i;
1893 for (i = 0; i < nwords; i++)
1894 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) class],
1895 regno + i))
1896 break;
1898 if (i == nwords)
1900 /* If we were going to use OUT as the reload reg
1901 and changed our mind, it means OUT is a dummy that
1902 dies here. So don't bother copying value to it. */
1903 if (for_real >= 0 && value == real_out)
1904 rld[for_real].out = 0;
1905 if (GET_CODE (real_in) == REG)
1906 value = real_in;
1907 else
1908 value = gen_rtx_REG (inmode, regno);
1913 return value;
1916 /* This page contains subroutines used mainly for determining
1917 whether the IN or an OUT of a reload can serve as the
1918 reload register. */
1920 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
1922 static int
1923 earlyclobber_operand_p (x)
1924 rtx x;
1926 int i;
1928 for (i = 0; i < n_earlyclobbers; i++)
1929 if (reload_earlyclobbers[i] == x)
1930 return 1;
1932 return 0;
1935 /* Return 1 if expression X alters a hard reg in the range
1936 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
1937 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
1938 X should be the body of an instruction. */
1940 static int
1941 hard_reg_set_here_p (beg_regno, end_regno, x)
1942 register int beg_regno, end_regno;
1943 rtx x;
1945 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
1947 register rtx op0 = SET_DEST (x);
1948 while (GET_CODE (op0) == SUBREG)
1949 op0 = SUBREG_REG (op0);
1950 if (GET_CODE (op0) == REG)
1952 register int r = REGNO (op0);
1953 /* See if this reg overlaps range under consideration. */
1954 if (r < end_regno
1955 && r + HARD_REGNO_NREGS (r, GET_MODE (op0)) > beg_regno)
1956 return 1;
1959 else if (GET_CODE (x) == PARALLEL)
1961 register int i = XVECLEN (x, 0) - 1;
1962 for (; i >= 0; i--)
1963 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
1964 return 1;
1967 return 0;
1970 /* Return 1 if ADDR is a valid memory address for mode MODE,
1971 and check that each pseudo reg has the proper kind of
1972 hard reg. */
1975 strict_memory_address_p (mode, addr)
1976 enum machine_mode mode;
1977 register rtx addr;
1979 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
1980 return 0;
1982 win:
1983 return 1;
1986 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
1987 if they are the same hard reg, and has special hacks for
1988 autoincrement and autodecrement.
1989 This is specifically intended for find_reloads to use
1990 in determining whether two operands match.
1991 X is the operand whose number is the lower of the two.
1993 The value is 2 if Y contains a pre-increment that matches
1994 a non-incrementing address in X. */
1996 /* ??? To be completely correct, we should arrange to pass
1997 for X the output operand and for Y the input operand.
1998 For now, we assume that the output operand has the lower number
1999 because that is natural in (SET output (... input ...)). */
2002 operands_match_p (x, y)
2003 register rtx x, y;
2005 register int i;
2006 register RTX_CODE code = GET_CODE (x);
2007 register const char *fmt;
2008 int success_2;
2010 if (x == y)
2011 return 1;
2012 if ((code == REG || (code == SUBREG && GET_CODE (SUBREG_REG (x)) == REG))
2013 && (GET_CODE (y) == REG || (GET_CODE (y) == SUBREG
2014 && GET_CODE (SUBREG_REG (y)) == REG)))
2016 register int j;
2018 if (code == SUBREG)
2020 i = REGNO (SUBREG_REG (x));
2021 if (i >= FIRST_PSEUDO_REGISTER)
2022 goto slow;
2023 i += SUBREG_WORD (x);
2025 else
2026 i = REGNO (x);
2028 if (GET_CODE (y) == SUBREG)
2030 j = REGNO (SUBREG_REG (y));
2031 if (j >= FIRST_PSEUDO_REGISTER)
2032 goto slow;
2033 j += SUBREG_WORD (y);
2035 else
2036 j = REGNO (y);
2038 /* On a WORDS_BIG_ENDIAN machine, point to the last register of a
2039 multiple hard register group, so that for example (reg:DI 0) and
2040 (reg:SI 1) will be considered the same register. */
2041 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
2042 && i < FIRST_PSEUDO_REGISTER)
2043 i += (GET_MODE_SIZE (GET_MODE (x)) / UNITS_PER_WORD) - 1;
2044 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (y)) > UNITS_PER_WORD
2045 && j < FIRST_PSEUDO_REGISTER)
2046 j += (GET_MODE_SIZE (GET_MODE (y)) / UNITS_PER_WORD) - 1;
2048 return i == j;
2050 /* If two operands must match, because they are really a single
2051 operand of an assembler insn, then two postincrements are invalid
2052 because the assembler insn would increment only once.
2053 On the other hand, an postincrement matches ordinary indexing
2054 if the postincrement is the output operand. */
2055 if (code == POST_DEC || code == POST_INC)
2056 return operands_match_p (XEXP (x, 0), y);
2057 /* Two preincrements are invalid
2058 because the assembler insn would increment only once.
2059 On the other hand, an preincrement matches ordinary indexing
2060 if the preincrement is the input operand.
2061 In this case, return 2, since some callers need to do special
2062 things when this happens. */
2063 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC)
2064 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2066 slow:
2068 /* Now we have disposed of all the cases
2069 in which different rtx codes can match. */
2070 if (code != GET_CODE (y))
2071 return 0;
2072 if (code == LABEL_REF)
2073 return XEXP (x, 0) == XEXP (y, 0);
2074 if (code == SYMBOL_REF)
2075 return XSTR (x, 0) == XSTR (y, 0);
2077 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2079 if (GET_MODE (x) != GET_MODE (y))
2080 return 0;
2082 /* Compare the elements. If any pair of corresponding elements
2083 fail to match, return 0 for the whole things. */
2085 success_2 = 0;
2086 fmt = GET_RTX_FORMAT (code);
2087 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2089 int val, j;
2090 switch (fmt[i])
2092 case 'w':
2093 if (XWINT (x, i) != XWINT (y, i))
2094 return 0;
2095 break;
2097 case 'i':
2098 if (XINT (x, i) != XINT (y, i))
2099 return 0;
2100 break;
2102 case 'e':
2103 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2104 if (val == 0)
2105 return 0;
2106 /* If any subexpression returns 2,
2107 we should return 2 if we are successful. */
2108 if (val == 2)
2109 success_2 = 1;
2110 break;
2112 case '0':
2113 break;
2115 case 'E':
2116 if (XVECLEN (x, i) != XVECLEN (y, i))
2117 return 0;
2118 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2120 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2121 if (val == 0)
2122 return 0;
2123 if (val == 2)
2124 success_2 = 1;
2126 break;
2128 /* It is believed that rtx's at this level will never
2129 contain anything but integers and other rtx's,
2130 except for within LABEL_REFs and SYMBOL_REFs. */
2131 default:
2132 abort ();
2135 return 1 + success_2;
2138 /* Describe the range of registers or memory referenced by X.
2139 If X is a register, set REG_FLAG and put the first register
2140 number into START and the last plus one into END.
2141 If X is a memory reference, put a base address into BASE
2142 and a range of integer offsets into START and END.
2143 If X is pushing on the stack, we can assume it causes no trouble,
2144 so we set the SAFE field. */
2146 static struct decomposition
2147 decompose (x)
2148 rtx x;
2150 struct decomposition val;
2151 int all_const = 0;
2153 val.reg_flag = 0;
2154 val.safe = 0;
2155 val.base = 0;
2156 if (GET_CODE (x) == MEM)
2158 rtx base = NULL_RTX, offset = 0;
2159 rtx addr = XEXP (x, 0);
2161 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2162 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2164 val.base = XEXP (addr, 0);
2165 val.start = - GET_MODE_SIZE (GET_MODE (x));
2166 val.end = GET_MODE_SIZE (GET_MODE (x));
2167 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2168 return val;
2171 if (GET_CODE (addr) == CONST)
2173 addr = XEXP (addr, 0);
2174 all_const = 1;
2176 if (GET_CODE (addr) == PLUS)
2178 if (CONSTANT_P (XEXP (addr, 0)))
2180 base = XEXP (addr, 1);
2181 offset = XEXP (addr, 0);
2183 else if (CONSTANT_P (XEXP (addr, 1)))
2185 base = XEXP (addr, 0);
2186 offset = XEXP (addr, 1);
2190 if (offset == 0)
2192 base = addr;
2193 offset = const0_rtx;
2195 if (GET_CODE (offset) == CONST)
2196 offset = XEXP (offset, 0);
2197 if (GET_CODE (offset) == PLUS)
2199 if (GET_CODE (XEXP (offset, 0)) == CONST_INT)
2201 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2202 offset = XEXP (offset, 0);
2204 else if (GET_CODE (XEXP (offset, 1)) == CONST_INT)
2206 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2207 offset = XEXP (offset, 1);
2209 else
2211 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2212 offset = const0_rtx;
2215 else if (GET_CODE (offset) != CONST_INT)
2217 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2218 offset = const0_rtx;
2221 if (all_const && GET_CODE (base) == PLUS)
2222 base = gen_rtx_CONST (GET_MODE (base), base);
2224 if (GET_CODE (offset) != CONST_INT)
2225 abort ();
2227 val.start = INTVAL (offset);
2228 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2229 val.base = base;
2230 return val;
2232 else if (GET_CODE (x) == REG)
2234 val.reg_flag = 1;
2235 val.start = true_regnum (x);
2236 if (val.start < 0)
2238 /* A pseudo with no hard reg. */
2239 val.start = REGNO (x);
2240 val.end = val.start + 1;
2242 else
2243 /* A hard reg. */
2244 val.end = val.start + HARD_REGNO_NREGS (val.start, GET_MODE (x));
2246 else if (GET_CODE (x) == SUBREG)
2248 if (GET_CODE (SUBREG_REG (x)) != REG)
2249 /* This could be more precise, but it's good enough. */
2250 return decompose (SUBREG_REG (x));
2251 val.reg_flag = 1;
2252 val.start = true_regnum (x);
2253 if (val.start < 0)
2254 return decompose (SUBREG_REG (x));
2255 else
2256 /* A hard reg. */
2257 val.end = val.start + HARD_REGNO_NREGS (val.start, GET_MODE (x));
2259 else if (CONSTANT_P (x)
2260 /* This hasn't been assigned yet, so it can't conflict yet. */
2261 || GET_CODE (x) == SCRATCH)
2262 val.safe = 1;
2263 else
2264 abort ();
2265 return val;
2268 /* Return 1 if altering Y will not modify the value of X.
2269 Y is also described by YDATA, which should be decompose (Y). */
2271 static int
2272 immune_p (x, y, ydata)
2273 rtx x, y;
2274 struct decomposition ydata;
2276 struct decomposition xdata;
2278 if (ydata.reg_flag)
2279 return !refers_to_regno_for_reload_p (ydata.start, ydata.end, x, NULL_PTR);
2280 if (ydata.safe)
2281 return 1;
2283 if (GET_CODE (y) != MEM)
2284 abort ();
2285 /* If Y is memory and X is not, Y can't affect X. */
2286 if (GET_CODE (x) != MEM)
2287 return 1;
2289 xdata = decompose (x);
2291 if (! rtx_equal_p (xdata.base, ydata.base))
2293 /* If bases are distinct symbolic constants, there is no overlap. */
2294 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2295 return 1;
2296 /* Constants and stack slots never overlap. */
2297 if (CONSTANT_P (xdata.base)
2298 && (ydata.base == frame_pointer_rtx
2299 || ydata.base == hard_frame_pointer_rtx
2300 || ydata.base == stack_pointer_rtx))
2301 return 1;
2302 if (CONSTANT_P (ydata.base)
2303 && (xdata.base == frame_pointer_rtx
2304 || xdata.base == hard_frame_pointer_rtx
2305 || xdata.base == stack_pointer_rtx))
2306 return 1;
2307 /* If either base is variable, we don't know anything. */
2308 return 0;
2312 return (xdata.start >= ydata.end || ydata.start >= xdata.end);
2315 /* Similar, but calls decompose. */
2318 safe_from_earlyclobber (op, clobber)
2319 rtx op, clobber;
2321 struct decomposition early_data;
2323 early_data = decompose (clobber);
2324 return immune_p (op, clobber, early_data);
2327 /* Main entry point of this file: search the body of INSN
2328 for values that need reloading and record them with push_reload.
2329 REPLACE nonzero means record also where the values occur
2330 so that subst_reloads can be used.
2332 IND_LEVELS says how many levels of indirection are supported by this
2333 machine; a value of zero means that a memory reference is not a valid
2334 memory address.
2336 LIVE_KNOWN says we have valid information about which hard
2337 regs are live at each point in the program; this is true when
2338 we are called from global_alloc but false when stupid register
2339 allocation has been done.
2341 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2342 which is nonnegative if the reg has been commandeered for reloading into.
2343 It is copied into STATIC_RELOAD_REG_P and referenced from there
2344 by various subroutines.
2346 Return TRUE if some operands need to be changed, because of swapping
2347 commutative operands, reg_equiv_address substitution, or whatever. */
2350 find_reloads (insn, replace, ind_levels, live_known, reload_reg_p)
2351 rtx insn;
2352 int replace, ind_levels;
2353 int live_known;
2354 short *reload_reg_p;
2356 register int insn_code_number;
2357 register int i, j;
2358 int noperands;
2359 /* These start out as the constraints for the insn
2360 and they are chewed up as we consider alternatives. */
2361 char *constraints[MAX_RECOG_OPERANDS];
2362 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2363 a register. */
2364 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2365 char pref_or_nothing[MAX_RECOG_OPERANDS];
2366 /* Nonzero for a MEM operand whose entire address needs a reload. */
2367 int address_reloaded[MAX_RECOG_OPERANDS];
2368 /* Value of enum reload_type to use for operand. */
2369 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2370 /* Value of enum reload_type to use within address of operand. */
2371 enum reload_type address_type[MAX_RECOG_OPERANDS];
2372 /* Save the usage of each operand. */
2373 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2374 int no_input_reloads = 0, no_output_reloads = 0;
2375 int n_alternatives;
2376 int this_alternative[MAX_RECOG_OPERANDS];
2377 char this_alternative_win[MAX_RECOG_OPERANDS];
2378 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2379 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2380 int this_alternative_matches[MAX_RECOG_OPERANDS];
2381 int swapped;
2382 int goal_alternative[MAX_RECOG_OPERANDS];
2383 int this_alternative_number;
2384 int goal_alternative_number;
2385 int operand_reloadnum[MAX_RECOG_OPERANDS];
2386 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2387 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2388 char goal_alternative_win[MAX_RECOG_OPERANDS];
2389 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2390 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2391 int goal_alternative_swapped;
2392 int best;
2393 int commutative;
2394 int changed;
2395 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2396 rtx substed_operand[MAX_RECOG_OPERANDS];
2397 rtx body = PATTERN (insn);
2398 rtx set = single_set (insn);
2399 int goal_earlyclobber, this_earlyclobber;
2400 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
2401 int retval = 0;
2403 this_insn = insn;
2404 n_reloads = 0;
2405 n_replacements = 0;
2406 n_earlyclobbers = 0;
2407 replace_reloads = replace;
2408 hard_regs_live_known = live_known;
2409 static_reload_reg_p = reload_reg_p;
2411 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads;
2412 neither are insns that SET cc0. Insns that use CC0 are not allowed
2413 to have any input reloads. */
2414 if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == CALL_INSN)
2415 no_output_reloads = 1;
2417 #ifdef HAVE_cc0
2418 if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
2419 no_input_reloads = 1;
2420 if (reg_set_p (cc0_rtx, PATTERN (insn)))
2421 no_output_reloads = 1;
2422 #endif
2424 #ifdef SECONDARY_MEMORY_NEEDED
2425 /* The eliminated forms of any secondary memory locations are per-insn, so
2426 clear them out here. */
2428 bzero ((char *) secondary_memlocs_elim, sizeof secondary_memlocs_elim);
2429 #endif
2431 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2432 is cheap to move between them. If it is not, there may not be an insn
2433 to do the copy, so we may need a reload. */
2434 if (GET_CODE (body) == SET
2435 && GET_CODE (SET_DEST (body)) == REG
2436 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2437 && GET_CODE (SET_SRC (body)) == REG
2438 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2439 && REGISTER_MOVE_COST (REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2440 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2441 return 0;
2443 extract_insn (insn);
2445 noperands = reload_n_operands = recog_data.n_operands;
2446 n_alternatives = recog_data.n_alternatives;
2448 /* Just return "no reloads" if insn has no operands with constraints. */
2449 if (noperands == 0 || n_alternatives == 0)
2450 return 0;
2452 insn_code_number = INSN_CODE (insn);
2453 this_insn_is_asm = insn_code_number < 0;
2455 bcopy ((char *) recog_data.operand_mode, (char *) operand_mode,
2456 noperands * sizeof (enum machine_mode));
2457 bcopy ((char *) recog_data.constraints, (char *) constraints,
2458 noperands * sizeof (char *));
2460 commutative = -1;
2462 /* If we will need to know, later, whether some pair of operands
2463 are the same, we must compare them now and save the result.
2464 Reloading the base and index registers will clobber them
2465 and afterward they will fail to match. */
2467 for (i = 0; i < noperands; i++)
2469 register char *p;
2470 register int c;
2472 substed_operand[i] = recog_data.operand[i];
2473 p = constraints[i];
2475 modified[i] = RELOAD_READ;
2477 /* Scan this operand's constraint to see if it is an output operand,
2478 an in-out operand, is commutative, or should match another. */
2480 while ((c = *p++))
2482 if (c == '=')
2483 modified[i] = RELOAD_WRITE;
2484 else if (c == '+')
2485 modified[i] = RELOAD_READ_WRITE;
2486 else if (c == '%')
2488 /* The last operand should not be marked commutative. */
2489 if (i == noperands - 1)
2490 abort ();
2492 commutative = i;
2494 else if (c >= '0' && c <= '9')
2496 c -= '0';
2497 operands_match[c][i]
2498 = operands_match_p (recog_data.operand[c],
2499 recog_data.operand[i]);
2501 /* An operand may not match itself. */
2502 if (c == i)
2503 abort ();
2505 /* If C can be commuted with C+1, and C might need to match I,
2506 then C+1 might also need to match I. */
2507 if (commutative >= 0)
2509 if (c == commutative || c == commutative + 1)
2511 int other = c + (c == commutative ? 1 : -1);
2512 operands_match[other][i]
2513 = operands_match_p (recog_data.operand[other],
2514 recog_data.operand[i]);
2516 if (i == commutative || i == commutative + 1)
2518 int other = i + (i == commutative ? 1 : -1);
2519 operands_match[c][other]
2520 = operands_match_p (recog_data.operand[c],
2521 recog_data.operand[other]);
2523 /* Note that C is supposed to be less than I.
2524 No need to consider altering both C and I because in
2525 that case we would alter one into the other. */
2531 /* Examine each operand that is a memory reference or memory address
2532 and reload parts of the addresses into index registers.
2533 Also here any references to pseudo regs that didn't get hard regs
2534 but are equivalent to constants get replaced in the insn itself
2535 with those constants. Nobody will ever see them again.
