[rs6000] Use gen_int_mode in ieee_128bit_negative_zero
[official-gcc.git] / gcc / reload.c
blob0d986f73b346e7574d9c67e4eb5471014f8c711b
1 /* Search an insn for pseudo regs that must be in hard regs and are not.
2 Copyright (C) 1987-2017 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This file contains subroutines used only from the file reload1.c.
21 It knows how to scan one insn for operands and values
22 that need to be copied into registers to make valid code.
23 It also finds other operands and values which are valid
24 but for which equivalent values in registers exist and
25 ought to be used instead.
27 Before processing the first insn of the function, call `init_reload'.
28 init_reload actually has to be called earlier anyway.
30 To scan an insn, call `find_reloads'. This does two things:
31 1. sets up tables describing which values must be reloaded
32 for this insn, and what kind of hard regs they must be reloaded into;
33 2. optionally record the locations where those values appear in
34 the data, so they can be replaced properly later.
35 This is done only if the second arg to `find_reloads' is nonzero.
37 The third arg to `find_reloads' specifies the number of levels
38 of indirect addressing supported by the machine. If it is zero,
39 indirect addressing is not valid. If it is one, (MEM (REG n))
40 is valid even if (REG n) did not get a hard register; if it is two,
41 (MEM (MEM (REG n))) is also valid even if (REG n) did not get a
42 hard register, and similarly for higher values.
44 Then you must choose the hard regs to reload those pseudo regs into,
45 and generate appropriate load insns before this insn and perhaps
46 also store insns after this insn. Set up the array `reload_reg_rtx'
47 to contain the REG rtx's for the registers you used. In some
48 cases `find_reloads' will return a nonzero value in `reload_reg_rtx'
49 for certain reloads. Then that tells you which register to use,
50 so you do not need to allocate one. But you still do need to add extra
51 instructions to copy the value into and out of that register.
53 Finally you must call `subst_reloads' to substitute the reload reg rtx's
54 into the locations already recorded.
56 NOTE SIDE EFFECTS:
58 find_reloads can alter the operands of the instruction it is called on.
60 1. Two operands of any sort may be interchanged, if they are in a
61 commutative instruction.
62 This happens only if find_reloads thinks the instruction will compile
63 better that way.
65 2. Pseudo-registers that are equivalent to constants are replaced
66 with those constants if they are not in hard registers.
68 1 happens every time find_reloads is called.
69 2 happens only when REPLACE is 1, which is only when
70 actually doing the reloads, not when just counting them.
72 Using a reload register for several reloads in one insn:
74 When an insn has reloads, it is considered as having three parts:
75 the input reloads, the insn itself after reloading, and the output reloads.
76 Reloads of values used in memory addresses are often needed for only one part.
78 When this is so, reload_when_needed records which part needs the reload.
79 Two reloads for different parts of the insn can share the same reload
80 register.
82 When a reload is used for addresses in multiple parts, or when it is
83 an ordinary operand, it is classified as RELOAD_OTHER, and cannot share
84 a register with any other reload. */
86 #define REG_OK_STRICT
88 /* We do not enable this with CHECKING_P, since it is awfully slow. */
89 #undef DEBUG_RELOAD
91 #include "config.h"
92 #include "system.h"
93 #include "coretypes.h"
94 #include "backend.h"
95 #include "target.h"
96 #include "rtl.h"
97 #include "tree.h"
98 #include "df.h"
99 #include "memmodel.h"
100 #include "tm_p.h"
101 #include "optabs.h"
102 #include "regs.h"
103 #include "ira.h"
104 #include "recog.h"
105 #include "rtl-error.h"
106 #include "reload.h"
107 #include "addresses.h"
108 #include "params.h"
110 /* True if X is a constant that can be forced into the constant pool.
111 MODE is the mode of the operand, or VOIDmode if not known. */
112 #define CONST_POOL_OK_P(MODE, X) \
113 ((MODE) != VOIDmode \
114 && CONSTANT_P (X) \
115 && GET_CODE (X) != HIGH \
116 && !targetm.cannot_force_const_mem (MODE, X))
118 /* True if C is a non-empty register class that has too few registers
119 to be safely used as a reload target class. */
121 static inline bool
122 small_register_class_p (reg_class_t rclass)
124 return (reg_class_size [(int) rclass] == 1
125 || (reg_class_size [(int) rclass] >= 1
126 && targetm.class_likely_spilled_p (rclass)));
130 /* All reloads of the current insn are recorded here. See reload.h for
131 comments. */
132 int n_reloads;
133 struct reload rld[MAX_RELOADS];
135 /* All the "earlyclobber" operands of the current insn
136 are recorded here. */
137 int n_earlyclobbers;
138 rtx reload_earlyclobbers[MAX_RECOG_OPERANDS];
140 int reload_n_operands;
142 /* Replacing reloads.
144 If `replace_reloads' is nonzero, then as each reload is recorded
145 an entry is made for it in the table `replacements'.
146 Then later `subst_reloads' can look through that table and
147 perform all the replacements needed. */
149 /* Nonzero means record the places to replace. */
150 static int replace_reloads;
152 /* Each replacement is recorded with a structure like this. */
153 struct replacement
155 rtx *where; /* Location to store in */
156 int what; /* which reload this is for */
157 machine_mode mode; /* mode it must have */
160 static struct replacement replacements[MAX_RECOG_OPERANDS * ((MAX_REGS_PER_ADDRESS * 2) + 1)];
162 /* Number of replacements currently recorded. */
163 static int n_replacements;
165 /* Used to track what is modified by an operand. */
166 struct decomposition
168 int reg_flag; /* Nonzero if referencing a register. */
169 int safe; /* Nonzero if this can't conflict with anything. */
170 rtx base; /* Base address for MEM. */
171 poly_int64_pod start; /* Starting offset or register number. */
172 poly_int64_pod end; /* Ending offset or register number. */
175 /* Save MEMs needed to copy from one class of registers to another. One MEM
176 is used per mode, but normally only one or two modes are ever used.
178 We keep two versions, before and after register elimination. The one
179 after register elimination is record separately for each operand. This
180 is done in case the address is not valid to be sure that we separately
181 reload each. */
183 static rtx secondary_memlocs[NUM_MACHINE_MODES];
184 static rtx secondary_memlocs_elim[NUM_MACHINE_MODES][MAX_RECOG_OPERANDS];
185 static int secondary_memlocs_elim_used = 0;
187 /* The instruction we are doing reloads for;
188 so we can test whether a register dies in it. */
189 static rtx_insn *this_insn;
191 /* Nonzero if this instruction is a user-specified asm with operands. */
192 static int this_insn_is_asm;
194 /* If hard_regs_live_known is nonzero,
195 we can tell which hard regs are currently live,
196 at least enough to succeed in choosing dummy reloads. */
197 static int hard_regs_live_known;
199 /* Indexed by hard reg number,
200 element is nonnegative if hard reg has been spilled.
