configure: Regenerate for new libtool.
[official-gcc.git] / gcc / reload.c
blobe353c50acdb19f7473c59c64e690c65eb56007c3
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 (flag_ira
1553 ? DF_LR_OUT (ENTRY_BLOCK_PTR)
1554 : DF_LIVE_OUT (ENTRY_BLOCK_PTR),
1555 ORIGINAL_REGNO (XEXP (note, 0)))
1556 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1))
1557 && ! refers_to_regno_for_reload_p (regno,
1558 end_hard_regno (rel_mode,
1559 regno),
1560 PATTERN (this_insn), inloc)
1561 /* If this is also an output reload, IN cannot be used as
1562 the reload register if it is set in this insn unless IN
1563 is also OUT. */
1564 && (out == 0 || in == out
1565 || ! hard_reg_set_here_p (regno,
1566 end_hard_regno (rel_mode, regno),
1567 PATTERN (this_insn)))
1568 /* ??? Why is this code so different from the previous?
1569 Is there any simple coherent way to describe the two together?
1570 What's going on here. */
1571 && (in != out
1572 || (GET_CODE (in) == SUBREG
1573 && (((GET_MODE_SIZE (GET_MODE (in)) + (UNITS_PER_WORD - 1))
1574 / UNITS_PER_WORD)
1575 == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1576 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
1577 /* Make sure the operand fits in the reg that dies. */
1578 && (GET_MODE_SIZE (rel_mode)
1579 <= GET_MODE_SIZE (GET_MODE (XEXP (note, 0))))
1580 && HARD_REGNO_MODE_OK (regno, inmode)
1581 && HARD_REGNO_MODE_OK (regno, outmode))
1583 unsigned int offs;
1584 unsigned int nregs = MAX (hard_regno_nregs[regno][inmode],
1585 hard_regno_nregs[regno][outmode]);
1587 for (offs = 0; offs < nregs; offs++)
1588 if (fixed_regs[regno + offs]
1589 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1590 regno + offs))
1591 break;
1593 if (offs == nregs
1594 && (! (refers_to_regno_for_reload_p
1595 (regno, end_hard_regno (inmode, regno), in, (rtx *) 0))
1596 || can_reload_into (in, regno, inmode)))
1598 rld[i].reg_rtx = gen_rtx_REG (rel_mode, regno);
1599 break;
1604 if (out)
1605 output_reloadnum = i;
1607 return i;
1610 /* Record an additional place we must replace a value
1611 for which we have already recorded a reload.
1612 RELOADNUM is the value returned by push_reload
1613 when the reload was recorded.
1614 This is used in insn patterns that use match_dup. */
1616 static void
1617 push_replacement (rtx *loc, int reloadnum, enum machine_mode mode)
1619 if (replace_reloads)
1621 struct replacement *r = &replacements[n_replacements++];
1622 r->what = reloadnum;
1623 r->where = loc;
1624 r->subreg_loc = 0;
1625 r->mode = mode;
1629 /* Duplicate any replacement we have recorded to apply at
1630 location ORIG_LOC to also be performed at DUP_LOC.
1631 This is used in insn patterns that use match_dup. */
1633 static void
1634 dup_replacements (rtx *dup_loc, rtx *orig_loc)
1636 int i, n = n_replacements;
1638 for (i = 0; i < n; i++)
1640 struct replacement *r = &replacements[i];
1641 if (r->where == orig_loc)
1642 push_replacement (dup_loc, r->what, r->mode);
1646 /* Transfer all replacements that used to be in reload FROM to be in
1647 reload TO. */
1649 void
1650 transfer_replacements (int to, int from)
1652 int i;
1654 for (i = 0; i < n_replacements; i++)
1655 if (replacements[i].what == from)
1656 replacements[i].what = to;
1659 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1660 or a subpart of it. If we have any replacements registered for IN_RTX,
1661 cancel the reloads that were supposed to load them.
1662 Return nonzero if we canceled any reloads. */
1664 remove_address_replacements (rtx in_rtx)
1666 int i, j;
1667 char reload_flags[MAX_RELOADS];
1668 int something_changed = 0;
1670 memset (reload_flags, 0, sizeof reload_flags);
1671 for (i = 0, j = 0; i < n_replacements; i++)
1673 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1674 reload_flags[replacements[i].what] |= 1;
1675 else
1677 replacements[j++] = replacements[i];
1678 reload_flags[replacements[i].what] |= 2;
1681 /* Note that the following store must be done before the recursive calls. */
1682 n_replacements = j;
1684 for (i = n_reloads - 1; i >= 0; i--)
1686 if (reload_flags[i] == 1)
1688 deallocate_reload_reg (i);
1689 remove_address_replacements (rld[i].in);
1690 rld[i].in = 0;
1691 something_changed = 1;
1694 return something_changed;
1697 /* If there is only one output reload, and it is not for an earlyclobber
1698 operand, try to combine it with a (logically unrelated) input reload
1699 to reduce the number of reload registers needed.
1701 This is safe if the input reload does not appear in
1702 the value being output-reloaded, because this implies
1703 it is not needed any more once the original insn completes.
1705 If that doesn't work, see we can use any of the registers that
1706 die in this insn as a reload register. We can if it is of the right
1707 class and does not appear in the value being output-reloaded. */
1709 static void
1710 combine_reloads (void)
1712 int i, regno;
1713 int output_reload = -1;
1714 int secondary_out = -1;
1715 rtx note;
1717 /* Find the output reload; return unless there is exactly one
1718 and that one is mandatory. */
1720 for (i = 0; i < n_reloads; i++)
1721 if (rld[i].out != 0)
1723 if (output_reload >= 0)
1724 return;
1725 output_reload = i;
1728 if (output_reload < 0 || rld[output_reload].optional)
1729 return;
1731 /* An input-output reload isn't combinable. */
1733 if (rld[output_reload].in != 0)
1734 return;
1736 /* If this reload is for an earlyclobber operand, we can't do anything. */
1737 if (earlyclobber_operand_p (rld[output_reload].out))
1738 return;
1740 /* If there is a reload for part of the address of this operand, we would
1741 need to change it to RELOAD_FOR_OTHER_ADDRESS. But that would extend
1742 its life to the point where doing this combine would not lower the
1743 number of spill registers needed. */
1744 for (i = 0; i < n_reloads; i++)
1745 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
1746 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
1747 && rld[i].opnum == rld[output_reload].opnum)
1748 return;
1750 /* Check each input reload; can we combine it? */
1752 for (i = 0; i < n_reloads; i++)
1753 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1754 /* Life span of this reload must not extend past main insn. */
1755 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1756 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1757 && rld[i].when_needed != RELOAD_OTHER
1758 && (CLASS_MAX_NREGS (rld[i].rclass, rld[i].inmode)
1759 == CLASS_MAX_NREGS (rld[output_reload].rclass,
1760 rld[output_reload].outmode))
1761 && rld[i].inc == 0
1762 && rld[i].reg_rtx == 0
1763 #ifdef SECONDARY_MEMORY_NEEDED
1764 /* Don't combine two reloads with different secondary
1765 memory locations. */
1766 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1767 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1768 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1769 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1770 #endif
1771 && (SMALL_REGISTER_CLASSES
1772 ? (rld[i].rclass == rld[output_reload].rclass)
1773 : (reg_class_subset_p (rld[i].rclass,
1774 rld[output_reload].rclass)
1775 || reg_class_subset_p (rld[output_reload].rclass,
1776 rld[i].rclass)))
1777 && (MATCHES (rld[i].in, rld[output_reload].out)
1778 /* Args reversed because the first arg seems to be
1779 the one that we imagine being modified
1780 while the second is the one that might be affected. */
1781 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1782 rld[i].in)
1783 /* However, if the input is a register that appears inside
1784 the output, then we also can't share.
1785 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1786 If the same reload reg is used for both reg 69 and the
1787 result to be stored in memory, then that result
1788 will clobber the address of the memory ref. */
1789 && ! (REG_P (rld[i].in)
1790 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1791 rld[output_reload].out))))
1792 && ! reload_inner_reg_of_subreg (rld[i].in, rld[i].inmode,
1793 rld[i].when_needed != RELOAD_FOR_INPUT)
1794 && (reg_class_size[(int) rld[i].rclass]
1795 || SMALL_REGISTER_CLASSES)
1796 /* We will allow making things slightly worse by combining an
1797 input and an output, but no worse than that. */
1798 && (rld[i].when_needed == RELOAD_FOR_INPUT
1799 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1801 int j;
1803 /* We have found a reload to combine with! */
1804 rld[i].out = rld[output_reload].out;
1805 rld[i].out_reg = rld[output_reload].out_reg;
1806 rld[i].outmode = rld[output_reload].outmode;
1807 /* Mark the old output reload as inoperative. */
1808 rld[output_reload].out = 0;
1809 /* The combined reload is needed for the entire insn. */
1810 rld[i].when_needed = RELOAD_OTHER;
1811 /* If the output reload had a secondary reload, copy it. */
1812 if (rld[output_reload].secondary_out_reload != -1)
1814 rld[i].secondary_out_reload
1815 = rld[output_reload].secondary_out_reload;
1816 rld[i].secondary_out_icode
1817 = rld[output_reload].secondary_out_icode;
1820 #ifdef SECONDARY_MEMORY_NEEDED
1821 /* Copy any secondary MEM. */
1822 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1823 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1824 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1825 #endif
1826 /* If required, minimize the register class. */
1827 if (reg_class_subset_p (rld[output_reload].rclass,
1828 rld[i].rclass))
1829 rld[i].rclass = rld[output_reload].rclass;
1831 /* Transfer all replacements from the old reload to the combined. */
1832 for (j = 0; j < n_replacements; j++)
1833 if (replacements[j].what == output_reload)
1834 replacements[j].what = i;
1836 return;
1839 /* If this insn has only one operand that is modified or written (assumed
1840 to be the first), it must be the one corresponding to this reload. It
1841 is safe to use anything that dies in this insn for that output provided
1842 that it does not occur in the output (we already know it isn't an
1843 earlyclobber. If this is an asm insn, give up. */
1845 if (INSN_CODE (this_insn) == -1)
1846 return;
1848 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1849 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1850 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1851 return;
1853 /* See if some hard register that dies in this insn and is not used in
1854 the output is the right class. Only works if the register we pick
1855 up can fully hold our output reload. */
1856 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1857 if (REG_NOTE_KIND (note) == REG_DEAD
1858 && REG_P (XEXP (note, 0))
1859 && !reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1860 rld[output_reload].out)
1861 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1862 && HARD_REGNO_MODE_OK (regno, rld[output_reload].outmode)
1863 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].rclass],
1864 regno)
1865 && (hard_regno_nregs[regno][rld[output_reload].outmode]
1866 <= hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))])
1867 /* Ensure that a secondary or tertiary reload for this output
1868 won't want this register. */
1869 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1870 || (!(TEST_HARD_REG_BIT
1871 (reg_class_contents[(int) rld[secondary_out].rclass], regno))
1872 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1873 || !(TEST_HARD_REG_BIT
1874 (reg_class_contents[(int) rld[secondary_out].rclass],
1875 regno)))))
1876 && !fixed_regs[regno]
1877 /* Check that a former pseudo is valid; see find_dummy_reload. */
1878 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1879 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR),
1880 ORIGINAL_REGNO (XEXP (note, 0)))
1881 && hard_regno_nregs[regno][GET_MODE (XEXP (note, 0))] == 1)))
1883 rld[output_reload].reg_rtx
1884 = gen_rtx_REG (rld[output_reload].outmode, regno);
1885 return;
1889 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1890 See if one of IN and OUT is a register that may be used;
1891 this is desirable since a spill-register won't be needed.
1892 If so, return the register rtx that proves acceptable.
1894 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1895 RCLASS is the register class required for the reload.
1897 If FOR_REAL is >= 0, it is the number of the reload,
1898 and in some cases when it can be discovered that OUT doesn't need
1899 to be computed, clear out rld[FOR_REAL].out.
1901 If FOR_REAL is -1, this should not be done, because this call
1902 is just to see if a register can be found, not to find and install it.
1904 EARLYCLOBBER is nonzero if OUT is an earlyclobber operand. This
1905 puts an additional constraint on being able to use IN for OUT since
1906 IN must not appear elsewhere in the insn (it is assumed that IN itself
1907 is safe from the earlyclobber). */
1909 static rtx
1910 find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc,
1911 enum machine_mode inmode, enum machine_mode outmode,
1912 enum reg_class rclass, int for_real, int earlyclobber)
1914 rtx in = real_in;
1915 rtx out = real_out;
1916 int in_offset = 0;
1917 int out_offset = 0;
1918 rtx value = 0;
1920 /* If operands exceed a word, we can't use either of them
1921 unless they have the same size. */
1922 if (GET_MODE_SIZE (outmode) != GET_MODE_SIZE (inmode)
1923 && (GET_MODE_SIZE (outmode) > UNITS_PER_WORD
1924 || GET_MODE_SIZE (inmode) > UNITS_PER_WORD))
1925 return 0;
1927 /* Note that {in,out}_offset are needed only when 'in' or 'out'
1928 respectively refers to a hard register. */
1930 /* Find the inside of any subregs. */
1931 while (GET_CODE (out) == SUBREG)
1933 if (REG_P (SUBREG_REG (out))
1934 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER)
1935 out_offset += subreg_regno_offset (REGNO (SUBREG_REG (out)),
1936 GET_MODE (SUBREG_REG (out)),
1937 SUBREG_BYTE (out),
1938 GET_MODE (out));
1939 out = SUBREG_REG (out);
1941 while (GET_CODE (in) == SUBREG)
1943 if (REG_P (SUBREG_REG (in))
1944 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER)
1945 in_offset += subreg_regno_offset (REGNO (SUBREG_REG (in)),
1946 GET_MODE (SUBREG_REG (in)),
1947 SUBREG_BYTE (in),
1948 GET_MODE (in));
1949 in = SUBREG_REG (in);
1952 /* Narrow down the reg class, the same way push_reload will;
1953 otherwise we might find a dummy now, but push_reload won't. */
1955 enum reg_class preferred_class = PREFERRED_RELOAD_CLASS (in, rclass);
1956 if (preferred_class != NO_REGS)
1957 rclass = preferred_class;
1960 /* See if OUT will do. */
1961 if (REG_P (out)
1962 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1964 unsigned int regno = REGNO (out) + out_offset;
1965 unsigned int nwords = hard_regno_nregs[regno][outmode];
1966 rtx saved_rtx;
1968 /* When we consider whether the insn uses OUT,
1969 ignore references within IN. They don't prevent us
1970 from copying IN into OUT, because those refs would
1971 move into the insn that reloads IN.
1973 However, we only ignore IN in its role as this reload.
1974 If the insn uses IN elsewhere and it contains OUT,
1975 that counts. We can't be sure it's the "same" operand
1976 so it might not go through this reload. */
1977 saved_rtx = *inloc;
1978 *inloc = const0_rtx;
1980 if (regno < FIRST_PSEUDO_REGISTER
1981 && HARD_REGNO_MODE_OK (regno, outmode)
1982 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
1983 PATTERN (this_insn), outloc))
1985 unsigned int i;
1987 for (i = 0; i < nwords; i++)
1988 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1989 regno + i))
1990 break;
1992 if (i == nwords)
1994 if (REG_P (real_out))
1995 value = real_out;
1996 else
1997 value = gen_rtx_REG (outmode, regno);
2001 *inloc = saved_rtx;
2004 /* Consider using IN if OUT was not acceptable
2005 or if OUT dies in this insn (like the quotient in a divmod insn).
2006 We can't use IN unless it is dies in this insn,
2007 which means we must know accurately which hard regs are live.
2008 Also, the result can't go in IN if IN is used within OUT,
2009 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
2010 if (hard_regs_live_known
2011 && REG_P (in)
2012 && REGNO (in) < FIRST_PSEUDO_REGISTER
2013 && (value == 0
2014 || find_reg_note (this_insn, REG_UNUSED, real_out))
2015 && find_reg_note (this_insn, REG_DEAD, real_in)
2016 && !fixed_regs[REGNO (in)]
2017 && HARD_REGNO_MODE_OK (REGNO (in),
2018 /* The only case where out and real_out might
2019 have different modes is where real_out
2020 is a subreg, and in that case, out
2021 has a real mode. */
2022 (GET_MODE (out) != VOIDmode
2023 ? GET_MODE (out) : outmode))
2024 && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER
2025 /* However only do this if we can be sure that this input
2026 operand doesn't correspond with an uninitialized pseudo.
2027 global can assign some hardreg to it that is the same as
2028 the one assigned to a different, also live pseudo (as it
2029 can ignore the conflict). We must never introduce writes
2030 to such hardregs, as they would clobber the other live
2031 pseudo. See PR 20973. */
2032 || (!bitmap_bit_p (flag_ira
2033 ? DF_LR_OUT (ENTRY_BLOCK_PTR)
2034 : DF_LIVE_OUT (ENTRY_BLOCK_PTR),
2035 ORIGINAL_REGNO (in))
2036 /* Similarly, only do this if we can be sure that the death
2037 note is still valid. global can assign some hardreg to
2038 the pseudo referenced in the note and simultaneously a
2039 subword of this hardreg to a different, also live pseudo,
2040 because only another subword of the hardreg is actually
2041 used in the insn. This cannot happen if the pseudo has
2042 been assigned exactly one hardreg. See PR 33732. */
2043 && hard_regno_nregs[REGNO (in)][GET_MODE (in)] == 1)))
2045 unsigned int regno = REGNO (in) + in_offset;
2046 unsigned int nwords = hard_regno_nregs[regno][inmode];
2048 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, (rtx*) 0)
2049 && ! hard_reg_set_here_p (regno, regno + nwords,
2050 PATTERN (this_insn))
2051 && (! earlyclobber
2052 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
2053 PATTERN (this_insn), inloc)))
2055 unsigned int i;
2057 for (i = 0; i < nwords; i++)
2058 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2059 regno + i))
2060 break;
2062 if (i == nwords)
2064 /* If we were going to use OUT as the reload reg
2065 and changed our mind, it means OUT is a dummy that
2066 dies here. So don't bother copying value to it. */
2067 if (for_real >= 0 && value == real_out)
2068 rld[for_real].out = 0;
2069 if (REG_P (real_in))
2070 value = real_in;
2071 else
2072 value = gen_rtx_REG (inmode, regno);
2077 return value;
2080 /* This page contains subroutines used mainly for determining
2081 whether the IN or an OUT of a reload can serve as the
2082 reload register. */
2084 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
2087 earlyclobber_operand_p (rtx x)
2089 int i;
2091 for (i = 0; i < n_earlyclobbers; i++)
2092 if (reload_earlyclobbers[i] == x)
2093 return 1;
2095 return 0;
2098 /* Return 1 if expression X alters a hard reg in the range
2099 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
2100 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
2101 X should be the body of an instruction. */
2103 static int
2104 hard_reg_set_here_p (unsigned int beg_regno, unsigned int end_regno, rtx x)
2106 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
2108 rtx op0 = SET_DEST (x);
2110 while (GET_CODE (op0) == SUBREG)
2111 op0 = SUBREG_REG (op0);
2112 if (REG_P (op0))
2114 unsigned int r = REGNO (op0);
2116 /* See if this reg overlaps range under consideration. */
2117 if (r < end_regno
2118 && end_hard_regno (GET_MODE (op0), r) > beg_regno)
2119 return 1;
2122 else if (GET_CODE (x) == PARALLEL)
2124 int i = XVECLEN (x, 0) - 1;
2126 for (; i >= 0; i--)
2127 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
2128 return 1;
2131 return 0;
2134 /* Return 1 if ADDR is a valid memory address for mode MODE,
2135 and check that each pseudo reg has the proper kind of
2136 hard reg. */
2139 strict_memory_address_p (enum machine_mode mode ATTRIBUTE_UNUSED, rtx addr)
2141 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
2142 return 0;
2144 win:
2145 return 1;
2148 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
2149 if they are the same hard reg, and has special hacks for
2150 autoincrement and autodecrement.
2151 This is specifically intended for find_reloads to use
2152 in determining whether two operands match.
2153 X is the operand whose number is the lower of the two.
2155 The value is 2 if Y contains a pre-increment that matches
2156 a non-incrementing address in X. */
2158 /* ??? To be completely correct, we should arrange to pass
2159 for X the output operand and for Y the input operand.
2160 For now, we assume that the output operand has the lower number
2161 because that is natural in (SET output (... input ...)). */
2164 operands_match_p (rtx x, rtx y)
2166 int i;
2167 RTX_CODE code = GET_CODE (x);
2168 const char *fmt;
2169 int success_2;
2171 if (x == y)
2172 return 1;
2173 if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
2174 && (REG_P (y) || (GET_CODE (y) == SUBREG
2175 && REG_P (SUBREG_REG (y)))))
2177 int j;
2179 if (code == SUBREG)
2181 i = REGNO (SUBREG_REG (x));
2182 if (i >= FIRST_PSEUDO_REGISTER)
2183 goto slow;
2184 i += subreg_regno_offset (REGNO (SUBREG_REG (x)),
2185 GET_MODE (SUBREG_REG (x)),
2186 SUBREG_BYTE (x),
2187 GET_MODE (x));
2189 else
2190 i = REGNO (x);
2192 if (GET_CODE (y) == SUBREG)
2194 j = REGNO (SUBREG_REG (y));
2195 if (j >= FIRST_PSEUDO_REGISTER)
2196 goto slow;
2197 j += subreg_regno_offset (REGNO (SUBREG_REG (y)),
2198 GET_MODE (SUBREG_REG (y)),
2199 SUBREG_BYTE (y),
2200 GET_MODE (y));
2202 else
2203 j = REGNO (y);
2205 /* On a WORDS_BIG_ENDIAN machine, point to the last register of a
2206 multiple hard register group of scalar integer registers, so that
2207 for example (reg:DI 0) and (reg:SI 1) will be considered the same
2208 register. */
2209 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
2210 && SCALAR_INT_MODE_P (GET_MODE (x))
2211 && i < FIRST_PSEUDO_REGISTER)
2212 i += hard_regno_nregs[i][GET_MODE (x)] - 1;
2213 if (WORDS_BIG_ENDIAN && GET_MODE_SIZE (GET_MODE (y)) > UNITS_PER_WORD
2214 && SCALAR_INT_MODE_P (GET_MODE (y))
2215 && j < FIRST_PSEUDO_REGISTER)
2216 j += hard_regno_nregs[j][GET_MODE (y)] - 1;
2218 return i == j;
2220 /* If two operands must match, because they are really a single
2221 operand of an assembler insn, then two postincrements are invalid
2222 because the assembler insn would increment only once.
2223 On the other hand, a postincrement matches ordinary indexing
2224 if the postincrement is the output operand. */
2225 if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
2226 return operands_match_p (XEXP (x, 0), y);
2227 /* Two preincrements are invalid
2228 because the assembler insn would increment only once.
2229 On the other hand, a preincrement matches ordinary indexing
2230 if the preincrement is the input operand.
2231 In this case, return 2, since some callers need to do special
2232 things when this happens. */
2233 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
2234 || GET_CODE (y) == PRE_MODIFY)
2235 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2237 slow:
2239 /* Now we have disposed of all the cases in which different rtx codes
2240 can match. */
2241 if (code != GET_CODE (y))
2242 return 0;
2244 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2245 if (GET_MODE (x) != GET_MODE (y))
2246 return 0;
2248 switch (code)
2250 case CONST_INT:
2251 case CONST_DOUBLE:
2252 case CONST_FIXED:
2253 return 0;
2255 case LABEL_REF:
2256 return XEXP (x, 0) == XEXP (y, 0);
2257 case SYMBOL_REF:
2258 return XSTR (x, 0) == XSTR (y, 0);
2260 default:
2261 break;
2264 /* Compare the elements. If any pair of corresponding elements
2265 fail to match, return 0 for the whole things. */
2267 success_2 = 0;
2268 fmt = GET_RTX_FORMAT (code);
2269 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2271 int val, j;
2272 switch (fmt[i])
2274 case 'w':
2275 if (XWINT (x, i) != XWINT (y, i))
2276 return 0;
2277 break;
2279 case 'i':
2280 if (XINT (x, i) != XINT (y, i))
2281 return 0;
2282 break;
2284 case 'e':
2285 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2286 if (val == 0)
2287 return 0;
2288 /* If any subexpression returns 2,
2289 we should return 2 if we are successful. */
2290 if (val == 2)
2291 success_2 = 1;
2292 break;
2294 case '0':
2295 break;
2297 case 'E':
2298 if (XVECLEN (x, i) != XVECLEN (y, i))
2299 return 0;
2300 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2302 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2303 if (val == 0)
2304 return 0;
2305 if (val == 2)
2306 success_2 = 1;
2308 break;
2310 /* It is believed that rtx's at this level will never
2311 contain anything but integers and other rtx's,
2312 except for within LABEL_REFs and SYMBOL_REFs. */
2313 default:
2314 gcc_unreachable ();
2317 return 1 + success_2;
2320 /* Describe the range of registers or memory referenced by X.