2537 Finally, set up the preferred classes of each operand. */
2539 for (i = 0; i < noperands; i++)
2541 register RTX_CODE code = GET_CODE (recog_data.operand[i]);
2543 address_reloaded[i] = 0;
2544 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2545 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2546 : RELOAD_OTHER);
2547 address_type[i]
2548 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2549 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2550 : RELOAD_OTHER);
2552 if (*constraints[i] == 0)
2553 /* Ignore things like match_operator operands. */
2555 else if (constraints[i][0] == 'p')
2557 find_reloads_address (VOIDmode, NULL_PTR,
2558 recog_data.operand[i],
2559 recog_data.operand_loc[i],
2560 i, operand_type[i], ind_levels, insn);
2562 /* If we now have a simple operand where we used to have a
2563 PLUS or MULT, re-recognize and try again. */
2564 if ((GET_RTX_CLASS (GET_CODE (*recog_data.operand_loc[i])) == 'o'
2565 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2566 && (GET_CODE (recog_data.operand[i]) == MULT
2567 || GET_CODE (recog_data.operand[i]) == PLUS))
2569 INSN_CODE (insn) = -1;
2570 retval = find_reloads (insn, replace, ind_levels, live_known,
2571 reload_reg_p);
2572 return retval;
2575 recog_data.operand[i] = *recog_data.operand_loc[i];
2576 substed_operand[i] = recog_data.operand[i];
2578 else if (code == MEM)
2580 address_reloaded[i]
2581 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2582 recog_data.operand_loc[i],
2583 XEXP (recog_data.operand[i], 0),
2584 &XEXP (recog_data.operand[i], 0),
2585 i, address_type[i], ind_levels, insn);
2586 recog_data.operand[i] = *recog_data.operand_loc[i];
2587 substed_operand[i] = recog_data.operand[i];
2589 else if (code == SUBREG)
2591 rtx reg = SUBREG_REG (recog_data.operand[i]);
2592 rtx op
2593 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2594 ind_levels,
2595 set != 0
2596 && &SET_DEST (set) == recog_data.operand_loc[i],
2597 insn);
2599 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2600 that didn't get a hard register, emit a USE with a REG_EQUAL
2601 note in front so that we might inherit a previous, possibly
2602 wider reload. */
2604 if (replace
2605 && GET_CODE (op) == MEM
2606 && GET_CODE (reg) == REG
2607 && (GET_MODE_SIZE (GET_MODE (reg))
2608 >= GET_MODE_SIZE (GET_MODE (op))))
2609 REG_NOTES (emit_insn_before (gen_rtx_USE (VOIDmode, reg), insn))
2610 = gen_rtx_EXPR_LIST (REG_EQUAL,
2611 reg_equiv_memory_loc[REGNO (reg)], NULL_RTX);
2613 substed_operand[i] = recog_data.operand[i] = op;
2615 else if (code == PLUS || GET_RTX_CLASS (code) == '1')
2616 /* We can get a PLUS as an "operand" as a result of register
2617 elimination. See eliminate_regs and gen_reload. We handle
2618 a unary operator by reloading the operand. */
2619 substed_operand[i] = recog_data.operand[i]
2620 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2621 ind_levels, 0, insn);
2622 else if (code == REG)
2624 /* This is equivalent to calling find_reloads_toplev.
2625 The code is duplicated for speed.
2626 When we find a pseudo always equivalent to a constant,
2627 we replace it by the constant. We must be sure, however,
2628 that we don't try to replace it in the insn in which it
2629 is being set. */
2630 register int regno = REGNO (recog_data.operand[i]);
2631 if (reg_equiv_constant[regno] != 0
2632 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2634 /* Record the existing mode so that the check if constants are
2635 allowed will work when operand_mode isn't specified. */
2637 if (operand_mode[i] == VOIDmode)
2638 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2640 substed_operand[i] = recog_data.operand[i]
2641 = reg_equiv_constant[regno];
2643 if (reg_equiv_memory_loc[regno] != 0
2644 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
2645 /* We need not give a valid is_set_dest argument since the case
2646 of a constant equivalence was checked above. */
2647 substed_operand[i] = recog_data.operand[i]
2648 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2649 ind_levels, 0, insn);
2651 /* If the operand is still a register (we didn't replace it with an
2652 equivalent), get the preferred class to reload it into. */
2653 code = GET_CODE (recog_data.operand[i]);
2654 preferred_class[i]
2655 = ((code == REG && REGNO (recog_data.operand[i])
2656 >= FIRST_PSEUDO_REGISTER)
2657 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2658 : NO_REGS);
2659 pref_or_nothing[i]
2660 = (code == REG
2661 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2662 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2665 #ifdef HAVE_cc0
2666 /* If we made any reloads for addresses, see if they violate a
2667 "no input reloads" requirement for this insn. */
2668 if (no_input_reloads)
2669 for (i = 0; i < n_reloads; i++)
2670 if (rld[i].in != 0)
2671 abort ();
2672 #endif
2674 /* If this is simply a copy from operand 1 to operand 0, merge the
2675 preferred classes for the operands. */
2676 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2677 && recog_data.operand[1] == SET_SRC (set))
2679 preferred_class[0] = preferred_class[1]
2680 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2681 pref_or_nothing[0] |= pref_or_nothing[1];
2682 pref_or_nothing[1] |= pref_or_nothing[0];
2685 /* Now see what we need for pseudo-regs that didn't get hard regs
2686 or got the wrong kind of hard reg. For this, we must consider
2687 all the operands together against the register constraints. */
2689 best = MAX_RECOG_OPERANDS * 2 + 600;
2691 swapped = 0;
2692 goal_alternative_swapped = 0;
2693 try_swapped:
2695 /* The constraints are made of several alternatives.
2696 Each operand's constraint looks like foo,bar,... with commas
2697 separating the alternatives. The first alternatives for all
2698 operands go together, the second alternatives go together, etc.
2700 First loop over alternatives. */
2702 for (this_alternative_number = 0;
2703 this_alternative_number < n_alternatives;
2704 this_alternative_number++)
2706 /* Loop over operands for one constraint alternative. */
2707 /* LOSERS counts those that don't fit this alternative
2708 and would require loading. */
2709 int losers = 0;
2710 /* BAD is set to 1 if it some operand can't fit this alternative
2711 even after reloading. */
2712 int bad = 0;
2713 /* REJECT is a count of how undesirable this alternative says it is
2714 if any reloading is required. If the alternative matches exactly
2715 then REJECT is ignored, but otherwise it gets this much
2716 counted against it in addition to the reloading needed. Each
2717 ? counts three times here since we want the disparaging caused by
2718 a bad register class to only count 1/3 as much. */
2719 int reject = 0;
2721 this_earlyclobber = 0;
2723 for (i = 0; i < noperands; i++)
2725 register char *p = constraints[i];
2726 register int win = 0;
2727 /* 0 => this operand can be reloaded somehow for this alternative */
2728 int badop = 1;
2729 /* 0 => this operand can be reloaded if the alternative allows regs. */
2730 int winreg = 0;
2731 int c;
2732 register rtx operand = recog_data.operand[i];
2733 int offset = 0;
2734 /* Nonzero means this is a MEM that must be reloaded into a reg
2735 regardless of what the constraint says. */
2736 int force_reload = 0;
2737 int offmemok = 0;
2738 /* Nonzero if a constant forced into memory would be OK for this
2739 operand. */
2740 int constmemok = 0;
2741 int earlyclobber = 0;
2743 /* If the predicate accepts a unary operator, it means that
2744 we need to reload the operand, but do not do this for
2745 match_operator and friends. */
2746 if (GET_RTX_CLASS (GET_CODE (operand)) == '1' && *p != 0)
2747 operand = XEXP (operand, 0);
2749 /* If the operand is a SUBREG, extract
2750 the REG or MEM (or maybe even a constant) within.
2751 (Constants can occur as a result of reg_equiv_constant.) */
2753 while (GET_CODE (operand) == SUBREG)
2755 offset += SUBREG_WORD (operand);
2756 operand = SUBREG_REG (operand);
2757 /* Force reload if this is a constant or PLUS or if there may
2758 be a problem accessing OPERAND in the outer mode. */
2759 if (CONSTANT_P (operand)
2760 || GET_CODE (operand) == PLUS
2761 /* We must force a reload of paradoxical SUBREGs
2762 of a MEM because the alignment of the inner value
2763 may not be enough to do the outer reference. On
2764 big-endian machines, it may also reference outside
2765 the object.
2767 On machines that extend byte operations and we have a
2768 SUBREG where both the inner and outer modes are no wider
2769 than a word and the inner mode is narrower, is integral,
2770 and gets extended when loaded from memory, combine.c has
2771 made assumptions about the behavior of the machine in such
2772 register access. If the data is, in fact, in memory we
2773 must always load using the size assumed to be in the
2774 register and let the insn do the different-sized
2775 accesses.
2777 This is doubly true if WORD_REGISTER_OPERATIONS. In
2778 this case eliminate_regs has left non-paradoxical
2779 subregs for push_reloads to see. Make sure it does
2780 by forcing the reload.
2782 ??? When is it right at this stage to have a subreg
2783 of a mem that is _not_ to be handled specialy? IMO
2784 those should have been reduced to just a mem. */
2785 || ((GET_CODE (operand) == MEM
2786 || (GET_CODE (operand)== REG
2787 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
2788 #ifndef WORD_REGISTER_OPERATIONS
2789 && (((GET_MODE_BITSIZE (GET_MODE (operand))
2790 < BIGGEST_ALIGNMENT)
2791 && (GET_MODE_SIZE (operand_mode[i])
2792 > GET_MODE_SIZE (GET_MODE (operand))))
2793 || (GET_CODE (operand) == MEM && BYTES_BIG_ENDIAN)
2794 #ifdef LOAD_EXTEND_OP
2795 || (GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
2796 && (GET_MODE_SIZE (GET_MODE (operand))
2797 <= UNITS_PER_WORD)
2798 && (GET_MODE_SIZE (operand_mode[i])
2799 > GET_MODE_SIZE (GET_MODE (operand)))
2800 && INTEGRAL_MODE_P (GET_MODE (operand))
2801 && LOAD_EXTEND_OP (GET_MODE (operand)) != NIL)
2802 #endif
2804 #endif
2806 /* Subreg of a hard reg which can't handle the subreg's mode
2807 or which would handle that mode in the wrong number of
2808 registers for subregging to work. */
2809 || (GET_CODE (operand) == REG
2810 && REGNO (operand) < FIRST_PSEUDO_REGISTER
2811 && ((GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
2812 && (GET_MODE_SIZE (GET_MODE (operand))
2813 > UNITS_PER_WORD)
2814 && ((GET_MODE_SIZE (GET_MODE (operand))
2815 / UNITS_PER_WORD)
2816 != HARD_REGNO_NREGS (REGNO (operand),
2817 GET_MODE (operand))))
2818 || ! HARD_REGNO_MODE_OK (REGNO (operand) + offset,
2819 operand_mode[i]))))
2820 force_reload = 1;
2823 this_alternative[i] = (int) NO_REGS;
2824 this_alternative_win[i] = 0;
2825 this_alternative_offmemok[i] = 0;
2826 this_alternative_earlyclobber[i] = 0;
2827 this_alternative_matches[i] = -1;
2829 /* An empty constraint or empty alternative
2830 allows anything which matched the pattern. */
2831 if (*p == 0 || *p == ',')
2832 win = 1, badop = 0;
2834 /* Scan this alternative's specs for this operand;
2835 set WIN if the operand fits any letter in this alternative.
2836 Otherwise, clear BADOP if this operand could
2837 fit some letter after reloads,
2838 or set WINREG if this operand could fit after reloads
2839 provided the constraint allows some registers. */
2841 while (*p && (c = *p++) != ',')
2842 switch (c)
2844 case '=': case '+': case '*':
2845 break;
2847 case '%':
2848 /* The last operand should not be marked commutative. */
2849 if (i != noperands - 1)
2850 commutative = i;
2851 break;
2853 case '?':
2854 reject += 6;
2855 break;
2857 case '!':
2858 reject = 600;
2859 break;
2861 case '#':
2862 /* Ignore rest of this alternative as far as
2863 reloading is concerned. */
2864 while (*p && *p != ',') p++;
2865 break;
2867 case '0': case '1': case '2': case '3': case '4':
2868 case '5': case '6': case '7': case '8': case '9':
2870 c -= '0';
2871 this_alternative_matches[i] = c;
2872 /* We are supposed to match a previous operand.
2873 If we do, we win if that one did.
2874 If we do not, count both of the operands as losers.
2875 (This is too conservative, since most of the time
2876 only a single reload insn will be needed to make
2877 the two operands win. As a result, this alternative
2878 may be rejected when it is actually desirable.) */
2879 if ((swapped && (c != commutative || i != commutative + 1))
2880 /* If we are matching as if two operands were swapped,
2881 also pretend that operands_match had been computed
2882 with swapped.
2883 But if I is the second of those and C is the first,
2884 don't exchange them, because operands_match is valid
2885 only on one side of its diagonal. */
2886 ? (operands_match
2887 [(c == commutative || c == commutative + 1)
2888 ? 2*commutative + 1 - c : c]
2889 [(i == commutative || i == commutative + 1)
2890 ? 2*commutative + 1 - i : i])
2891 : operands_match[c][i])
2893 /* If we are matching a non-offsettable address where an
2894 offsettable address was expected, then we must reject
2895 this combination, because we can't reload it. */
2896 if (this_alternative_offmemok[c]
2897 && GET_CODE (recog_data.operand[c]) == MEM
2898 && this_alternative[c] == (int) NO_REGS
2899 && ! this_alternative_win[c])
2900 bad = 1;
2902 win = this_alternative_win[c];
2904 else
2906 /* Operands don't match. */
2907 rtx value;
2908 /* Retroactively mark the operand we had to match
2909 as a loser, if it wasn't already. */
2910 if (this_alternative_win[c])
2911 losers++;
2912 this_alternative_win[c] = 0;
2913 if (this_alternative[c] == (int) NO_REGS)
2914 bad = 1;
2915 /* But count the pair only once in the total badness of
2916 this alternative, if the pair can be a dummy reload. */
2917 value
2918 = find_dummy_reload (recog_data.operand[i],
2919 recog_data.operand[c],
2920 recog_data.operand_loc[i],
2921 recog_data.operand_loc[c],
2922 operand_mode[i], operand_mode[c],
2923 this_alternative[c], -1,
2924 this_alternative_earlyclobber[c]);
2926 if (value != 0)
2927 losers--;
2929 /* This can be fixed with reloads if the operand
2930 we are supposed to match can be fixed with reloads. */
2931 badop = 0;
2932 this_alternative[i] = this_alternative[c];
2934 /* If we have to reload this operand and some previous
2935 operand also had to match the same thing as this
2936 operand, we don't know how to do that. So reject this
2937 alternative. */
2938 if (! win || force_reload)
2939 for (j = 0; j < i; j++)
2940 if (this_alternative_matches[j]
2941 == this_alternative_matches[i])
2942 badop = 1;
2944 break;
2946 case 'p':
2947 /* All necessary reloads for an address_operand
2948 were handled in find_reloads_address. */
2949 this_alternative[i] = (int) BASE_REG_CLASS;
2950 win = 1;
2951 break;
2953 case 'm':
2954 if (force_reload)
2955 break;
2956 if (GET_CODE (operand) == MEM
2957 || (GET_CODE (operand) == REG
2958 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
2959 && reg_renumber[REGNO (operand)] < 0))
2960 win = 1;
2961 if (CONSTANT_P (operand)
2962 /* force_const_mem does not accept HIGH. */
2963 && GET_CODE (operand) != HIGH)
2964 badop = 0;
2965 constmemok = 1;
2966 break;
2968 case '<':
2969 if (GET_CODE (operand) == MEM
2970 && ! address_reloaded[i]
2971 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
2972 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
2973 win = 1;
2974 break;
2976 case '>':
2977 if (GET_CODE (operand) == MEM
2978 && ! address_reloaded[i]
2979 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
2980 || GET_CODE (XEXP (operand, 0)) == POST_INC))
2981 win = 1;
2982 break;
2984 /* Memory operand whose address is not offsettable. */
2985 case 'V':
2986 if (force_reload)
2987 break;
2988 if (GET_CODE (operand) == MEM
2989 && ! (ind_levels ? offsettable_memref_p (operand)
2990 : offsettable_nonstrict_memref_p (operand))
2991 /* Certain mem addresses will become offsettable
2992 after they themselves are reloaded. This is important;
2993 we don't want our own handling of unoffsettables
2994 to override the handling of reg_equiv_address. */
2995 && !(GET_CODE (XEXP (operand, 0)) == REG
2996 && (ind_levels == 0
2997 || reg_equiv_address[REGNO (XEXP (operand, 0))] != 0)))
2998 win = 1;
2999 break;
3001 /* Memory operand whose address is offsettable. */
3002 case 'o':
3003 if (force_reload)
3004 break;
3005 if ((GET_CODE (operand) == MEM
3006 /* If IND_LEVELS, find_reloads_address won't reload a
3007 pseudo that didn't get a hard reg, so we have to
3008 reject that case. */
3009 && ((ind_levels ? offsettable_memref_p (operand)
3010 : offsettable_nonstrict_memref_p (operand))
3011 /* A reloaded address is offsettable because it is now
3012 just a simple register indirect. */
3013 || address_reloaded[i]))
3014 || (GET_CODE (operand) == REG
3015 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3016 && reg_renumber[REGNO (operand)] < 0
3017 /* If reg_equiv_address is nonzero, we will be
3018 loading it into a register; hence it will be
3019 offsettable, but we cannot say that reg_equiv_mem
3020 is offsettable without checking. */
3021 && ((reg_equiv_mem[REGNO (operand)] != 0
3022 && offsettable_memref_p (reg_equiv_mem[REGNO (operand)]))
3023 || (reg_equiv_address[REGNO (operand)] != 0))))
3024 win = 1;
3025 /* force_const_mem does not accept HIGH. */
3026 if ((CONSTANT_P (operand) && GET_CODE (operand) != HIGH)
3027 || GET_CODE (operand) == MEM)
3028 badop = 0;
3029 constmemok = 1;
3030 offmemok = 1;
3031 break;
3033 case '&':
3034 /* Output operand that is stored before the need for the
3035 input operands (and their index registers) is over. */
3036 earlyclobber = 1, this_earlyclobber = 1;
3037 break;
3039 case 'E':
3040 #ifndef REAL_ARITHMETIC
3041 /* Match any floating double constant, but only if
3042 we can examine the bits of it reliably. */
3043 if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT
3044 || HOST_BITS_PER_WIDE_INT != BITS_PER_WORD)
3045 && GET_MODE (operand) != VOIDmode && ! flag_pretend_float)
3046 break;
3047 #endif
3048 if (GET_CODE (operand) == CONST_DOUBLE)
3049 win = 1;
3050 break;
3052 case 'F':
3053 if (GET_CODE (operand) == CONST_DOUBLE)
3054 win = 1;
3055 break;
3057 case 'G':
3058 case 'H':
3059 if (GET_CODE (operand) == CONST_DOUBLE
3060 && CONST_DOUBLE_OK_FOR_LETTER_P (operand, c))
3061 win = 1;
3062 break;
3064 case 's':
3065 if (GET_CODE (operand) == CONST_INT
3066 || (GET_CODE (operand) == CONST_DOUBLE
3067 && GET_MODE (operand) == VOIDmode))
3068 break;
3069 case 'i':
3070 if (CONSTANT_P (operand)
3071 #ifdef LEGITIMATE_PIC_OPERAND_P
3072 && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (operand))
3073 #endif
3075 win = 1;
3076 break;
3078 case 'n':
3079 if (GET_CODE (operand) == CONST_INT
3080 || (GET_CODE (operand) == CONST_DOUBLE
3081 && GET_MODE (operand) == VOIDmode))
3082 win = 1;
3083 break;
3085 case 'I':
3086 case 'J':
3087 case 'K':
3088 case 'L':
3089 case 'M':
3090 case 'N':
3091 case 'O':
3092 case 'P':
3093 if (GET_CODE (operand) == CONST_INT
3094 && CONST_OK_FOR_LETTER_P (INTVAL (operand), c))
3095 win = 1;
3096 break;
3098 case 'X':
3099 win = 1;
3100 break;
3102 case 'g':
3103 if (! force_reload
3104 /* A PLUS is never a valid operand, but reload can make
3105 it from a register when eliminating registers. */
3106 && GET_CODE (operand) != PLUS
3107 /* A SCRATCH is not a valid operand. */
3108 && GET_CODE (operand) != SCRATCH
3109 #ifdef LEGITIMATE_PIC_OPERAND_P
3110 && (! CONSTANT_P (operand)
3111 || ! flag_pic
3112 || LEGITIMATE_PIC_OPERAND_P (operand))
3113 #endif
3114 && (GENERAL_REGS == ALL_REGS
3115 || GET_CODE (operand) != REG
3116 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3117 && reg_renumber[REGNO (operand)] < 0)))
3118 win = 1;
3119 /* Drop through into 'r' case */
3121 case 'r':
3122 this_alternative[i]
3123 = (int) reg_class_subunion[this_alternative[i]][(int) GENERAL_REGS];
3124 goto reg;
3126 #ifdef EXTRA_CONSTRAINT
3127 case 'Q':
3128 case 'R':
3129 case 'S':
3130 case 'T':
3131 case 'U':
3132 if (EXTRA_CONSTRAINT (operand, c))
3133 win = 1;
3134 break;
3135 #endif
3137 default:
3138 this_alternative[i]
3139 = (int) reg_class_subunion[this_alternative[i]][(int) REG_CLASS_FROM_LETTER (c)];
3141 reg:
3142 if (GET_MODE (operand) == BLKmode)
3143 break;
3144 winreg = 1;
3145 if (GET_CODE (operand) == REG
3146 && reg_fits_class_p (operand, this_alternative[i],
3147 offset, GET_MODE (recog_data.operand[i])))
3148 win = 1;
3149 break;
3152 constraints[i] = p;
3154 /* If this operand could be handled with a reg,
3155 and some reg is allowed, then this operand can be handled. */
3156 if (winreg && this_alternative[i] != (int) NO_REGS)
3157 badop = 0;
3159 /* Record which operands fit this alternative. */
3160 this_alternative_earlyclobber[i] = earlyclobber;
3161 if (win && ! force_reload)
3162 this_alternative_win[i] = 1;
3163 else
3165 int const_to_mem = 0;
3167 this_alternative_offmemok[i] = offmemok;
3168 losers++;
3169 if (badop)
3170 bad = 1;
3171 /* Alternative loses if it has no regs for a reg operand. */
3172 if (GET_CODE (operand) == REG
3173 && this_alternative[i] == (int) NO_REGS
3174 && this_alternative_matches[i] < 0)
3175 bad = 1;
3177 /* If this is a constant that is reloaded into the desired
3178 class by copying it to memory first, count that as another
3179 reload. This is consistent with other code and is
3180 required to avoid choosing another alternative when
3181 the constant is moved into memory by this function on
3182 an early reload pass. Note that the test here is
3183 precisely the same as in the code below that calls
3184 force_const_mem. */
3185 if (CONSTANT_P (operand)
3186 /* force_const_mem does not accept HIGH. */
3187 && GET_CODE (operand) != HIGH
3188 && ((PREFERRED_RELOAD_CLASS (operand,
3189 (enum reg_class) this_alternative[i])
3190 == NO_REGS)
3191 || no_input_reloads)
3192 && operand_mode[i] != VOIDmode)
3194 const_to_mem = 1;
3195 if (this_alternative[i] != (int) NO_REGS)
3196 losers++;
3199 /* If we can't reload this value at all, reject this
3200 alternative. Note that we could also lose due to
3201 LIMIT_RELOAD_RELOAD_CLASS, but we don't check that
3202 here. */
3204 if (! CONSTANT_P (operand)
3205 && (enum reg_class) this_alternative[i] != NO_REGS
3206 && (PREFERRED_RELOAD_CLASS (operand,
3207 (enum reg_class) this_alternative[i])
3208 == NO_REGS))
3209 bad = 1;
3211 /* Alternative loses if it requires a type of reload not
3212 permitted for this insn. We can always reload SCRATCH
3213 and objects with a REG_UNUSED note. */
3214 else if (GET_CODE (operand) != SCRATCH
3215 && modified[i] != RELOAD_READ && no_output_reloads
3216 && ! find_reg_note (insn, REG_UNUSED, operand))
3217 bad = 1;
3218 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3219 && ! const_to_mem)
3220 bad = 1;
3223 /* We prefer to reload pseudos over reloading other things,
3224 since such reloads may be able to be eliminated later.