201 This vector is passed to `find_reloads' as an argument
202 and is not changed here. */
203 static short *static_reload_reg_p;
205 /* Set to 1 in subst_reg_equivs if it changes anything. */
206 static int subst_reg_equivs_changed;
208 /* On return from push_reload, holds the reload-number for the OUT
209 operand, which can be different for that from the input operand. */
210 static int output_reloadnum;
212 /* Compare two RTX's. */
213 #define MATCHES(x, y) \
214 (x == y || (x != 0 && (REG_P (x) \
215 ? REG_P (y) && REGNO (x) == REGNO (y) \
216 : rtx_equal_p (x, y) && ! side_effects_p (x))))
218 /* Indicates if two reloads purposes are for similar enough things that we
219 can merge their reloads. */
220 #define MERGABLE_RELOADS(when1, when2, op1, op2) \
221 ((when1) == RELOAD_OTHER || (when2) == RELOAD_OTHER \
222 || ((when1) == (when2) && (op1) == (op2)) \
223 || ((when1) == RELOAD_FOR_INPUT && (when2) == RELOAD_FOR_INPUT) \
224 || ((when1) == RELOAD_FOR_OPERAND_ADDRESS \
225 && (when2) == RELOAD_FOR_OPERAND_ADDRESS) \
226 || ((when1) == RELOAD_FOR_OTHER_ADDRESS \
227 && (when2) == RELOAD_FOR_OTHER_ADDRESS))
229 /* Nonzero if these two reload purposes produce RELOAD_OTHER when merged. */
230 #define MERGE_TO_OTHER(when1, when2, op1, op2) \
231 ((when1) != (when2) \
232 || ! ((op1) == (op2) \
233 || (when1) == RELOAD_FOR_INPUT \
234 || (when1) == RELOAD_FOR_OPERAND_ADDRESS \
235 || (when1) == RELOAD_FOR_OTHER_ADDRESS))
237 /* If we are going to reload an address, compute the reload type to
238 use. */
239 #define ADDR_TYPE(type) \
240 ((type) == RELOAD_FOR_INPUT_ADDRESS \
241 ? RELOAD_FOR_INPADDR_ADDRESS \
242 : ((type) == RELOAD_FOR_OUTPUT_ADDRESS \
243 ? RELOAD_FOR_OUTADDR_ADDRESS \
244 : (type)))
246 static int push_secondary_reload (int, rtx, int, int, enum reg_class,
247 machine_mode, enum reload_type,
248 enum insn_code *, secondary_reload_info *);
249 static enum reg_class find_valid_class (machine_mode, machine_mode,
250 int, unsigned int);
251 static void push_replacement (rtx *, int, machine_mode);
252 static void dup_replacements (rtx *, rtx *);
253 static void combine_reloads (void);
254 static int find_reusable_reload (rtx *, rtx, enum reg_class,
255 enum reload_type, int, int);
256 static rtx find_dummy_reload (rtx, rtx, rtx *, rtx *, machine_mode,
257 machine_mode, reg_class_t, int, int);
258 static int hard_reg_set_here_p (unsigned int, unsigned int, rtx);
259 static struct decomposition decompose (rtx);
260 static int immune_p (rtx, rtx, struct decomposition);
261 static bool alternative_allows_const_pool_ref (rtx, const char *, int);
262 static rtx find_reloads_toplev (rtx, int, enum reload_type, int, int,
263 rtx_insn *, int *);
264 static rtx make_memloc (rtx, int);
265 static int maybe_memory_address_addr_space_p (machine_mode, rtx,
266 addr_space_t, rtx *);
267 static int find_reloads_address (machine_mode, rtx *, rtx, rtx *,
268 int, enum reload_type, int, rtx_insn *);
269 static rtx subst_reg_equivs (rtx, rtx_insn *);
270 static rtx subst_indexed_address (rtx);
271 static void update_auto_inc_notes (rtx_insn *, int, int);
272 static int find_reloads_address_1 (machine_mode, addr_space_t, rtx, int,
273 enum rtx_code, enum rtx_code, rtx *,
274 int, enum reload_type,int, rtx_insn *);
275 static void find_reloads_address_part (rtx, rtx *, enum reg_class,
276 machine_mode, int,
277 enum reload_type, int);
278 static rtx find_reloads_subreg_address (rtx, int, enum reload_type,
279 int, rtx_insn *, int *);
280 static void copy_replacements_1 (rtx *, rtx *, int);
281 static poly_int64 find_inc_amount (rtx, rtx);
282 static int refers_to_mem_for_reload_p (rtx);
283 static int refers_to_regno_for_reload_p (unsigned int, unsigned int,
284 rtx, rtx *);
286 /* Add NEW to reg_equiv_alt_mem_list[REGNO] if it's not present in the
287 list yet. */
289 static void
290 push_reg_equiv_alt_mem (int regno, rtx mem)
292 rtx it;
294 for (it = reg_equiv_alt_mem_list (regno); it; it = XEXP (it, 1))
295 if (rtx_equal_p (XEXP (it, 0), mem))
296 return;
298 reg_equiv_alt_mem_list (regno)
299 = alloc_EXPR_LIST (REG_EQUIV, mem,
300 reg_equiv_alt_mem_list (regno));
303 /* Determine if any secondary reloads are needed for loading (if IN_P is
304 nonzero) or storing (if IN_P is zero) X to or from a reload register of
305 register class RELOAD_CLASS in mode RELOAD_MODE. If secondary reloads
306 are needed, push them.
308 Return the reload number of the secondary reload we made, or -1 if
309 we didn't need one. *PICODE is set to the insn_code to use if we do
310 need a secondary reload. */
312 static int
313 push_secondary_reload (int in_p, rtx x, int opnum, int optional,
314 enum reg_class reload_class,
315 machine_mode reload_mode, enum reload_type type,
316 enum insn_code *picode, secondary_reload_info *prev_sri)
318 enum reg_class rclass = NO_REGS;
319 enum reg_class scratch_class;
320 machine_mode mode = reload_mode;
321 enum insn_code icode = CODE_FOR_nothing;
322 enum insn_code t_icode = CODE_FOR_nothing;
323 enum reload_type secondary_type;
324 int s_reload, t_reload = -1;
325 const char *scratch_constraint;
326 secondary_reload_info sri;
328 if (type == RELOAD_FOR_INPUT_ADDRESS
329 || type == RELOAD_FOR_OUTPUT_ADDRESS
330 || type == RELOAD_FOR_INPADDR_ADDRESS
331 || type == RELOAD_FOR_OUTADDR_ADDRESS)
332 secondary_type = type;
333 else
334 secondary_type = in_p ? RELOAD_FOR_INPUT_ADDRESS : RELOAD_FOR_OUTPUT_ADDRESS;
336 *picode = CODE_FOR_nothing;
338 /* If X is a paradoxical SUBREG, use the inner value to determine both the
339 mode and object being reloaded. */
340 if (paradoxical_subreg_p (x))
342 x = SUBREG_REG (x);
343 reload_mode = GET_MODE (x);
346 /* If X is a pseudo-register that has an equivalent MEM (actually, if it
347 is still a pseudo-register by now, it *must* have an equivalent MEM
348 but we don't want to assume that), use that equivalent when seeing if
349 a secondary reload is needed since whether or not a reload is needed
350 might be sensitive to the form of the MEM. */
352 if (REG_P (x) && REGNO (x) >= FIRST_PSEUDO_REGISTER
353 && reg_equiv_mem (REGNO (x)))
354 x = reg_equiv_mem (REGNO (x));
356 sri.icode = CODE_FOR_nothing;
357 sri.prev_sri = prev_sri;
358 rclass = (enum reg_class) targetm.secondary_reload (in_p, x, reload_class,
359 reload_mode, &sri);
360 icode = (enum insn_code) sri.icode;
362 /* If we don't need any secondary registers, done. */
363 if (rclass == NO_REGS && icode == CODE_FOR_nothing)
364 return -1;
366 if (rclass != NO_REGS)
367 t_reload = push_secondary_reload (in_p, x, opnum, optional, rclass,
368 reload_mode, type, &t_icode, &sri);
370 /* If we will be using an insn, the secondary reload is for a
371 scratch register. */
373 if (icode != CODE_FOR_nothing)
375 /* If IN_P is nonzero, the reload register will be the output in
376 operand 0. If IN_P is zero, the reload register will be the input
377 in operand 1. Outputs should have an initial "=", which we must
378 skip. */
380 /* ??? It would be useful to be able to handle only two, or more than
381 three, operands, but for now we can only handle the case of having
382 exactly three: output, input and one temp/scratch. */
383 gcc_assert (insn_data[(int) icode].n_operands == 3);
385 /* ??? We currently have no way to represent a reload that needs
386 an icode to reload from an intermediate tertiary reload register.
387 We should probably have a new field in struct reload to tag a
388 chain of scratch operand reloads onto. */
389 gcc_assert (rclass == NO_REGS);
391 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
392 gcc_assert (*scratch_constraint == '=');
393 scratch_constraint++;
394 if (*scratch_constraint == '&')
395 scratch_constraint++;
396 scratch_class = (reg_class_for_constraint
397 (lookup_constraint (scratch_constraint)));
399 rclass = scratch_class;
400 mode = insn_data[(int) icode].operand[2].mode;
403 /* This case isn't valid, so fail. Reload is allowed to use the same
404 register for RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT reloads, but
405 in the case of a secondary register, we actually need two different
406 registers for correct code. We fail here to prevent the possibility of
407 silently generating incorrect code later.