2321 If X is a register, set REG_FLAG and put the first register
2322 number into START and the last plus one into END.
2323 If X is a memory reference, put a base address into BASE
2324 and a range of integer offsets into START and END.
2325 If X is pushing on the stack, we can assume it causes no trouble,
2326 so we set the SAFE field. */
2328 static struct decomposition
2329 decompose (rtx x)
2331 struct decomposition val;
2332 int all_const = 0;
2334 memset (&val, 0, sizeof (val));
2336 switch (GET_CODE (x))
2338 case MEM:
2340 rtx base = NULL_RTX, offset = 0;
2341 rtx addr = XEXP (x, 0);
2343 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2344 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2346 val.base = XEXP (addr, 0);
2347 val.start = -GET_MODE_SIZE (GET_MODE (x));
2348 val.end = GET_MODE_SIZE (GET_MODE (x));
2349 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2350 return val;
2353 if (GET_CODE (addr) == PRE_MODIFY || GET_CODE (addr) == POST_MODIFY)
2355 if (GET_CODE (XEXP (addr, 1)) == PLUS
2356 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
2357 && CONSTANT_P (XEXP (XEXP (addr, 1), 1)))
2359 val.base = XEXP (addr, 0);
2360 val.start = -INTVAL (XEXP (XEXP (addr, 1), 1));
2361 val.end = INTVAL (XEXP (XEXP (addr, 1), 1));
2362 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2363 return val;
2367 if (GET_CODE (addr) == CONST)
2369 addr = XEXP (addr, 0);
2370 all_const = 1;
2372 if (GET_CODE (addr) == PLUS)
2374 if (CONSTANT_P (XEXP (addr, 0)))
2376 base = XEXP (addr, 1);
2377 offset = XEXP (addr, 0);
2379 else if (CONSTANT_P (XEXP (addr, 1)))
2381 base = XEXP (addr, 0);
2382 offset = XEXP (addr, 1);
2386 if (offset == 0)
2388 base = addr;
2389 offset = const0_rtx;
2391 if (GET_CODE (offset) == CONST)
2392 offset = XEXP (offset, 0);
2393 if (GET_CODE (offset) == PLUS)
2395 if (GET_CODE (XEXP (offset, 0)) == CONST_INT)
2397 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2398 offset = XEXP (offset, 0);
2400 else if (GET_CODE (XEXP (offset, 1)) == CONST_INT)
2402 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2403 offset = XEXP (offset, 1);
2405 else
2407 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2408 offset = const0_rtx;
2411 else if (GET_CODE (offset) != CONST_INT)
2413 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2414 offset = const0_rtx;
2417 if (all_const && GET_CODE (base) == PLUS)
2418 base = gen_rtx_CONST (GET_MODE (base), base);
2420 gcc_assert (GET_CODE (offset) == CONST_INT);
2422 val.start = INTVAL (offset);
2423 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2424 val.base = base;
2426 break;
2428 case REG:
2429 val.reg_flag = 1;
2430 val.start = true_regnum (x);
2431 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2433 /* A pseudo with no hard reg. */
2434 val.start = REGNO (x);
2435 val.end = val.start + 1;
2437 else
2438 /* A hard reg. */
2439 val.end = end_hard_regno (GET_MODE (x), val.start);
2440 break;
2442 case SUBREG:
2443 if (!REG_P (SUBREG_REG (x)))
2444 /* This could be more precise, but it's good enough. */
2445 return decompose (SUBREG_REG (x));
2446 val.reg_flag = 1;
2447 val.start = true_regnum (x);
2448 if (val.start < 0 || val.start >= FIRST_PSEUDO_REGISTER)
2449 return decompose (SUBREG_REG (x));
2450 else
2451 /* A hard reg. */
2452 val.end = val.start + subreg_nregs (x);
2453 break;
2455 case SCRATCH:
2456 /* This hasn't been assigned yet, so it can't conflict yet. */
2457 val.safe = 1;
2458 break;
2460 default:
2461 gcc_assert (CONSTANT_P (x));
2462 val.safe = 1;
2463 break;
2465 return val;
2468 /* Return 1 if altering Y will not modify the value of X.
2469 Y is also described by YDATA, which should be decompose (Y). */
2471 static int
2472 immune_p (rtx x, rtx y, struct decomposition ydata)
2474 struct decomposition xdata;
2476 if (ydata.reg_flag)
2477 return !refers_to_regno_for_reload_p (ydata.start, ydata.end, x, (rtx*) 0);
2478 if (ydata.safe)
2479 return 1;
2481 gcc_assert (MEM_P (y));
2482 /* If Y is memory and X is not, Y can't affect X. */
2483 if (!MEM_P (x))
2484 return 1;
2486 xdata = decompose (x);
2488 if (! rtx_equal_p (xdata.base, ydata.base))
2490 /* If bases are distinct symbolic constants, there is no overlap. */
2491 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2492 return 1;
2493 /* Constants and stack slots never overlap. */
2494 if (CONSTANT_P (xdata.base)
2495 && (ydata.base == frame_pointer_rtx
2496 || ydata.base == hard_frame_pointer_rtx
2497 || ydata.base == stack_pointer_rtx))
2498 return 1;
2499 if (CONSTANT_P (ydata.base)
2500 && (xdata.base == frame_pointer_rtx
2501 || xdata.base == hard_frame_pointer_rtx
2502 || xdata.base == stack_pointer_rtx))
2503 return 1;
2504 /* If either base is variable, we don't know anything. */
2505 return 0;
2508 return (xdata.start >= ydata.end || ydata.start >= xdata.end);
2511 /* Similar, but calls decompose. */
2514 safe_from_earlyclobber (rtx op, rtx clobber)
2516 struct decomposition early_data;
2518 early_data = decompose (clobber);
2519 return immune_p (op, clobber, early_data);
2522 /* Main entry point of this file: search the body of INSN
2523 for values that need reloading and record them with push_reload.
2524 REPLACE nonzero means record also where the values occur
2525 so that subst_reloads can be used.
2527 IND_LEVELS says how many levels of indirection are supported by this
2528 machine; a value of zero means that a memory reference is not a valid
2529 memory address.
2531 LIVE_KNOWN says we have valid information about which hard
2532 regs are live at each point in the program; this is true when
2533 we are called from global_alloc but false when stupid register
2534 allocation has been done.
2536 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2537 which is nonnegative if the reg has been commandeered for reloading into.
2538 It is copied into STATIC_RELOAD_REG_P and referenced from there
2539 by various subroutines.
2541 Return TRUE if some operands need to be changed, because of swapping
2542 commutative operands, reg_equiv_address substitution, or whatever. */
2545 find_reloads (rtx insn, int replace, int ind_levels, int live_known,
2546 short *reload_reg_p)
2548 int insn_code_number;
2549 int i, j;
2550 int noperands;
2551 /* These start out as the constraints for the insn
2552 and they are chewed up as we consider alternatives. */
2553 const char *constraints[MAX_RECOG_OPERANDS];
2554 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2555 a register. */
2556 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2557 char pref_or_nothing[MAX_RECOG_OPERANDS];
2558 /* Nonzero for a MEM operand whose entire address needs a reload.
2559 May be -1 to indicate the entire address may or may not need a reload. */
2560 int address_reloaded[MAX_RECOG_OPERANDS];
2561 /* Nonzero for an address operand that needs to be completely reloaded.
2562 May be -1 to indicate the entire operand may or may not need a reload. */
2563 int address_operand_reloaded[MAX_RECOG_OPERANDS];
2564 /* Value of enum reload_type to use for operand. */
2565 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2566 /* Value of enum reload_type to use within address of operand. */
2567 enum reload_type address_type[MAX_RECOG_OPERANDS];
2568 /* Save the usage of each operand. */
2569 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2570 int no_input_reloads = 0, no_output_reloads = 0;
2571 int n_alternatives;
2572 int this_alternative[MAX_RECOG_OPERANDS];
2573 char this_alternative_match_win[MAX_RECOG_OPERANDS];
2574 char this_alternative_win[MAX_RECOG_OPERANDS];
2575 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2576 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2577 int this_alternative_matches[MAX_RECOG_OPERANDS];
2578 int swapped;
2579 int goal_alternative[MAX_RECOG_OPERANDS];
2580 int this_alternative_number;
2581 int goal_alternative_number = 0;
2582 int operand_reloadnum[MAX_RECOG_OPERANDS];
2583 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2584 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2585 char goal_alternative_match_win[MAX_RECOG_OPERANDS];
2586 char goal_alternative_win[MAX_RECOG_OPERANDS];
2587 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2588 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2589 int goal_alternative_swapped;
2590 int best;
2591 int commutative;
2592 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2593 rtx substed_operand[MAX_RECOG_OPERANDS];
2594 rtx body = PATTERN (insn);
2595 rtx set = single_set (insn);
2596 int goal_earlyclobber = 0, this_earlyclobber;
2597 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
2598 int retval = 0;
2600 this_insn = insn;
2601 n_reloads = 0;
2602 n_replacements = 0;
2603 n_earlyclobbers = 0;
2604 replace_reloads = replace;
2605 hard_regs_live_known = live_known;
2606 static_reload_reg_p = reload_reg_p;
2608 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads;
2609 neither are insns that SET cc0. Insns that use CC0 are not allowed
2610 to have any input reloads. */
2611 if (JUMP_P (insn) || CALL_P (insn))
2612 no_output_reloads = 1;
2614 #ifdef HAVE_cc0
2615 if (reg_referenced_p (cc0_rtx, PATTERN (insn)))
2616 no_input_reloads = 1;
2617 if (reg_set_p (cc0_rtx, PATTERN (insn)))
2618 no_output_reloads = 1;
2619 #endif
2621 #ifdef SECONDARY_MEMORY_NEEDED
2622 /* The eliminated forms of any secondary memory locations are per-insn, so
2623 clear them out here. */
2625 if (secondary_memlocs_elim_used)
2627 memset (secondary_memlocs_elim, 0,
2628 sizeof (secondary_memlocs_elim[0]) * secondary_memlocs_elim_used);
2629 secondary_memlocs_elim_used = 0;
2631 #endif
2633 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2634 is cheap to move between them. If it is not, there may not be an insn
2635 to do the copy, so we may need a reload. */
2636 if (GET_CODE (body) == SET
2637 && REG_P (SET_DEST (body))
2638 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2639 && REG_P (SET_SRC (body))
2640 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2641 && REGISTER_MOVE_COST (GET_MODE (SET_SRC (body)),
2642 REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2643 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2644 return 0;
2646 extract_insn (insn);
2648 noperands = reload_n_operands = recog_data.n_operands;
2649 n_alternatives = recog_data.n_alternatives;
2651 /* Just return "no reloads" if insn has no operands with constraints. */
2652 if (noperands == 0 || n_alternatives == 0)
2653 return 0;
2655 insn_code_number = INSN_CODE (insn);
2656 this_insn_is_asm = insn_code_number < 0;
2658 memcpy (operand_mode, recog_data.operand_mode,
2659 noperands * sizeof (enum machine_mode));
2660 memcpy (constraints, recog_data.constraints,
2661 noperands * sizeof (const char *));
2663 commutative = -1;
2665 /* If we will need to know, later, whether some pair of operands
2666 are the same, we must compare them now and save the result.
2667 Reloading the base and index registers will clobber them
2668 and afterward they will fail to match. */
2670 for (i = 0; i < noperands; i++)
2672 const char *p;
2673 int c;
2674 char *end;
2676 substed_operand[i] = recog_data.operand[i];
2677 p = constraints[i];
2679 modified[i] = RELOAD_READ;
2681 /* Scan this operand's constraint to see if it is an output operand,
2682 an in-out operand, is commutative, or should match another. */
2684 while ((c = *p))
2686 p += CONSTRAINT_LEN (c, p);
2687 switch (c)
2689 case '=':
2690 modified[i] = RELOAD_WRITE;
2691 break;
2692 case '+':
2693 modified[i] = RELOAD_READ_WRITE;
2694 break;
2695 case '%':
2697 /* The last operand should not be marked commutative. */
2698 gcc_assert (i != noperands - 1);
2700 /* We currently only support one commutative pair of
2701 operands. Some existing asm code currently uses more
2702 than one pair. Previously, that would usually work,
2703 but sometimes it would crash the compiler. We
2704 continue supporting that case as well as we can by
2705 silently ignoring all but the first pair. In the
2706 future we may handle it correctly. */
2707 if (commutative < 0)
2708 commutative = i;
2709 else
2710 gcc_assert (this_insn_is_asm);
2712 break;
2713 /* Use of ISDIGIT is tempting here, but it may get expensive because
2714 of locale support we don't want. */
2715 case '0': case '1': case '2': case '3': case '4':
2716 case '5': case '6': case '7': case '8': case '9':
2718 c = strtoul (p - 1, &end, 10);
2719 p = end;
2721 operands_match[c][i]
2722 = operands_match_p (recog_data.operand[c],
2723 recog_data.operand[i]);
2725 /* An operand may not match itself. */
2726 gcc_assert (c != i);
2728 /* If C can be commuted with C+1, and C might need to match I,
2729 then C+1 might also need to match I. */
2730 if (commutative >= 0)
2732 if (c == commutative || c == commutative + 1)
2734 int other = c + (c == commutative ? 1 : -1);
2735 operands_match[other][i]
2736 = operands_match_p (recog_data.operand[other],
2737 recog_data.operand[i]);
2739 if (i == commutative || i == commutative + 1)
2741 int other = i + (i == commutative ? 1 : -1);
2742 operands_match[c][other]
2743 = operands_match_p (recog_data.operand[c],
2744 recog_data.operand[other]);
2746 /* Note that C is supposed to be less than I.
2747 No need to consider altering both C and I because in
2748 that case we would alter one into the other. */
2755 /* Examine each operand that is a memory reference or memory address
2756 and reload parts of the addresses into index registers.
2757 Also here any references to pseudo regs that didn't get hard regs
2758 but are equivalent to constants get replaced in the insn itself
2759 with those constants. Nobody will ever see them again.
2761 Finally, set up the preferred classes of each operand. */
2763 for (i = 0; i < noperands; i++)
2765 RTX_CODE code = GET_CODE (recog_data.operand[i]);
2767 address_reloaded[i] = 0;
2768 address_operand_reloaded[i] = 0;
2769 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2770 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2771 : RELOAD_OTHER);
2772 address_type[i]
2773 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2774 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2775 : RELOAD_OTHER);
2777 if (*constraints[i] == 0)
2778 /* Ignore things like match_operator operands. */
2780 else if (constraints[i][0] == 'p'
2781 || EXTRA_ADDRESS_CONSTRAINT (constraints[i][0], constraints[i]))
2783 address_operand_reloaded[i]
2784 = find_reloads_address (recog_data.operand_mode[i], (rtx*) 0,
2785 recog_data.operand[i],
2786 recog_data.operand_loc[i],
2787 i, operand_type[i], ind_levels, insn);
2789 /* If we now have a simple operand where we used to have a
2790 PLUS or MULT, re-recognize and try again. */
2791 if ((OBJECT_P (*recog_data.operand_loc[i])
2792 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2793 && (GET_CODE (recog_data.operand[i]) == MULT
2794 || GET_CODE (recog_data.operand[i]) == PLUS))
2796 INSN_CODE (insn) = -1;
2797 retval = find_reloads (insn, replace, ind_levels, live_known,
2798 reload_reg_p);
2799 return retval;
2802 recog_data.operand[i] = *recog_data.operand_loc[i];
2803 substed_operand[i] = recog_data.operand[i];
2805 /* Address operands are reloaded in their existing mode,
2806 no matter what is specified in the machine description. */
2807 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2809 else if (code == MEM)
2811 address_reloaded[i]
2812 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2813 recog_data.operand_loc[i],
2814 XEXP (recog_data.operand[i], 0),
2815 &XEXP (recog_data.operand[i], 0),
2816 i, address_type[i], ind_levels, insn);
2817 recog_data.operand[i] = *recog_data.operand_loc[i];
2818 substed_operand[i] = recog_data.operand[i];
2820 else if (code == SUBREG)
2822 rtx reg = SUBREG_REG (recog_data.operand[i]);
2823 rtx op
2824 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2825 ind_levels,
2826 set != 0
2827 && &SET_DEST (set) == recog_data.operand_loc[i],
2828 insn,
2829 &address_reloaded[i]);
2831 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2832 that didn't get a hard register, emit a USE with a REG_EQUAL
2833 note in front so that we might inherit a previous, possibly
2834 wider reload. */
2836 if (replace
2837 && MEM_P (op)
2838 && REG_P (reg)
2839 && (GET_MODE_SIZE (GET_MODE (reg))
2840 >= GET_MODE_SIZE (GET_MODE (op)))
2841 && reg_equiv_constant[REGNO (reg)] == 0)
2842 set_unique_reg_note (emit_insn_before (gen_rtx_USE (VOIDmode, reg),
2843 insn),
2844 REG_EQUAL, reg_equiv_memory_loc[REGNO (reg)]);
2846 substed_operand[i] = recog_data.operand[i] = op;
2848 else if (code == PLUS || GET_RTX_CLASS (code) == RTX_UNARY)
2849 /* We can get a PLUS as an "operand" as a result of register
2850 elimination. See eliminate_regs and gen_reload. We handle
2851 a unary operator by reloading the operand. */
2852 substed_operand[i] = recog_data.operand[i]
2853 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2854 ind_levels, 0, insn,
2855 &address_reloaded[i]);
2856 else if (code == REG)
2858 /* This is equivalent to calling find_reloads_toplev.
2859 The code is duplicated for speed.
2860 When we find a pseudo always equivalent to a constant,
2861 we replace it by the constant. We must be sure, however,
2862 that we don't try to replace it in the insn in which it
2863 is being set. */
2864 int regno = REGNO (recog_data.operand[i]);
2865 if (reg_equiv_constant[regno] != 0
2866 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2868 /* Record the existing mode so that the check if constants are
2869 allowed will work when operand_mode isn't specified. */
2871 if (operand_mode[i] == VOIDmode)
2872 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2874 substed_operand[i] = recog_data.operand[i]
2875 = reg_equiv_constant[regno];
2877 if (reg_equiv_memory_loc[regno] != 0
2878 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
2879 /* We need not give a valid is_set_dest argument since the case
2880 of a constant equivalence was checked above. */
2881 substed_operand[i] = recog_data.operand[i]
2882 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2883 ind_levels, 0, insn,
2884 &address_reloaded[i]);
2886 /* If the operand is still a register (we didn't replace it with an
2887 equivalent), get the preferred class to reload it into. */
2888 code = GET_CODE (recog_data.operand[i]);
2889 preferred_class[i]
2890 = ((code == REG && REGNO (recog_data.operand[i])
2891 >= FIRST_PSEUDO_REGISTER)
2892 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2893 : NO_REGS);
2894 pref_or_nothing[i]
2895 = (code == REG
2896 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2897 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2900 /* If this is simply a copy from operand 1 to operand 0, merge the
2901 preferred classes for the operands. */
2902 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2903 && recog_data.operand[1] == SET_SRC (set))
2905 preferred_class[0] = preferred_class[1]
2906 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2907 pref_or_nothing[0] |= pref_or_nothing[1];
2908 pref_or_nothing[1] |= pref_or_nothing[0];
2911 /* Now see what we need for pseudo-regs that didn't get hard regs
2912 or got the wrong kind of hard reg. For this, we must consider
2913 all the operands together against the register constraints. */
2915 best = MAX_RECOG_OPERANDS * 2 + 600;
2917 swapped = 0;
2918 goal_alternative_swapped = 0;
2919 try_swapped:
2921 /* The constraints are made of several alternatives.
2922 Each operand's constraint looks like foo,bar,... with commas
2923 separating the alternatives. The first alternatives for all
2924 operands go together, the second alternatives go together, etc.
2926 First loop over alternatives. */
2928 for (this_alternative_number = 0;
2929 this_alternative_number < n_alternatives;
2930 this_alternative_number++)
2932 /* Loop over operands for one constraint alternative. */
2933 /* LOSERS counts those that don't fit this alternative
2934 and would require loading. */
2935 int losers = 0;
2936 /* BAD is set to 1 if it some operand can't fit this alternative
2937 even after reloading. */
2938 int bad = 0;
2939 /* REJECT is a count of how undesirable this alternative says it is
2940 if any reloading is required. If the alternative matches exactly
2941 then REJECT is ignored, but otherwise it gets this much
2942 counted against it in addition to the reloading needed. Each
2943 ? counts three times here since we want the disparaging caused by
2944 a bad register class to only count 1/3 as much. */
2945 int reject = 0;
2947 if (!recog_data.alternative_enabled_p[this_alternative_number])
2949 int i;
2951 for (i = 0; i < recog_data.n_operands; i++)
2952 constraints[i] = skip_alternative (constraints[i]);
2954 continue;
2957 this_earlyclobber = 0;
2959 for (i = 0; i < noperands; i++)
2961 const char *p = constraints[i];
2962 char *end;
2963 int len;
2964 int win = 0;
2965 int did_match = 0;
2966 /* 0 => this operand can be reloaded somehow for this alternative. */
2967 int badop = 1;
2968 /* 0 => this operand can be reloaded if the alternative allows regs. */
2969 int winreg = 0;
2970 int c;
2971 int m;
2972 rtx operand = recog_data.operand[i];
2973 int offset = 0;
2974 /* Nonzero means this is a MEM that must be reloaded into a reg
2975 regardless of what the constraint says. */
2976 int force_reload = 0;
2977 int offmemok = 0;
2978 /* Nonzero if a constant forced into memory would be OK for this
2979 operand. */
2980 int constmemok = 0;
2981 int earlyclobber = 0;
2983 /* If the predicate accepts a unary operator, it means that
2984 we need to reload the operand, but do not do this for
2985 match_operator and friends. */
2986 if (UNARY_P (operand) && *p != 0)
2987 operand = XEXP (operand, 0);
2989 /* If the operand is a SUBREG, extract
2990 the REG or MEM (or maybe even a constant) within.
2991 (Constants can occur as a result of reg_equiv_constant.) */
2993 while (GET_CODE (operand) == SUBREG)
2995 /* Offset only matters when operand is a REG and
2996 it is a hard reg. This is because it is passed
2997 to reg_fits_class_p if it is a REG and all pseudos
2998 return 0 from that function. */
2999 if (REG_P (SUBREG_REG (operand))
3000 && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
3002 if (simplify_subreg_regno (REGNO (SUBREG_REG (operand)),
3003 GET_MODE (SUBREG_REG (operand)),
3004 SUBREG_BYTE (operand),
3005 GET_MODE (operand)) < 0)
3006 force_reload = 1;
3007 offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
3008 GET_MODE (SUBREG_REG (operand)),
3009 SUBREG_BYTE (operand),
3010 GET_MODE (operand));
3012 operand = SUBREG_REG (operand);
3013 /* Force reload if this is a constant or PLUS or if there may
3014 be a problem accessing OPERAND in the outer mode. */
3015 if (CONSTANT_P (operand)
3016 || GET_CODE (operand) == PLUS
3017 /* We must force a reload of paradoxical SUBREGs
3018 of a MEM because the alignment of the inner value
3019 may not be enough to do the outer reference. On
3020 big-endian machines, it may also reference outside
3021 the object.
3023 On machines that extend byte operations and we have a
3024 SUBREG where both the inner and outer modes are no wider
3025 than a word and the inner mode is narrower, is integral,
3026 and gets extended when loaded from memory, combine.c has
3027 made assumptions about the behavior of the machine in such
3028 register access. If the data is, in fact, in memory we
3029 must always load using the size assumed to be in the
3030 register and let the insn do the different-sized
3031 accesses.