3225 If we are reloading a SCRATCH, we won't be generating any
3226 insns, just using a register, so it is also preferred.
3227 So bump REJECT in other cases. Don't do this in the
3228 case where we are forcing a constant into memory and
3229 it will then win since we don't want to have a different
3230 alternative match then. */
3231 if (! (GET_CODE (operand) == REG
3232 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3233 && GET_CODE (operand) != SCRATCH
3234 && ! (const_to_mem && constmemok))
3235 reject += 2;
3237 /* Input reloads can be inherited more often than output
3238 reloads can be removed, so penalize output reloads. */
3239 if (operand_type[i] != RELOAD_FOR_INPUT
3240 && GET_CODE (operand) != SCRATCH)
3241 reject++;
3244 /* If this operand is a pseudo register that didn't get a hard
3245 reg and this alternative accepts some register, see if the
3246 class that we want is a subset of the preferred class for this
3247 register. If not, but it intersects that class, use the
3248 preferred class instead. If it does not intersect the preferred
3249 class, show that usage of this alternative should be discouraged;
3250 it will be discouraged more still if the register is `preferred
3251 or nothing'. We do this because it increases the chance of
3252 reusing our spill register in a later insn and avoiding a pair
3253 of memory stores and loads.
3255 Don't bother with this if this alternative will accept this
3256 operand.
3258 Don't do this for a multiword operand, since it is only a
3259 small win and has the risk of requiring more spill registers,
3260 which could cause a large loss.
3262 Don't do this if the preferred class has only one register
3263 because we might otherwise exhaust the class. */
3266 if (! win && this_alternative[i] != (int) NO_REGS
3267 && GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3268 && reg_class_size[(int) preferred_class[i]] > 1)
3270 if (! reg_class_subset_p (this_alternative[i],
3271 preferred_class[i]))
3273 /* Since we don't have a way of forming the intersection,
3274 we just do something special if the preferred class
3275 is a subset of the class we have; that's the most
3276 common case anyway. */
3277 if (reg_class_subset_p (preferred_class[i],
3278 this_alternative[i]))
3279 this_alternative[i] = (int) preferred_class[i];
3280 else
3281 reject += (2 + 2 * pref_or_nothing[i]);
3286 /* Now see if any output operands that are marked "earlyclobber"
3287 in this alternative conflict with any input operands
3288 or any memory addresses. */
3290 for (i = 0; i < noperands; i++)
3291 if (this_alternative_earlyclobber[i]
3292 && this_alternative_win[i])
3294 struct decomposition early_data;
3296 early_data = decompose (recog_data.operand[i]);
3298 if (modified[i] == RELOAD_READ)
3299 abort ();
3301 if (this_alternative[i] == NO_REGS)
3303 this_alternative_earlyclobber[i] = 0;
3304 if (this_insn_is_asm)
3305 error_for_asm (this_insn,
3306 "`&' constraint used with no register class");
3307 else
3308 abort ();
3311 for (j = 0; j < noperands; j++)
3312 /* Is this an input operand or a memory ref? */
3313 if ((GET_CODE (recog_data.operand[j]) == MEM
3314 || modified[j] != RELOAD_WRITE)
3315 && j != i
3316 /* Ignore things like match_operator operands. */
3317 && *recog_data.constraints[j] != 0
3318 /* Don't count an input operand that is constrained to match
3319 the early clobber operand. */
3320 && ! (this_alternative_matches[j] == i
3321 && rtx_equal_p (recog_data.operand[i],
3322 recog_data.operand[j]))
3323 /* Is it altered by storing the earlyclobber operand? */
3324 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3325 early_data))
3327 /* If the output is in a single-reg class,
3328 it's costly to reload it, so reload the input instead. */
3329 if (reg_class_size[this_alternative[i]] == 1
3330 && (GET_CODE (recog_data.operand[j]) == REG
3331 || GET_CODE (recog_data.operand[j]) == SUBREG))
3333 losers++;
3334 this_alternative_win[j] = 0;
3336 else
3337 break;
3339 /* If an earlyclobber operand conflicts with something,
3340 it must be reloaded, so request this and count the cost. */
3341 if (j != noperands)
3343 losers++;
3344 this_alternative_win[i] = 0;
3345 for (j = 0; j < noperands; j++)
3346 if (this_alternative_matches[j] == i
3347 && this_alternative_win[j])
3349 this_alternative_win[j] = 0;
3350 losers++;
3355 /* If one alternative accepts all the operands, no reload required,
3356 choose that alternative; don't consider the remaining ones. */
3357 if (losers == 0)
3359 /* Unswap these so that they are never swapped at `finish'. */
3360 if (commutative >= 0)
3362 recog_data.operand[commutative] = substed_operand[commutative];
3363 recog_data.operand[commutative + 1]
3364 = substed_operand[commutative + 1];
3366 for (i = 0; i < noperands; i++)
3368 goal_alternative_win[i] = 1;
3369 goal_alternative[i] = this_alternative[i];
3370 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3371 goal_alternative_matches[i] = this_alternative_matches[i];
3372 goal_alternative_earlyclobber[i]
3373 = this_alternative_earlyclobber[i];
3375 goal_alternative_number = this_alternative_number;
3376 goal_alternative_swapped = swapped;
3377 goal_earlyclobber = this_earlyclobber;
3378 goto finish;
3381 /* REJECT, set by the ! and ? constraint characters and when a register
3382 would be reloaded into a non-preferred class, discourages the use of
3383 this alternative for a reload goal. REJECT is incremented by six
3384 for each ? and two for each non-preferred class. */
3385 losers = losers * 6 + reject;
3387 /* If this alternative can be made to work by reloading,
3388 and it needs less reloading than the others checked so far,
3389 record it as the chosen goal for reloading. */
3390 if (! bad && best > losers)
3392 for (i = 0; i < noperands; i++)
3394 goal_alternative[i] = this_alternative[i];
3395 goal_alternative_win[i] = this_alternative_win[i];
3396 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3397 goal_alternative_matches[i] = this_alternative_matches[i];
3398 goal_alternative_earlyclobber[i]
3399 = this_alternative_earlyclobber[i];
3401 goal_alternative_swapped = swapped;
3402 best = losers;
3403 goal_alternative_number = this_alternative_number;
3404 goal_earlyclobber = this_earlyclobber;
3408 /* If insn is commutative (it's safe to exchange a certain pair of operands)
3409 then we need to try each alternative twice,
3410 the second time matching those two operands
3411 as if we had exchanged them.
3412 To do this, really exchange them in operands.
3414 If we have just tried the alternatives the second time,
3415 return operands to normal and drop through. */
3417 if (commutative >= 0)
3419 swapped = !swapped;
3420 if (swapped)
3422 register enum reg_class tclass;
3423 register int t;
3425 recog_data.operand[commutative] = substed_operand[commutative + 1];
3426 recog_data.operand[commutative + 1] = substed_operand[commutative];
3428 tclass = preferred_class[commutative];
3429 preferred_class[commutative] = preferred_class[commutative + 1];
3430 preferred_class[commutative + 1] = tclass;
3432 t = pref_or_nothing[commutative];
3433 pref_or_nothing[commutative] = pref_or_nothing[commutative + 1];
3434 pref_or_nothing[commutative + 1] = t;
3436 bcopy ((char *) recog_data.constraints, (char *) constraints,
3437 noperands * sizeof (char *));
3438 goto try_swapped;
3440 else
3442 recog_data.operand[commutative] = substed_operand[commutative];
3443 recog_data.operand[commutative + 1]
3444 = substed_operand[commutative + 1];
3448 /* The operands don't meet the constraints.
3449 goal_alternative describes the alternative
3450 that we could reach by reloading the fewest operands.
3451 Reload so as to fit it. */
3453 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3455 /* No alternative works with reloads?? */
3456 if (insn_code_number >= 0)
3457 fatal_insn ("Unable to generate reloads for:", insn);
3458 error_for_asm (insn, "inconsistent operand constraints in an `asm'");
3459 /* Avoid further trouble with this insn. */
3460 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3461 n_reloads = 0;
3462 return 0;
3465 /* Jump to `finish' from above if all operands are valid already.
3466 In that case, goal_alternative_win is all 1. */
3467 finish:
3469 /* Right now, for any pair of operands I and J that are required to match,
3470 with I < J,
3471 goal_alternative_matches[J] is I.
3472 Set up goal_alternative_matched as the inverse function:
3473 goal_alternative_matched[I] = J. */
3475 for (i = 0; i < noperands; i++)
3476 goal_alternative_matched[i] = -1;
3478 for (i = 0; i < noperands; i++)
3479 if (! goal_alternative_win[i]
3480 && goal_alternative_matches[i] >= 0)
3481 goal_alternative_matched[goal_alternative_matches[i]] = i;
3483 /* If the best alternative is with operands 1 and 2 swapped,
3484 consider them swapped before reporting the reloads. Update the
3485 operand numbers of any reloads already pushed. */
3487 if (goal_alternative_swapped)
3489 register rtx tem;
3491 tem = substed_operand[commutative];
3492 substed_operand[commutative] = substed_operand[commutative + 1];
3493 substed_operand[commutative + 1] = tem;
3494 tem = recog_data.operand[commutative];
3495 recog_data.operand[commutative] = recog_data.operand[commutative + 1];
3496 recog_data.operand[commutative + 1] = tem;
3497 tem = *recog_data.operand_loc[commutative];
3498 *recog_data.operand_loc[commutative]
3499 = *recog_data.operand_loc[commutative + 1];
3500 *recog_data.operand_loc[commutative+1] = tem;
3502 for (i = 0; i < n_reloads; i++)
3504 if (rld[i].opnum == commutative)
3505 rld[i].opnum = commutative + 1;
3506 else if (rld[i].opnum == commutative + 1)
3507 rld[i].opnum = commutative;
3511 for (i = 0; i < noperands; i++)
3513 operand_reloadnum[i] = -1;
3515 /* If this is an earlyclobber operand, we need to widen the scope.
3516 The reload must remain valid from the start of the insn being
3517 reloaded until after the operand is stored into its destination.
3518 We approximate this with RELOAD_OTHER even though we know that we
3519 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3521 One special case that is worth checking is when we have an
3522 output that is earlyclobber but isn't used past the insn (typically
3523 a SCRATCH). In this case, we only need have the reload live
3524 through the insn itself, but not for any of our input or output
3525 reloads.
3526 But we must not accidentally narrow the scope of an existing
3527 RELOAD_OTHER reload - leave these alone.
3529 In any case, anything needed to address this operand can remain
3530 however they were previously categorized. */
3532 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3533 operand_type[i]
3534 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3535 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3538 /* Any constants that aren't allowed and can't be reloaded
3539 into registers are here changed into memory references. */
3540 for (i = 0; i < noperands; i++)
3541 if (! goal_alternative_win[i]
3542 && CONSTANT_P (recog_data.operand[i])
3543 /* force_const_mem does not accept HIGH. */
3544 && GET_CODE (recog_data.operand[i]) != HIGH
3545 && ((PREFERRED_RELOAD_CLASS (recog_data.operand[i],
3546 (enum reg_class) goal_alternative[i])
3547 == NO_REGS)
3548 || no_input_reloads)
3549 && operand_mode[i] != VOIDmode)
3551 substed_operand[i] = recog_data.operand[i]
3552 = find_reloads_toplev (force_const_mem (operand_mode[i],
3553 recog_data.operand[i]),
3554 i, address_type[i], ind_levels, 0, insn);
3555 if (alternative_allows_memconst (recog_data.constraints[i],
3556 goal_alternative_number))
3557 goal_alternative_win[i] = 1;
3560 /* Record the values of the earlyclobber operands for the caller. */
3561 if (goal_earlyclobber)
3562 for (i = 0; i < noperands; i++)
3563 if (goal_alternative_earlyclobber[i])
3564 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3566 /* Now record reloads for all the operands that need them. */
3567 for (i = 0; i < noperands; i++)
3568 if (! goal_alternative_win[i])
3570 /* Operands that match previous ones have already been handled. */
3571 if (goal_alternative_matches[i] >= 0)
3573 /* Handle an operand with a nonoffsettable address
3574 appearing where an offsettable address will do
3575 by reloading the address into a base register.
3577 ??? We can also do this when the operand is a register and
3578 reg_equiv_mem is not offsettable, but this is a bit tricky,
3579 so we don't bother with it. It may not be worth doing. */
3580 else if (goal_alternative_matched[i] == -1
3581 && goal_alternative_offmemok[i]
3582 && GET_CODE (recog_data.operand[i]) == MEM)
3584 operand_reloadnum[i]
3585 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
3586 &XEXP (recog_data.operand[i], 0), NULL_PTR,
3587 BASE_REG_CLASS,
3588 GET_MODE (XEXP (recog_data.operand[i], 0)),
3589 VOIDmode, 0, 0, i, RELOAD_FOR_INPUT);
3590 rld[operand_reloadnum[i]].inc
3591 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
3593 /* If this operand is an output, we will have made any
3594 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
3595 now we are treating part of the operand as an input, so
3596 we must change these to RELOAD_FOR_INPUT_ADDRESS. */
3598 if (modified[i] == RELOAD_WRITE)
3600 for (j = 0; j < n_reloads; j++)
3602 if (rld[j].opnum == i)
3604 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
3605 rld[j].when_needed = RELOAD_FOR_INPUT_ADDRESS;
3606 else if (rld[j].when_needed
3607 == RELOAD_FOR_OUTADDR_ADDRESS)
3608 rld[j].when_needed = RELOAD_FOR_INPADDR_ADDRESS;
3613 else if (goal_alternative_matched[i] == -1)
3615 operand_reloadnum[i]
3616 = push_reload ((modified[i] != RELOAD_WRITE
3617 ? recog_data.operand[i] : 0),
3618 (modified[i] != RELOAD_READ
3619 ? recog_data.operand[i] : 0),
3620 (modified[i] != RELOAD_WRITE
3621 ? recog_data.operand_loc[i] : 0),
3622 (modified[i] != RELOAD_READ
3623 ? recog_data.operand_loc[i] : 0),
3624 (enum reg_class) goal_alternative[i],
3625 (modified[i] == RELOAD_WRITE
3626 ? VOIDmode : operand_mode[i]),
3627 (modified[i] == RELOAD_READ
3628 ? VOIDmode : operand_mode[i]),
3629 (insn_code_number < 0 ? 0
3630 : insn_data[insn_code_number].operand[i].strict_low),
3631 0, i, operand_type[i]);
3633 /* In a matching pair of operands, one must be input only
3634 and the other must be output only.
3635 Pass the input operand as IN and the other as OUT. */
3636 else if (modified[i] == RELOAD_READ
3637 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
3639 operand_reloadnum[i]
3640 = push_reload (recog_data.operand[i],
3641 recog_data.operand[goal_alternative_matched[i]],
3642 recog_data.operand_loc[i],
3643 recog_data.operand_loc[goal_alternative_matched[i]],
3644 (enum reg_class) goal_alternative[i],
3645 operand_mode[i],
3646 operand_mode[goal_alternative_matched[i]],
3647 0, 0, i, RELOAD_OTHER);
3648 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
3650 else if (modified[i] == RELOAD_WRITE
3651 && modified[goal_alternative_matched[i]] == RELOAD_READ)
3653 operand_reloadnum[goal_alternative_matched[i]]
3654 = push_reload (recog_data.operand[goal_alternative_matched[i]],
3655 recog_data.operand[i],
3656 recog_data.operand_loc[goal_alternative_matched[i]],
3657 recog_data.operand_loc[i],
3658 (enum reg_class) goal_alternative[i],
3659 operand_mode[goal_alternative_matched[i]],
3660 operand_mode[i],
3661 0, 0, i, RELOAD_OTHER);
3662 operand_reloadnum[i] = output_reloadnum;
3664 else if (insn_code_number >= 0)
3665 abort ();
3666 else
3668 error_for_asm (insn, "inconsistent operand constraints in an `asm'");
3669 /* Avoid further trouble with this insn. */
3670 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3671 n_reloads = 0;
3672 return 0;
3675 else if (goal_alternative_matched[i] < 0
3676 && goal_alternative_matches[i] < 0
3677 && optimize)
3679 /* For each non-matching operand that's a MEM or a pseudo-register
3680 that didn't get a hard register, make an optional reload.
