* configure.ac (HAVE_GAS_CFI_DIRECTIVE): Always test for assembler
[official-gcc.git] / gcc / reload.c
blob5a79c44e8745e44a4ad701796c57a4e1736edc40
1 /* Search an insn for pseudo regs that must be in hard regs and are not.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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'.
30 init_reload actually has to be called earlier anyway.
32 To scan an insn, call `find_reloads'. This does two things:
33 1. sets up tables describing which values must be reloaded
34 for this insn, and what kind of hard regs they must be reloaded into;
35 2. optionally record the locations where those values appear in
36 the data, so they can be replaced properly later.
37 This is done only if the second arg to `find_reloads' is nonzero.
39 The third arg to `find_reloads' specifies the number of levels
40 of indirect addressing supported by the machine. If it is zero,
41 indirect addressing is not valid. If it is one, (MEM (REG n))
42 is valid even if (REG n) did not get a hard register; if it is two,
43 (MEM (MEM (REG n))) is also valid even if (REG n) did not get a
44 hard register, and similarly for higher values.
46 Then you must choose the hard regs to reload those pseudo regs into,
47 and generate appropriate load insns before this insn and perhaps
48 also store insns after this insn. Set up the array `reload_reg_rtx'
49 to contain the REG rtx's for the registers you used. In some
50 cases `find_reloads' will return a nonzero value in `reload_reg_rtx'
51 for certain reloads. Then that tells you which register to use,
52 so you do not need to allocate one. But you still do need to add extra
53 instructions to copy the value into and out of that register.
55 Finally you must call `subst_reloads' to substitute the reload reg rtx's
56 into the locations already recorded.
58 NOTE SIDE EFFECTS:
60 find_reloads can alter the operands of the instruction it is called on.
62 1. Two operands of any sort may be interchanged, if they are in a
63 commutative instruction.
64 This happens only if find_reloads thinks the instruction will compile
65 better that way.
67 2. Pseudo-registers that are equivalent to constants are replaced
68 with those constants if they are not in hard registers.
70 1 happens every time find_reloads is called.
71 2 happens only when REPLACE is 1, which is only when
72 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 /* We do not enable this with ENABLE_CHECKING, since it is awfully slow. */
91 #undef DEBUG_RELOAD
93 #include "config.h"
94 #include "system.h"
95 #include "coretypes.h"
96 #include "tm.h"
97 #include "rtl.h"
98 #include "tm_p.h"
99 #include "insn-config.h"
100 #include "expr.h"
101 #include "optabs.h"
102 #include "recog.h"
103 #include "reload.h"
104 #include "regs.h"
105 #include "addresses.h"
106 #include "hard-reg-set.h"
107 #include "flags.h"
108 #include "real.h"
109 #include "output.h"
110 #include "function.h"
111 #include "toplev.h"
112 #include "params.h"
113 #include "target.h"
114 #include "df.h"
116 /* True if X is a constant that can be forced into the constant pool. */
117 #define CONST_POOL_OK_P(X) \
118 (CONSTANT_P (X) \
119 && GET_CODE (X) != HIGH \
120 && !targetm.cannot_force_const_mem (X))
122 /* True if C is a non-empty register class that has too few registers
123 to be safely used as a reload target class. */
124 #define SMALL_REGISTER_CLASS_P(C) \
125 (reg_class_size [(C)] == 1 \
126 || (reg_class_size [(C)] >= 1 && CLASS_LIKELY_SPILLED_P (C)))
129 /* All reloads of the current insn are recorded here. See reload.h for
130 comments. */
131 int n_reloads;
132 struct reload rld[MAX_RELOADS];
134 /* All the "earlyclobber" operands of the current insn
135 are recorded here. */
136 int n_earlyclobbers;
137 rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
139 int reload_n_operands;
141 /* Replacing reloads.
143 If `replace_reloads' is nonzero, then as each reload is recorded
144 an entry is made for it in the table `replacements'.
145 Then later `subst_reloads' can look through that table and
146 perform all the replacements needed. */
148 /* Nonzero means record the places to replace. */
149 static int replace_reloads;
151 /* Each replacement is recorded with a structure like this. */
152 struct replacement
154 rtx *where; /* Location to store in */
155 rtx *subreg_loc; /* Location of SUBREG if WHERE is inside
156 a SUBREG; 0 otherwise. */
157 int what; /* which reload this is for */
158 enum machine_mode mode; /* mode it must have */
161 static struct replacement replacements[MAX_RECOG_OPERANDS * ((MAX_REGS_PER_ADDRESS * 2) + 1)];
163 /* Number of replacements currently recorded. */
164 static int n_replacements;
166 /* Used to track what is modified by an operand. */
167 struct decomposition
169 int reg_flag; /* Nonzero if referencing a register. */
170 int safe; /* Nonzero if this can't conflict with anything. */
171 rtx base; /* Base address for MEM. */
172 HOST_WIDE_INT start; /* Starting offset or register number. */
173 HOST_WIDE_INT end; /* Ending offset or register number. */
176 #ifdef SECONDARY_MEMORY_NEEDED
178 /* Save MEMs needed to copy from one class of registers to another. One MEM
179 is used per mode, but normally only one or two modes are ever used.
181 We keep two versions, before and after register elimination. The one
182 after register elimination is record separately for each operand. This
183 is done in case the address is not valid to be sure that we separately
184 reload each. */
186 static rtx secondary_memlocs[NUM_MACHINE_MODES];
187 static rtx secondary_memlocs_elim[NUM_MACHINE_MODES][MAX_RECOG_OPERANDS];
188 static int secondary_memlocs_elim_used = 0;
189 #endif
191 /* The instruction we are doing reloads for;
192 so we can test whether a register dies in it. */
193 static rtx this_insn;
195 /* Nonzero if this instruction is a user-specified asm with operands. */
196 static int this_insn_is_asm;
198 /* If hard_regs_live_known is nonzero,
199 we can tell which hard regs are currently live,
200 at least enough to succeed in choosing dummy reloads. */
201 static int hard_regs_live_known;
203 /* Indexed by hard reg number,
204 element is nonnegative if hard reg has been spilled.
205 This vector is passed to `find_reloads' as an argument
206 and is not changed here. */
207 static short *static_reload_reg_p;
209 /* Set to 1 in subst_reg_equivs if it changes anything. */
210 static int subst_reg_equivs_changed;
212 /* On return from push_reload, holds the reload-number for the OUT
213 operand, which can be different for that from the input operand. */
214 static int output_reloadnum;
216 /* Compare two RTX's. */
217 #define MATCHES(x, y) \
218 (x == y || (x != 0 && (REG_P (x) \
219 ? REG_P (y) && REGNO (x) == REGNO (y) \
220 : rtx_equal_p (x, y) && ! side_effects_p (x))))
222 /* Indicates if two reloads purposes are for similar enough things that we
223 can merge their reloads. */
224 #define MERGABLE_RELOADS(when1, when2, op1, op2) \
225 ((when1) == RELOAD_OTHER || (when2) == RELOAD_OTHER \
226 || ((when1) == (when2) && (op1) == (op2)) \
227 || ((when1) == RELOAD_FOR_INPUT && (when2) == RELOAD_FOR_INPUT) \
228 || ((when1) == RELOAD_FOR_OPERAND_ADDRESS \
229 && (when2) == RELOAD_FOR_OPERAND_ADDRESS) \
230 || ((when1) == RELOAD_FOR_OTHER_ADDRESS \
231 && (when2) == RELOAD_FOR_OTHER_ADDRESS))
233 /* Nonzero if these two reload purposes produce RELOAD_OTHER when merged. */
234 #define MERGE_TO_OTHER(when1, when2, op1, op2) \
235 ((when1) != (when2) \
236 || ! ((op1) == (op2) \
237 || (when1) == RELOAD_FOR_INPUT \
238 || (when1) == RELOAD_FOR_OPERAND_ADDRESS \
239 || (when1) == RELOAD_FOR_OTHER_ADDRESS))
241 /* If we are going to reload an address, compute the reload type to
242 use. */
243 #define ADDR_TYPE(type) \
244 ((type) == RELOAD_FOR_INPUT_ADDRESS \
245 ? RELOAD_FOR_INPADDR_ADDRESS \
246 : ((type) == RELOAD_FOR_OUTPUT_ADDRESS \
247 ? RELOAD_FOR_OUTADDR_ADDRESS \
248 : (type)))
250 static int push_secondary_reload (int, rtx, int, int, enum reg_class,
251 enum machine_mode, enum reload_type,
252 enum insn_code *, secondary_reload_info *);
253 static enum reg_class find_valid_class (enum machine_mode, enum machine_mode,
254 int, unsigned int);
255 static int reload_inner_reg_of_subreg (rtx, enum machine_mode, int);
256 static void push_replacement (rtx *, int, enum machine_mode);
257 static void dup_replacements (rtx *, rtx *);
258 static void combine_reloads (void);
259 static int find_reusable_reload (rtx *, rtx, enum reg_class,
260 enum reload_type, int, int);
261 static rtx find_dummy_reload (rtx, rtx, rtx *, rtx *, enum machine_mode,
262 enum machine_mode, enum reg_class, int, int);
263 static int hard_reg_set_here_p (unsigned int, unsigned int, rtx);
264 static struct decomposition decompose (rtx);
265 static int immune_p (rtx, rtx, struct decomposition);
266 static bool alternative_allows_const_pool_ref (rtx, const char *, int);
267 static rtx find_reloads_toplev (rtx, int, enum reload_type, int, int, rtx,
268 int *);
269 static rtx make_memloc (rtx, int);
270 static int maybe_memory_address_p (enum machine_mode, rtx, rtx *);
271 static int find_reloads_address (enum machine_mode, rtx *, rtx, rtx *,
272 int, enum reload_type, int, rtx);
273 static rtx subst_reg_equivs (rtx, rtx);
274 static rtx subst_indexed_address (rtx);
275 static void update_auto_inc_notes (rtx, int, int);
276 static int find_reloads_address_1 (enum machine_mode, rtx, int,
277 enum rtx_code, enum rtx_code, rtx *,
278 int, enum reload_type,int, rtx);
279 static void find_reloads_address_part (rtx, rtx *, enum reg_class,
280 enum machine_mode, int,
281 enum reload_type, int);
282 static rtx find_reloads_subreg_address (rtx, int, int, enum reload_type,
283 int, rtx);
284 static void copy_replacements_1 (rtx *, rtx *, int);
285 static int find_inc_amount (rtx, rtx);
286 static int refers_to_mem_for_reload_p (rtx);
287 static int refers_to_regno_for_reload_p (unsigned int, unsigned int,
288 rtx, rtx *);
290 /* Add NEW to reg_equiv_alt_mem_list[REGNO] if it's not present in the
291 list yet. */
293 static void
294 push_reg_equiv_alt_mem (int regno, rtx mem)
296 rtx it;
298 for (it = reg_equiv_alt_mem_list [regno]; it; it = XEXP (it, 1))
299 if (rtx_equal_p (XEXP (it, 0), mem))
300 return;
302 reg_equiv_alt_mem_list [regno]
303 = alloc_EXPR_LIST (REG_EQUIV, mem,
304 reg_equiv_alt_mem_list [regno]);
307 /* Determine if any secondary reloads are needed for loading (if IN_P is
308 nonzero) or storing (if IN_P is zero) X to or from a reload register of
309 register class RELOAD_CLASS in mode RELOAD_MODE. If secondary reloads
310 are needed, push them.
312 Return the reload number of the secondary reload we made, or -1 if
313 we didn't need one. *PICODE is set to the insn_code to use if we do
314 need a secondary reload. */
316 static int
317 push_secondary_reload (int in_p, rtx x, int opnum, int optional,
318 enum reg_class reload_class,
319 enum machine_mode reload_mode, enum reload_type type,
320 enum insn_code *picode, secondary_reload_info *prev_sri)
322 enum reg_class rclass = NO_REGS;
323 enum reg_class scratch_class;
324 enum machine_mode mode = reload_mode;
325 enum insn_code icode = CODE_FOR_nothing;
326 enum insn_code t_icode = CODE_FOR_nothing;
327 enum reload_type secondary_type;
328 int s_reload, t_reload = -1;
329 const char *scratch_constraint;
330 char letter;
331 secondary_reload_info sri;
333 if (type == RELOAD_FOR_INPUT_ADDRESS
334 || type == RELOAD_FOR_OUTPUT_ADDRESS
335 || type == RELOAD_FOR_INPADDR_ADDRESS
336 || type == RELOAD_FOR_OUTADDR_ADDRESS)
337 secondary_type = type;
338 else
339 secondary_type = in_p ? RELOAD_FOR_INPUT_ADDRESS : RELOAD_FOR_OUTPUT_ADDRESS;
341 *picode = CODE_FOR_nothing;
343 /* If X is a paradoxical SUBREG, use the inner value to determine both the
344 mode and object being reloaded. */
345 if (GET_CODE (x) == SUBREG
346 && (GET_MODE_SIZE (GET_MODE (x))
347 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))))
349 x = SUBREG_REG (x);
350 reload_mode = GET_MODE (x);
353 /* If X is a pseudo-register that has an equivalent MEM (actually, if it
354 is still a pseudo-register by now, it *must* have an equivalent MEM
355 but we don't want to assume that), use that equivalent when seeing if
356 a secondary reload is needed since whether or not a reload is needed
357 might be sensitive to the form of the MEM. */
359 if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER
360 && reg_equiv_mem[REGNO (x)] != 0)
361 x = reg_equiv_mem[REGNO (x)];
363 sri.icode = CODE_FOR_nothing;
364 sri.prev_sri = prev_sri;
365 rclass = targetm.secondary_reload (in_p, x, reload_class, reload_mode, &sri);
366 icode = sri.icode;
368 /* If we don't need any secondary registers, done. */
369 if (rclass == NO_REGS && icode == CODE_FOR_nothing)
370 return -1;
372 if (rclass != NO_REGS)
373 t_reload = push_secondary_reload (in_p, x, opnum, optional, rclass,
374 reload_mode, type, &t_icode, &sri);
376 /* If we will be using an insn, the secondary reload is for a
377 scratch register. */
379 if (icode != CODE_FOR_nothing)
381 /* If IN_P is nonzero, the reload register will be the output in
382 operand 0. If IN_P is zero, the reload register will be the input
383 in operand 1. Outputs should have an initial "=", which we must
384 skip. */
386 /* ??? It would be useful to be able to handle only two, or more than
387 three, operands, but for now we can only handle the case of having
388 exactly three: output, input and one temp/scratch. */
389 gcc_assert (insn_data[(int) icode].n_operands == 3);
391 /* ??? We currently have no way to represent a reload that needs
392 an icode to reload from an intermediate tertiary reload register.
393 We should probably have a new field in struct reload to tag a
394 chain of scratch operand reloads onto. */
395 gcc_assert (rclass == NO_REGS);
397 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
398 gcc_assert (*scratch_constraint == '=');
399 scratch_constraint++;
400 if (*scratch_constraint == '&')
401 scratch_constraint++;
402 letter = *scratch_constraint;
403 scratch_class = (letter == 'r' ? GENERAL_REGS
404 : REG_CLASS_FROM_CONSTRAINT ((unsigned char) letter,
405 scratch_constraint));
407 rclass = scratch_class;
408 mode = insn_data[(int) icode].operand[2].mode;
411 /* This case isn't valid, so fail. Reload is allowed to use the same
412 register for RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT reloads, but
413 in the case of a secondary register, we actually need two different
414 registers for correct code. We fail here to prevent the possibility of
415 silently generating incorrect code later.
417 The convention is that secondary input reloads are valid only if the
418 secondary_class is different from class. If you have such a case, you
419 can not use secondary reloads, you must work around the problem some
420 other way.
422 Allow this when a reload_in/out pattern is being used. I.e. assume
423 that the generated code handles this case. */
425 gcc_assert (!in_p || rclass != reload_class || icode != CODE_FOR_nothing
426 || t_icode != CODE_FOR_nothing);
428 /* See if we can reuse an existing secondary reload. */
429 for (s_reload = 0; s_reload < n_reloads; s_reload++)
430 if (rld[s_reload].secondary_p
431 && (reg_class_subset_p (rclass, rld[s_reload].rclass)
432 || reg_class_subset_p (rld[s_reload].rclass, rclass))
433 && ((in_p && rld[s_reload].inmode == mode)
434 || (! in_p && rld[s_reload].outmode == mode))
435 && ((in_p && rld[s_reload].secondary_in_reload == t_reload)
436 || (! in_p && rld[s_reload].secondary_out_reload == t_reload))
437 && ((in_p && rld[s_reload].secondary_in_icode == t_icode)
438 || (! in_p && rld[s_reload].secondary_out_icode == t_icode))
439 && (SMALL_REGISTER_CLASS_P (rclass) || SMALL_REGISTER_CLASSES)
440 && MERGABLE_RELOADS (secondary_type, rld[s_reload].when_needed,
441 opnum, rld[s_reload].opnum))
443 if (in_p)
444 rld[s_reload].inmode = mode;
445 if (! in_p)
446 rld[s_reload].outmode = mode;
448 if (reg_class_subset_p (rclass, rld[s_reload].rclass))
449 rld[s_reload].rclass = rclass;
451 rld[s_reload].opnum = MIN (rld[s_reload].opnum, opnum);
452 rld[s_reload].optional &= optional;
453 rld[s_reload].secondary_p = 1;
454 if (MERGE_TO_OTHER (secondary_type, rld[s_reload].when_needed,
455 opnum, rld[s_reload].opnum))
456 rld[s_reload].when_needed = RELOAD_OTHER;
458 break;
461 if (s_reload == n_reloads)
463 #ifdef SECONDARY_MEMORY_NEEDED
464 /* If we need a memory location to copy between the two reload regs,
465 set it up now. Note that we do the input case before making
466 the reload and the output case after. This is due to the
467 way reloads are output. */
469 if (in_p && icode == CODE_FOR_nothing
470 && SECONDARY_MEMORY_NEEDED (rclass, reload_class, mode))
472 get_secondary_mem (x, reload_mode, opnum, type);
474 /* We may have just added new reloads. Make sure we add
475 the new reload at the end. */
476 s_reload = n_reloads;
478 #endif
480 /* We need to make a new secondary reload for this register class. */
481 rld[s_reload].in = rld[s_reload].out = 0;
482 rld[s_reload].rclass = rclass;
484 rld[s_reload].inmode = in_p ? mode : VOIDmode;
485 rld[s_reload].outmode = ! in_p ? mode : VOIDmode;
486 rld[s_reload].reg_rtx = 0;
487 rld[s_reload].optional = optional;
488 rld[s_reload].inc = 0;
489 /* Maybe we could combine these, but it seems too tricky. */
490 rld[s_reload].nocombine = 1;
491 rld[s_reload].in_reg = 0;
492 rld[s_reload].out_reg = 0;
493 rld[s_reload].opnum = opnum;
494 rld[s_reload].when_needed = secondary_type;
495 rld[s_reload].secondary_in_reload = in_p ? t_reload : -1;
496 rld[s_reload].secondary_out_reload = ! in_p ? t_reload : -1;
497 rld[s_reload].secondary_in_icode = in_p ? t_icode : CODE_FOR_nothing;
498 rld[s_reload].secondary_out_icode
499 = ! in_p ? t_icode : CODE_FOR_nothing;
500 rld[s_reload].secondary_p = 1;
502 n_reloads++;
504 #ifdef SECONDARY_MEMORY_NEEDED
505 if (! in_p && icode == CODE_FOR_nothing
506 && SECONDARY_MEMORY_NEEDED (reload_class, rclass, mode))
507 get_secondary_mem (x, mode, opnum, type);
508 #endif
511 *picode = icode;
512 return s_reload;
515 /* If a secondary reload is needed, return its class. If both an intermediate
516 register and a scratch register is needed, we return the class of the
517 intermediate register. */
518 enum reg_class
519 secondary_reload_class (bool in_p, enum reg_class rclass,
520 enum machine_mode mode, rtx x)
522 enum insn_code icode;
523 secondary_reload_info sri;
525 sri.icode = CODE_FOR_nothing;
526 sri.prev_sri = NULL;
527 rclass = targetm.secondary_reload (in_p, x, rclass, mode, &sri);
528 icode = sri.icode;
530 /* If there are no secondary reloads at all, we return NO_REGS.
531 If an intermediate register is needed, we return its class. */
532 if (icode == CODE_FOR_nothing || rclass != NO_REGS)
533 return rclass;
535 /* No intermediate register is needed, but we have a special reload
536 pattern, which we assume for now needs a scratch register. */
537 return scratch_reload_class (icode);
540 /* ICODE is the insn_code of a reload pattern. Check that it has exactly
541 three operands, verify that operand 2 is an output operand, and return
542 its register class.
543 ??? We'd like to be able to handle any pattern with at least 2 operands,
544 for zero or more scratch registers, but that needs more infrastructure. */
545 enum reg_class
546 scratch_reload_class (enum insn_code icode)
548 const char *scratch_constraint;
549 char scratch_letter;
550 enum reg_class rclass;
552 gcc_assert (insn_data[(int) icode].n_operands == 3);
553 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
554 gcc_assert (*scratch_constraint == '=');
555 scratch_constraint++;
556 if (*scratch_constraint == '&')
557 scratch_constraint++;
558 scratch_letter = *scratch_constraint;
559 if (scratch_letter == 'r')
560 return GENERAL_REGS;
561 rclass = REG_CLASS_FROM_CONSTRAINT ((unsigned char) scratch_letter,
562 scratch_constraint);
563 gcc_assert (rclass != NO_REGS);
564 return rclass;
567 #ifdef SECONDARY_MEMORY_NEEDED
569 /* Return a memory location that will be used to copy X in mode MODE.
570 If we haven't already made a location for this mode in this insn,
571 call find_reloads_address on the location being returned. */
574 get_secondary_mem (rtx x ATTRIBUTE_UNUSED, enum machine_mode mode,
575 int opnum, enum reload_type type)
577 rtx loc;
578 int mem_valid;
580 /* By default, if MODE is narrower than a word, widen it to a word.
581 This is required because most machines that require these memory
582 locations do not support short load and stores from all registers
583 (e.g., FP registers). */
585 #ifdef SECONDARY_MEMORY_NEEDED_MODE
586 mode = SECONDARY_MEMORY_NEEDED_MODE (mode);
587 #else
588 if (GET_MODE_BITSIZE (mode) < BITS_PER_WORD && INTEGRAL_MODE_P (mode))
589 mode = mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (mode), 0);
590 #endif
592 /* If we already have made a MEM for this operand in MODE, return it. */
593 if (secondary_memlocs_elim[(int) mode][opnum] != 0)
594 return secondary_memlocs_elim[(int) mode][opnum];
596 /* If this is the first time we've tried to get a MEM for this mode,
597 allocate a new one. `something_changed' in reload will get set
598 by noticing that the frame size has changed. */
600 if (secondary_memlocs[(int) mode] == 0)
602 #ifdef SECONDARY_MEMORY_NEEDED_RTX
603 secondary_memlocs[(int) mode] = SECONDARY_MEMORY_NEEDED_RTX (mode);
604 #else
605 secondary_memlocs[(int) mode]
606 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
607 #endif
610 /* Get a version of the address doing any eliminations needed. If that
611 didn't give us a new MEM, make a new one if it isn't valid. */
613 loc = eliminate_regs (secondary_memlocs[(int) mode], VOIDmode, NULL_RTX);
614 mem_valid = strict_memory_address_p (mode, XEXP (loc, 0));
616 if (! mem_valid && loc == secondary_memlocs[(int) mode])
617 loc = copy_rtx (loc);
619 /* The only time the call below will do anything is if the stack
620 offset is too large. In that case IND_LEVELS doesn't matter, so we
621 can just pass a zero. Adjust the type to be the address of the
622 corresponding object. If the address was valid, save the eliminated
623 address. If it wasn't valid, we need to make a reload each time, so
624 don't save it. */
626 if (! mem_valid)
628 type = (type == RELOAD_FOR_INPUT ? RELOAD_FOR_INPUT_ADDRESS
629 : type == RELOAD_FOR_OUTPUT ? RELOAD_FOR_OUTPUT_ADDRESS
630 : RELOAD_OTHER);
632 find_reloads_address (mode, &loc, XEXP (loc, 0), &XEXP (loc, 0),
633 opnum, type, 0, 0);
636 secondary_memlocs_elim[(int) mode][opnum] = loc;
637 if (secondary_memlocs_elim_used <= (int)mode)
638 secondary_memlocs_elim_used = (int)mode + 1;
639 return loc;
642 /* Clear any secondary memory locations we've made. */
644 void
645 clear_secondary_mem (void)
647 memset (secondary_memlocs, 0, sizeof secondary_memlocs);
649 #endif /* SECONDARY_MEMORY_NEEDED */
652 /* Find the largest class which has at least one register valid in
653 mode INNER, and which for every such register, that register number
654 plus N is also valid in OUTER (if in range) and is cheap to move
655 into REGNO. Such a class must exist. */
657 static enum reg_class
658 find_valid_class (enum machine_mode outer ATTRIBUTE_UNUSED,
659 enum machine_mode inner ATTRIBUTE_UNUSED, int n,
660 unsigned int dest_regno ATTRIBUTE_UNUSED)
662 int best_cost = -1;
663 int rclass;
664 int regno;
665 enum reg_class best_class = NO_REGS;
666 enum reg_class dest_class ATTRIBUTE_UNUSED = REGNO_REG_CLASS (dest_regno);
667 unsigned int best_size = 0;
668 int cost;
670 for (rclass = 1; rclass < N_REG_CLASSES; rclass++)
672 int bad = 0;
673 int good = 0;
674 for (regno = 0; regno < FIRST_PSEUDO_REGISTER - n && ! bad; regno++)
675 if (TEST_HARD_REG_BIT (reg_class_contents[rclass], regno))
677 if (HARD_REGNO_MODE_OK (regno, inner))
679 good = 1;
680 if (! TEST_HARD_REG_BIT (reg_class_contents[rclass], regno + n)
681 || ! HARD_REGNO_MODE_OK (regno + n, outer))
682 bad = 1;
686 if (bad || !good)
687 continue;
688 cost = REGISTER_MOVE_COST (outer, rclass, dest_class);
690 if ((reg_class_size[rclass] > best_size
691 && (best_cost < 0 || best_cost >= cost))
692 || best_cost > cost)
694 best_class = rclass;
695 best_size = reg_class_size[rclass];
696 best_cost = REGISTER_MOVE_COST (outer, rclass, dest_class);
700 gcc_assert (best_size != 0);
702 return best_class;
705 /* Return the number of a previously made reload that can be combined with
706 a new one, or n_reloads if none of the existing reloads can be used.
707 OUT, RCLASS, TYPE and OPNUM are the same arguments as passed to
708 push_reload, they determine the kind of the new reload that we try to
709 combine. P_IN points to the corresponding value of IN, which can be
710 modified by this function.
711 DONT_SHARE is nonzero if we can't share any input-only reload for IN. */
713 static int
714 find_reusable_reload (rtx *p_in, rtx out, enum reg_class rclass,
715 enum reload_type type, int opnum, int dont_share)
717 rtx in = *p_in;
718 int i;
719 /* We can't merge two reloads if the output of either one is
720 earlyclobbered. */
722 if (earlyclobber_operand_p (out))
723 return n_reloads;
725 /* We can use an existing reload if the class is right
726 and at least one of IN and OUT is a match
727 and the other is at worst neutral.
728 (A zero compared against anything is neutral.)
730 If SMALL_REGISTER_CLASSES, don't use existing reloads unless they are
731 for the same thing since that can cause us to need more reload registers
732 than we otherwise would. */
734 for (i = 0; i < n_reloads; i++)
735 if ((reg_class_subset_p (rclass, rld[i].rclass)
736 || reg_class_subset_p (rld[i].rclass, rclass))
737 /* If the existing reload has a register, it must fit our class. */
738 && (rld[i].reg_rtx == 0
739 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
740 true_regnum (rld[i].reg_rtx)))
741 && ((in != 0 && MATCHES (rld[i].in, in) && ! dont_share
742 && (out == 0 || rld[i].out == 0 || MATCHES (rld[i].out, out)))
743 || (out != 0 && MATCHES (rld[i].out, out)
744 && (in == 0 || rld[i].in == 0 || MATCHES (rld[i].in, in))))
745 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
746 && (SMALL_REGISTER_CLASS_P (rclass) || SMALL_REGISTER_CLASSES)
747 && MERGABLE_RELOADS (type, rld[i].when_needed, opnum, rld[i].opnum))
748 return i;
750 /* Reloading a plain reg for input can match a reload to postincrement
751 that reg, since the postincrement's value is the right value.
752 Likewise, it can match a preincrement reload, since we regard
753 the preincrementation as happening before any ref in this insn
754 to that register. */
755 for (i = 0; i < n_reloads; i++)
756 if ((reg_class_subset_p (rclass, rld[i].rclass)
757 || reg_class_subset_p (rld[i].rclass, rclass))
758 /* If the existing reload has a register, it must fit our
759 class. */
760 && (rld[i].reg_rtx == 0
761 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
762 true_regnum (rld[i].reg_rtx)))
763 && out == 0 && rld[i].out == 0 && rld[i].in != 0
764 && ((REG_P (in)
765 && GET_RTX_CLASS (GET_CODE (rld[i].in)) == RTX_AUTOINC
766 && MATCHES (XEXP (rld[i].in, 0), in))
767 || (REG_P (rld[i].in)
768 && GET_RTX_CLASS (GET_CODE (in)) == RTX_AUTOINC
769 && MATCHES (XEXP (in, 0), rld[i].in)))
770 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
771 && (SMALL_REGISTER_CLASS_P (rclass) || SMALL_REGISTER_CLASSES)
772 && MERGABLE_RELOADS (type, rld[i].when_needed,
773 opnum, rld[i].opnum))
775 /* Make sure reload_in ultimately has the increment,
776 not the plain register. */
777 if (REG_P (in))
778 *p_in = rld[i].in;
779 return i;
781 return n_reloads;
784 /* Return nonzero if X is a SUBREG which will require reloading of its
785 SUBREG_REG expression. */
787 static int
788 reload_inner_reg_of_subreg (rtx x, enum machine_mode mode, int output)
790 rtx inner;
792 /* Only SUBREGs are problematical. */
793 if (GET_CODE (x) != SUBREG)
794 return 0;
796 inner = SUBREG_REG (x);
798 /* If INNER is a constant or PLUS, then INNER must be reloaded. */
799 if (CONSTANT_P (inner) || GET_CODE (inner) == PLUS)
800 return 1;
802 /* If INNER is not a hard register, then INNER will not need to
803 be reloaded. */
804 if (!REG_P (inner)
805 || REGNO (inner) >= FIRST_PSEUDO_REGISTER)
806 return 0;
808 /* If INNER is not ok for MODE, then INNER will need reloading. */
809 if (! HARD_REGNO_MODE_OK (subreg_regno (x), mode))
810 return 1;
812 /* If the outer part is a word or smaller, INNER larger than a
813 word and the number of regs for INNER is not the same as the
814 number of words in INNER, then INNER will need reloading. */
815 return (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
816 && output
817 && GET_MODE_SIZE (GET_MODE (inner)) > UNITS_PER_WORD
818 && ((GET_MODE_SIZE (GET_MODE (inner)) / UNITS_PER_WORD)
819 != (int) hard_regno_nregs[REGNO (inner)][GET_MODE (inner)]));
822 /* Return nonzero if IN can be reloaded into REGNO with mode MODE without
823 requiring an extra reload register. The caller has already found that
824 IN contains some reference to REGNO, so check that we can produce the
825 new value in a single step. E.g. if we have
826 (set (reg r13) (plus (reg r13) (const int 1))), and there is an
827 instruction that adds one to a register, this should succeed.