3033 This is doubly true if WORD_REGISTER_OPERATIONS. In
3034 this case eliminate_regs has left non-paradoxical
3035 subregs for push_reload to see. Make sure it does
3036 by forcing the reload.
3038 ??? When is it right at this stage to have a subreg
3039 of a mem that is _not_ to be handled specially? IMO
3040 those should have been reduced to just a mem. */
3041 || ((MEM_P (operand)
3042 || (REG_P (operand)
3043 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3044 #ifndef WORD_REGISTER_OPERATIONS
3045 && (((GET_MODE_BITSIZE (GET_MODE (operand))
3046 < BIGGEST_ALIGNMENT)
3047 && (GET_MODE_SIZE (operand_mode[i])
3048 > GET_MODE_SIZE (GET_MODE (operand))))
3049 || BYTES_BIG_ENDIAN
3050 #ifdef LOAD_EXTEND_OP
3051 || (GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3052 && (GET_MODE_SIZE (GET_MODE (operand))
3053 <= UNITS_PER_WORD)
3054 && (GET_MODE_SIZE (operand_mode[i])
3055 > GET_MODE_SIZE (GET_MODE (operand)))
3056 && INTEGRAL_MODE_P (GET_MODE (operand))
3057 && LOAD_EXTEND_OP (GET_MODE (operand)) != UNKNOWN)
3058 #endif
3060 #endif
3063 force_reload = 1;
3066 this_alternative[i] = (int) NO_REGS;
3067 this_alternative_win[i] = 0;
3068 this_alternative_match_win[i] = 0;
3069 this_alternative_offmemok[i] = 0;
3070 this_alternative_earlyclobber[i] = 0;
3071 this_alternative_matches[i] = -1;
3073 /* An empty constraint or empty alternative
3074 allows anything which matched the pattern. */
3075 if (*p == 0 || *p == ',')
3076 win = 1, badop = 0;
3078 /* Scan this alternative's specs for this operand;
3079 set WIN if the operand fits any letter in this alternative.
3080 Otherwise, clear BADOP if this operand could
3081 fit some letter after reloads,
3082 or set WINREG if this operand could fit after reloads
3083 provided the constraint allows some registers. */
3086 switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
3088 case '\0':
3089 len = 0;
3090 break;
3091 case ',':
3092 c = '\0';
3093 break;
3095 case '=': case '+': case '*':
3096 break;
3098 case '%':
3099 /* We only support one commutative marker, the first
3100 one. We already set commutative above. */
3101 break;
3103 case '?':
3104 reject += 6;
3105 break;
3107 case '!':
3108 reject = 600;
3109 break;
3111 case '#':
3112 /* Ignore rest of this alternative as far as
3113 reloading is concerned. */
3115 p++;
3116 while (*p && *p != ',');
3117 len = 0;
3118 break;
3120 case '0': case '1': case '2': case '3': case '4':
3121 case '5': case '6': case '7': case '8': case '9':
3122 m = strtoul (p, &end, 10);
3123 p = end;
3124 len = 0;
3126 this_alternative_matches[i] = m;
3127 /* We are supposed to match a previous operand.
3128 If we do, we win if that one did.
3129 If we do not, count both of the operands as losers.
3130 (This is too conservative, since most of the time
3131 only a single reload insn will be needed to make
3132 the two operands win. As a result, this alternative
3133 may be rejected when it is actually desirable.) */
3134 if ((swapped && (m != commutative || i != commutative + 1))
3135 /* If we are matching as if two operands were swapped,
3136 also pretend that operands_match had been computed
3137 with swapped.
3138 But if I is the second of those and C is the first,
3139 don't exchange them, because operands_match is valid
3140 only on one side of its diagonal. */
3141 ? (operands_match
3142 [(m == commutative || m == commutative + 1)
3143 ? 2 * commutative + 1 - m : m]
3144 [(i == commutative || i == commutative + 1)
3145 ? 2 * commutative + 1 - i : i])
3146 : operands_match[m][i])
3148 /* If we are matching a non-offsettable address where an
3149 offsettable address was expected, then we must reject
3150 this combination, because we can't reload it. */
3151 if (this_alternative_offmemok[m]
3152 && MEM_P (recog_data.operand[m])
3153 && this_alternative[m] == (int) NO_REGS
3154 && ! this_alternative_win[m])
3155 bad = 1;
3157 did_match = this_alternative_win[m];
3159 else
3161 /* Operands don't match. */
3162 rtx value;
3163 int loc1, loc2;
3164 /* Retroactively mark the operand we had to match
3165 as a loser, if it wasn't already. */
3166 if (this_alternative_win[m])
3167 losers++;
3168 this_alternative_win[m] = 0;
3169 if (this_alternative[m] == (int) NO_REGS)
3170 bad = 1;
3171 /* But count the pair only once in the total badness of
3172 this alternative, if the pair can be a dummy reload.
3173 The pointers in operand_loc are not swapped; swap
3174 them by hand if necessary. */
3175 if (swapped && i == commutative)
3176 loc1 = commutative + 1;
3177 else if (swapped && i == commutative + 1)
3178 loc1 = commutative;
3179 else
3180 loc1 = i;
3181 if (swapped && m == commutative)
3182 loc2 = commutative + 1;
3183 else if (swapped && m == commutative + 1)
3184 loc2 = commutative;
3185 else
3186 loc2 = m;
3187 value
3188 = find_dummy_reload (recog_data.operand[i],
3189 recog_data.operand[m],
3190 recog_data.operand_loc[loc1],
3191 recog_data.operand_loc[loc2],
3192 operand_mode[i], operand_mode[m],
3193 this_alternative[m], -1,
3194 this_alternative_earlyclobber[m]);
3196 if (value != 0)
3197 losers--;
3199 /* This can be fixed with reloads if the operand
3200 we are supposed to match can be fixed with reloads. */
3201 badop = 0;
3202 this_alternative[i] = this_alternative[m];
3204 /* If we have to reload this operand and some previous
3205 operand also had to match the same thing as this
3206 operand, we don't know how to do that. So reject this
3207 alternative. */
3208 if (! did_match || force_reload)
3209 for (j = 0; j < i; j++)
3210 if (this_alternative_matches[j]
3211 == this_alternative_matches[i])
3212 badop = 1;
3213 break;
3215 case 'p':
3216 /* All necessary reloads for an address_operand
3217 were handled in find_reloads_address. */
3218 this_alternative[i]
3219 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3220 win = 1;
3221 badop = 0;
3222 break;
3224 case TARGET_MEM_CONSTRAINT:
3225 if (force_reload)
3226 break;
3227 if (MEM_P (operand)
3228 || (REG_P (operand)
3229 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3230 && reg_renumber[REGNO (operand)] < 0))
3231 win = 1;
3232 if (CONST_POOL_OK_P (operand))
3233 badop = 0;
3234 constmemok = 1;
3235 break;
3237 case '<':
3238 if (MEM_P (operand)
3239 && ! address_reloaded[i]
3240 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
3241 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
3242 win = 1;
3243 break;
3245 case '>':
3246 if (MEM_P (operand)
3247 && ! address_reloaded[i]
3248 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
3249 || GET_CODE (XEXP (operand, 0)) == POST_INC))
3250 win = 1;
3251 break;
3253 /* Memory operand whose address is not offsettable. */
3254 case 'V':
3255 if (force_reload)
3256 break;
3257 if (MEM_P (operand)
3258 && ! (ind_levels ? offsettable_memref_p (operand)
3259 : offsettable_nonstrict_memref_p (operand))
3260 /* Certain mem addresses will become offsettable
3261 after they themselves are reloaded. This is important;
3262 we don't want our own handling of unoffsettables
3263 to override the handling of reg_equiv_address. */
3264 && !(REG_P (XEXP (operand, 0))
3265 && (ind_levels == 0
3266 || reg_equiv_address[REGNO (XEXP (operand, 0))] != 0)))
3267 win = 1;
3268 break;
3270 /* Memory operand whose address is offsettable. */
3271 case 'o':
3272 if (force_reload)
3273 break;
3274 if ((MEM_P (operand)
3275 /* If IND_LEVELS, find_reloads_address won't reload a
3276 pseudo that didn't get a hard reg, so we have to
3277 reject that case. */
3278 && ((ind_levels ? offsettable_memref_p (operand)
3279 : offsettable_nonstrict_memref_p (operand))
3280 /* A reloaded address is offsettable because it is now
3281 just a simple register indirect. */
3282 || address_reloaded[i] == 1))
3283 || (REG_P (operand)
3284 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3285 && reg_renumber[REGNO (operand)] < 0
3286 /* If reg_equiv_address is nonzero, we will be
3287 loading it into a register; hence it will be
3288 offsettable, but we cannot say that reg_equiv_mem
3289 is offsettable without checking. */
3290 && ((reg_equiv_mem[REGNO (operand)] != 0
3291 && offsettable_memref_p (reg_equiv_mem[REGNO (operand)]))
3292 || (reg_equiv_address[REGNO (operand)] != 0))))
3293 win = 1;
3294 if (CONST_POOL_OK_P (operand)
3295 || MEM_P (operand))
3296 badop = 0;
3297 constmemok = 1;
3298 offmemok = 1;
3299 break;
3301 case '&':
3302 /* Output operand that is stored before the need for the
3303 input operands (and their index registers) is over. */
3304 earlyclobber = 1, this_earlyclobber = 1;
3305 break;
3307 case 'E':
3308 case 'F':
3309 if (GET_CODE (operand) == CONST_DOUBLE
3310 || (GET_CODE (operand) == CONST_VECTOR
3311 && (GET_MODE_CLASS (GET_MODE (operand))
3312 == MODE_VECTOR_FLOAT)))
3313 win = 1;
3314 break;
3316 case 'G':
3317 case 'H':
3318 if (GET_CODE (operand) == CONST_DOUBLE
3319 && CONST_DOUBLE_OK_FOR_CONSTRAINT_P (operand, c, p))
3320 win = 1;
3321 break;
3323 case 's':
3324 if (GET_CODE (operand) == CONST_INT
3325 || (GET_CODE (operand) == CONST_DOUBLE
3326 && GET_MODE (operand) == VOIDmode))
3327 break;
3328 case 'i':
3329 if (CONSTANT_P (operand)
3330 && (! flag_pic || LEGITIMATE_PIC_OPERAND_P (operand)))
3331 win = 1;
3332 break;
3334 case 'n':
3335 if (GET_CODE (operand) == CONST_INT
3336 || (GET_CODE (operand) == CONST_DOUBLE
3337 && GET_MODE (operand) == VOIDmode))
3338 win = 1;
3339 break;
3341 case 'I':
3342 case 'J':
3343 case 'K':
3344 case 'L':
3345 case 'M':
3346 case 'N':
3347 case 'O':
3348 case 'P':
3349 if (GET_CODE (operand) == CONST_INT
3350 && CONST_OK_FOR_CONSTRAINT_P (INTVAL (operand), c, p))
3351 win = 1;
3352 break;
3354 case 'X':
3355 force_reload = 0;
3356 win = 1;
3357 break;
3359 case 'g':
3360 if (! force_reload
3361 /* A PLUS is never a valid operand, but reload can make
3362 it from a register when eliminating registers. */
3363 && GET_CODE (operand) != PLUS
3364 /* A SCRATCH is not a valid operand. */
3365 && GET_CODE (operand) != SCRATCH
3366 && (! CONSTANT_P (operand)
3367 || ! flag_pic
3368 || LEGITIMATE_PIC_OPERAND_P (operand))
3369 && (GENERAL_REGS == ALL_REGS
3370 || !REG_P (operand)
3371 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3372 && reg_renumber[REGNO (operand)] < 0)))
3373 win = 1;
3374 /* Drop through into 'r' case. */
3376 case 'r':
3377 this_alternative[i]
3378 = (int) reg_class_subunion[this_alternative[i]][(int) GENERAL_REGS];
3379 goto reg;
3381 default:
3382 if (REG_CLASS_FROM_CONSTRAINT (c, p) == NO_REGS)
3384 #ifdef EXTRA_CONSTRAINT_STR
3385 if (EXTRA_MEMORY_CONSTRAINT (c, p))
3387 if (force_reload)
3388 break;
3389 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3390 win = 1;
3391 /* If the address was already reloaded,
3392 we win as well. */
3393 else if (MEM_P (operand)
3394 && address_reloaded[i] == 1)
3395 win = 1;
3396 /* Likewise if the address will be reloaded because
3397 reg_equiv_address is nonzero. For reg_equiv_mem
3398 we have to check. */
3399 else if (REG_P (operand)
3400 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3401 && reg_renumber[REGNO (operand)] < 0
3402 && ((reg_equiv_mem[REGNO (operand)] != 0
3403 && EXTRA_CONSTRAINT_STR (reg_equiv_mem[REGNO (operand)], c, p))
3404 || (reg_equiv_address[REGNO (operand)] != 0)))
3405 win = 1;
3407 /* If we didn't already win, we can reload
3408 constants via force_const_mem, and other
3409 MEMs by reloading the address like for 'o'. */
3410 if (CONST_POOL_OK_P (operand)
3411 || MEM_P (operand))
3412 badop = 0;
3413 constmemok = 1;
3414 offmemok = 1;
3415 break;
3417 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
3419 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3420 win = 1;
3422 /* If we didn't already win, we can reload
3423 the address into a base register. */
3424 this_alternative[i]
3425 = (int) base_reg_class (VOIDmode, ADDRESS, SCRATCH);
3426 badop = 0;
3427 break;
3430 if (EXTRA_CONSTRAINT_STR (operand, c, p))
3431 win = 1;
3432 #endif
3433 break;
3436 this_alternative[i]
3437 = (int) (reg_class_subunion
3438 [this_alternative[i]]
3439 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)]);
3440 reg:
3441 if (GET_MODE (operand) == BLKmode)
3442 break;
3443 winreg = 1;
3444 if (REG_P (operand)
3445 && reg_fits_class_p (operand, this_alternative[i],
3446 offset, GET_MODE (recog_data.operand[i])))
3447 win = 1;
3448 break;
3450 while ((p += len), c);
3452 constraints[i] = p;
3454 /* If this operand could be handled with a reg,
3455 and some reg is allowed, then this operand can be handled. */
3456 if (winreg && this_alternative[i] != (int) NO_REGS)
3457 badop = 0;
3459 /* Record which operands fit this alternative. */
3460 this_alternative_earlyclobber[i] = earlyclobber;
3461 if (win && ! force_reload)
3462 this_alternative_win[i] = 1;
3463 else if (did_match && ! force_reload)
3464 this_alternative_match_win[i] = 1;
3465 else
3467 int const_to_mem = 0;
3469 this_alternative_offmemok[i] = offmemok;
3470 losers++;
3471 if (badop)
3472 bad = 1;
3473 /* Alternative loses if it has no regs for a reg operand. */
3474 if (REG_P (operand)
3475 && this_alternative[i] == (int) NO_REGS
3476 && this_alternative_matches[i] < 0)
3477 bad = 1;
3479 /* If this is a constant that is reloaded into the desired
3480 class by copying it to memory first, count that as another
3481 reload. This is consistent with other code and is
3482 required to avoid choosing another alternative when
3483 the constant is moved into memory by this function on
3484 an early reload pass. Note that the test here is
3485 precisely the same as in the code below that calls
3486 force_const_mem. */
3487 if (CONST_POOL_OK_P (operand)
3488 && ((PREFERRED_RELOAD_CLASS (operand,
3489 (enum reg_class) this_alternative[i])
3490 == NO_REGS)
3491 || no_input_reloads)
3492 && operand_mode[i] != VOIDmode)
3494 const_to_mem = 1;
3495 if (this_alternative[i] != (int) NO_REGS)
3496 losers++;
3499 /* Alternative loses if it requires a type of reload not
3500 permitted for this insn. We can always reload SCRATCH
3501 and objects with a REG_UNUSED note. */
3502 if (GET_CODE (operand) != SCRATCH
3503 && modified[i] != RELOAD_READ && no_output_reloads
3504 && ! find_reg_note (insn, REG_UNUSED, operand))
3505 bad = 1;
3506 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3507 && ! const_to_mem)
3508 bad = 1;
3510 /* If we can't reload this value at all, reject this
3511 alternative. Note that we could also lose due to
3512 LIMIT_RELOAD_CLASS, but we don't check that
3513 here. */
3515 if (! CONSTANT_P (operand)
3516 && (enum reg_class) this_alternative[i] != NO_REGS)
3518 if (PREFERRED_RELOAD_CLASS
3519 (operand, (enum reg_class) this_alternative[i])
3520 == NO_REGS)
3521 reject = 600;
3523 #ifdef PREFERRED_OUTPUT_RELOAD_CLASS
3524 if (operand_type[i] == RELOAD_FOR_OUTPUT
3525 && PREFERRED_OUTPUT_RELOAD_CLASS
3526 (operand, (enum reg_class) this_alternative[i])
3527 == NO_REGS)
3528 reject = 600;
3529 #endif
3532 /* We prefer to reload pseudos over reloading other things,
3533 since such reloads may be able to be eliminated later.
3534 If we are reloading a SCRATCH, we won't be generating any
3535 insns, just using a register, so it is also preferred.
3536 So bump REJECT in other cases. Don't do this in the
3537 case where we are forcing a constant into memory and
3538 it will then win since we don't want to have a different
3539 alternative match then. */
3540 if (! (REG_P (operand)
3541 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3542 && GET_CODE (operand) != SCRATCH
3543 && ! (const_to_mem && constmemok))
3544 reject += 2;
3546 /* Input reloads can be inherited more often than output
3547 reloads can be removed, so penalize output reloads. */
3548 if (operand_type[i] != RELOAD_FOR_INPUT
3549 && GET_CODE (operand) != SCRATCH)
3550 reject++;
3553 /* If this operand is a pseudo register that didn't get a hard
3554 reg and this alternative accepts some register, see if the
3555 class that we want is a subset of the preferred class for this
3556 register. If not, but it intersects that class, use the
3557 preferred class instead. If it does not intersect the preferred
3558 class, show that usage of this alternative should be discouraged;
3559 it will be discouraged more still if the register is `preferred
3560 or nothing'. We do this because it increases the chance of
3561 reusing our spill register in a later insn and avoiding a pair
3562 of memory stores and loads.
3564 Don't bother with this if this alternative will accept this
3565 operand.
3567 Don't do this for a multiword operand, since it is only a
3568 small win and has the risk of requiring more spill registers,
3569 which could cause a large loss.
3571 Don't do this if the preferred class has only one register
3572 because we might otherwise exhaust the class. */
3574 if (! win && ! did_match
3575 && this_alternative[i] != (int) NO_REGS
3576 && GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3577 && reg_class_size [(int) preferred_class[i]] > 0
3578 && ! SMALL_REGISTER_CLASS_P (preferred_class[i]))
3580 if (! reg_class_subset_p (this_alternative[i],
3581 preferred_class[i]))
3583 /* Since we don't have a way of forming the intersection,
3584 we just do something special if the preferred class
3585 is a subset of the class we have; that's the most
3586 common case anyway. */
3587 if (reg_class_subset_p (preferred_class[i],
3588 this_alternative[i]))
3589 this_alternative[i] = (int) preferred_class[i];
3590 else
3591 reject += (2 + 2 * pref_or_nothing[i]);
3596 /* Now see if any output operands that are marked "earlyclobber"
3597 in this alternative conflict with any input operands
3598 or any memory addresses. */
3600 for (i = 0; i < noperands; i++)
3601 if (this_alternative_earlyclobber[i]
3602 && (this_alternative_win[i] || this_alternative_match_win[i]))
3604 struct decomposition early_data;
3606 early_data = decompose (recog_data.operand[i]);
3608 gcc_assert (modified[i] != RELOAD_READ);
3610 if (this_alternative[i] == NO_REGS)
3612 this_alternative_earlyclobber[i] = 0;
3613 gcc_assert (this_insn_is_asm);
3614 error_for_asm (this_insn,
3615 "%<&%> constraint used with no register class");
3618 for (j = 0; j < noperands; j++)
3619 /* Is this an input operand or a memory ref? */
3620 if ((MEM_P (recog_data.operand[j])
3621 || modified[j] != RELOAD_WRITE)
3622 && j != i
3623 /* Ignore things like match_operator operands. */
3624 && *recog_data.constraints[j] != 0
3625 /* Don't count an input operand that is constrained to match
3626 the early clobber operand. */
3627 && ! (this_alternative_matches[j] == i
3628 && rtx_equal_p (recog_data.operand[i],
3629 recog_data.operand[j]))
3630 /* Is it altered by storing the earlyclobber operand? */
3631 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3632 early_data))
3634 /* If the output is in a non-empty few-regs class,
3635 it's costly to reload it, so reload the input instead. */
3636 if (SMALL_REGISTER_CLASS_P (this_alternative[i])
3637 && (REG_P (recog_data.operand[j])
3638 || GET_CODE (recog_data.operand[j]) == SUBREG))
3640 losers++;
3641 this_alternative_win[j] = 0;
3642 this_alternative_match_win[j] = 0;
3644 else
3645 break;
3647 /* If an earlyclobber operand conflicts with something,
3648 it must be reloaded, so request this and count the cost. */
3649 if (j != noperands)
3651 losers++;
3652 this_alternative_win[i] = 0;
3653 this_alternative_match_win[j] = 0;
3654 for (j = 0; j < noperands; j++)
3655 if (this_alternative_matches[j] == i
3656 && this_alternative_match_win[j])
3658 this_alternative_win[j] = 0;
3659 this_alternative_match_win[j] = 0;
3660 losers++;
3665 /* If one alternative accepts all the operands, no reload required,
3666 choose that alternative; don't consider the remaining ones. */
3667 if (losers == 0)
3669 /* Unswap these so that they are never swapped at `finish'. */
3670 if (commutative >= 0)
3672 recog_data.operand[commutative] = substed_operand[commutative];
3673 recog_data.operand[commutative + 1]
3674 = substed_operand[commutative + 1];
3676 for (i = 0; i < noperands; i++)
3678 goal_alternative_win[i] = this_alternative_win[i];
3679 goal_alternative_match_win[i] = this_alternative_match_win[i];
3680 goal_alternative[i] = this_alternative[i];
3681 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3682 goal_alternative_matches[i] = this_alternative_matches[i];
3683 goal_alternative_earlyclobber[i]
3684 = this_alternative_earlyclobber[i];
3686 goal_alternative_number = this_alternative_number;
3687 goal_alternative_swapped = swapped;
3688 goal_earlyclobber = this_earlyclobber;
3689 goto finish;
3692 /* REJECT, set by the ! and ? constraint characters and when a register
3693 would be reloaded into a non-preferred class, discourages the use of
3694 this alternative for a reload goal. REJECT is incremented by six
3695 for each ? and two for each non-preferred class. */
3696 losers = losers * 6 + reject;
3698 /* If this alternative can be made to work by reloading,
3699 and it needs less reloading than the others checked so far,
3700 record it as the chosen goal for reloading. */
3701 if (! bad && best > losers)
3703 for (i = 0; i < noperands; i++)
3705 goal_alternative[i] = this_alternative[i];
3706 goal_alternative_win[i] = this_alternative_win[i];
3707 goal_alternative_match_win[i] = this_alternative_match_win[i];
3708 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3709 goal_alternative_matches[i] = this_alternative_matches[i];
3710 goal_alternative_earlyclobber[i]
3711 = this_alternative_earlyclobber[i];
3713 goal_alternative_swapped = swapped;
3714 best = losers;
3715 goal_alternative_number = this_alternative_number;
3716 goal_earlyclobber = this_earlyclobber;
3720 /* If insn is commutative (it's safe to exchange a certain pair of operands)
3721 then we need to try each alternative twice,
3722 the second time matching those two operands
3723 as if we had exchanged them.