409 The convention is that secondary input reloads are valid only if the
410 secondary_class is different from class. If you have such a case, you
411 can not use secondary reloads, you must work around the problem some
412 other way.
414 Allow this when a reload_in/out pattern is being used. I.e. assume
415 that the generated code handles this case. */
417 gcc_assert (!in_p || rclass != reload_class || icode != CODE_FOR_nothing
418 || t_icode != CODE_FOR_nothing);
420 /* See if we can reuse an existing secondary reload. */
421 for (s_reload = 0; s_reload < n_reloads; s_reload++)
422 if (rld[s_reload].secondary_p
423 && (reg_class_subset_p (rclass, rld[s_reload].rclass)
424 || reg_class_subset_p (rld[s_reload].rclass, rclass))
425 && ((in_p && rld[s_reload].inmode == mode)
426 || (! in_p && rld[s_reload].outmode == mode))
427 && ((in_p && rld[s_reload].secondary_in_reload == t_reload)
428 || (! in_p && rld[s_reload].secondary_out_reload == t_reload))
429 && ((in_p && rld[s_reload].secondary_in_icode == t_icode)
430 || (! in_p && rld[s_reload].secondary_out_icode == t_icode))
431 && (small_register_class_p (rclass)
432 || targetm.small_register_classes_for_mode_p (VOIDmode))
433 && MERGABLE_RELOADS (secondary_type, rld[s_reload].when_needed,
434 opnum, rld[s_reload].opnum))
436 if (in_p)
437 rld[s_reload].inmode = mode;
438 if (! in_p)
439 rld[s_reload].outmode = mode;
441 if (reg_class_subset_p (rclass, rld[s_reload].rclass))
442 rld[s_reload].rclass = rclass;
444 rld[s_reload].opnum = MIN (rld[s_reload].opnum, opnum);
445 rld[s_reload].optional &= optional;
446 rld[s_reload].secondary_p = 1;
447 if (MERGE_TO_OTHER (secondary_type, rld[s_reload].when_needed,
448 opnum, rld[s_reload].opnum))
449 rld[s_reload].when_needed = RELOAD_OTHER;
451 break;
454 if (s_reload == n_reloads)
456 /* If we need a memory location to copy between the two reload regs,
457 set it up now. Note that we do the input case before making
458 the reload and the output case after. This is due to the
459 way reloads are output. */
461 if (in_p && icode == CODE_FOR_nothing
462 && targetm.secondary_memory_needed (mode, rclass, reload_class))
464 get_secondary_mem (x, reload_mode, opnum, type);
466 /* We may have just added new reloads. Make sure we add
467 the new reload at the end. */
468 s_reload = n_reloads;
471 /* We need to make a new secondary reload for this register class. */
472 rld[s_reload].in = rld[s_reload].out = 0;
473 rld[s_reload].rclass = rclass;
475 rld[s_reload].inmode = in_p ? mode : VOIDmode;
476 rld[s_reload].outmode = ! in_p ? mode : VOIDmode;
477 rld[s_reload].reg_rtx = 0;
478 rld[s_reload].optional = optional;
479 rld[s_reload].inc = 0;
480 /* Maybe we could combine these, but it seems too tricky. */
481 rld[s_reload].nocombine = 1;
482 rld[s_reload].in_reg = 0;
483 rld[s_reload].out_reg = 0;
484 rld[s_reload].opnum = opnum;
485 rld[s_reload].when_needed = secondary_type;
486 rld[s_reload].secondary_in_reload = in_p ? t_reload : -1;
487 rld[s_reload].secondary_out_reload = ! in_p ? t_reload : -1;
488 rld[s_reload].secondary_in_icode = in_p ? t_icode : CODE_FOR_nothing;
489 rld[s_reload].secondary_out_icode
490 = ! in_p ? t_icode : CODE_FOR_nothing;
491 rld[s_reload].secondary_p = 1;
493 n_reloads++;
495 if (! in_p && icode == CODE_FOR_nothing
496 && targetm.secondary_memory_needed (mode, reload_class, rclass))
497 get_secondary_mem (x, mode, opnum, type);
500 *picode = icode;
501 return s_reload;
504 /* If a secondary reload is needed, return its class. If both an intermediate
505 register and a scratch register is needed, we return the class of the
506 intermediate register. */
507 reg_class_t
508 secondary_reload_class (bool in_p, reg_class_t rclass, machine_mode mode,
509 rtx x)
511 enum insn_code icode;
512 secondary_reload_info sri;
514 sri.icode = CODE_FOR_nothing;
515 sri.prev_sri = NULL;
516 rclass
517 = (enum reg_class) targetm.secondary_reload (in_p, x, rclass, mode, &sri);
518 icode = (enum insn_code) sri.icode;
520 /* If there are no secondary reloads at all, we return NO_REGS.
521 If an intermediate register is needed, we return its class. */
522 if (icode == CODE_FOR_nothing || rclass != NO_REGS)
523 return rclass;
525 /* No intermediate register is needed, but we have a special reload
526 pattern, which we assume for now needs a scratch register. */
527 return scratch_reload_class (icode);
530 /* ICODE is the insn_code of a reload pattern. Check that it has exactly
531 three operands, verify that operand 2 is an output operand, and return
532 its register class.
533 ??? We'd like to be able to handle any pattern with at least 2 operands,
534 for zero or more scratch registers, but that needs more infrastructure. */
535 enum reg_class
536 scratch_reload_class (enum insn_code icode)
538 const char *scratch_constraint;
539 enum reg_class rclass;
541 gcc_assert (insn_data[(int) icode].n_operands == 3);
542 scratch_constraint = insn_data[(int) icode].operand[2].constraint;
543 gcc_assert (*scratch_constraint == '=');
544 scratch_constraint++;
545 if (*scratch_constraint == '&')
546 scratch_constraint++;
547 rclass = reg_class_for_constraint (lookup_constraint (scratch_constraint));
548 gcc_assert (rclass != NO_REGS);
549 return rclass;
552 /* Return a memory location that will be used to copy X in mode MODE.
553 If we haven't already made a location for this mode in this insn,
554 call find_reloads_address on the location being returned. */
557 get_secondary_mem (rtx x ATTRIBUTE_UNUSED, machine_mode mode,
558 int opnum, enum reload_type type)
560 rtx loc;
561 int mem_valid;
563 /* By default, if MODE is narrower than a word, widen it to a word.