3681 This may get done even if the insn needs no reloads otherwise. */
3683 rtx operand = recog_data.operand[i];
3685 while (GET_CODE (operand) == SUBREG)
3686 operand = XEXP (operand, 0);
3687 if ((GET_CODE (operand) == MEM
3688 || (GET_CODE (operand) == REG
3689 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3690 /* If this is only for an output, the optional reload would not
3691 actually cause us to use a register now, just note that
3692 something is stored here. */
3693 && ((enum reg_class) goal_alternative[i] != NO_REGS
3694 || modified[i] == RELOAD_WRITE)
3695 && ! no_input_reloads
3696 /* An optional output reload might allow to delete INSN later.
3697 We mustn't make in-out reloads on insns that are not permitted
3698 output reloads.
3699 If this is an asm, we can't delete it; we must not even call
3700 push_reload for an optional output reload in this case,
3701 because we can't be sure that the constraint allows a register,
3702 and push_reload verifies the constraints for asms. */
3703 && (modified[i] == RELOAD_READ
3704 || (! no_output_reloads && ! this_insn_is_asm)))
3705 operand_reloadnum[i]
3706 = push_reload ((modified[i] != RELOAD_WRITE
3707 ? recog_data.operand[i] : 0),
3708 (modified[i] != RELOAD_READ
3709 ? recog_data.operand[i] : 0),
3710 (modified[i] != RELOAD_WRITE
3711 ? recog_data.operand_loc[i] : 0),
3712 (modified[i] != RELOAD_READ
3713 ? recog_data.operand_loc[i] : 0),
3714 (enum reg_class) goal_alternative[i],
3715 (modified[i] == RELOAD_WRITE
3716 ? VOIDmode : operand_mode[i]),
3717 (modified[i] == RELOAD_READ
3718 ? VOIDmode : operand_mode[i]),
3719 (insn_code_number < 0 ? 0
3720 : insn_data[insn_code_number].operand[i].strict_low),
3721 1, i, operand_type[i]);
3722 /* If a memory reference remains (either as a MEM or a pseudo that
3723 did not get a hard register), yet we can't make an optional
3724 reload, check if this is actually a pseudo register reference;
3725 we then need to emit a USE and/or a CLOBBER so that reload
3726 inheritance will do the right thing. */
3727 else if (replace
3728 && (GET_CODE (operand) == MEM
3729 || (GET_CODE (operand) == REG
3730 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3731 && reg_renumber [REGNO (operand)] < 0)))
3733 operand = *recog_data.operand_loc[i];
3735 while (GET_CODE (operand) == SUBREG)
3736 operand = XEXP (operand, 0);
3737 if (GET_CODE (operand) == REG)
3739 if (modified[i] != RELOAD_WRITE)
3740 emit_insn_before (gen_rtx_USE (VOIDmode, operand), insn);
3741 if (modified[i] != RELOAD_READ)
3742 emit_insn_after (gen_rtx_CLOBBER (VOIDmode, operand), insn);
3746 else if (goal_alternative_matches[i] >= 0
3747 && goal_alternative_win[goal_alternative_matches[i]]
3748 && modified[i] == RELOAD_READ
3749 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
3750 && ! no_input_reloads && ! no_output_reloads
3751 && optimize)
3753 /* Similarly, make an optional reload for a pair of matching
3754 objects that are in MEM or a pseudo that didn't get a hard reg. */
3756 rtx operand = recog_data.operand[i];
3758 while (GET_CODE (operand) == SUBREG)
3759 operand = XEXP (operand, 0);
3760 if ((GET_CODE (operand) == MEM
3761 || (GET_CODE (operand) == REG
3762 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3763 && ((enum reg_class) goal_alternative[goal_alternative_matches[i]]
3764 != NO_REGS))
3765 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
3766 = push_reload (recog_data.operand[goal_alternative_matches[i]],
3767 recog_data.operand[i],
3768 recog_data.operand_loc[goal_alternative_matches[i]],
3769 recog_data.operand_loc[i],
3770 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
3771 operand_mode[goal_alternative_matches[i]],
3772 operand_mode[i],
3773 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
3776 /* Perform whatever substitutions on the operands we are supposed
3777 to make due to commutativity or replacement of registers
3778 with equivalent constants or memory slots. */
3780 for (i = 0; i < noperands; i++)
3782 /* We only do this on the last pass through reload, because it is
3783 possible for some data (like reg_equiv_address) to be changed during
3784 later passes. Moreover, we loose the opportunity to get a useful
3785 reload_{in,out}_reg when we do these replacements. */
3787 if (replace)
3789 rtx substitution = substed_operand[i];
3791 *recog_data.operand_loc[i] = substitution;
3793 /* If we're replacing an operand with a LABEL_REF, we need
3794 to make sure that there's a REG_LABEL note attached to
3795 this instruction. */
3796 if (GET_CODE (insn) != JUMP_INSN
3797 && GET_CODE (substitution) == LABEL_REF
3798 && !find_reg_note (insn, REG_LABEL, XEXP (substitution, 0)))
3799 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_LABEL,
3800 XEXP (substitution, 0),
3801 REG_NOTES (insn));
3803 else
3804 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
3807 /* If this insn pattern contains any MATCH_DUP's, make sure that
3808 they will be substituted if the operands they match are substituted.
3809 Also do now any substitutions we already did on the operands.
3811 Don't do this if we aren't making replacements because we might be
3812 propagating things allocated by frame pointer elimination into places
3813 it doesn't expect. */
3815 if (insn_code_number >= 0 && replace)
3816 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
3818 int opno = recog_data.dup_num[i];
3819 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
3820 if (operand_reloadnum[opno] >= 0)
3821 push_replacement (recog_data.dup_loc[i], operand_reloadnum[opno],
3822 insn_data[insn_code_number].operand[opno].mode);
3825 #if 0
3826 /* This loses because reloading of prior insns can invalidate the equivalence
3827 (or at least find_equiv_reg isn't smart enough to find it any more),
3828 causing this insn to need more reload regs than it needed before.
3829 It may be too late to make the reload regs available.
3830 Now this optimization is done safely in choose_reload_regs. */
3832 /* For each reload of a reg into some other class of reg,
3833 search for an existing equivalent reg (same value now) in the right class.
3834 We can use it as long as we don't need to change its contents. */
3835 for (i = 0; i < n_reloads; i++)
3836 if (rld[i].reg_rtx == 0
3837 && rld[i].in != 0
3838 && GET_CODE (rld[i].in) == REG
3839 && rld[i].out == 0)
3841 rld[i].reg_rtx
3842 = find_equiv_reg (rld[i].in, insn, rld[i].class, -1,
3843 static_reload_reg_p, 0, rld[i].inmode);
3844 /* Prevent generation of insn to load the value
3845 because the one we found already has the value. */
3846 if (rld[i].reg_rtx)
3847 rld[i].in = rld[i].reg_rtx;
3849 #endif
3851 /* Perhaps an output reload can be combined with another
3852 to reduce needs by one. */
3853 if (!goal_earlyclobber)
3854 combine_reloads ();
3856 /* If we have a pair of reloads for parts of an address, they are reloading
3857 the same object, the operands themselves were not reloaded, and they
3858 are for two operands that are supposed to match, merge the reloads and
3859 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
3861 for (i = 0; i < n_reloads; i++)
3863 int k;
3865 for (j = i + 1; j < n_reloads; j++)
3866 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
3867 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
3868 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
3869 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
3870 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
3871 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
3872 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
3873 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
3874 && rtx_equal_p (rld[i].in, rld[j].in)
3875 && (operand_reloadnum[rld[i].opnum] < 0
3876 || rld[operand_reloadnum[rld[i].opnum]].optional)
3877 && (operand_reloadnum[rld[j].opnum] < 0
3878 || rld[operand_reloadnum[rld[j].opnum]].optional)
3879 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
3880 || (goal_alternative_matches[rld[j].opnum]
3881 == rld[i].opnum)))
3883 for (k = 0; k < n_replacements; k++)
3884 if (replacements[k].what == j)
3885 replacements[k].what = i;
3887 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
3888 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
3889 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
3890 else
3891 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
3892 rld[j].in = 0;
3896 /* Scan all the reloads and update their type.
3897 If a reload is for the address of an operand and we didn't reload
3898 that operand, change the type. Similarly, change the operand number
3899 of a reload when two operands match. If a reload is optional, treat it
3900 as though the operand isn't reloaded.
3902 ??? This latter case is somewhat odd because if we do the optional
3903 reload, it means the object is hanging around. Thus we need only
3904 do the address reload if the optional reload was NOT done.
3906 Change secondary reloads to be the address type of their operand, not
3907 the normal type.
3909 If an operand's reload is now RELOAD_OTHER, change any
3910 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
3911 RELOAD_FOR_OTHER_ADDRESS. */
3913 for (i = 0; i < n_reloads; i++)
3915 if (rld[i].secondary_p
3916 && rld[i].when_needed == operand_type[rld[i].opnum])
3917 rld[i].when_needed = address_type[rld[i].opnum];
3919 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
3920 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
3921 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
3922 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
3923 && (operand_reloadnum[rld[i].opnum] < 0
3924 || rld[operand_reloadnum[rld[i].opnum]].optional))
3926 /* If we have a secondary reload to go along with this reload,
3927 change its type to RELOAD_FOR_OPADDR_ADDR. */
3929 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
3930 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
3931 && rld[i].secondary_in_reload != -1)
3933 int secondary_in_reload = rld[i].secondary_in_reload;
3935 rld[secondary_in_reload].when_needed
3936 = RELOAD_FOR_OPADDR_ADDR;
3938 /* If there's a tertiary reload we have to change it also. */
3939 if (secondary_in_reload > 0
3940 && rld[secondary_in_reload].secondary_in_reload != -1)
3941 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
3942 = RELOAD_FOR_OPADDR_ADDR;
3945 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
3946 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
3947 && rld[i].secondary_out_reload != -1)
3949 int secondary_out_reload = rld[i].secondary_out_reload;
3951 rld[secondary_out_reload].when_needed
3952 = RELOAD_FOR_OPADDR_ADDR;
3954 /* If there's a tertiary reload we have to change it also. */
3955 if (secondary_out_reload
3956 && rld[secondary_out_reload].secondary_out_reload != -1)
3957 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
3958 = RELOAD_FOR_OPADDR_ADDR;
3961 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
3962 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
3963 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
3964 else
3965 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
3968 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
3969 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
3970 && operand_reloadnum[rld[i].opnum] >= 0
3971 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
3972 == RELOAD_OTHER))
3973 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
3975 if (goal_alternative_matches[rld[i].opnum] >= 0)
3976 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
3979 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
3980 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
3981 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
3983 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
3984 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
3985 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
3986 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
3987 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
3988 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
3989 This is complicated by the fact that a single operand can have more
3990 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
3991 choose_reload_regs without affecting code quality, and cases that
3992 actually fail are extremely rare, so it turns out to be better to fix
3993 the problem here by not generating cases that choose_reload_regs will
3994 fail for. */
3995 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
3996 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
3997 a single operand.
3998 We can reduce the register pressure by exploiting that a
3999 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4000 does not conflict with any of them, if it is only used for the first of
4001 the RELOAD_FOR_X_ADDRESS reloads. */
4003 int first_op_addr_num = -2;
4004 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4005 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4006 int need_change= 0;
4007 /* We use last_op_addr_reload and the contents of the above arrays
4008 first as flags - -2 means no instance encountered, -1 means exactly
4009 one instance encountered.
4010 If more than one instance has been encountered, we store the reload
4011 number of the first reload of the kind in question; reload numbers
4012 are known to be non-negative. */
4013 for (i = 0; i < noperands; i++)
4014 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4015 for (i = n_reloads - 1; i >= 0; i--)
4017 switch (rld[i].when_needed)
4019 case RELOAD_FOR_OPERAND_ADDRESS:
4020 if (++first_op_addr_num >= 0)
4022 first_op_addr_num = i;
4023 need_change = 1;
4025 break;
4026 case RELOAD_FOR_INPUT_ADDRESS:
4027 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4029 first_inpaddr_num[rld[i].opnum] = i;
4030 need_change = 1;
4032 break;
4033 case RELOAD_FOR_OUTPUT_ADDRESS:
4034 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4036 first_outpaddr_num[rld[i].opnum] = i;
4037 need_change = 1;
4039 break;
4040 default:
4041 break;
4045 if (need_change)
4047 for (i = 0; i < n_reloads; i++)
4049 int first_num, type;
4051 switch (rld[i].when_needed)
4053 case RELOAD_FOR_OPADDR_ADDR:
4054 first_num = first_op_addr_num;
4055 type = RELOAD_FOR_OPERAND_ADDRESS;
4056 break;
4057 case RELOAD_FOR_INPADDR_ADDRESS:
4058 first_num = first_inpaddr_num[rld[i].opnum];
4059 type = RELOAD_FOR_INPUT_ADDRESS;
4060 break;
4061 case RELOAD_FOR_OUTADDR_ADDRESS:
4062 first_num = first_outpaddr_num[rld[i].opnum];
4063 type = RELOAD_FOR_OUTPUT_ADDRESS;
4064 break;
4065 default:
4066 continue;
4068 if (first_num < 0)
4069 continue;
4070 else if (i > first_num)
4071 rld[i].when_needed = type;
4072 else
4074 /* Check if the only TYPE reload that uses reload I is
4075 reload FIRST_NUM. */
4076 for (j = n_reloads - 1; j > first_num; j--)
4078 if (rld[j].when_needed == type
4079 && (rld[i].secondary_p
4080 ? rld[j].secondary_in_reload == i
4081 : reg_mentioned_p (rld[i].in, rld[j].in)))
4083 rld[i].when_needed = type;
4084 break;
4092 /* See if we have any reloads that are now allowed to be merged
4093 because we've changed when the reload is needed to
4094 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4095 check for the most common cases. */
4097 for (i = 0; i < n_reloads; i++)
4098 if (rld[i].in != 0 && rld[i].out == 0
4099 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4100 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4101 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4102 for (j = 0; j < n_reloads; j++)
4103 if (i != j && rld[j].in != 0 && rld[j].out == 0
4104 && rld[j].when_needed == rld[i].when_needed
4105 && MATCHES (rld[i].in, rld[j].in)
4106 && rld[i].class == rld[j].class
4107 && !rld[i].nocombine && !rld[j].nocombine
4108 && rld[i].reg_rtx == rld[j].reg_rtx)
4110 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4111 transfer_replacements (i, j);
4112 rld[j].in = 0;
4115 /* Set which reloads must use registers not used in any group. Start
4116 with those that conflict with a group and then include ones that
4117 conflict with ones that are already known to conflict with a group. */
4119 changed = 0;
4120 for (i = 0; i < n_reloads; i++)
4122 enum machine_mode mode = rld[i].inmode;
4123 enum reg_class class = rld[i].class;
4124 int size;
4126 if (GET_MODE_SIZE (rld[i].outmode) > GET_MODE_SIZE (mode))
4127 mode = rld[i].outmode;
4128 size = CLASS_MAX_NREGS (class, mode);
4130 if (size == 1)
4131 for (j = 0; j < n_reloads; j++)
4132 if ((CLASS_MAX_NREGS (rld[j].class,
4133 (GET_MODE_SIZE (rld[j].outmode)
4134 > GET_MODE_SIZE (rld[j].inmode))
4135 ? rld[j].outmode : rld[j].inmode)
4136 > 1)
4137 && !rld[j].optional
4138 && (rld[j].in != 0 || rld[j].out != 0
4139 || rld[j].secondary_p)
4140 && reloads_conflict (i, j)
4141 && reg_classes_intersect_p (class, rld[j].class))
4143 rld[i].nongroup = 1;
4144 changed = 1;
4145 break;
4149 while (changed)
4151 changed = 0;
4153 for (i = 0; i < n_reloads; i++)
4155 enum machine_mode mode = rld[i].inmode;
4156 enum reg_class class = rld[i].class;
4157 int size;
4159 if (GET_MODE_SIZE (rld[i].outmode) > GET_MODE_SIZE (mode))
4160 mode = rld[i].outmode;
4161 size = CLASS_MAX_NREGS (class, mode);
4163 if (! rld[i].nongroup && size == 1)
4164 for (j = 0; j < n_reloads; j++)
4165 if (rld[j].nongroup
4166 && reloads_conflict (i, j)
4167 && reg_classes_intersect_p (class, rld[j].class))
4169 rld[i].nongroup = 1;
4170 changed = 1;
4171 break;
4176 return retval;
4179 /* Return 1 if alternative number ALTNUM in constraint-string CONSTRAINT
4180 accepts a memory operand with constant address. */
4182 static int
4183 alternative_allows_memconst (constraint, altnum)
4184 const char *constraint;
4185 int altnum;
4187 register int c;
4188 /* Skip alternatives before the one requested. */
4189 while (altnum > 0)
4191 while (*constraint++ != ',');
4192 altnum--;
4194 /* Scan the requested alternative for 'm' or 'o'.
4195 If one of them is present, this alternative accepts memory constants. */
4196 while ((c = *constraint++) && c != ',' && c != '#')
4197 if (c == 'm' || c == 'o')
4198 return 1;
4199 return 0;
4202 /* Scan X for memory references and scan the addresses for reloading.
4203 Also checks for references to "constant" regs that we want to eliminate
4204 and replaces them with the values they stand for.
4205 We may alter X destructively if it contains a reference to such.
4206 If X is just a constant reg, we return the equivalent value
4207 instead of X.
4209 IND_LEVELS says how many levels of indirect addressing this machine
4210 supports.
4212 OPNUM and TYPE identify the purpose of the reload.
4214 IS_SET_DEST is true if X is the destination of a SET, which is not
4215 appropriate to be replaced by a constant.
4217 INSN, if nonzero, is the insn in which we do the reload. It is used
4218 to determine if we may generate output reloads, and where to put USEs
4219 for pseudos that we have to replace with stack slots. */
4221 static rtx
4222 find_reloads_toplev (x, opnum, type, ind_levels, is_set_dest, insn)
4223 rtx x;
4224 int opnum;
4225 enum reload_type type;
4226 int ind_levels;
4227 int is_set_dest;
4228 rtx insn;
4230 register RTX_CODE code = GET_CODE (x);
4232 register const char *fmt = GET_RTX_FORMAT (code);
4233 register int i;
4234 int copied;
4236 if (code == REG)
4238 /* This code is duplicated for speed in find_reloads. */
4239 register int regno = REGNO (x);
4240 if (reg_equiv_constant[regno] != 0 && !is_set_dest)
4241 x = reg_equiv_constant[regno];
4242 #if 0
4243 /* This creates (subreg (mem...)) which would cause an unnecessary
4244 reload of the mem. */
4245 else if (reg_equiv_mem[regno] != 0)
4246 x = reg_equiv_mem[regno];
4247 #endif
4248 else if (reg_equiv_memory_loc[regno]
4249 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
4251 rtx mem = make_memloc (x, regno);
4252 if (reg_equiv_address[regno]
4253 || ! rtx_equal_p (mem, reg_equiv_mem[regno]))
4255 /* If this is not a toplevel operand, find_reloads doesn't see
4256 this substitution. We have to emit a USE of the pseudo so
4257 that delete_output_reload can see it. */
4258 if (replace_reloads && recog_data.operand[opnum] != x)
4259 emit_insn_before (gen_rtx_USE (VOIDmode, x), insn);
4260 x = mem;
4261 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4262 opnum, type, ind_levels, insn);
4265 return x;
4267 if (code == MEM)
4269 rtx tem = x;
4270 find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4271 opnum, type, ind_levels, insn);
4272 return tem;
4275 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == REG)
4277 /* Check for SUBREG containing a REG that's equivalent to a constant.