3724 To do this, really exchange them in operands.
3726 If we have just tried the alternatives the second time,
3727 return operands to normal and drop through. */
3729 if (commutative >= 0)
3731 swapped = !swapped;
3732 if (swapped)
3734 enum reg_class tclass;
3735 int t;
3737 recog_data.operand[commutative] = substed_operand[commutative + 1];
3738 recog_data.operand[commutative + 1] = substed_operand[commutative];
3739 /* Swap the duplicates too. */
3740 for (i = 0; i < recog_data.n_dups; i++)
3741 if (recog_data.dup_num[i] == commutative
3742 || recog_data.dup_num[i] == commutative + 1)
3743 *recog_data.dup_loc[i]
3744 = recog_data.operand[(int) recog_data.dup_num[i]];
3746 tclass = preferred_class[commutative];
3747 preferred_class[commutative] = preferred_class[commutative + 1];
3748 preferred_class[commutative + 1] = tclass;
3750 t = pref_or_nothing[commutative];
3751 pref_or_nothing[commutative] = pref_or_nothing[commutative + 1];
3752 pref_or_nothing[commutative + 1] = t;
3754 t = address_reloaded[commutative];
3755 address_reloaded[commutative] = address_reloaded[commutative + 1];
3756 address_reloaded[commutative + 1] = t;
3758 memcpy (constraints, recog_data.constraints,
3759 noperands * sizeof (const char *));
3760 goto try_swapped;
3762 else
3764 recog_data.operand[commutative] = substed_operand[commutative];
3765 recog_data.operand[commutative + 1]
3766 = substed_operand[commutative + 1];
3767 /* Unswap the duplicates too. */
3768 for (i = 0; i < recog_data.n_dups; i++)
3769 if (recog_data.dup_num[i] == commutative
3770 || recog_data.dup_num[i] == commutative + 1)
3771 *recog_data.dup_loc[i]
3772 = recog_data.operand[(int) recog_data.dup_num[i]];
3776 /* The operands don't meet the constraints.
3777 goal_alternative describes the alternative
3778 that we could reach by reloading the fewest operands.
3779 Reload so as to fit it. */
3781 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3783 /* No alternative works with reloads?? */
3784 if (insn_code_number >= 0)
3785 fatal_insn ("unable to generate reloads for:", insn);
3786 error_for_asm (insn, "inconsistent operand constraints in an %<asm%>");
3787 /* Avoid further trouble with this insn. */
3788 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3789 n_reloads = 0;
3790 return 0;
3793 /* Jump to `finish' from above if all operands are valid already.
3794 In that case, goal_alternative_win is all 1. */
3795 finish:
3797 /* Right now, for any pair of operands I and J that are required to match,
3798 with I < J,
3799 goal_alternative_matches[J] is I.
3800 Set up goal_alternative_matched as the inverse function:
3801 goal_alternative_matched[I] = J. */
3803 for (i = 0; i < noperands; i++)
3804 goal_alternative_matched[i] = -1;
3806 for (i = 0; i < noperands; i++)
3807 if (! goal_alternative_win[i]
3808 && goal_alternative_matches[i] >= 0)
3809 goal_alternative_matched[goal_alternative_matches[i]] = i;
3811 for (i = 0; i < noperands; i++)
3812 goal_alternative_win[i] |= goal_alternative_match_win[i];
3814 /* If the best alternative is with operands 1 and 2 swapped,
3815 consider them swapped before reporting the reloads. Update the
3816 operand numbers of any reloads already pushed. */
3818 if (goal_alternative_swapped)
3820 rtx tem;
3822 tem = substed_operand[commutative];
3823 substed_operand[commutative] = substed_operand[commutative + 1];
3824 substed_operand[commutative + 1] = tem;
3825 tem = recog_data.operand[commutative];
3826 recog_data.operand[commutative] = recog_data.operand[commutative + 1];
3827 recog_data.operand[commutative + 1] = tem;
3828 tem = *recog_data.operand_loc[commutative];
3829 *recog_data.operand_loc[commutative]
3830 = *recog_data.operand_loc[commutative + 1];
3831 *recog_data.operand_loc[commutative + 1] = tem;
3833 for (i = 0; i < n_reloads; i++)
3835 if (rld[i].opnum == commutative)
3836 rld[i].opnum = commutative + 1;
3837 else if (rld[i].opnum == commutative + 1)
3838 rld[i].opnum = commutative;
3842 for (i = 0; i < noperands; i++)
3844 operand_reloadnum[i] = -1;
3846 /* If this is an earlyclobber operand, we need to widen the scope.
3847 The reload must remain valid from the start of the insn being
3848 reloaded until after the operand is stored into its destination.
3849 We approximate this with RELOAD_OTHER even though we know that we
3850 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3852 One special case that is worth checking is when we have an
3853 output that is earlyclobber but isn't used past the insn (typically
3854 a SCRATCH). In this case, we only need have the reload live
3855 through the insn itself, but not for any of our input or output
3856 reloads.
3857 But we must not accidentally narrow the scope of an existing
3858 RELOAD_OTHER reload - leave these alone.
3860 In any case, anything needed to address this operand can remain
3861 however they were previously categorized. */
3863 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3864 operand_type[i]
3865 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3866 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3869 /* Any constants that aren't allowed and can't be reloaded
3870 into registers are here changed into memory references. */
3871 for (i = 0; i < noperands; i++)
3872 if (! goal_alternative_win[i])
3874 rtx op = recog_data.operand[i];
3875 rtx subreg = NULL_RTX;
3876 rtx plus = NULL_RTX;
3877 enum machine_mode mode = operand_mode[i];
3879 /* Reloads of SUBREGs of CONSTANT RTXs are handled later in
3880 push_reload so we have to let them pass here. */
3881 if (GET_CODE (op) == SUBREG)
3883 subreg = op;
3884 op = SUBREG_REG (op);
3885 mode = GET_MODE (op);
3888 if (GET_CODE (op) == PLUS)
3890 plus = op;
3891 op = XEXP (op, 1);
3894 if (CONST_POOL_OK_P (op)
3895 && ((PREFERRED_RELOAD_CLASS (op,
3896 (enum reg_class) goal_alternative[i])
3897 == NO_REGS)
3898 || no_input_reloads)
3899 && mode != VOIDmode)
3901 int this_address_reloaded;
3902 rtx tem = force_const_mem (mode, op);
3904 /* If we stripped a SUBREG or a PLUS above add it back. */
3905 if (plus != NULL_RTX)
3906 tem = gen_rtx_PLUS (mode, XEXP (plus, 0), tem);
3908 if (subreg != NULL_RTX)
3909 tem = gen_rtx_SUBREG (operand_mode[i], tem, SUBREG_BYTE (subreg));
3911 this_address_reloaded = 0;
3912 substed_operand[i] = recog_data.operand[i]
3913 = find_reloads_toplev (tem, i, address_type[i], ind_levels,
3914 0, insn, &this_address_reloaded);
3916 /* If the alternative accepts constant pool refs directly
3917 there will be no reload needed at all. */
3918 if (plus == NULL_RTX
3919 && subreg == NULL_RTX
3920 && alternative_allows_const_pool_ref (this_address_reloaded == 0
3921 ? substed_operand[i]
3922 : NULL,
3923 recog_data.constraints[i],
3924 goal_alternative_number))
3925 goal_alternative_win[i] = 1;
3929 /* Record the values of the earlyclobber operands for the caller. */
3930 if (goal_earlyclobber)
3931 for (i = 0; i < noperands; i++)
3932 if (goal_alternative_earlyclobber[i])
3933 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3935 /* Now record reloads for all the operands that need them. */
3936 for (i = 0; i < noperands; i++)
3937 if (! goal_alternative_win[i])
3939 /* Operands that match previous ones have already been handled. */
3940 if (goal_alternative_matches[i] >= 0)
3942 /* Handle an operand with a nonoffsettable address
3943 appearing where an offsettable address will do
3944 by reloading the address into a base register.
3946 ??? We can also do this when the operand is a register and
3947 reg_equiv_mem is not offsettable, but this is a bit tricky,
3948 so we don't bother with it. It may not be worth doing. */
3949 else if (goal_alternative_matched[i] == -1
3950 && goal_alternative_offmemok[i]
3951 && MEM_P (recog_data.operand[i]))
3953 /* If the address to be reloaded is a VOIDmode constant,
3954 use Pmode as mode of the reload register, as would have
3955 been done by find_reloads_address. */
3956 enum machine_mode address_mode;
3957 address_mode = GET_MODE (XEXP (recog_data.operand[i], 0));
3958 if (address_mode == VOIDmode)
3959 address_mode = Pmode;
3961 operand_reloadnum[i]
3962 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
3963 &XEXP (recog_data.operand[i], 0), (rtx*) 0,
3964 base_reg_class (VOIDmode, MEM, SCRATCH),
3965 address_mode,
3966 VOIDmode, 0, 0, i, RELOAD_FOR_INPUT);
3967 rld[operand_reloadnum[i]].inc
3968 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
3970 /* If this operand is an output, we will have made any
3971 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
3972 now we are treating part of the operand as an input, so
3973 we must change these to RELOAD_FOR_INPUT_ADDRESS. */
3975 if (modified[i] == RELOAD_WRITE)
3977 for (j = 0; j < n_reloads; j++)
3979 if (rld[j].opnum == i)
3981 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
3982 rld[j].when_needed = RELOAD_FOR_INPUT_ADDRESS;
3983 else if (rld[j].when_needed
3984 == RELOAD_FOR_OUTADDR_ADDRESS)
3985 rld[j].when_needed = RELOAD_FOR_INPADDR_ADDRESS;
3990 else if (goal_alternative_matched[i] == -1)
3992 operand_reloadnum[i]
3993 = push_reload ((modified[i] != RELOAD_WRITE
3994 ? recog_data.operand[i] : 0),
3995 (modified[i] != RELOAD_READ
3996 ? recog_data.operand[i] : 0),
3997 (modified[i] != RELOAD_WRITE
3998 ? recog_data.operand_loc[i] : 0),
3999 (modified[i] != RELOAD_READ
4000 ? recog_data.operand_loc[i] : 0),
4001 (enum reg_class) goal_alternative[i],
4002 (modified[i] == RELOAD_WRITE
4003 ? VOIDmode : operand_mode[i]),
4004 (modified[i] == RELOAD_READ
4005 ? VOIDmode : operand_mode[i]),
4006 (insn_code_number < 0 ? 0
4007 : insn_data[insn_code_number].operand[i].strict_low),
4008 0, i, operand_type[i]);
4010 /* In a matching pair of operands, one must be input only
4011 and the other must be output only.
4012 Pass the input operand as IN and the other as OUT. */
4013 else if (modified[i] == RELOAD_READ
4014 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
4016 operand_reloadnum[i]
4017 = push_reload (recog_data.operand[i],
4018 recog_data.operand[goal_alternative_matched[i]],
4019 recog_data.operand_loc[i],
4020 recog_data.operand_loc[goal_alternative_matched[i]],
4021 (enum reg_class) goal_alternative[i],
4022 operand_mode[i],
4023 operand_mode[goal_alternative_matched[i]],
4024 0, 0, i, RELOAD_OTHER);
4025 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
4027 else if (modified[i] == RELOAD_WRITE
4028 && modified[goal_alternative_matched[i]] == RELOAD_READ)
4030 operand_reloadnum[goal_alternative_matched[i]]
4031 = push_reload (recog_data.operand[goal_alternative_matched[i]],
4032 recog_data.operand[i],
4033 recog_data.operand_loc[goal_alternative_matched[i]],
4034 recog_data.operand_loc[i],
4035 (enum reg_class) goal_alternative[i],
4036 operand_mode[goal_alternative_matched[i]],
4037 operand_mode[i],
4038 0, 0, i, RELOAD_OTHER);
4039 operand_reloadnum[i] = output_reloadnum;
4041 else
4043 gcc_assert (insn_code_number < 0);
4044 error_for_asm (insn, "inconsistent operand constraints "
4045 "in an %<asm%>");
4046 /* Avoid further trouble with this insn. */
4047 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
4048 n_reloads = 0;
4049 return 0;
4052 else if (goal_alternative_matched[i] < 0
4053 && goal_alternative_matches[i] < 0
4054 && address_operand_reloaded[i] != 1
4055 && optimize)
4057 /* For each non-matching operand that's a MEM or a pseudo-register
4058 that didn't get a hard register, make an optional reload.
4059 This may get done even if the insn needs no reloads otherwise. */
4061 rtx operand = recog_data.operand[i];
4063 while (GET_CODE (operand) == SUBREG)
4064 operand = SUBREG_REG (operand);
4065 if ((MEM_P (operand)
4066 || (REG_P (operand)
4067 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4068 /* If this is only for an output, the optional reload would not
4069 actually cause us to use a register now, just note that
4070 something is stored here. */
4071 && ((enum reg_class) goal_alternative[i] != NO_REGS
4072 || modified[i] == RELOAD_WRITE)
4073 && ! no_input_reloads
4074 /* An optional output reload might allow to delete INSN later.
4075 We mustn't make in-out reloads on insns that are not permitted
4076 output reloads.
4077 If this is an asm, we can't delete it; we must not even call
4078 push_reload for an optional output reload in this case,
4079 because we can't be sure that the constraint allows a register,
4080 and push_reload verifies the constraints for asms. */
4081 && (modified[i] == RELOAD_READ
4082 || (! no_output_reloads && ! this_insn_is_asm)))
4083 operand_reloadnum[i]
4084 = push_reload ((modified[i] != RELOAD_WRITE
4085 ? recog_data.operand[i] : 0),
4086 (modified[i] != RELOAD_READ
4087 ? recog_data.operand[i] : 0),
4088 (modified[i] != RELOAD_WRITE
4089 ? recog_data.operand_loc[i] : 0),
4090 (modified[i] != RELOAD_READ
4091 ? recog_data.operand_loc[i] : 0),
4092 (enum reg_class) goal_alternative[i],
4093 (modified[i] == RELOAD_WRITE
4094 ? VOIDmode : operand_mode[i]),
4095 (modified[i] == RELOAD_READ
4096 ? VOIDmode : operand_mode[i]),
4097 (insn_code_number < 0 ? 0
4098 : insn_data[insn_code_number].operand[i].strict_low),
4099 1, i, operand_type[i]);
4100 /* If a memory reference remains (either as a MEM or a pseudo that
4101 did not get a hard register), yet we can't make an optional
4102 reload, check if this is actually a pseudo register reference;
4103 we then need to emit a USE and/or a CLOBBER so that reload
4104 inheritance will do the right thing. */
4105 else if (replace
4106 && (MEM_P (operand)
4107 || (REG_P (operand)
4108 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
4109 && reg_renumber [REGNO (operand)] < 0)))
4111 operand = *recog_data.operand_loc[i];
4113 while (GET_CODE (operand) == SUBREG)
4114 operand = SUBREG_REG (operand);
4115 if (REG_P (operand))
4117 if (modified[i] != RELOAD_WRITE)
4118 /* We mark the USE with QImode so that we recognize
4119 it as one that can be safely deleted at the end
4120 of reload. */
4121 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, operand),
4122 insn), QImode);
4123 if (modified[i] != RELOAD_READ)
4124 emit_insn_after (gen_clobber (operand), insn);
4128 else if (goal_alternative_matches[i] >= 0
4129 && goal_alternative_win[goal_alternative_matches[i]]
4130 && modified[i] == RELOAD_READ
4131 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
4132 && ! no_input_reloads && ! no_output_reloads
4133 && optimize)
4135 /* Similarly, make an optional reload for a pair of matching
4136 objects that are in MEM or a pseudo that didn't get a hard reg. */
4138 rtx operand = recog_data.operand[i];
4140 while (GET_CODE (operand) == SUBREG)
4141 operand = SUBREG_REG (operand);
4142 if ((MEM_P (operand)
4143 || (REG_P (operand)
4144 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4145 && ((enum reg_class) goal_alternative[goal_alternative_matches[i]]
4146 != NO_REGS))
4147 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
4148 = push_reload (recog_data.operand[goal_alternative_matches[i]],
4149 recog_data.operand[i],
4150 recog_data.operand_loc[goal_alternative_matches[i]],
4151 recog_data.operand_loc[i],
4152 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
4153 operand_mode[goal_alternative_matches[i]],
4154 operand_mode[i],
4155 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
4158 /* Perform whatever substitutions on the operands we are supposed
4159 to make due to commutativity or replacement of registers
4160 with equivalent constants or memory slots. */
4162 for (i = 0; i < noperands; i++)
4164 /* We only do this on the last pass through reload, because it is
4165 possible for some data (like reg_equiv_address) to be changed during
4166 later passes. Moreover, we lose the opportunity to get a useful
4167 reload_{in,out}_reg when we do these replacements. */
4169 if (replace)
4171 rtx substitution = substed_operand[i];
4173 *recog_data.operand_loc[i] = substitution;
4175 /* If we're replacing an operand with a LABEL_REF, we need to
4176 make sure that there's a REG_LABEL_OPERAND note attached to
4177 this instruction. */
4178 if (GET_CODE (substitution) == LABEL_REF
4179 && !find_reg_note (insn, REG_LABEL_OPERAND,
4180 XEXP (substitution, 0))
4181 /* For a JUMP_P, if it was a branch target it must have
4182 already been recorded as such. */
4183 && (!JUMP_P (insn)
4184 || !label_is_jump_target_p (XEXP (substitution, 0),
4185 insn)))
4186 add_reg_note (insn, REG_LABEL_OPERAND, XEXP (substitution, 0));
4188 else
4189 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
4192 /* If this insn pattern contains any MATCH_DUP's, make sure that
4193 they will be substituted if the operands they match are substituted.
4194 Also do now any substitutions we already did on the operands.
4196 Don't do this if we aren't making replacements because we might be
4197 propagating things allocated by frame pointer elimination into places
4198 it doesn't expect. */
4200 if (insn_code_number >= 0 && replace)
4201 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
4203 int opno = recog_data.dup_num[i];
4204 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
4205 dup_replacements (recog_data.dup_loc[i], recog_data.operand_loc[opno]);
4208 #if 0
4209 /* This loses because reloading of prior insns can invalidate the equivalence
4210 (or at least find_equiv_reg isn't smart enough to find it any more),
4211 causing this insn to need more reload regs than it needed before.
4212 It may be too late to make the reload regs available.
4213 Now this optimization is done safely in choose_reload_regs. */
4215 /* For each reload of a reg into some other class of reg,
4216 search for an existing equivalent reg (same value now) in the right class.
4217 We can use it as long as we don't need to change its contents. */
4218 for (i = 0; i < n_reloads; i++)
4219 if (rld[i].reg_rtx == 0
4220 && rld[i].in != 0
4221 && REG_P (rld[i].in)
4222 && rld[i].out == 0)
4224 rld[i].reg_rtx
4225 = find_equiv_reg (rld[i].in, insn, rld[i].rclass, -1,
4226 static_reload_reg_p, 0, rld[i].inmode);
4227 /* Prevent generation of insn to load the value
4228 because the one we found already has the value. */
4229 if (rld[i].reg_rtx)
4230 rld[i].in = rld[i].reg_rtx;
4232 #endif
4234 /* If we detected error and replaced asm instruction by USE, forget about the
4235 reloads. */
4236 if (GET_CODE (PATTERN (insn)) == USE
4237 && GET_CODE (XEXP (PATTERN (insn), 0)) == CONST_INT)
4238 n_reloads = 0;
4240 /* Perhaps an output reload can be combined with another
4241 to reduce needs by one. */
4242 if (!goal_earlyclobber)
4243 combine_reloads ();
4245 /* If we have a pair of reloads for parts of an address, they are reloading
4246 the same object, the operands themselves were not reloaded, and they
4247 are for two operands that are supposed to match, merge the reloads and
4248 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
4250 for (i = 0; i < n_reloads; i++)
4252 int k;
4254 for (j = i + 1; j < n_reloads; j++)
4255 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4256 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4257 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4258 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4259 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
4260 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4261 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4262 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4263 && rtx_equal_p (rld[i].in, rld[j].in)
4264 && (operand_reloadnum[rld[i].opnum] < 0
4265 || rld[operand_reloadnum[rld[i].opnum]].optional)
4266 && (operand_reloadnum[rld[j].opnum] < 0
4267 || rld[operand_reloadnum[rld[j].opnum]].optional)
4268 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
4269 || (goal_alternative_matches[rld[j].opnum]
4270 == rld[i].opnum)))
4272 for (k = 0; k < n_replacements; k++)
4273 if (replacements[k].what == j)
4274 replacements[k].what = i;
4276 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4277 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4278 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4279 else
4280 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4281 rld[j].in = 0;
4285 /* Scan all the reloads and update their type.
4286 If a reload is for the address of an operand and we didn't reload
4287 that operand, change the type. Similarly, change the operand number
4288 of a reload when two operands match. If a reload is optional, treat it
4289 as though the operand isn't reloaded.
4291 ??? This latter case is somewhat odd because if we do the optional
4292 reload, it means the object is hanging around. Thus we need only
4293 do the address reload if the optional reload was NOT done.
4295 Change secondary reloads to be the address type of their operand, not
4296 the normal type.
4298 If an operand's reload is now RELOAD_OTHER, change any
4299 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
4300 RELOAD_FOR_OTHER_ADDRESS. */
4302 for (i = 0; i < n_reloads; i++)
4304 if (rld[i].secondary_p
4305 && rld[i].when_needed == operand_type[rld[i].opnum])
4306 rld[i].when_needed = address_type[rld[i].opnum];
4308 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4309 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4310 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4311 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4312 && (operand_reloadnum[rld[i].opnum] < 0
4313 || rld[operand_reloadnum[rld[i].opnum]].optional))
4315 /* If we have a secondary reload to go along with this reload,
4316 change its type to RELOAD_FOR_OPADDR_ADDR. */
4318 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4319 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4320 && rld[i].secondary_in_reload != -1)
4322 int secondary_in_reload = rld[i].secondary_in_reload;
4324 rld[secondary_in_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4326 /* If there's a tertiary reload we have to change it also. */
4327 if (secondary_in_reload > 0
4328 && rld[secondary_in_reload].secondary_in_reload != -1)
4329 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
4330 = RELOAD_FOR_OPADDR_ADDR;
4333 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4334 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4335 && rld[i].secondary_out_reload != -1)
4337 int secondary_out_reload = rld[i].secondary_out_reload;
4339 rld[secondary_out_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4341 /* If there's a tertiary reload we have to change it also. */
4342 if (secondary_out_reload
4343 && rld[secondary_out_reload].secondary_out_reload != -1)
4344 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
4345 = RELOAD_FOR_OPADDR_ADDR;
4348 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4349 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4350 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4351 else
4352 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4355 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4356 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4357 && operand_reloadnum[rld[i].opnum] >= 0
4358 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
4359 == RELOAD_OTHER))
4360 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4362 if (goal_alternative_matches[rld[i].opnum] >= 0)
4363 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
4366 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
4367 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
4368 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
4370 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
4371 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
4372 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
4373 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
4374 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
4375 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
4376 This is complicated by the fact that a single operand can have more
4377 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
4378 choose_reload_regs without affecting code quality, and cases that
4379 actually fail are extremely rare, so it turns out to be better to fix
4380 the problem here by not generating cases that choose_reload_regs will
4381 fail for. */
4382 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
4383 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
4384 a single operand.
4385 We can reduce the register pressure by exploiting that a
4386 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4387 does not conflict with any of them, if it is only used for the first of
4388 the RELOAD_FOR_X_ADDRESS reloads. */
4390 int first_op_addr_num = -2;
4391 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4392 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4393 int need_change = 0;
4394 /* We use last_op_addr_reload and the contents of the above arrays
4395 first as flags - -2 means no instance encountered, -1 means exactly
4396 one instance encountered.