828 However, if we have something like
829 (set (reg r13) (plus (reg r13) (const int 999))), and the constant 999
830 needs to be loaded into a register first, we need a separate reload
831 register.
832 Such PLUS reloads are generated by find_reload_address_part.
833 The out-of-range PLUS expressions are usually introduced in the instruction
834 patterns by register elimination and substituting pseudos without a home
835 by their function-invariant equivalences. */
836 static int
837 can_reload_into (rtx in, int regno, enum machine_mode mode)
839 rtx dst, test_insn;
840 int r = 0;
841 struct recog_data save_recog_data;
843 /* For matching constraints, we often get notional input reloads where
844 we want to use the original register as the reload register. I.e.
845 technically this is a non-optional input-output reload, but IN is
846 already a valid register, and has been chosen as the reload register.
847 Speed this up, since it trivially works. */
848 if (REG_P (in))
849 return 1;
851 /* To test MEMs properly, we'd have to take into account all the reloads
852 that are already scheduled, which can become quite complicated.
853 And since we've already handled address reloads for this MEM, it
854 should always succeed anyway. */
855 if (MEM_P (in))
856 return 1;
858 /* If we can make a simple SET insn that does the job, everything should
859 be fine. */
860 dst = gen_rtx_REG (mode, regno);
861 test_insn = make_insn_raw (gen_rtx_SET (VOIDmode, dst, in));
862 save_recog_data = recog_data;
863 if (recog_memoized (test_insn) >= 0)
865 extract_insn (test_insn);
866 r = constrain_operands (1);
868 recog_data = save_recog_data;
869 return r;
872 /* Record one reload that needs to be performed.
873 IN is an rtx saying where the data are to be found before this instruction.
874 OUT says where they must be stored after the instruction.
875 (IN is zero for data not read, and OUT is zero for data not written.)
876 INLOC and OUTLOC point to the places in the instructions where
877 IN and OUT were found.
878 If IN and OUT are both nonzero, it means the same register must be used
879 to reload both IN and OUT.
881 RCLASS is a register class required for the reloaded data.
882 INMODE is the machine mode that the instruction requires
883 for the reg that replaces IN and OUTMODE is likewise for OUT.
885 If IN is zero, then OUT's location and mode should be passed as
886 INLOC and INMODE.
888 STRICT_LOW is the 1 if there is a containing STRICT_LOW_PART rtx.
890 OPTIONAL nonzero means this reload does not need to be performed:
891 it can be discarded if that is more convenient.
893 OPNUM and TYPE say what the purpose of this reload is.
895 The return value is the reload-number for this reload.
897 If both IN and OUT are nonzero, in some rare cases we might
898 want to make two separate reloads. (Actually we never do this now.)
899 Therefore, the reload-number for OUT is stored in
900 output_reloadnum when we return; the return value applies to IN.
901 Usually (presently always), when IN and OUT are nonzero,
902 the two reload-numbers are equal, but the caller should be careful to
903 distinguish them. */
906 push_reload (rtx in, rtx out, rtx *inloc, rtx *outloc,
907 enum reg_class rclass, enum machine_mode inmode,
908 enum machine_mode outmode, int strict_low, int optional,
909 int opnum, enum reload_type type)
911 int i;
912 int dont_share = 0;
913 int dont_remove_subreg = 0;
914 rtx *in_subreg_loc = 0, *out_subreg_loc = 0;
915 int secondary_in_reload = -1, secondary_out_reload = -1;
916 enum insn_code secondary_in_icode = CODE_FOR_nothing;
917 enum insn_code secondary_out_icode = CODE_FOR_nothing;
919 /* INMODE and/or OUTMODE could be VOIDmode if no mode
920 has been specified for the operand. In that case,
921 use the operand's mode as the mode to reload. */
922 if (inmode == VOIDmode && in != 0)
923 inmode = GET_MODE (in);
924 if (outmode == VOIDmode && out != 0)
925 outmode = GET_MODE (out);
927 /* If find_reloads and friends until now missed to replace a pseudo
928 with a constant of reg_equiv_constant something went wrong
929 beforehand.
930 Note that it can't simply be done here if we missed it earlier
931 since the constant might need to be pushed into the literal pool
932 and the resulting memref would probably need further
933 reloading. */
934 if (in != 0 && REG_P (in))
936 int regno = REGNO (in);
938 gcc_assert (regno < FIRST_PSEUDO_REGISTER
939 || reg_renumber[regno] >= 0
940 || reg_equiv_constant[regno] == NULL_RTX);
943 /* reg_equiv_constant only contains constants which are obviously
944 not appropriate as destination. So if we would need to replace
945 the destination pseudo with a constant we are in real
946 trouble. */
947 if (out != 0 && REG_P (out))
949 int regno = REGNO (out);
951 gcc_assert (regno < FIRST_PSEUDO_REGISTER
952 || reg_renumber[regno] >= 0
953 || reg_equiv_constant[regno] == NULL_RTX);
956 /* If we have a read-write operand with an address side-effect,
957 change either IN or OUT so the side-effect happens only once. */
958 if (in != 0 && out != 0 && MEM_P (in) && rtx_equal_p (in, out))
959 switch (GET_CODE (XEXP (in, 0)))
961 case POST_INC: case POST_DEC: case POST_MODIFY:
962 in = replace_equiv_address_nv (in, XEXP (XEXP (in, 0), 0));
963 break;
965 case PRE_INC: case PRE_DEC: case PRE_MODIFY:
966 out = replace_equiv_address_nv (out, XEXP (XEXP (out, 0), 0));
967 break;
969 default:
970 break;
973 /* If we are reloading a (SUBREG constant ...), really reload just the
974 inside expression in its own mode. Similarly for (SUBREG (PLUS ...)).
975 If we have (SUBREG:M1 (MEM:M2 ...) ...) (or an inner REG that is still
976 a pseudo and hence will become a MEM) with M1 wider than M2 and the
977 register is a pseudo, also reload the inside expression.
978 For machines that extend byte loads, do this for any SUBREG of a pseudo
979 where both M1 and M2 are a word or smaller, M1 is wider than M2, and
980 M2 is an integral mode that gets extended when loaded.
981 Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
982 either M1 is not valid for R or M2 is wider than a word but we only
983 need one word to store an M2-sized quantity in R.
984 (However, if OUT is nonzero, we need to reload the reg *and*
985 the subreg, so do nothing here, and let following statement handle it.)
987 Note that the case of (SUBREG (CONST_INT...)...) is handled elsewhere;
988 we can't handle it here because CONST_INT does not indicate a mode.
990 Similarly, we must reload the inside expression if we have a
991 STRICT_LOW_PART (presumably, in == out in this case).
993 Also reload the inner expression if it does not require a secondary
994 reload but the SUBREG does.
996 Finally, reload the inner expression if it is a register that is in
997 the class whose registers cannot be referenced in a different size
998 and M1 is not the same size as M2. If subreg_lowpart_p is false, we
999 cannot reload just the inside since we might end up with the wrong
1000 register class. But if it is inside a STRICT_LOW_PART, we have
1001 no choice, so we hope we do get the right register class there. */
1003 if (in != 0 && GET_CODE (in) == SUBREG
1004 && (subreg_lowpart_p (in) || strict_low)
1005 #ifdef CANNOT_CHANGE_MODE_CLASS
1006 && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SUBREG_REG (in)), inmode, rclass)
1007 #endif
1008 && (CONSTANT_P (SUBREG_REG (in))
1009 || GET_CODE (SUBREG_REG (in)) == PLUS
1010 || strict_low
1011 || (((REG_P (SUBREG_REG (in))
1012 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER)
1013 || MEM_P (SUBREG_REG (in)))
1014 && ((GET_MODE_SIZE (inmode)
1015 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1016 #ifdef LOAD_EXTEND_OP
1017 || (GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1018 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1019 <= UNITS_PER_WORD)
1020 && (GET_MODE_SIZE (inmode)
1021 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1022 && INTEGRAL_MODE_P (GET_MODE (SUBREG_REG (in)))
1023 && LOAD_EXTEND_OP (GET_MODE (SUBREG_REG (in))) != UNKNOWN)
1024 #endif
1025 #ifdef WORD_REGISTER_OPERATIONS
1026 || ((GET_MODE_SIZE (inmode)
1027 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
1028 && ((GET_MODE_SIZE (inmode) - 1) / UNITS_PER_WORD ==
1029 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))) - 1)
1030 / UNITS_PER_WORD)))
1031 #endif
1033 || (REG_P (SUBREG_REG (in))
1034 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1035 /* The case where out is nonzero
1036 is handled differently in the following statement. */
1037 && (out == 0 || subreg_lowpart_p (in))
1038 && ((GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1039 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1040 > UNITS_PER_WORD)
1041 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1042 / UNITS_PER_WORD)
1043 != (int) hard_regno_nregs[REGNO (SUBREG_REG (in))]
1044 [GET_MODE (SUBREG_REG (in))]))
1045 || ! HARD_REGNO_MODE_OK (subreg_regno (in), inmode)))
1046 || (secondary_reload_class (1, rclass, inmode, in) != NO_REGS
1047 && (secondary_reload_class (1, rclass, GET_MODE (SUBREG_REG (in)),
1048 SUBREG_REG (in))
1049 == NO_REGS))
1050 #ifdef CANNOT_CHANGE_MODE_CLASS
1051 || (REG_P (SUBREG_REG (in))
1052 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1053 && REG_CANNOT_CHANGE_MODE_P
1054 (REGNO (SUBREG_REG (in)), GET_MODE (SUBREG_REG (in)), inmode))
1055 #endif
1058 in_subreg_loc = inloc;
1059 inloc = &SUBREG_REG (in);
1060 in = *inloc;
1061 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
1062 if (MEM_P (in))
1063 /* This is supposed to happen only for paradoxical subregs made by
1064 combine.c. (SUBREG (MEM)) isn't supposed to occur other ways. */
1065 gcc_assert (GET_MODE_SIZE (GET_MODE (in)) <= GET_MODE_SIZE (inmode));
1066 #endif
1067 inmode = GET_MODE (in);
1070 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
1071 either M1 is not valid for R or M2 is wider than a word but we only
1072 need one word to store an M2-sized quantity in R.
1074 However, we must reload the inner reg *as well as* the subreg in
1075 that case. */
1077 /* Similar issue for (SUBREG constant ...) if it was not handled by the
1078 code above. This can happen if SUBREG_BYTE != 0. */
1080 if (in != 0 && reload_inner_reg_of_subreg (in, inmode, 0))
1082 enum reg_class in_class = rclass;
1084 if (REG_P (SUBREG_REG (in)))
1085 in_class
1086 = find_valid_class (inmode, GET_MODE (SUBREG_REG (in)),
1087 subreg_regno_offset (REGNO (SUBREG_REG (in)),
1088 GET_MODE (SUBREG_REG (in)),
1089 SUBREG_BYTE (in),
1090 GET_MODE (in)),
1091 REGNO (SUBREG_REG (in)));
1093 /* This relies on the fact that emit_reload_insns outputs the
1094 instructions for input reloads of type RELOAD_OTHER in the same
1095 order as the reloads. Thus if the outer reload is also of type
1096 RELOAD_OTHER, we are guaranteed that this inner reload will be
1097 output before the outer reload. */
1098 push_reload (SUBREG_REG (in), NULL_RTX, &SUBREG_REG (in), (rtx *) 0,
1099 in_class, VOIDmode, VOIDmode, 0, 0, opnum, type);
1100 dont_remove_subreg = 1;
1103 /* Similarly for paradoxical and problematical SUBREGs on the output.
1104 Note that there is no reason we need worry about the previous value
1105 of SUBREG_REG (out); even if wider than out,
1106 storing in a subreg is entitled to clobber it all
1107 (except in the case of STRICT_LOW_PART,
1108 and in that case the constraint should label it input-output.) */
1109 if (out != 0 && GET_CODE (out) == SUBREG
1110 && (subreg_lowpart_p (out) || strict_low)
1111 #ifdef CANNOT_CHANGE_MODE_CLASS
1112 && !CANNOT_CHANGE_MODE_CLASS (GET_MODE (SUBREG_REG (out)), outmode, rclass)
1113 #endif
1114 && (CONSTANT_P (SUBREG_REG (out))
1115 || strict_low
1116 || (((REG_P (SUBREG_REG (out))
1117 && REGNO (SUBREG_REG (out)) >= FIRST_PSEUDO_REGISTER)
1118 || MEM_P (SUBREG_REG (out)))
1119 && ((GET_MODE_SIZE (outmode)
1120 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1121 #ifdef WORD_REGISTER_OPERATIONS
1122 || ((GET_MODE_SIZE (outmode)
1123 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
1124 && ((GET_MODE_SIZE (outmode) - 1) / UNITS_PER_WORD ==
1125 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))) - 1)
1126 / UNITS_PER_WORD)))
1127 #endif
1129 || (REG_P (SUBREG_REG (out))
1130 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1131 && ((GET_MODE_SIZE (outmode) <= UNITS_PER_WORD
1132 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1133 > UNITS_PER_WORD)
1134 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1135 / UNITS_PER_WORD)
1136 != (int) hard_regno_nregs[REGNO (SUBREG_REG (out))]
1137 [GET_MODE (SUBREG_REG (out))]))
1138 || ! HARD_REGNO_MODE_OK (subreg_regno (out), outmode)))
1139 || (secondary_reload_class (0, rclass, outmode, out) != NO_REGS
1140 && (secondary_reload_class (0, rclass, GET_MODE (SUBREG_REG (out)),
1141 SUBREG_REG (out))
1142 == NO_REGS))
1143 #ifdef CANNOT_CHANGE_MODE_CLASS
1144 || (REG_P (SUBREG_REG (out))
1145 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1146 && REG_CANNOT_CHANGE_MODE_P (REGNO (SUBREG_REG (out)),
1147 GET_MODE (SUBREG_REG (out)),
1148 outmode))
1149 #endif
1152 out_subreg_loc = outloc;
1153 outloc = &SUBREG_REG (out);
1154 out = *outloc;
1155 #if ! defined (LOAD_EXTEND_OP) && ! defined (WORD_REGISTER_OPERATIONS)
1156 gcc_assert (!MEM_P (out)
1157 || GET_MODE_SIZE (GET_MODE (out))
1158 <= GET_MODE_SIZE (outmode));
1159 #endif
1160 outmode = GET_MODE (out);
1163 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R where
1164 either M1 is not valid for R or M2 is wider than a word but we only
1165 need one word to store an M2-sized quantity in R.
1167 However, we must reload the inner reg *as well as* the subreg in
1168 that case. In this case, the inner reg is an in-out reload. */
1170 if (out != 0 && reload_inner_reg_of_subreg (out, outmode, 1))
1172 /* This relies on the fact that emit_reload_insns outputs the
1173 instructions for output reloads of type RELOAD_OTHER in reverse
1174 order of the reloads. Thus if the outer reload is also of type
1175 RELOAD_OTHER, we are guaranteed that this inner reload will be
1176 output after the outer reload. */
1177 dont_remove_subreg = 1;
1178 push_reload (SUBREG_REG (out), SUBREG_REG (out), &SUBREG_REG (out),
1179 &SUBREG_REG (out),
1180 find_valid_class (outmode, GET_MODE (SUBREG_REG (out)),
1181 subreg_regno_offset (REGNO (SUBREG_REG (out)),
1182 GET_MODE (SUBREG_REG (out)),
1183 SUBREG_BYTE (out),
1184 GET_MODE (out)),
1185 REGNO (SUBREG_REG (out))),
1186 VOIDmode, VOIDmode, 0, 0,
1187 opnum, RELOAD_OTHER);
1190 /* If IN appears in OUT, we can't share any input-only reload for IN. */
1191 if (in != 0 && out != 0 && MEM_P (out)
1192 && (REG_P (in) || MEM_P (in) || GET_CODE (in) == PLUS)
1193 && reg_overlap_mentioned_for_reload_p (in, XEXP (out, 0)))
1194 dont_share = 1;
1196 /* If IN is a SUBREG of a hard register, make a new REG. This
1197 simplifies some of the cases below. */
1199 if (in != 0 && GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))
1200 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1201 && ! dont_remove_subreg)
1202 in = gen_rtx_REG (GET_MODE (in), subreg_regno (in));
1204 /* Similarly for OUT. */
1205 if (out != 0 && GET_CODE (out) == SUBREG
1206 && REG_P (SUBREG_REG (out))
1207 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1208 && ! dont_remove_subreg)
1209 out = gen_rtx_REG (GET_MODE (out), subreg_regno (out));
1211 /* Narrow down the class of register wanted if that is
1212 desirable on this machine for efficiency. */
1214 enum reg_class preferred_class = rclass;
1216 if (in != 0)
1217 preferred_class = PREFERRED_RELOAD_CLASS (in, rclass);
1219 /* Output reloads may need analogous treatment, different in detail. */
1220 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
1221 if (out != 0)
1222 preferred_class = PREFERRED_OUTPUT_RELOAD_CLASS (out, preferred_class);
1223 #endif
1225 /* Discard what the target said if we cannot do it. */
1226 if (preferred_class != NO_REGS
1227 || (optional && type == RELOAD_FOR_OUTPUT))
1228 rclass = preferred_class;
1231 /* Make sure we use a class that can handle the actual pseudo
1232 inside any subreg. For example, on the 386, QImode regs
1233 can appear within SImode subregs. Although GENERAL_REGS
1234 can handle SImode, QImode needs a smaller class. */
1235 #ifdef LIMIT_RELOAD_CLASS
1236 if (in_subreg_loc)
1237 rclass = LIMIT_RELOAD_CLASS (inmode, rclass);
1238 else if (in != 0 && GET_CODE (in) == SUBREG)
1239 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (in)), rclass);
1241 if (out_subreg_loc)
1242 rclass = LIMIT_RELOAD_CLASS (outmode, rclass);
1243 if (out != 0 && GET_CODE (out) == SUBREG)
1244 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (out)), rclass);
1245 #endif
1247 /* Verify that this class is at least possible for the mode that
1248 is specified. */
1249 if (this_insn_is_asm)
1251 enum machine_mode mode;
1252 if (GET_MODE_SIZE (inmode) > GET_MODE_SIZE (outmode))
1253 mode = inmode;
1254 else
1255 mode = outmode;
1256 if (mode == VOIDmode)
1258 error_for_asm (this_insn, "cannot reload integer constant "
1259 "operand in %<asm%>");
1260 mode = word_mode;
1261 if (in != 0)
1262 inmode = word_mode;
1263 if (out != 0)
1264 outmode = word_mode;
1266 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1267 if (HARD_REGNO_MODE_OK (i, mode)
1268 && in_hard_reg_set_p (reg_class_contents[(int) rclass], mode, i))
1269 break;
1270 if (i == FIRST_PSEUDO_REGISTER)
1272 error_for_asm (this_insn, "impossible register constraint "
1273 "in %<asm%>");
1274 /* Avoid further trouble with this insn. */
1275 PATTERN (this_insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1276 /* We used to continue here setting class to ALL_REGS, but it triggers
1277 sanity check on i386 for:
1278 void foo(long double d)
1280 asm("" :: "a" (d));
1282 Returning zero here ought to be safe as we take care in
1283 find_reloads to not process the reloads when instruction was
1284 replaced by USE. */
1286 return 0;
1290 /* Optional output reloads are always OK even if we have no register class,
1291 since the function of these reloads is only to have spill_reg_store etc.
1292 set, so that the storing insn can be deleted later. */
1293 gcc_assert (rclass != NO_REGS
1294 || (optional != 0 && type == RELOAD_FOR_OUTPUT));
1296 i = find_reusable_reload (&in, out, rclass, type, opnum, dont_share);
1298 if (i == n_reloads)
1300 /* See if we need a secondary reload register to move between CLASS
1301 and IN or CLASS and OUT. Get the icode and push any required reloads
1302 needed for each of them if so. */
1304 if (in != 0)
1305 secondary_in_reload
1306 = push_secondary_reload (1, in, opnum, optional, rclass, inmode, type,
1307 &secondary_in_icode, NULL);
1308 if (out != 0 && GET_CODE (out) != SCRATCH)
1309 secondary_out_reload
1310 = push_secondary_reload (0, out, opnum, optional, rclass, outmode,
1311 type, &secondary_out_icode, NULL);
1313 /* We found no existing reload suitable for re-use.
1314 So add an additional reload. */
1316 #ifdef SECONDARY_MEMORY_NEEDED
1317 /* If a memory location is needed for the copy, make one. */
1318 if (in != 0
1319 && (REG_P (in)
1320 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))))
1321 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
1322 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
1323 rclass, inmode))
1324 get_secondary_mem (in, inmode, opnum, type);
1325 #endif
1327 i = n_reloads;
1328 rld[i].in = in;
1329 rld[i].out = out;
1330 rld[i].rclass = rclass;
1331 rld[i].inmode = inmode;
1332 rld[i].outmode = outmode;
1333 rld[i].reg_rtx = 0;
1334 rld[i].optional = optional;
1335 rld[i].inc = 0;
1336 rld[i].nocombine = 0;
1337 rld[i].in_reg = inloc ? *inloc : 0;
1338 rld[i].out_reg = outloc ? *outloc : 0;
1339 rld[i].opnum = opnum;
1340 rld[i].when_needed = type;
1341 rld[i].secondary_in_reload = secondary_in_reload;
1342 rld[i].secondary_out_reload = secondary_out_reload;
1343 rld[i].secondary_in_icode = secondary_in_icode;
1344 rld[i].secondary_out_icode = secondary_out_icode;
1345 rld[i].secondary_p = 0;
1347 n_reloads++;
1349 #ifdef SECONDARY_MEMORY_NEEDED
1350 if (out != 0
1351 && (REG_P (out)
1352 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out))))
1353 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
1354 && SECONDARY_MEMORY_NEEDED (rclass,
1355 REGNO_REG_CLASS (reg_or_subregno (out)),
1356 outmode))
1357 get_secondary_mem (out, outmode, opnum, type);
1358 #endif
1360 else
1362 /* We are reusing an existing reload,
1363 but we may have additional information for it.
1364 For example, we may now have both IN and OUT
1365 while the old one may have just one of them. */
1367 /* The modes can be different. If they are, we want to reload in
1368 the larger mode, so that the value is valid for both modes. */
1369 if (inmode != VOIDmode
1370 && GET_MODE_SIZE (inmode) > GET_MODE_SIZE (rld[i].inmode))
1371 rld[i].inmode = inmode;
1372 if (outmode != VOIDmode
1373 && GET_MODE_SIZE (outmode) > GET_MODE_SIZE (rld[i].outmode))
1374 rld[i].outmode = outmode;
1375 if (in != 0)
1377 rtx in_reg = inloc ? *inloc : 0;
1378 /* If we merge reloads for two distinct rtl expressions that
1379 are identical in content, there might be duplicate address
1380 reloads. Remove the extra set now, so that if we later find
1381 that we can inherit this reload, we can get rid of the
1382 address reloads altogether.
1384 Do not do this if both reloads are optional since the result
1385 would be an optional reload which could potentially leave
1386 unresolved address replacements.
1388 It is not sufficient to call transfer_replacements since
1389 choose_reload_regs will remove the replacements for address
1390 reloads of inherited reloads which results in the same
1391 problem. */
1392 if (rld[i].in != in && rtx_equal_p (in, rld[i].in)
1393 && ! (rld[i].optional && optional))
1395 /* We must keep the address reload with the lower operand
1396 number alive. */
1397 if (opnum > rld[i].opnum)
1399 remove_address_replacements (in);
1400 in = rld[i].in;
1401 in_reg = rld[i].in_reg;
1403 else
1404 remove_address_replacements (rld[i].in);
1406 /* When emitting reloads we don't necessarily look at the in-
1407 and outmode, but also directly at the operands (in and out).
1408 So we can't simply overwrite them with whatever we have found
1409 for this (to-be-merged) reload, we have to "merge" that too.
1410 Reusing another reload already verified that we deal with the
1411 same operands, just possibly in different modes. So we
1412 overwrite the operands only when the new mode is larger.
1413 See also PR33613. */
1414 if (!rld[i].in
1415 || GET_MODE_SIZE (GET_MODE (in))
1416 > GET_MODE_SIZE (GET_MODE (rld[i].in)))
1417 rld[i].in = in;
1418 if (!rld[i].in_reg
1419 || (in_reg
1420 && GET_MODE_SIZE (GET_MODE (in_reg))
1421 > GET_MODE_SIZE (GET_MODE (rld[i].in_reg))))
1422 rld[i].in_reg = in_reg;
1424 if (out != 0)
1426 if (!rld[i].out
1427 || (out
1428 && GET_MODE_SIZE (GET_MODE (out))
1429 > GET_MODE_SIZE (GET_MODE (rld[i].out))))
1430 rld[i].out = out;
1431 if (outloc
1432 && (!rld[i].out_reg
1433 || GET_MODE_SIZE (GET_MODE (*outloc))
1434 > GET_MODE_SIZE (GET_MODE (rld[i].out_reg))))
1435 rld[i].out_reg = *outloc;
1437 if (reg_class_subset_p (rclass, rld[i].rclass))
1438 rld[i].rclass = rclass;
1439 rld[i].optional &= optional;
1440 if (MERGE_TO_OTHER (type, rld[i].when_needed,
1441 opnum, rld[i].opnum))
1442 rld[i].when_needed = RELOAD_OTHER;
1443 rld[i].opnum = MIN (rld[i].opnum, opnum);
1446 /* If the ostensible rtx being reloaded differs from the rtx found
1447 in the location to substitute, this reload is not safe to combine
1448 because we cannot reliably tell whether it appears in the insn. */
1450 if (in != 0 && in != *inloc)
1451 rld[i].nocombine = 1;
1453 #if 0
1454 /* This was replaced by changes in find_reloads_address_1 and the new
1455 function inc_for_reload, which go with a new meaning of reload_inc. */
1457 /* If this is an IN/OUT reload in an insn that sets the CC,
1458 it must be for an autoincrement. It doesn't work to store
1459 the incremented value after the insn because that would clobber the CC.
1460 So we must do the increment of the value reloaded from,
1461 increment it, store it back, then decrement again. */
1462 if (out != 0 && sets_cc0_p (PATTERN (this_insn)))
1464 out = 0;
1465 rld[i].out = 0;
1466 rld[i].inc = find_inc_amount (PATTERN (this_insn), in);
1467 /* If we did not find a nonzero amount-to-increment-by,
1468 that contradicts the belief that IN is being incremented
1469 in an address in this insn. */
1470 gcc_assert (rld[i].inc != 0);
1472 #endif
1474 /* If we will replace IN and OUT with the reload-reg,
1475 record where they are located so that substitution need
1476 not do a tree walk. */
1478 if (replace_reloads)
1480 if (inloc != 0)
1482 struct replacement *r = &replacements[n_replacements++];
1483 r->what = i;
1484 r->subreg_loc = in_subreg_loc;
1485 r->where = inloc;
1486 r->mode = inmode;
1488 if (outloc != 0 && outloc != inloc)
1490 struct replacement *r = &replacements[n_replacements++];
1491 r->what = i;
1492 r->where = outloc;
1493 r->subreg_loc = out_subreg_loc;
1494 r->mode = outmode;
1498 /* If this reload is just being introduced and it has both
1499 an incoming quantity and an outgoing quantity that are
1500 supposed to be made to match, see if either one of the two
1501 can serve as the place to reload into.
1503 If one of them is acceptable, set rld[i].reg_rtx
1504 to that one. */
1506 if (in != 0 && out != 0 && in != out && rld[i].reg_rtx == 0)
1508 rld[i].reg_rtx = find_dummy_reload (in, out, inloc, outloc,
1509 inmode, outmode,
1510 rld[i].rclass, i,
1511 earlyclobber_operand_p (out));
1513 /* If the outgoing register already contains the same value
1514 as the incoming one, we can dispense with loading it.
1515 The easiest way to tell the caller that is to give a phony
1516 value for the incoming operand (same as outgoing one). */
1517 if (rld[i].reg_rtx == out
1518 && (REG_P (in) || CONSTANT_P (in))
1519 && 0 != find_equiv_reg (in, this_insn, 0, REGNO (out),
1520 static_reload_reg_p, i, inmode))
1521 rld[i].in = out;
1524 /* If this is an input reload and the operand contains a register that
1525 dies in this insn and is used nowhere else, see if it is the right class
1526 to be used for this reload. Use it if so. (This occurs most commonly
1527 in the case of paradoxical SUBREGs and in-out reloads). We cannot do
1528 this if it is also an output reload that mentions the register unless
1529 the output is a SUBREG that clobbers an entire register.
1531 Note that the operand might be one of the spill regs, if it is a
1532 pseudo reg and we are in a block where spilling has not taken place.
1533 But if there is no spilling in this block, that is OK.
1534 An explicitly used hard reg cannot be a spill reg. */
1536 if (rld[i].reg_rtx == 0 && in != 0 && hard_regs_live_known)
1538 rtx note;
1539 int regno;
1540 enum machine_mode rel_mode = inmode;
1542 if (out && GET_MODE_SIZE (outmode) > GET_MODE_SIZE (inmode))
1543 rel_mode = outmode;
1545 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1546 if (REG_NOTE_KIND (note) == REG_DEAD
1547 && REG_P (XEXP (note, 0))
1548 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1549 && reg_mentioned_p (XEXP (note, 0), in)
1550 /* Check that a former pseudo is valid; see find_dummy_reload. */
1551 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1552 || (!bitmap_bit_p (DF_LIVE_OUT (ENTRY_BLOCK_PTR),
1553 ORIGINAL_REGNO (XEXP (note, 0)))
1554 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1))
1555 && ! refers_to_regno_for_reload_p (regno,
1556 end_hard_regno (rel_mode,
1557 regno),
1558 PATTERN (this_insn), inloc)
1559 /* If this is also an output reload, IN cannot be used as
1560 the reload register if it is set in this insn unless IN
1561 is also OUT. */
1562 && (out == 0 || in == out
1563 || ! hard_reg_set_here_p (regno,
1564 end_hard_regno (rel_mode, regno),
1565 PATTERN (this_insn)))
1566 /* ??? Why is this code so different from the previous?
1567 Is there any simple coherent way to describe the two together?
1568 What's going on here. */
1569 && (in != out
1570 || (GET_CODE (in) == SUBREG
1571 && (((GET_MODE_SIZE (GET_MODE (in)) + (UNITS_PER_WORD - 1))
1572 / UNITS_PER_WORD)
1573 == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1574 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
1575 /* Make sure the operand fits in the reg that dies. */
1576 && (GET_MODE_SIZE (rel_mode)
1577 <= GET_MODE_SIZE (GET_MODE (XEXP (note, 0))))
1578 && HARD_REGNO_MODE_OK (regno, inmode)
1579 && HARD_REGNO_MODE_OK (regno, outmode))
1581 unsigned int offs;
1582 unsigned int nregs = MAX (hard_regno_nregs[regno][inmode],
1583 hard_regno_nregs[regno][outmode]);
1585 for (offs = 0; offs < nregs; offs++)
1586 if (fixed_regs[regno + offs]
1587 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1588 regno + offs))
1589 break;
1591 if (offs == nregs
1592 && (! (refers_to_regno_for_reload_p
1593 (regno, end_hard_regno (inmode, regno), in, (rtx *) 0))
1594 || can_reload_into (in, regno, inmode)))
1596 rld[i].reg_rtx = gen_rtx_REG (rel_mode, regno);
1597 break;
1602 if (out)
1603 output_reloadnum = i;
1605 return i;
1608 /* Record an additional place we must replace a value
1609 for which we have already recorded a reload.