4278 If the constant has a known value, truncate it right now.
4279 Similarly if we are extracting a single-word of a multi-word
4280 constant. If the constant is symbolic, allow it to be substituted
4281 normally. push_reload will strip the subreg later. If the
4282 constant is VOIDmode, abort because we will lose the mode of
4283 the register (this should never happen because one of the cases
4284 above should handle it). */
4286 register int regno = REGNO (SUBREG_REG (x));
4287 rtx tem;
4289 if (subreg_lowpart_p (x)
4290 && regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
4291 && reg_equiv_constant[regno] != 0
4292 && (tem = gen_lowpart_common (GET_MODE (x),
4293 reg_equiv_constant[regno])) != 0)
4294 return tem;
4296 if (GET_MODE_BITSIZE (GET_MODE (x)) == BITS_PER_WORD
4297 && regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
4298 && reg_equiv_constant[regno] != 0
4299 && (tem = operand_subword (reg_equiv_constant[regno],
4300 SUBREG_WORD (x), 0,
4301 GET_MODE (SUBREG_REG (x)))) != 0)
4303 /* TEM is now a word sized constant for the bits from X that
4304 we wanted. However, TEM may be the wrong representation.
4306 Use gen_lowpart_common to convert a CONST_INT into a
4307 CONST_DOUBLE and vice versa as needed according to by the mode
4308 of the SUBREG. */
4309 tem = gen_lowpart_common (GET_MODE (x), tem);
4310 if (!tem)
4311 abort ();
4312 return tem;
4315 /* If the SUBREG is wider than a word, the above test will fail.
4316 For example, we might have a SImode SUBREG of a DImode SUBREG_REG
4317 for a 16 bit target, or a DImode SUBREG of a TImode SUBREG_REG for
4318 a 32 bit target. We still can - and have to - handle this
4319 for non-paradoxical subregs of CONST_INTs. */
4320 if (regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
4321 && reg_equiv_constant[regno] != 0
4322 && GET_CODE (reg_equiv_constant[regno]) == CONST_INT
4323 && (GET_MODE_SIZE (GET_MODE (x))
4324 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))))
4326 int shift = SUBREG_WORD (x) * BITS_PER_WORD;
4327 if (WORDS_BIG_ENDIAN)
4328 shift = (GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x)))
4329 - GET_MODE_BITSIZE (GET_MODE (x))
4330 - shift);
4331 /* Here we use the knowledge that CONST_INTs have a
4332 HOST_WIDE_INT field. */
4333 if (shift >= HOST_BITS_PER_WIDE_INT)
4334 shift = HOST_BITS_PER_WIDE_INT - 1;
4335 return GEN_INT (INTVAL (reg_equiv_constant[regno]) >> shift);
4338 if (regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
4339 && reg_equiv_constant[regno] != 0
4340 && GET_MODE (reg_equiv_constant[regno]) == VOIDmode)
4341 abort ();
4343 /* If the subreg contains a reg that will be converted to a mem,
4344 convert the subreg to a narrower memref now.
4345 Otherwise, we would get (subreg (mem ...) ...),
4346 which would force reload of the mem.
4348 We also need to do this if there is an equivalent MEM that is
4349 not offsettable. In that case, alter_subreg would produce an
4350 invalid address on big-endian machines.
4352 For machines that extend byte loads, we must not reload using
4353 a wider mode if we have a paradoxical SUBREG. find_reloads will
4354 force a reload in that case. So we should not do anything here. */
4356 else if (regno >= FIRST_PSEUDO_REGISTER
4357 #ifdef LOAD_EXTEND_OP
4358 && (GET_MODE_SIZE (GET_MODE (x))
4359 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
4360 #endif
4361 && (reg_equiv_address[regno] != 0
4362 || (reg_equiv_mem[regno] != 0
4363 && (! strict_memory_address_p (GET_MODE (x),
4364 XEXP (reg_equiv_mem[regno], 0))
4365 || ! offsettable_memref_p (reg_equiv_mem[regno])
4366 || num_not_at_initial_offset))))
4367 x = find_reloads_subreg_address (x, 1, opnum, type, ind_levels,
4368 insn);
4371 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4373 if (fmt[i] == 'e')
4375 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4376 ind_levels, is_set_dest, insn);
4377 /* If we have replaced a reg with it's equivalent memory loc -
4378 that can still be handled here e.g. if it's in a paradoxical
4379 subreg - we must make the change in a copy, rather than using
4380 a destructive change. This way, find_reloads can still elect
4381 not to do the change. */
4382 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4384 x = shallow_copy_rtx (x);
4385 copied = 1;
4387 XEXP (x, i) = new_part;
4390 return x;
4393 /* Return a mem ref for the memory equivalent of reg REGNO.
4394 This mem ref is not shared with anything. */
4396 static rtx
4397 make_memloc (ad, regno)
4398 rtx ad;
4399 int regno;
4401 /* We must rerun eliminate_regs, in case the elimination
4402 offsets have changed. */
4403 rtx tem
4404 = XEXP (eliminate_regs (reg_equiv_memory_loc[regno], 0, NULL_RTX), 0);
4406 /* If TEM might contain a pseudo, we must copy it to avoid
4407 modifying it when we do the substitution for the reload. */
4408 if (rtx_varies_p (tem))
4409 tem = copy_rtx (tem);
4411 tem = gen_rtx_MEM (GET_MODE (ad), tem);
4412 RTX_UNCHANGING_P (tem) = RTX_UNCHANGING_P (regno_reg_rtx[regno]);
4413 return tem;
4416 /* Record all reloads needed for handling memory address AD
4417 which appears in *LOC in a memory reference to mode MODE
4418 which itself is found in location *MEMREFLOC.
4419 Note that we take shortcuts assuming that no multi-reg machine mode
4420 occurs as part of an address.
4422 OPNUM and TYPE specify the purpose of this reload.
4424 IND_LEVELS says how many levels of indirect addressing this machine
4425 supports.
4427 INSN, if nonzero, is the insn in which we do the reload. It is used
4428 to determine if we may generate output reloads, and where to put USEs
4429 for pseudos that we have to replace with stack slots.
4431 Value is nonzero if this address is reloaded or replaced as a whole.
4432 This is interesting to the caller if the address is an autoincrement.
4434 Note that there is no verification that the address will be valid after
4435 this routine does its work. Instead, we rely on the fact that the address
4436 was valid when reload started. So we need only undo things that reload
4437 could have broken. These are wrong register types, pseudos not allocated
4438 to a hard register, and frame pointer elimination. */
4440 static int
4441 find_reloads_address (mode, memrefloc, ad, loc, opnum, type, ind_levels, insn)
4442 enum machine_mode mode;
4443 rtx *memrefloc;
4444 rtx ad;
4445 rtx *loc;
4446 int opnum;
4447 enum reload_type type;
4448 int ind_levels;
4449 rtx insn;
4451 register int regno;
4452 int removed_and = 0;
4453 rtx tem;
4455 /* If the address is a register, see if it is a legitimate address and
4456 reload if not. We first handle the cases where we need not reload
4457 or where we must reload in a non-standard way. */
4459 if (GET_CODE (ad) == REG)
4461 regno = REGNO (ad);
4463 if (reg_equiv_constant[regno] != 0
4464 && strict_memory_address_p (mode, reg_equiv_constant[regno]))
4466 *loc = ad = reg_equiv_constant[regno];
4467 return 0;
4470 tem = reg_equiv_memory_loc[regno];
4471 if (tem != 0)
4473 if (reg_equiv_address[regno] != 0 || num_not_at_initial_offset)
4475 tem = make_memloc (ad, regno);
4476 if (! strict_memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
4478 find_reloads_address (GET_MODE (tem), NULL_PTR, XEXP (tem, 0),
4479 &XEXP (tem, 0), opnum, ADDR_TYPE (type),
4480 ind_levels, insn);
4482 /* We can avoid a reload if the register's equivalent memory
4483 expression is valid as an indirect memory address.
4484 But not all addresses are valid in a mem used as an indirect
4485 address: only reg or reg+constant. */
4487 if (ind_levels > 0
4488 && strict_memory_address_p (mode, tem)
4489 && (GET_CODE (XEXP (tem, 0)) == REG
4490 || (GET_CODE (XEXP (tem, 0)) == PLUS
4491 && GET_CODE (XEXP (XEXP (tem, 0), 0)) == REG
4492 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4494 /* TEM is not the same as what we'll be replacing the
4495 pseudo with after reload, put a USE in front of INSN
4496 in the final reload pass. */
4497 if (replace_reloads
4498 && num_not_at_initial_offset
4499 && ! rtx_equal_p (tem, reg_equiv_mem[regno]))
4501 *loc = tem;
4502 emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn);
4503 /* This doesn't really count as replacing the address
4504 as a whole, since it is still a memory access. */
4506 return 0;
4508 ad = tem;
4512 /* The only remaining case where we can avoid a reload is if this is a
4513 hard register that is valid as a base register and which is not the
4514 subject of a CLOBBER in this insn. */
4516 else if (regno < FIRST_PSEUDO_REGISTER
4517 && REGNO_MODE_OK_FOR_BASE_P (regno, mode)
4518 && ! regno_clobbered_p (regno, this_insn))
4519 return 0;
4521 /* If we do not have one of the cases above, we must do the reload. */
4522 push_reload (ad, NULL_RTX, loc, NULL_PTR, BASE_REG_CLASS,
4523 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4524 return 1;
4527 if (strict_memory_address_p (mode, ad))
4529 /* The address appears valid, so reloads are not needed.
4530 But the address may contain an eliminable register.
4531 This can happen because a machine with indirect addressing
4532 may consider a pseudo register by itself a valid address even when
4533 it has failed to get a hard reg.
4534 So do a tree-walk to find and eliminate all such regs. */
4536 /* But first quickly dispose of a common case. */
4537 if (GET_CODE (ad) == PLUS
4538 && GET_CODE (XEXP (ad, 1)) == CONST_INT
4539 && GET_CODE (XEXP (ad, 0)) == REG
4540 && reg_equiv_constant[REGNO (XEXP (ad, 0))] == 0)
4541 return 0;
4543 subst_reg_equivs_changed = 0;
4544 *loc = subst_reg_equivs (ad, insn);
4546 if (! subst_reg_equivs_changed)
4547 return 0;
4549 /* Check result for validity after substitution. */
4550 if (strict_memory_address_p (mode, ad))
4551 return 0;
4554 #ifdef LEGITIMIZE_RELOAD_ADDRESS
4557 if (memrefloc)
4559 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
4560 ind_levels, win);
4562 break;
4563 win:
4564 *memrefloc = copy_rtx (*memrefloc);
4565 XEXP (*memrefloc, 0) = ad;
4566 move_replacements (&ad, &XEXP (*memrefloc, 0));
4567 return 1;
4569 while (0);
4570 #endif
4572 /* The address is not valid. We have to figure out why. First see if
4573 we have an outer AND and remove it if so. Then analyze what's inside. */
4575 if (GET_CODE (ad) == AND)
4577 removed_and = 1;
4578 loc = &XEXP (ad, 0);
4579 ad = *loc;
4582 /* One possibility for why the address is invalid is that it is itself
4583 a MEM. This can happen when the frame pointer is being eliminated, a
4584 pseudo is not allocated to a hard register, and the offset between the
4585 frame and stack pointers is not its initial value. In that case the
4586 pseudo will have been replaced by a MEM referring to the
4587 stack pointer. */
4588 if (GET_CODE (ad) == MEM)
4590 /* First ensure that the address in this MEM is valid. Then, unless
4591 indirect addresses are valid, reload the MEM into a register. */
4592 tem = ad;
4593 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
4594 opnum, ADDR_TYPE (type),
4595 ind_levels == 0 ? 0 : ind_levels - 1, insn);
4597 /* If tem was changed, then we must create a new memory reference to
4598 hold it and store it back into memrefloc. */
4599 if (tem != ad && memrefloc)
4601 *memrefloc = copy_rtx (*memrefloc);
4602 copy_replacements (tem, XEXP (*memrefloc, 0));
4603 loc = &XEXP (*memrefloc, 0);
4604 if (removed_and)
4605 loc = &XEXP (*loc, 0);
4608 /* Check similar cases as for indirect addresses as above except
4609 that we can allow pseudos and a MEM since they should have been
4610 taken care of above. */
4612 if (ind_levels == 0
4613 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
4614 || GET_CODE (XEXP (tem, 0)) == MEM
4615 || ! (GET_CODE (XEXP (tem, 0)) == REG
4616 || (GET_CODE (XEXP (tem, 0)) == PLUS
4617 && GET_CODE (XEXP (XEXP (tem, 0), 0)) == REG
4618 && GET_CODE (XEXP (XEXP (tem, 0), 1)) == CONST_INT)))
4620 /* Must use TEM here, not AD, since it is the one that will
4621 have any subexpressions reloaded, if needed. */
4622 push_reload (tem, NULL_RTX, loc, NULL_PTR,
4623 BASE_REG_CLASS, GET_MODE (tem),
4624 VOIDmode, 0,
4625 0, opnum, type);
4626 return ! removed_and;
4628 else
4629 return 0;
4632 /* If we have address of a stack slot but it's not valid because the
4633 displacement is too large, compute the sum in a register.
4634 Handle all base registers here, not just fp/ap/sp, because on some
4635 targets (namely SH) we can also get too large displacements from
4636 big-endian corrections. */
4637 else if (GET_CODE (ad) == PLUS
4638 && GET_CODE (XEXP (ad, 0)) == REG
4639 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
4640 && REG_MODE_OK_FOR_BASE_P (XEXP (ad, 0), mode)
4641 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
4643 /* Unshare the MEM rtx so we can safely alter it. */
4644 if (memrefloc)
4646 *memrefloc = copy_rtx (*memrefloc);
4647 loc = &XEXP (*memrefloc, 0);
4648 if (removed_and)
4649 loc = &XEXP (*loc, 0);
4652 if (double_reg_address_ok)
4654 /* Unshare the sum as well. */
4655 *loc = ad = copy_rtx (ad);
4657 /* Reload the displacement into an index reg.
4658 We assume the frame pointer or arg pointer is a base reg. */
4659 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
4660 INDEX_REG_CLASS, GET_MODE (ad), opnum,
4661 type, ind_levels);
4662 return 0;
4664 else
4666 /* If the sum of two regs is not necessarily valid,
4667 reload the sum into a base reg.
4668 That will at least work. */
4669 find_reloads_address_part (ad, loc, BASE_REG_CLASS,
4670 Pmode, opnum, type, ind_levels);
4672 return ! removed_and;
4675 /* If we have an indexed stack slot, there are three possible reasons why
4676 it might be invalid: The index might need to be reloaded, the address
4677 might have been made by frame pointer elimination and hence have a
4678 constant out of range, or both reasons might apply.
4680 We can easily check for an index needing reload, but even if that is the
4681 case, we might also have an invalid constant. To avoid making the
4682 conservative assumption and requiring two reloads, we see if this address
4683 is valid when not interpreted strictly. If it is, the only problem is
4684 that the index needs a reload and find_reloads_address_1 will take care
4685 of it.
4687 There is still a case when we might generate an extra reload,
4688 however. In certain cases eliminate_regs will return a MEM for a REG
4689 (see the code there for details). In those cases, memory_address_p
4690 applied to our address will return 0 so we will think that our offset
4691 must be too large. But it might indeed be valid and the only problem
4692 is that a MEM is present where a REG should be. This case should be
4693 very rare and there doesn't seem to be any way to avoid it.
4695 If we decide to do something here, it must be that
4696 `double_reg_address_ok' is true and that this address rtl was made by
4697 eliminate_regs. We generate a reload of the fp/sp/ap + constant and
4698 rework the sum so that the reload register will be added to the index.
4699 This is safe because we know the address isn't shared.
4701 We check for fp/ap/sp as both the first and second operand of the
4702 innermost PLUS. */
4704 else if (GET_CODE (ad) == PLUS && GET_CODE (XEXP (ad, 1)) == CONST_INT
4705 && GET_CODE (XEXP (ad, 0)) == PLUS
4706 && (XEXP (XEXP (ad, 0), 0) == frame_pointer_rtx
4707 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
4708 || XEXP (XEXP (ad, 0), 0) == hard_frame_pointer_rtx
4709 #endif
4710 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4711 || XEXP (XEXP (ad, 0), 0) == arg_pointer_rtx
4712 #endif
4713 || XEXP (XEXP (ad, 0), 0) == stack_pointer_rtx)
4714 && ! memory_address_p (mode, ad))
4716 *loc = ad = gen_rtx_PLUS (GET_MODE (ad),
4717 plus_constant (XEXP (XEXP (ad, 0), 0),
4718 INTVAL (XEXP (ad, 1))),
4719 XEXP (XEXP (ad, 0), 1));
4720 find_reloads_address_part (XEXP (ad, 0), &XEXP (ad, 0), BASE_REG_CLASS,
4721 GET_MODE (ad), opnum, type, ind_levels);
4722 find_reloads_address_1 (mode, XEXP (ad, 1), 1, &XEXP (ad, 1), opnum,
4723 type, 0, insn);
4725 return 0;
4728 else if (GET_CODE (ad) == PLUS && GET_CODE (XEXP (ad, 1)) == CONST_INT
4729 && GET_CODE (XEXP (ad, 0)) == PLUS
4730 && (XEXP (XEXP (ad, 0), 1) == frame_pointer_rtx
4731 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4732 || XEXP (XEXP (ad, 0), 1) == hard_frame_pointer_rtx
4733 #endif
4734 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4735 || XEXP (XEXP (ad, 0), 1) == arg_pointer_rtx
4736 #endif
4737 || XEXP (XEXP (ad, 0), 1) == stack_pointer_rtx)
4738 && ! memory_address_p (mode, ad))
4740 *loc = ad = gen_rtx_PLUS (GET_MODE (ad),
4741 XEXP (XEXP (ad, 0), 0),
4742 plus_constant (XEXP (XEXP (ad, 0), 1),
4743 INTVAL (XEXP (ad, 1))));
4744 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1), BASE_REG_CLASS,
4745 GET_MODE (ad), opnum, type, ind_levels);
4746 find_reloads_address_1 (mode, XEXP (ad, 0), 1, &XEXP (ad, 0), opnum,
4747 type, 0, insn);
4749 return 0;
4752 /* See if address becomes valid when an eliminable register
4753 in a sum is replaced. */
4755 tem = ad;
4756 if (GET_CODE (ad) == PLUS)
4757 tem = subst_indexed_address (ad);
4758 if (tem != ad && strict_memory_address_p (mode, tem))
4760 /* Ok, we win that way. Replace any additional eliminable
4761 registers. */
4763 subst_reg_equivs_changed = 0;
4764 tem = subst_reg_equivs (tem, insn);
4766 /* Make sure that didn't make the address invalid again. */
4768 if (! subst_reg_equivs_changed || strict_memory_address_p (mode, tem))
4770 *loc = tem;
4771 return 0;
4775 /* If constants aren't valid addresses, reload the constant address
4776 into a register. */
4777 if (CONSTANT_P (ad) && ! strict_memory_address_p (mode, ad))
4779 /* If AD is in address in the constant pool, the MEM rtx may be shared.
4780 Unshare it so we can safely alter it. */
4781 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
4782 && CONSTANT_POOL_ADDRESS_P (ad))
4784 *memrefloc = copy_rtx (*memrefloc);
4785 loc = &XEXP (*memrefloc, 0);
4786 if (removed_and)
4787 loc = &XEXP (*loc, 0);
4790 find_reloads_address_part (ad, loc, BASE_REG_CLASS, Pmode, opnum, type,
4791 ind_levels);
4792 return ! removed_and;
4795 return find_reloads_address_1 (mode, ad, 0, loc, opnum, type, ind_levels,
4796 insn);
4799 /* Find all pseudo regs appearing in AD
4800 that are eliminable in favor of equivalent values
4801 and do not have hard regs; replace them by their equivalents.