4397 If more than one instance has been encountered, we store the reload
4398 number of the first reload of the kind in question; reload numbers
4399 are known to be non-negative. */
4400 for (i = 0; i < noperands; i++)
4401 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4402 for (i = n_reloads - 1; i >= 0; i--)
4404 switch (rld[i].when_needed)
4406 case RELOAD_FOR_OPERAND_ADDRESS:
4407 if (++first_op_addr_num >= 0)
4409 first_op_addr_num = i;
4410 need_change = 1;
4412 break;
4413 case RELOAD_FOR_INPUT_ADDRESS:
4414 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4416 first_inpaddr_num[rld[i].opnum] = i;
4417 need_change = 1;
4419 break;
4420 case RELOAD_FOR_OUTPUT_ADDRESS:
4421 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4423 first_outpaddr_num[rld[i].opnum] = i;
4424 need_change = 1;
4426 break;
4427 default:
4428 break;
4432 if (need_change)
4434 for (i = 0; i < n_reloads; i++)
4436 int first_num;
4437 enum reload_type type;
4439 switch (rld[i].when_needed)
4441 case RELOAD_FOR_OPADDR_ADDR:
4442 first_num = first_op_addr_num;
4443 type = RELOAD_FOR_OPERAND_ADDRESS;
4444 break;
4445 case RELOAD_FOR_INPADDR_ADDRESS:
4446 first_num = first_inpaddr_num[rld[i].opnum];
4447 type = RELOAD_FOR_INPUT_ADDRESS;
4448 break;
4449 case RELOAD_FOR_OUTADDR_ADDRESS:
4450 first_num = first_outpaddr_num[rld[i].opnum];
4451 type = RELOAD_FOR_OUTPUT_ADDRESS;
4452 break;
4453 default:
4454 continue;
4456 if (first_num < 0)
4457 continue;
4458 else if (i > first_num)
4459 rld[i].when_needed = type;
4460 else
4462 /* Check if the only TYPE reload that uses reload I is
4463 reload FIRST_NUM. */
4464 for (j = n_reloads - 1; j > first_num; j--)
4466 if (rld[j].when_needed == type
4467 && (rld[i].secondary_p
4468 ? rld[j].secondary_in_reload == i
4469 : reg_mentioned_p (rld[i].in, rld[j].in)))
4471 rld[i].when_needed = type;
4472 break;
4480 /* See if we have any reloads that are now allowed to be merged
4481 because we've changed when the reload is needed to
4482 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4483 check for the most common cases. */
4485 for (i = 0; i < n_reloads; i++)
4486 if (rld[i].in != 0 && rld[i].out == 0
4487 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4488 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4489 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4490 for (j = 0; j < n_reloads; j++)
4491 if (i != j && rld[j].in != 0 && rld[j].out == 0
4492 && rld[j].when_needed == rld[i].when_needed
4493 && MATCHES (rld[i].in, rld[j].in)
4494 && rld[i].rclass == rld[j].rclass
4495 && !rld[i].nocombine && !rld[j].nocombine
4496 && rld[i].reg_rtx == rld[j].reg_rtx)
4498 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4499 transfer_replacements (i, j);
4500 rld[j].in = 0;
4503 #ifdef HAVE_cc0
4504 /* If we made any reloads for addresses, see if they violate a
4505 "no input reloads" requirement for this insn. But loads that we
4506 do after the insn (such as for output addresses) are fine. */
4507 if (no_input_reloads)
4508 for (i = 0; i < n_reloads; i++)
4509 gcc_assert (rld[i].in == 0
4510 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS
4511 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS);
4512 #endif
4514 /* Compute reload_mode and reload_nregs. */
4515 for (i = 0; i < n_reloads; i++)
4517 rld[i].mode
4518 = (rld[i].inmode == VOIDmode
4519 || (GET_MODE_SIZE (rld[i].outmode)
4520 > GET_MODE_SIZE (rld[i].inmode)))
4521 ? rld[i].outmode : rld[i].inmode;
4523 rld[i].nregs = CLASS_MAX_NREGS (rld[i].rclass, rld[i].mode);
4526 /* Special case a simple move with an input reload and a
4527 destination of a hard reg, if the hard reg is ok, use it. */
4528 for (i = 0; i < n_reloads; i++)
4529 if (rld[i].when_needed == RELOAD_FOR_INPUT
4530 && GET_CODE (PATTERN (insn)) == SET
4531 && REG_P (SET_DEST (PATTERN (insn)))
4532 && (SET_SRC (PATTERN (insn)) == rld[i].in
4533 || SET_SRC (PATTERN (insn)) == rld[i].in_reg)
4534 && !elimination_target_reg_p (SET_DEST (PATTERN (insn))))
4536 rtx dest = SET_DEST (PATTERN (insn));
4537 unsigned int regno = REGNO (dest);
4539 if (regno < FIRST_PSEUDO_REGISTER
4540 && TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno)
4541 && HARD_REGNO_MODE_OK (regno, rld[i].mode))
4543 int nr = hard_regno_nregs[regno][rld[i].mode];
4544 int ok = 1, nri;
4546 for (nri = 1; nri < nr; nri ++)
4547 if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno + nri))
4548 ok = 0;
4550 if (ok)
4551 rld[i].reg_rtx = dest;
4555 return retval;
4558 /* Return true if alternative number ALTNUM in constraint-string
4559 CONSTRAINT is guaranteed to accept a reloaded constant-pool reference.
4560 MEM gives the reference if it didn't need any reloads, otherwise it
4561 is null. */
4563 static bool
4564 alternative_allows_const_pool_ref (rtx mem, const char *constraint, int altnum)
4566 int c;
4568 /* Skip alternatives before the one requested. */
4569 while (altnum > 0)
4571 while (*constraint++ != ',');
4572 altnum--;
4574 /* Scan the requested alternative for TARGET_MEM_CONSTRAINT or 'o'.
4575 If one of them is present, this alternative accepts the result of
4576 passing a constant-pool reference through find_reloads_toplev.
4578 The same is true of extra memory constraints if the address
4579 was reloaded into a register. However, the target may elect
4580 to disallow the original constant address, forcing it to be
4581 reloaded into a register instead. */
4582 for (; (c = *constraint) && c != ',' && c != '#';
4583 constraint += CONSTRAINT_LEN (c, constraint))
4585 if (c == TARGET_MEM_CONSTRAINT || c == 'o')
4586 return true;
4587 #ifdef EXTRA_CONSTRAINT_STR
4588 if (EXTRA_MEMORY_CONSTRAINT (c, constraint)
4589 && (mem == NULL || EXTRA_CONSTRAINT_STR (mem, c, constraint)))
4590 return true;
4591 #endif
4593 return false;
4596 /* Scan X for memory references and scan the addresses for reloading.
4597 Also checks for references to "constant" regs that we want to eliminate
4598 and replaces them with the values they stand for.
4599 We may alter X destructively if it contains a reference to such.
4600 If X is just a constant reg, we return the equivalent value
4601 instead of X.
4603 IND_LEVELS says how many levels of indirect addressing this machine
4604 supports.
4606 OPNUM and TYPE identify the purpose of the reload.
4608 IS_SET_DEST is true if X is the destination of a SET, which is not
4609 appropriate to be replaced by a constant.
4611 INSN, if nonzero, is the insn in which we do the reload. It is used
4612 to determine if we may generate output reloads, and where to put USEs
4613 for pseudos that we have to replace with stack slots.
4615 ADDRESS_RELOADED. If nonzero, is a pointer to where we put the
4616 result of find_reloads_address. */
4618 static rtx
4619 find_reloads_toplev (rtx x, int opnum, enum reload_type type,
4620 int ind_levels, int is_set_dest, rtx insn,
4621 int *address_reloaded)
4623 RTX_CODE code = GET_CODE (x);
4625 const char *fmt = GET_RTX_FORMAT (code);
4626 int i;
4627 int copied;
4629 if (code == REG)
4631 /* This code is duplicated for speed in find_reloads. */
4632 int regno = REGNO (x);
4633 if (reg_equiv_constant[regno] != 0 && !is_set_dest)
4634 x = reg_equiv_constant[regno];
4635 #if 0
4636 /* This creates (subreg (mem...)) which would cause an unnecessary
4637 reload of the mem. */
4638 else if (reg_equiv_mem[regno] != 0)
4639 x = reg_equiv_mem[regno];
4640 #endif
4641 else if (reg_equiv_memory_loc[regno]
4642 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
4644 rtx mem = make_memloc (x, regno);
4645 if (reg_equiv_address[regno]
4646 || ! rtx_equal_p (mem, reg_equiv_mem[regno]))
4648 /* If this is not a toplevel operand, find_reloads doesn't see
4649 this substitution. We have to emit a USE of the pseudo so
4650 that delete_output_reload can see it. */
4651 if (replace_reloads && recog_data.operand[opnum] != x)
4652 /* We mark the USE with QImode so that we recognize it
4653 as one that can be safely deleted at the end of
4654 reload. */
4655 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, x), insn),
4656 QImode);
4657 x = mem;
4658 i = find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4659 opnum, type, ind_levels, insn);
4660 if (!rtx_equal_p (x, mem))
4661 push_reg_equiv_alt_mem (regno, x);
4662 if (address_reloaded)
4663 *address_reloaded = i;
4666 return x;
4668 if (code == MEM)
4670 rtx tem = x;
4672 i = find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4673 opnum, type, ind_levels, insn);
4674 if (address_reloaded)
4675 *address_reloaded = i;
4677 return tem;
4680 if (code == SUBREG && REG_P (SUBREG_REG (x)))
4682 /* Check for SUBREG containing a REG that's equivalent to a
4683 constant. If the constant has a known value, truncate it
4684 right now. Similarly if we are extracting a single-word of a
4685 multi-word constant. If the constant is symbolic, allow it
4686 to be substituted normally. push_reload will strip the
4687 subreg later. The constant must not be VOIDmode, because we
4688 will lose the mode of the register (this should never happen
4689 because one of the cases above should handle it). */
4691 int regno = REGNO (SUBREG_REG (x));
4692 rtx tem;
4694 if (regno >= FIRST_PSEUDO_REGISTER
4695 && reg_renumber[regno] < 0
4696 && reg_equiv_constant[regno] != 0)
4698 tem =
4699 simplify_gen_subreg (GET_MODE (x), reg_equiv_constant[regno],
4700 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
4701 gcc_assert (tem);
4702 if (CONSTANT_P (tem) && !LEGITIMATE_CONSTANT_P (tem))
4704 tem = force_const_mem (GET_MODE (x), tem);
4705 i = find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4706 &XEXP (tem, 0), opnum, type,
4707 ind_levels, insn);
4708 if (address_reloaded)
4709 *address_reloaded = i;
4711 return tem;
4714 /* If the subreg contains a reg that will be converted to a mem,
4715 convert the subreg to a narrower memref now.
4716 Otherwise, we would get (subreg (mem ...) ...),
4717 which would force reload of the mem.
4719 We also need to do this if there is an equivalent MEM that is
4720 not offsettable. In that case, alter_subreg would produce an
4721 invalid address on big-endian machines.
4723 For machines that extend byte loads, we must not reload using
4724 a wider mode if we have a paradoxical SUBREG. find_reloads will
4725 force a reload in that case. So we should not do anything here. */
4727 if (regno >= FIRST_PSEUDO_REGISTER
4728 #ifdef LOAD_EXTEND_OP
4729 && (GET_MODE_SIZE (GET_MODE (x))
4730 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
4731 #endif
4732 && (reg_equiv_address[regno] != 0
4733 || (reg_equiv_mem[regno] != 0
4734 && (! strict_memory_address_p (GET_MODE (x),
4735 XEXP (reg_equiv_mem[regno], 0))
4736 || ! offsettable_memref_p (reg_equiv_mem[regno])
4737 || num_not_at_initial_offset))))
4738 x = find_reloads_subreg_address (x, 1, opnum, type, ind_levels,
4739 insn);
4742 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4744 if (fmt[i] == 'e')
4746 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4747 ind_levels, is_set_dest, insn,
4748 address_reloaded);
4749 /* If we have replaced a reg with it's equivalent memory loc -
4750 that can still be handled here e.g. if it's in a paradoxical
4751 subreg - we must make the change in a copy, rather than using
4752 a destructive change. This way, find_reloads can still elect
4753 not to do the change. */
4754 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4756 x = shallow_copy_rtx (x);
4757 copied = 1;
4759 XEXP (x, i) = new_part;
4762 return x;
4765 /* Return a mem ref for the memory equivalent of reg REGNO.
4766 This mem ref is not shared with anything. */
4768 static rtx
4769 make_memloc (rtx ad, int regno)
4771 /* We must rerun eliminate_regs, in case the elimination
4772 offsets have changed. */
4773 rtx tem
4774 = XEXP (eliminate_regs (reg_equiv_memory_loc[regno], 0, NULL_RTX), 0);
4776 /* If TEM might contain a pseudo, we must copy it to avoid
4777 modifying it when we do the substitution for the reload. */
4778 if (rtx_varies_p (tem, 0))
4779 tem = copy_rtx (tem);
4781 tem = replace_equiv_address_nv (reg_equiv_memory_loc[regno], tem);
4782 tem = adjust_address_nv (tem, GET_MODE (ad), 0);
4784 /* Copy the result if it's still the same as the equivalence, to avoid
4785 modifying it when we do the substitution for the reload. */
4786 if (tem == reg_equiv_memory_loc[regno])
4787 tem = copy_rtx (tem);
4788 return tem;
4791 /* Returns true if AD could be turned into a valid memory reference
4792 to mode MODE by reloading the part pointed to by PART into a
4793 register. */
4795 static int
4796 maybe_memory_address_p (enum machine_mode mode, rtx ad, rtx *part)
4798 int retv;
4799 rtx tem = *part;
4800 rtx reg = gen_rtx_REG (GET_MODE (tem), max_reg_num ());
4802 *part = reg;
4803 retv = memory_address_p (mode, ad);
4804 *part = tem;
4806 return retv;
4809 /* Record all reloads needed for handling memory address AD
4810 which appears in *LOC in a memory reference to mode MODE
4811 which itself is found in location *MEMREFLOC.
4812 Note that we take shortcuts assuming that no multi-reg machine mode
4813 occurs as part of an address.
4815 OPNUM and TYPE specify the purpose of this reload.
4817 IND_LEVELS says how many levels of indirect addressing this machine
4818 supports.
4820 INSN, if nonzero, is the insn in which we do the reload. It is used
4821 to determine if we may generate output reloads, and where to put USEs
4822 for pseudos that we have to replace with stack slots.
4824 Value is one if this address is reloaded or replaced as a whole; it is
4825 zero if the top level of this address was not reloaded or replaced, and
4826 it is -1 if it may or may not have been reloaded or replaced.
4828 Note that there is no verification that the address will be valid after
4829 this routine does its work. Instead, we rely on the fact that the address
4830 was valid when reload started. So we need only undo things that reload
4831 could have broken. These are wrong register types, pseudos not allocated
4832 to a hard register, and frame pointer elimination. */
4834 static int
4835 find_reloads_address (enum machine_mode mode, rtx *memrefloc, rtx ad,
4836 rtx *loc, int opnum, enum reload_type type,
4837 int ind_levels, rtx insn)
4839 int regno;
4840 int removed_and = 0;
4841 int op_index;
4842 rtx tem;
4844 /* If the address is a register, see if it is a legitimate address and
4845 reload if not. We first handle the cases where we need not reload
4846 or where we must reload in a non-standard way. */
4848 if (REG_P (ad))
4850 regno = REGNO (ad);
4852 if (reg_equiv_constant[regno] != 0)
4854 find_reloads_address_part (reg_equiv_constant[regno], loc,
4855 base_reg_class (mode, MEM, SCRATCH),
4856 GET_MODE (ad), opnum, type, ind_levels);
4857 return 1;
4860 tem = reg_equiv_memory_loc[regno];
4861 if (tem != 0)
4863 if (reg_equiv_address[regno] != 0 || num_not_at_initial_offset)
4865 tem = make_memloc (ad, regno);
4866 if (! strict_memory_address_p (GET_MODE (tem), XEXP (tem, 0)))
4868 rtx orig = tem;
4870 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4871 &XEXP (tem, 0), opnum,
4872 ADDR_TYPE (type), ind_levels, insn);
4873 if (!rtx_equal_p (tem, orig))
4874 push_reg_equiv_alt_mem (regno, tem);
4876 /* We can avoid a reload if the register's equivalent memory
4877 expression is valid as an indirect memory address.
4878 But not all addresses are valid in a mem used as an indirect
4879 address: only reg or reg+constant. */
4881 if (ind_levels > 0
4882 && strict_memory_address_p (mode, tem)
4883 && (REG_P (XEXP (tem, 0))
4884 || (GET_CODE (XEXP (tem, 0)) == PLUS
4885 && REG_P (XEXP (XEXP (tem, 0), 0))
4886 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4888 /* TEM is not the same as what we'll be replacing the
4889 pseudo with after reload, put a USE in front of INSN
4890 in the final reload pass. */
4891 if (replace_reloads
4892 && num_not_at_initial_offset
4893 && ! rtx_equal_p (tem, reg_equiv_mem[regno]))
4895 *loc = tem;
4896 /* We mark the USE with QImode so that we
4897 recognize it as one that can be safely
4898 deleted at the end of reload. */
4899 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad),
4900 insn), QImode);
4902 /* This doesn't really count as replacing the address
4903 as a whole, since it is still a memory access. */
4905 return 0;
4907 ad = tem;
4911 /* The only remaining case where we can avoid a reload is if this is a
4912 hard register that is valid as a base register and which is not the
4913 subject of a CLOBBER in this insn. */
4915 else if (regno < FIRST_PSEUDO_REGISTER
4916 && regno_ok_for_base_p (regno, mode, MEM, SCRATCH)
4917 && ! regno_clobbered_p (regno, this_insn, mode, 0))
4918 return 0;
4920 /* If we do not have one of the cases above, we must do the reload. */
4921 push_reload (ad, NULL_RTX, loc, (rtx*) 0, base_reg_class (mode, MEM, SCRATCH),
4922 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4923 return 1;
4926 if (strict_memory_address_p (mode, ad))
4928 /* The address appears valid, so reloads are not needed.
4929 But the address may contain an eliminable register.
4930 This can happen because a machine with indirect addressing
4931 may consider a pseudo register by itself a valid address even when
4932 it has failed to get a hard reg.
4933 So do a tree-walk to find and eliminate all such regs. */
4935 /* But first quickly dispose of a common case. */
4936 if (GET_CODE (ad) == PLUS
4937 && GET_CODE (XEXP (ad, 1)) == CONST_INT
4938 && REG_P (XEXP (ad, 0))
4939 && reg_equiv_constant[REGNO (XEXP (ad, 0))] == 0)
4940 return 0;
4942 subst_reg_equivs_changed = 0;
4943 *loc = subst_reg_equivs (ad, insn);
4945 if (! subst_reg_equivs_changed)
4946 return 0;
4948 /* Check result for validity after substitution. */
4949 if (strict_memory_address_p (mode, ad))
4950 return 0;
4953 #ifdef LEGITIMIZE_RELOAD_ADDRESS
4956 if (memrefloc)
4958 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
4959 ind_levels, win);
4961 break;
4962 win:
4963 *memrefloc = copy_rtx (*memrefloc);
4964 XEXP (*memrefloc, 0) = ad;
4965 move_replacements (&ad, &XEXP (*memrefloc, 0));
4966 return -1;
4968 while (0);
4969 #endif
4971 /* The address is not valid. We have to figure out why. First see if
4972 we have an outer AND and remove it if so. Then analyze what's inside. */
4974 if (GET_CODE (ad) == AND)
4976 removed_and = 1;
4977 loc = &XEXP (ad, 0);
4978 ad = *loc;
4981 /* One possibility for why the address is invalid is that it is itself
4982 a MEM. This can happen when the frame pointer is being eliminated, a
4983 pseudo is not allocated to a hard register, and the offset between the
4984 frame and stack pointers is not its initial value. In that case the
4985 pseudo will have been replaced by a MEM referring to the
4986 stack pointer. */
4987 if (MEM_P (ad))
4989 /* First ensure that the address in this MEM is valid. Then, unless
4990 indirect addresses are valid, reload the MEM into a register. */
4991 tem = ad;
4992 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
4993 opnum, ADDR_TYPE (type),
4994 ind_levels == 0 ? 0 : ind_levels - 1, insn);
4996 /* If tem was changed, then we must create a new memory reference to
4997 hold it and store it back into memrefloc. */
4998 if (tem != ad && memrefloc)
5000 *memrefloc = copy_rtx (*memrefloc);
5001 copy_replacements (tem, XEXP (*memrefloc, 0));
5002 loc = &XEXP (*memrefloc, 0);
5003 if (removed_and)
5004 loc = &XEXP (*loc, 0);
5007 /* Check similar cases as for indirect addresses as above except
5008 that we can allow pseudos and a MEM since they should have been
5009 taken care of above. */
5011 if (ind_levels == 0
5012 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
5013 || MEM_P (XEXP (tem, 0))
5014 || ! (REG_P (XEXP (tem, 0))
5015 || (GET_CODE (XEXP (tem, 0)) == PLUS
5016 && REG_P (XEXP (XEXP (tem, 0), 0))
5017 && GET_CODE (XEXP (XEXP (tem, 0), 1)) == CONST_INT)))
5019 /* Must use TEM here, not AD, since it is the one that will
5020 have any subexpressions reloaded, if needed. */
5021 push_reload (tem, NULL_RTX, loc, (rtx*) 0,
5022 base_reg_class (mode, MEM, SCRATCH), GET_MODE (tem),
5023 VOIDmode, 0,
5024 0, opnum, type);
5025 return ! removed_and;
5027 else
5028 return 0;
5031 /* If we have address of a stack slot but it's not valid because the
5032 displacement is too large, compute the sum in a register.
5033 Handle all base registers here, not just fp/ap/sp, because on some
5034 targets (namely SH) we can also get too large displacements from
5035 big-endian corrections. */
5036 else if (GET_CODE (ad) == PLUS
5037 && REG_P (XEXP (ad, 0))
5038 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
5039 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5040 && regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, PLUS,
5041 CONST_INT))
5044 /* Unshare the MEM rtx so we can safely alter it. */
5045 if (memrefloc)
5047 *memrefloc = copy_rtx (*memrefloc);
5048 loc = &XEXP (*memrefloc, 0);
5049 if (removed_and)
5050 loc = &XEXP (*loc, 0);
5053 if (double_reg_address_ok)
5055 /* Unshare the sum as well. */
5056 *loc = ad = copy_rtx (ad);
5058 /* Reload the displacement into an index reg.
5059 We assume the frame pointer or arg pointer is a base reg. */
5060 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
5061 INDEX_REG_CLASS, GET_MODE (ad), opnum,
5062 type, ind_levels);
5063 return 0;
5065 else
5067 /* If the sum of two regs is not necessarily valid,
5068 reload the sum into a base reg.
5069 That will at least work. */
5070 find_reloads_address_part (ad, loc,
5071 base_reg_class (mode, MEM, SCRATCH),
5072 Pmode, opnum, type, ind_levels);
5074 return ! removed_and;
5077 /* If we have an indexed stack slot, there are three possible reasons why
5078 it might be invalid: The index might need to be reloaded, the address
5079 might have been made by frame pointer elimination and hence have a
5080 constant out of range, or both reasons might apply.
5082 We can easily check for an index needing reload, but even if that is the
5083 case, we might also have an invalid constant. To avoid making the
5084 conservative assumption and requiring two reloads, we see if this address
5085 is valid when not interpreted strictly. If it is, the only problem is
5086 that the index needs a reload and find_reloads_address_1 will take care
5087 of it.
5089 Handle all base registers here, not just fp/ap/sp, because on some
5090 targets (namely SPARC) we can also get invalid addresses from preventive
5091 subreg big-endian corrections made by find_reloads_toplev. We
5092 can also get expressions involving LO_SUM (rather than PLUS) from
5093 find_reloads_subreg_address.
5095 If we decide to do something, it must be that `double_reg_address_ok'
5096 is true. We generate a reload of the base register + constant and
5097 rework the sum so that the reload register will be added to the index.