1610 RELOADNUM is the value returned by push_reload
1611 when the reload was recorded.
1612 This is used in insn patterns that use match_dup. */
1614 static void
1615 push_replacement (rtx *loc, int reloadnum, enum machine_mode mode)
1617 if (replace_reloads)
1619 struct replacement *r = &replacements[n_replacements++];
1620 r->what = reloadnum;
1621 r->where = loc;
1622 r->subreg_loc = 0;
1623 r->mode = mode;
1627 /* Duplicate any replacement we have recorded to apply at
1628 location ORIG_LOC to also be performed at DUP_LOC.
1629 This is used in insn patterns that use match_dup. */
1631 static void
1632 dup_replacements (rtx *dup_loc, rtx *orig_loc)
1634 int i, n = n_replacements;
1636 for (i = 0; i < n; i++)
1638 struct replacement *r = &replacements[i];
1639 if (r->where == orig_loc)
1640 push_replacement (dup_loc, r->what, r->mode);
1644 /* Transfer all replacements that used to be in reload FROM to be in
1645 reload TO. */
1647 void
1648 transfer_replacements (int to, int from)
1650 int i;
1652 for (i = 0; i < n_replacements; i++)
1653 if (replacements[i].what == from)
1654 replacements[i].what = to;
1657 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1658 or a subpart of it. If we have any replacements registered for IN_RTX,
1659 cancel the reloads that were supposed to load them.
1660 Return nonzero if we canceled any reloads. */
1662 remove_address_replacements (rtx in_rtx)
1664 int i, j;
1665 char reload_flags[MAX_RELOADS];
1666 int something_changed = 0;
1668 memset (reload_flags, 0, sizeof reload_flags);
1669 for (i = 0, j = 0; i < n_replacements; i++)
1671 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1672 reload_flags[replacements[i].what] |= 1;
1673 else
1675 replacements[j++] = replacements[i];
1676 reload_flags[replacements[i].what] |= 2;
1679 /* Note that the following store must be done before the recursive calls. */
1680 n_replacements = j;
1682 for (i = n_reloads - 1; i >= 0; i--)
1684 if (reload_flags[i] == 1)
1686 deallocate_reload_reg (i);
1687 remove_address_replacements (rld[i].in);
1688 rld[i].in = 0;
1689 something_changed = 1;
1692 return something_changed;
1695 /* If there is only one output reload, and it is not for an earlyclobber
1696 operand, try to combine it with a (logically unrelated) input reload
1697 to reduce the number of reload registers needed.
1699 This is safe if the input reload does not appear in
1700 the value being output-reloaded, because this implies
1701 it is not needed any more once the original insn completes.
1703 If that doesn't work, see we can use any of the registers that
1704 die in this insn as a reload register. We can if it is of the right
1705 class and does not appear in the value being output-reloaded. */
1707 static void
1708 combine_reloads (void)
1710 int i, regno;
1711 int output_reload = -1;
1712 int secondary_out = -1;
1713 rtx note;
1715 /* Find the output reload; return unless there is exactly one
1716 and that one is mandatory. */
1718 for (i = 0; i < n_reloads; i++)
1719 if (rld[i].out != 0)
1721 if (output_reload >= 0)
1722 return;
1723 output_reload = i;
1726 if (output_reload < 0 || rld[output_reload].optional)
1727 return;
1729 /* An input-output reload isn't combinable. */
1731 if (rld[output_reload].in != 0)
1732 return;
1734 /* If this reload is for an earlyclobber operand, we can't do anything. */
1735 if (earlyclobber_operand_p (rld[output_reload].out))
1736 return;
1738 /* If there is a reload for part of the address of this operand, we would
1739 need to change it to RELOAD_FOR_OTHER_ADDRESS. But that would extend
1740 its life to the point where doing this combine would not lower the
1741 number of spill registers needed. */
1742 for (i = 0; i < n_reloads; i++)
1743 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
1744 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
1745 && rld[i].opnum == rld[output_reload].opnum)
1746 return;
1748 /* Check each input reload; can we combine it? */
1750 for (i = 0; i < n_reloads; i++)
1751 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1752 /* Life span of this reload must not extend past main insn. */
1753 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1754 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1755 && rld[i].when_needed != RELOAD_OTHER
1756 && (CLASS_MAX_NREGS (rld[i].rclass, rld[i].inmode)
1757 == CLASS_MAX_NREGS (rld[output_reload].rclass,
1758 rld[output_reload].outmode))
1759 && rld[i].inc == 0
1760 && rld[i].reg_rtx == 0
1761 #ifdef SECONDARY_MEMORY_NEEDED
1762 /* Don't combine two reloads with different secondary
1763 memory locations. */
1764 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1765 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1766 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1767 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1768 #endif
1769 && (SMALL_REGISTER_CLASSES
1770 ? (rld[i].rclass == rld[output_reload].rclass)
1771 : (reg_class_subset_p (rld[i].rclass,
1772 rld[output_reload].rclass)
1773 || reg_class_subset_p (rld[output_reload].rclass,
1774 rld[i].rclass)))
1775 && (MATCHES (rld[i].in, rld[output_reload].out)
1776 /* Args reversed because the first arg seems to be
1777 the one that we imagine being modified
1778 while the second is the one that might be affected. */
1779 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1780 rld[i].in)
1781 /* However, if the input is a register that appears inside
1782 the output, then we also can't share.
1783 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1784 If the same reload reg is used for both reg 69 and the
1785 result to be stored in memory, then that result
1786 will clobber the address of the memory ref. */
1787 && ! (REG_P (rld[i].in)
1788 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1789 rld[output_reload].out))))
1790 && ! reload_inner_reg_of_subreg (rld[i].in, rld[i].inmode,
1791 rld[i].when_needed != RELOAD_FOR_INPUT)
1792 && (reg_class_size[(int) rld[i].rclass]
1793 || SMALL_REGISTER_CLASSES)
1794 /* We will allow making things slightly worse by combining an
1795 input and an output, but no worse than that. */
1796 && (rld[i].when_needed == RELOAD_FOR_INPUT
1797 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1799 int j;
1801 /* We have found a reload to combine with! */
1802 rld[i].out = rld[output_reload].out;
1803 rld[i].out_reg = rld[output_reload].out_reg;
1804 rld[i].outmode = rld[output_reload].outmode;
1805 /* Mark the old output reload as inoperative. */
1806 rld[output_reload].out = 0;
1807 /* The combined reload is needed for the entire insn. */
1808 rld[i].when_needed = RELOAD_OTHER;
1809 /* If the output reload had a secondary reload, copy it. */
1810 if (rld[output_reload].secondary_out_reload != -1)
1812 rld[i].secondary_out_reload
1813 = rld[output_reload].secondary_out_reload;
1814 rld[i].secondary_out_icode
1815 = rld[output_reload].secondary_out_icode;
1818 #ifdef SECONDARY_MEMORY_NEEDED
1819 /* Copy any secondary MEM. */
1820 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1821 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1822 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1823 #endif
1824 /* If required, minimize the register class. */
1825 if (reg_class_subset_p (rld[output_reload].rclass,
1826 rld[i].rclass))
1827 rld[i].rclass = rld[output_reload].rclass;
1829 /* Transfer all replacements from the old reload to the combined. */
1830 for (j = 0; j < n_replacements; j++)
1831 if (replacements[j].what == output_reload)
1832 replacements[j].what = i;
1834 return;
1837 /* If this insn has only one operand that is modified or written (assumed
1838 to be the first), it must be the one corresponding to this reload. It
1839 is safe to use anything that dies in this insn for that output provided
1840 that it does not occur in the output (we already know it isn't an
1841 earlyclobber. If this is an asm insn, give up. */
1843 if (INSN_CODE (this_insn) == -1)
1844 return;
1846 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1847 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1848 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1849 return;
1851 /* See if some hard register that dies in this insn and is not used in
1852 the output is the right class. Only works if the register we pick
1853 up can fully hold our output reload. */
1854 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1855 if (REG_NOTE_KIND (note) == REG_DEAD
1856 && REG_P (XEXP (note, 0))
1857 && !reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1858 rld[output_reload].out)
1859 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1860 && HARD_REGNO_MODE_OK (regno, rld[output_reload].outmode)
1861 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].rclass],
1862 regno)
1863 && (hard_regno_nregs[regno][rld[output_reload].outmode]
1864 <= hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))])
1865 /* Ensure that a secondary or tertiary reload for this output
1866 won't want this register. */
1867 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1868 || (!(TEST_HARD_REG_BIT
1869 (reg_class_contents[(int) rld[secondary_out].rclass], regno))
1870 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1871 || !(TEST_HARD_REG_BIT
1872 (reg_class_contents[(int) rld[secondary_out].rclass],
1873 regno)))))
1874 && !fixed_regs[regno]
1875 /* Check that a former pseudo is valid; see find_dummy_reload. */
1876 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1877 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR),
1878 ORIGINAL_REGNO (XEXP (note, 0)))
1879 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1)))
1881 rld[output_reload].reg_rtx
1882 = gen_rtx_REG (rld[output_reload].outmode, regno);
1883 return;
1887 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1888 See if one of IN and OUT is a register that may be used;
1889 this is desirable since a spill-register won't be needed.
1890 If so, return the register rtx that proves acceptable.
1892 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1893 RCLASS is the register class required for the reload.
1895 If FOR_REAL is >= 0, it is the number of the reload,
1896 and in some cases when it can be discovered that OUT doesn't need
1897 to be computed, clear out rld[FOR_REAL].out.
1899 If FOR_REAL is -1, this should not be done, because this call
1900 is just to see if a register can be found, not to find and install it.
1902 EARLYCLOBBER is nonzero if OUT is an earlyclobber operand. This
1903 puts an additional constraint on being able to use IN for OUT since
1904 IN must not appear elsewhere in the insn (it is assumed that IN itself
1905 is safe from the earlyclobber). */
1907 static rtx
1908 find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc,
1909 enum machine_mode inmode, enum machine_mode outmode,
1910 enum reg_class rclass, int for_real, int earlyclobber)
1912 rtx in = real_in;
1913 rtx out = real_out;
1914 int in_offset = 0;
1915 int out_offset = 0;
1916 rtx value = 0;
1918 /* If operands exceed a word, we can't use either of them
1919 unless they have the same size. */
1920 if (GET_MODE_SIZE (outmode) != GET_MODE_SIZE (inmode)
1921 && (GET_MODE_SIZE (outmode) > UNITS_PER_WORD
1922 || GET_MODE_SIZE (inmode) > UNITS_PER_WORD))
1923 return 0;
1925 /* Note that {in,out}_offset are needed only when 'in' or 'out'
1926 respectively refers to a hard register. */
1928 /* Find the inside of any subregs. */
1929 while (GET_CODE (out) == SUBREG)
1931 if (REG_P (SUBREG_REG (out))
1932 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER)
1933 out_offset += subreg_regno_offset (REGNO (SUBREG_REG (out)),
1934 GET_MODE (SUBREG_REG (out)),
1935 SUBREG_BYTE (out),
1936 GET_MODE (out));
1937 out = SUBREG_REG (out);
1939 while (GET_CODE (in) == SUBREG)
1941 if (REG_P (SUBREG_REG (in))
1942 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER)
1943 in_offset += subreg_regno_offset (REGNO (SUBREG_REG (in)),
1944 GET_MODE (SUBREG_REG (in)),
1945 SUBREG_BYTE (in),
1946 GET_MODE (in));
1947 in = SUBREG_REG (in);
1950 /* Narrow down the reg class, the same way push_reload will;
1951 otherwise we might find a dummy now, but push_reload won't. */
1953 enum reg_class preferred_class = PREFERRED_RELOAD_CLASS (in, rclass);
1954 if (preferred_class != NO_REGS)
1955 rclass = preferred_class;
1958 /* See if OUT will do. */
1959 if (REG_P (out)
1960 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1962 unsigned int regno = REGNO (out) + out_offset;
1963 unsigned int nwords = hard_regno_nregs[regno][outmode];
1964 rtx saved_rtx;
1966 /* When we consider whether the insn uses OUT,
1967 ignore references within IN. They don't prevent us
1968 from copying IN into OUT, because those refs would
1969 move into the insn that reloads IN.
1971 However, we only ignore IN in its role as this reload.
1972 If the insn uses IN elsewhere and it contains OUT,
1973 that counts. We can't be sure it's the "same" operand
1974 so it might not go through this reload. */
1975 saved_rtx = *inloc;
1976 *inloc = const0_rtx;
1978 if (regno < FIRST_PSEUDO_REGISTER
1979 && HARD_REGNO_MODE_OK (regno, outmode)
1980 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
1981 PATTERN (this_insn), outloc))
1983 unsigned int i;
1985 for (i = 0; i < nwords; i++)
1986 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1987 regno + i))
1988 break;
1990 if (i == nwords)
1992 if (REG_P (real_out))
1993 value = real_out;
1994 else
1995 value = gen_rtx_REG (outmode, regno);
1999 *inloc = saved_rtx;
2002 /* Consider using IN if OUT was not acceptable
2003 or if OUT dies in this insn (like the quotient in a divmod insn).
2004 We can't use IN unless it is dies in this insn,
2005 which means we must know accurately which hard regs are live.
2006 Also, the result can't go in IN if IN is used within OUT,
2007 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
2008 if (hard_regs_live_known
2009 && REG_P (in)
2010 && REGNO (in) < FIRST_PSEUDO_REGISTER
2011 && (value == 0
2012 || find_reg_note (this_insn, REG_UNUSED, real_out))
2013 && find_reg_note (this_insn, REG_DEAD, real_in)
2014 && !fixed_regs[REGNO (in)]
2015 && HARD_REGNO_MODE_OK (REGNO (in),
2016 /* The only case where out and real_out might
2017 have different modes is where real_out
2018 is a subreg, and in that case, out
2019 has a real mode. */
2020 (GET_MODE (out) != VOIDmode
2021 ? GET_MODE (out) : outmode))
2022 && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER
2023 /* However only do this if we can be sure that this input
2024 operand doesn't correspond with an uninitialized pseudo.
2025 global can assign some hardreg to it that is the same as
2026 the one assigned to a different, also live pseudo (as it
2027 can ignore the conflict). We must never introduce writes
2028 to such hardregs, as they would clobber the other live
2029 pseudo. See PR 20973. */
2030 || (!bitmap_bit_p (DF_LIVE_OUT (ENTRY_BLOCK_PTR),
2031 ORIGINAL_REGNO (in))
2032 /* Similarly, only do this if we can be sure that the death
2033 note is still valid. global can assign some hardreg to
2034 the pseudo referenced in the note and simultaneously a
2035 subword of this hardreg to a different, also live pseudo,
2036 because only another subword of the hardreg is actually
2037 used in the insn. This cannot happen if the pseudo has
2038 been assigned exactly one hardreg. See PR 33732. */
2039 && hard_regno_nregs[REGNO (in)][GET_MODE (in)] == 1)))
2041 unsigned int regno = REGNO (in) + in_offset;
2042 unsigned int nwords = hard_regno_nregs[regno][inmode];
2044 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, (rtx*) 0)
2045 && ! hard_reg_set_here_p (regno, regno + nwords,
2046 PATTERN (this_insn))
2047 && (! earlyclobber
2048 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
2049 PATTERN (this_insn), inloc)))
2051 unsigned int i;
2053 for (i = 0; i < nwords; i++)
2054 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2055 regno + i))
2056 break;
2058 if (i == nwords)
2060 /* If we were going to use OUT as the reload reg
2061 and changed our mind, it means OUT is a dummy that
2062 dies here. So don't bother copying value to it. */
2063 if (for_real >= 0 && value == real_out)
2064 rld[for_real].out = 0;
2065 if (REG_P (real_in))
2066 value = real_in;
2067 else
2068 value = gen_rtx_REG (inmode, regno);
2073 return value;
2076 /* This page contains subroutines used mainly for determining
2077 whether the IN or an OUT of a reload can serve as the
2078 reload register. */
2080 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
2083 earlyclobber_operand_p (rtx x)
2085 int i;
2087 for (i = 0; i < n_earlyclobbers; i++)
2088 if (reload_earlyclobbers[i] == x)
2089 return 1;
2091 return 0;
2094 /* Return 1 if expression X alters a hard reg in the range
2095 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
2096 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
2097 X should be the body of an instruction. */
2099 static int
2100 hard_reg_set_here_p (unsigned int beg_regno, unsigned int end_regno, rtx x)
2102 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
2104 rtx op0 = SET_DEST (x);
2106 while (GET_CODE (op0) == SUBREG)
2107 op0 = SUBREG_REG (op0);
2108 if (REG_P (op0))
2110 unsigned int r = REGNO (op0);
2112 /* See if this reg overlaps range under consideration. */
2113 if (r < end_regno
2114 && end_hard_regno (GET_MODE (op0), r) > beg_regno)
2115 return 1;
2118 else if (GET_CODE (x) == PARALLEL)
2120 int i = XVECLEN (x, 0) - 1;
2122 for (; i >= 0; i--)
2123 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
2124 return 1;
2127 return 0;
2130 /* Return 1 if ADDR is a valid memory address for mode MODE,
2131 and check that each pseudo reg has the proper kind of
2132 hard reg. */
2135 strict_memory_address_p (enum machine_mode mode ATTRIBUTE_UNUSED, rtx addr)
2137 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
2138 return 0;
2140 win:
2141 return 1;
2144 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
2145 if they are the same hard reg, and has special hacks for
2146 autoincrement and autodecrement.
2147 This is specifically intended for find_reloads to use
2148 in determining whether two operands match.
2149 X is the operand whose number is the lower of the two.
2151 The value is 2 if Y contains a pre-increment that matches
2152 a non-incrementing address in X. */
2154 /* ??? To be completely correct, we should arrange to pass
2155 for X the output operand and for Y the input operand.
2156 For now, we assume that the output operand has the lower number
2157 because that is natural in (SET output (... input ...)). */
2160 operands_match_p (rtx x, rtx y)
2162 int i;
2163 RTX_CODE code = GET_CODE (x);
2164 const char *fmt;
2165 int success_2;
2167 if (x == y)
2168 return 1;
2169 if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
2170 && (REG_P (y) || (GET_CODE (y) == SUBREG
2171 && REG_P (SUBREG_REG (y)))))
2173 int j;
2175 if (code == SUBREG)
2177 i = REGNO (SUBREG_REG (x));
2178 if (i >= FIRST_PSEUDO_REGISTER)
2179 goto slow;
2180 i += subreg_regno_offset (REGNO (SUBREG_REG (x)),
2181 GET_MODE (SUBREG_REG (x)),
2182 SUBREG_BYTE (x),
2183 GET_MODE (x));
2185 else
2186 i = REGNO (x);
2188 if (GET_CODE (y) == SUBREG)
2190 j = REGNO (SUBREG_REG (y));
2191 if (j >= FIRST_PSEUDO_REGISTER)
2192 goto slow;
2193 j += subreg_regno_offset (REGNO (SUBREG_REG (y)),
2194 GET_MODE (SUBREG_REG (y)),
2195 SUBREG_BYTE (y),
2196 GET_MODE (y));
2198 else
2199 j = REGNO (y);
2201 /* On a WORDS_BIG_ENDIAN machine, point to the last register of a
2202 multiple hard register group of scalar integer registers, so that
2203 for example (reg:DI 0) and (reg:SI 1) will be considered the same
2204 register. */
2205 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
2206 && SCALAR_INT_MODE_P (GET_MODE (x))
2207 && i < FIRST_PSEUDO_REGISTER)
2208 i += hard_regno_nregs[i][GET_MODE (x)] - 1;
2209 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (y)) > UNITS_PER_WORD
2210 && SCALAR_INT_MODE_P (GET_MODE (y))
2211 && j < FIRST_PSEUDO_REGISTER)
2212 j += hard_regno_nregs[j][GET_MODE (y)] - 1;
2214 return i == j;
2216 /* If two operands must match, because they are really a single
2217 operand of an assembler insn, then two postincrements are invalid
2218 because the assembler insn would increment only once.
2219 On the other hand, a postincrement matches ordinary indexing
2220 if the postincrement is the output operand. */
2221 if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
2222 return operands_match_p (XEXP (x, 0), y);
2223 /* Two preincrements are invalid
2224 because the assembler insn would increment only once.
2225 On the other hand, a preincrement matches ordinary indexing
2226 if the preincrement is the input operand.
2227 In this case, return 2, since some callers need to do special
2228 things when this happens. */
2229 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
2230 || GET_CODE (y) == PRE_MODIFY)
2231 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2233 slow:
2235 /* Now we have disposed of all the cases in which different rtx codes
2236 can match. */
2237 if (code != GET_CODE (y))
2238 return 0;
2240 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2241 if (GET_MODE (x) != GET_MODE (y))
2242 return 0;
2244 switch (code)
2246 case CONST_INT:
2247 case CONST_DOUBLE:
2248 case CONST_FIXED:
2249 return 0;
2251 case LABEL_REF:
2252 return XEXP (x, 0) == XEXP (y, 0);
2253 case SYMBOL_REF:
2254 return XSTR (x, 0) == XSTR (y, 0);
2256 default:
2257 break;
2260 /* Compare the elements. If any pair of corresponding elements
2261 fail to match, return 0 for the whole things. */
2263 success_2 = 0;
2264 fmt = GET_RTX_FORMAT (code);
2265 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2267 int val, j;
2268 switch (fmt[i])
2270 case 'w':
2271 if (XWINT (x, i) != XWINT (y, i))
2272 return 0;
2273 break;
2275 case 'i':
2276 if (XINT (x, i) != XINT (y, i))
2277 return 0;
2278 break;
2280 case 'e':
2281 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2282 if (val == 0)
2283 return 0;
2284 /* If any subexpression returns 2,
2285 we should return 2 if we are successful. */
2286 if (val == 2)
2287 success_2 = 1;
2288 break;
2290 case '0':
2291 break;
2293 case 'E':
2294 if (XVECLEN (x, i) != XVECLEN (y, i))
2295 return 0;
2296 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2298 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2299 if (val == 0)
2300 return 0;
2301 if (val == 2)
2302 success_2 = 1;
2304 break;
2306 /* It is believed that rtx's at this level will never
2307 contain anything but integers and other rtx's,
2308 except for within LABEL_REFs and SYMBOL_REFs. */
2309 default:
2310 gcc_unreachable ();
2313 return 1 + success_2;
2316 /* Describe the range of registers or memory referenced by X.
2317 If X is a register, set REG_FLAG and put the first register
2318 number into START and the last plus one into END.
2319 If X is a memory reference, put a base address into BASE
2320 and a range of integer offsets into START and END.
2321 If X is pushing on the stack, we can assume it causes no trouble,
2322 so we set the SAFE field. */
2324 static struct decomposition
2325 decompose (rtx x)
2327 struct decomposition val;
2328 int all_const = 0;
2330 memset (&val, 0, sizeof (val));
2332 switch (GET_CODE (x))
2334 case MEM:
2336 rtx base = NULL_RTX, offset = 0;
2337 rtx addr = XEXP (x, 0);
2339 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2340 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2342 val.base = XEXP (addr, 0);
2343 val.start = -GET_MODE_SIZE (GET_MODE (x));
2344 val.end = GET_MODE_SIZE (GET_MODE (x));
2345 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2346 return val;
2349 if (GET_CODE (addr) == PRE_MODIFY || GET_CODE (addr) == POST_MODIFY)
2351 if (GET_CODE (XEXP (addr, 1)) == PLUS
2352 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
2353 && CONSTANT_P (XEXP (XEXP (addr, 1), 1)))
2355 val.base = XEXP (addr, 0);
2356 val.start = -INTVAL (XEXP (XEXP (addr, 1), 1));
2357 val.end = INTVAL (XEXP (XEXP (addr, 1), 1));
2358 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2359 return val;
2363 if (GET_CODE (addr) == CONST)
2365 addr = XEXP (addr, 0);
2366 all_const = 1;
2368 if (GET_CODE (addr) == PLUS)
2370 if (CONSTANT_P (XEXP (addr, 0)))
2372 base = XEXP (addr, 1);
2373 offset = XEXP (addr, 0);
2375 else if (CONSTANT_P (XEXP (addr, 1)))
2377 base = XEXP (addr, 0);
2378 offset = XEXP (addr, 1);
2382 if (offset == 0)
2384 base = addr;
2385 offset = const0_rtx;
2387 if (GET_CODE (offset) == CONST)
2388 offset = XEXP (offset, 0);
2389 if (GET_CODE (offset) == PLUS)
2391 if (GET_CODE (XEXP (offset, 0)) == CONST_INT)
2393 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2394 offset = XEXP (offset, 0);
2396 else if (GET_CODE (XEXP (offset, 1)) == CONST_INT)
2398 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2399 offset = XEXP (offset, 1);
2401 else
2403 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2404 offset = const0_rtx;
2407 else if (GET_CODE (offset) != CONST_INT)
2409 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2410 offset = const0_rtx;
2413 if (all_const && GET_CODE (base) == PLUS)
2414 base = gen_rtx_CONST (GET_MODE (base), base);
2416 gcc_assert (GET_CODE (offset) == CONST_INT);
2418 val.start = INTVAL (offset);
2419 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2420 val.base = base;
2422 break;
2424 case REG:
2425 val.reg_flag = 1;
2426 val.start = true_regnum (x);
2427 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2429 /* A pseudo with no hard reg. */
2430 val.start = REGNO (x);
2431 val.end = val.start + 1;
2433 else
2434 /* A hard reg. */
2435 val.end = end_hard_regno (GET_MODE (x), val.start);
2436 break;
2438 case SUBREG:
2439 if (!REG_P (SUBREG_REG (x)))
2440 /* This could be more precise, but it's good enough. */
2441 return decompose (SUBREG_REG (x));
2442 val.reg_flag = 1;
2443 val.start = true_regnum (x);
2444 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2445 return decompose (SUBREG_REG (x));
2446 else
2447 /* A hard reg. */
2448 val.end = val.start + subreg_nregs (x);
2449 break;
2451 case SCRATCH:
2452 /* This hasn't been assigned yet, so it can't conflict yet. */
2453 val.safe = 1;
2454 break;
2456 default:
2457 gcc_assert (CONSTANT_P (x));
2458 val.safe = 1;
2459 break;
2461 return val;
2464 /* Return 1 if altering Y will not modify the value of X.
2465 Y is also described by YDATA, which should be decompose (Y). */
2467 static int
2468 immune_p (rtx x, rtx y, struct decomposition ydata)
2470 struct decomposition xdata;
2472 if (ydata.reg_flag)
2473 return !refers_to_regno_for_reload_p (ydata.start, ydata.end, x, (rtx*) 0);
2474 if (ydata.safe)
2475 return 1;
2477 gcc_assert (MEM_P (y));
2478 /* If Y is memory and X is not, Y can't affect X. */
2479 if (!MEM_P (x))
2480 return 1;
2482 xdata = decompose (x);
2484 if (! rtx_equal_p (xdata.base, ydata.base))
2486 /* If bases are distinct symbolic constants, there is no overlap. */
2487 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2488 return 1;
2489 /* Constants and stack slots never overlap. */
2490 if (CONSTANT_P (xdata.base)
2491 && (ydata.base == frame_pointer_rtx
2492 || ydata.base == hard_frame_pointer_rtx
2493 || ydata.base == stack_pointer_rtx))
2494 return 1;
2495 if (CONSTANT_P (ydata.base)
2496 && (xdata.base == frame_pointer_rtx
2497 || xdata.base == hard_frame_pointer_rtx
2498 || xdata.base == stack_pointer_rtx))
2499 return 1;
2500 /* If either base is variable, we don't know anything. */
2501 return 0;
2504 return (xdata.start >= ydata.end || ydata.start >= xdata.end);
2507 /* Similar, but calls decompose. */
2510 safe_from_earlyclobber (rtx op, rtx clobber)
2512 struct decomposition early_data;
2514 early_data = decompose (clobber);
2515 return immune_p (op, clobber, early_data);
2518 /* Main entry point of this file: search the body of INSN
2519 for values that need reloading and record them with push_reload.
2520 REPLACE nonzero means record also where the values occur
2521 so that subst_reloads can be used.
2523 IND_LEVELS says how many levels of indirection are supported by this
2524 machine; a value of zero means that a memory reference is not a valid
2525 memory address.
2527 LIVE_KNOWN says we have valid information about which hard
2528 regs are live at each point in the program; this is true when
2529 we are called from global_alloc but false when stupid register
2530 allocation has been done.
2532 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2533 which is nonnegative if the reg has been commandeered for reloading into.
2534 It is copied into STATIC_RELOAD_REG_P and referenced from there
2535 by various subroutines.
2537 Return TRUE if some operands need to be changed, because of swapping
2538 commutative operands, reg_equiv_address substitution, or whatever. */
2541 find_reloads (rtx insn, int replace, int ind_levels, int live_known,
2542 short *reload_reg_p)
2544 int insn_code_number;
2545 int i, j;
2546 int noperands;
2547 /* These start out as the constraints for the insn
2548 and they are chewed up as we consider alternatives. */
2549 const char *constraints[MAX_RECOG_OPERANDS];
2550 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2551 a register. */
2552 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2553 char pref_or_nothing[MAX_RECOG_OPERANDS];
2554 /* Nonzero for a MEM operand whose entire address needs a reload.
2555 May be -1 to indicate the entire address may or may not need a reload. */
2556 int address_reloaded[MAX_RECOG_OPERANDS];
2557 /* Nonzero for an address operand that needs to be completely reloaded.
2558 May be -1 to indicate the entire operand may or may not need a reload. */
2559 int address_operand_reloaded[MAX_RECOG_OPERANDS];
2560 /* Value of enum reload_type to use for operand. */
2561 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2562 /* Value of enum reload_type to use within address of operand. */
2563 enum reload_type address_type[MAX_RECOG_OPERANDS];
2564 /* Save the usage of each operand. */
2565 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2566 int no_input_reloads = 0, no_output_reloads = 0;
2567 int n_alternatives;
2568 int this_alternative[MAX_RECOG_OPERANDS];
2569 char this_alternative_match_win[MAX_RECOG_OPERANDS];
2570 char this_alternative_win[MAX_RECOG_OPERANDS];
2571 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2572 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2573 int this_alternative_matches[MAX_RECOG_OPERANDS];
2574 int swapped;
2575 int goal_alternative[MAX_RECOG_OPERANDS];
2576 int this_alternative_number;
2577 int goal_alternative_number = 0;
2578 int operand_reloadnum[MAX_RECOG_OPERANDS];
2579 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2580 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2581 char goal_alternative_match_win[MAX_RECOG_OPERANDS];
2582 char goal_alternative_win[MAX_RECOG_OPERANDS];
2583 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2584 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2585 int goal_alternative_swapped;
2586 int best;
2587 int commutative;
2588 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2589 rtx substed_operand[MAX_RECOG_OPERANDS];
2590 rtx body = PATTERN (insn);
2591 rtx set = single_set (insn);
2592 int goal_earlyclobber = 0, this_earlyclobber;
2593 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
2594 int retval = 0;
2596 this_insn = insn;
2597 n_reloads = 0;
2598 n_replacements = 0;
2599 n_earlyclobbers = 0;
2600 replace_reloads = replace;
2601 hard_regs_live_known = live_known;
2602 static_reload_reg_p = reload_reg_p;
2604 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads;
2605 neither are insns that SET cc0. Insns that use CC0 are not allowed
2606 to have any input reloads. */
2607 if (JUMP_P (insn) || CALL_P (insn))
2608 no_output_reloads = 1;
2610 #ifdef HAVE_cc0
2611 if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
2612 no_input_reloads = 1;
2613 if (reg_set_p (cc0_rtx, PATTERN (insn)))
2614 no_output_reloads = 1;
2615 #endif
2617 #ifdef SECONDARY_MEMORY_NEEDED
2618 /* The eliminated forms of any secondary memory locations are per-insn, so
2619 clear them out here. */
2621 if (secondary_memlocs_elim_used)
2623 memset (secondary_memlocs_elim, 0,
2624 sizeof (secondary_memlocs_elim[0]) * secondary_memlocs_elim_used);
2625 secondary_memlocs_elim_used = 0;
2627 #endif
2629 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2630 is cheap to move between them. If it is not, there may not be an insn
2631 to do the copy, so we may need a reload. */
2632 if (GET_CODE (body) == SET
2633 && REG_P (SET_DEST (body))
2634 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2635 && REG_P (SET_SRC (body))
2636 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2637 && REGISTER_MOVE_COST (GET_MODE (SET_SRC (body)),
2638 REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2639 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2640 return 0;
2642 extract_insn (insn);
2644 noperands = reload_n_operands = recog_data.n_operands;
2645 n_alternatives = recog_data.n_alternatives;
2647 /* Just return "no reloads" if insn has no operands with constraints. */
2648 if (noperands == 0 || n_alternatives == 0)
2649 return 0;
2651 insn_code_number = INSN_CODE (insn);
2652 this_insn_is_asm = insn_code_number < 0;
2654 memcpy (operand_mode, recog_data.operand_mode,
2655 noperands * sizeof (enum machine_mode));
2656 memcpy (constraints, recog_data.constraints,
2657 noperands * sizeof (const char *));
2659 commutative = -1;
2661 /* If we will need to know, later, whether some pair of operands
2662 are the same, we must compare them now and save the result.