564 This is required because most machines that require these memory
565 locations do not support short load and stores from all registers
566 (e.g., FP registers). */
568 mode = targetm.secondary_memory_needed_mode (mode);
570 /* If we already have made a MEM for this operand in MODE, return it. */
571 if (secondary_memlocs_elim[(int) mode][opnum] != 0)
572 return secondary_memlocs_elim[(int) mode][opnum];
574 /* If this is the first time we've tried to get a MEM for this mode,
575 allocate a new one. `something_changed' in reload will get set
576 by noticing that the frame size has changed. */
578 if (secondary_memlocs[(int) mode] == 0)
580 #ifdef SECONDARY_MEMORY_NEEDED_RTX
581 secondary_memlocs[(int) mode] = SECONDARY_MEMORY_NEEDED_RTX (mode);
582 #else
583 secondary_memlocs[(int) mode]
584 = assign_stack_local (mode, GET_MODE_SIZE (mode), 0);
585 #endif
588 /* Get a version of the address doing any eliminations needed. If that
589 didn't give us a new MEM, make a new one if it isn't valid. */
591 loc = eliminate_regs (secondary_memlocs[(int) mode], VOIDmode, NULL_RTX);
592 mem_valid = strict_memory_address_addr_space_p (mode, XEXP (loc, 0),
593 MEM_ADDR_SPACE (loc));
595 if (! mem_valid && loc == secondary_memlocs[(int) mode])
596 loc = copy_rtx (loc);
598 /* The only time the call below will do anything is if the stack
599 offset is too large. In that case IND_LEVELS doesn't matter, so we
600 can just pass a zero. Adjust the type to be the address of the
601 corresponding object. If the address was valid, save the eliminated
602 address. If it wasn't valid, we need to make a reload each time, so
603 don't save it. */
605 if (! mem_valid)
607 type = (type == RELOAD_FOR_INPUT ? RELOAD_FOR_INPUT_ADDRESS
608 : type == RELOAD_FOR_OUTPUT ? RELOAD_FOR_OUTPUT_ADDRESS
609 : RELOAD_OTHER);
611 find_reloads_address (mode, &loc, XEXP (loc, 0), &XEXP (loc, 0),
612 opnum, type, 0, 0);
615 secondary_memlocs_elim[(int) mode][opnum] = loc;
616 if (secondary_memlocs_elim_used <= (int)mode)
617 secondary_memlocs_elim_used = (int)mode + 1;
618 return loc;
621 /* Clear any secondary memory locations we've made. */
623 void
624 clear_secondary_mem (void)
626 memset (secondary_memlocs, 0, sizeof secondary_memlocs);
630 /* Find the largest class which has at least one register valid in
631 mode INNER, and which for every such register, that register number
632 plus N is also valid in OUTER (if in range) and is cheap to move
633 into REGNO. Such a class must exist. */
635 static enum reg_class
636 find_valid_class (machine_mode outer ATTRIBUTE_UNUSED,
637 machine_mode inner ATTRIBUTE_UNUSED, int n,
638 unsigned int dest_regno ATTRIBUTE_UNUSED)
640 int best_cost = -1;
641 int rclass;
642 int regno;
643 enum reg_class best_class = NO_REGS;
644 enum reg_class dest_class ATTRIBUTE_UNUSED = REGNO_REG_CLASS (dest_regno);
645 unsigned int best_size = 0;
646 int cost;
648 for (rclass = 1; rclass < N_REG_CLASSES; rclass++)
650 int bad = 0;
651 int good = 0;
652 for (regno = 0; regno < FIRST_PSEUDO_REGISTER - n && ! bad; regno++)
653 if (TEST_HARD_REG_BIT (reg_class_contents[rclass], regno))
655 if (targetm.hard_regno_mode_ok (regno, inner))
657 good = 1;
658 if (TEST_HARD_REG_BIT (reg_class_contents[rclass], regno + n)
659 && !targetm.hard_regno_mode_ok (regno + n, outer))
660 bad = 1;
664 if (bad || !good)
665 continue;
666 cost = register_move_cost (outer, (enum reg_class) rclass, dest_class);
668 if ((reg_class_size[rclass] > best_size
669 && (best_cost < 0 || best_cost >= cost))
670 || best_cost > cost)
672 best_class = (enum reg_class) rclass;
673 best_size = reg_class_size[rclass];
674 best_cost = register_move_cost (outer, (enum reg_class) rclass,
675 dest_class);
679 gcc_assert (best_size != 0);
681 return best_class;
684 /* We are trying to reload a subreg of something that is not a register.
685 Find the largest class which contains only registers valid in
686 mode MODE. OUTER is the mode of the subreg, DEST_CLASS the class in
687 which we would eventually like to obtain the object. */
689 static enum reg_class
690 find_valid_class_1 (machine_mode outer ATTRIBUTE_UNUSED,
691 machine_mode mode ATTRIBUTE_UNUSED,
692 enum reg_class dest_class ATTRIBUTE_UNUSED)
694 int best_cost = -1;
695 int rclass;
696 int regno;
697 enum reg_class best_class = NO_REGS;
698 unsigned int best_size = 0;
699 int cost;
701 for (rclass = 1; rclass < N_REG_CLASSES; rclass++)
703 unsigned int computed_rclass_size = 0;
705 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
707 if (in_hard_reg_set_p (reg_class_contents[rclass], mode, regno)
708 && targetm.hard_regno_mode_ok (regno, mode))
709 computed_rclass_size++;
712 cost = register_move_cost (outer, (enum reg_class) rclass, dest_class);
714 if ((computed_rclass_size > best_size
715 && (best_cost < 0 || best_cost >= cost))
716 || best_cost > cost)
718 best_class = (enum reg_class) rclass;
719 best_size = computed_rclass_size;
720 best_cost = register_move_cost (outer, (enum reg_class) rclass,
721 dest_class);
725 gcc_assert (best_size != 0);
727 #ifdef LIMIT_RELOAD_CLASS
728 best_class = LIMIT_RELOAD_CLASS (mode, best_class);
729 #endif
730 return best_class;
733 /* Return the number of a previously made reload that can be combined with
734 a new one, or n_reloads if none of the existing reloads can be used.
735 OUT, RCLASS, TYPE and OPNUM are the same arguments as passed to
736 push_reload, they determine the kind of the new reload that we try to
737 combine. P_IN points to the corresponding value of IN, which can be
738 modified by this function.
739 DONT_SHARE is nonzero if we can't share any input-only reload for IN. */
741 static int
742 find_reusable_reload (rtx *p_in, rtx out, enum reg_class rclass,
743 enum reload_type type, int opnum, int dont_share)
745 rtx in = *p_in;
746 int i;
747 /* We can't merge two reloads if the output of either one is
748 earlyclobbered. */
750 if (earlyclobber_operand_p (out))
751 return n_reloads;
753 /* We can use an existing reload if the class is right
754 and at least one of IN and OUT is a match
755 and the other is at worst neutral.
756 (A zero compared against anything is neutral.)
758 For targets with small register classes, don't use existing reloads
759 unless they are for the same thing since that can cause us to need
760 more reload registers than we otherwise would. */
762 for (i = 0; i < n_reloads; i++)
763 if ((reg_class_subset_p (rclass, rld[i].rclass)
764 || reg_class_subset_p (rld[i].rclass, rclass))
765 /* If the existing reload has a register, it must fit our class. */
766 && (rld[i].reg_rtx == 0
767 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
768 true_regnum (rld[i].reg_rtx)))
769 && ((in != 0 && MATCHES (rld[i].in, in) && ! dont_share
770 && (out == 0 || rld[i].out == 0 || MATCHES (rld[i].out, out)))
771 || (out != 0 && MATCHES (rld[i].out, out)
772 && (in == 0 || rld[i].in == 0 || MATCHES (rld[i].in, in))))
773 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
774 && (small_register_class_p (rclass)
775 || targetm.small_register_classes_for_mode_p (VOIDmode))
776 && MERGABLE_RELOADS (type, rld[i].when_needed, opnum, rld[i].opnum))
777 return i;
779 /* Reloading a plain reg for input can match a reload to postincrement
780 that reg, since the postincrement's value is the right value.
781 Likewise, it can match a preincrement reload, since we regard
782 the preincrementation as happening before any ref in this insn
783 to that register. */
784 for (i = 0; i < n_reloads; i++)
785 if ((reg_class_subset_p (rclass, rld[i].rclass)
786 || reg_class_subset_p (rld[i].rclass, rclass))
787 /* If the existing reload has a register, it must fit our
788 class. */
789 && (rld[i].reg_rtx == 0
790 || TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
791 true_regnum (rld[i].reg_rtx)))
792 && out == 0 && rld[i].out == 0 && rld[i].in != 0
793 && ((REG_P (in)
794 && GET_RTX_CLASS (GET_CODE (rld[i].in)) == RTX_AUTOINC
795 && MATCHES (XEXP (rld[i].in, 0), in))
796 || (REG_P (rld[i].in)
797 && GET_RTX_CLASS (GET_CODE (in)) == RTX_AUTOINC
798 && MATCHES (XEXP (in, 0), rld[i].in)))
799 && (rld[i].out == 0 || ! earlyclobber_operand_p (rld[i].out))
800 && (small_register_class_p (rclass)
801 || targetm.small_register_classes_for_mode_p (VOIDmode))
802 && MERGABLE_RELOADS (type, rld[i].when_needed,
803 opnum, rld[i].opnum))
805 /* Make sure reload_in ultimately has the increment,
806 not the plain register. */
807 if (REG_P (in))
808 *p_in = rld[i].in;
809 return i;
811 return n_reloads;
814 /* Return true if X is a SUBREG that will need reloading of its SUBREG_REG
815 expression. MODE is the mode that X will be used in. OUTPUT is true if
816 the function is invoked for the output part of an enclosing reload. */
818 static bool
819 reload_inner_reg_of_subreg (rtx x, machine_mode mode, bool output)
821 rtx inner;
823 /* Only SUBREGs are problematical. */
824 if (GET_CODE (x) != SUBREG)
825 return false;
827 inner = SUBREG_REG (x);
829 /* If INNER is a constant or PLUS, then INNER will need reloading. */
830 if (CONSTANT_P (inner) || GET_CODE (inner) == PLUS)
831 return true;
833 /* If INNER is not a hard register, then INNER will not need reloading. */
834 if (!(REG_P (inner) && HARD_REGISTER_P (inner)))
835 return false;
837 /* If INNER is not ok for MODE, then INNER will need reloading. */
838 if (!targetm.hard_regno_mode_ok (subreg_regno (x), mode))
839 return true;
841 /* If this is for an output, and the outer part is a word or smaller,
842 INNER is larger than a word and the number of registers in INNER is
843 not the same as the number of words in INNER, then INNER will need
844 reloading (with an in-out reload). */
845 return (output
846 && GET_MODE_SIZE (mode) <= UNITS_PER_WORD
847 && GET_MODE_SIZE (GET_MODE (inner)) > UNITS_PER_WORD
848 && ((GET_MODE_SIZE (GET_MODE (inner)) / UNITS_PER_WORD)
849 != REG_NREGS (inner)));
852 /* Return nonzero if IN can be reloaded into REGNO with mode MODE without
853 requiring an extra reload register. The caller has already found that
854 IN contains some reference to REGNO, so check that we can produce the
855 new value in a single step. E.g. if we have
856 (set (reg r13) (plus (reg r13) (const int 1))), and there is an
857 instruction that adds one to a register, this should succeed.