4802 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
4803 front of it for pseudos that we have to replace with stack slots. */
4805 static rtx
4806 subst_reg_equivs (ad, insn)
4807 rtx ad;
4808 rtx insn;
4810 register RTX_CODE code = GET_CODE (ad);
4811 register int i;
4812 register const char *fmt;
4814 switch (code)
4816 case HIGH:
4817 case CONST_INT:
4818 case CONST:
4819 case CONST_DOUBLE:
4820 case SYMBOL_REF:
4821 case LABEL_REF:
4822 case PC:
4823 case CC0:
4824 return ad;
4826 case REG:
4828 register int regno = REGNO (ad);
4830 if (reg_equiv_constant[regno] != 0)
4832 subst_reg_equivs_changed = 1;
4833 return reg_equiv_constant[regno];
4835 if (reg_equiv_memory_loc[regno] && num_not_at_initial_offset)
4837 rtx mem = make_memloc (ad, regno);
4838 if (! rtx_equal_p (mem, reg_equiv_mem[regno]))
4840 subst_reg_equivs_changed = 1;
4841 emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn);
4842 return mem;
4846 return ad;
4848 case PLUS:
4849 /* Quickly dispose of a common case. */
4850 if (XEXP (ad, 0) == frame_pointer_rtx
4851 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
4852 return ad;
4853 break;
4855 default:
4856 break;
4859 fmt = GET_RTX_FORMAT (code);
4860 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4861 if (fmt[i] == 'e')
4862 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
4863 return ad;
4866 /* Compute the sum of X and Y, making canonicalizations assumed in an
4867 address, namely: sum constant integers, surround the sum of two
4868 constants with a CONST, put the constant as the second operand, and
4869 group the constant on the outermost sum.
4871 This routine assumes both inputs are already in canonical form. */
4874 form_sum (x, y)
4875 rtx x, y;
4877 rtx tem;
4878 enum machine_mode mode = GET_MODE (x);
4880 if (mode == VOIDmode)
4881 mode = GET_MODE (y);
4883 if (mode == VOIDmode)
4884 mode = Pmode;
4886 if (GET_CODE (x) == CONST_INT)
4887 return plus_constant (y, INTVAL (x));
4888 else if (GET_CODE (y) == CONST_INT)
4889 return plus_constant (x, INTVAL (y));
4890 else if (CONSTANT_P (x))
4891 tem = x, x = y, y = tem;
4893 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
4894 return form_sum (XEXP (x, 0), form_sum (XEXP (x, 1), y));
4896 /* Note that if the operands of Y are specified in the opposite
4897 order in the recursive calls below, infinite recursion will occur. */
4898 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
4899 return form_sum (form_sum (x, XEXP (y, 0)), XEXP (y, 1));
4901 /* If both constant, encapsulate sum. Otherwise, just form sum. A
4902 constant will have been placed second. */
4903 if (CONSTANT_P (x) && CONSTANT_P (y))
4905 if (GET_CODE (x) == CONST)
4906 x = XEXP (x, 0);
4907 if (GET_CODE (y) == CONST)
4908 y = XEXP (y, 0);
4910 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
4913 return gen_rtx_PLUS (mode, x, y);
4916 /* If ADDR is a sum containing a pseudo register that should be
4917 replaced with a constant (from reg_equiv_constant),
4918 return the result of doing so, and also apply the associative
4919 law so that the result is more likely to be a valid address.
4920 (But it is not guaranteed to be one.)
4922 Note that at most one register is replaced, even if more are
4923 replaceable. Also, we try to put the result into a canonical form
4924 so it is more likely to be a valid address.
4926 In all other cases, return ADDR. */
4928 static rtx
4929 subst_indexed_address (addr)
4930 rtx addr;
4932 rtx op0 = 0, op1 = 0, op2 = 0;
4933 rtx tem;
4934 int regno;
4936 if (GET_CODE (addr) == PLUS)
4938 /* Try to find a register to replace. */
4939 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
4940 if (GET_CODE (op0) == REG
4941 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
4942 && reg_renumber[regno] < 0
4943 && reg_equiv_constant[regno] != 0)
4944 op0 = reg_equiv_constant[regno];
4945 else if (GET_CODE (op1) == REG
4946 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
4947 && reg_renumber[regno] < 0
4948 && reg_equiv_constant[regno] != 0)
4949 op1 = reg_equiv_constant[regno];
4950 else if (GET_CODE (op0) == PLUS
4951 && (tem = subst_indexed_address (op0)) != op0)
4952 op0 = tem;
4953 else if (GET_CODE (op1) == PLUS
4954 && (tem = subst_indexed_address (op1)) != op1)
4955 op1 = tem;
4956 else
4957 return addr;
4959 /* Pick out up to three things to add. */
4960 if (GET_CODE (op1) == PLUS)
4961 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
4962 else if (GET_CODE (op0) == PLUS)
4963 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
4965 /* Compute the sum. */
4966 if (op2 != 0)
4967 op1 = form_sum (op1, op2);
4968 if (op1 != 0)
4969 op0 = form_sum (op0, op1);
4971 return op0;
4973 return addr;
4976 /* Record the pseudo registers we must reload into hard registers in a
4977 subexpression of a would-be memory address, X referring to a value
4978 in mode MODE. (This function is not called if the address we find
4979 is strictly valid.)
4981 CONTEXT = 1 means we are considering regs as index regs,
4982 = 0 means we are considering them as base regs.
4984 OPNUM and TYPE specify the purpose of any reloads made.
4986 IND_LEVELS says how many levels of indirect addressing are
4987 supported at this point in the address.
4989 INSN, if nonzero, is the insn in which we do the reload. It is used
4990 to determine if we may generate output reloads.
4992 We return nonzero if X, as a whole, is reloaded or replaced. */
4994 /* Note that we take shortcuts assuming that no multi-reg machine mode
4995 occurs as part of an address.
4996 Also, this is not fully machine-customizable; it works for machines
4997 such as vaxes and 68000's and 32000's, but other possible machines
4998 could have addressing modes that this does not handle right. */
5000 static int
5001 find_reloads_address_1 (mode, x, context, loc, opnum, type, ind_levels, insn)
5002 enum machine_mode mode;
5003 rtx x;
5004 int context;
5005 rtx *loc;
5006 int opnum;
5007 enum reload_type type;
5008 int ind_levels;
5009 rtx insn;
5011 register RTX_CODE code = GET_CODE (x);
5013 switch (code)
5015 case PLUS:
5017 register rtx orig_op0 = XEXP (x, 0);
5018 register rtx orig_op1 = XEXP (x, 1);
5019 register RTX_CODE code0 = GET_CODE (orig_op0);
5020 register RTX_CODE code1 = GET_CODE (orig_op1);
5021 register rtx op0 = orig_op0;
5022 register rtx op1 = orig_op1;
5024 if (GET_CODE (op0) == SUBREG)
5026 op0 = SUBREG_REG (op0);
5027 code0 = GET_CODE (op0);
5028 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5029 op0 = gen_rtx_REG (word_mode,
5030 REGNO (op0) + SUBREG_WORD (orig_op0));
5033 if (GET_CODE (op1) == SUBREG)
5035 op1 = SUBREG_REG (op1);
5036 code1 = GET_CODE (op1);
5037 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5038 op1 = gen_rtx_REG (GET_MODE (op1),
5039 REGNO (op1) + SUBREG_WORD (orig_op1));
5042 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
5043 || code0 == ZERO_EXTEND || code1 == MEM)
5045 find_reloads_address_1 (mode, orig_op0, 1, &XEXP (x, 0), opnum,
5046 type, ind_levels, insn);
5047 find_reloads_address_1 (mode, orig_op1, 0, &XEXP (x, 1), opnum,
5048 type, ind_levels, insn);
5051 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
5052 || code1 == ZERO_EXTEND || code0 == MEM)
5054 find_reloads_address_1 (mode, orig_op0, 0, &XEXP (x, 0), opnum,
5055 type, ind_levels, insn);
5056 find_reloads_address_1 (mode, orig_op1, 1, &XEXP (x, 1), opnum,
5057 type, ind_levels, insn);
5060 else if (code0 == CONST_INT || code0 == CONST
5061 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5062 find_reloads_address_1 (mode, orig_op1, 0, &XEXP (x, 1), opnum,
5063 type, ind_levels, insn);
5065 else if (code1 == CONST_INT || code1 == CONST
5066 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5067 find_reloads_address_1 (mode, orig_op0, 0, &XEXP (x, 0), opnum,
5068 type, ind_levels, insn);
5070 else if (code0 == REG && code1 == REG)
5072 if (REG_OK_FOR_INDEX_P (op0)
5073 && REG_MODE_OK_FOR_BASE_P (op1, mode))
5074 return 0;
5075 else if (REG_OK_FOR_INDEX_P (op1)
5076 && REG_MODE_OK_FOR_BASE_P (op0, mode))
5077 return 0;
5078 else if (REG_MODE_OK_FOR_BASE_P (op1, mode))
5079 find_reloads_address_1 (mode, orig_op0, 1, &XEXP (x, 0), opnum,
5080 type, ind_levels, insn);
5081 else if (REG_MODE_OK_FOR_BASE_P (op0, mode))
5082 find_reloads_address_1 (mode, orig_op1, 1, &XEXP (x, 1), opnum,
5083 type, ind_levels, insn);
5084 else if (REG_OK_FOR_INDEX_P (op1))
5085 find_reloads_address_1 (mode, orig_op0, 0, &XEXP (x, 0), opnum,
5086 type, ind_levels, insn);
5087 else if (REG_OK_FOR_INDEX_P (op0))
5088 find_reloads_address_1 (mode, orig_op1, 0, &XEXP (x, 1), opnum,
5089 type, ind_levels, insn);
5090 else
5092 find_reloads_address_1 (mode, orig_op0, 1, &XEXP (x, 0), opnum,
5093 type, ind_levels, insn);
5094 find_reloads_address_1 (mode, orig_op1, 0, &XEXP (x, 1), opnum,
5095 type, ind_levels, insn);
5099 else if (code0 == REG)
5101 find_reloads_address_1 (mode, orig_op0, 1, &XEXP (x, 0), opnum,
5102 type, ind_levels, insn);
5103 find_reloads_address_1 (mode, orig_op1, 0, &XEXP (x, 1), opnum,
5104 type, ind_levels, insn);
5107 else if (code1 == REG)
5109 find_reloads_address_1 (mode, orig_op1, 1, &XEXP (x, 1), opnum,
5110 type, ind_levels, insn);
5111 find_reloads_address_1 (mode, orig_op0, 0, &XEXP (x, 0), opnum,
5112 type, ind_levels, insn);
5116 return 0;
5118 case POST_INC:
5119 case POST_DEC:
5120 case PRE_INC:
5121 case PRE_DEC:
5122 if (GET_CODE (XEXP (x, 0)) == REG)
5124 register int regno = REGNO (XEXP (x, 0));
5125 int value = 0;
5126 rtx x_orig = x;
5128 /* A register that is incremented cannot be constant! */
5129 if (regno >= FIRST_PSEUDO_REGISTER
5130 && reg_equiv_constant[regno] != 0)
5131 abort ();
5133 /* Handle a register that is equivalent to a memory location
5134 which cannot be addressed directly. */
5135 if (reg_equiv_memory_loc[regno] != 0
5136 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5138 rtx tem = make_memloc (XEXP (x, 0), regno);
5139 if (reg_equiv_address[regno]
5140 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5142 /* First reload the memory location's address.
5143 We can't use ADDR_TYPE (type) here, because we need to
5144 write back the value after reading it, hence we actually
5145 need two registers. */
5146 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5147 &XEXP (tem, 0), opnum, type,
5148 ind_levels, insn);
5149 /* Put this inside a new increment-expression. */
5150 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5151 /* Proceed to reload that, as if it contained a register. */
5155 /* If we have a hard register that is ok as an index,
5156 don't make a reload. If an autoincrement of a nice register
5157 isn't "valid", it must be that no autoincrement is "valid".
5158 If that is true and something made an autoincrement anyway,
5159 this must be a special context where one is allowed.
5160 (For example, a "push" instruction.)
5161 We can't improve this address, so leave it alone. */
5163 /* Otherwise, reload the autoincrement into a suitable hard reg
5164 and record how much to increment by. */
5166 if (reg_renumber[regno] >= 0)
5167 regno = reg_renumber[regno];
5168 if ((regno >= FIRST_PSEUDO_REGISTER
5169 || !(context ? REGNO_OK_FOR_INDEX_P (regno)
5170 : REGNO_MODE_OK_FOR_BASE_P (regno, mode))))
5172 #ifdef AUTO_INC_DEC
5173 register rtx link;
5174 #endif
5175 int reloadnum;
5177 /* If we can output the register afterwards, do so, this
5178 saves the extra update.
5179 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5180 CALL_INSN - and it does not set CC0.
5181 But don't do this if we cannot directly address the
5182 memory location, since this will make it harder to
5183 reuse address reloads, and increases register pressure.
5184 Also don't do this if we can probably update x directly. */
5185 rtx equiv = (GET_CODE (XEXP (x, 0)) == MEM
5186 ? XEXP (x, 0)
5187 : reg_equiv_mem[regno]);
5188 int icode = (int) add_optab->handlers[(int) Pmode].insn_code;
5189 if (insn && GET_CODE (insn) == INSN && equiv
5190 && memory_operand (equiv, GET_MODE (equiv))
5191 #ifdef HAVE_cc0
5192 && ! sets_cc0_p (PATTERN (insn))
5193 #endif
5194 && ! (icode != CODE_FOR_nothing
5195 && ((*insn_data[icode].operand[0].predicate)
5196 (equiv, Pmode))
5197 && ((*insn_data[icode].operand[1].predicate)
5198 (equiv, Pmode))))
5200 loc = &XEXP (x, 0);
5201 x = XEXP (x, 0);
5202 reloadnum
5203 = push_reload (x, x, loc, loc,
5204 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5205 GET_MODE (x), GET_MODE (x), 0, 0,
5206 opnum, RELOAD_OTHER);
5208 /* If we created a new MEM based on reg_equiv_mem[REGNO], then
5209 LOC above is part of the new MEM, not the MEM in INSN.
5211 We must also replace the address of the MEM in INSN. */
5212 if (&XEXP (x_orig, 0) != loc)
5213 push_replacement (&XEXP (x_orig, 0), reloadnum, VOIDmode);
5216 else
5218 reloadnum
5219 = push_reload (x, NULL_RTX, loc, NULL_PTR,
5220 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5221 GET_MODE (x), GET_MODE (x), 0, 0,
5222 opnum, type);
5223 rld[reloadnum].inc
5224 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5226 value = 1;
5229 #ifdef AUTO_INC_DEC
5230 /* Update the REG_INC notes. */
5232 for (link = REG_NOTES (this_insn);
5233 link; link = XEXP (link, 1))
5234 if (REG_NOTE_KIND (link) == REG_INC
5235 && REGNO (XEXP (link, 0)) == REGNO (XEXP (x_orig, 0)))
5236 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5237 #endif
5239 return value;
5242 else if (GET_CODE (XEXP (x, 0)) == MEM)
5244 /* This is probably the result of a substitution, by eliminate_regs,
5245 of an equivalent address for a pseudo that was not allocated to a
5246 hard register. Verify that the specified address is valid and
5247 reload it into a register. */
5248 /* Variable `tem' might or might not be used in FIND_REG_INC_NOTE. */
5249 rtx tem ATTRIBUTE_UNUSED = XEXP (x, 0);
5250 register rtx link;
5251 int reloadnum;
5253 /* Since we know we are going to reload this item, don't decrement
5254 for the indirection level.
5256 Note that this is actually conservative: it would be slightly
5257 more efficient to use the value of SPILL_INDIRECT_LEVELS from
5258 reload1.c here. */
5259 /* We can't use ADDR_TYPE (type) here, because we need to
5260 write back the value after reading it, hence we actually
5261 need two registers. */
5262 find_reloads_address (GET_MODE (x), &XEXP (x, 0),
5263 XEXP (XEXP (x, 0), 0), &XEXP (XEXP (x, 0), 0),
5264 opnum, type, ind_levels, insn);
5266 reloadnum = push_reload (x, NULL_RTX, loc, NULL_PTR,
5267 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5268 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5269 rld[reloadnum].inc
5270 = find_inc_amount (PATTERN (this_insn), XEXP (x, 0));
5272 link = FIND_REG_INC_NOTE (this_insn, tem);
5273 if (link != 0)
5274 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5276 return 1;
5278 return 0;
5280 case MEM:
5281 /* This is probably the result of a substitution, by eliminate_regs, of
5282 an equivalent address for a pseudo that was not allocated to a hard
5283 register. Verify that the specified address is valid and reload it
5284 into a register.
5286 Since we know we are going to reload this item, don't decrement for
5287 the indirection level.
5289 Note that this is actually conservative: it would be slightly more
5290 efficient to use the value of SPILL_INDIRECT_LEVELS from
5291 reload1.c here. */
5293 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5294 opnum, ADDR_TYPE (type), ind_levels, insn);
5295 push_reload (*loc, NULL_RTX, loc, NULL_PTR,
5296 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5297 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5298 return 1;
5300 case REG:
5302 register int regno = REGNO (x);
5304 if (reg_equiv_constant[regno] != 0)
5306 find_reloads_address_part (reg_equiv_constant[regno], loc,
5307 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5308 GET_MODE (x), opnum, type, ind_levels);
5309 return 1;
5312 #if 0 /* This might screw code in reload1.c to delete prior output-reload
5313 that feeds this insn. */
5314 if (reg_equiv_mem[regno] != 0)
5316 push_reload (reg_equiv_mem[regno], NULL_RTX, loc, NULL_PTR,
5317 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5318 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5319 return 1;
5321 #endif
5323 if (reg_equiv_memory_loc[regno]
5324 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5326 rtx tem = make_memloc (x, regno);
5327 if (reg_equiv_address[regno] != 0
5328 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5330 x = tem;
5331 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5332 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5333 ind_levels, insn);
5337 if (reg_renumber[regno] >= 0)
5338 regno = reg_renumber[regno];
5340 if ((regno >= FIRST_PSEUDO_REGISTER
5341 || !(context ? REGNO_OK_FOR_INDEX_P (regno)
5342 : REGNO_MODE_OK_FOR_BASE_P (regno, mode))))
5344 push_reload (x, NULL_RTX, loc, NULL_PTR,
5345 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5346 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5347 return 1;
5350 /* If a register appearing in an address is the subject of a CLOBBER
5351 in this insn, reload it into some other register to be safe.