2663 Reloading the base and index registers will clobber them
2664 and afterward they will fail to match. */
2666 for (i = 0; i < noperands; i++)
2668 const char *p;
2669 int c;
2670 char *end;
2672 substed_operand[i] = recog_data.operand[i];
2673 p = constraints[i];
2675 modified[i] = RELOAD_READ;
2677 /* Scan this operand's constraint to see if it is an output operand,
2678 an in-out operand, is commutative, or should match another. */
2680 while ((c = *p))
2682 p += CONSTRAINT_LEN (c, p);
2683 switch (c)
2685 case '=':
2686 modified[i] = RELOAD_WRITE;
2687 break;
2688 case '+':
2689 modified[i] = RELOAD_READ_WRITE;
2690 break;
2691 case '%':
2693 /* The last operand should not be marked commutative. */
2694 gcc_assert (i != noperands - 1);
2696 /* We currently only support one commutative pair of
2697 operands. Some existing asm code currently uses more
2698 than one pair. Previously, that would usually work,
2699 but sometimes it would crash the compiler. We
2700 continue supporting that case as well as we can by
2701 silently ignoring all but the first pair. In the
2702 future we may handle it correctly. */
2703 if (commutative < 0)
2704 commutative = i;
2705 else
2706 gcc_assert (this_insn_is_asm);
2708 break;
2709 /* Use of ISDIGIT is tempting here, but it may get expensive because
2710 of locale support we don't want. */
2711 case '0': case '1': case '2': case '3': case '4':
2712 case '5': case '6': case '7': case '8': case '9':
2714 c = strtoul (p - 1, &end, 10);
2715 p = end;
2717 operands_match[c][i]
2718 = operands_match_p (recog_data.operand[c],
2719 recog_data.operand[i]);
2721 /* An operand may not match itself. */
2722 gcc_assert (c != i);
2724 /* If C can be commuted with C+1, and C might need to match I,
2725 then C+1 might also need to match I. */
2726 if (commutative >= 0)
2728 if (c == commutative || c == commutative + 1)
2730 int other = c + (c == commutative ? 1 : -1);
2731 operands_match[other][i]
2732 = operands_match_p (recog_data.operand[other],
2733 recog_data.operand[i]);
2735 if (i == commutative || i == commutative + 1)
2737 int other = i + (i == commutative ? 1 : -1);
2738 operands_match[c][other]
2739 = operands_match_p (recog_data.operand[c],
2740 recog_data.operand[other]);
2742 /* Note that C is supposed to be less than I.
2743 No need to consider altering both C and I because in
2744 that case we would alter one into the other. */
2751 /* Examine each operand that is a memory reference or memory address
2752 and reload parts of the addresses into index registers.
2753 Also here any references to pseudo regs that didn't get hard regs
2754 but are equivalent to constants get replaced in the insn itself
2755 with those constants. Nobody will ever see them again.
2757 Finally, set up the preferred classes of each operand. */
2759 for (i = 0; i < noperands; i++)
2761 RTX_CODE code = GET_CODE (recog_data.operand[i]);
2763 address_reloaded[i] = 0;
2764 address_operand_reloaded[i] = 0;
2765 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2766 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2767 : RELOAD_OTHER);
2768 address_type[i]
2769 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2770 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2771 : RELOAD_OTHER);
2773 if (*constraints[i] == 0)
2774 /* Ignore things like match_operator operands. */
2776 else if (constraints[i][0] == 'p'
2777 || EXTRA_ADDRESS_CONSTRAINT (constraints[i][0], constraints[i]))
2779 address_operand_reloaded[i]
2780 = find_reloads_address (recog_data.operand_mode[i], (rtx*) 0,
2781 recog_data.operand[i],
2782 recog_data.operand_loc[i],
2783 i, operand_type[i], ind_levels, insn);
2785 /* If we now have a simple operand where we used to have a
2786 PLUS or MULT, re-recognize and try again. */
2787 if ((OBJECT_P (*recog_data.operand_loc[i])
2788 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2789 && (GET_CODE (recog_data.operand[i]) == MULT
2790 || GET_CODE (recog_data.operand[i]) == PLUS))
2792 INSN_CODE (insn) = -1;
2793 retval = find_reloads (insn, replace, ind_levels, live_known,
2794 reload_reg_p);
2795 return retval;
2798 recog_data.operand[i] = *recog_data.operand_loc[i];
2799 substed_operand[i] = recog_data.operand[i];
2801 /* Address operands are reloaded in their existing mode,
2802 no matter what is specified in the machine description. */
2803 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2805 else if (code == MEM)
2807 address_reloaded[i]
2808 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2809 recog_data.operand_loc[i],
2810 XEXP (recog_data.operand[i], 0),
2811 &XEXP (recog_data.operand[i], 0),
2812 i, address_type[i], ind_levels, insn);
2813 recog_data.operand[i] = *recog_data.operand_loc[i];
2814 substed_operand[i] = recog_data.operand[i];
2816 else if (code == SUBREG)
2818 rtx reg = SUBREG_REG (recog_data.operand[i]);
2819 rtx op
2820 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2821 ind_levels,
2822 set != 0
2823 && &SET_DEST (set) == recog_data.operand_loc[i],
2824 insn,
2825 &address_reloaded[i]);
2827 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2828 that didn't get a hard register, emit a USE with a REG_EQUAL
2829 note in front so that we might inherit a previous, possibly
2830 wider reload. */
2832 if (replace
2833 && MEM_P (op)
2834 && REG_P (reg)
2835 && (GET_MODE_SIZE (GET_MODE (reg))
2836 >= GET_MODE_SIZE (GET_MODE (op)))
2837 && reg_equiv_constant[REGNO (reg)] == 0)
2838 set_unique_reg_note (emit_insn_before (gen_rtx_USE (VOIDmode, reg),
2839 insn),
2840 REG_EQUAL, reg_equiv_memory_loc[REGNO (reg)]);
2842 substed_operand[i] = recog_data.operand[i] = op;
2844 else if (code == PLUS || GET_RTX_CLASS (code) == RTX_UNARY)
2845 /* We can get a PLUS as an "operand" as a result of register
2846 elimination. See eliminate_regs and gen_reload. We handle
2847 a unary operator by reloading the operand. */
2848 substed_operand[i] = recog_data.operand[i]
2849 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2850 ind_levels, 0, insn,
2851 &address_reloaded[i]);
2852 else if (code == REG)
2854 /* This is equivalent to calling find_reloads_toplev.
2855 The code is duplicated for speed.
2856 When we find a pseudo always equivalent to a constant,
2857 we replace it by the constant. We must be sure, however,
2858 that we don't try to replace it in the insn in which it
2859 is being set. */
2860 int regno = REGNO (recog_data.operand[i]);
2861 if (reg_equiv_constant[regno] != 0
2862 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2864 /* Record the existing mode so that the check if constants are
2865 allowed will work when operand_mode isn't specified. */
2867 if (operand_mode[i] == VOIDmode)
2868 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2870 substed_operand[i] = recog_data.operand[i]
2871 = reg_equiv_constant[regno];
2873 if (reg_equiv_memory_loc[regno] != 0
2874 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
2875 /* We need not give a valid is_set_dest argument since the case
2876 of a constant equivalence was checked above. */
2877 substed_operand[i] = recog_data.operand[i]
2878 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2879 ind_levels, 0, insn,
2880 &address_reloaded[i]);
2882 /* If the operand is still a register (we didn't replace it with an
2883 equivalent), get the preferred class to reload it into. */
2884 code = GET_CODE (recog_data.operand[i]);
2885 preferred_class[i]
2886 = ((code == REG && REGNO (recog_data.operand[i])
2887 >= FIRST_PSEUDO_REGISTER)
2888 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2889 : NO_REGS);
2890 pref_or_nothing[i]
2891 = (code == REG
2892 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2893 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2896 /* If this is simply a copy from operand 1 to operand 0, merge the
2897 preferred classes for the operands. */
2898 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2899 && recog_data.operand[1] == SET_SRC (set))
2901 preferred_class[0] = preferred_class[1]
2902 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2903 pref_or_nothing[0] |= pref_or_nothing[1];
2904 pref_or_nothing[1] |= pref_or_nothing[0];
2907 /* Now see what we need for pseudo-regs that didn't get hard regs
2908 or got the wrong kind of hard reg. For this, we must consider
2909 all the operands together against the register constraints. */
2911 best = MAX_RECOG_OPERANDS * 2 + 600;
2913 swapped = 0;
2914 goal_alternative_swapped = 0;
2915 try_swapped:
2917 /* The constraints are made of several alternatives.
2918 Each operand's constraint looks like foo,bar,... with commas
2919 separating the alternatives. The first alternatives for all
2920 operands go together, the second alternatives go together, etc.
2922 First loop over alternatives. */
2924 for (this_alternative_number = 0;
2925 this_alternative_number < n_alternatives;
2926 this_alternative_number++)
2928 /* Loop over operands for one constraint alternative. */
2929 /* LOSERS counts those that don't fit this alternative
2930 and would require loading. */
2931 int losers = 0;
2932 /* BAD is set to 1 if it some operand can't fit this alternative
2933 even after reloading. */
2934 int bad = 0;
2935 /* REJECT is a count of how undesirable this alternative says it is
2936 if any reloading is required. If the alternative matches exactly
2937 then REJECT is ignored, but otherwise it gets this much
2938 counted against it in addition to the reloading needed. Each
2939 ? counts three times here since we want the disparaging caused by
2940 a bad register class to only count 1/3 as much. */
2941 int reject = 0;
2943 if (!recog_data.alternative_enabled_p[this_alternative_number])
2945 int i;
2947 for (i = 0; i < recog_data.n_operands; i++)
2948 constraints[i] = skip_alternative (constraints[i]);
2950 continue;
2953 this_earlyclobber = 0;
2955 for (i = 0; i < noperands; i++)
2957 const char *p = constraints[i];
2958 char *end;
2959 int len;
2960 int win = 0;
2961 int did_match = 0;
2962 /* 0 => this operand can be reloaded somehow for this alternative. */
2963 int badop = 1;
2964 /* 0 => this operand can be reloaded if the alternative allows regs. */
2965 int winreg = 0;
2966 int c;
2967 int m;
2968 rtx operand = recog_data.operand[i];
2969 int offset = 0;
2970 /* Nonzero means this is a MEM that must be reloaded into a reg
2971 regardless of what the constraint says. */
2972 int force_reload = 0;
2973 int offmemok = 0;
2974 /* Nonzero if a constant forced into memory would be OK for this
2975 operand. */
2976 int constmemok = 0;
2977 int earlyclobber = 0;
2979 /* If the predicate accepts a unary operator, it means that
2980 we need to reload the operand, but do not do this for
2981 match_operator and friends. */
2982 if (UNARY_P (operand) && *p != 0)
2983 operand = XEXP (operand, 0);
2985 /* If the operand is a SUBREG, extract
2986 the REG or MEM (or maybe even a constant) within.
2987 (Constants can occur as a result of reg_equiv_constant.) */
2989 while (GET_CODE (operand) == SUBREG)
2991 /* Offset only matters when operand is a REG and
2992 it is a hard reg. This is because it is passed
2993 to reg_fits_class_p if it is a REG and all pseudos
2994 return 0 from that function. */
2995 if (REG_P (SUBREG_REG (operand))
2996 && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
2998 if (!subreg_offset_representable_p
2999 (REGNO (SUBREG_REG (operand)),
3000 GET_MODE (SUBREG_REG (operand)),
3001 SUBREG_BYTE (operand),
3002 GET_MODE (operand)))
3003 force_reload = 1;
3004 offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
3005 GET_MODE (SUBREG_REG (operand)),
3006 SUBREG_BYTE (operand),
3007 GET_MODE (operand));
3009 operand = SUBREG_REG (operand);
3010 /* Force reload if this is a constant or PLUS or if there may
3011 be a problem accessing OPERAND in the outer mode. */
3012 if (CONSTANT_P (operand)
3013 || GET_CODE (operand) == PLUS
3014 /* We must force a reload of paradoxical SUBREGs
3015 of a MEM because the alignment of the inner value
3016 may not be enough to do the outer reference. On
3017 big-endian machines, it may also reference outside
3018 the object.
3020 On machines that extend byte operations and we have a
3021 SUBREG where both the inner and outer modes are no wider
3022 than a word and the inner mode is narrower, is integral,
3023 and gets extended when loaded from memory, combine.c has
3024 made assumptions about the behavior of the machine in such
3025 register access. If the data is, in fact, in memory we
3026 must always load using the size assumed to be in the
3027 register and let the insn do the different-sized
3028 accesses.
3030 This is doubly true if WORD_REGISTER_OPERATIONS. In
3031 this case eliminate_regs has left non-paradoxical
3032 subregs for push_reload to see. Make sure it does
3033 by forcing the reload.
3035 ??? When is it right at this stage to have a subreg
3036 of a mem that is _not_ to be handled specially? IMO
3037 those should have been reduced to just a mem. */
3038 || ((MEM_P (operand)
3039 || (REG_P (operand)
3040 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3041 #ifndef WORD_REGISTER_OPERATIONS
3042 && (((GET_MODE_BITSIZE (GET_MODE (operand))
3043 < BIGGEST_ALIGNMENT)
3044 && (GET_MODE_SIZE (operand_mode[i])
3045 > GET_MODE_SIZE (GET_MODE (operand))))
3046 || BYTES_BIG_ENDIAN
3047 #ifdef LOAD_EXTEND_OP
3048 || (GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3049 && (GET_MODE_SIZE (GET_MODE (operand))
3050 <= UNITS_PER_WORD)
3051 && (GET_MODE_SIZE (operand_mode[i])
3052 > GET_MODE_SIZE (GET_MODE (operand)))
3053 && INTEGRAL_MODE_P (GET_MODE (operand))
3054 && LOAD_EXTEND_OP (GET_MODE (operand)) != UNKNOWN)
3055 #endif
3057 #endif
3060 force_reload = 1;
3063 this_alternative[i] = (int) NO_REGS;
3064 this_alternative_win[i] = 0;
3065 this_alternative_match_win[i] = 0;
3066 this_alternative_offmemok[i] = 0;
3067 this_alternative_earlyclobber[i] = 0;
3068 this_alternative_matches[i] = -1;
3070 /* An empty constraint or empty alternative
3071 allows anything which matched the pattern. */
3072 if (*p == 0 || *p == ',')
3073 win = 1, badop = 0;
3075 /* Scan this alternative's specs for this operand;
3076 set WIN if the operand fits any letter in this alternative.
3077 Otherwise, clear BADOP if this operand could
3078 fit some letter after reloads,
3079 or set WINREG if this operand could fit after reloads
3080 provided the constraint allows some registers. */
3083 switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
3085 case '\0':
3086 len = 0;
3087 break;
3088 case ',':
3089 c = '\0';
3090 break;
3092 case '=': case '+': case '*':
3093 break;
3095 case '%':
3096 /* We only support one commutative marker, the first
3097 one. We already set commutative above. */
3098 break;
3100 case '?':
3101 reject += 6;
3102 break;
3104 case '!':
3105 reject = 600;
3106 break;
3108 case '#':
3109 /* Ignore rest of this alternative as far as
3110 reloading is concerned. */
3112 p++;
3113 while (*p && *p != ',');
3114 len = 0;
3115 break;
3117 case '0': case '1': case '2': case '3': case '4':
3118 case '5': case '6': case '7': case '8': case '9':
3119 m = strtoul (p, &end, 10);
3120 p = end;
3121 len = 0;
3123 this_alternative_matches[i] = m;
3124 /* We are supposed to match a previous operand.
3125 If we do, we win if that one did.
3126 If we do not, count both of the operands as losers.
3127 (This is too conservative, since most of the time
3128 only a single reload insn will be needed to make
3129 the two operands win. As a result, this alternative
3130 may be rejected when it is actually desirable.) */
3131 if ((swapped && (m != commutative || i != commutative + 1))
3132 /* If we are matching as if two operands were swapped,
3133 also pretend that operands_match had been computed
3134 with swapped.
3135 But if I is the second of those and C is the first,
3136 don't exchange them, because operands_match is valid
3137 only on one side of its diagonal. */
3138 ? (operands_match
3139 [(m == commutative || m == commutative + 1)
3140 ? 2 * commutative + 1 - m : m]
3141 [(i == commutative || i == commutative + 1)
3142 ? 2 * commutative + 1 - i : i])
3143 : operands_match[m][i])
3145 /* If we are matching a non-offsettable address where an
3146 offsettable address was expected, then we must reject
3147 this combination, because we can't reload it. */
3148 if (this_alternative_offmemok[m]
3149 && MEM_P (recog_data.operand[m])
3150 && this_alternative[m] == (int) NO_REGS
3151 && ! this_alternative_win[m])
3152 bad = 1;
3154 did_match = this_alternative_win[m];
3156 else
3158 /* Operands don't match. */
3159 rtx value;
3160 int loc1, loc2;
3161 /* Retroactively mark the operand we had to match
3162 as a loser, if it wasn't already. */
3163 if (this_alternative_win[m])
3164 losers++;
3165 this_alternative_win[m] = 0;
3166 if (this_alternative[m] == (int) NO_REGS)
3167 bad = 1;
3168 /* But count the pair only once in the total badness of
3169 this alternative, if the pair can be a dummy reload.
3170 The pointers in operand_loc are not swapped; swap
3171 them by hand if necessary. */
3172 if (swapped && i == commutative)
3173 loc1 = commutative + 1;
3174 else if (swapped && i == commutative + 1)
3175 loc1 = commutative;
3176 else
3177 loc1 = i;
3178 if (swapped && m == commutative)
3179 loc2 = commutative + 1;
3180 else if (swapped && m == commutative + 1)
3181 loc2 = commutative;
3182 else
3183 loc2 = m;
3184 value
3185 = find_dummy_reload (recog_data.operand[i],
3186 recog_data.operand[m],
3187 recog_data.operand_loc[loc1],
3188 recog_data.operand_loc[loc2],
3189 operand_mode[i], operand_mode[m],
3190 this_alternative[m], -1,
3191 this_alternative_earlyclobber[m]);
3193 if (value != 0)
3194 losers--;
3196 /* This can be fixed with reloads if the operand
3197 we are supposed to match can be fixed with reloads. */
3198 badop = 0;
3199 this_alternative[i] = this_alternative[m];
3201 /* If we have to reload this operand and some previous
3202 operand also had to match the same thing as this
3203 operand, we don't know how to do that. So reject this
3204 alternative. */
3205 if (! did_match || force_reload)
3206 for (j = 0; j < i; j++)
3207 if (this_alternative_matches[j]
3208 == this_alternative_matches[i])
3209 badop = 1;
3210 break;
3212 case 'p':
3213 /* All necessary reloads for an address_operand
3214 were handled in find_reloads_address. */
3215 this_alternative[i]
3216 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3217 win = 1;
3218 badop = 0;
3219 break;
3221 case TARGET_MEM_CONSTRAINT:
3222 if (force_reload)
3223 break;
3224 if (MEM_P (operand)
3225 || (REG_P (operand)
3226 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3227 && reg_renumber[REGNO (operand)] < 0))
3228 win = 1;
3229 if (CONST_POOL_OK_P (operand))
3230 badop = 0;
3231 constmemok = 1;
3232 break;
3234 case '<':
3235 if (MEM_P (operand)
3236 && ! address_reloaded[i]
3237 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
3238 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
3239 win = 1;
3240 break;
3242 case '>':
3243 if (MEM_P (operand)
3244 && ! address_reloaded[i]
3245 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
3246 || GET_CODE (XEXP (operand, 0)) == POST_INC))
3247 win = 1;
3248 break;
3250 /* Memory operand whose address is not offsettable. */
3251 case 'V':
3252 if (force_reload)
3253 break;
3254 if (MEM_P (operand)
3255 && ! (ind_levels ? offsettable_memref_p (operand)
3256 : offsettable_nonstrict_memref_p (operand))
3257 /* Certain mem addresses will become offsettable
3258 after they themselves are reloaded. This is important;
3259 we don't want our own handling of unoffsettables
3260 to override the handling of reg_equiv_address. */
3261 && !(REG_P (XEXP (operand, 0))
3262 && (ind_levels == 0
3263 || reg_equiv_address[REGNO (XEXP (operand, 0))] != 0)))
3264 win = 1;
3265 break;
3267 /* Memory operand whose address is offsettable. */
3268 case 'o':
3269 if (force_reload)
3270 break;
3271 if ((MEM_P (operand)
3272 /* If IND_LEVELS, find_reloads_address won't reload a
3273 pseudo that didn't get a hard reg, so we have to
3274 reject that case. */
3275 && ((ind_levels ? offsettable_memref_p (operand)
3276 : offsettable_nonstrict_memref_p (operand))
3277 /* A reloaded address is offsettable because it is now
3278 just a simple register indirect. */
3279 || address_reloaded[i] == 1))
3280 || (REG_P (operand)
3281 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3282 && reg_renumber[REGNO (operand)] < 0
3283 /* If reg_equiv_address is nonzero, we will be
3284 loading it into a register; hence it will be
3285 offsettable, but we cannot say that reg_equiv_mem
3286 is offsettable without checking. */
3287 && ((reg_equiv_mem[REGNO (operand)] != 0
3288 && offsettable_memref_p (reg_equiv_mem[REGNO (operand)]))
3289 || (reg_equiv_address[REGNO (operand)] != 0))))
3290 win = 1;
3291 if (CONST_POOL_OK_P (operand)
3292 || MEM_P (operand))
3293 badop = 0;
3294 constmemok = 1;
3295 offmemok = 1;
3296 break;
3298 case '&':
3299 /* Output operand that is stored before the need for the
3300 input operands (and their index registers) is over. */
3301 earlyclobber = 1, this_earlyclobber = 1;
3302 break;
3304 case 'E':
3305 case 'F':
3306 if (GET_CODE (operand) == CONST_DOUBLE
3307 || (GET_CODE (operand) == CONST_VECTOR
3308 && (GET_MODE_CLASS (GET_MODE (operand))
3309 == MODE_VECTOR_FLOAT)))
3310 win = 1;
3311 break;
3313 case 'G':
3314 case 'H':
3315 if (GET_CODE (operand) == CONST_DOUBLE
3316 && CONST_DOUBLE_OK_FOR_CONSTRAINT_P (operand, c, p))
3317 win = 1;
3318 break;
3320 case 's':
3321 if (GET_CODE (operand) == CONST_INT
3322 || (GET_CODE (operand) == CONST_DOUBLE
3323 && GET_MODE (operand) == VOIDmode))
3324 break;
3325 case 'i':
3326 if (CONSTANT_P (operand)
3327 && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (operand)))
3328 win = 1;
3329 break;
3331 case 'n':
3332 if (GET_CODE (operand) == CONST_INT
3333 || (GET_CODE (operand) == CONST_DOUBLE
3334 && GET_MODE (operand) == VOIDmode))
3335 win = 1;
3336 break;
3338 case 'I':
3339 case 'J':
3340 case 'K':
3341 case 'L':
3342 case 'M':
3343 case 'N':
3344 case 'O':
3345 case 'P':
3346 if (GET_CODE (operand) == CONST_INT
3347 && CONST_OK_FOR_CONSTRAINT_P (INTVAL (operand), c, p))
3348 win = 1;
3349 break;
3351 case 'X':
3352 force_reload = 0;
3353 win = 1;
3354 break;
3356 case 'g':
3357 if (! force_reload
3358 /* A PLUS is never a valid operand, but reload can make
3359 it from a register when eliminating registers. */
3360 && GET_CODE (operand) != PLUS
3361 /* A SCRATCH is not a valid operand. */
3362 && GET_CODE (operand) != SCRATCH
3363 && (! CONSTANT_P (operand)
3364 || ! flag_pic
3365 || LEGITIMATE_PIC_OPERAND_P (operand))
3366 && (GENERAL_REGS == ALL_REGS
3367 || !REG_P (operand)
3368 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3369 && reg_renumber[REGNO (operand)] < 0)))
3370 win = 1;
3371 /* Drop through into 'r' case. */
3373 case 'r':
3374 this_alternative[i]
3375 = (int) reg_class_subunion[this_alternative[i]][(int) GENERAL_REGS];
3376 goto reg;
3378 default:
3379 if (REG_CLASS_FROM_CONSTRAINT (c, p) == NO_REGS)
3381 #ifdef EXTRA_CONSTRAINT_STR
3382 if (EXTRA_MEMORY_CONSTRAINT (c, p))
3384 if (force_reload)
3385 break;
3386 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3387 win = 1;
3388 /* If the address was already reloaded,
3389 we win as well. */
3390 else if (MEM_P (operand)
3391 && address_reloaded[i] == 1)
3392 win = 1;
3393 /* Likewise if the address will be reloaded because
3394 reg_equiv_address is nonzero. For reg_equiv_mem
3395 we have to check. */
3396 else if (REG_P (operand)
3397 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3398 && reg_renumber[REGNO (operand)] < 0
3399 && ((reg_equiv_mem[REGNO (operand)] != 0
3400 && EXTRA_CONSTRAINT_STR (reg_equiv_mem[REGNO (operand)], c, p))
3401 || (reg_equiv_address[REGNO (operand)] != 0)))
3402 win = 1;
3404 /* If we didn't already win, we can reload
3405 constants via force_const_mem, and other
3406 MEMs by reloading the address like for 'o'. */
3407 if (CONST_POOL_OK_P (operand)
3408 || MEM_P (operand))
3409 badop = 0;
3410 constmemok = 1;
3411 offmemok = 1;
3412 break;
3414 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
3416 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3417 win = 1;
3419 /* If we didn't already win, we can reload
3420 the address into a base register. */
3421 this_alternative[i]
3422 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3423 badop = 0;
3424 break;
3427 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3428 win = 1;
3429 #endif
3430 break;
3433 this_alternative[i]
3434 = (int) (reg_class_subunion
3435 [this_alternative[i]]
3436 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)]);
3437 reg:
3438 if (GET_MODE (operand) == BLKmode)
3439 break;
3440 winreg = 1;
3441 if (REG_P (operand)
3442 && reg_fits_class_p (operand, this_alternative[i],
3443 offset, GET_MODE (recog_data.operand[i])))
3444 win = 1;
3445 break;
3447 while ((p += len), c);
3449 constraints[i] = p;
3451 /* If this operand could be handled with a reg,
3452 and some reg is allowed, then this operand can be handled. */
3453 if (winreg && this_alternative[i] != (int) NO_REGS)
3454 badop = 0;
3456 /* Record which operands fit this alternative. */
3457 this_alternative_earlyclobber[i] = earlyclobber;
3458 if (win && ! force_reload)
3459 this_alternative_win[i] = 1;
3460 else if (did_match && ! force_reload)
3461 this_alternative_match_win[i] = 1;
3462 else
3464 int const_to_mem = 0;
3466 this_alternative_offmemok[i] = offmemok;
3467 losers++;
3468 if (badop)
3469 bad = 1;
3470 /* Alternative loses if it has no regs for a reg operand. */
3471 if (REG_P (operand)
3472 && this_alternative[i] == (int) NO_REGS
3473 && this_alternative_matches[i] < 0)
3474 bad = 1;
3476 /* If this is a constant that is reloaded into the desired
3477 class by copying it to memory first, count that as another
3478 reload. This is consistent with other code and is
3479 required to avoid choosing another alternative when
3480 the constant is moved into memory by this function on
3481 an early reload pass. Note that the test here is
3482 precisely the same as in the code below that calls
3483 force_const_mem. */
3484 if (CONST_POOL_OK_P (operand)
3485 && ((PREFERRED_RELOAD_CLASS (operand,
3486 (enum reg_class) this_alternative[i])
3487 == NO_REGS)
3488 || no_input_reloads)
3489 && operand_mode[i] != VOIDmode)
3491 const_to_mem = 1;
3492 if (this_alternative[i] != (int) NO_REGS)
3493 losers++;
3496 /* Alternative loses if it requires a type of reload not
3497 permitted for this insn. We can always reload SCRATCH
3498 and objects with a REG_UNUSED note. */
3499 if (GET_CODE (operand) != SCRATCH
3500 && modified[i] != RELOAD_READ && no_output_reloads
3501 && ! find_reg_note (insn, REG_UNUSED, operand))
3502 bad = 1;
3503 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3504 && ! const_to_mem)
3505 bad = 1;
3507 /* If we can't reload this value at all, reject this
3508 alternative. Note that we could also lose due to
3509 LIMIT_RELOAD_CLASS, but we don't check that
3510 here. */
3512 if (! CONSTANT_P (operand)
3513 && (enum reg_class) this_alternative[i] != NO_REGS)
3515 if (PREFERRED_RELOAD_CLASS
3516 (operand, (enum reg_class) this_alternative[i])
3517 == NO_REGS)
3518 reject = 600;
3520 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
3521 if (operand_type[i] == RELOAD_FOR_OUTPUT
3522 && PREFERRED_OUTPUT_RELOAD_CLASS
3523 (operand, (enum reg_class) this_alternative[i])
3524 == NO_REGS)
3525 reject = 600;
3526 #endif
3529 /* We prefer to reload pseudos over reloading other things,
3530 since such reloads may be able to be eliminated later.
3531 If we are reloading a SCRATCH, we won't be generating any
3532 insns, just using a register, so it is also preferred.