5098 This is safe because we know the address isn't shared.
5100 We check for the base register as both the first and second operand of
5101 the innermost PLUS and/or LO_SUM. */
5103 for (op_index = 0; op_index < 2; ++op_index)
5105 rtx operand, addend;
5106 enum rtx_code inner_code;
5108 if (GET_CODE (ad) != PLUS)
5109 continue;
5111 inner_code = GET_CODE (XEXP (ad, 0));
5112 if (!(GET_CODE (ad) == PLUS
5113 && GET_CODE (XEXP (ad, 1)) == CONST_INT
5114 && (inner_code == PLUS || inner_code == LO_SUM)))
5115 continue;
5117 operand = XEXP (XEXP (ad, 0), op_index);
5118 if (!REG_P (operand) || REGNO (operand) >= FIRST_PSEUDO_REGISTER)
5119 continue;
5121 addend = XEXP (XEXP (ad, 0), 1 - op_index);
5123 if ((regno_ok_for_base_p (REGNO (operand), mode, inner_code,
5124 GET_CODE (addend))
5125 || operand == frame_pointer_rtx
5126 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
5127 || operand == hard_frame_pointer_rtx
5128 #endif
5129 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5130 || operand == arg_pointer_rtx
5131 #endif
5132 || operand == stack_pointer_rtx)
5133 && ! maybe_memory_address_p (mode, ad,
5134 &XEXP (XEXP (ad, 0), 1 - op_index)))
5136 rtx offset_reg;
5137 enum reg_class cls;
5139 offset_reg = plus_constant (operand, INTVAL (XEXP (ad, 1)));
5141 /* Form the adjusted address. */
5142 if (GET_CODE (XEXP (ad, 0)) == PLUS)
5143 ad = gen_rtx_PLUS (GET_MODE (ad),
5144 op_index == 0 ? offset_reg : addend,
5145 op_index == 0 ? addend : offset_reg);
5146 else
5147 ad = gen_rtx_LO_SUM (GET_MODE (ad),
5148 op_index == 0 ? offset_reg : addend,
5149 op_index == 0 ? addend : offset_reg);
5150 *loc = ad;
5152 cls = base_reg_class (mode, MEM, GET_CODE (addend));
5153 find_reloads_address_part (XEXP (ad, op_index),
5154 &XEXP (ad, op_index), cls,
5155 GET_MODE (ad), opnum, type, ind_levels);
5156 find_reloads_address_1 (mode,
5157 XEXP (ad, 1 - op_index), 1, GET_CODE (ad),
5158 GET_CODE (XEXP (ad, op_index)),
5159 &XEXP (ad, 1 - op_index), opnum,
5160 type, 0, insn);
5162 return 0;
5166 /* See if address becomes valid when an eliminable register
5167 in a sum is replaced. */
5169 tem = ad;
5170 if (GET_CODE (ad) == PLUS)
5171 tem = subst_indexed_address (ad);
5172 if (tem != ad && strict_memory_address_p (mode, tem))
5174 /* Ok, we win that way. Replace any additional eliminable
5175 registers. */
5177 subst_reg_equivs_changed = 0;
5178 tem = subst_reg_equivs (tem, insn);
5180 /* Make sure that didn't make the address invalid again. */
5182 if (! subst_reg_equivs_changed || strict_memory_address_p (mode, tem))
5184 *loc = tem;
5185 return 0;
5189 /* If constants aren't valid addresses, reload the constant address
5190 into a register. */
5191 if (CONSTANT_P (ad) && ! strict_memory_address_p (mode, ad))
5193 /* If AD is an address in the constant pool, the MEM rtx may be shared.
5194 Unshare it so we can safely alter it. */
5195 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
5196 && CONSTANT_POOL_ADDRESS_P (ad))
5198 *memrefloc = copy_rtx (*memrefloc);
5199 loc = &XEXP (*memrefloc, 0);
5200 if (removed_and)
5201 loc = &XEXP (*loc, 0);
5204 find_reloads_address_part (ad, loc, base_reg_class (mode, MEM, SCRATCH),
5205 Pmode, opnum, type, ind_levels);
5206 return ! removed_and;
5209 return find_reloads_address_1 (mode, ad, 0, MEM, SCRATCH, loc, opnum, type,
5210 ind_levels, insn);
5213 /* Find all pseudo regs appearing in AD
5214 that are eliminable in favor of equivalent values
5215 and do not have hard regs; replace them by their equivalents.
5216 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
5217 front of it for pseudos that we have to replace with stack slots. */
5219 static rtx
5220 subst_reg_equivs (rtx ad, rtx insn)
5222 RTX_CODE code = GET_CODE (ad);
5223 int i;
5224 const char *fmt;
5226 switch (code)
5228 case HIGH:
5229 case CONST_INT:
5230 case CONST:
5231 case CONST_DOUBLE:
5232 case CONST_FIXED:
5233 case CONST_VECTOR:
5234 case SYMBOL_REF:
5235 case LABEL_REF:
5236 case PC:
5237 case CC0:
5238 return ad;
5240 case REG:
5242 int regno = REGNO (ad);
5244 if (reg_equiv_constant[regno] != 0)
5246 subst_reg_equivs_changed = 1;
5247 return reg_equiv_constant[regno];
5249 if (reg_equiv_memory_loc[regno] && num_not_at_initial_offset)
5251 rtx mem = make_memloc (ad, regno);
5252 if (! rtx_equal_p (mem, reg_equiv_mem[regno]))
5254 subst_reg_equivs_changed = 1;
5255 /* We mark the USE with QImode so that we recognize it
5256 as one that can be safely deleted at the end of
5257 reload. */
5258 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn),
5259 QImode);
5260 return mem;
5264 return ad;
5266 case PLUS:
5267 /* Quickly dispose of a common case. */
5268 if (XEXP (ad, 0) == frame_pointer_rtx
5269 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
5270 return ad;
5271 break;
5273 default:
5274 break;
5277 fmt = GET_RTX_FORMAT (code);
5278 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5279 if (fmt[i] == 'e')
5280 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
5281 return ad;
5284 /* Compute the sum of X and Y, making canonicalizations assumed in an
5285 address, namely: sum constant integers, surround the sum of two
5286 constants with a CONST, put the constant as the second operand, and
5287 group the constant on the outermost sum.
5289 This routine assumes both inputs are already in canonical form. */
5292 form_sum (rtx x, rtx y)
5294 rtx tem;
5295 enum machine_mode mode = GET_MODE (x);
5297 if (mode == VOIDmode)
5298 mode = GET_MODE (y);
5300 if (mode == VOIDmode)
5301 mode = Pmode;
5303 if (GET_CODE (x) == CONST_INT)
5304 return plus_constant (y, INTVAL (x));
5305 else if (GET_CODE (y) == CONST_INT)
5306 return plus_constant (x, INTVAL (y));
5307 else if (CONSTANT_P (x))
5308 tem = x, x = y, y = tem;
5310 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
5311 return form_sum (XEXP (x, 0), form_sum (XEXP (x, 1), y));
5313 /* Note that if the operands of Y are specified in the opposite
5314 order in the recursive calls below, infinite recursion will occur. */
5315 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
5316 return form_sum (form_sum (x, XEXP (y, 0)), XEXP (y, 1));
5318 /* If both constant, encapsulate sum. Otherwise, just form sum. A
5319 constant will have been placed second. */
5320 if (CONSTANT_P (x) && CONSTANT_P (y))
5322 if (GET_CODE (x) == CONST)
5323 x = XEXP (x, 0);
5324 if (GET_CODE (y) == CONST)
5325 y = XEXP (y, 0);
5327 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
5330 return gen_rtx_PLUS (mode, x, y);
5333 /* If ADDR is a sum containing a pseudo register that should be
5334 replaced with a constant (from reg_equiv_constant),
5335 return the result of doing so, and also apply the associative
5336 law so that the result is more likely to be a valid address.
5337 (But it is not guaranteed to be one.)
5339 Note that at most one register is replaced, even if more are
5340 replaceable. Also, we try to put the result into a canonical form
5341 so it is more likely to be a valid address.
5343 In all other cases, return ADDR. */
5345 static rtx
5346 subst_indexed_address (rtx addr)
5348 rtx op0 = 0, op1 = 0, op2 = 0;
5349 rtx tem;
5350 int regno;
5352 if (GET_CODE (addr) == PLUS)
5354 /* Try to find a register to replace. */
5355 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
5356 if (REG_P (op0)
5357 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
5358 && reg_renumber[regno] < 0
5359 && reg_equiv_constant[regno] != 0)
5360 op0 = reg_equiv_constant[regno];
5361 else if (REG_P (op1)
5362 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
5363 && reg_renumber[regno] < 0
5364 && reg_equiv_constant[regno] != 0)
5365 op1 = reg_equiv_constant[regno];
5366 else if (GET_CODE (op0) == PLUS
5367 && (tem = subst_indexed_address (op0)) != op0)
5368 op0 = tem;
5369 else if (GET_CODE (op1) == PLUS
5370 && (tem = subst_indexed_address (op1)) != op1)
5371 op1 = tem;
5372 else
5373 return addr;
5375 /* Pick out up to three things to add. */
5376 if (GET_CODE (op1) == PLUS)
5377 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
5378 else if (GET_CODE (op0) == PLUS)
5379 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
5381 /* Compute the sum. */
5382 if (op2 != 0)
5383 op1 = form_sum (op1, op2);
5384 if (op1 != 0)
5385 op0 = form_sum (op0, op1);
5387 return op0;
5389 return addr;
5392 /* Update the REG_INC notes for an insn. It updates all REG_INC
5393 notes for the instruction which refer to REGNO the to refer
5394 to the reload number.
5396 INSN is the insn for which any REG_INC notes need updating.
5398 REGNO is the register number which has been reloaded.
5400 RELOADNUM is the reload number. */
5402 static void
5403 update_auto_inc_notes (rtx insn ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED,
5404 int reloadnum ATTRIBUTE_UNUSED)
5406 #ifdef AUTO_INC_DEC
5407 rtx link;
5409 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
5410 if (REG_NOTE_KIND (link) == REG_INC
5411 && (int) REGNO (XEXP (link, 0)) == regno)
5412 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5413 #endif
5416 /* Record the pseudo registers we must reload into hard registers in a
5417 subexpression of a would-be memory address, X referring to a value
5418 in mode MODE. (This function is not called if the address we find
5419 is strictly valid.)
5421 CONTEXT = 1 means we are considering regs as index regs,
5422 = 0 means we are considering them as base regs.
5423 OUTER_CODE is the code of the enclosing RTX, typically a MEM, a PLUS,
5424 or an autoinc code.
5425 If CONTEXT == 0 and OUTER_CODE is a PLUS or LO_SUM, then INDEX_CODE
5426 is the code of the index part of the address. Otherwise, pass SCRATCH
5427 for this argument.
5428 OPNUM and TYPE specify the purpose of any reloads made.
5430 IND_LEVELS says how many levels of indirect addressing are
5431 supported at this point in the address.
5433 INSN, if nonzero, is the insn in which we do the reload. It is used
5434 to determine if we may generate output reloads.
5436 We return nonzero if X, as a whole, is reloaded or replaced. */
5438 /* Note that we take shortcuts assuming that no multi-reg machine mode
5439 occurs as part of an address.
5440 Also, this is not fully machine-customizable; it works for machines
5441 such as VAXen and 68000's and 32000's, but other possible machines
5442 could have addressing modes that this does not handle right.
5443 If you add push_reload calls here, you need to make sure gen_reload
5444 handles those cases gracefully. */
5446 static int
5447 find_reloads_address_1 (enum machine_mode mode, rtx x, int context,
5448 enum rtx_code outer_code, enum rtx_code index_code,
5449 rtx *loc, int opnum, enum reload_type type,
5450 int ind_levels, rtx insn)
5452 #define REG_OK_FOR_CONTEXT(CONTEXT, REGNO, MODE, OUTER, INDEX) \
5453 ((CONTEXT) == 0 \
5454 ? regno_ok_for_base_p (REGNO, MODE, OUTER, INDEX) \
5455 : REGNO_OK_FOR_INDEX_P (REGNO))
5457 enum reg_class context_reg_class;
5458 RTX_CODE code = GET_CODE (x);
5460 if (context == 1)
5461 context_reg_class = INDEX_REG_CLASS;
5462 else
5463 context_reg_class = base_reg_class (mode, outer_code, index_code);
5465 switch (code)
5467 case PLUS:
5469 rtx orig_op0 = XEXP (x, 0);
5470 rtx orig_op1 = XEXP (x, 1);
5471 RTX_CODE code0 = GET_CODE (orig_op0);
5472 RTX_CODE code1 = GET_CODE (orig_op1);
5473 rtx op0 = orig_op0;
5474 rtx op1 = orig_op1;
5476 if (GET_CODE (op0) == SUBREG)
5478 op0 = SUBREG_REG (op0);
5479 code0 = GET_CODE (op0);
5480 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5481 op0 = gen_rtx_REG (word_mode,
5482 (REGNO (op0) +
5483 subreg_regno_offset (REGNO (SUBREG_REG (orig_op0)),
5484 GET_MODE (SUBREG_REG (orig_op0)),
5485 SUBREG_BYTE (orig_op0),
5486 GET_MODE (orig_op0))));
5489 if (GET_CODE (op1) == SUBREG)
5491 op1 = SUBREG_REG (op1);
5492 code1 = GET_CODE (op1);
5493 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5494 /* ??? Why is this given op1's mode and above for
5495 ??? op0 SUBREGs we use word_mode? */
5496 op1 = gen_rtx_REG (GET_MODE (op1),
5497 (REGNO (op1) +
5498 subreg_regno_offset (REGNO (SUBREG_REG (orig_op1)),
5499 GET_MODE (SUBREG_REG (orig_op1)),
5500 SUBREG_BYTE (orig_op1),
5501 GET_MODE (orig_op1))));
5503 /* Plus in the index register may be created only as a result of
5504 register rematerialization for expression like &localvar*4. Reload it.
5505 It may be possible to combine the displacement on the outer level,
5506 but it is probably not worthwhile to do so. */
5507 if (context == 1)
5509 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5510 opnum, ADDR_TYPE (type), ind_levels, insn);
5511 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5512 context_reg_class,
5513 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5514 return 1;
5517 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
5518 || code0 == ZERO_EXTEND || code1 == MEM)
5520 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5521 &XEXP (x, 0), opnum, type, ind_levels,
5522 insn);
5523 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5524 &XEXP (x, 1), opnum, type, ind_levels,
5525 insn);
5528 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
5529 || code1 == ZERO_EXTEND || code0 == MEM)
5531 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5532 &XEXP (x, 0), opnum, type, ind_levels,
5533 insn);
5534 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5535 &XEXP (x, 1), opnum, type, ind_levels,
5536 insn);
5539 else if (code0 == CONST_INT || code0 == CONST
5540 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5541 find_reloads_address_1 (mode, orig_op1, 0, PLUS, code0,
5542 &XEXP (x, 1), opnum, type, ind_levels,
5543 insn);
5545 else if (code1 == CONST_INT || code1 == CONST
5546 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5547 find_reloads_address_1 (mode, orig_op0, 0, PLUS, code1,
5548 &XEXP (x, 0), opnum, type, ind_levels,
5549 insn);
5551 else if (code0 == REG && code1 == REG)
5553 if (REGNO_OK_FOR_INDEX_P (REGNO (op1))
5554 && regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5555 return 0;
5556 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0))
5557 && regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5558 return 0;
5559 else if (regno_ok_for_base_p (REGNO (op0), mode, PLUS, REG))
5560 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5561 &XEXP (x, 1), opnum, type, ind_levels,
5562 insn);
5563 else if (REGNO_OK_FOR_INDEX_P (REGNO (op1)))
5564 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5565 &XEXP (x, 0), opnum, type, ind_levels,
5566 insn);
5567 else if (regno_ok_for_base_p (REGNO (op1), mode, PLUS, REG))
5568 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5569 &XEXP (x, 0), opnum, type, ind_levels,
5570 insn);
5571 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0)))
5572 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5573 &XEXP (x, 1), opnum, type, ind_levels,
5574 insn);
5575 else
5577 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5578 &XEXP (x, 0), opnum, type, ind_levels,
5579 insn);
5580 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5581 &XEXP (x, 1), opnum, type, ind_levels,
5582 insn);
5586 else if (code0 == REG)
5588 find_reloads_address_1 (mode, orig_op0, 1, PLUS, SCRATCH,
5589 &XEXP (x, 0), opnum, type, ind_levels,
5590 insn);
5591 find_reloads_address_1 (mode, orig_op1, 0, PLUS, REG,
5592 &XEXP (x, 1), opnum, type, ind_levels,
5593 insn);
5596 else if (code1 == REG)
5598 find_reloads_address_1 (mode, orig_op1, 1, PLUS, SCRATCH,
5599 &XEXP (x, 1), opnum, type, ind_levels,
5600 insn);
5601 find_reloads_address_1 (mode, orig_op0, 0, PLUS, REG,
5602 &XEXP (x, 0), opnum, type, ind_levels,
5603 insn);
5607 return 0;
5609 case POST_MODIFY:
5610 case PRE_MODIFY:
5612 rtx op0 = XEXP (x, 0);
5613 rtx op1 = XEXP (x, 1);
5614 enum rtx_code index_code;
5615 int regno;
5616 int reloadnum;
5618 if (GET_CODE (op1) != PLUS && GET_CODE (op1) != MINUS)
5619 return 0;
5621 /* Currently, we only support {PRE,POST}_MODIFY constructs
5622 where a base register is {inc,dec}remented by the contents
5623 of another register or by a constant value. Thus, these
5624 operands must match. */
5625 gcc_assert (op0 == XEXP (op1, 0));
5627 /* Require index register (or constant). Let's just handle the
5628 register case in the meantime... If the target allows
5629 auto-modify by a constant then we could try replacing a pseudo
5630 register with its equivalent constant where applicable.
5632 We also handle the case where the register was eliminated
5633 resulting in a PLUS subexpression.
5635 If we later decide to reload the whole PRE_MODIFY or
5636 POST_MODIFY, inc_for_reload might clobber the reload register
5637 before reading the index. The index register might therefore
5638 need to live longer than a TYPE reload normally would, so be
5639 conservative and class it as RELOAD_OTHER. */
5640 if ((REG_P (XEXP (op1, 1))
5641 && !REGNO_OK_FOR_INDEX_P (REGNO (XEXP (op1, 1))))
5642 || GET_CODE (XEXP (op1, 1)) == PLUS)
5643 find_reloads_address_1 (mode, XEXP (op1, 1), 1, code, SCRATCH,
5644 &XEXP (op1, 1), opnum, RELOAD_OTHER,
5645 ind_levels, insn);
5647 gcc_assert (REG_P (XEXP (op1, 0)));
5649 regno = REGNO (XEXP (op1, 0));
5650 index_code = GET_CODE (XEXP (op1, 1));
5652 /* A register that is incremented cannot be constant! */
5653 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5654 || reg_equiv_constant[regno] == 0);
5656 /* Handle a register that is equivalent to a memory location
5657 which cannot be addressed directly. */
5658 if (reg_equiv_memory_loc[regno] != 0
5659 && (reg_equiv_address[regno] != 0
5660 || num_not_at_initial_offset))
5662 rtx tem = make_memloc (XEXP (x, 0), regno);
5664 if (reg_equiv_address[regno]
5665 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5667 rtx orig = tem;
5669 /* First reload the memory location's address.
5670 We can't use ADDR_TYPE (type) here, because we need to
5671 write back the value after reading it, hence we actually
5672 need two registers. */
5673 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5674 &XEXP (tem, 0), opnum,
5675 RELOAD_OTHER,
5676 ind_levels, insn);
5678 if (!rtx_equal_p (tem, orig))
5679 push_reg_equiv_alt_mem (regno, tem);
5681 /* Then reload the memory location into a base
5682 register. */
5683 reloadnum = push_reload (tem, tem, &XEXP (x, 0),
5684 &XEXP (op1, 0),
5685 base_reg_class (mode, code,
5686 index_code),
5687 GET_MODE (x), GET_MODE (x), 0,
5688 0, opnum, RELOAD_OTHER);
5690 update_auto_inc_notes (this_insn, regno, reloadnum);
5691 return 0;
5695 if (reg_renumber[regno] >= 0)
5696 regno = reg_renumber[regno];
5698 /* We require a base register here... */
5699 if (!regno_ok_for_base_p (regno, GET_MODE (x), code, index_code))
5701 reloadnum = push_reload (XEXP (op1, 0), XEXP (x, 0),
5702 &XEXP (op1, 0), &XEXP (x, 0),
5703 base_reg_class (mode, code, index_code),
5704 GET_MODE (x), GET_MODE (x), 0, 0,
5705 opnum, RELOAD_OTHER);
5707 update_auto_inc_notes (this_insn, regno, reloadnum);
5708 return 0;
5711 return 0;
5713 case POST_INC:
5714 case POST_DEC:
5715 case PRE_INC:
5716 case PRE_DEC:
5717 if (REG_P (XEXP (x, 0)))
5719 int regno = REGNO (XEXP (x, 0));
5720 int value = 0;
5721 rtx x_orig = x;
5723 /* A register that is incremented cannot be constant! */
5724 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5725 || reg_equiv_constant[regno] == 0);
5727 /* Handle a register that is equivalent to a memory location
5728 which cannot be addressed directly. */
5729 if (reg_equiv_memory_loc[regno] != 0
5730 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5732 rtx tem = make_memloc (XEXP (x, 0), regno);
5733 if (reg_equiv_address[regno]
5734 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5736 rtx orig = tem;
5738 /* First reload the memory location's address.
5739 We can't use ADDR_TYPE (type) here, because we need to
5740 write back the value after reading it, hence we actually
5741 need two registers. */
5742 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5743 &XEXP (tem, 0), opnum, type,
5744 ind_levels, insn);
5745 if (!rtx_equal_p (tem, orig))
5746 push_reg_equiv_alt_mem (regno, tem);
5747 /* Put this inside a new increment-expression. */
5748 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5749 /* Proceed to reload that, as if it contained a register. */
5753 /* If we have a hard register that is ok in this incdec context,
5754 don't make a reload. If the register isn't nice enough for
5755 autoincdec, we can reload it. But, if an autoincrement of a
5756 register that we here verified as playing nice, still outside
5757 isn't "valid", it must be that no autoincrement is "valid".
5758 If that is true and something made an autoincrement anyway,
5759 this must be a special context where one is allowed.
5760 (For example, a "push" instruction.)
5761 We can't improve this address, so leave it alone. */
5763 /* Otherwise, reload the autoincrement into a suitable hard reg
5764 and record how much to increment by. */
5766 if (reg_renumber[regno] >= 0)
5767 regno = reg_renumber[regno];
5768 if (regno >= FIRST_PSEUDO_REGISTER
5769 || !REG_OK_FOR_CONTEXT (context, regno, mode, code,
5770 index_code))
5772 int reloadnum;
5774 /* If we can output the register afterwards, do so, this
5775 saves the extra update.
5776 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5777 CALL_INSN - and it does not set CC0.
5778 But don't do this if we cannot directly address the
5779 memory location, since this will make it harder to
5780 reuse address reloads, and increases register pressure.
5781 Also don't do this if we can probably update x directly. */
5782 rtx equiv = (MEM_P (XEXP (x, 0))
5783 ? XEXP (x, 0)
5784 : reg_equiv_mem[regno]);
5785 int icode = (int) optab_handler (add_optab, Pmode)->insn_code;
5786 if (insn && NONJUMP_INSN_P (insn) && equiv
5787 && memory_operand (equiv, GET_MODE (equiv))
5788 #ifdef HAVE_cc0
5789 && ! sets_cc0_p (PATTERN (insn))
5790 #endif
5791 && ! (icode != CODE_FOR_nothing
5792 && ((*insn_data[icode].operand[0].predicate)
5793 (equiv, Pmode))
5794 && ((*insn_data[icode].operand[1].predicate)
5795 (equiv, Pmode))))
5797 /* We use the original pseudo for loc, so that
5798 emit_reload_insns() knows which pseudo this
5799 reload refers to and updates the pseudo rtx, not
5800 its equivalent memory location, as well as the
5801 corresponding entry in reg_last_reload_reg. */
5802 loc = &XEXP (x_orig, 0);
5803 x = XEXP (x, 0);
5804 reloadnum
5805 = push_reload (x, x, loc, loc,
5806 context_reg_class,
5807 GET_MODE (x), GET_MODE (x), 0, 0,
5808 opnum, RELOAD_OTHER);
5810 else
5812 reloadnum
5813 = push_reload (x, x, loc, (rtx*) 0,
5814 context_reg_class,
5815 GET_MODE (x), GET_MODE (x), 0, 0,
5816 opnum, type);
5817 rld[reloadnum].inc
5818 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5820 value = 1;
5823 update_auto_inc_notes (this_insn, REGNO (XEXP (x_orig, 0)),
5824 reloadnum);
5826 return value;
5828 return 0;
5830 case TRUNCATE:
5831 case SIGN_EXTEND:
5832 case ZERO_EXTEND:
5833 /* Look for parts to reload in the inner expression and reload them
5834 too, in addition to this operation. Reloading all inner parts in
5835 addition to this one shouldn't be necessary, but at this point,
5836 we don't know if we can possibly omit any part that *can* be
5837 reloaded. Targets that are better off reloading just either part
5838 (or perhaps even a different part of an outer expression), should
5839 define LEGITIMIZE_RELOAD_ADDRESS. */
5840 find_reloads_address_1 (GET_MODE (XEXP (x, 0)), XEXP (x, 0),
5841 context, code, SCRATCH, &XEXP (x, 0), opnum,
5842 type, ind_levels, insn);
5843 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5844 context_reg_class,
5845 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5846 return 1;
5848 case MEM:
5849 /* This is probably the result of a substitution, by eliminate_regs, of
5850 an equivalent address for a pseudo that was not allocated to a hard
5851 register. Verify that the specified address is valid and reload it
5852 into a register.