858 However, if we have something like
859 (set (reg r13) (plus (reg r13) (const int 999))), and the constant 999
860 needs to be loaded into a register first, we need a separate reload
861 register.
862 Such PLUS reloads are generated by find_reload_address_part.
863 The out-of-range PLUS expressions are usually introduced in the instruction
864 patterns by register elimination and substituting pseudos without a home
865 by their function-invariant equivalences. */
866 static int
867 can_reload_into (rtx in, int regno, machine_mode mode)
869 rtx dst;
870 rtx_insn *test_insn;
871 int r = 0;
872 struct recog_data_d save_recog_data;
874 /* For matching constraints, we often get notional input reloads where
875 we want to use the original register as the reload register. I.e.
876 technically this is a non-optional input-output reload, but IN is
877 already a valid register, and has been chosen as the reload register.
878 Speed this up, since it trivially works. */
879 if (REG_P (in))
880 return 1;
882 /* To test MEMs properly, we'd have to take into account all the reloads
883 that are already scheduled, which can become quite complicated.
884 And since we've already handled address reloads for this MEM, it
885 should always succeed anyway. */
886 if (MEM_P (in))
887 return 1;
889 /* If we can make a simple SET insn that does the job, everything should
890 be fine. */
891 dst = gen_rtx_REG (mode, regno);
892 test_insn = make_insn_raw (gen_rtx_SET (dst, in));
893 save_recog_data = recog_data;
894 if (recog_memoized (test_insn) >= 0)
896 extract_insn (test_insn);
897 r = constrain_operands (1, get_enabled_alternatives (test_insn));
899 recog_data = save_recog_data;
900 return r;
903 /* Record one reload that needs to be performed.
904 IN is an rtx saying where the data are to be found before this instruction.
905 OUT says where they must be stored after the instruction.
906 (IN is zero for data not read, and OUT is zero for data not written.)
907 INLOC and OUTLOC point to the places in the instructions where
908 IN and OUT were found.
909 If IN and OUT are both nonzero, it means the same register must be used
910 to reload both IN and OUT.
912 RCLASS is a register class required for the reloaded data.
913 INMODE is the machine mode that the instruction requires
914 for the reg that replaces IN and OUTMODE is likewise for OUT.
916 If IN is zero, then OUT's location and mode should be passed as
917 INLOC and INMODE.
919 STRICT_LOW is the 1 if there is a containing STRICT_LOW_PART rtx.
921 OPTIONAL nonzero means this reload does not need to be performed:
922 it can be discarded if that is more convenient.
924 OPNUM and TYPE say what the purpose of this reload is.
926 The return value is the reload-number for this reload.
928 If both IN and OUT are nonzero, in some rare cases we might
929 want to make two separate reloads. (Actually we never do this now.)
930 Therefore, the reload-number for OUT is stored in
931 output_reloadnum when we return; the return value applies to IN.
932 Usually (presently always), when IN and OUT are nonzero,
933 the two reload-numbers are equal, but the caller should be careful to
934 distinguish them. */
937 push_reload (rtx in, rtx out, rtx *inloc, rtx *outloc,
938 enum reg_class rclass, machine_mode inmode,
939 machine_mode outmode, int strict_low, int optional,
940 int opnum, enum reload_type type)
942 int i;
943 int dont_share = 0;
944 int dont_remove_subreg = 0;
945 #ifdef LIMIT_RELOAD_CLASS
946 rtx *in_subreg_loc = 0, *out_subreg_loc = 0;
947 #endif
948 int secondary_in_reload = -1, secondary_out_reload = -1;
949 enum insn_code secondary_in_icode = CODE_FOR_nothing;
950 enum insn_code secondary_out_icode = CODE_FOR_nothing;
951 enum reg_class subreg_in_class ATTRIBUTE_UNUSED;
952 subreg_in_class = NO_REGS;
954 /* INMODE and/or OUTMODE could be VOIDmode if no mode
955 has been specified for the operand. In that case,
956 use the operand's mode as the mode to reload. */
957 if (inmode == VOIDmode && in != 0)
958 inmode = GET_MODE (in);
959 if (outmode == VOIDmode && out != 0)
960 outmode = GET_MODE (out);
962 /* If find_reloads and friends until now missed to replace a pseudo
963 with a constant of reg_equiv_constant something went wrong
964 beforehand.
965 Note that it can't simply be done here if we missed it earlier
966 since the constant might need to be pushed into the literal pool
967 and the resulting memref would probably need further
968 reloading. */
969 if (in != 0 && REG_P (in))
971 int regno = REGNO (in);
973 gcc_assert (regno < FIRST_PSEUDO_REGISTER
974 || reg_renumber[regno] >= 0
975 || reg_equiv_constant (regno) == NULL_RTX);
978 /* reg_equiv_constant only contains constants which are obviously
979 not appropriate as destination. So if we would need to replace
980 the destination pseudo with a constant we are in real
981 trouble. */
982 if (out != 0 && REG_P (out))
984 int regno = REGNO (out);
986 gcc_assert (regno < FIRST_PSEUDO_REGISTER
987 || reg_renumber[regno] >= 0
988 || reg_equiv_constant (regno) == NULL_RTX);
991 /* If we have a read-write operand with an address side-effect,
992 change either IN or OUT so the side-effect happens only once. */
993 if (in != 0 && out != 0 && MEM_P (in) && rtx_equal_p (in, out))
994 switch (GET_CODE (XEXP (in, 0)))
996 case POST_INC: case POST_DEC: case POST_MODIFY:
997 in = replace_equiv_address_nv (in, XEXP (XEXP (in, 0), 0));
998 break;
1000 case PRE_INC: case PRE_DEC: case PRE_MODIFY:
1001 out = replace_equiv_address_nv (out, XEXP (XEXP (out, 0), 0));
1002 break;
1004 default:
1005 break;
1008 /* If we are reloading a (SUBREG constant ...), really reload just the
1009 inside expression in its own mode. Similarly for (SUBREG (PLUS ...)).
1010 If we have (SUBREG:M1 (MEM:M2 ...) ...) (or an inner REG that is still
1011 a pseudo and hence will become a MEM) with M1 wider than M2 and the
1012 register is a pseudo, also reload the inside expression.
1013 For machines that extend byte loads, do this for any SUBREG of a pseudo
1014 where both M1 and M2 are a word or smaller, M1 is wider than M2, and
1015 M2 is an integral mode that gets extended when loaded.
1016 Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1017 where either M1 is not valid for R or M2 is wider than a word but we
1018 only need one register to store an M2-sized quantity in R.
1019 (However, if OUT is nonzero, we need to reload the reg *and*
1020 the subreg, so do nothing here, and let following statement handle it.)
1022 Note that the case of (SUBREG (CONST_INT...)...) is handled elsewhere;
1023 we can't handle it here because CONST_INT does not indicate a mode.