3533 So bump REJECT in other cases. Don't do this in the
3534 case where we are forcing a constant into memory and
3535 it will then win since we don't want to have a different
3536 alternative match then. */
3537 if (! (REG_P (operand)
3538 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3539 && GET_CODE (operand) != SCRATCH
3540 && ! (const_to_mem && constmemok))
3541 reject += 2;
3543 /* Input reloads can be inherited more often than output
3544 reloads can be removed, so penalize output reloads. */
3545 if (operand_type[i] != RELOAD_FOR_INPUT
3546 && GET_CODE (operand) != SCRATCH)
3547 reject++;
3550 /* If this operand is a pseudo register that didn't get a hard
3551 reg and this alternative accepts some register, see if the
3552 class that we want is a subset of the preferred class for this
3553 register. If not, but it intersects that class, use the
3554 preferred class instead. If it does not intersect the preferred
3555 class, show that usage of this alternative should be discouraged;
3556 it will be discouraged more still if the register is `preferred
3557 or nothing'. We do this because it increases the chance of
3558 reusing our spill register in a later insn and avoiding a pair
3559 of memory stores and loads.
3561 Don't bother with this if this alternative will accept this
3562 operand.
3564 Don't do this for a multiword operand, since it is only a
3565 small win and has the risk of requiring more spill registers,
3566 which could cause a large loss.
3568 Don't do this if the preferred class has only one register
3569 because we might otherwise exhaust the class. */
3571 if (! win && ! did_match
3572 && this_alternative[i] != (int) NO_REGS
3573 && GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3574 && reg_class_size [(int) preferred_class[i]] > 0
3575 && ! SMALL_REGISTER_CLASS_P (preferred_class[i]))
3577 if (! reg_class_subset_p (this_alternative[i],
3578 preferred_class[i]))
3580 /* Since we don't have a way of forming the intersection,
3581 we just do something special if the preferred class
3582 is a subset of the class we have; that's the most
3583 common case anyway. */
3584 if (reg_class_subset_p (preferred_class[i],
3585 this_alternative[i]))
3586 this_alternative[i] = (int) preferred_class[i];
3587 else
3588 reject += (2 + 2 * pref_or_nothing[i]);
3593 /* Now see if any output operands that are marked "earlyclobber"
3594 in this alternative conflict with any input operands
3595 or any memory addresses. */
3597 for (i = 0; i < noperands; i++)
3598 if (this_alternative_earlyclobber[i]
3599 && (this_alternative_win[i] || this_alternative_match_win[i]))
3601 struct decomposition early_data;
3603 early_data = decompose (recog_data.operand[i]);
3605 gcc_assert (modified[i] != RELOAD_READ);
3607 if (this_alternative[i] == NO_REGS)
3609 this_alternative_earlyclobber[i] = 0;
3610 gcc_assert (this_insn_is_asm);
3611 error_for_asm (this_insn,
3612 "%<&%> constraint used with no register class");
3615 for (j = 0; j < noperands; j++)
3616 /* Is this an input operand or a memory ref? */
3617 if ((MEM_P (recog_data.operand[j])
3618 || modified[j] != RELOAD_WRITE)
3619 && j != i
3620 /* Ignore things like match_operator operands. */
3621 && *recog_data.constraints[j] != 0
3622 /* Don't count an input operand that is constrained to match
3623 the early clobber operand. */
3624 && ! (this_alternative_matches[j] == i
3625 && rtx_equal_p (recog_data.operand[i],
3626 recog_data.operand[j]))
3627 /* Is it altered by storing the earlyclobber operand? */
3628 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3629 early_data))
3631 /* If the output is in a non-empty few-regs class,
3632 it's costly to reload it, so reload the input instead. */
3633 if (SMALL_REGISTER_CLASS_P (this_alternative[i])
3634 && (REG_P (recog_data.operand[j])
3635 || GET_CODE (recog_data.operand[j]) == SUBREG))
3637 losers++;
3638 this_alternative_win[j] = 0;
3639 this_alternative_match_win[j] = 0;
3641 else
3642 break;
3644 /* If an earlyclobber operand conflicts with something,
3645 it must be reloaded, so request this and count the cost. */
3646 if (j != noperands)
3648 losers++;
3649 this_alternative_win[i] = 0;
3650 this_alternative_match_win[j] = 0;
3651 for (j = 0; j < noperands; j++)
3652 if (this_alternative_matches[j] == i
3653 && this_alternative_match_win[j])
3655 this_alternative_win[j] = 0;
3656 this_alternative_match_win[j] = 0;
3657 losers++;
3662 /* If one alternative accepts all the operands, no reload required,
3663 choose that alternative; don't consider the remaining ones. */
3664 if (losers == 0)
3666 /* Unswap these so that they are never swapped at `finish'. */
3667 if (commutative >= 0)
3669 recog_data.operand[commutative] = substed_operand[commutative];
3670 recog_data.operand[commutative + 1]
3671 = substed_operand[commutative + 1];
3673 for (i = 0; i < noperands; i++)
3675 goal_alternative_win[i] = this_alternative_win[i];
3676 goal_alternative_match_win[i] = this_alternative_match_win[i];
3677 goal_alternative[i] = this_alternative[i];
3678 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3679 goal_alternative_matches[i] = this_alternative_matches[i];
3680 goal_alternative_earlyclobber[i]
3681 = this_alternative_earlyclobber[i];
3683 goal_alternative_number = this_alternative_number;
3684 goal_alternative_swapped = swapped;
3685 goal_earlyclobber = this_earlyclobber;
3686 goto finish;
3689 /* REJECT, set by the ! and ? constraint characters and when a register
3690 would be reloaded into a non-preferred class, discourages the use of
3691 this alternative for a reload goal. REJECT is incremented by six
3692 for each ? and two for each non-preferred class. */
3693 losers = losers * 6 + reject;
3695 /* If this alternative can be made to work by reloading,
3696 and it needs less reloading than the others checked so far,
3697 record it as the chosen goal for reloading. */
3698 if (! bad && best > losers)
3700 for (i = 0; i < noperands; i++)
3702 goal_alternative[i] = this_alternative[i];
3703 goal_alternative_win[i] = this_alternative_win[i];
3704 goal_alternative_match_win[i] = this_alternative_match_win[i];
3705 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3706 goal_alternative_matches[i] = this_alternative_matches[i];
3707 goal_alternative_earlyclobber[i]
3708 = this_alternative_earlyclobber[i];
3710 goal_alternative_swapped = swapped;
3711 best = losers;
3712 goal_alternative_number = this_alternative_number;
3713 goal_earlyclobber = this_earlyclobber;
3717 /* If insn is commutative (it's safe to exchange a certain pair of operands)
3718 then we need to try each alternative twice,
3719 the second time matching those two operands
3720 as if we had exchanged them.
3721 To do this, really exchange them in operands.
3723 If we have just tried the alternatives the second time,
3724 return operands to normal and drop through. */
3726 if (commutative >= 0)
3728 swapped = !swapped;
3729 if (swapped)
3731 enum reg_class tclass;
3732 int t;
3734 recog_data.operand[commutative] = substed_operand[commutative + 1];
3735 recog_data.operand[commutative + 1] = substed_operand[commutative];
3736 /* Swap the duplicates too. */
3737 for (i = 0; i < recog_data.n_dups; i++)
3738 if (recog_data.dup_num[i] == commutative
3739 || recog_data.dup_num[i] == commutative + 1)
3740 *recog_data.dup_loc[i]
3741 = recog_data.operand[(int) recog_data.dup_num[i]];
3743 tclass = preferred_class[commutative];
3744 preferred_class[commutative] = preferred_class[commutative + 1];
3745 preferred_class[commutative + 1] = tclass;
3747 t = pref_or_nothing[commutative];
3748 pref_or_nothing[commutative] = pref_or_nothing[commutative + 1];
3749 pref_or_nothing[commutative + 1] = t;
3751 t = address_reloaded[commutative];
3752 address_reloaded[commutative] = address_reloaded[commutative + 1];
3753 address_reloaded[commutative + 1] = t;
3755 memcpy (constraints, recog_data.constraints,
3756 noperands * sizeof (const char *));
3757 goto try_swapped;
3759 else
3761 recog_data.operand[commutative] = substed_operand[commutative];
3762 recog_data.operand[commutative + 1]
3763 = substed_operand[commutative + 1];
3764 /* Unswap the duplicates too. */
3765 for (i = 0; i < recog_data.n_dups; i++)
3766 if (recog_data.dup_num[i] == commutative
3767 || recog_data.dup_num[i] == commutative + 1)
3768 *recog_data.dup_loc[i]
3769 = recog_data.operand[(int) recog_data.dup_num[i]];
3773 /* The operands don't meet the constraints.
3774 goal_alternative describes the alternative
3775 that we could reach by reloading the fewest operands.
3776 Reload so as to fit it. */
3778 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3780 /* No alternative works with reloads?? */
3781 if (insn_code_number >= 0)
3782 fatal_insn ("unable to generate reloads for:", insn);
3783 error_for_asm (insn, "inconsistent operand constraints in an %<asm%>");
3784 /* Avoid further trouble with this insn. */
3785 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3786 n_reloads = 0;
3787 return 0;
3790 /* Jump to `finish' from above if all operands are valid already.
3791 In that case, goal_alternative_win is all 1. */
3792 finish:
3794 /* Right now, for any pair of operands I and J that are required to match,
3795 with I < J,
3796 goal_alternative_matches[J] is I.
3797 Set up goal_alternative_matched as the inverse function:
3798 goal_alternative_matched[I] = J. */
3800 for (i = 0; i < noperands; i++)
3801 goal_alternative_matched[i] = -1;
3803 for (i = 0; i < noperands; i++)
3804 if (! goal_alternative_win[i]
3805 && goal_alternative_matches[i] >= 0)
3806 goal_alternative_matched[goal_alternative_matches[i]] = i;
3808 for (i = 0; i < noperands; i++)
3809 goal_alternative_win[i] |= goal_alternative_match_win[i];
3811 /* If the best alternative is with operands 1 and 2 swapped,
3812 consider them swapped before reporting the reloads. Update the
3813 operand numbers of any reloads already pushed. */
3815 if (goal_alternative_swapped)
3817 rtx tem;
3819 tem = substed_operand[commutative];
3820 substed_operand[commutative] = substed_operand[commutative + 1];
3821 substed_operand[commutative + 1] = tem;
3822 tem = recog_data.operand[commutative];
3823 recog_data.operand[commutative] = recog_data.operand[commutative + 1];
3824 recog_data.operand[commutative + 1] = tem;
3825 tem = *recog_data.operand_loc[commutative];
3826 *recog_data.operand_loc[commutative]
3827 = *recog_data.operand_loc[commutative + 1];
3828 *recog_data.operand_loc[commutative + 1] = tem;
3830 for (i = 0; i < n_reloads; i++)
3832 if (rld[i].opnum == commutative)
3833 rld[i].opnum = commutative + 1;
3834 else if (rld[i].opnum == commutative + 1)
3835 rld[i].opnum = commutative;
3839 for (i = 0; i < noperands; i++)
3841 operand_reloadnum[i] = -1;
3843 /* If this is an earlyclobber operand, we need to widen the scope.
3844 The reload must remain valid from the start of the insn being
3845 reloaded until after the operand is stored into its destination.
3846 We approximate this with RELOAD_OTHER even though we know that we
3847 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3849 One special case that is worth checking is when we have an
3850 output that is earlyclobber but isn't used past the insn (typically
3851 a SCRATCH). In this case, we only need have the reload live
3852 through the insn itself, but not for any of our input or output
3853 reloads.
3854 But we must not accidentally narrow the scope of an existing
3855 RELOAD_OTHER reload - leave these alone.
3857 In any case, anything needed to address this operand can remain
3858 however they were previously categorized. */
3860 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3861 operand_type[i]
3862 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3863 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3866 /* Any constants that aren't allowed and can't be reloaded
3867 into registers are here changed into memory references. */
3868 for (i = 0; i < noperands; i++)
3869 if (! goal_alternative_win[i])
3871 rtx op = recog_data.operand[i];
3872 rtx subreg = NULL_RTX;
3873 rtx plus = NULL_RTX;
3874 enum machine_mode mode = operand_mode[i];
3876 /* Reloads of SUBREGs of CONSTANT RTXs are handled later in
3877 push_reload so we have to let them pass here. */
3878 if (GET_CODE (op) == SUBREG)
3880 subreg = op;
3881 op = SUBREG_REG (op);
3882 mode = GET_MODE (op);
3885 if (GET_CODE (op) == PLUS)
3887 plus = op;
3888 op = XEXP (op, 1);
3891 if (CONST_POOL_OK_P (op)
3892 && ((PREFERRED_RELOAD_CLASS (op,
3893 (enum reg_class) goal_alternative[i])
3894 == NO_REGS)
3895 || no_input_reloads)
3896 && mode != VOIDmode)
3898 int this_address_reloaded;
3899 rtx tem = force_const_mem (mode, op);
3901 /* If we stripped a SUBREG or a PLUS above add it back. */
3902 if (plus != NULL_RTX)
3903 tem = gen_rtx_PLUS (mode, XEXP (plus, 0), tem);
3905 if (subreg != NULL_RTX)
3906 tem = gen_rtx_SUBREG (operand_mode[i], tem, SUBREG_BYTE (subreg));
3908 this_address_reloaded = 0;
3909 substed_operand[i] = recog_data.operand[i]
3910 = find_reloads_toplev (tem, i, address_type[i], ind_levels,
3911 0, insn, &this_address_reloaded);
3913 /* If the alternative accepts constant pool refs directly
3914 there will be no reload needed at all. */
3915 if (plus == NULL_RTX
3916 && subreg == NULL_RTX
3917 && alternative_allows_const_pool_ref (this_address_reloaded == 0
3918 ? substed_operand[i]
3919 : NULL,
3920 recog_data.constraints[i],
3921 goal_alternative_number))
3922 goal_alternative_win[i] = 1;
3926 /* Record the values of the earlyclobber operands for the caller. */
3927 if (goal_earlyclobber)
3928 for (i = 0; i < noperands; i++)
3929 if (goal_alternative_earlyclobber[i])
3930 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3932 /* Now record reloads for all the operands that need them. */
3933 for (i = 0; i < noperands; i++)
3934 if (! goal_alternative_win[i])
3936 /* Operands that match previous ones have already been handled. */
3937 if (goal_alternative_matches[i] >= 0)
3939 /* Handle an operand with a nonoffsettable address
3940 appearing where an offsettable address will do
3941 by reloading the address into a base register.
3943 ??? We can also do this when the operand is a register and
3944 reg_equiv_mem is not offsettable, but this is a bit tricky,
3945 so we don't bother with it. It may not be worth doing. */
3946 else if (goal_alternative_matched[i] == -1
3947 && goal_alternative_offmemok[i]
3948 && MEM_P (recog_data.operand[i]))
3950 /* If the address to be reloaded is a VOIDmode constant,
3951 use Pmode as mode of the reload register, as would have
3952 been done by find_reloads_address. */
3953 enum machine_mode address_mode;
3954 address_mode = GET_MODE (XEXP (recog_data.operand[i], 0));
3955 if (address_mode == VOIDmode)
3956 address_mode = Pmode;
3958 operand_reloadnum[i]
3959 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
3960 &XEXP (recog_data.operand[i], 0), (rtx*) 0,
3961 base_reg_class (VOIDmode, MEM, SCRATCH),
3962 address_mode,
3963 VOIDmode, 0, 0, i, RELOAD_FOR_INPUT);
3964 rld[operand_reloadnum[i]].inc
3965 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
3967 /* If this operand is an output, we will have made any
3968 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
3969 now we are treating part of the operand as an input, so
3970 we must change these to RELOAD_FOR_INPUT_ADDRESS. */
3972 if (modified[i] == RELOAD_WRITE)
3974 for (j = 0; j < n_reloads; j++)
3976 if (rld[j].opnum == i)
3978 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
3979 rld[j].when_needed = RELOAD_FOR_INPUT_ADDRESS;
3980 else if (rld[j].when_needed
3981 == RELOAD_FOR_OUTADDR_ADDRESS)
3982 rld[j].when_needed = RELOAD_FOR_INPADDR_ADDRESS;
3987 else if (goal_alternative_matched[i] == -1)
3989 operand_reloadnum[i]
3990 = push_reload ((modified[i] != RELOAD_WRITE
3991 ? recog_data.operand[i] : 0),
3992 (modified[i] != RELOAD_READ
3993 ? recog_data.operand[i] : 0),
3994 (modified[i] != RELOAD_WRITE
3995 ? recog_data.operand_loc[i] : 0),
3996 (modified[i] != RELOAD_READ
3997 ? recog_data.operand_loc[i] : 0),
3998 (enum reg_class) goal_alternative[i],
3999 (modified[i] == RELOAD_WRITE
4000 ? VOIDmode : operand_mode[i]),
4001 (modified[i] == RELOAD_READ
4002 ? VOIDmode : operand_mode[i]),
4003 (insn_code_number < 0 ? 0
4004 : insn_data[insn_code_number].operand[i].strict_low),
4005 0, i, operand_type[i]);
4007 /* In a matching pair of operands, one must be input only
4008 and the other must be output only.
4009 Pass the input operand as IN and the other as OUT. */
4010 else if (modified[i] == RELOAD_READ
4011 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
4013 operand_reloadnum[i]
4014 = push_reload (recog_data.operand[i],
4015 recog_data.operand[goal_alternative_matched[i]],
4016 recog_data.operand_loc[i],
4017 recog_data.operand_loc[goal_alternative_matched[i]],
4018 (enum reg_class) goal_alternative[i],
4019 operand_mode[i],
4020 operand_mode[goal_alternative_matched[i]],
4021 0, 0, i, RELOAD_OTHER);
4022 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
4024 else if (modified[i] == RELOAD_WRITE
4025 && modified[goal_alternative_matched[i]] == RELOAD_READ)
4027 operand_reloadnum[goal_alternative_matched[i]]
4028 = push_reload (recog_data.operand[goal_alternative_matched[i]],
4029 recog_data.operand[i],
4030 recog_data.operand_loc[goal_alternative_matched[i]],
4031 recog_data.operand_loc[i],
4032 (enum reg_class) goal_alternative[i],
4033 operand_mode[goal_alternative_matched[i]],
4034 operand_mode[i],
4035 0, 0, i, RELOAD_OTHER);
4036 operand_reloadnum[i] = output_reloadnum;
4038 else
4040 gcc_assert (insn_code_number < 0);
4041 error_for_asm (insn, "inconsistent operand constraints "
4042 "in an %<asm%>");
4043 /* Avoid further trouble with this insn. */
4044 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
4045 n_reloads = 0;
4046 return 0;
4049 else if (goal_alternative_matched[i] < 0
4050 && goal_alternative_matches[i] < 0
4051 && address_operand_reloaded[i] != 1
4052 && optimize)
4054 /* For each non-matching operand that's a MEM or a pseudo-register
4055 that didn't get a hard register, make an optional reload.
4056 This may get done even if the insn needs no reloads otherwise. */
4058 rtx operand = recog_data.operand[i];
4060 while (GET_CODE (operand) == SUBREG)
4061 operand = SUBREG_REG (operand);
4062 if ((MEM_P (operand)
4063 || (REG_P (operand)
4064 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4065 /* If this is only for an output, the optional reload would not
4066 actually cause us to use a register now, just note that
4067 something is stored here. */
4068 && ((enum reg_class) goal_alternative[i] != NO_REGS
4069 || modified[i] == RELOAD_WRITE)
4070 && ! no_input_reloads
4071 /* An optional output reload might allow to delete INSN later.
4072 We mustn't make in-out reloads on insns that are not permitted
4073 output reloads.
4074 If this is an asm, we can't delete it; we must not even call
4075 push_reload for an optional output reload in this case,
4076 because we can't be sure that the constraint allows a register,
4077 and push_reload verifies the constraints for asms. */
4078 && (modified[i] == RELOAD_READ
4079 || (! no_output_reloads && ! this_insn_is_asm)))
4080 operand_reloadnum[i]
4081 = push_reload ((modified[i] != RELOAD_WRITE
4082 ? recog_data.operand[i] : 0),
4083 (modified[i] != RELOAD_READ
4084 ? recog_data.operand[i] : 0),
4085 (modified[i] != RELOAD_WRITE
4086 ? recog_data.operand_loc[i] : 0),
4087 (modified[i] != RELOAD_READ
4088 ? recog_data.operand_loc[i] : 0),
4089 (enum reg_class) goal_alternative[i],
4090 (modified[i] == RELOAD_WRITE
4091 ? VOIDmode : operand_mode[i]),
4092 (modified[i] == RELOAD_READ
4093 ? VOIDmode : operand_mode[i]),
4094 (insn_code_number < 0 ? 0
4095 : insn_data[insn_code_number].operand[i].strict_low),
4096 1, i, operand_type[i]);
4097 /* If a memory reference remains (either as a MEM or a pseudo that
4098 did not get a hard register), yet we can't make an optional
4099 reload, check if this is actually a pseudo register reference;
4100 we then need to emit a USE and/or a CLOBBER so that reload
4101 inheritance will do the right thing. */
4102 else if (replace
4103 && (MEM_P (operand)
4104 || (REG_P (operand)
4105 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
4106 && reg_renumber [REGNO (operand)] < 0)))
4108 operand = *recog_data.operand_loc[i];
4110 while (GET_CODE (operand) == SUBREG)
4111 operand = SUBREG_REG (operand);
4112 if (REG_P (operand))
4114 if (modified[i] != RELOAD_WRITE)
4115 /* We mark the USE with QImode so that we recognize
4116 it as one that can be safely deleted at the end
4117 of reload. */
4118 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, operand),
4119 insn), QImode);
4120 if (modified[i] != RELOAD_READ)
4121 emit_insn_after (gen_clobber (operand), insn);
4125 else if (goal_alternative_matches[i] >= 0
4126 && goal_alternative_win[goal_alternative_matches[i]]
4127 && modified[i] == RELOAD_READ
4128 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
4129 && ! no_input_reloads && ! no_output_reloads
4130 && optimize)
4132 /* Similarly, make an optional reload for a pair of matching
4133 objects that are in MEM or a pseudo that didn't get a hard reg. */
4135 rtx operand = recog_data.operand[i];
4137 while (GET_CODE (operand) == SUBREG)
4138 operand = SUBREG_REG (operand);
4139 if ((MEM_P (operand)
4140 || (REG_P (operand)
4141 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4142 && ((enum reg_class) goal_alternative[goal_alternative_matches[i]]
4143 != NO_REGS))
4144 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
4145 = push_reload (recog_data.operand[goal_alternative_matches[i]],
4146 recog_data.operand[i],
4147 recog_data.operand_loc[goal_alternative_matches[i]],
4148 recog_data.operand_loc[i],
4149 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
4150 operand_mode[goal_alternative_matches[i]],
4151 operand_mode[i],
4152 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
4155 /* Perform whatever substitutions on the operands we are supposed
4156 to make due to commutativity or replacement of registers
4157 with equivalent constants or memory slots. */
4159 for (i = 0; i < noperands; i++)
4161 /* We only do this on the last pass through reload, because it is
4162 possible for some data (like reg_equiv_address) to be changed during
4163 later passes. Moreover, we lose the opportunity to get a useful
4164 reload_{in,out}_reg when we do these replacements. */
4166 if (replace)
4168 rtx substitution = substed_operand[i];
4170 *recog_data.operand_loc[i] = substitution;
4172 /* If we're replacing an operand with a LABEL_REF, we need to
4173 make sure that there's a REG_LABEL_OPERAND note attached to
4174 this instruction. */
4175 if (GET_CODE (substitution) == LABEL_REF
4176 && !find_reg_note (insn, REG_LABEL_OPERAND,
4177 XEXP (substitution, 0))
4178 /* For a JUMP_P, if it was a branch target it must have
4179 already been recorded as such. */
4180 && (!JUMP_P (insn)
4181 || !label_is_jump_target_p (XEXP (substitution, 0),
4182 insn)))
4183 add_reg_note (insn, REG_LABEL_OPERAND, XEXP (substitution, 0));
4185 else
4186 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
4189 /* If this insn pattern contains any MATCH_DUP's, make sure that
4190 they will be substituted if the operands they match are substituted.
4191 Also do now any substitutions we already did on the operands.
4193 Don't do this if we aren't making replacements because we might be
4194 propagating things allocated by frame pointer elimination into places
4195 it doesn't expect. */
4197 if (insn_code_number >= 0 && replace)
4198 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
4200 int opno = recog_data.dup_num[i];
4201 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
4202 dup_replacements (recog_data.dup_loc[i], recog_data.operand_loc[opno]);
4205 #if 0
4206 /* This loses because reloading of prior insns can invalidate the equivalence
4207 (or at least find_equiv_reg isn't smart enough to find it any more),
4208 causing this insn to need more reload regs than it needed before.
4209 It may be too late to make the reload regs available.
4210 Now this optimization is done safely in choose_reload_regs. */
4212 /* For each reload of a reg into some other class of reg,
4213 search for an existing equivalent reg (same value now) in the right class.
4214 We can use it as long as we don't need to change its contents. */
4215 for (i = 0; i < n_reloads; i++)
4216 if (rld[i].reg_rtx == 0
4217 && rld[i].in != 0
4218 && REG_P (rld[i].in)
4219 && rld[i].out == 0)
4221 rld[i].reg_rtx
4222 = find_equiv_reg (rld[i].in, insn, rld[i].rclass, -1,
4223 static_reload_reg_p, 0, rld[i].inmode);
4224 /* Prevent generation of insn to load the value
4225 because the one we found already has the value. */
4226 if (rld[i].reg_rtx)
4227 rld[i].in = rld[i].reg_rtx;
4229 #endif
4231 /* If we detected error and replaced asm instruction by USE, forget about the
4232 reloads. */
4233 if (GET_CODE (PATTERN (insn)) == USE
4234 && GET_CODE (XEXP (PATTERN (insn), 0)) == CONST_INT)
4235 n_reloads = 0;
4237 /* Perhaps an output reload can be combined with another
4238 to reduce needs by one. */
4239 if (!goal_earlyclobber)
4240 combine_reloads ();
4242 /* If we have a pair of reloads for parts of an address, they are reloading
4243 the same object, the operands themselves were not reloaded, and they
4244 are for two operands that are supposed to match, merge the reloads and
4245 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
4247 for (i = 0; i < n_reloads; i++)
4249 int k;
4251 for (j = i + 1; j < n_reloads; j++)
4252 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4253 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4254 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4255 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4256 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
4257 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4258 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4259 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4260 && rtx_equal_p (rld[i].in, rld[j].in)
4261 && (operand_reloadnum[rld[i].opnum] < 0
4262 || rld[operand_reloadnum[rld[i].opnum]].optional)
4263 && (operand_reloadnum[rld[j].opnum] < 0
4264 || rld[operand_reloadnum[rld[j].opnum]].optional)
4265 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
4266 || (goal_alternative_matches[rld[j].opnum]
4267 == rld[i].opnum)))
4269 for (k = 0; k < n_replacements; k++)
4270 if (replacements[k].what == j)
4271 replacements[k].what = i;
4273 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4274 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4275 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4276 else
4277 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4278 rld[j].in = 0;
4282 /* Scan all the reloads and update their type.
4283 If a reload is for the address of an operand and we didn't reload
4284 that operand, change the type. Similarly, change the operand number
4285 of a reload when two operands match. If a reload is optional, treat it
4286 as though the operand isn't reloaded.
4288 ??? This latter case is somewhat odd because if we do the optional
4289 reload, it means the object is hanging around. Thus we need only
4290 do the address reload if the optional reload was NOT done.
4292 Change secondary reloads to be the address type of their operand, not
4293 the normal type.
4295 If an operand's reload is now RELOAD_OTHER, change any
4296 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
4297 RELOAD_FOR_OTHER_ADDRESS. */
4299 for (i = 0; i < n_reloads; i++)
4301 if (rld[i].secondary_p
4302 && rld[i].when_needed == operand_type[rld[i].opnum])
4303 rld[i].when_needed = address_type[rld[i].opnum];
4305 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4306 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4307 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4308 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4309 && (operand_reloadnum[rld[i].opnum] < 0
4310 || rld[operand_reloadnum[rld[i].opnum]].optional))
4312 /* If we have a secondary reload to go along with this reload,
4313 change its type to RELOAD_FOR_OPADDR_ADDR. */
4315 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4316 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4317 && rld[i].secondary_in_reload != -1)
4319 int secondary_in_reload = rld[i].secondary_in_reload;
4321 rld[secondary_in_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4323 /* If there's a tertiary reload we have to change it also. */
4324 if (secondary_in_reload > 0
4325 && rld[secondary_in_reload].secondary_in_reload != -1)
4326 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
4327 = RELOAD_FOR_OPADDR_ADDR;
4330 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4331 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4332 && rld[i].secondary_out_reload != -1)
4334 int secondary_out_reload = rld[i].secondary_out_reload;
4336 rld[secondary_out_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4338 /* If there's a tertiary reload we have to change it also. */
4339 if (secondary_out_reload
4340 && rld[secondary_out_reload].secondary_out_reload != -1)
4341 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
4342 = RELOAD_FOR_OPADDR_ADDR;
4345 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4346 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4347 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4348 else
4349 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4352 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4353 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4354 && operand_reloadnum[rld[i].opnum] >= 0
4355 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
4356 == RELOAD_OTHER))
4357 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4359 if (goal_alternative_matches[rld[i].opnum] >= 0)
4360 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
4363 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
4364 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
4365 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
4367 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
4368 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
4369 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
4370 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
4371 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
4372 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
4373 This is complicated by the fact that a single operand can have more
4374 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
4375 choose_reload_regs without affecting code quality, and cases that
4376 actually fail are extremely rare, so it turns out to be better to fix
4377 the problem here by not generating cases that choose_reload_regs will
4378 fail for. */
4379 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
4380 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
4381 a single operand.
4382 We can reduce the register pressure by exploiting that a
4383 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4384 does not conflict with any of them, if it is only used for the first of
4385 the RELOAD_FOR_X_ADDRESS reloads. */
4387 int first_op_addr_num = -2;
4388 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4389 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4390 int need_change = 0;
4391 /* We use last_op_addr_reload and the contents of the above arrays
4392 first as flags - -2 means no instance encountered, -1 means exactly
4393 one instance encountered.