5854 Since we know we are going to reload this item, don't decrement for
5855 the indirection level.
5857 Note that this is actually conservative: it would be slightly more
5858 efficient to use the value of SPILL_INDIRECT_LEVELS from
5859 reload1.c here. */
5861 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5862 opnum, ADDR_TYPE (type), ind_levels, insn);
5863 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5864 context_reg_class,
5865 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5866 return 1;
5868 case REG:
5870 int regno = REGNO (x);
5872 if (reg_equiv_constant[regno] != 0)
5874 find_reloads_address_part (reg_equiv_constant[regno], loc,
5875 context_reg_class,
5876 GET_MODE (x), opnum, type, ind_levels);
5877 return 1;
5880 #if 0 /* This might screw code in reload1.c to delete prior output-reload
5881 that feeds this insn. */
5882 if (reg_equiv_mem[regno] != 0)
5884 push_reload (reg_equiv_mem[regno], NULL_RTX, loc, (rtx*) 0,
5885 context_reg_class,
5886 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5887 return 1;
5889 #endif
5891 if (reg_equiv_memory_loc[regno]
5892 && (reg_equiv_address[regno] != 0 || num_not_at_initial_offset))
5894 rtx tem = make_memloc (x, regno);
5895 if (reg_equiv_address[regno] != 0
5896 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
5898 x = tem;
5899 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5900 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5901 ind_levels, insn);
5902 if (!rtx_equal_p (x, tem))
5903 push_reg_equiv_alt_mem (regno, x);
5907 if (reg_renumber[regno] >= 0)
5908 regno = reg_renumber[regno];
5910 if (regno >= FIRST_PSEUDO_REGISTER
5911 || !REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5912 index_code))
5914 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5915 context_reg_class,
5916 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5917 return 1;
5920 /* If a register appearing in an address is the subject of a CLOBBER
5921 in this insn, reload it into some other register to be safe.
5922 The CLOBBER is supposed to make the register unavailable
5923 from before this insn to after it. */
5924 if (regno_clobbered_p (regno, this_insn, GET_MODE (x), 0))
5926 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5927 context_reg_class,
5928 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5929 return 1;
5932 return 0;
5934 case SUBREG:
5935 if (REG_P (SUBREG_REG (x)))
5937 /* If this is a SUBREG of a hard register and the resulting register
5938 is of the wrong class, reload the whole SUBREG. This avoids
5939 needless copies if SUBREG_REG is multi-word. */
5940 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5942 int regno ATTRIBUTE_UNUSED = subreg_regno (x);
5944 if (!REG_OK_FOR_CONTEXT (context, regno, mode, outer_code,
5945 index_code))
5947 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5948 context_reg_class,
5949 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5950 return 1;
5953 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
5954 is larger than the class size, then reload the whole SUBREG. */
5955 else
5957 enum reg_class rclass = context_reg_class;
5958 if ((unsigned) CLASS_MAX_NREGS (rclass, GET_MODE (SUBREG_REG (x)))
5959 > reg_class_size[rclass])
5961 x = find_reloads_subreg_address (x, 0, opnum,
5962 ADDR_TYPE (type),
5963 ind_levels, insn);
5964 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
5965 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5966 return 1;
5970 break;
5972 default:
5973 break;
5977 const char *fmt = GET_RTX_FORMAT (code);
5978 int i;
5980 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5982 if (fmt[i] == 'e')
5983 /* Pass SCRATCH for INDEX_CODE, since CODE can never be a PLUS once
5984 we get here. */
5985 find_reloads_address_1 (mode, XEXP (x, i), context, code, SCRATCH,
5986 &XEXP (x, i), opnum, type, ind_levels, insn);
5990 #undef REG_OK_FOR_CONTEXT
5991 return 0;
5994 /* X, which is found at *LOC, is a part of an address that needs to be
5995 reloaded into a register of class RCLASS. If X is a constant, or if
5996 X is a PLUS that contains a constant, check that the constant is a
5997 legitimate operand and that we are supposed to be able to load
5998 it into the register.
6000 If not, force the constant into memory and reload the MEM instead.
6002 MODE is the mode to use, in case X is an integer constant.
6004 OPNUM and TYPE describe the purpose of any reloads made.
6006 IND_LEVELS says how many levels of indirect addressing this machine
6007 supports. */
6009 static void
6010 find_reloads_address_part (rtx x, rtx *loc, enum reg_class rclass,
6011 enum machine_mode mode, int opnum,
6012 enum reload_type type, int ind_levels)
6014 if (CONSTANT_P (x)
6015 && (! LEGITIMATE_CONSTANT_P (x)
6016 || PREFERRED_RELOAD_CLASS (x, rclass) == NO_REGS))
6018 x = force_const_mem (mode, x);
6019 find_reloads_address (mode, &x, XEXP (x, 0), &XEXP (x, 0),
6020 opnum, type, ind_levels, 0);
6023 else if (GET_CODE (x) == PLUS
6024 && CONSTANT_P (XEXP (x, 1))
6025 && (! LEGITIMATE_CONSTANT_P (XEXP (x, 1))
6026 || PREFERRED_RELOAD_CLASS (XEXP (x, 1), rclass) == NO_REGS))
6028 rtx tem;
6030 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
6031 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
6032 find_reloads_address (mode, &XEXP (x, 1), XEXP (tem, 0), &XEXP (tem, 0),
6033 opnum, type, ind_levels, 0);
6036 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6037 mode, VOIDmode, 0, 0, opnum, type);
6040 /* X, a subreg of a pseudo, is a part of an address that needs to be
6041 reloaded.
6043 If the pseudo is equivalent to a memory location that cannot be directly
6044 addressed, make the necessary address reloads.
6046 If address reloads have been necessary, or if the address is changed
6047 by register elimination, return the rtx of the memory location;
6048 otherwise, return X.
6050 If FORCE_REPLACE is nonzero, unconditionally replace the subreg with the
6051 memory location.
6053 OPNUM and TYPE identify the purpose of the reload.
6055 IND_LEVELS says how many levels of indirect addressing are
6056 supported at this point in the address.
6058 INSN, if nonzero, is the insn in which we do the reload. It is used
6059 to determine where to put USEs for pseudos that we have to replace with
6060 stack slots. */
6062 static rtx
6063 find_reloads_subreg_address (rtx x, int force_replace, int opnum,
6064 enum reload_type type, int ind_levels, rtx insn)
6066 int regno = REGNO (SUBREG_REG (x));
6068 if (reg_equiv_memory_loc[regno])
6070 /* If the address is not directly addressable, or if the address is not
6071 offsettable, then it must be replaced. */
6072 if (! force_replace
6073 && (reg_equiv_address[regno]
6074 || ! offsettable_memref_p (reg_equiv_mem[regno])))
6075 force_replace = 1;
6077 if (force_replace || num_not_at_initial_offset)
6079 rtx tem = make_memloc (SUBREG_REG (x), regno);
6081 /* If the address changes because of register elimination, then
6082 it must be replaced. */
6083 if (force_replace
6084 || ! rtx_equal_p (tem, reg_equiv_mem[regno]))
6086 unsigned outer_size = GET_MODE_SIZE (GET_MODE (x));
6087 unsigned inner_size = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
6088 int offset;
6089 rtx orig = tem;
6090 int reloaded;
6092 /* For big-endian paradoxical subregs, SUBREG_BYTE does not
6093 hold the correct (negative) byte offset. */
6094 if (BYTES_BIG_ENDIAN && outer_size > inner_size)
6095 offset = inner_size - outer_size;
6096 else
6097 offset = SUBREG_BYTE (x);
6099 XEXP (tem, 0) = plus_constant (XEXP (tem, 0), offset);
6100 PUT_MODE (tem, GET_MODE (x));
6101 if (MEM_OFFSET (tem))
6102 set_mem_offset (tem, plus_constant (MEM_OFFSET (tem), offset));
6104 /* If this was a paradoxical subreg that we replaced, the
6105 resulting memory must be sufficiently aligned to allow
6106 us to widen the mode of the memory. */
6107 if (outer_size > inner_size)
6109 rtx base;
6111 base = XEXP (tem, 0);
6112 if (GET_CODE (base) == PLUS)
6114 if (GET_CODE (XEXP (base, 1)) == CONST_INT
6115 && INTVAL (XEXP (base, 1)) % outer_size != 0)
6116 return x;
6117 base = XEXP (base, 0);
6119 if (!REG_P (base)
6120 || (REGNO_POINTER_ALIGN (REGNO (base))
6121 < outer_size * BITS_PER_UNIT))
6122 return x;
6125 reloaded = find_reloads_address (GET_MODE (tem), &tem,
6126 XEXP (tem, 0), &XEXP (tem, 0),
6127 opnum, type, ind_levels, insn);
6128 /* ??? Do we need to handle nonzero offsets somehow? */
6129 if (!offset && !rtx_equal_p (tem, orig))
6130 push_reg_equiv_alt_mem (regno, tem);
6132 /* For some processors an address may be valid in the
6133 original mode but not in a smaller mode. For
6134 example, ARM accepts a scaled index register in
6135 SImode but not in HImode. Similarly, the address may
6136 have been valid before the subreg offset was added,
6137 but not afterwards. find_reloads_address
6138 assumes that we pass it a valid address, and doesn't
6139 force a reload. This will probably be fine if
6140 find_reloads_address finds some reloads. But if it
6141 doesn't find any, then we may have just converted a
6142 valid address into an invalid one. Check for that
6143 here. */
6144 if (reloaded == 0
6145 && !strict_memory_address_p (GET_MODE (tem),
6146 XEXP (tem, 0)))
6147 push_reload (XEXP (tem, 0), NULL_RTX, &XEXP (tem, 0), (rtx*) 0,
6148 base_reg_class (GET_MODE (tem), MEM, SCRATCH),
6149 GET_MODE (XEXP (tem, 0)), VOIDmode, 0, 0,
6150 opnum, type);
6152 /* If this is not a toplevel operand, find_reloads doesn't see
6153 this substitution. We have to emit a USE of the pseudo so
6154 that delete_output_reload can see it. */
6155 if (replace_reloads && recog_data.operand[opnum] != x)
6156 /* We mark the USE with QImode so that we recognize it
6157 as one that can be safely deleted at the end of
6158 reload. */
6159 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode,
6160 SUBREG_REG (x)),
6161 insn), QImode);
6162 x = tem;
6166 return x;
6169 /* Substitute into the current INSN the registers into which we have reloaded
6170 the things that need reloading. The array `replacements'
6171 contains the locations of all pointers that must be changed
6172 and says what to replace them with.
6174 Return the rtx that X translates into; usually X, but modified. */
6176 void
6177 subst_reloads (rtx insn)
6179 int i;
6181 for (i = 0; i < n_replacements; i++)
6183 struct replacement *r = &replacements[i];
6184 rtx reloadreg = rld[r->what].reg_rtx;
6185 if (reloadreg)
6187 #ifdef DEBUG_RELOAD
6188 /* This checking takes a very long time on some platforms
6189 causing the gcc.c-torture/compile/limits-fnargs.c test
6190 to time out during testing. See PR 31850.
6192 Internal consistency test. Check that we don't modify
6193 anything in the equivalence arrays. Whenever something from
6194 those arrays needs to be reloaded, it must be unshared before
6195 being substituted into; the equivalence must not be modified.
6196 Otherwise, if the equivalence is used after that, it will
6197 have been modified, and the thing substituted (probably a
6198 register) is likely overwritten and not a usable equivalence. */
6199 int check_regno;
6201 for (check_regno = 0; check_regno < max_regno; check_regno++)
6203 #define CHECK_MODF(ARRAY) \
6204 gcc_assert (!ARRAY[check_regno] \
6205 || !loc_mentioned_in_p (r->where, \
6206 ARRAY[check_regno]))
6208 CHECK_MODF (reg_equiv_constant);
6209 CHECK_MODF (reg_equiv_memory_loc);
6210 CHECK_MODF (reg_equiv_address);
6211 CHECK_MODF (reg_equiv_mem);
6212 #undef CHECK_MODF
6214 #endif /* DEBUG_RELOAD */
6216 /* If we're replacing a LABEL_REF with a register, there must
6217 already be an indication (to e.g. flow) which label this
6218 register refers to. */
6219 gcc_assert (GET_CODE (*r->where) != LABEL_REF
6220 || !JUMP_P (insn)
6221 || find_reg_note (insn,
6222 REG_LABEL_OPERAND,
6223 XEXP (*r->where, 0))
6224 || label_is_jump_target_p (XEXP (*r->where, 0), insn));
6226 /* Encapsulate RELOADREG so its machine mode matches what
6227 used to be there. Note that gen_lowpart_common will
6228 do the wrong thing if RELOADREG is multi-word. RELOADREG
6229 will always be a REG here. */
6230 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
6231 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6233 /* If we are putting this into a SUBREG and RELOADREG is a
6234 SUBREG, we would be making nested SUBREGs, so we have to fix
6235 this up. Note that r->where == &SUBREG_REG (*r->subreg_loc). */
6237 if (r->subreg_loc != 0 && GET_CODE (reloadreg) == SUBREG)
6239 if (GET_MODE (*r->subreg_loc)
6240 == GET_MODE (SUBREG_REG (reloadreg)))
6241 *r->subreg_loc = SUBREG_REG (reloadreg);
6242 else
6244 int final_offset =
6245 SUBREG_BYTE (*r->subreg_loc) + SUBREG_BYTE (reloadreg);
6247 /* When working with SUBREGs the rule is that the byte
6248 offset must be a multiple of the SUBREG's mode. */
6249 final_offset = (final_offset /
6250 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6251 final_offset = (final_offset *
6252 GET_MODE_SIZE (GET_MODE (*r->subreg_loc)));
6254 *r->where = SUBREG_REG (reloadreg);
6255 SUBREG_BYTE (*r->subreg_loc) = final_offset;
6258 else
6259 *r->where = reloadreg;
6261 /* If reload got no reg and isn't optional, something's wrong. */
6262 else
6263 gcc_assert (rld[r->what].optional);
6267 /* Make a copy of any replacements being done into X and move those
6268 copies to locations in Y, a copy of X. */
6270 void
6271 copy_replacements (rtx x, rtx y)
6273 /* We can't support X being a SUBREG because we might then need to know its
6274 location if something inside it was replaced. */
6275 gcc_assert (GET_CODE (x) != SUBREG);
6277 copy_replacements_1 (&x, &y, n_replacements);
6280 static void
6281 copy_replacements_1 (rtx *px, rtx *py, int orig_replacements)
6283 int i, j;
6284 rtx x, y;
6285 struct replacement *r;
6286 enum rtx_code code;
6287 const char *fmt;
6289 for (j = 0; j < orig_replacements; j++)
6291 if (replacements[j].subreg_loc == px)
6293 r = &replacements[n_replacements++];
6294 r->where = replacements[j].where;
6295 r->subreg_loc = py;
6296 r->what = replacements[j].what;
6297 r->mode = replacements[j].mode;
6299 else if (replacements[j].where == px)
6301 r = &replacements[n_replacements++];
6302 r->where = py;
6303 r->subreg_loc = 0;
6304 r->what = replacements[j].what;
6305 r->mode = replacements[j].mode;
6309 x = *px;
6310 y = *py;
6311 code = GET_CODE (x);
6312 fmt = GET_RTX_FORMAT (code);
6314 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6316 if (fmt[i] == 'e')
6317 copy_replacements_1 (&XEXP (x, i), &XEXP (y, i), orig_replacements);
6318 else if (fmt[i] == 'E')
6319 for (j = XVECLEN (x, i); --j >= 0; )
6320 copy_replacements_1 (&XVECEXP (x, i, j), &XVECEXP (y, i, j),
6321 orig_replacements);
6325 /* Change any replacements being done to *X to be done to *Y. */
6327 void
6328 move_replacements (rtx *x, rtx *y)
6330 int i;
6332 for (i = 0; i < n_replacements; i++)
6333 if (replacements[i].subreg_loc == x)
6334 replacements[i].subreg_loc = y;
6335 else if (replacements[i].where == x)
6337 replacements[i].where = y;
6338 replacements[i].subreg_loc = 0;
6342 /* If LOC was scheduled to be replaced by something, return the replacement.
6343 Otherwise, return *LOC. */
6346 find_replacement (rtx *loc)
6348 struct replacement *r;
6350 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
6352 rtx reloadreg = rld[r->what].reg_rtx;
6354 if (reloadreg && r->where == loc)
6356 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6357 reloadreg = gen_rtx_REG (r->mode, REGNO (reloadreg));
6359 return reloadreg;
6361 else if (reloadreg && r->subreg_loc == loc)
6363 /* RELOADREG must be either a REG or a SUBREG.
6365 ??? Is it actually still ever a SUBREG? If so, why? */
6367 if (REG_P (reloadreg))
6368 return gen_rtx_REG (GET_MODE (*loc),
6369 (REGNO (reloadreg) +
6370 subreg_regno_offset (REGNO (SUBREG_REG (*loc)),
6371 GET_MODE (SUBREG_REG (*loc)),
6372 SUBREG_BYTE (*loc),
6373 GET_MODE (*loc))));
6374 else if (GET_MODE (reloadreg) == GET_MODE (*loc))
6375 return reloadreg;
6376 else
6378 int final_offset = SUBREG_BYTE (reloadreg) + SUBREG_BYTE (*loc);
6380 /* When working with SUBREGs the rule is that the byte
6381 offset must be a multiple of the SUBREG's mode. */
6382 final_offset = (final_offset / GET_MODE_SIZE (GET_MODE (*loc)));
6383 final_offset = (final_offset * GET_MODE_SIZE (GET_MODE (*loc)));
6384 return gen_rtx_SUBREG (GET_MODE (*loc), SUBREG_REG (reloadreg),
6385 final_offset);
6390 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
6391 what's inside and make a new rtl if so. */
6392 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
6393 || GET_CODE (*loc) == MULT)
6395 rtx x = find_replacement (&XEXP (*loc, 0));
6396 rtx y = find_replacement (&XEXP (*loc, 1));
6398 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
6399 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
6402 return *loc;
6405 /* Return nonzero if register in range [REGNO, ENDREGNO)
6406 appears either explicitly or implicitly in X
6407 other than being stored into (except for earlyclobber operands).
6409 References contained within the substructure at LOC do not count.
6410 LOC may be zero, meaning don't ignore anything.
6412 This is similar to refers_to_regno_p in rtlanal.c except that we
6413 look at equivalences for pseudos that didn't get hard registers. */
6415 static int
6416 refers_to_regno_for_reload_p (unsigned int regno, unsigned int endregno,
6417 rtx x, rtx *loc)
6419 int i;
6420 unsigned int r;
6421 RTX_CODE code;
6422 const char *fmt;
6424 if (x == 0)
6425 return 0;
6427 repeat:
6428 code = GET_CODE (x);
6430 switch (code)
6432 case REG:
6433 r = REGNO (x);
6435 /* If this is a pseudo, a hard register must not have been allocated.
6436 X must therefore either be a constant or be in memory. */
6437 if (r >= FIRST_PSEUDO_REGISTER)
6439 if (reg_equiv_memory_loc[r])
6440 return refers_to_regno_for_reload_p (regno, endregno,
6441 reg_equiv_memory_loc[r],
6442 (rtx*) 0);
6444 gcc_assert (reg_equiv_constant[r] || reg_equiv_invariant[r]);
6445 return 0;
6448 return (endregno > r
6449 && regno < r + (r < FIRST_PSEUDO_REGISTER
6450 ? hard_regno_nregs[r][GET_MODE (x)]
6451 : 1));
6453 case SUBREG:
6454 /* If this is a SUBREG of a hard reg, we can see exactly which
6455 registers are being modified. Otherwise, handle normally. */
6456 if (REG_P (SUBREG_REG (x))
6457 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
6459 unsigned int inner_regno = subreg_regno (x);
6460 unsigned int inner_endregno
6461 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
6462 ? subreg_nregs (x) : 1);
6464 return endregno > inner_regno && regno < inner_endregno;
6466 break;
6468 case CLOBBER:
6469 case SET:
6470 if (&SET_DEST (x) != loc
6471 /* Note setting a SUBREG counts as referring to the REG it is in for
6472 a pseudo but not for hard registers since we can
6473 treat each word individually. */
6474 && ((GET_CODE (SET_DEST (x)) == SUBREG
6475 && loc != &SUBREG_REG (SET_DEST (x))
6476 && REG_P (SUBREG_REG (SET_DEST (x)))
6477 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
6478 && refers_to_regno_for_reload_p (regno, endregno,
6479 SUBREG_REG (SET_DEST (x)),
6480 loc))
6481 /* If the output is an earlyclobber operand, this is
6482 a conflict. */
6483 || ((!REG_P (SET_DEST (x))
6484 || earlyclobber_operand_p (SET_DEST (x)))
6485 && refers_to_regno_for_reload_p (regno, endregno,
6486 SET_DEST (x), loc))))
6487 return 1;
6489 if (code == CLOBBER || loc == &SET_SRC (x))
6490 return 0;
6491 x = SET_SRC (x);
6492 goto repeat;
6494 default:
6495 break;
6498 /* X does not match, so try its subexpressions. */
6500 fmt = GET_RTX_FORMAT (code);
6501 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6503 if (fmt[i] == 'e' && loc != &XEXP (x, i))
6505 if (i == 0)
6507 x = XEXP (x, 0);
6508 goto repeat;
6510 else
6511 if (refers_to_regno_for_reload_p (regno, endregno,
6512 XEXP (x, i), loc))
6513 return 1;
6515 else if (fmt[i] == 'E')
6517 int j;
6518 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6519 if (loc != &XVECEXP (x, i, j)
6520 && refers_to_regno_for_reload_p (regno, endregno,
6521 XVECEXP (x, i, j), loc))
6522 return 1;
6525 return 0;
6528 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
6529 we check if any register number in X conflicts with the relevant register
6530 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
6531 contains a MEM (we don't bother checking for memory addresses that can't
6532 conflict because we expect this to be a rare case.
6534 This function is similar to reg_overlap_mentioned_p in rtlanal.c except
6535 that we look at equivalences for pseudos that didn't get hard registers. */
6538 reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
6540 int regno, endregno;
6542 /* Overly conservative. */
6543 if (GET_CODE (x) == STRICT_LOW_PART
6544 || GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
6545 x = XEXP (x, 0);
6547 /* If either argument is a constant, then modifying X can not affect IN. */
6548 if (CONSTANT_P (x) || CONSTANT_P (in))
6549 return 0;
6550 else if (GET_CODE (x) == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
6551 return refers_to_mem_for_reload_p (in);
6552 else if (GET_CODE (x) == SUBREG)
6554 regno = REGNO (SUBREG_REG (x));
6555 if (regno < FIRST_PSEUDO_REGISTER)
6556 regno += subreg_regno_offset (REGNO (SUBREG_REG (x)),
6557 GET_MODE (SUBREG_REG (x)),
6558 SUBREG_BYTE (x),
6559 GET_MODE (x));
6560 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
6561 ? subreg_nregs (x) : 1);
6563 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6565 else if (REG_P (x))
6567 regno = REGNO (x);
6569 /* If this is a pseudo, it must not have been assigned a hard register.
6570 Therefore, it must either be in memory or be a constant. */
6572 if (regno >= FIRST_PSEUDO_REGISTER)
6574 if (reg_equiv_memory_loc[regno])
6575 return refers_to_mem_for_reload_p (in);
6576 gcc_assert (reg_equiv_constant[regno]);
6577 return 0;
6580 endregno = END_HARD_REGNO (x);
6582 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6584 else if (MEM_P (x))
6585 return refers_to_mem_for_reload_p (in);
6586 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
6587 || GET_CODE (x) == CC0)
6588 return reg_mentioned_p (x, in);
6589 else
6591 gcc_assert (GET_CODE (x) == PLUS);
6593 /* We actually want to know if X is mentioned somewhere inside IN.