1025 Similarly, we must reload the inside expression if we have a
1026 STRICT_LOW_PART (presumably, in == out in this case).
1028 Also reload the inner expression if it does not require a secondary
1029 reload but the SUBREG does.
1031 Finally, reload the inner expression if it is a register that is in
1032 the class whose registers cannot be referenced in a different size
1033 and M1 is not the same size as M2. If subreg_lowpart_p is false, we
1034 cannot reload just the inside since we might end up with the wrong
1035 register class. But if it is inside a STRICT_LOW_PART, we have
1036 no choice, so we hope we do get the right register class there. */
1038 scalar_int_mode inner_mode;
1039 if (in != 0 && GET_CODE (in) == SUBREG
1040 && (subreg_lowpart_p (in) || strict_low)
1041 && targetm.can_change_mode_class (GET_MODE (SUBREG_REG (in)),
1042 inmode, rclass)
1043 && contains_allocatable_reg_of_mode[rclass][GET_MODE (SUBREG_REG (in))]
1044 && (CONSTANT_P (SUBREG_REG (in))
1045 || GET_CODE (SUBREG_REG (in)) == PLUS
1046 || strict_low
1047 || (((REG_P (SUBREG_REG (in))
1048 && REGNO (SUBREG_REG (in)) >= FIRST_PSEUDO_REGISTER)
1049 || MEM_P (SUBREG_REG (in)))
1050 && (paradoxical_subreg_p (inmode, GET_MODE (SUBREG_REG (in)))
1051 || (GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1052 && is_a <scalar_int_mode> (GET_MODE (SUBREG_REG (in)),
1053 &inner_mode)
1054 && GET_MODE_SIZE (inner_mode) <= UNITS_PER_WORD
1055 && paradoxical_subreg_p (inmode, inner_mode)
1056 && LOAD_EXTEND_OP (inner_mode) != UNKNOWN)
1057 || (WORD_REGISTER_OPERATIONS
1058 && partial_subreg_p (inmode, GET_MODE (SUBREG_REG (in)))
1059 && ((GET_MODE_SIZE (inmode) - 1) / UNITS_PER_WORD ==
1060 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))) - 1)
1061 / UNITS_PER_WORD)))))
1062 || (REG_P (SUBREG_REG (in))
1063 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1064 /* The case where out is nonzero
1065 is handled differently in the following statement. */
1066 && (out == 0 || subreg_lowpart_p (in))
1067 && ((GET_MODE_SIZE (inmode) <= UNITS_PER_WORD
1068 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1069 > UNITS_PER_WORD)
1070 && ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1071 / UNITS_PER_WORD)
1072 != REG_NREGS (SUBREG_REG (in))))
1073 || !targetm.hard_regno_mode_ok (subreg_regno (in), inmode)))
1074 || (secondary_reload_class (1, rclass, inmode, in) != NO_REGS
1075 && (secondary_reload_class (1, rclass, GET_MODE (SUBREG_REG (in)),
1076 SUBREG_REG (in))
1077 == NO_REGS))
1078 || (REG_P (SUBREG_REG (in))
1079 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1080 && !REG_CAN_CHANGE_MODE_P (REGNO (SUBREG_REG (in)),
1081 GET_MODE (SUBREG_REG (in)), inmode))))
1083 #ifdef LIMIT_RELOAD_CLASS
1084 in_subreg_loc = inloc;
1085 #endif
1086 inloc = &SUBREG_REG (in);
1087 in = *inloc;
1089 if (!WORD_REGISTER_OPERATIONS
1090 && LOAD_EXTEND_OP (GET_MODE (in)) == UNKNOWN
1091 && MEM_P (in))
1092 /* This is supposed to happen only for paradoxical subregs made by
1093 combine.c. (SUBREG (MEM)) isn't supposed to occur other ways. */
1094 gcc_assert (GET_MODE_SIZE (GET_MODE (in)) <= GET_MODE_SIZE (inmode));
1096 inmode = GET_MODE (in);
1099 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1100 where M1 is not valid for R if it was not handled by the code above.
1102 Similar issue for (SUBREG constant ...) if it was not handled by the
1103 code above. This can happen if SUBREG_BYTE != 0.
1105 However, we must reload the inner reg *as well as* the subreg in
1106 that case. */
1108 if (in != 0 && reload_inner_reg_of_subreg (in, inmode, false))
1110 if (REG_P (SUBREG_REG (in)))
1111 subreg_in_class
1112 = find_valid_class (inmode, GET_MODE (SUBREG_REG (in)),
1113 subreg_regno_offset (REGNO (SUBREG_REG (in)),
1114 GET_MODE (SUBREG_REG (in)),
1115 SUBREG_BYTE (in),
1116 GET_MODE (in)),
1117 REGNO (SUBREG_REG (in)));
1118 else if (CONSTANT_P (SUBREG_REG (in))
1119 || GET_CODE (SUBREG_REG (in)) == PLUS)
1120 subreg_in_class = find_valid_class_1 (inmode,
1121 GET_MODE (SUBREG_REG (in)),
1122 rclass);
1124 /* This relies on the fact that emit_reload_insns outputs the
1125 instructions for input reloads of type RELOAD_OTHER in the same
1126 order as the reloads. Thus if the outer reload is also of type
1127 RELOAD_OTHER, we are guaranteed that this inner reload will be
1128 output before the outer reload. */
1129 push_reload (SUBREG_REG (in), NULL_RTX, &SUBREG_REG (in), (rtx *) 0,
1130 subreg_in_class, VOIDmode, VOIDmode, 0, 0, opnum, type);
1131 dont_remove_subreg = 1;
1134 /* Similarly for paradoxical and problematical SUBREGs on the output.
1135 Note that there is no reason we need worry about the previous value
1136 of SUBREG_REG (out); even if wider than out, storing in a subreg is
1137 entitled to clobber it all (except in the case of a word mode subreg
1138 or of a STRICT_LOW_PART, in that latter case the constraint should
1139 label it input-output.) */
1140 if (out != 0 && GET_CODE (out) == SUBREG
1141 && (subreg_lowpart_p (out) || strict_low)
1142 && targetm.can_change_mode_class (GET_MODE (SUBREG_REG (out)),
1143 outmode, rclass)
1144 && contains_allocatable_reg_of_mode[rclass][GET_MODE (SUBREG_REG (out))]
1145 && (CONSTANT_P (SUBREG_REG (out))
1146 || strict_low
1147 || (((REG_P (SUBREG_REG (out))
1148 && REGNO (SUBREG_REG (out)) >= FIRST_PSEUDO_REGISTER)
1149 || MEM_P (SUBREG_REG (out)))
1150 && (paradoxical_subreg_p (outmode, GET_MODE (SUBREG_REG (out)))
1151 || (WORD_REGISTER_OPERATIONS
1152 && partial_subreg_p (outmode, GET_MODE (SUBREG_REG (out)))
1153 && ((GET_MODE_SIZE (outmode) - 1) / UNITS_PER_WORD ==
1154 ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))) - 1)
1155 / UNITS_PER_WORD)))))
1156 || (REG_P (SUBREG_REG (out))
1157 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1158 /* The case of a word mode subreg
1159 is handled differently in the following statement. */
1160 && ! (GET_MODE_SIZE (outmode) <= UNITS_PER_WORD
1161 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (out)))
1162 > UNITS_PER_WORD))
1163 && !targetm.hard_regno_mode_ok (subreg_regno (out), outmode))
1164 || (secondary_reload_class (0, rclass, outmode, out) != NO_REGS
1165 && (secondary_reload_class (0, rclass, GET_MODE (SUBREG_REG (out)),
1166 SUBREG_REG (out))
1167 == NO_REGS))
1168 || (REG_P (SUBREG_REG (out))
1169 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1170 && !REG_CAN_CHANGE_MODE_P (REGNO (SUBREG_REG (out)),
1171 GET_MODE (SUBREG_REG (out)),
1172 outmode))))
1174 #ifdef LIMIT_RELOAD_CLASS
1175 out_subreg_loc = outloc;
1176 #endif
1177 outloc = &SUBREG_REG (out);
1178 out = *outloc;
1179 gcc_assert (WORD_REGISTER_OPERATIONS || !MEM_P (out)
1180 || GET_MODE_SIZE (GET_MODE (out))
1181 <= GET_MODE_SIZE (outmode));
1182 outmode = GET_MODE (out);
1185 /* Similar issue for (SUBREG:M1 (REG:M2 ...) ...) for a hard register R
1186 where either M1 is not valid for R or M2 is wider than a word but we
1187 only need one register to store an M2-sized quantity in R.