4394 If more than one instance has been encountered, we store the reload
4395 number of the first reload of the kind in question; reload numbers
4396 are known to be non-negative. */
4397 for (i = 0; i < noperands; i++)
4398 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4399 for (i = n_reloads - 1; i >= 0; i--)
4401 switch (rld[i].when_needed)
4403 case RELOAD_FOR_OPERAND_ADDRESS:
4404 if (++first_op_addr_num >= 0)
4406 first_op_addr_num = i;
4407 need_change = 1;
4409 break;
4410 case RELOAD_FOR_INPUT_ADDRESS:
4411 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4413 first_inpaddr_num[rld[i].opnum] = i;
4414 need_change = 1;
4416 break;
4417 case RELOAD_FOR_OUTPUT_ADDRESS:
4418 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4420 first_outpaddr_num[rld[i].opnum] = i;
4421 need_change = 1;
4423 break;
4424 default:
4425 break;
4429 if (need_change)
4431 for (i = 0; i < n_reloads; i++)
4433 int first_num;
4434 enum reload_type type;
4436 switch (rld[i].when_needed)
4438 case RELOAD_FOR_OPADDR_ADDR:
4439 first_num = first_op_addr_num;
4440 type = RELOAD_FOR_OPERAND_ADDRESS;
4441 break;
4442 case RELOAD_FOR_INPADDR_ADDRESS:
4443 first_num = first_inpaddr_num[rld[i].opnum];
4444 type = RELOAD_FOR_INPUT_ADDRESS;
4445 break;
4446 case RELOAD_FOR_OUTADDR_ADDRESS:
4447 first_num = first_outpaddr_num[rld[i].opnum];
4448 type = RELOAD_FOR_OUTPUT_ADDRESS;
4449 break;
4450 default:
4451 continue;
4453 if (first_num < 0)
4454 continue;
4455 else if (i > first_num)
4456 rld[i].when_needed = type;
4457 else
4459 /* Check if the only TYPE reload that uses reload I is
4460 reload FIRST_NUM. */
4461 for (j = n_reloads - 1; j > first_num; j--)
4463 if (rld[j].when_needed == type
4464 && (rld[i].secondary_p
4465 ? rld[j].secondary_in_reload == i
4466 : reg_mentioned_p (rld[i].in, rld[j].in)))
4468 rld[i].when_needed = type;
4469 break;
4477 /* See if we have any reloads that are now allowed to be merged
4478 because we've changed when the reload is needed to
4479 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4480 check for the most common cases. */
4482 for (i = 0; i < n_reloads; i++)
4483 if (rld[i].in != 0 && rld[i].out == 0
4484 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4485 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4486 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4487 for (j = 0; j < n_reloads; j++)
4488 if (i != j && rld[j].in != 0 && rld[j].out == 0
4489 && rld[j].when_needed == rld[i].when_needed
4490 && MATCHES (rld[i].in, rld[j].in)
4491 && rld[i].rclass == rld[j].rclass
4492 && !rld[i].nocombine && !rld[j].nocombine
4493 && rld[i].reg_rtx == rld[j].reg_rtx)
4495 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4496 transfer_replacements (i, j);
4497 rld[j].in = 0;
4500 #ifdef HAVE_cc0
4501 /* If we made any reloads for addresses, see if they violate a
4502 "no input reloads" requirement for this insn. But loads that we
4503 do after the insn (such as for output addresses) are fine. */
4504 if (no_input_reloads)
4505 for (i = 0; i < n_reloads; i++)
4506 gcc_assert (rld[i].in == 0
4507 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS
4508 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS);
4509 #endif
4511 /* Compute reload_mode and reload_nregs. */
4512 for (i = 0; i < n_reloads; i++)
4514 rld[i].mode
4515 = (rld[i].inmode == VOIDmode
4516 || (GET_MODE_SIZE (rld[i].outmode)
4517 > GET_MODE_SIZE (rld[i].inmode)))
4518 ? rld[i].outmode : rld[i].inmode;
4520 rld[i].nregs = CLASS_MAX_NREGS (rld[i].rclass, rld[i].mode);
4523 /* Special case a simple move with an input reload and a
4524 destination of a hard reg, if the hard reg is ok, use it. */
4525 for (i = 0; i < n_reloads; i++)
4526 if (rld[i].when_needed == RELOAD_FOR_INPUT
4527 && GET_CODE (PATTERN (insn)) == SET
4528 && REG_P (SET_DEST (PATTERN (insn)))
4529 && (SET_SRC (PATTERN (insn)) == rld[i].in
4530 || SET_SRC (PATTERN (insn)) == rld[i].in_reg)
4531 && !elimination_target_reg_p (SET_DEST (PATTERN (insn))))
4533 rtx dest = SET_DEST (PATTERN (insn));
4534 unsigned int regno = REGNO (dest);
4536 if (regno < FIRST_PSEUDO_REGISTER
4537 && TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno)
4538 && HARD_REGNO_MODE_OK (regno, rld[i].mode))
4540 int nr = hard_regno_nregs[regno][rld[i].mode];
4541 int ok = 1, nri;
4543 for (nri = 1; nri < nr; nri ++)
4544 if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno + nri))
4545 ok = 0;
4547 if (ok)
4548 rld[i].reg_rtx = dest;
4552 return retval;
4555 /* Return true if alternative number ALTNUM in constraint-string
4556 CONSTRAINT is guaranteed to accept a reloaded constant-pool reference.
4557 MEM gives the reference if it didn't need any reloads, otherwise it
4558 is null. */
4560 static bool
4561 alternative_allows_const_pool_ref (rtx mem, const char *constraint, int altnum)
4563 int c;
4565 /* Skip alternatives before the one requested. */
4566 while (altnum > 0)
4568 while (*constraint++ != ',');
4569 altnum--;
4571 /* Scan the requested alternative for TARGET_MEM_CONSTRAINT or 'o'.
4572 If one of them is present, this alternative accepts the result of
4573 passing a constant-pool reference through find_reloads_toplev.
4575 The same is true of extra memory constraints if the address
4576 was reloaded into a register. However, the target may elect
4577 to disallow the original constant address, forcing it to be
4578 reloaded into a register instead. */
4579 for (; (c = *constraint) && c != ',' && c != '#';
4580 constraint += CONSTRAINT_LEN (c, constraint))
4582 if (c == TARGET_MEM_CONSTRAINT || c == 'o')
4583 return true;
4584 #ifdef EXTRA_CONSTRAINT_STR
4585 if (EXTRA_MEMORY_CONSTRAINT (c, constraint)
4586 && (mem == NULL || EXTRA_CONSTRAINT_STR (mem, c, constraint)))
4587 return true;
4588 #endif
4590 return false;
4593 /* Scan X for memory references and scan the addresses for reloading.
4594 Also checks for references to "constant" regs that we want to eliminate
4595 and replaces them with the values they stand for.
4596 We may alter X destructively if it contains a reference to such.
4597 If X is just a constant reg, we return the equivalent value
4598 instead of X.
4600 IND_LEVELS says how many levels of indirect addressing this machine
4601 supports.
4603 OPNUM and TYPE identify the purpose of the reload.
4605 IS_SET_DEST is true if X is the destination of a SET, which is not
4606 appropriate to be replaced by a constant.
4608 INSN, if nonzero, is the insn in which we do the reload. It is used
4609 to determine if we may generate output reloads, and where to put USEs
4610 for pseudos that we have to replace with stack slots.
4612 ADDRESS_RELOADED. If nonzero, is a pointer to where we put the
4613 result of find_reloads_address. */
4615 static rtx
4616 find_reloads_toplev (rtx x, int opnum, enum reload_type type,
4617 int ind_levels, int is_set_dest, rtx insn,
4618 int *address_reloaded)
4620 RTX_CODE code = GET_CODE (x);
4622 const char *fmt = GET_RTX_FORMAT (code);
4623 int i;
4624 int copied;
4626 if (code == REG)
4628 /* This code is duplicated for speed in find_reloads. */
4629 int regno = REGNO (x);
4630 if (reg_equiv_constant[regno] != 0 && !is_set_dest)
4631 x = reg_equiv_constant[regno];
4632 #if 0
4633 /* This creates (subreg (mem...)) which would cause an unnecessary
4634 reload of the mem. */
4635 else if (reg_equiv_mem[regno] != 0)
4636 x = reg_equiv_mem[regno];
4637 #endif
4638 else if (reg_equiv_memory_loc[regno]
4639 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
4641 rtx mem = make_memloc (x, regno);
4642 if (reg_equiv_address[regno]
4643 || ! rtx_equal_p (mem, reg_equiv_mem[regno]))
4645 /* If this is not a toplevel operand, find_reloads doesn't see
4646 this substitution. We have to emit a USE of the pseudo so
4647 that delete_output_reload can see it. */
4648 if (replace_reloads && recog_data.operand[opnum] != x)
4649 /* We mark the USE with QImode so that we recognize it
4650 as one that can be safely deleted at the end of
4651 reload. */
4652 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, x), insn),
4653 QImode);
4654 x = mem;
4655 i = find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4656 opnum, type, ind_levels, insn);
4657 if (!rtx_equal_p (x, mem))
4658 push_reg_equiv_alt_mem (regno, x);
4659 if (address_reloaded)
4660 *address_reloaded = i;
4663 return x;
4665 if (code == MEM)
4667 rtx tem = x;
4669 i = find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4670 opnum, type, ind_levels, insn);
4671 if (address_reloaded)
4672 *address_reloaded = i;
4674 return tem;
4677 if (code == SUBREG && REG_P (SUBREG_REG (x)))
4679 /* Check for SUBREG containing a REG that's equivalent to a
4680 constant. If the constant has a known value, truncate it
4681 right now. Similarly if we are extracting a single-word of a
4682 multi-word constant. If the constant is symbolic, allow it
4683 to be substituted normally. push_reload will strip the
4684 subreg later. The constant must not be VOIDmode, because we
4685 will lose the mode of the register (this should never happen
4686 because one of the cases above should handle it). */
4688 int regno = REGNO (SUBREG_REG (x));
4689 rtx tem;
4691 if (regno >= FIRST_PSEUDO_REGISTER
4692 && reg_renumber[regno] < 0
4693 && reg_equiv_constant[regno] != 0)
4695 tem =
4696 simplify_gen_subreg (GET_MODE (x), reg_equiv_constant[regno],
4697 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
4698 gcc_assert (tem);
4699 if (CONSTANT_P (tem) && !LEGITIMATE_CONSTANT_P (tem))
4701 tem = force_const_mem (GET_MODE (x), tem);
4702 i = find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4703 &XEXP (tem, 0), opnum, type,
4704 ind_levels, insn);
4705 if (address_reloaded)
4706 *address_reloaded = i;
4708 return tem;
4711 /* If the subreg contains a reg that will be converted to a mem,
4712 convert the subreg to a narrower memref now.
4713 Otherwise, we would get (subreg (mem ...) ...),
4714 which would force reload of the mem.
4716 We also need to do this if there is an equivalent MEM that is
4717 not offsettable. In that case, alter_subreg would produce an
4718 invalid address on big-endian machines.
4720 For machines that extend byte loads, we must not reload using
4721 a wider mode if we have a paradoxical SUBREG. find_reloads will
4722 force a reload in that case. So we should not do anything here. */
4724 if (regno >= FIRST_PSEUDO_REGISTER
4725 #ifdef LOAD_EXTEND_OP
4726 && (GET_MODE_SIZE (GET_MODE (x))
4727 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
4728 #endif
4729 && (reg_equiv_address[regno] != 0
4730 || (reg_equiv_mem[regno] != 0
4731 && (! strict_memory_address_p (GET_MODE (x),
4732 XEXP (reg_equiv_mem[regno], 0))
4733 || ! offsettable_memref_p (reg_equiv_mem[regno])
4734 || num_not_at_initial_offset))))
4735 x = find_reloads_subreg_address (x, 1, opnum, type, ind_levels,
4736 insn);
4739 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4741 if (fmt[i] == 'e')
4743 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4744 ind_levels, is_set_dest, insn,
4745 address_reloaded);
4746 /* If we have replaced a reg with it's equivalent memory loc -
4747 that can still be handled here e.g. if it's in a paradoxical
4748 subreg - we must make the change in a copy, rather than using
4749 a destructive change. This way, find_reloads can still elect
4750 not to do the change. */
4751 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4753 x = shallow_copy_rtx (x);
4754 copied = 1;
4756 XEXP (x, i) = new_part;
4759 return x;
4762 /* Return a mem ref for the memory equivalent of reg REGNO.
4763 This mem ref is not shared with anything. */
4765 static rtx
4766 make_memloc (rtx ad, int regno)
4768 /* We must rerun eliminate_regs, in case the elimination
4769 offsets have changed. */
4770 rtx tem
4771 = XEXP (eliminate_regs (reg_equiv_memory_loc[regno], 0, NULL_RTX), 0);
4773 /* If TEM might contain a pseudo, we must copy it to avoid
4774 modifying it when we do the substitution for the reload. */
4775 if (rtx_varies_p (tem, 0))
4776 tem = copy_rtx (tem);
4778 tem = replace_equiv_address_nv (reg_equiv_memory_loc[regno], tem);
4779 tem = adjust_address_nv (tem, GET_MODE (ad), 0);
4781 /* Copy the result if it's still the same as the equivalence, to avoid
4782 modifying it when we do the substitution for the reload. */
4783 if (tem == reg_equiv_memory_loc[regno])
4784 tem = copy_rtx (tem);
4785 return tem;
4788 /* Returns true if AD could be turned into a valid memory reference
4789 to mode MODE by reloading the part pointed to by PART into a
4790 register. */
4792 static int
4793 maybe_memory_address_p (enum machine_mode mode, rtx ad, rtx *part)
4795 int retv;
4796 rtx tem = *part;
4797 rtx reg = gen_rtx_REG (GET_MODE (tem), max_reg_num ());
4799 *part = reg;
4800 retv = memory_address_p (mode, ad);
4801 *part = tem;
4803 return retv;
4806 /* Record all reloads needed for handling memory address AD
4807 which appears in *LOC in a memory reference to mode MODE
4808 which itself is found in location *MEMREFLOC.
4809 Note that we take shortcuts assuming that no multi-reg machine mode
4810 occurs as part of an address.
4812 OPNUM and TYPE specify the purpose of this reload.
4814 IND_LEVELS says how many levels of indirect addressing this machine
4815 supports.
4817 INSN, if nonzero, is the insn in which we do the reload. It is used
4818 to determine if we may generate output reloads, and where to put USEs
4819 for pseudos that we have to replace with stack slots.
4821 Value is one if this address is reloaded or replaced as a whole; it is
4822 zero if the top level of this address was not reloaded or replaced, and
4823 it is -1 if it may or may not have been reloaded or replaced.
4825 Note that there is no verification that the address will be valid after
4826 this routine does its work. Instead, we rely on the fact that the address
4827 was valid when reload started. So we need only undo things that reload
4828 could have broken. These are wrong register types, pseudos not allocated
4829 to a hard register, and frame pointer elimination. */
4831 static int
4832 find_reloads_address (enum machine_mode mode, rtx *memrefloc, rtx ad,
4833 rtx *loc, int opnum, enum reload_type type,
4834 int ind_levels, rtx insn)
4836 int regno;
4837 int removed_and = 0;
4838 int op_index;
4839 rtx tem;
4841 /* If the address is a register, see if it is a legitimate address and
4842 reload if not. We first handle the cases where we need not reload
4843 or where we must reload in a non-standard way. */
4845 if (REG_P (ad))
4847 regno = REGNO (ad);
4849 if (reg_equiv_constant[regno] != 0)
4851 find_reloads_address_part (reg_equiv_constant[regno], loc,
4852 base_reg_class (mode, MEM, SCRATCH),
4853 GET_MODE (ad), opnum, type, ind_levels);
4854 return 1;
4857 tem = reg_equiv_memory_loc[regno];
4858 if (tem != 0)
4860 if (reg_equiv_address[regno] != 0 || num_not_at_initial_offset)
4862 tem = make_memloc (ad, regno);
4863 if (! strict_memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
4865 rtx orig = tem;
4867 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4868 &XEXP (tem, 0), opnum,
4869 ADDR_TYPE (type), ind_levels, insn);
4870 if (!rtx_equal_p (tem, orig))
4871 push_reg_equiv_alt_mem (regno, tem);
4873 /* We can avoid a reload if the register's equivalent memory
4874 expression is valid as an indirect memory address.
4875 But not all addresses are valid in a mem used as an indirect
4876 address: only reg or reg+constant. */
4878 if (ind_levels > 0
4879 && strict_memory_address_p (mode, tem)
4880 && (REG_P (XEXP (tem, 0))
4881 || (GET_CODE (XEXP (tem, 0)) == PLUS
4882 && REG_P (XEXP (XEXP (tem, 0), 0))
4883 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4885 /* TEM is not the same as what we'll be replacing the
4886 pseudo with after reload, put a USE in front of INSN
4887 in the final reload pass. */
4888 if (replace_reloads
4889 && num_not_at_initial_offset
4890 && ! rtx_equal_p (tem, reg_equiv_mem[regno]))
4892 *loc = tem;
4893 /* We mark the USE with QImode so that we
4894 recognize it as one that can be safely
4895 deleted at the end of reload. */
4896 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad),
4897 insn), QImode);
4899 /* This doesn't really count as replacing the address
4900 as a whole, since it is still a memory access. */
4902 return 0;
4904 ad = tem;
4908 /* The only remaining case where we can avoid a reload is if this is a
4909 hard register that is valid as a base register and which is not the
4910 subject of a CLOBBER in this insn. */
4912 else if (regno < FIRST_PSEUDO_REGISTER
4913 && regno_ok_for_base_p (regno, mode, MEM, SCRATCH)
4914 && ! regno_clobbered_p (regno, this_insn, mode, 0))
4915 return 0;
4917 /* If we do not have one of the cases above, we must do the reload. */
4918 push_reload (ad, NULL_RTX, loc, (rtx*) 0, base_reg_class (mode, MEM, SCRATCH),
4919 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4920 return 1;
4923 if (strict_memory_address_p (mode, ad))
4925 /* The address appears valid, so reloads are not needed.
4926 But the address may contain an eliminable register.
4927 This can happen because a machine with indirect addressing
4928 may consider a pseudo register by itself a valid address even when
4929 it has failed to get a hard reg.
4930 So do a tree-walk to find and eliminate all such regs. */
4932 /* But first quickly dispose of a common case. */
4933 if (GET_CODE (ad) == PLUS
4934 && GET_CODE (XEXP (ad, 1)) == CONST_INT
4935 && REG_P (XEXP (ad, 0))
4936 && reg_equiv_constant[REGNO (XEXP (ad, 0))] == 0)
4937 return 0;
4939 subst_reg_equivs_changed = 0;
4940 *loc = subst_reg_equivs (ad, insn);
4942 if (! subst_reg_equivs_changed)
4943 return 0;
4945 /* Check result for validity after substitution. */
4946 if (strict_memory_address_p (mode, ad))
4947 return 0;
4950 #ifdef LEGITIMIZE_RELOAD_ADDRESS
4953 if (memrefloc)
4955 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
4956 ind_levels, win);
4958 break;
4959 win:
4960 *memrefloc = copy_rtx (*memrefloc);
4961 XEXP (*memrefloc, 0) = ad;
4962 move_replacements (&ad, &XEXP (*memrefloc, 0));
4963 return -1;
4965 while (0);
4966 #endif
4968 /* The address is not valid. We have to figure out why. First see if
4969 we have an outer AND and remove it if so. Then analyze what's inside. */
4971 if (GET_CODE (ad) == AND)
4973 removed_and = 1;
4974 loc = &XEXP (ad, 0);
4975 ad = *loc;
4978 /* One possibility for why the address is invalid is that it is itself
4979 a MEM. This can happen when the frame pointer is being eliminated, a
4980 pseudo is not allocated to a hard register, and the offset between the
4981 frame and stack pointers is not its initial value. In that case the
4982 pseudo will have been replaced by a MEM referring to the
4983 stack pointer. */
4984 if (MEM_P (ad))
4986 /* First ensure that the address in this MEM is valid. Then, unless
4987 indirect addresses are valid, reload the MEM into a register. */
4988 tem = ad;
4989 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
4990 opnum, ADDR_TYPE (type),
4991 ind_levels == 0 ? 0 : ind_levels - 1, insn);
4993 /* If tem was changed, then we must create a new memory reference to
4994 hold it and store it back into memrefloc. */
4995 if (tem != ad && memrefloc)
4997 *memrefloc = copy_rtx (*memrefloc);
4998 copy_replacements (tem, XEXP (*memrefloc, 0));
4999 loc = &XEXP (*memrefloc, 0);
5000 if (removed_and)
5001 loc = &XEXP (*loc, 0);
5004 /* Check similar cases as for indirect addresses as above except
5005 that we can allow pseudos and a MEM since they should have been
5006 taken care of above. */
5008 if (ind_levels == 0
5009 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
5010 || MEM_P (XEXP (tem, 0))
5011 || ! (REG_P (XEXP (tem, 0))
5012 || (GET_CODE (XEXP (tem, 0)) == PLUS
5013 && REG_P (XEXP (XEXP (tem, 0), 0))
5014 && GET_CODE (XEXP (XEXP (tem, 0), 1)) == CONST_INT)))
5016 /* Must use TEM here, not AD, since it is the one that will
5017 have any subexpressions reloaded, if needed. */
5018 push_reload (tem, NULL_RTX, loc, (rtx*) 0,
5019 base_reg_class (mode, MEM, SCRATCH), GET_MODE (tem),
5020 VOIDmode, 0,
5021 0, opnum, type);
5022 return ! removed_and;
5024 else
5025 return 0;
5028 /* If we have address of a stack slot but it's not valid because the
5029 displacement is too large, compute the sum in a register.
5030 Handle all base registers here, not just fp/ap/sp, because on some
5031 targets (namely SH) we can also get too large displacements from
5032 big-endian corrections. */
5033 else if (GET_CODE (ad) == PLUS
5034 && REG_P (XEXP (ad, 0))
5035 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
5036 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5037 && regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, PLUS,
5038 CONST_INT))
5041 /* Unshare the MEM rtx so we can safely alter it. */
5042 if (memrefloc)
5044 *memrefloc = copy_rtx (*memrefloc);
5045 loc = &XEXP (*memrefloc, 0);
5046 if (removed_and)
5047 loc = &XEXP (*loc, 0);
5050 if (double_reg_address_ok)
5052 /* Unshare the sum as well. */
5053 *loc = ad = copy_rtx (ad);
5055 /* Reload the displacement into an index reg.
5056 We assume the frame pointer or arg pointer is a base reg. */
5057 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
5058 INDEX_REG_CLASS, GET_MODE (ad), opnum,
5059 type, ind_levels);
5060 return 0;
5062 else
5064 /* If the sum of two regs is not necessarily valid,
5065 reload the sum into a base reg.
5066 That will at least work. */
5067 find_reloads_address_part (ad, loc,
5068 base_reg_class (mode, MEM, SCRATCH),
5069 Pmode, opnum, type, ind_levels);
5071 return ! removed_and;
5074 /* If we have an indexed stack slot, there are three possible reasons why
5075 it might be invalid: The index might need to be reloaded, the address
5076 might have been made by frame pointer elimination and hence have a
5077 constant out of range, or both reasons might apply.
5079 We can easily check for an index needing reload, but even if that is the
5080 case, we might also have an invalid constant. To avoid making the
5081 conservative assumption and requiring two reloads, we see if this address
5082 is valid when not interpreted strictly. If it is, the only problem is
5083 that the index needs a reload and find_reloads_address_1 will take care
5084 of it.
5086 Handle all base registers here, not just fp/ap/sp, because on some
5087 targets (namely SPARC) we can also get invalid addresses from preventive
5088 subreg big-endian corrections made by find_reloads_toplev. We
5089 can also get expressions involving LO_SUM (rather than PLUS) from
5090 find_reloads_subreg_address.
5092 If we decide to do something, it must be that `double_reg_address_ok'
5093 is true. We generate a reload of the base register + constant and
5094 rework the sum so that the reload register will be added to the index.
5095 This is safe because we know the address isn't shared.
5097 We check for the base register as both the first and second operand of
5098 the innermost PLUS and/or LO_SUM. */
5100 for (op_index = 0; op_index < 2; ++op_index)
5102 rtx operand, addend;
5103 enum rtx_code inner_code;
5105 if (GET_CODE (ad) != PLUS)
5106 continue;
5108 inner_code = GET_CODE (XEXP (ad, 0));
5109 if (!(GET_CODE (ad) == PLUS
5110 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5111 && (inner_code == PLUS || inner_code == LO_SUM)))
5112 continue;
5114 operand = XEXP (XEXP (ad, 0), op_index);
5115 if (!REG_P (operand) || REGNO (operand) >= FIRST_PSEUDO_REGISTER)
5116 continue;
5118 addend = XEXP (XEXP (ad, 0), 1 - op_index);
5120 if ((regno_ok_for_base_p (REGNO (operand), mode, inner_code,
5121 GET_CODE (addend))
5122 || operand == frame_pointer_rtx
5123 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
5124 || operand == hard_frame_pointer_rtx
5125 #endif
5126 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5127 || operand == arg_pointer_rtx
5128 #endif
5129 || operand == stack_pointer_rtx)
5130 && ! maybe_memory_address_p (mode, ad,
5131 &XEXP (XEXP (ad, 0), 1 - op_index)))
5133 rtx offset_reg;
5134 enum reg_class cls;
5136 offset_reg = plus_constant (operand, INTVAL (XEXP (ad, 1)));
5138 /* Form the adjusted address. */
5139 if (GET_CODE (XEXP (ad, 0)) == PLUS)
5140 ad = gen_rtx_PLUS (GET_MODE (ad),
5141 op_index == 0 ? offset_reg : addend,
5142 op_index == 0 ? addend : offset_reg);
5143 else
5144 ad = gen_rtx_LO_SUM (GET_MODE (ad),
5145 op_index == 0 ? offset_reg : addend,
5146 op_index == 0 ? addend : offset_reg);
5147 *loc = ad;
5149 cls = base_reg_class (mode, MEM, GET_CODE (addend));
5150 find_reloads_address_part (XEXP (ad, op_index),
5151 &XEXP (ad, op_index), cls,
5152 GET_MODE (ad), opnum, type, ind_levels);
5153 find_reloads_address_1 (mode,
5154 XEXP (ad, 1 - op_index), 1, GET_CODE (ad),
5155 GET_CODE (XEXP (ad, op_index)),
5156 &XEXP (ad, 1 - op_index), opnum,
5157 type, 0, insn);
5159 return 0;
5163 /* See if address becomes valid when an eliminable register
5164 in a sum is replaced. */
5166 tem = ad;
5167 if (GET_CODE (ad) == PLUS)
5168 tem = subst_indexed_address (ad);
5169 if (tem != ad && strict_memory_address_p (mode, tem))
5171 /* Ok, we win that way. Replace any additional eliminable
5172 registers. */
5174 subst_reg_equivs_changed = 0;
5175 tem = subst_reg_equivs (tem, insn);
5177 /* Make sure that didn't make the address invalid again. */
5179 if (! subst_reg_equivs_changed || strict_memory_address_p (mode, tem))
5181 *loc = tem;
5182 return 0;
5186 /* If constants aren't valid addresses, reload the constant address
5187 into a register. */
5188 if (CONSTANT_P (ad) && ! strict_memory_address_p (mode, ad))
5190 /* If AD is an address in the constant pool, the MEM rtx may be shared.
5191 Unshare it so we can safely alter it. */
5192 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
5193 && CONSTANT_POOL_ADDRESS_P (ad))
5195 *memrefloc = copy_rtx (*memrefloc);
5196 loc = &XEXP (*memrefloc, 0);
5197 if (removed_and)
5198 loc = &XEXP (*loc, 0);
5201 find_reloads_address_part (ad, loc, base_reg_class (mode, MEM, SCRATCH),
5202 Pmode, opnum, type, ind_levels);
5203 return ! removed_and;
5206 return find_reloads_address_1 (mode, ad, 0, MEM, SCRATCH, loc, opnum, type,
5207 ind_levels, insn);
5210 /* Find all pseudo regs appearing in AD
5211 that are eliminable in favor of equivalent values
5212 and do not have hard regs; replace them by their equivalents.
5213 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
5214 front of it for pseudos that we have to replace with stack slots. */
5216 static rtx
5217 subst_reg_equivs (rtx ad, rtx insn)
5219 RTX_CODE code = GET_CODE (ad);
5220 int i;
5221 const char *fmt;
5223 switch (code)
5225 case HIGH:
5226 case CONST_INT:
5227 case CONST:
5228 case CONST_DOUBLE:
5229 case CONST_FIXED:
5230 case CONST_VECTOR:
5231 case SYMBOL_REF:
5232 case LABEL_REF:
5233 case PC:
5234 case CC0:
5235 return ad;
5237 case REG:
5239 int regno = REGNO (ad);
5241 if (reg_equiv_constant[regno] != 0)
5243 subst_reg_equivs_changed = 1;
5244 return reg_equiv_constant[regno];
5246 if (reg_equiv_memory_loc[regno] && num_not_at_initial_offset)
5248 rtx mem = make_memloc (ad, regno);
5249 if (! rtx_equal_p (mem, reg_equiv_mem[regno]))
5251 subst_reg_equivs_changed = 1;
5252 /* We mark the USE with QImode so that we recognize it
5253 as one that can be safely deleted at the end of
5254 reload. */
5255 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn),
5256 QImode);
5257 return mem;
5261 return ad;
5263 case PLUS:
5264 /* Quickly dispose of a common case. */
5265 if (XEXP (ad, 0) == frame_pointer_rtx
5266 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
5267 return ad;
5268 break;
5270 default:
5271 break;
5274 fmt = GET_RTX_FORMAT (code);
5275 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5276 if (fmt[i] == 'e')
5277 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
5278 return ad;
5281 /* Compute the sum of X and Y, making canonicalizations assumed in an
5282 address, namely: sum constant integers, surround the sum of two
5283 constants with a CONST, put the constant as the second operand, and
5284 group the constant on the outermost sum.
5286 This routine assumes both inputs are already in canonical form. */
5289 form_sum (rtx x, rtx y)
5291 rtx tem;
5292 enum machine_mode mode = GET_MODE (x);
5294 if (mode == VOIDmode)
5295 mode = GET_MODE (y);
5297 if (mode == VOIDmode)
5298 mode = Pmode;
5300 if (GET_CODE (x) == CONST_INT)
5301 return plus_constant (y, INTVAL (x));
5302 else if (GET_CODE (y) == CONST_INT)
5303 return plus_constant (x, INTVAL (y));
5304 else if (CONSTANT_P (x))
5305 tem = x, x = y, y = tem;
5307 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
5308 return form_sum (XEXP (x, 0), form_sum (XEXP (x, 1), y));
5310 /* Note that if the operands of Y are specified in the opposite
5311 order in the recursive calls below, infinite recursion will occur. */
5312 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
5313 return form_sum (form_sum (x, XEXP (y, 0)), XEXP (y, 1));
5315 /* If both constant, encapsulate sum. Otherwise, just form sum. A
5316 constant will have been placed second. */
5317 if (CONSTANT_P (x) && CONSTANT_P (y))
5319 if (GET_CODE (x) == CONST)
5320 x = XEXP (x, 0);
5321 if (GET_CODE (y) == CONST)
5322 y = XEXP (y, 0);
5324 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
5327 return gen_rtx_PLUS (mode, x, y);
5330 /* If ADDR is a sum containing a pseudo register that should be
5331 replaced with a constant (from reg_equiv_constant),
5332 return the result of doing so, and also apply the associative
5333 law so that the result is more likely to be a valid address.
5334 (But it is not guaranteed to be one.)
5336 Note that at most one register is replaced, even if more are
5337 replaceable. Also, we try to put the result into a canonical form
5338 so it is more likely to be a valid address.
5340 In all other cases, return ADDR. */
5342 static rtx
5343 subst_indexed_address (rtx addr)
5345 rtx op0 = 0, op1 = 0, op2 = 0;
5346 rtx tem;
5347 int regno;
5349 if (GET_CODE (addr) == PLUS)
5351 /* Try to find a register to replace. */
5352 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
5353 if (REG_P (op0)
5354 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
5355 && reg_renumber[regno] < 0
5356 && reg_equiv_constant[regno] != 0)
5357 op0 = reg_equiv_constant[regno];
5358 else if (REG_P (op1)
5359 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
5360 && reg_renumber[regno] < 0
5361 && reg_equiv_constant[regno] != 0)
5362 op1 = reg_equiv_constant[regno];
5363 else if (GET_CODE (op0) == PLUS
5364 && (tem = subst_indexed_address (op0)) != op0)
5365 op0 = tem;
5366 else if (GET_CODE (op1) == PLUS
5367 && (tem = subst_indexed_address (op1)) != op1)
5368 op1 = tem;
5369 else
5370 return addr;
5372 /* Pick out up to three things to add. */
5373 if (GET_CODE (op1) == PLUS)
5374 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
5375 else if (GET_CODE (op0) == PLUS)
5376 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
5378 /* Compute the sum. */
5379 if (op2 != 0)
5380 op1 = form_sum (op1, op2);
5381 if (op1 != 0)
5382 op0 = form_sum (op0, op1);
5384 return op0;
5386 return addr;
5389 /* Update the REG_INC notes for an insn. It updates all REG_INC
5390 notes for the instruction which refer to REGNO the to refer
5391 to the reload number.