5352 The CLOBBER is supposed to make the register unavailable
5353 from before this insn to after it. */
5354 if (regno_clobbered_p (regno, this_insn))
5356 push_reload (x, NULL_RTX, loc, NULL_PTR,
5357 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5358 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5359 return 1;
5362 return 0;
5364 case SUBREG:
5365 if (GET_CODE (SUBREG_REG (x)) == REG)
5367 /* If this is a SUBREG of a hard register and the resulting register
5368 is of the wrong class, reload the whole SUBREG. This avoids
5369 needless copies if SUBREG_REG is multi-word. */
5370 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5372 int regno = REGNO (SUBREG_REG (x)) + SUBREG_WORD (x);
5374 if (! (context ? REGNO_OK_FOR_INDEX_P (regno)
5375 : REGNO_MODE_OK_FOR_BASE_P (regno, mode)))
5377 push_reload (x, NULL_RTX, loc, NULL_PTR,
5378 (context ? INDEX_REG_CLASS : BASE_REG_CLASS),
5379 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5380 return 1;
5383 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
5384 is larger than the class size, then reload the whole SUBREG. */
5385 else
5387 enum reg_class class = (context ? INDEX_REG_CLASS
5388 : BASE_REG_CLASS);
5389 if (CLASS_MAX_NREGS (class, GET_MODE (SUBREG_REG (x)))
5390 > reg_class_size[class])
5392 x = find_reloads_subreg_address (x, 0, opnum, type,
5393 ind_levels, insn);
5394 push_reload (x, NULL_RTX, loc, NULL_PTR, class,
5395 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5396 return 1;
5400 break;
5402 default:
5403 break;
5407 register const char *fmt = GET_RTX_FORMAT (code);
5408 register int i;
5410 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5412 if (fmt[i] == 'e')
5413 find_reloads_address_1 (mode, XEXP (x, i), context, &XEXP (x, i),
5414 opnum, type, ind_levels, insn);
5418 return 0;
5421 /* X, which is found at *LOC, is a part of an address that needs to be
5422 reloaded into a register of class CLASS. If X is a constant, or if
5423 X is a PLUS that contains a constant, check that the constant is a
5424 legitimate operand and that we are supposed to be able to load
5425 it into the register.
5427 If not, force the constant into memory and reload the MEM instead.
5429 MODE is the mode to use, in case X is an integer constant.
5431 OPNUM and TYPE describe the purpose of any reloads made.
5433 IND_LEVELS says how many levels of indirect addressing this machine
5434 supports. */
5436 static void
5437 find_reloads_address_part (x, loc, class, mode, opnum, type, ind_levels)
5438 rtx x;
5439 rtx *loc;
5440 enum reg_class class;
5441 enum machine_mode mode;
5442 int opnum;
5443 enum reload_type type;
5444 int ind_levels;
5446 if (CONSTANT_P (x)
5447 && (! LEGITIMATE_CONSTANT_P (x)
5448 || PREFERRED_RELOAD_CLASS (x, class) == NO_REGS))
5450 rtx tem;
5452 /* If this is a CONST_INT, it could have been created by a
5453 plus_constant call in eliminate_regs, which means it may be
5454 on the reload_obstack. reload_obstack will be freed later, so
5455 we can't allow such RTL to be put in the constant pool. There
5456 is code in force_const_mem to check for this case, but it doesn't
5457 work because we have already popped off the reload_obstack, so
5458 rtl_obstack == saveable_obstack is true at this point. */
5459 if (GET_CODE (x) == CONST_INT)
5460 tem = x = force_const_mem (mode, GEN_INT (INTVAL (x)));
5461 else
5462 tem = x = force_const_mem (mode, x);
5464 find_reloads_address (mode, &tem, XEXP (tem, 0), &XEXP (tem, 0),
5465 opnum, type, ind_levels, 0);
5468 else if (GET_CODE (x) == PLUS
5469 && CONSTANT_P (XEXP (x, 1))
5470 && (! LEGITIMATE_CONSTANT_P (XEXP (x, 1))
5471 || PREFERRED_RELOAD_CLASS (XEXP (x, 1), class) == NO_REGS))
5473 rtx tem;
5475 /* See comment above. */
5476 if (GET_CODE (XEXP (x, 1)) == CONST_INT)
5477 tem = force_const_mem (GET_MODE (x), GEN_INT (INTVAL (XEXP (x, 1))));
5478 else
5479 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
5481 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
5482 find_reloads_address (mode, &tem, XEXP (tem, 0), &XEXP (tem, 0),
5483 opnum, type, ind_levels, 0);
5486 push_reload (x, NULL_RTX, loc, NULL_PTR, class,
5487 mode, VOIDmode, 0, 0, opnum, type);
5490 /* X, a subreg of a pseudo, is a part of an address that needs to be
5491 reloaded.
5493 If the pseudo is equivalent to a memory location that cannot be directly
5494 addressed, make the necessary address reloads.
5496 If address reloads have been necessary, or if the address is changed
5497 by register elimination, return the rtx of the memory location;
5498 otherwise, return X.
5500 If FORCE_REPLACE is nonzero, unconditionally replace the subreg with the
5501 memory location.
5503 OPNUM and TYPE identify the purpose of the reload.
5505 IND_LEVELS says how many levels of indirect addressing are
5506 supported at this point in the address.
5508 INSN, if nonzero, is the insn in which we do the reload. It is used
5509 to determine where to put USEs for pseudos that we have to replace with
5510 stack slots. */
5512 static rtx
5513 find_reloads_subreg_address (x, force_replace, opnum, type,
5514 ind_levels, insn)
5515 rtx x;
5516 int force_replace;
5517 int opnum;
5518 enum reload_type type;
5519 int ind_levels;
5520 rtx insn;
5522 int regno = REGNO (SUBREG_REG (x));
5524 if (reg_equiv_memory_loc[regno])
5526 /* If the address is not directly addressable, or if the address is not
5527 offsettable, then it must be replaced. */
5528 if (! force_replace
5529 && (reg_equiv_address[regno]
5530 || ! offsettable_memref_p (reg_equiv_mem[regno])))
5531 force_replace = 1;
5533 if (force_replace || num_not_at_initial_offset)
5535 rtx tem = make_memloc (SUBREG_REG (x), regno);
5537 /* If the address changes because of register elimination, then
5538 it must be replaced. */
5539 if (force_replace
5540 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5542 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
5544 if (BYTES_BIG_ENDIAN)
5546 int size;
5548 size = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
5549 offset += MIN (size, UNITS_PER_WORD);
5550 size = GET_MODE_SIZE (GET_MODE (x));
5551 offset -= MIN (size, UNITS_PER_WORD);
5553 XEXP (tem, 0) = plus_constant (XEXP (tem, 0), offset);
5554 PUT_MODE (tem, GET_MODE (x));
5555 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5556 &XEXP (tem, 0), opnum, ADDR_TYPE (type),
5557 ind_levels, insn);
5558 /* If this is not a toplevel operand, find_reloads doesn't see
5559 this substitution. We have to emit a USE of the pseudo so
5560 that delete_output_reload can see it. */
5561 if (replace_reloads && recog_data.operand[opnum] != x)
5562 emit_insn_before (gen_rtx_USE (VOIDmode, SUBREG_REG (x)), insn);
5563 x = tem;
5567 return x;
5570 /* Substitute into the current INSN the registers into which we have reloaded
5571 the things that need reloading. The array `replacements'
5572 says contains the locations of all pointers that must be changed
5573 and says what to replace them with.
5575 Return the rtx that X translates into; usually X, but modified. */
5577 void
5578 subst_reloads ()
5580 register int i;
5582 for (i = 0; i < n_replacements; i++)
5584 register struct replacement *r = &replacements[i];
5585 register rtx reloadreg = rld[r->what].reg_rtx;
5586 if (reloadreg)
5588 /* Encapsulate RELOADREG so its machine mode matches what
5589 used to be there. Note that gen_lowpart_common will
5590 do the wrong thing if RELOADREG is multi-word. RELOADREG
5591 will always be a REG here. */
5592 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
5593 reloadreg = gen_rtx_REG (r->mode, REGNO (reloadreg));
5595 /* If we are putting this into a SUBREG and RELOADREG is a
5596 SUBREG, we would be making nested SUBREGs, so we have to fix
5597 this up. Note that r->where == &SUBREG_REG (*r->subreg_loc). */
5599 if (r->subreg_loc != 0 && GET_CODE (reloadreg) == SUBREG)
5601 if (GET_MODE (*r->subreg_loc)
5602 == GET_MODE (SUBREG_REG (reloadreg)))
5603 *r->subreg_loc = SUBREG_REG (reloadreg);
5604 else
5606 *r->where = SUBREG_REG (reloadreg);
5607 SUBREG_WORD (*r->subreg_loc) += SUBREG_WORD (reloadreg);
5610 else
5611 *r->where = reloadreg;
5613 /* If reload got no reg and isn't optional, something's wrong. */
5614 else if (! rld[r->what].optional)
5615 abort ();
5619 /* Make a copy of any replacements being done into X and move those copies
5620 to locations in Y, a copy of X. We only look at the highest level of
5621 the RTL. */
5623 void
5624 copy_replacements (x, y)
5625 rtx x;
5626 rtx y;
5628 int i, j;
5629 enum rtx_code code = GET_CODE (x);
5630 const char *fmt = GET_RTX_FORMAT (code);
5631 struct replacement *r;
5633 /* We can't support X being a SUBREG because we might then need to know its
5634 location if something inside it was replaced. */
5635 if (code == SUBREG)
5636 abort ();
5638 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5639 if (fmt[i] == 'e')
5640 for (j = 0; j < n_replacements; j++)
5642 if (replacements[j].subreg_loc == &XEXP (x, i))
5644 r = &replacements[n_replacements++];
5645 r->where = replacements[j].where;
5646 r->subreg_loc = &XEXP (y, i);
5647 r->what = replacements[j].what;
5648 r->mode = replacements[j].mode;
5650 else if (replacements[j].where == &XEXP (x, i))
5652 r = &replacements[n_replacements++];
5653 r->where = &XEXP (y, i);
5654 r->subreg_loc = 0;
5655 r->what = replacements[j].what;
5656 r->mode = replacements[j].mode;
5661 /* Change any replacements being done to *X to be done to *Y */
5663 void
5664 move_replacements (x, y)
5665 rtx *x;
5666 rtx *y;
5668 int i;
5670 for (i = 0; i < n_replacements; i++)
5671 if (replacements[i].subreg_loc == x)
5672 replacements[i].subreg_loc = y;
5673 else if (replacements[i].where == x)
5675 replacements[i].where = y;
5676 replacements[i].subreg_loc = 0;
5680 /* If LOC was scheduled to be replaced by something, return the replacement.
5681 Otherwise, return *LOC. */
5684 find_replacement (loc)
5685 rtx *loc;
5687 struct replacement *r;
5689 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
5691 rtx reloadreg = rld[r->what].reg_rtx;
5693 if (reloadreg && r->where == loc)
5695 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
5696 reloadreg = gen_rtx_REG (r->mode, REGNO (reloadreg));
5698 return reloadreg;
5700 else if (reloadreg && r->subreg_loc == loc)
5702 /* RELOADREG must be either a REG or a SUBREG.
5704 ??? Is it actually still ever a SUBREG? If so, why? */
5706 if (GET_CODE (reloadreg) == REG)
5707 return gen_rtx_REG (GET_MODE (*loc),
5708 REGNO (reloadreg) + SUBREG_WORD (*loc));
5709 else if (GET_MODE (reloadreg) == GET_MODE (*loc))
5710 return reloadreg;
5711 else
5712 return gen_rtx_SUBREG (GET_MODE (*loc), SUBREG_REG (reloadreg),
5713 SUBREG_WORD (reloadreg) + SUBREG_WORD (*loc));
5717 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
5718 what's inside and make a new rtl if so. */
5719 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
5720 || GET_CODE (*loc) == MULT)
5722 rtx x = find_replacement (&XEXP (*loc, 0));
5723 rtx y = find_replacement (&XEXP (*loc, 1));
5725 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
5726 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
5729 return *loc;
5732 /* Return nonzero if register in range [REGNO, ENDREGNO)
5733 appears either explicitly or implicitly in X
5734 other than being stored into (except for earlyclobber operands).
5736 References contained within the substructure at LOC do not count.
5737 LOC may be zero, meaning don't ignore anything.
5739 This is similar to refers_to_regno_p in rtlanal.c except that we
5740 look at equivalences for pseudos that didn't get hard registers. */
5743 refers_to_regno_for_reload_p (regno, endregno, x, loc)
5744 int regno, endregno;
5745 rtx x;
5746 rtx *loc;
5748 register int i;
5749 register RTX_CODE code;
5750 register const char *fmt;
5752 if (x == 0)
5753 return 0;
5755 repeat:
5756 code = GET_CODE (x);
5758 switch (code)
5760 case REG:
5761 i = REGNO (x);
5763 /* If this is a pseudo, a hard register must not have been allocated.
5764 X must therefore either be a constant or be in memory. */
5765 if (i >= FIRST_PSEUDO_REGISTER)
5767 if (reg_equiv_memory_loc[i])
5768 return refers_to_regno_for_reload_p (regno, endregno,
5769 reg_equiv_memory_loc[i],
5770 NULL_PTR);
5772 if (reg_equiv_constant[i])
5773 return 0;
5775 abort ();
5778 return (endregno > i
5779 && regno < i + (i < FIRST_PSEUDO_REGISTER
5780 ? HARD_REGNO_NREGS (i, GET_MODE (x))
5781 : 1));
5783 case SUBREG:
5784 /* If this is a SUBREG of a hard reg, we can see exactly which
5785 registers are being modified. Otherwise, handle normally. */
5786 if (GET_CODE (SUBREG_REG (x)) == REG
5787 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5789 int inner_regno = REGNO (SUBREG_REG (x)) + SUBREG_WORD (x);
5790 int inner_endregno
5791 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
5792 ? HARD_REGNO_NREGS (regno, GET_MODE (x)) : 1);
5794 return endregno > inner_regno && regno < inner_endregno;
5796 break;
5798 case CLOBBER:
5799 case SET:
5800 if (&SET_DEST (x) != loc
5801 /* Note setting a SUBREG counts as referring to the REG it is in for
5802 a pseudo but not for hard registers since we can
5803 treat each word individually. */
5804 && ((GET_CODE (SET_DEST (x)) == SUBREG
5805 && loc != &SUBREG_REG (SET_DEST (x))
5806 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG
5807 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
5808 && refers_to_regno_for_reload_p (regno, endregno,
5809 SUBREG_REG (SET_DEST (x)),
5810 loc))
5811 /* If the output is an earlyclobber operand, this is
5812 a conflict. */
5813 || ((GET_CODE (SET_DEST (x)) != REG
5814 || earlyclobber_operand_p (SET_DEST (x)))
5815 && refers_to_regno_for_reload_p (regno, endregno,
5816 SET_DEST (x), loc))))
5817 return 1;
5819 if (code == CLOBBER || loc == &SET_SRC (x))
5820 return 0;
5821 x = SET_SRC (x);
5822 goto repeat;
5824 default:
5825 break;
5828 /* X does not match, so try its subexpressions. */
5830 fmt = GET_RTX_FORMAT (code);
5831 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5833 if (fmt[i] == 'e' && loc != &XEXP (x, i))
5835 if (i == 0)
5837 x = XEXP (x, 0);
5838 goto repeat;
5840 else
5841 if (refers_to_regno_for_reload_p (regno, endregno,
5842 XEXP (x, i), loc))
5843 return 1;
5845 else if (fmt[i] == 'E')
5847 register int j;
5848 for (j = XVECLEN (x, i) - 1; j >=0; j--)
5849 if (loc != &XVECEXP (x, i, j)
5850 && refers_to_regno_for_reload_p (regno, endregno,
5851 XVECEXP (x, i, j), loc))
5852 return 1;
5855 return 0;
5858 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
5859 we check if any register number in X conflicts with the relevant register
5860 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
5861 contains a MEM (we don't bother checking for memory addresses that can't
5862 conflict because we expect this to be a rare case.
5864 This function is similar to reg_overlap_mention_p in rtlanal.c except
5865 that we look at equivalences for pseudos that didn't get hard registers. */
5868 reg_overlap_mentioned_for_reload_p (x, in)
5869 rtx x, in;
5871 int regno, endregno;
5873 /* Overly conservative. */
5874 if (GET_CODE (x) == STRICT_LOW_PART)
5875 x = XEXP (x, 0);
5877 /* If either argument is a constant, then modifying X can not affect IN. */
5878 if (CONSTANT_P (x) || CONSTANT_P (in))
5879 return 0;
5880 else if (GET_CODE (x) == SUBREG)
5882 regno = REGNO (SUBREG_REG (x));
5883 if (regno < FIRST_PSEUDO_REGISTER)
5884 regno += SUBREG_WORD (x);
5886 else if (GET_CODE (x) == REG)
5888 regno = REGNO (x);
5890 /* If this is a pseudo, it must not have been assigned a hard register.
5891 Therefore, it must either be in memory or be a constant. */
5893 if (regno >= FIRST_PSEUDO_REGISTER)
5895 if (reg_equiv_memory_loc[regno])
5896 return refers_to_mem_for_reload_p (in);
5897 else if (reg_equiv_constant[regno])
5898 return 0;
5899 abort ();
5902 else if (GET_CODE (x) == MEM)
5903 return refers_to_mem_for_reload_p (in);
5904 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
5905 || GET_CODE (x) == CC0)
5906 return reg_mentioned_p (x, in);
5907 else
5908 abort ();
5910 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
5911 ? HARD_REGNO_NREGS (regno, GET_MODE (x)) : 1);
5913 return refers_to_regno_for_reload_p (regno, endregno, in, NULL_PTR);
5916 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
5917 registers. */
5920 refers_to_mem_for_reload_p (x)
5921 rtx x;
5923 const char *fmt;
5924 int i;
5926 if (GET_CODE (x) == MEM)
5927 return 1;
5929 if (GET_CODE (x) == REG)
5930 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
5931 && reg_equiv_memory_loc[REGNO (x)]);
5933 fmt = GET_RTX_FORMAT (GET_CODE (x));
5934 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
5935 if (fmt[i] == 'e'
5936 && (GET_CODE (XEXP (x, i)) == MEM
5937 || refers_to_mem_for_reload_p (XEXP (x, i))))
5938 return 1;
5940 return 0;
5943 /* Check the insns before INSN to see if there is a suitable register
5944 containing the same value as GOAL.
5945 If OTHER is -1, look for a register in class CLASS.
5946 Otherwise, just see if register number OTHER shares GOAL's value.
5948 Return an rtx for the register found, or zero if none is found.
5950 If RELOAD_REG_P is (short *)1,
5951 we reject any hard reg that appears in reload_reg_rtx
5952 because such a hard reg is also needed coming into this insn.
5954 If RELOAD_REG_P is any other nonzero value,
5955 it is a vector indexed by hard reg number
5956 and we reject any hard reg whose element in the vector is nonnegative
5957 as well as any that appears in reload_reg_rtx.
5959 If GOAL is zero, then GOALREG is a register number; we look
5960 for an equivalent for that register.
5962 MODE is the machine mode of the value we want an equivalence for.
5963 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
5965 This function is used by jump.c as well as in the reload pass.
5967 If GOAL is the sum of the stack pointer and a constant, we treat it
5968 as if it were a constant except that sp is required to be unchanging. */
5971 find_equiv_reg (goal, insn, class, other, reload_reg_p, goalreg, mode)
5972 register rtx goal;
5973 rtx insn;
5974 enum reg_class class;
5975 register int other;
5976 short *reload_reg_p;
5977 int goalreg;
5978 enum machine_mode mode;
5980 register rtx p = insn;
5981 rtx goaltry, valtry, value, where;
5982 register rtx pat;
5983 register int regno = -1;
5984 int valueno;
5985 int goal_mem = 0;
5986 int goal_const = 0;
5987 int goal_mem_addr_varies = 0;
5988 int need_stable_sp = 0;
5989 int nregs;
5990 int valuenregs;
5992 if (goal == 0)
5993 regno = goalreg;
5994 else if (GET_CODE (goal) == REG)
5995 regno = REGNO (goal);
5996 else if (GET_CODE (goal) == MEM)
5998 enum rtx_code code = GET_CODE (XEXP (goal, 0));
5999 if (MEM_VOLATILE_P (goal))
6000 return 0;
6001 if (flag_float_store && GET_MODE_CLASS (GET_MODE (goal)) == MODE_FLOAT)
6002 return 0;
6003 /* An address with side effects must be reexecuted. */
6004 switch (code)
6006 case POST_INC:
6007 case PRE_INC:
6008 case POST_DEC:
6009 case PRE_DEC:
6010 return 0;
6011 default:
6012 break;
6014 goal_mem = 1;
6016 else if (CONSTANT_P (goal))
6017 goal_const = 1;
6018 else if (GET_CODE (goal) == PLUS
6019 && XEXP (goal, 0) == stack_pointer_rtx
6020 && CONSTANT_P (XEXP (goal, 1)))
6021 goal_const = need_stable_sp = 1;
6022 else if (GET_CODE (goal) == PLUS
6023 && XEXP (goal, 0) == frame_pointer_rtx
6024 && CONSTANT_P (XEXP (goal, 1)))
6025 goal_const = 1;
6026 else
6027 return 0;
6029 /* On some machines, certain regs must always be rejected
6030 because they don't behave the way ordinary registers do. */
6032 #ifdef OVERLAPPING_REGNO_P
6033 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER
6034 && OVERLAPPING_REGNO_P (regno))
6035 return 0;
6036 #endif
6038 /* Scan insns back from INSN, looking for one that copies
6039 a value into or out of GOAL.