1189 However, we must reload the inner reg *as well as* the subreg in
1190 that case and the inner reg is an in-out reload. */
1192 if (out != 0 && reload_inner_reg_of_subreg (out, outmode, true))
1194 enum reg_class in_out_class
1195 = find_valid_class (outmode, GET_MODE (SUBREG_REG (out)),
1196 subreg_regno_offset (REGNO (SUBREG_REG (out)),
1197 GET_MODE (SUBREG_REG (out)),
1198 SUBREG_BYTE (out),
1199 GET_MODE (out)),
1200 REGNO (SUBREG_REG (out)));
1202 /* This relies on the fact that emit_reload_insns outputs the
1203 instructions for output reloads of type RELOAD_OTHER in reverse
1204 order of the reloads. Thus if the outer reload is also of type
1205 RELOAD_OTHER, we are guaranteed that this inner reload will be
1206 output after the outer reload. */
1207 push_reload (SUBREG_REG (out), SUBREG_REG (out), &SUBREG_REG (out),
1208 &SUBREG_REG (out), in_out_class, VOIDmode, VOIDmode,
1209 0, 0, opnum, RELOAD_OTHER);
1210 dont_remove_subreg = 1;
1213 /* If IN appears in OUT, we can't share any input-only reload for IN. */
1214 if (in != 0 && out != 0 && MEM_P (out)
1215 && (REG_P (in) || MEM_P (in) || GET_CODE (in) == PLUS)
1216 && reg_overlap_mentioned_for_reload_p (in, XEXP (out, 0)))
1217 dont_share = 1;
1219 /* If IN is a SUBREG of a hard register, make a new REG. This
1220 simplifies some of the cases below. */
1222 if (in != 0 && GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))
1223 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER
1224 && ! dont_remove_subreg)
1225 in = gen_rtx_REG (GET_MODE (in), subreg_regno (in));
1227 /* Similarly for OUT. */
1228 if (out != 0 && GET_CODE (out) == SUBREG
1229 && REG_P (SUBREG_REG (out))
1230 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER
1231 && ! dont_remove_subreg)
1232 out = gen_rtx_REG (GET_MODE (out), subreg_regno (out));
1234 /* Narrow down the class of register wanted if that is
1235 desirable on this machine for efficiency. */
1237 reg_class_t preferred_class = rclass;
1239 if (in != 0)
1240 preferred_class = targetm.preferred_reload_class (in, rclass);
1242 /* Output reloads may need analogous treatment, different in detail. */
1243 if (out != 0)
1244 preferred_class
1245 = targetm.preferred_output_reload_class (out, preferred_class);
1247 /* Discard what the target said if we cannot do it. */
1248 if (preferred_class != NO_REGS
1249 || (optional && type == RELOAD_FOR_OUTPUT))
1250 rclass = (enum reg_class) preferred_class;
1253 /* Make sure we use a class that can handle the actual pseudo
1254 inside any subreg. For example, on the 386, QImode regs
1255 can appear within SImode subregs. Although GENERAL_REGS
1256 can handle SImode, QImode needs a smaller class. */
1257 #ifdef LIMIT_RELOAD_CLASS
1258 if (in_subreg_loc)
1259 rclass = LIMIT_RELOAD_CLASS (inmode, rclass);
1260 else if (in != 0 && GET_CODE (in) == SUBREG)
1261 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (in)), rclass);
1263 if (out_subreg_loc)
1264 rclass = LIMIT_RELOAD_CLASS (outmode, rclass);
1265 if (out != 0 && GET_CODE (out) == SUBREG)
1266 rclass = LIMIT_RELOAD_CLASS (GET_MODE (SUBREG_REG (out)), rclass);
1267 #endif
1269 /* Verify that this class is at least possible for the mode that
1270 is specified. */
1271 if (this_insn_is_asm)
1273 machine_mode mode;
1274 if (paradoxical_subreg_p (inmode, outmode))
1275 mode = inmode;
1276 else
1277 mode = outmode;
1278 if (mode == VOIDmode)
1280 error_for_asm (this_insn, "cannot reload integer constant "
1281 "operand in %<asm%>");
1282 mode = word_mode;
1283 if (in != 0)
1284 inmode = word_mode;
1285 if (out != 0)
1286 outmode = word_mode;
1288 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1289 if (targetm.hard_regno_mode_ok (i, mode)
1290 && in_hard_reg_set_p (reg_class_contents[(int) rclass], mode, i))
1291 break;
1292 if (i == FIRST_PSEUDO_REGISTER)
1294 error_for_asm (this_insn, "impossible register constraint "
1295 "in %<asm%>");
1296 /* Avoid further trouble with this insn. */
1297 PATTERN (this_insn) = gen_rtx_USE (VOIDmode, const0_rtx);
1298 /* We used to continue here setting class to ALL_REGS, but it triggers
1299 sanity check on i386 for:
1300 void foo(long double d)
1302 asm("" :: "a" (d));
1304 Returning zero here ought to be safe as we take care in
1305 find_reloads to not process the reloads when instruction was
1306 replaced by USE. */
1308 return 0;
1312 /* Optional output reloads are always OK even if we have no register class,
1313 since the function of these reloads is only to have spill_reg_store etc.
1314 set, so that the storing insn can be deleted later. */
1315 gcc_assert (rclass != NO_REGS
1316 || (optional != 0 && type == RELOAD_FOR_OUTPUT));
1318 i = find_reusable_reload (&in, out, rclass, type, opnum, dont_share);
1320 if (i == n_reloads)
1322 /* See if we need a secondary reload register to move between CLASS
1323 and IN or CLASS and OUT. Get the icode and push any required reloads
1324 needed for each of them if so. */
1326 if (in != 0)
1327 secondary_in_reload
1328 = push_secondary_reload (1, in, opnum, optional, rclass, inmode, type,
1329 &secondary_in_icode, NULL);
1330 if (out != 0 && GET_CODE (out) != SCRATCH)
1331 secondary_out_reload
1332 = push_secondary_reload (0, out, opnum, optional, rclass, outmode,
1333 type, &secondary_out_icode, NULL);
1335 /* We found no existing reload suitable for re-use.
1336 So add an additional reload. */
1338 if (subreg_in_class == NO_REGS
1339 && in != 0
1340 && (REG_P (in)
1341 || (GET_CODE (in) == SUBREG && REG_P (SUBREG_REG (in))))
1342 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER)
1343 subreg_in_class = REGNO_REG_CLASS (reg_or_subregno (in));
1344 /* If a memory location is needed for the copy, make one. */
1345 if (subreg_in_class != NO_REGS
1346 && targetm.secondary_memory_needed (inmode, subreg_in_class, rclass))
1347 get_secondary_mem (in, inmode, opnum, type);
1349 i = n_reloads;
1350 rld[i].in = in;
1351 rld[i].out = out;
1352 rld[i].rclass = rclass;
1353 rld[i].inmode = inmode;
1354 rld[i].outmode = outmode;
1355 rld[i].reg_rtx = 0;
1356 rld[i].optional = optional;
1357 rld[i].inc = 0;
1358 rld[i].nocombine = 0;
1359 rld[i].in_reg = inloc ? *inloc : 0;
1360 rld[i].out_reg = outloc ? *outloc : 0;
1361 rld[i].opnum = opnum;
1362 rld[i].when_needed = type;
1363 rld[i].secondary_in_reload = secondary_in_reload;
1364 rld[i].secondary_out_reload = secondary_out_reload;
1365 rld[i].secondary_in_icode = secondary_in_icode;
1366 rld[i].secondary_out_icode = secondary_out_icode;
1367 rld[i].secondary_p = 0;
1369 n_reloads++;
1371 if (out != 0
1372 && (REG_P (out)
1373 || (GET_CODE (out) == SUBREG && REG_P (SUBREG_REG (out))))
1374 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
1375 && (targetm.secondary_memory_needed
1376 (outmode, rclass, REGNO_REG_CLASS (reg_or_subregno (out)))))
1377 get_secondary_mem (out, outmode, opnum, type);
1379 else
1381 /* We are reusing an existing reload,
1382 but we may have additional information for it.