5393 INSN is the insn for which any REG_INC notes need updating.
5395 REGNO is the register number which has been reloaded.
5397 RELOADNUM is the reload number. */
5399 static void
5400 update_auto_inc_notes (rtx insn ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED,
5401 int reloadnum ATTRIBUTE_UNUSED)
5403 #ifdef AUTO_INC_DEC
5404 rtx link;
5406 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
5407 if (REG_NOTE_KIND (link) == REG_INC
5408 && (int) REGNO (XEXP (link, 0)) == regno)
5409 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5410 #endif
5413 /* Record the pseudo registers we must reload into hard registers in a
5414 subexpression of a would-be memory address, X referring to a value
5415 in mode MODE. (This function is not called if the address we find
5416 is strictly valid.)
5418 CONTEXT = 1 means we are considering regs as index regs,
5419 = 0 means we are considering them as base regs.
5420 OUTER_CODE is the code of the enclosing RTX, typically a MEM, a PLUS,
5421 or an autoinc code.
5422 If CONTEXT == 0 and OUTER_CODE is a PLUS or LO_SUM, then INDEX_CODE
5423 is the code of the index part of the address. Otherwise, pass SCRATCH
5424 for this argument.
5425 OPNUM and TYPE specify the purpose of any reloads made.
5427 IND_LEVELS says how many levels of indirect addressing are
5428 supported at this point in the address.
5430 INSN, if nonzero, is the insn in which we do the reload. It is used
5431 to determine if we may generate output reloads.
5433 We return nonzero if X, as a whole, is reloaded or replaced. */
5435 /* Note that we take shortcuts assuming that no multi-reg machine mode
5436 occurs as part of an address.
5437 Also, this is not fully machine-customizable; it works for machines
5438 such as VAXen and 68000's and 32000's, but other possible machines
5439 could have addressing modes that this does not handle right.
5440 If you add push_reload calls here, you need to make sure gen_reload
5441 handles those cases gracefully. */
5443 static int
5444 find_reloads_address_1 (enum machine_mode mode, rtx x, int context,
5445 enum rtx_code outer_code, enum rtx_code index_code,
5446 rtx *loc, int opnum, enum reload_type type,
5447 int ind_levels, rtx insn)
5449 #define REG_OK_FOR_CONTEXT(CONTEXT, REGNO, MODE, OUTER, INDEX) \
5450 ((CONTEXT) == 0 \
5451 ? regno_ok_for_base_p (REGNO, MODE, OUTER, INDEX) \
5452 : REGNO_OK_FOR_INDEX_P (REGNO))
5454 enum reg_class context_reg_class;
5455 RTX_CODE code = GET_CODE (x);
5457 if (context == 1)
5458 context_reg_class = INDEX_REG_CLASS;
5459 else
5460 context_reg_class = base_reg_class (mode, outer_code, index_code);
5462 switch (code)
5464 case PLUS:
5466 rtx orig_op0 = XEXP (x, 0);
5467 rtx orig_op1 = XEXP (x, 1);
5468 RTX_CODE code0 = GET_CODE (orig_op0);
5469 RTX_CODE code1 = GET_CODE (orig_op1);
5470 rtx op0 = orig_op0;
5471 rtx op1 = orig_op1;
5473 if (GET_CODE (op0) == SUBREG)
5475 op0 = SUBREG_REG (op0);
5476 code0 = GET_CODE (op0);
5477 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5478 op0 = gen_rtx_REG (word_mode,
5479 (REGNO (op0) +
5480 subreg_regno_offset (REGNO (SUBREG_REG (orig_op0)),
5481 GET_MODE (SUBREG_REG (orig_op0)),
5482 SUBREG_BYTE (orig_op0),
5483 GET_MODE (orig_op0))));
5486 if (GET_CODE (op1) == SUBREG)
5488 op1 = SUBREG_REG (op1);
5489 code1 = GET_CODE (op1);
5490 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5491 /* ??? Why is this given op1's mode and above for
5492 ??? op0 SUBREGs we use word_mode? */
5493 op1 = gen_rtx_REG (GET_MODE (op1),
5494 (REGNO (op1) +
5495 subreg_regno_offset (REGNO (SUBREG_REG (orig_op1)),
5496 GET_MODE (SUBREG_REG (orig_op1)),
5497 SUBREG_BYTE (orig_op1),
5498 GET_MODE (orig_op1))));
5500 /* Plus in the index register may be created only as a result of
5501 register rematerialization for expression like &localvar*4. Reload it.
5502 It may be possible to combine the displacement on the outer level,
5503 but it is probably not worthwhile to do so. */
5504 if (context == 1)
5506 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5507 opnum, ADDR_TYPE (type), ind_levels, insn);
5508 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5509 context_reg_class,
5510 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5511 return 1;
5514 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
5515 || code0 == ZERO_EXTEND || code1 == MEM)
5517 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5518 &XEXP (x, 0), opnum, type, ind_levels,
5519 insn);
5520 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5521 &XEXP (x, 1), opnum, type, ind_levels,
5522 insn);
5525 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
5526 || code1 == ZERO_EXTEND || code0 == MEM)
5528 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5529 &XEXP (x, 0), opnum, type, ind_levels,
5530 insn);
5531 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5532 &XEXP (x, 1), opnum, type, ind_levels,
5533 insn);
5536 else if (code0 == CONST_INT || code0 == CONST
5537 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5538 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5539 &XEXP (x, 1), opnum, type, ind_levels,
5540 insn);
5542 else if (code1 == CONST_INT || code1 == CONST
5543 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5544 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5545 &XEXP (x, 0), opnum, type, ind_levels,
5546 insn);
5548 else if (code0 == REG && code1 == REG)
5550 if (REGNO_OK_FOR_INDEX_P (REGNO (op1))
5551 && regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5552 return 0;
5553 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0))
5554 && regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5555 return 0;
5556 else if (regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5557 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5558 &XEXP (x, 1), opnum, type, ind_levels,
5559 insn);
5560 else if (REGNO_OK_FOR_INDEX_P (REGNO (op1)))
5561 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5562 &XEXP (x, 0), opnum, type, ind_levels,
5563 insn);
5564 else if (regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5565 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5566 &XEXP (x, 0), opnum, type, ind_levels,
5567 insn);
5568 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0)))
5569 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5570 &XEXP (x, 1), opnum, type, ind_levels,
5571 insn);
5572 else
5574 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5575 &XEXP (x, 0), opnum, type, ind_levels,
5576 insn);
5577 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5578 &XEXP (x, 1), opnum, type, ind_levels,
5579 insn);
5583 else if (code0 == REG)
5585 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5586 &XEXP (x, 0), opnum, type, ind_levels,
5587 insn);
5588 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5589 &XEXP (x, 1), opnum, type, ind_levels,
5590 insn);
5593 else if (code1 == REG)
5595 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5596 &XEXP (x, 1), opnum, type, ind_levels,
5597 insn);
5598 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5599 &XEXP (x, 0), opnum, type, ind_levels,
5600 insn);
5604 return 0;
5606 case POST_MODIFY:
5607 case PRE_MODIFY:
5609 rtx op0 = XEXP (x, 0);
5610 rtx op1 = XEXP (x, 1);
5611 enum rtx_code index_code;
5612 int regno;
5613 int reloadnum;
5615 if (GET_CODE (op1) != PLUS && GET_CODE (op1) != MINUS)
5616 return 0;
5618 /* Currently, we only support {PRE,POST}_MODIFY constructs
5619 where a base register is {inc,dec}remented by the contents
5620 of another register or by a constant value. Thus, these
5621 operands must match. */
5622 gcc_assert (op0 == XEXP (op1, 0));
5624 /* Require index register (or constant). Let's just handle the
5625 register case in the meantime... If the target allows
5626 auto-modify by a constant then we could try replacing a pseudo
5627 register with its equivalent constant where applicable.
5629 We also handle the case where the register was eliminated
5630 resulting in a PLUS subexpression.
5632 If we later decide to reload the whole PRE_MODIFY or
5633 POST_MODIFY, inc_for_reload might clobber the reload register
5634 before reading the index. The index register might therefore
5635 need to live longer than a TYPE reload normally would, so be
5636 conservative and class it as RELOAD_OTHER. */
5637 if ((REG_P (XEXP (op1, 1))
5638 && !REGNO_OK_FOR_INDEX_P (REGNO (XEXP (op1, 1))))
5639 || GET_CODE (XEXP (op1, 1)) == PLUS)
5640 find_reloads_address_1 (mode, XEXP (op1, 1), 1, code, SCRATCH,
5641 &XEXP (op1, 1), opnum, RELOAD_OTHER,
5642 ind_levels, insn);
5644 gcc_assert (REG_P (XEXP (op1, 0)));
5646 regno = REGNO (XEXP (op1, 0));
5647 index_code = GET_CODE (XEXP (op1, 1));
5649 /* A register that is incremented cannot be constant! */
5650 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5651 || reg_equiv_constant[regno] == 0);
5653 /* Handle a register that is equivalent to a memory location
5654 which cannot be addressed directly. */
5655 if (reg_equiv_memory_loc[regno] != 0
5656 && (reg_equiv_address[regno] != 0
5657 || num_not_at_initial_offset))
5659 rtx tem = make_memloc (XEXP (x, 0), regno);
5661 if (reg_equiv_address[regno]
5662 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5664 rtx orig = tem;
5666 /* First reload the memory location's address.
5667 We can't use ADDR_TYPE (type) here, because we need to
5668 write back the value after reading it, hence we actually
5669 need two registers. */
5670 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5671 &XEXP (tem, 0), opnum,
5672 RELOAD_OTHER,
5673 ind_levels, insn);
5675 if (!rtx_equal_p (tem, orig))
5676 push_reg_equiv_alt_mem (regno, tem);
5678 /* Then reload the memory location into a base
5679 register. */
5680 reloadnum = push_reload (tem, tem, &XEXP (x, 0),
5681 &XEXP (op1, 0),
5682 base_reg_class (mode, code,
5683 index_code),
5684 GET_MODE (x), GET_MODE (x), 0,
5685 0, opnum, RELOAD_OTHER);
5687 update_auto_inc_notes (this_insn, regno, reloadnum);
5688 return 0;
5692 if (reg_renumber[regno] >= 0)
5693 regno = reg_renumber[regno];
5695 /* We require a base register here... */
5696 if (!regno_ok_for_base_p (regno, GET_MODE (x), code, index_code))
5698 reloadnum = push_reload (XEXP (op1, 0), XEXP (x, 0),
5699 &XEXP (op1, 0), &XEXP (x, 0),
5700 base_reg_class (mode, code, index_code),
5701 GET_MODE (x), GET_MODE (x), 0, 0,
5702 opnum, RELOAD_OTHER);
5704 update_auto_inc_notes (this_insn, regno, reloadnum);
5705 return 0;
5708 return 0;
5710 case POST_INC:
5711 case POST_DEC:
5712 case PRE_INC:
5713 case PRE_DEC:
5714 if (REG_P (XEXP (x, 0)))
5716 int regno = REGNO (XEXP (x, 0));
5717 int value = 0;
5718 rtx x_orig = x;
5720 /* A register that is incremented cannot be constant! */
5721 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5722 || reg_equiv_constant[regno] == 0);
5724 /* Handle a register that is equivalent to a memory location
5725 which cannot be addressed directly. */
5726 if (reg_equiv_memory_loc[regno] != 0
5727 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5729 rtx tem = make_memloc (XEXP (x, 0), regno);
5730 if (reg_equiv_address[regno]
5731 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5733 rtx orig = tem;
5735 /* First reload the memory location's address.
5736 We can't use ADDR_TYPE (type) here, because we need to
5737 write back the value after reading it, hence we actually
5738 need two registers. */
5739 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5740 &XEXP (tem, 0), opnum, type,
5741 ind_levels, insn);
5742 if (!rtx_equal_p (tem, orig))
5743 push_reg_equiv_alt_mem (regno, tem);
5744 /* Put this inside a new increment-expression. */
5745 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5746 /* Proceed to reload that, as if it contained a register. */
5750 /* If we have a hard register that is ok in this incdec context,
5751 don't make a reload. If the register isn't nice enough for
5752 autoincdec, we can reload it. But, if an autoincrement of a
5753 register that we here verified as playing nice, still outside
5754 isn't "valid", it must be that no autoincrement is "valid".
5755 If that is true and something made an autoincrement anyway,
5756 this must be a special context where one is allowed.
5757 (For example, a "push" instruction.)
5758 We can't improve this address, so leave it alone. */
5760 /* Otherwise, reload the autoincrement into a suitable hard reg
5761 and record how much to increment by. */
5763 if (reg_renumber[regno] >= 0)
5764 regno = reg_renumber[regno];
5765 if (regno >= FIRST_PSEUDO_REGISTER
5766 || !REG_OK_FOR_CONTEXT (context, regno, mode, code,
5767 index_code))
5769 int reloadnum;
5771 /* If we can output the register afterwards, do so, this
5772 saves the extra update.
5773 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5774 CALL_INSN - and it does not set CC0.
5775 But don't do this if we cannot directly address the
5776 memory location, since this will make it harder to
5777 reuse address reloads, and increases register pressure.
5778 Also don't do this if we can probably update x directly. */
5779 rtx equiv = (MEM_P (XEXP (x, 0))
5780 ? XEXP (x, 0)
5781 : reg_equiv_mem[regno]);
5782 int icode = (int) optab_handler (add_optab, Pmode)->insn_code;
5783 if (insn && NONJUMP_INSN_P (insn) && equiv
5784 && memory_operand (equiv, GET_MODE (equiv))
5785 #ifdef HAVE_cc0
5786 && ! sets_cc0_p (PATTERN (insn))
5787 #endif
5788 && ! (icode != CODE_FOR_nothing
5789 && ((*insn_data[icode].operand[0].predicate)
5790 (equiv, Pmode))
5791 && ((*insn_data[icode].operand[1].predicate)
5792 (equiv, Pmode))))
5794 /* We use the original pseudo for loc, so that
5795 emit_reload_insns() knows which pseudo this
5796 reload refers to and updates the pseudo rtx, not
5797 its equivalent memory location, as well as the
5798 corresponding entry in reg_last_reload_reg. */
5799 loc = &XEXP (x_orig, 0);
5800 x = XEXP (x, 0);
5801 reloadnum
5802 = push_reload (x, x, loc, loc,
5803 context_reg_class,
5804 GET_MODE (x), GET_MODE (x), 0, 0,
5805 opnum, RELOAD_OTHER);
5807 else
5809 reloadnum
5810 = push_reload (x, x, loc, (rtx*) 0,
5811 context_reg_class,
5812 GET_MODE (x), GET_MODE (x), 0, 0,
5813 opnum, type);
5814 rld[reloadnum].inc
5815 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5817 value = 1;
5820 update_auto_inc_notes (this_insn, REGNO (XEXP (x_orig, 0)),
5821 reloadnum);
5823 return value;
5825 return 0;
5827 case TRUNCATE:
5828 case SIGN_EXTEND:
5829 case ZERO_EXTEND:
5830 /* Look for parts to reload in the inner expression and reload them
5831 too, in addition to this operation. Reloading all inner parts in
5832 addition to this one shouldn't be necessary, but at this point,
5833 we don't know if we can possibly omit any part that *can* be
5834 reloaded. Targets that are better off reloading just either part
5835 (or perhaps even a different part of an outer expression), should
5836 define LEGITIMIZE_RELOAD_ADDRESS. */
5837 find_reloads_address_1 (GET_MODE (XEXP (x, 0)), XEXP (x, 0),
5838 context, code, SCRATCH, &XEXP (x, 0), opnum,
5839 type, ind_levels, insn);
5840 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5841 context_reg_class,
5842 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5843 return 1;
5845 case MEM:
5846 /* This is probably the result of a substitution, by eliminate_regs, of
5847 an equivalent address for a pseudo that was not allocated to a hard
5848 register. Verify that the specified address is valid and reload it
5849 into a register.
5851 Since we know we are going to reload this item, don't decrement for
5852 the indirection level.
5854 Note that this is actually conservative: it would be slightly more
5855 efficient to use the value of SPILL_INDIRECT_LEVELS from
5856 reload1.c here. */
5858 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5859 opnum, ADDR_TYPE (type), ind_levels, insn);
5860 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5861 context_reg_class,
5862 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5863 return 1;
5865 case REG:
5867 int regno = REGNO (x);
5869 if (reg_equiv_constant[regno] != 0)
5871 find_reloads_address_part (reg_equiv_constant[regno], loc,
5872 context_reg_class,
5873 GET_MODE (x), opnum, type, ind_levels);
5874 return 1;
5877 #if 0 /* This might screw code in reload1.c to delete prior output-reload
5878 that feeds this insn. */
5879 if (reg_equiv_mem[regno] != 0)
5881 push_reload (reg_equiv_mem[regno], NULL_RTX, loc, (rtx*) 0,
5882 context_reg_class,
5883 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5884 return 1;
5886 #endif
5888 if (reg_equiv_memory_loc[regno]
5889 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5891 rtx tem = make_memloc (x, regno);
5892 if (reg_equiv_address[regno] != 0
5893 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5895 x = tem;
5896 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5897 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5898 ind_levels, insn);
5899 if (!rtx_equal_p (x, tem))
5900 push_reg_equiv_alt_mem (regno, x);
5904 if (reg_renumber[regno] >= 0)
5905 regno = reg_renumber[regno];
5907 if (regno >= FIRST_PSEUDO_REGISTER
5908 || !REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5909 index_code))
5911 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5912 context_reg_class,
5913 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5914 return 1;
5917 /* If a register appearing in an address is the subject of a CLOBBER
5918 in this insn, reload it into some other register to be safe.
5919 The CLOBBER is supposed to make the register unavailable
5920 from before this insn to after it. */
5921 if (regno_clobbered_p (regno, this_insn, GET_MODE (x), 0))
5923 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5924 context_reg_class,
5925 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5926 return 1;
5929 return 0;
5931 case SUBREG:
5932 if (REG_P (SUBREG_REG (x)))
5934 /* If this is a SUBREG of a hard register and the resulting register
5935 is of the wrong class, reload the whole SUBREG. This avoids
5936 needless copies if SUBREG_REG is multi-word. */
5937 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5939 int regno ATTRIBUTE_UNUSED = subreg_regno (x);
5941 if (!REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5942 index_code))
5944 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5945 context_reg_class,
5946 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5947 return 1;
5950 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
5951 is larger than the class size, then reload the whole SUBREG. */
5952 else
5954 enum reg_class rclass = context_reg_class;
5955 if ((unsigned) CLASS_MAX_NREGS (rclass, GET_MODE (SUBREG_REG (x)))
5956 > reg_class_size[rclass])
5958 x = find_reloads_subreg_address (x, 0, opnum,
5959 ADDR_TYPE (type),
5960 ind_levels, insn);
5961 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
5962 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5963 return 1;
5967 break;
5969 default:
5970 break;
5974 const char *fmt = GET_RTX_FORMAT (code);
5975 int i;
5977 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5979 if (fmt[i] == 'e')
5980 /* Pass SCRATCH for INDEX_CODE, since CODE can never be a PLUS once
5981 we get here. */
5982 find_reloads_address_1 (mode, XEXP (x, i), context, code, SCRATCH,
5983 &XEXP (x, i), opnum, type, ind_levels, insn);
5987 #undef REG_OK_FOR_CONTEXT
5988 return 0;
5991 /* X, which is found at *LOC, is a part of an address that needs to be
5992 reloaded into a register of class RCLASS. If X is a constant, or if
5993 X is a PLUS that contains a constant, check that the constant is a
5994 legitimate operand and that we are supposed to be able to load
5995 it into the register.
5997 If not, force the constant into memory and reload the MEM instead.
5999 MODE is the mode to use, in case X is an integer constant.
6001 OPNUM and TYPE describe the purpose of any reloads made.
6003 IND_LEVELS says how many levels of indirect addressing this machine
6004 supports. */
6006 static void
6007 find_reloads_address_part (rtx x, rtx *loc, enum reg_class rclass,
6008 enum machine_mode mode, int opnum,
6009 enum reload_type type, int ind_levels)
6011 if (CONSTANT_P (x)
6012 && (! LEGITIMATE_CONSTANT_P (x)
6013 || PREFERRED_RELOAD_CLASS (x, rclass) == NO_REGS))
6015 x = force_const_mem (mode, x);
6016 find_reloads_address (mode, &x, XEXP (x, 0), &XEXP (x, 0),
6017 opnum, type, ind_levels, 0);
6020 else if (GET_CODE (x) == PLUS
6021 && CONSTANT_P (XEXP (x, 1))
6022 && (! LEGITIMATE_CONSTANT_P (XEXP (x, 1))
6023 || PREFERRED_RELOAD_CLASS (XEXP (x, 1), rclass) == NO_REGS))
6025 rtx tem;
6027 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
6028 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
6029 find_reloads_address (mode, &XEXP (x, 1), XEXP (tem, 0), &XEXP (tem, 0),
6030 opnum, type, ind_levels, 0);
6033 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6034 mode, VOIDmode, 0, 0, opnum, type);
6037 /* X, a subreg of a pseudo, is a part of an address that needs to be
6038 reloaded.
6040 If the pseudo is equivalent to a memory location that cannot be directly
6041 addressed, make the necessary address reloads.
6043 If address reloads have been necessary, or if the address is changed
6044 by register elimination, return the rtx of the memory location;
6045 otherwise, return X.
6047 If FORCE_REPLACE is nonzero, unconditionally replace the subreg with the
6048 memory location.
6050 OPNUM and TYPE identify the purpose of the reload.
6052 IND_LEVELS says how many levels of indirect addressing are
6053 supported at this point in the address.
6055 INSN, if nonzero, is the insn in which we do the reload. It is used
6056 to determine where to put USEs for pseudos that we have to replace with
6057 stack slots. */
6059 static rtx
6060 find_reloads_subreg_address (rtx x, int force_replace, int opnum,
6061 enum reload_type type, int ind_levels, rtx insn)
6063 int regno = REGNO (SUBREG_REG (x));
6065 if (reg_equiv_memory_loc[regno])
6067 /* If the address is not directly addressable, or if the address is not
6068 offsettable, then it must be replaced. */
6069 if (! force_replace
6070 && (reg_equiv_address[regno]
6071 || ! offsettable_memref_p (reg_equiv_mem[regno])))
6072 force_replace = 1;
6074 if (force_replace || num_not_at_initial_offset)
6076 rtx tem = make_memloc (SUBREG_REG (x), regno);
6078 /* If the address changes because of register elimination, then
6079 it must be replaced. */
6080 if (force_replace
6081 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
6083 unsigned outer_size = GET_MODE_SIZE (GET_MODE (x));
6084 unsigned inner_size = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
6085 int offset;
6086 rtx orig = tem;
6087 int reloaded;
6089 /* For big-endian paradoxical subregs, SUBREG_BYTE does not
6090 hold the correct (negative) byte offset. */
6091 if (BYTES_BIG_ENDIAN && outer_size > inner_size)
6092 offset = inner_size - outer_size;
6093 else
6094 offset = SUBREG_BYTE (x);
6096 XEXP (tem, 0) = plus_constant (XEXP (tem, 0), offset);
6097 PUT_MODE (tem, GET_MODE (x));
6098 if (MEM_OFFSET (tem))
6099 set_mem_offset (tem, plus_constant (MEM_OFFSET (tem), offset));
6101 /* If this was a paradoxical subreg that we replaced, the
6102 resulting memory must be sufficiently aligned to allow
6103 us to widen the mode of the memory. */
6104 if (outer_size > inner_size)
6106 rtx base;
6108 base = XEXP (tem, 0);
6109 if (GET_CODE (base) == PLUS)
6111 if (GET_CODE (XEXP (base, 1)) == CONST_INT
6112 && INTVAL (XEXP (base, 1)) % outer_size != 0)
6113 return x;
6114 base = XEXP (base, 0);
6116 if (!REG_P (base)
6117 || (REGNO_POINTER_ALIGN (REGNO (base))
6118 < outer_size * BITS_PER_UNIT))
6119 return x;
6122 reloaded = find_reloads_address (GET_MODE (tem), &tem,
6123 XEXP (tem, 0), &XEXP (tem, 0),
6124 opnum, type, ind_levels, insn);
6125 /* ??? Do we need to handle nonzero offsets somehow? */
6126 if (!offset && !rtx_equal_p (tem, orig))
6127 push_reg_equiv_alt_mem (regno, tem);
6129 /* For some processors an address may be valid in the
6130 original mode but not in a smaller mode. For
6131 example, ARM accepts a scaled index register in
6132 SImode but not in HImode. Similarly, the address may
6133 have been valid before the subreg offset was added,
6134 but not afterwards. find_reloads_address
6135 assumes that we pass it a valid address, and doesn't
6136 force a reload. This will probably be fine if
6137 find_reloads_address finds some reloads. But if it
6138 doesn't find any, then we may have just converted a
6139 valid address into an invalid one. Check for that
6140 here. */
6141 if (reloaded == 0
6142 && !strict_memory_address_p (GET_MODE (tem),
6143 XEXP (tem, 0)))
6144 push_reload (XEXP (tem, 0), NULL_RTX, &XEXP (tem, 0), (rtx*) 0,
6145 base_reg_class (GET_MODE (tem), MEM, SCRATCH),
6146 GET_MODE (XEXP (tem, 0)), VOIDmode, 0, 0,
6147 opnum, type);
6149 /* If this is not a toplevel operand, find_reloads doesn't see
6150 this substitution. We have to emit a USE of the pseudo so
6151 that delete_output_reload can see it. */
6152 if (replace_reloads && recog_data.operand[opnum] != x)
6153 /* We mark the USE with QImode so that we recognize it
6154 as one that can be safely deleted at the end of
6155 reload. */
6156 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode,
6157 SUBREG_REG (x)),
6158 insn), QImode);
6159 x = tem;
6163 return x;
6166 /* Substitute into the current INSN the registers into which we have reloaded
6167 the things that need reloading. The array `replacements'
6168 contains the locations of all pointers that must be changed
6169 and says what to replace them with.
6171 Return the rtx that X translates into; usually X, but modified. */
6173 void
6174 subst_reloads (rtx insn)
6176 int i;
6178 for (i = 0; i < n_replacements; i++)
6180 struct replacement *r = &replacements[i];
6181 rtx reloadreg = rld[r->what].reg_rtx;
6182 if (reloadreg)
6184 #ifdef DEBUG_RELOAD
6185 /* This checking takes a very long time on some platforms
6186 causing the gcc.c-torture/compile/limits-fnargs.c test
6187 to time out during testing. See PR 31850.
6189 Internal consistency test. Check that we don't modify
6190 anything in the equivalence arrays. Whenever something from
6191 those arrays needs to be reloaded, it must be unshared before
6192 being substituted into; the equivalence must not be modified.
6193 Otherwise, if the equivalence is used after that, it will
6194 have been modified, and the thing substituted (probably a
6195 register) is likely overwritten and not a usable equivalence. */
6196 int check_regno;
6198 for (check_regno = 0; check_regno < max_regno; check_regno++)
6200 #define CHECK_MODF(ARRAY) \
6201 gcc_assert (!ARRAY[check_regno] \
6202 || !loc_mentioned_in_p (r->where, \
6203 ARRAY[check_regno]))
6205 CHECK_MODF (reg_equiv_constant);
6206 CHECK_MODF (reg_equiv_memory_loc);
6207 CHECK_MODF (reg_equiv_address);
6208 CHECK_MODF (reg_equiv_mem);
6209 #undef CHECK_MODF
6211 #endif /* DEBUG_RELOAD */
6213 /* If we're replacing a LABEL_REF with a register, there must
6214 already be an indication (to e.g. flow) which label this
6215 register refers to. */
6216 gcc_assert (GET_CODE (*r->where) != LABEL_REF
6217 || !JUMP_P (insn)
6218 || find_reg_note (insn,
6219 REG_LABEL_OPERAND,
6220 XEXP (*r->where, 0))
6221 || label_is_jump_target_p (XEXP (*r->where, 0), insn));
6223 /* Encapsulate RELOADREG so its machine mode matches what
6224 used to be there. Note that gen_lowpart_common will
6225 do the wrong thing if RELOADREG is multi-word. RELOADREG
6226 will always be a REG here. */
6227 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
6228 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6230 /* If we are putting this into a SUBREG and RELOADREG is a
6231 SUBREG, we would be making nested SUBREGs, so we have to fix
6232 this up. Note that r->where == &SUBREG_REG (*r->subreg_loc). */
6234 if (r->subreg_loc != 0 && GET_CODE (reloadreg) == SUBREG)
6236 if (GET_MODE (*r->subreg_loc)
6237 == GET_MODE (SUBREG_REG (reloadreg)))
6238 *r->subreg_loc = SUBREG_REG (reloadreg);
6239 else
6241 int final_offset =
6242 SUBREG_BYTE (*r->subreg_loc) + SUBREG_BYTE (reloadreg);
6244 /* When working with SUBREGs the rule is that the byte
6245 offset must be a multiple of the SUBREG's mode. */
6246 final_offset = (final_offset /
6247 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6248 final_offset = (final_offset *
6249 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6251 *r->where = SUBREG_REG (reloadreg);
6252 SUBREG_BYTE (*r->subreg_loc) = final_offset;
6255 else
6256 *r->where = reloadreg;
6258 /* If reload got no reg and isn't optional, something's wrong. */
6259 else
6260 gcc_assert (rld[r->what].optional);
6264 /* Make a copy of any replacements being done into X and move those
6265 copies to locations in Y, a copy of X. */
6267 void
6268 copy_replacements (rtx x, rtx y)
6270 /* We can't support X being a SUBREG because we might then need to know its
6271 location if something inside it was replaced. */
6272 gcc_assert (GET_CODE (x) != SUBREG);
6274 copy_replacements_1 (&x, &y, n_replacements);
6277 static void
6278 copy_replacements_1 (rtx *px, rtx *py, int orig_replacements)
6280 int i, j;
6281 rtx x, y;
6282 struct replacement *r;
6283 enum rtx_code code;
6284 const char *fmt;
6286 for (j = 0; j < orig_replacements; j++)
6288 if (replacements[j].subreg_loc == px)
6290 r = &replacements[n_replacements++];
6291 r->where = replacements[j].where;
6292 r->subreg_loc = py;
6293 r->what = replacements[j].what;
6294 r->mode = replacements[j].mode;
6296 else if (replacements[j].where == px)
6298 r = &replacements[n_replacements++];
6299 r->where = py;
6300 r->subreg_loc = 0;
6301 r->what = replacements[j].what;
6302 r->mode = replacements[j].mode;
6306 x = *px;
6307 y = *py;
6308 code = GET_CODE (x);
6309 fmt = GET_RTX_FORMAT (code);
6311 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6313 if (fmt[i] == 'e')
6314 copy_replacements_1 (&XEXP (x, i), &XEXP (y, i), orig_replacements);
6315 else if (fmt[i] == 'E')
6316 for (j = XVECLEN (x, i); --j >= 0; )
6317 copy_replacements_1 (&XVECEXP (x, i, j), &XVECEXP (y, i, j),
6318 orig_replacements);
6322 /* Change any replacements being done to *X to be done to *Y. */
6324 void
6325 move_replacements (rtx *x, rtx *y)
6327 int i;
6329 for (i = 0; i < n_replacements; i++)
6330 if (replacements[i].subreg_loc == x)
6331 replacements[i].subreg_loc = y;
6332 else if (replacements[i].where == x)
6334 replacements[i].where = y;
6335 replacements[i].subreg_loc = 0;
6339 /* If LOC was scheduled to be replaced by something, return the replacement.