6040 Stop and give up if we reach a label. */
6042 while (1)
6044 p = PREV_INSN (p);
6045 if (p == 0 || GET_CODE (p) == CODE_LABEL)
6046 return 0;
6047 if (GET_CODE (p) == INSN
6048 /* If we don't want spill regs ... */
6049 && (! (reload_reg_p != 0
6050 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6051 /* ... then ignore insns introduced by reload; they aren't useful
6052 and can cause results in reload_as_needed to be different
6053 from what they were when calculating the need for spills.
6054 If we notice an input-reload insn here, we will reject it below,
6055 but it might hide a usable equivalent. That makes bad code.
6056 It may even abort: perhaps no reg was spilled for this insn
6057 because it was assumed we would find that equivalent. */
6058 || INSN_UID (p) < reload_first_uid))
6060 rtx tem;
6061 pat = single_set (p);
6062 /* First check for something that sets some reg equal to GOAL. */
6063 if (pat != 0
6064 && ((regno >= 0
6065 && true_regnum (SET_SRC (pat)) == regno
6066 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6068 (regno >= 0
6069 && true_regnum (SET_DEST (pat)) == regno
6070 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6072 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6073 /* When looking for stack pointer + const,
6074 make sure we don't use a stack adjust. */
6075 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6076 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6077 || (goal_mem
6078 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6079 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6080 || (goal_mem
6081 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6082 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6083 /* If we are looking for a constant,
6084 and something equivalent to that constant was copied
6085 into a reg, we can use that reg. */
6086 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6087 NULL_RTX))
6088 && rtx_equal_p (XEXP (tem, 0), goal)
6089 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6090 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6091 NULL_RTX))
6092 && GET_CODE (SET_DEST (pat)) == REG
6093 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6094 && GET_MODE_CLASS (GET_MODE (XEXP (tem, 0))) == MODE_FLOAT
6095 && GET_CODE (goal) == CONST_INT
6096 && 0 != (goaltry = operand_subword (XEXP (tem, 0), 0, 0,
6097 VOIDmode))
6098 && rtx_equal_p (goal, goaltry)
6099 && (valtry = operand_subword (SET_DEST (pat), 0, 0,
6100 VOIDmode))
6101 && (valueno = true_regnum (valtry)) >= 0)
6102 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6103 NULL_RTX))
6104 && GET_CODE (SET_DEST (pat)) == REG
6105 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6106 && GET_MODE_CLASS (GET_MODE (XEXP (tem, 0))) == MODE_FLOAT
6107 && GET_CODE (goal) == CONST_INT
6108 && 0 != (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6109 VOIDmode))
6110 && rtx_equal_p (goal, goaltry)
6111 && (valtry
6112 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6113 && (valueno = true_regnum (valtry)) >= 0)))
6114 if (other >= 0
6115 ? valueno == other
6116 : ((unsigned) valueno < FIRST_PSEUDO_REGISTER
6117 && TEST_HARD_REG_BIT (reg_class_contents[(int) class],
6118 valueno)))
6120 value = valtry;
6121 where = p;
6122 break;
6127 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6128 (or copying VALUE into GOAL, if GOAL is also a register).
6129 Now verify that VALUE is really valid. */
6131 /* VALUENO is the register number of VALUE; a hard register. */
6133 /* Don't try to re-use something that is killed in this insn. We want
6134 to be able to trust REG_UNUSED notes. */
6135 if (find_reg_note (where, REG_UNUSED, value))
6136 return 0;
6138 /* If we propose to get the value from the stack pointer or if GOAL is
6139 a MEM based on the stack pointer, we need a stable SP. */
6140 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6141 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6142 goal)))
6143 need_stable_sp = 1;
6145 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6146 if (GET_MODE (value) != mode)
6147 return 0;
6149 /* Reject VALUE if it was loaded from GOAL
6150 and is also a register that appears in the address of GOAL. */
6152 if (goal_mem && value == SET_DEST (single_set (where))
6153 && refers_to_regno_for_reload_p (valueno,
6154 (valueno
6155 + HARD_REGNO_NREGS (valueno, mode)),
6156 goal, NULL_PTR))
6157 return 0;
6159 /* Reject registers that overlap GOAL. */
6161 if (!goal_mem && !goal_const
6162 && regno + HARD_REGNO_NREGS (regno, mode) > valueno
6163 && regno < valueno + HARD_REGNO_NREGS (valueno, mode))
6164 return 0;
6166 /* Reject VALUE if it is one of the regs reserved for reloads.
6167 Reload1 knows how to reuse them anyway, and it would get
6168 confused if we allocated one without its knowledge.
6169 (Now that insns introduced by reload are ignored above,
6170 this case shouldn't happen, but I'm not positive.) */
6172 if (reload_reg_p != 0 && reload_reg_p != (short *) (HOST_WIDE_INT) 1
6173 && reload_reg_p[valueno] >= 0)
6174 return 0;
6176 /* On some machines, certain regs must always be rejected
6177 because they don't behave the way ordinary registers do. */
6179 #ifdef OVERLAPPING_REGNO_P
6180 if (OVERLAPPING_REGNO_P (valueno))
6181 return 0;
6182 #endif
6184 nregs = HARD_REGNO_NREGS (regno, mode);
6185 valuenregs = HARD_REGNO_NREGS (valueno, mode);
6187 /* Reject VALUE if it is a register being used for an input reload
6188 even if it is not one of those reserved. */
6190 if (reload_reg_p != 0)
6192 int i;
6193 for (i = 0; i < n_reloads; i++)
6194 if (rld[i].reg_rtx != 0 && rld[i].in)
6196 int regno1 = REGNO (rld[i].reg_rtx);
6197 int nregs1 = HARD_REGNO_NREGS (regno1,
6198 GET_MODE (rld[i].reg_rtx));
6199 if (regno1 < valueno + valuenregs
6200 && regno1 + nregs1 > valueno)
6201 return 0;
6205 if (goal_mem)
6206 /* We must treat frame pointer as varying here,
6207 since it can vary--in a nonlocal goto as generated by expand_goto. */
6208 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6210 /* Now verify that the values of GOAL and VALUE remain unaltered
6211 until INSN is reached. */
6213 p = insn;
6214 while (1)
6216 p = PREV_INSN (p);
6217 if (p == where)
6218 return value;
6220 /* Don't trust the conversion past a function call
6221 if either of the two is in a call-clobbered register, or memory. */
6222 if (GET_CODE (p) == CALL_INSN
6223 && ((regno >= 0 && regno < FIRST_PSEUDO_REGISTER
6224 && call_used_regs[regno])
6226 (valueno >= 0 && valueno < FIRST_PSEUDO_REGISTER
6227 && call_used_regs[valueno])
6229 goal_mem
6230 || need_stable_sp))
6231 return 0;
6233 #ifdef NON_SAVING_SETJMP
6234 if (NON_SAVING_SETJMP && GET_CODE (p) == NOTE
6235 && NOTE_LINE_NUMBER (p) == NOTE_INSN_SETJMP)
6236 return 0;
6237 #endif
6239 #ifdef INSN_CLOBBERS_REGNO_P
6240 if ((valueno >= 0 && valueno < FIRST_PSEUDO_REGISTER
6241 && INSN_CLOBBERS_REGNO_P (p, valueno))
6242 || (regno >= 0 && regno < FIRST_PSEUDO_REGISTER
6243 && INSN_CLOBBERS_REGNO_P (p, regno)))
6244 return 0;
6245 #endif
6247 if (GET_RTX_CLASS (GET_CODE (p)) == 'i')
6249 pat = PATTERN (p);
6251 /* Watch out for unspec_volatile, and volatile asms. */
6252 if (volatile_insn_p (pat))
6253 return 0;
6255 /* If this insn P stores in either GOAL or VALUE, return 0.
6256 If GOAL is a memory ref and this insn writes memory, return 0.
6257 If GOAL is a memory ref and its address is not constant,
6258 and this insn P changes a register used in GOAL, return 0. */
6260 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6262 register rtx dest = SET_DEST (pat);
6263 while (GET_CODE (dest) == SUBREG
6264 || GET_CODE (dest) == ZERO_EXTRACT
6265 || GET_CODE (dest) == SIGN_EXTRACT
6266 || GET_CODE (dest) == STRICT_LOW_PART)
6267 dest = XEXP (dest, 0);
6268 if (GET_CODE (dest) == REG)
6270 register int xregno = REGNO (dest);
6271 int xnregs;
6272 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6273 xnregs = HARD_REGNO_NREGS (xregno, GET_MODE (dest));
6274 else
6275 xnregs = 1;
6276 if (xregno < regno + nregs && xregno + xnregs > regno)
6277 return 0;
6278 if (xregno < valueno + valuenregs
6279 && xregno + xnregs > valueno)
6280 return 0;
6281 if (goal_mem_addr_varies
6282 && reg_overlap_mentioned_for_reload_p (dest, goal))
6283 return 0;
6284 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6285 return 0;
6287 else if (goal_mem && GET_CODE (dest) == MEM
6288 && ! push_operand (dest, GET_MODE (dest)))
6289 return 0;
6290 else if (GET_CODE (dest) == MEM && regno >= FIRST_PSEUDO_REGISTER
6291 && reg_equiv_memory_loc[regno] != 0)
6292 return 0;
6293 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6294 return 0;
6296 else if (GET_CODE (pat) == PARALLEL)
6298 register int i;
6299 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6301 register rtx v1 = XVECEXP (pat, 0, i);
6302 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6304 register rtx dest = SET_DEST (v1);
6305 while (GET_CODE (dest) == SUBREG
6306 || GET_CODE (dest) == ZERO_EXTRACT
6307 || GET_CODE (dest) == SIGN_EXTRACT
6308 || GET_CODE (dest) == STRICT_LOW_PART)
6309 dest = XEXP (dest, 0);
6310 if (GET_CODE (dest) == REG)
6312 register int xregno = REGNO (dest);
6313 int xnregs;
6314 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6315 xnregs = HARD_REGNO_NREGS (xregno, GET_MODE (dest));
6316 else
6317 xnregs = 1;
6318 if (xregno < regno + nregs
6319 && xregno + xnregs > regno)
6320 return 0;
6321 if (xregno < valueno + valuenregs
6322 && xregno + xnregs > valueno)
6323 return 0;
6324 if (goal_mem_addr_varies
6325 && reg_overlap_mentioned_for_reload_p (dest,
6326 goal))
6327 return 0;
6328 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6329 return 0;
6331 else if (goal_mem && GET_CODE (dest) == MEM
6332 && ! push_operand (dest, GET_MODE (dest)))
6333 return 0;
6334 else if (GET_CODE (dest) == MEM && regno >= FIRST_PSEUDO_REGISTER
6335 && reg_equiv_memory_loc[regno] != 0)
6336 return 0;
6337 else if (need_stable_sp
6338 && push_operand (dest, GET_MODE (dest)))
6339 return 0;
6344 if (GET_CODE (p) == CALL_INSN && CALL_INSN_FUNCTION_USAGE (p))
6346 rtx link;
6348 for (link = CALL_INSN_FUNCTION_USAGE (p); XEXP (link, 1) != 0;
6349 link = XEXP (link, 1))
6351 pat = XEXP (link, 0);
6352 if (GET_CODE (pat) == CLOBBER)
6354 register rtx dest = SET_DEST (pat);
6355 while (GET_CODE (dest) == SUBREG
6356 || GET_CODE (dest) == ZERO_EXTRACT
6357 || GET_CODE (dest) == SIGN_EXTRACT
6358 || GET_CODE (dest) == STRICT_LOW_PART)
6359 dest = XEXP (dest, 0);
6360 if (GET_CODE (dest) == REG)
6362 register int xregno = REGNO (dest);
6363 int xnregs;
6364 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6365 xnregs = HARD_REGNO_NREGS (xregno, GET_MODE (dest));
6366 else
6367 xnregs = 1;
6368 if (xregno < regno + nregs
6369 && xregno + xnregs > regno)
6370 return 0;
6371 if (xregno < valueno + valuenregs
6372 && xregno + xnregs > valueno)
6373 return 0;
6374 if (goal_mem_addr_varies
6375 && reg_overlap_mentioned_for_reload_p (dest,
6376 goal))
6377 return 0;
6379 else if (goal_mem && GET_CODE (dest) == MEM
6380 && ! push_operand (dest, GET_MODE (dest)))
6381 return 0;
6382 else if (need_stable_sp
6383 && push_operand (dest, GET_MODE (dest)))
6384 return 0;
6389 #ifdef AUTO_INC_DEC
6390 /* If this insn auto-increments or auto-decrements
6391 either regno or valueno, return 0 now.
6392 If GOAL is a memory ref and its address is not constant,
6393 and this insn P increments a register used in GOAL, return 0. */
6395 register rtx link;
6397 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
6398 if (REG_NOTE_KIND (link) == REG_INC
6399 && GET_CODE (XEXP (link, 0)) == REG)
6401 register int incno = REGNO (XEXP (link, 0));
6402 if (incno < regno + nregs && incno >= regno)
6403 return 0;
6404 if (incno < valueno + valuenregs && incno >= valueno)
6405 return 0;
6406 if (goal_mem_addr_varies
6407 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
6408 goal))
6409 return 0;
6412 #endif
6417 /* Find a place where INCED appears in an increment or decrement operator
6418 within X, and return the amount INCED is incremented or decremented by.
6419 The value is always positive. */
6421 static int
6422 find_inc_amount (x, inced)
6423 rtx x, inced;
6425 register enum rtx_code code = GET_CODE (x);
6426 register const char *fmt;
6427 register int i;
6429 if (code == MEM)
6431 register rtx addr = XEXP (x, 0);
6432 if ((GET_CODE (addr) == PRE_DEC
6433 || GET_CODE (addr) == POST_DEC
6434 || GET_CODE (addr) == PRE_INC
6435 || GET_CODE (addr) == POST_INC)
6436 && XEXP (addr, 0) == inced)
6437 return GET_MODE_SIZE (GET_MODE (x));
6440 fmt = GET_RTX_FORMAT (code);
6441 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6443 if (fmt[i] == 'e')
6445 register int tem = find_inc_amount (XEXP (x, i), inced);
6446 if (tem != 0)
6447 return tem;
6449 if (fmt[i] == 'E')
6451 register int j;
6452 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6454 register int tem = find_inc_amount (XVECEXP (x, i, j), inced);
6455 if (tem != 0)
6456 return tem;
6461 return 0;
6464 /* Return 1 if register REGNO is the subject of a clobber in insn INSN. */
6467 regno_clobbered_p (regno, insn)
6468 int regno;
6469 rtx insn;
6471 if (GET_CODE (PATTERN (insn)) == CLOBBER
6472 && GET_CODE (XEXP (PATTERN (insn), 0)) == REG)
6473 return REGNO (XEXP (PATTERN (insn), 0)) == regno;
6475 if (GET_CODE (PATTERN (insn)) == PARALLEL)
6477 int i = XVECLEN (PATTERN (insn), 0) - 1;
6479 for (; i >= 0; i--)
6481 rtx elt = XVECEXP (PATTERN (insn), 0, i);
6482 if (GET_CODE (elt) == CLOBBER && GET_CODE (XEXP (elt, 0)) == REG
6483 && REGNO (XEXP (elt, 0)) == regno)
6484 return 1;
6488 return 0;
6491 static const char *reload_when_needed_name[] =
6493 "RELOAD_FOR_INPUT",
6494 "RELOAD_FOR_OUTPUT",
6495 "RELOAD_FOR_INSN",
6496 "RELOAD_FOR_INPUT_ADDRESS",
6497 "RELOAD_FOR_INPADDR_ADDRESS",
6498 "RELOAD_FOR_OUTPUT_ADDRESS",
6499 "RELOAD_FOR_OUTADDR_ADDRESS",
6500 "RELOAD_FOR_OPERAND_ADDRESS",
6501 "RELOAD_FOR_OPADDR_ADDR",
6502 "RELOAD_OTHER",
6503 "RELOAD_FOR_OTHER_ADDRESS"
6506 static const char * const reg_class_names[] = REG_CLASS_NAMES;
6508 /* These functions are used to print the variables set by 'find_reloads' */
6510 void
6511 debug_reload_to_stream (f)
6512 FILE *f;
6514 int r;
6515 const char *prefix;
6517 if (! f)
6518 f = stderr;
6519 for (r = 0; r < n_reloads; r++)
6521 fprintf (f, "Reload %d: ", r);
6523 if (rld[r].in != 0)
6525 fprintf (f, "reload_in (%s) = ",
6526 GET_MODE_NAME (rld[r].inmode));
6527 print_inline_rtx (f, rld[r].in, 24);
6528 fprintf (f, "\n\t");
6531 if (rld[r].out != 0)
6533 fprintf (f, "reload_out (%s) = ",
6534 GET_MODE_NAME (rld[r].outmode));
6535 print_inline_rtx (f, rld[r].out, 24);
6536 fprintf (f, "\n\t");
6539 fprintf (f, "%s, ", reg_class_names[(int) rld[r].class]);
6541 fprintf (f, "%s (opnum = %d)",
6542 reload_when_needed_name[(int) rld[r].when_needed],
6543 rld[r].opnum);
6545 if (rld[r].optional)
6546 fprintf (f, ", optional");
6548 if (rld[r].nongroup)
6549 fprintf (stderr, ", nongroup");
6551 if (rld[r].inc != 0)
6552 fprintf (f, ", inc by %d", rld[r].inc);
6554 if (rld[r].nocombine)
6555 fprintf (f, ", can't combine");
6557 if (rld[r].secondary_p)
6558 fprintf (f, ", secondary_reload_p");
6560 if (rld[r].in_reg != 0)
6562 fprintf (f, "\n\treload_in_reg: ");
6563 print_inline_rtx (f, rld[r].in_reg, 24);
6566 if (rld[r].out_reg != 0)
6568 fprintf (f, "\n\treload_out_reg: ");
6569 print_inline_rtx (f, rld[r].out_reg, 24);
6572 if (rld[r].reg_rtx != 0)
6574 fprintf (f, "\n\treload_reg_rtx: ");
6575 print_inline_rtx (f, rld[r].reg_rtx, 24);
6578 prefix = "\n\t";
6579 if (rld[r].secondary_in_reload != -1)
6581 fprintf (f, "%ssecondary_in_reload = %d",
6582 prefix, rld[r].secondary_in_reload);
6583 prefix = ", ";
6586 if (rld[r].secondary_out_reload != -1)
6587 fprintf (f, "%ssecondary_out_reload = %d\n",
6588 prefix, rld[r].secondary_out_reload);
6590 prefix = "\n\t";
6591 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
6593 fprintf (stderr, "%ssecondary_in_icode = %s", prefix,
6594 insn_data[rld[r].secondary_in_icode].name);
6595 prefix = ", ";
6598 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
6599 fprintf (stderr, "%ssecondary_out_icode = %s", prefix,
6600 insn_data[rld[r].secondary_out_icode].name);
6602 fprintf (f, "\n");
6606 void
6607 debug_reload ()
6609 debug_reload_to_stream (stderr);