6594 We must not say that (plus (sp) (const_int 124)) is in
6595 (plus (sp) (const_int 64)), since that can lead to incorrect reload
6596 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
6597 into a RELOAD_OTHER on behalf of another RELOAD_OTHER. */
6598 while (MEM_P (in))
6599 in = XEXP (in, 0);
6600 if (REG_P (in))
6601 return 0;
6602 else if (GET_CODE (in) == PLUS)
6603 return (rtx_equal_p (x, in)
6604 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
6605 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
6606 else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
6607 || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
6610 gcc_unreachable ();
6613 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
6614 registers. */
6616 static int
6617 refers_to_mem_for_reload_p (rtx x)
6619 const char *fmt;
6620 int i;
6622 if (MEM_P (x))
6623 return 1;
6625 if (REG_P (x))
6626 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
6627 && reg_equiv_memory_loc[REGNO (x)]);
6629 fmt = GET_RTX_FORMAT (GET_CODE (x));
6630 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
6631 if (fmt[i] == 'e'
6632 && (MEM_P (XEXP (x, i))
6633 || refers_to_mem_for_reload_p (XEXP (x, i))))
6634 return 1;
6636 return 0;
6639 /* Check the insns before INSN to see if there is a suitable register
6640 containing the same value as GOAL.
6641 If OTHER is -1, look for a register in class RCLASS.
6642 Otherwise, just see if register number OTHER shares GOAL's value.
6644 Return an rtx for the register found, or zero if none is found.
6646 If RELOAD_REG_P is (short *)1,
6647 we reject any hard reg that appears in reload_reg_rtx
6648 because such a hard reg is also needed coming into this insn.
6650 If RELOAD_REG_P is any other nonzero value,
6651 it is a vector indexed by hard reg number
6652 and we reject any hard reg whose element in the vector is nonnegative
6653 as well as any that appears in reload_reg_rtx.
6655 If GOAL is zero, then GOALREG is a register number; we look
6656 for an equivalent for that register.
6658 MODE is the machine mode of the value we want an equivalence for.
6659 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
6661 This function is used by jump.c as well as in the reload pass.
6663 If GOAL is the sum of the stack pointer and a constant, we treat it
6664 as if it were a constant except that sp is required to be unchanging. */
6667 find_equiv_reg (rtx goal, rtx insn, enum reg_class rclass, int other,
6668 short *reload_reg_p, int goalreg, enum machine_mode mode)
6670 rtx p = insn;
6671 rtx goaltry, valtry, value, where;
6672 rtx pat;
6673 int regno = -1;
6674 int valueno;
6675 int goal_mem = 0;
6676 int goal_const = 0;
6677 int goal_mem_addr_varies = 0;
6678 int need_stable_sp = 0;
6679 int nregs;
6680 int valuenregs;
6681 int num = 0;
6683 if (goal == 0)
6684 regno = goalreg;
6685 else if (REG_P (goal))
6686 regno = REGNO (goal);
6687 else if (MEM_P (goal))
6689 enum rtx_code code = GET_CODE (XEXP (goal, 0));
6690 if (MEM_VOLATILE_P (goal))
6691 return 0;
6692 if (flag_float_store && SCALAR_FLOAT_MODE_P (GET_MODE (goal)))
6693 return 0;
6694 /* An address with side effects must be reexecuted. */
6695 switch (code)
6697 case POST_INC:
6698 case PRE_INC:
6699 case POST_DEC:
6700 case PRE_DEC:
6701 case POST_MODIFY:
6702 case PRE_MODIFY:
6703 return 0;
6704 default:
6705 break;
6707 goal_mem = 1;
6709 else if (CONSTANT_P (goal))
6710 goal_const = 1;
6711 else if (GET_CODE (goal) == PLUS
6712 && XEXP (goal, 0) == stack_pointer_rtx
6713 && CONSTANT_P (XEXP (goal, 1)))
6714 goal_const = need_stable_sp = 1;
6715 else if (GET_CODE (goal) == PLUS
6716 && XEXP (goal, 0) == frame_pointer_rtx
6717 && CONSTANT_P (XEXP (goal, 1)))
6718 goal_const = 1;
6719 else
6720 return 0;
6722 num = 0;
6723 /* Scan insns back from INSN, looking for one that copies
6724 a value into or out of GOAL.
6725 Stop and give up if we reach a label. */
6727 while (1)
6729 p = PREV_INSN (p);
6730 num++;
6731 if (p == 0 || LABEL_P (p)
6732 || num > PARAM_VALUE (PARAM_MAX_RELOAD_SEARCH_INSNS))
6733 return 0;
6735 if (NONJUMP_INSN_P (p)
6736 /* If we don't want spill regs ... */
6737 && (! (reload_reg_p != 0
6738 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6739 /* ... then ignore insns introduced by reload; they aren't
6740 useful and can cause results in reload_as_needed to be
6741 different from what they were when calculating the need for
6742 spills. If we notice an input-reload insn here, we will
6743 reject it below, but it might hide a usable equivalent.
6744 That makes bad code. It may even fail: perhaps no reg was
6745 spilled for this insn because it was assumed we would find
6746 that equivalent. */
6747 || INSN_UID (p) < reload_first_uid))
6749 rtx tem;
6750 pat = single_set (p);
6752 /* First check for something that sets some reg equal to GOAL. */
6753 if (pat != 0
6754 && ((regno >= 0
6755 && true_regnum (SET_SRC (pat)) == regno
6756 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6758 (regno >= 0
6759 && true_regnum (SET_DEST (pat)) == regno
6760 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6762 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6763 /* When looking for stack pointer + const,
6764 make sure we don't use a stack adjust. */
6765 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6766 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6767 || (goal_mem
6768 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6769 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6770 || (goal_mem
6771 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6772 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6773 /* If we are looking for a constant,
6774 and something equivalent to that constant was copied
6775 into a reg, we can use that reg. */
6776 || (goal_const && REG_NOTES (p) != 0
6777 && (tem = find_reg_note (p, REG_EQUIV, NULL_RTX))
6778 && ((rtx_equal_p (XEXP (tem, 0), goal)
6779 && (valueno
6780 = true_regnum (valtry = SET_DEST (pat))) >= 0)
6781 || (REG_P (SET_DEST (pat))
6782 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6783 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6784 && GET_CODE (goal) == CONST_INT
6785 && 0 != (goaltry
6786 = operand_subword (XEXP (tem, 0), 0, 0,
6787 VOIDmode))
6788 && rtx_equal_p (goal, goaltry)
6789 && (valtry
6790 = operand_subword (SET_DEST (pat), 0, 0,
6791 VOIDmode))
6792 && (valueno = true_regnum (valtry)) >= 0)))
6793 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6794 NULL_RTX))
6795 && REG_P (SET_DEST (pat))
6796 && GET_CODE (XEXP (tem, 0)) == CONST_DOUBLE
6797 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6798 && GET_CODE (goal) == CONST_INT
6799 && 0 != (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6800 VOIDmode))
6801 && rtx_equal_p (goal, goaltry)
6802 && (valtry
6803 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6804 && (valueno = true_regnum (valtry)) >= 0)))
6806 if (other >= 0)
6808 if (valueno != other)
6809 continue;
6811 else if ((unsigned) valueno >= FIRST_PSEUDO_REGISTER)
6812 continue;
6813 else if (!in_hard_reg_set_p (reg_class_contents[(int) rclass],
6814 mode, valueno))
6815 continue;
6816 value = valtry;
6817 where = p;
6818 break;
6823 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6824 (or copying VALUE into GOAL, if GOAL is also a register).
6825 Now verify that VALUE is really valid. */
6827 /* VALUENO is the register number of VALUE; a hard register. */
6829 /* Don't try to re-use something that is killed in this insn. We want
6830 to be able to trust REG_UNUSED notes. */
6831 if (REG_NOTES (where) != 0 && find_reg_note (where, REG_UNUSED, value))
6832 return 0;
6834 /* If we propose to get the value from the stack pointer or if GOAL is
6835 a MEM based on the stack pointer, we need a stable SP. */
6836 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6837 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6838 goal)))
6839 need_stable_sp = 1;
6841 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6842 if (GET_MODE (value) != mode)
6843 return 0;
6845 /* Reject VALUE if it was loaded from GOAL
6846 and is also a register that appears in the address of GOAL. */
6848 if (goal_mem && value == SET_DEST (single_set (where))
6849 && refers_to_regno_for_reload_p (valueno, end_hard_regno (mode, valueno),
6850 goal, (rtx*) 0))
6851 return 0;
6853 /* Reject registers that overlap GOAL. */
6855 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6856 nregs = hard_regno_nregs[regno][mode];
6857 else
6858 nregs = 1;
6859 valuenregs = hard_regno_nregs[valueno][mode];
6861 if (!goal_mem && !goal_const
6862 && regno + nregs > valueno && regno < valueno + valuenregs)
6863 return 0;
6865 /* Reject VALUE if it is one of the regs reserved for reloads.
6866 Reload1 knows how to reuse them anyway, and it would get
6867 confused if we allocated one without its knowledge.
6868 (Now that insns introduced by reload are ignored above,
6869 this case shouldn't happen, but I'm not positive.) */
6871 if (reload_reg_p != 0 && reload_reg_p != (short *) (HOST_WIDE_INT) 1)
6873 int i;
6874 for (i = 0; i < valuenregs; ++i)
6875 if (reload_reg_p[valueno + i] >= 0)
6876 return 0;
6879 /* Reject VALUE if it is a register being used for an input reload
6880 even if it is not one of those reserved. */
6882 if (reload_reg_p != 0)
6884 int i;
6885 for (i = 0; i < n_reloads; i++)
6886 if (rld[i].reg_rtx != 0 && rld[i].in)
6888 int regno1 = REGNO (rld[i].reg_rtx);
6889 int nregs1 = hard_regno_nregs[regno1]
6890 [GET_MODE (rld[i].reg_rtx)];
6891 if (regno1 < valueno + valuenregs
6892 && regno1 + nregs1 > valueno)
6893 return 0;
6897 if (goal_mem)
6898 /* We must treat frame pointer as varying here,
6899 since it can vary--in a nonlocal goto as generated by expand_goto. */
6900 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6902 /* Now verify that the values of GOAL and VALUE remain unaltered
6903 until INSN is reached. */
6905 p = insn;
6906 while (1)
6908 p = PREV_INSN (p);
6909 if (p == where)
6910 return value;
6912 /* Don't trust the conversion past a function call
6913 if either of the two is in a call-clobbered register, or memory. */
6914 if (CALL_P (p))
6916 int i;
6918 if (goal_mem || need_stable_sp)
6919 return 0;
6921 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6922 for (i = 0; i < nregs; ++i)
6923 if (call_used_regs[regno + i]
6924 || HARD_REGNO_CALL_PART_CLOBBERED (regno + i, mode))
6925 return 0;
6927 if (valueno >= 0 && valueno < FIRST_PSEUDO_REGISTER)
6928 for (i = 0; i < valuenregs; ++i)
6929 if (call_used_regs[valueno + i]
6930 || HARD_REGNO_CALL_PART_CLOBBERED (valueno + i, mode))
6931 return 0;
6934 if (INSN_P (p))
6936 pat = PATTERN (p);
6938 /* Watch out for unspec_volatile, and volatile asms. */
6939 if (volatile_insn_p (pat))
6940 return 0;
6942 /* If this insn P stores in either GOAL or VALUE, return 0.
6943 If GOAL is a memory ref and this insn writes memory, return 0.
6944 If GOAL is a memory ref and its address is not constant,
6945 and this insn P changes a register used in GOAL, return 0. */
6947 if (GET_CODE (pat) == COND_EXEC)
6948 pat = COND_EXEC_CODE (pat);
6949 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6951 rtx dest = SET_DEST (pat);
6952 while (GET_CODE (dest) == SUBREG
6953 || GET_CODE (dest) == ZERO_EXTRACT
6954 || GET_CODE (dest) == STRICT_LOW_PART)
6955 dest = XEXP (dest, 0);
6956 if (REG_P (dest))
6958 int xregno = REGNO (dest);
6959 int xnregs;
6960 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
6961 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
6962 else
6963 xnregs = 1;
6964 if (xregno < regno + nregs && xregno + xnregs > regno)
6965 return 0;
6966 if (xregno < valueno + valuenregs
6967 && xregno + xnregs > valueno)
6968 return 0;
6969 if (goal_mem_addr_varies
6970 && reg_overlap_mentioned_for_reload_p (dest, goal))
6971 return 0;
6972 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6973 return 0;
6975 else if (goal_mem && MEM_P (dest)
6976 && ! push_operand (dest, GET_MODE (dest)))
6977 return 0;
6978 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6979 && reg_equiv_memory_loc[regno] != 0)
6980 return 0;
6981 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6982 return 0;
6984 else if (GET_CODE (pat) == PARALLEL)
6986 int i;
6987 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6989 rtx v1 = XVECEXP (pat, 0, i);
6990 if (GET_CODE (v1) == COND_EXEC)
6991 v1 = COND_EXEC_CODE (v1);
6992 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6994 rtx dest = SET_DEST (v1);
6995 while (GET_CODE (dest) == SUBREG
6996 || GET_CODE (dest) == ZERO_EXTRACT
6997 || GET_CODE (dest) == STRICT_LOW_PART)
6998 dest = XEXP (dest, 0);
6999 if (REG_P (dest))
7001 int xregno = REGNO (dest);
7002 int xnregs;
7003 if (REGNO (dest) < FIRST_PSEUDO_REGISTER)
7004 xnregs = hard_regno_nregs[xregno][GET_MODE (dest)];
7005 else
7006 xnregs = 1;
7007 if (xregno < regno + nregs
7008 && xregno + xnregs > regno)
7009 return 0;
7010 if (xregno < valueno + valuenregs
7011 && xregno + xnregs > valueno)
7012 return 0;
7013 if (goal_mem_addr_varies
7014 && reg_overlap_mentioned_for_reload_p (dest,
7015 goal))
7016 return 0;
7017 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
7018 return 0;
7020 else if (goal_mem && MEM_P (dest)
7021 && ! push_operand (dest, GET_MODE (dest)))
7022 return 0;
7023 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
7024 && reg_equiv_memory_loc[regno] != 0)
7025 return 0;
7026 else if (need_stable_sp
7027 && push_operand (dest, GET_MODE (dest)))
7028 return 0;
7033 if (CALL_P (p) && CALL_INSN_FUNCTION_USAGE (p))
7035 rtx link;
7037 for (link = CALL_INSN_FUNCTION_USAGE (p); XEXP (link, 1) != 0;
7038 link = XEXP (link, 1))
7040 pat = XEXP (link, 0);
7041 if (GET_CODE (pat) == CLOBBER)
7043 rtx dest = SET_DEST (pat);
7045 if (REG_P (dest))
7047 int xregno = REGNO (dest);
7048 int xnregs
7049 = hard_regno_nregs[xregno][GET_MODE (dest)];
7051 if (xregno < regno + nregs
7052 && xregno + xnregs > regno)
7053 return 0;
7054 else if (xregno < valueno + valuenregs
7055 && xregno + xnregs > valueno)
7056 return 0;
7057 else if (goal_mem_addr_varies
7058 && reg_overlap_mentioned_for_reload_p (dest,
7059 goal))
7060 return 0;
7063 else if (goal_mem && MEM_P (dest)
7064 && ! push_operand (dest, GET_MODE (dest)))
7065 return 0;
7066 else if (need_stable_sp
7067 && push_operand (dest, GET_MODE (dest)))
7068 return 0;
7073 #ifdef AUTO_INC_DEC
7074 /* If this insn auto-increments or auto-decrements
7075 either regno or valueno, return 0 now.
7076 If GOAL is a memory ref and its address is not constant,
7077 and this insn P increments a register used in GOAL, return 0. */
7079 rtx link;
7081 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
7082 if (REG_NOTE_KIND (link) == REG_INC
7083 && REG_P (XEXP (link, 0)))
7085 int incno = REGNO (XEXP (link, 0));
7086 if (incno < regno + nregs && incno >= regno)
7087 return 0;
7088 if (incno < valueno + valuenregs && incno >= valueno)
7089 return 0;
7090 if (goal_mem_addr_varies
7091 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
7092 goal))
7093 return 0;
7096 #endif
7101 /* Find a place where INCED appears in an increment or decrement operator
7102 within X, and return the amount INCED is incremented or decremented by.
7103 The value is always positive. */
7105 static int
7106 find_inc_amount (rtx x, rtx inced)
7108 enum rtx_code code = GET_CODE (x);
7109 const char *fmt;
7110 int i;
7112 if (code == MEM)
7114 rtx addr = XEXP (x, 0);
7115 if ((GET_CODE (addr) == PRE_DEC
7116 || GET_CODE (addr) == POST_DEC
7117 || GET_CODE (addr) == PRE_INC
7118 || GET_CODE (addr) == POST_INC)
7119 && XEXP (addr, 0) == inced)
7120 return GET_MODE_SIZE (GET_MODE (x));
7121 else if ((GET_CODE (addr) == PRE_MODIFY
7122 || GET_CODE (addr) == POST_MODIFY)
7123 && GET_CODE (XEXP (addr, 1)) == PLUS
7124 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
7125 && XEXP (addr, 0) == inced
7126 && GET_CODE (XEXP (XEXP (addr, 1), 1)) == CONST_INT)
7128 i = INTVAL (XEXP (XEXP (addr, 1), 1));
7129 return i < 0 ? -i : i;
7133 fmt = GET_RTX_FORMAT (code);
7134 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7136 if (fmt[i] == 'e')
7138 int tem = find_inc_amount (XEXP (x, i), inced);
7139 if (tem != 0)
7140 return tem;
7142 if (fmt[i] == 'E')
7144 int j;
7145 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7147 int tem = find_inc_amount (XVECEXP (x, i, j), inced);
7148 if (tem != 0)
7149 return tem;
7154 return 0;
7157 /* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
7158 REG_INC note in insn INSN. REGNO must refer to a hard register. */
7160 #ifdef AUTO_INC_DEC
7161 static int
7162 reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
7163 rtx insn)
7165 rtx link;
7167 gcc_assert (insn);
7169 if (! INSN_P (insn))
7170 return 0;
7172 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
7173 if (REG_NOTE_KIND (link) == REG_INC)
7175 unsigned int test = (int) REGNO (XEXP (link, 0));
7176 if (test >= regno && test < endregno)
7177 return 1;
7179 return 0;
7181 #else
7183 #define reg_inc_found_and_valid_p(regno,endregno,insn) 0
7185 #endif
7187 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
7188 If SETS is 1, also consider SETs. If SETS is 2, enable checking
7189 REG_INC. REGNO must refer to a hard register. */
7192 regno_clobbered_p (unsigned int regno, rtx insn, enum machine_mode mode,
7193 int sets)
7195 unsigned int nregs, endregno;
7197 /* regno must be a hard register. */
7198 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
7200 nregs = hard_regno_nregs[regno][mode];
7201 endregno = regno + nregs;
7203 if ((GET_CODE (PATTERN (insn)) == CLOBBER
7204 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7205 && REG_P (XEXP (PATTERN (insn), 0)))
7207 unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
7209 return test >= regno && test < endregno;
7212 if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
7213 return 1;
7215 if (GET_CODE (PATTERN (insn)) == PARALLEL)
7217 int i = XVECLEN (PATTERN (insn), 0) - 1;
7219 for (; i >= 0; i--)
7221 rtx elt = XVECEXP (PATTERN (insn), 0, i);
7222 if ((GET_CODE (elt) == CLOBBER
7223 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7224 && REG_P (XEXP (elt, 0)))
7226 unsigned int test = REGNO (XEXP (elt, 0));
7228 if (test >= regno && test < endregno)
7229 return 1;
7231 if (sets == 2
7232 && reg_inc_found_and_valid_p (regno, endregno, elt))
7233 return 1;
7237 return 0;
7240 /* Find the low part, with mode MODE, of a hard regno RELOADREG. */
7242 reload_adjust_reg_for_mode (rtx reloadreg, enum machine_mode mode)
7244 int regno;
7246 if (GET_MODE (reloadreg) == mode)
7247 return reloadreg;
7249 regno = REGNO (reloadreg);
7251 if (WORDS_BIG_ENDIAN)
7252 regno += (int) hard_regno_nregs[regno][GET_MODE (reloadreg)]
7253 - (int) hard_regno_nregs[regno][mode];
7255 return gen_rtx_REG (mode, regno);
7258 static const char *const reload_when_needed_name[] =
7260 "RELOAD_FOR_INPUT",
7261 "RELOAD_FOR_OUTPUT",
7262 "RELOAD_FOR_INSN",
7263 "RELOAD_FOR_INPUT_ADDRESS",
7264 "RELOAD_FOR_INPADDR_ADDRESS",
7265 "RELOAD_FOR_OUTPUT_ADDRESS",
7266 "RELOAD_FOR_OUTADDR_ADDRESS",
7267 "RELOAD_FOR_OPERAND_ADDRESS",
7268 "RELOAD_FOR_OPADDR_ADDR",
7269 "RELOAD_OTHER",
7270 "RELOAD_FOR_OTHER_ADDRESS"
7273 /* These functions are used to print the variables set by 'find_reloads' */
7275 void
7276 debug_reload_to_stream (FILE *f)
7278 int r;
7279 const char *prefix;
7281 if (! f)
7282 f = stderr;
7283 for (r = 0; r < n_reloads; r++)
7285 fprintf (f, "Reload %d: ", r);
7287 if (rld[r].in != 0)
7289 fprintf (f, "reload_in (%s) = ",
7290 GET_MODE_NAME (rld[r].inmode));
7291 print_inline_rtx (f, rld[r].in, 24);
7292 fprintf (f, "\n\t");
7295 if (rld[r].out != 0)
7297 fprintf (f, "reload_out (%s) = ",
7298 GET_MODE_NAME (rld[r].outmode));
7299 print_inline_rtx (f, rld[r].out, 24);
7300 fprintf (f, "\n\t");
7303 fprintf (f, "%s, ", reg_class_names[(int) rld[r].rclass]);
7305 fprintf (f, "%s (opnum = %d)",
7306 reload_when_needed_name[(int) rld[r].when_needed],
7307 rld[r].opnum);
7309 if (rld[r].optional)
7310 fprintf (f, ", optional");
7312 if (rld[r].nongroup)
7313 fprintf (f, ", nongroup");
7315 if (rld[r].inc != 0)
7316 fprintf (f, ", inc by %d", rld[r].inc);
7318 if (rld[r].nocombine)
7319 fprintf (f, ", can't combine");
7321 if (rld[r].secondary_p)
7322 fprintf (f, ", secondary_reload_p");
7324 if (rld[r].in_reg != 0)
7326 fprintf (f, "\n\treload_in_reg: ");
7327 print_inline_rtx (f, rld[r].in_reg, 24);
7330 if (rld[r].out_reg != 0)
7332 fprintf (f, "\n\treload_out_reg: ");
7333 print_inline_rtx (f, rld[r].out_reg, 24);
7336 if (rld[r].reg_rtx != 0)
7338 fprintf (f, "\n\treload_reg_rtx: ");
7339 print_inline_rtx (f, rld[r].reg_rtx, 24);
7342 prefix = "\n\t";
7343 if (rld[r].secondary_in_reload != -1)
7345 fprintf (f, "%ssecondary_in_reload = %d",
7346 prefix, rld[r].secondary_in_reload);
7347 prefix = ", ";
7350 if (rld[r].secondary_out_reload != -1)
7351 fprintf (f, "%ssecondary_out_reload = %d\n",
7352 prefix, rld[r].secondary_out_reload);
7354 prefix = "\n\t";
7355 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
7357 fprintf (f, "%ssecondary_in_icode = %s", prefix,
7358 insn_data[rld[r].secondary_in_icode].name);
7359 prefix = ", ";
7362 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
7363 fprintf (f, "%ssecondary_out_icode = %s", prefix,
7364 insn_data[rld[r].secondary_out_icode].name);
7366 fprintf (f, "\n");
7370 void
7371 debug_reload (void)
7373 debug_reload_to_stream (stderr);