6340 Otherwise, return *LOC. */
6343 find_replacement (rtx *loc)
6345 struct replacement *r;
6347 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
6349 rtx reloadreg = rld[r->what].reg_rtx;
6351 if (reloadreg && r->where == loc)
6353 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6354 reloadreg = gen_rtx_REG (r->mode, REGNO (reloadreg));
6356 return reloadreg;
6358 else if (reloadreg && r->subreg_loc == loc)
6360 /* RELOADREG must be either a REG or a SUBREG.
6362 ??? Is it actually still ever a SUBREG? If so, why? */
6364 if (REG_P (reloadreg))
6365 return gen_rtx_REG (GET_MODE (*loc),
6366 (REGNO (reloadreg) +
6367 subreg_regno_offset (REGNO (SUBREG_REG (*loc)),
6368 GET_MODE (SUBREG_REG (*loc)),
6369 SUBREG_BYTE (*loc),
6370 GET_MODE (*loc))));
6371 else if (GET_MODE (reloadreg) == GET_MODE (*loc))
6372 return reloadreg;
6373 else
6375 int final_offset = SUBREG_BYTE (reloadreg) + SUBREG_BYTE (*loc);
6377 /* When working with SUBREGs the rule is that the byte
6378 offset must be a multiple of the SUBREG's mode. */
6379 final_offset = (final_offset / GET_MODE_SIZE (GET_MODE (*loc)));
6380 final_offset = (final_offset * GET_MODE_SIZE (GET_MODE (*loc)));
6381 return gen_rtx_SUBREG (GET_MODE (*loc), SUBREG_REG (reloadreg),
6382 final_offset);
6387 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
6388 what's inside and make a new rtl if so. */
6389 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
6390 || GET_CODE (*loc) == MULT)
6392 rtx x = find_replacement (&XEXP (*loc, 0));
6393 rtx y = find_replacement (&XEXP (*loc, 1));
6395 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
6396 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
6399 return *loc;
6402 /* Return nonzero if register in range [REGNO, ENDREGNO)
6403 appears either explicitly or implicitly in X
6404 other than being stored into (except for earlyclobber operands).
6406 References contained within the substructure at LOC do not count.
6407 LOC may be zero, meaning don't ignore anything.
6409 This is similar to refers_to_regno_p in rtlanal.c except that we
6410 look at equivalences for pseudos that didn't get hard registers. */
6412 static int
6413 refers_to_regno_for_reload_p (unsigned int regno, unsigned int endregno,
6414 rtx x, rtx *loc)
6416 int i;
6417 unsigned int r;
6418 RTX_CODE code;
6419 const char *fmt;
6421 if (x == 0)
6422 return 0;
6424 repeat:
6425 code = GET_CODE (x);
6427 switch (code)
6429 case REG:
6430 r = REGNO (x);
6432 /* If this is a pseudo, a hard register must not have been allocated.
6433 X must therefore either be a constant or be in memory. */
6434 if (r >= FIRST_PSEUDO_REGISTER)
6436 if (reg_equiv_memory_loc[r])
6437 return refers_to_regno_for_reload_p (regno, endregno,
6438 reg_equiv_memory_loc[r],
6439 (rtx*) 0);
6441 gcc_assert (reg_equiv_constant[r] || reg_equiv_invariant[r]);
6442 return 0;
6445 return (endregno > r
6446 && regno < r + (r < FIRST_PSEUDO_REGISTER
6447 ? hard_regno_nregs[r][GET_MODE (x)]
6448 : 1));
6450 case SUBREG:
6451 /* If this is a SUBREG of a hard reg, we can see exactly which
6452 registers are being modified. Otherwise, handle normally. */
6453 if (REG_P (SUBREG_REG (x))
6454 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
6456 unsigned int inner_regno = subreg_regno (x);
6457 unsigned int inner_endregno
6458 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
6459 ? subreg_nregs (x) : 1);
6461 return endregno > inner_regno && regno < inner_endregno;
6463 break;
6465 case CLOBBER:
6466 case SET:
6467 if (&SET_DEST (x) != loc
6468 /* Note setting a SUBREG counts as referring to the REG it is in for
6469 a pseudo but not for hard registers since we can
6470 treat each word individually. */
6471 && ((GET_CODE (SET_DEST (x)) == SUBREG
6472 && loc != &SUBREG_REG (SET_DEST (x))
6473 && REG_P (SUBREG_REG (SET_DEST (x)))
6474 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
6475 && refers_to_regno_for_reload_p (regno, endregno,
6476 SUBREG_REG (SET_DEST (x)),
6477 loc))
6478 /* If the output is an earlyclobber operand, this is
6479 a conflict. */
6480 || ((!REG_P (SET_DEST (x))
6481 || earlyclobber_operand_p (SET_DEST (x)))
6482 && refers_to_regno_for_reload_p (regno, endregno,
6483 SET_DEST (x), loc))))
6484 return 1;
6486 if (code == CLOBBER || loc == &SET_SRC (x))
6487 return 0;
6488 x = SET_SRC (x);
6489 goto repeat;
6491 default:
6492 break;
6495 /* X does not match, so try its subexpressions. */
6497 fmt = GET_RTX_FORMAT (code);
6498 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6500 if (fmt[i] == 'e' && loc != &XEXP (x, i))
6502 if (i == 0)
6504 x = XEXP (x, 0);
6505 goto repeat;
6507 else
6508 if (refers_to_regno_for_reload_p (regno, endregno,
6509 XEXP (x, i), loc))
6510 return 1;
6512 else if (fmt[i] == 'E')
6514 int j;
6515 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6516 if (loc != &XVECEXP (x, i, j)
6517 && refers_to_regno_for_reload_p (regno, endregno,
6518 XVECEXP (x, i, j), loc))
6519 return 1;
6522 return 0;
6525 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
6526 we check if any register number in X conflicts with the relevant register
6527 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
6528 contains a MEM (we don't bother checking for memory addresses that can't
6529 conflict because we expect this to be a rare case.
6531 This function is similar to reg_overlap_mentioned_p in rtlanal.c except
6532 that we look at equivalences for pseudos that didn't get hard registers. */
6535 reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
6537 int regno, endregno;
6539 /* Overly conservative. */
6540 if (GET_CODE (x) == STRICT_LOW_PART
6541 || GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
6542 x = XEXP (x, 0);
6544 /* If either argument is a constant, then modifying X can not affect IN. */
6545 if (CONSTANT_P (x) || CONSTANT_P (in))
6546 return 0;
6547 else if (GET_CODE (x) == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
6548 return refers_to_mem_for_reload_p (in);
6549 else if (GET_CODE (x) == SUBREG)
6551 regno = REGNO (SUBREG_REG (x));
6552 if (regno < FIRST_PSEUDO_REGISTER)
6553 regno += subreg_regno_offset (REGNO (SUBREG_REG (x)),
6554 GET_MODE (SUBREG_REG (x)),
6555 SUBREG_BYTE (x),
6556 GET_MODE (x));
6557 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
6558 ? subreg_nregs (x) : 1);
6560 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6562 else if (REG_P (x))
6564 regno = REGNO (x);
6566 /* If this is a pseudo, it must not have been assigned a hard register.
6567 Therefore, it must either be in memory or be a constant. */
6569 if (regno >= FIRST_PSEUDO_REGISTER)
6571 if (reg_equiv_memory_loc[regno])
6572 return refers_to_mem_for_reload_p (in);
6573 gcc_assert (reg_equiv_constant[regno]);
6574 return 0;
6577 endregno = END_HARD_REGNO (x);
6579 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6581 else if (MEM_P (x))
6582 return refers_to_mem_for_reload_p (in);
6583 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
6584 || GET_CODE (x) == CC0)
6585 return reg_mentioned_p (x, in);
6586 else
6588 gcc_assert (GET_CODE (x) == PLUS);
6590 /* We actually want to know if X is mentioned somewhere inside IN.
6591 We must not say that (plus (sp) (const_int 124)) is in
6592 (plus (sp) (const_int 64)), since that can lead to incorrect reload
6593 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
6594 into a RELOAD_OTHER on behalf of another RELOAD_OTHER. */
6595 while (MEM_P (in))
6596 in = XEXP (in, 0);
6597 if (REG_P (in))
6598 return 0;
6599 else if (GET_CODE (in) == PLUS)
6600 return (rtx_equal_p (x, in)
6601 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
6602 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
6603 else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
6604 || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
6607 gcc_unreachable ();
6610 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
6611 registers. */
6613 static int
6614 refers_to_mem_for_reload_p (rtx x)
6616 const char *fmt;
6617 int i;
6619 if (MEM_P (x))
6620 return 1;
6622 if (REG_P (x))
6623 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
6624 && reg_equiv_memory_loc[REGNO (x)]);
6626 fmt = GET_RTX_FORMAT (GET_CODE (x));
6627 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
6628 if (fmt[i] == 'e'
6629 && (MEM_P (XEXP (x, i))
6630 || refers_to_mem_for_reload_p (XEXP (x, i))))
6631 return 1;
6633 return 0;
6636 /* Check the insns before INSN to see if there is a suitable register
6637 containing the same value as GOAL.
6638 If OTHER is -1, look for a register in class RCLASS.
6639 Otherwise, just see if register number OTHER shares GOAL's value.
6641 Return an rtx for the register found, or zero if none is found.
6643 If RELOAD_REG_P is (short *)1,
6644 we reject any hard reg that appears in reload_reg_rtx
6645 because such a hard reg is also needed coming into this insn.
6647 If RELOAD_REG_P is any other nonzero value,
6648 it is a vector indexed by hard reg number
6649 and we reject any hard reg whose element in the vector is nonnegative
6650 as well as any that appears in reload_reg_rtx.
6652 If GOAL is zero, then GOALREG is a register number; we look
6653 for an equivalent for that register.
6655 MODE is the machine mode of the value we want an equivalence for.
6656 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
6658 This function is used by jump.c as well as in the reload pass.
6660 If GOAL is the sum of the stack pointer and a constant, we treat it
6661 as if it were a constant except that sp is required to be unchanging. */
6664 find_equiv_reg (rtx goal, rtx insn, enum reg_class rclass, int other,
6665 short *reload_reg_p, int goalreg, enum machine_mode mode)
6667 rtx p = insn;
6668 rtx goaltry, valtry, value, where;
6669 rtx pat;
6670 int regno = -1;
6671 int valueno;
6672 int goal_mem = 0;
6673 int goal_const = 0;
6674 int goal_mem_addr_varies = 0;
6675 int need_stable_sp = 0;
6676 int nregs;
6677 int valuenregs;
6678 int num = 0;
6680 if (goal == 0)
6681 regno = goalreg;
6682 else if (REG_P (goal))
6683 regno = REGNO (goal);
6684 else if (MEM_P (goal))
6686 enum rtx_code code = GET_CODE (XEXP (goal, 0));
6687 if (MEM_VOLATILE_P (goal))
6688 return 0;
6689 if (flag_float_store && SCALAR_FLOAT_MODE_P (GET_MODE (goal)))
6690 return 0;
6691 /* An address with side effects must be reexecuted. */
6692 switch (code)
6694 case POST_INC:
6695 case PRE_INC:
6696 case POST_DEC:
6697 case PRE_DEC:
6698 case POST_MODIFY:
6699 case PRE_MODIFY:
6700 return 0;
6701 default:
6702 break;
6704 goal_mem = 1;
6706 else if (CONSTANT_P (goal))
6707 goal_const = 1;
6708 else if (GET_CODE (goal) == PLUS
6709 && XEXP (goal, 0) == stack_pointer_rtx
6710 && CONSTANT_P (XEXP (goal, 1)))
6711 goal_const = need_stable_sp = 1;
6712 else if (GET_CODE (goal) == PLUS
6713 && XEXP (goal, 0) == frame_pointer_rtx
6714 && CONSTANT_P (XEXP (goal, 1)))
6715 goal_const = 1;
6716 else
6717 return 0;
6719 num = 0;
6720 /* Scan insns back from INSN, looking for one that copies
6721 a value into or out of GOAL.
6722 Stop and give up if we reach a label. */
6724 while (1)
6726 p = PREV_INSN (p);
6727 num++;
6728 if (p == 0 || LABEL_P (p)
6729 || num > PARAM_VALUE (PARAM_MAX_RELOAD_SEARCH_INSNS))
6730 return 0;
6732 if (NONJUMP_INSN_P (p)
6733 /* If we don't want spill regs ... */
6734 && (! (reload_reg_p != 0
6735 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6736 /* ... then ignore insns introduced by reload; they aren't
6737 useful and can cause results in reload_as_needed to be
6738 different from what they were when calculating the need for
6739 spills. If we notice an input-reload insn here, we will
6740 reject it below, but it might hide a usable equivalent.
6741 That makes bad code. It may even fail: perhaps no reg was
6742 spilled for this insn because it was assumed we would find
6743 that equivalent. */
6744 || INSN_UID (p) < reload_first_uid))
6746 rtx tem;
6747 pat = single_set (p);
6749 /* First check for something that sets some reg equal to GOAL. */
6750 if (pat != 0
6751 && ((regno >= 0
6752 && true_regnum (SET_SRC (pat)) == regno
6753 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6755 (regno >= 0
6756 && true_regnum (SET_DEST (pat)) == regno
6757 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6759 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6760 /* When looking for stack pointer + const,
6761 make sure we don't use a stack adjust. */
6762 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6763 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6764 || (goal_mem
6765 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6766 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6767 || (goal_mem
6768 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6769 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6770 /* If we are looking for a constant,
6771 and something equivalent to that constant was copied
6772 into a reg, we can use that reg. */
6773 || (goal_const && REG_NOTES (p) != 0
6774 && (tem = find_reg_note (p, REG_EQUIV, NULL_RTX))
6775 && ((rtx_equal_p (XEXP (tem, 0), goal)
6776 && (valueno
6777 = true_regnum (valtry = SET_DEST (pat))) >= 0)
6778 || (REG_P (SET_DEST (pat))
6779 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6780 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6781 && GET_CODE (goal) == CONST_INT
6782 && 0 != (goaltry
6783 = operand_subword (XEXP (tem, 0), 0, 0,
6784 VOIDmode))
6785 && rtx_equal_p (goal, goaltry)
6786 && (valtry
6787 = operand_subword (SET_DEST (pat), 0, 0,
6788 VOIDmode))
6789 && (valueno = true_regnum (valtry)) >= 0)))
6790 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6791 NULL_RTX))
6792 && REG_P (SET_DEST (pat))
6793 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6794 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6795 && GET_CODE (goal) == CONST_INT
6796 && 0 != (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6797 VOIDmode))
6798 && rtx_equal_p (goal, goaltry)
6799 && (valtry
6800 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6801 && (valueno = true_regnum (valtry)) >= 0)))
6803 if (other >= 0)
6805 if (valueno != other)
6806 continue;
6808 else if ((unsigned) valueno >= FIRST_PSEUDO_REGISTER)
6809 continue;
6810 else if (!in_hard_reg_set_p (reg_class_contents[(int) rclass],
6811 mode, valueno))
6812 continue;
6813 value = valtry;
6814 where = p;
6815 break;
6820 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6821 (or copying VALUE into GOAL, if GOAL is also a register).
6822 Now verify that VALUE is really valid. */
6824 /* VALUENO is the register number of VALUE; a hard register. */
6826 /* Don't try to re-use something that is killed in this insn. We want
6827 to be able to trust REG_UNUSED notes. */
6828 if (REG_NOTES (where) != 0 && find_reg_note (where, REG_UNUSED, value))
6829 return 0;
6831 /* If we propose to get the value from the stack pointer or if GOAL is
6832 a MEM based on the stack pointer, we need a stable SP. */
6833 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6834 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6835 goal)))
6836 need_stable_sp = 1;
6838 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6839 if (GET_MODE (value) != mode)
6840 return 0;
6842 /* Reject VALUE if it was loaded from GOAL
6843 and is also a register that appears in the address of GOAL. */
6845 if (goal_mem && value == SET_DEST (single_set (where))
6846 && refers_to_regno_for_reload_p (valueno, end_hard_regno (mode, valueno),
6847 goal, (rtx*) 0))
6848 return 0;
6850 /* Reject registers that overlap GOAL. */
6852 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6853 nregs = hard_regno_nregs[regno][mode];
6854 else
6855 nregs = 1;
6856 valuenregs = hard_regno_nregs[valueno][mode];
6858 if (!goal_mem && !goal_const
6859 && regno + nregs > valueno && regno < valueno + valuenregs)
6860 return 0;
6862 /* Reject VALUE if it is one of the regs reserved for reloads.
6863 Reload1 knows how to reuse them anyway, and it would get
6864 confused if we allocated one without its knowledge.
6865 (Now that insns introduced by reload are ignored above,
6866 this case shouldn't happen, but I'm not positive.) */
6868 if (reload_reg_p != 0 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6870 int i;
6871 for (i = 0; i < valuenregs; ++i)
6872 if (reload_reg_p[valueno + i] >= 0)
6873 return 0;
6876 /* Reject VALUE if it is a register being used for an input reload
6877 even if it is not one of those reserved. */
6879 if (reload_reg_p != 0)
6881 int i;
6882 for (i = 0; i < n_reloads; i++)
6883 if (rld[i].reg_rtx != 0 && rld[i].in)
6885 int regno1 = REGNO (rld[i].reg_rtx);
6886 int nregs1 = hard_regno_nregs[regno1]
6887 [GET_MODE (rld[i].reg_rtx)];
6888 if (regno1 < valueno + valuenregs
6889 && regno1 + nregs1 > valueno)
6890 return 0;
6894 if (goal_mem)
6895 /* We must treat frame pointer as varying here,
6896 since it can vary--in a nonlocal goto as generated by expand_goto. */
6897 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6899 /* Now verify that the values of GOAL and VALUE remain unaltered
6900 until INSN is reached. */
6902 p = insn;
6903 while (1)
6905 p = PREV_INSN (p);
6906 if (p == where)
6907 return value;
6909 /* Don't trust the conversion past a function call
6910 if either of the two is in a call-clobbered register, or memory. */
6911 if (CALL_P (p))
6913 int i;
6915 if (goal_mem || need_stable_sp)
6916 return 0;
6918 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6919 for (i = 0; i < nregs; ++i)
6920 if (call_used_regs[regno + i]
6921 || HARD_REGNO_CALL_PART_CLOBBERED (regno + i, mode))
6922 return 0;
6924 if (valueno >= 0 && valueno < FIRST_PSEUDO_REGISTER)
6925 for (i = 0; i < valuenregs; ++i)
6926 if (call_used_regs[valueno + i]
6927 || HARD_REGNO_CALL_PART_CLOBBERED (valueno + i, mode))
6928 return 0;
6931 if (INSN_P (p))
6933 pat = PATTERN (p);
6935 /* Watch out for unspec_volatile, and volatile asms. */
6936 if (volatile_insn_p (pat))
6937 return 0;
6939 /* If this insn P stores in either GOAL or VALUE, return 0.
6940 If GOAL is a memory ref and this insn writes memory, return 0.
6941 If GOAL is a memory ref and its address is not constant,
6942 and this insn P changes a register used in GOAL, return 0. */
6944 if (GET_CODE (pat) == COND_EXEC)
6945 pat = COND_EXEC_CODE (pat);
6946 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6948 rtx dest = SET_DEST (pat);
6949 while (GET_CODE (dest) == SUBREG
6950 || GET_CODE (dest) == ZERO_EXTRACT
6951 || GET_CODE (dest) == STRICT_LOW_PART)
6952 dest = XEXP (dest, 0);
6953 if (REG_P (dest))
6955 int xregno = REGNO (dest);
6956 int xnregs;
6957 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6958 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
6959 else
6960 xnregs = 1;
6961 if (xregno < regno + nregs && xregno + xnregs > regno)
6962 return 0;
6963 if (xregno < valueno + valuenregs
6964 && xregno + xnregs > valueno)
6965 return 0;
6966 if (goal_mem_addr_varies
6967 && reg_overlap_mentioned_for_reload_p (dest, goal))
6968 return 0;
6969 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6970 return 0;
6972 else if (goal_mem && MEM_P (dest)
6973 && ! push_operand (dest, GET_MODE (dest)))
6974 return 0;
6975 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6976 && reg_equiv_memory_loc[regno] != 0)
6977 return 0;
6978 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6979 return 0;
6981 else if (GET_CODE (pat) == PARALLEL)
6983 int i;
6984 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6986 rtx v1 = XVECEXP (pat, 0, i);
6987 if (GET_CODE (v1) == COND_EXEC)
6988 v1 = COND_EXEC_CODE (v1);
6989 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6991 rtx dest = SET_DEST (v1);
6992 while (GET_CODE (dest) == SUBREG
6993 || GET_CODE (dest) == ZERO_EXTRACT
6994 || GET_CODE (dest) == STRICT_LOW_PART)
6995 dest = XEXP (dest, 0);
6996 if (REG_P (dest))
6998 int xregno = REGNO (dest);
6999 int xnregs;
7000 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
7001 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
7002 else
7003 xnregs = 1;
7004 if (xregno < regno + nregs
7005 && xregno + xnregs > regno)
7006 return 0;
7007 if (xregno < valueno + valuenregs
7008 && xregno + xnregs > valueno)
7009 return 0;
7010 if (goal_mem_addr_varies
7011 && reg_overlap_mentioned_for_reload_p (dest,
7012 goal))
7013 return 0;
7014 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
7015 return 0;
7017 else if (goal_mem && MEM_P (dest)
7018 && ! push_operand (dest, GET_MODE (dest)))
7019 return 0;
7020 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
7021 && reg_equiv_memory_loc[regno] != 0)
7022 return 0;
7023 else if (need_stable_sp
7024 && push_operand (dest, GET_MODE (dest)))
7025 return 0;
7030 if (CALL_P (p) && CALL_INSN_FUNCTION_USAGE (p))
7032 rtx link;
7034 for (link = CALL_INSN_FUNCTION_USAGE (p); XEXP (link, 1) != 0;
7035 link = XEXP (link, 1))
7037 pat = XEXP (link, 0);
7038 if (GET_CODE (pat) == CLOBBER)
7040 rtx dest = SET_DEST (pat);
7042 if (REG_P (dest))
7044 int xregno = REGNO (dest);
7045 int xnregs
7046 = hard_regno_nregs[xregno][GET_MODE (dest)];
7048 if (xregno < regno + nregs
7049 && xregno + xnregs > regno)
7050 return 0;
7051 else if (xregno < valueno + valuenregs
7052 && xregno + xnregs > valueno)
7053 return 0;
7054 else if (goal_mem_addr_varies
7055 && reg_overlap_mentioned_for_reload_p (dest,
7056 goal))
7057 return 0;
7060 else if (goal_mem && MEM_P (dest)
7061 && ! push_operand (dest, GET_MODE (dest)))
7062 return 0;
7063 else if (need_stable_sp
7064 && push_operand (dest, GET_MODE (dest)))
7065 return 0;
7070 #ifdef AUTO_INC_DEC
7071 /* If this insn auto-increments or auto-decrements
7072 either regno or valueno, return 0 now.
7073 If GOAL is a memory ref and its address is not constant,
7074 and this insn P increments a register used in GOAL, return 0. */
7076 rtx link;
7078 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
7079 if (REG_NOTE_KIND (link) == REG_INC
7080 && REG_P (XEXP (link, 0)))
7082 int incno = REGNO (XEXP (link, 0));
7083 if (incno < regno + nregs && incno >= regno)
7084 return 0;
7085 if (incno < valueno + valuenregs && incno >= valueno)
7086 return 0;
7087 if (goal_mem_addr_varies
7088 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
7089 goal))
7090 return 0;
7093 #endif
7098 /* Find a place where INCED appears in an increment or decrement operator
7099 within X, and return the amount INCED is incremented or decremented by.
7100 The value is always positive. */
7102 static int
7103 find_inc_amount (rtx x, rtx inced)
7105 enum rtx_code code = GET_CODE (x);
7106 const char *fmt;
7107 int i;
7109 if (code == MEM)
7111 rtx addr = XEXP (x, 0);
7112 if ((GET_CODE (addr) == PRE_DEC
7113 || GET_CODE (addr) == POST_DEC
7114 || GET_CODE (addr) == PRE_INC
7115 || GET_CODE (addr) == POST_INC)
7116 && XEXP (addr, 0) == inced)
7117 return GET_MODE_SIZE (GET_MODE (x));
7118 else if ((GET_CODE (addr) == PRE_MODIFY
7119 || GET_CODE (addr) == POST_MODIFY)
7120 && GET_CODE (XEXP (addr, 1)) == PLUS
7121 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
7122 && XEXP (addr, 0) == inced
7123 && GET_CODE (XEXP (XEXP (addr, 1), 1)) == CONST_INT)
7125 i = INTVAL (XEXP (XEXP (addr, 1), 1));
7126 return i < 0 ? -i : i;
7130 fmt = GET_RTX_FORMAT (code);
7131 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7133 if (fmt[i] == 'e')
7135 int tem = find_inc_amount (XEXP (x, i), inced);
7136 if (tem != 0)
7137 return tem;
7139 if (fmt[i] == 'E')
7141 int j;
7142 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7144 int tem = find_inc_amount (XVECEXP (x, i, j), inced);
7145 if (tem != 0)
7146 return tem;
7151 return 0;
7154 /* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
7155 REG_INC note in insn INSN. REGNO must refer to a hard register. */
7157 #ifdef AUTO_INC_DEC
7158 static int
7159 reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
7160 rtx insn)
7162 rtx link;
7164 gcc_assert (insn);
7166 if (! INSN_P (insn))
7167 return 0;
7169 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
7170 if (REG_NOTE_KIND (link) == REG_INC)
7172 unsigned int test = (int) REGNO (XEXP (link, 0));
7173 if (test >= regno && test < endregno)
7174 return 1;
7176 return 0;
7178 #else
7180 #define reg_inc_found_and_valid_p(regno,endregno,insn) 0
7182 #endif
7184 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
7185 If SETS is 1, also consider SETs. If SETS is 2, enable checking
7186 REG_INC. REGNO must refer to a hard register. */
7189 regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
7190 int sets)
7192 unsigned int nregs, endregno;
7194 /* regno must be a hard register. */
7195 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
7197 nregs = hard_regno_nregs[regno][mode];
7198 endregno = regno + nregs;
7200 if ((GET_CODE (PATTERN (insn)) == CLOBBER
7201 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7202 && REG_P (XEXP (PATTERN (insn), 0)))
7204 unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
7206 return test >= regno && test < endregno;
7209 if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
7210 return 1;
7212 if (GET_CODE (PATTERN (insn)) == PARALLEL)
7214 int i = XVECLEN (PATTERN (insn), 0) - 1;
7216 for (; i >= 0; i--)
7218 rtx elt = XVECEXP (PATTERN (insn), 0, i);
7219 if ((GET_CODE (elt) == CLOBBER
7220 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7221 && REG_P (XEXP (elt, 0)))
7223 unsigned int test = REGNO (XEXP (elt, 0));
7225 if (test >= regno && test < endregno)
7226 return 1;
7228 if (sets == 2
7229 && reg_inc_found_and_valid_p (regno, endregno, elt))
7230 return 1;
7234 return 0;
7237 /* Find the low part, with mode MODE, of a hard regno RELOADREG. */
7239 reload_adjust_reg_for_mode (rtx reloadreg, enum machine_mode mode)
7241 int regno;
7243 if (GET_MODE (reloadreg) == mode)
7244 return reloadreg;
7246 regno = REGNO (reloadreg);
7248 if (WORDS_BIG_ENDIAN)
7249 regno += (int) hard_regno_nregs[regno][GET_MODE (reloadreg)]
7250 - (int) hard_regno_nregs[regno][mode];
7252 return gen_rtx_REG (mode, regno);
7255 static const char *const reload_when_needed_name[] =
7257 "RELOAD_FOR_INPUT",
7258 "RELOAD_FOR_OUTPUT",
7259 "RELOAD_FOR_INSN",
7260 "RELOAD_FOR_INPUT_ADDRESS",
7261 "RELOAD_FOR_INPADDR_ADDRESS",
7262 "RELOAD_FOR_OUTPUT_ADDRESS",
7263 "RELOAD_FOR_OUTADDR_ADDRESS",
7264 "RELOAD_FOR_OPERAND_ADDRESS",
7265 "RELOAD_FOR_OPADDR_ADDR",
7266 "RELOAD_OTHER",
7267 "RELOAD_FOR_OTHER_ADDRESS"
7270 /* These functions are used to print the variables set by 'find_reloads' */
7272 void
7273 debug_reload_to_stream (FILE *f)
7275 int r;
7276 const char *prefix;
7278 if (! f)
7279 f = stderr;
7280 for (r = 0; r < n_reloads; r++)
7282 fprintf (f, "Reload %d: ", r);
7284 if (rld[r].in != 0)
7286 fprintf (f, "reload_in (%s) = ",
7287 GET_MODE_NAME (rld[r].inmode));
7288 print_inline_rtx (f, rld[r].in, 24);
7289 fprintf (f, "\n\t");
7292 if (rld[r].out != 0)
7294 fprintf (f, "reload_out (%s) = ",
7295 GET_MODE_NAME (rld[r].outmode));
7296 print_inline_rtx (f, rld[r].out, 24);
7297 fprintf (f, "\n\t");
7300 fprintf (f, "%s, ", reg_class_names[(int) rld[r].rclass]);
7302 fprintf (f, "%s (opnum = %d)",
7303 reload_when_needed_name[(int) rld[r].when_needed],
7304 rld[r].opnum);
7306 if (rld[r].optional)
7307 fprintf (f, ", optional");
7309 if (rld[r].nongroup)
7310 fprintf (f, ", nongroup");
7312 if (rld[r].inc != 0)
7313 fprintf (f, ", inc by %d", rld[r].inc);
7315 if (rld[r].nocombine)
7316 fprintf (f, ", can't combine");
7318 if (rld[r].secondary_p)
7319 fprintf (f, ", secondary_reload_p");
7321 if (rld[r].in_reg != 0)
7323 fprintf (f, "\n\treload_in_reg: ");
7324 print_inline_rtx (f, rld[r].in_reg, 24);
7327 if (rld[r].out_reg != 0)
7329 fprintf (f, "\n\treload_out_reg: ");
7330 print_inline_rtx (f, rld[r].out_reg, 24);
7333 if (rld[r].reg_rtx != 0)
7335 fprintf (f, "\n\treload_reg_rtx: ");
7336 print_inline_rtx (f, rld[r].reg_rtx, 24);
7339 prefix = "\n\t";
7340 if (rld[r].secondary_in_reload != -1)
7342 fprintf (f, "%ssecondary_in_reload = %d",
7343 prefix, rld[r].secondary_in_reload);
7344 prefix = ", ";
7347 if (rld[r].secondary_out_reload != -1)
7348 fprintf (f, "%ssecondary_out_reload = %d\n",
7349 prefix, rld[r].secondary_out_reload);
7351 prefix = "\n\t";
7352 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
7354 fprintf (f, "%ssecondary_in_icode = %s", prefix,
7355 insn_data[rld[r].secondary_in_icode].name);
7356 prefix = ", ";
7359 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
7360 fprintf (f, "%ssecondary_out_icode = %s", prefix,
7361 insn_data[rld[r].secondary_out_icode].name);
7363 fprintf (f, "\n");
7367 void
7368 debug_reload (void)
7370 debug_reload_to_stream (stderr);