1383 For example, we may now have both IN and OUT
1384 while the old one may have just one of them. */
1386 /* The modes can be different. If they are, we want to reload in
1387 the larger mode, so that the value is valid for both modes. */
1388 if (inmode != VOIDmode
1389 && partial_subreg_p (rld[i].inmode, inmode))
1390 rld[i].inmode = inmode;
1391 if (outmode != VOIDmode
1392 && partial_subreg_p (rld[i].outmode, outmode))
1393 rld[i].outmode = outmode;
1394 if (in != 0)
1396 rtx in_reg = inloc ? *inloc : 0;
1397 /* If we merge reloads for two distinct rtl expressions that
1398 are identical in content, there might be duplicate address
1399 reloads. Remove the extra set now, so that if we later find
1400 that we can inherit this reload, we can get rid of the
1401 address reloads altogether.
1403 Do not do this if both reloads are optional since the result
1404 would be an optional reload which could potentially leave
1405 unresolved address replacements.
1407 It is not sufficient to call transfer_replacements since
1408 choose_reload_regs will remove the replacements for address
1409 reloads of inherited reloads which results in the same
1410 problem. */
1411 if (rld[i].in != in && rtx_equal_p (in, rld[i].in)
1412 && ! (rld[i].optional && optional))
1414 /* We must keep the address reload with the lower operand
1415 number alive. */
1416 if (opnum > rld[i].opnum)
1418 remove_address_replacements (in);
1419 in = rld[i].in;
1420 in_reg = rld[i].in_reg;
1422 else
1423 remove_address_replacements (rld[i].in);
1425 /* When emitting reloads we don't necessarily look at the in-
1426 and outmode, but also directly at the operands (in and out).
1427 So we can't simply overwrite them with whatever we have found
1428 for this (to-be-merged) reload, we have to "merge" that too.
1429 Reusing another reload already verified that we deal with the
1430 same operands, just possibly in different modes. So we
1431 overwrite the operands only when the new mode is larger.
1432 See also PR33613. */
1433 if (!rld[i].in
1434 || partial_subreg_p (GET_MODE (rld[i].in), GET_MODE (in)))
1435 rld[i].in = in;
1436 if (!rld[i].in_reg
1437 || (in_reg
1438 && partial_subreg_p (GET_MODE (rld[i].in_reg),
1439 GET_MODE (in_reg))))
1440 rld[i].in_reg = in_reg;
1442 if (out != 0)
1444 if (!rld[i].out
1445 || (out
1446 && partial_subreg_p (GET_MODE (rld[i].out),
1447 GET_MODE (out))))
1448 rld[i].out = out;
1449 if (outloc
1450 && (!rld[i].out_reg
1451 || partial_subreg_p (GET_MODE (rld[i].out_reg),
1452 GET_MODE (*outloc))))
1453 rld[i].out_reg = *outloc;
1455 if (reg_class_subset_p (rclass, rld[i].rclass))
1456 rld[i].rclass = rclass;
1457 rld[i].optional &= optional;
1458 if (MERGE_TO_OTHER (type, rld[i].when_needed,
1459 opnum, rld[i].opnum))
1460 rld[i].when_needed = RELOAD_OTHER;
1461 rld[i].opnum = MIN (rld[i].opnum, opnum);
1464 /* If the ostensible rtx being reloaded differs from the rtx found
1465 in the location to substitute, this reload is not safe to combine
1466 because we cannot reliably tell whether it appears in the insn. */
1468 if (in != 0 && in != *inloc)
1469 rld[i].nocombine = 1;
1471 #if 0
1472 /* This was replaced by changes in find_reloads_address_1 and the new
1473 function inc_for_reload, which go with a new meaning of reload_inc. */
1475 /* If this is an IN/OUT reload in an insn that sets the CC,
1476 it must be for an autoincrement. It doesn't work to store
1477 the incremented value after the insn because that would clobber the CC.
1478 So we must do the increment of the value reloaded from,
1479 increment it, store it back, then decrement again. */
1480 if (out != 0 && sets_cc0_p (PATTERN (this_insn)))
1482 out = 0;
1483 rld[i].out = 0;
1484 rld[i].inc = find_inc_amount (PATTERN (this_insn), in);
1485 /* If we did not find a nonzero amount-to-increment-by,
1486 that contradicts the belief that IN is being incremented
1487 in an address in this insn. */
1488 gcc_assert (rld[i].inc != 0);
1490 #endif
1492 /* If we will replace IN and OUT with the reload-reg,
1493 record where they are located so that substitution need
1494 not do a tree walk. */
1496 if (replace_reloads)
1498 if (inloc != 0)
1500 struct replacement *r = &replacements[n_replacements++];
1501 r->what = i;
1502 r->where = inloc;
1503 r->mode = inmode;
1505 if (outloc != 0 && outloc != inloc)
1507 struct replacement *r = &replacements[n_replacements++];
1508 r->what = i;
1509 r->where = outloc;
1510 r->mode = outmode;
1514 /* If this reload is just being introduced and it has both
1515 an incoming quantity and an outgoing quantity that are
1516 supposed to be made to match, see if either one of the two
1517 can serve as the place to reload into.
1519 If one of them is acceptable, set rld[i].reg_rtx
1520 to that one. */
1522 if (in != 0 && out != 0 && in != out && rld[i].reg_rtx == 0)
1524 rld[i].reg_rtx = find_dummy_reload (in, out, inloc, outloc,
1525 inmode, outmode,
1526 rld[i].rclass, i,
1527 earlyclobber_operand_p (out));
1529 /* If the outgoing register already contains the same value
1530 as the incoming one, we can dispense with loading it.
1531 The easiest way to tell the caller that is to give a phony
1532 value for the incoming operand (same as outgoing one). */
1533 if (rld[i].reg_rtx == out
1534 && (REG_P (in) || CONSTANT_P (in))
1535 && find_equiv_reg (in, this_insn, NO_REGS, REGNO (out),
1536 static_reload_reg_p, i, inmode) != 0)
1537 rld[i].in = out;
1540 /* If this is an input reload and the operand contains a register that
1541 dies in this insn and is used nowhere else, see if it is the right class
1542 to be used for this reload. Use it if so. (This occurs most commonly
1543 in the case of paradoxical SUBREGs and in-out reloads). We cannot do
1544 this if it is also an output reload that mentions the register unless
1545 the output is a SUBREG that clobbers an entire register.
1547 Note that the operand might be one of the spill regs, if it is a
1548 pseudo reg and we are in a block where spilling has not taken place.
1549 But if there is no spilling in this block, that is OK.
1550 An explicitly used hard reg cannot be a spill reg. */
1552 if (rld[i].reg_rtx == 0 && in != 0 && hard_regs_live_known)
1554 rtx note;
1555 int regno;
1556 machine_mode rel_mode = inmode;
1558 if (out && partial_subreg_p (rel_mode, outmode))
1559 rel_mode = outmode;
1561 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1562 if (REG_NOTE_KIND (note) == REG_DEAD
1563 && REG_P (XEXP (note, 0))
1564 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1565 && reg_mentioned_p (XEXP (note, 0), in)
1566 /* Check that a former pseudo is valid; see find_dummy_reload. */
1567 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1568 || (! bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
1569 ORIGINAL_REGNO (XEXP (note, 0)))
1570 && REG_NREGS (XEXP (note, 0)) == 1))
1571 && ! refers_to_regno_for_reload_p (regno,
1572 end_hard_regno (rel_mode,
1573 regno),
1574 PATTERN (this_insn), inloc)
1575 && ! find_reg_fusage (this_insn, USE, XEXP (note, 0))
1576 /* If this is also an output reload, IN cannot be used as
1577 the reload register if it is set in this insn unless IN
1578 is also OUT. */
1579 && (out == 0 || in == out
1580 || ! hard_reg_set_here_p (regno,
1581 end_hard_regno (rel_mode, regno),
1582 PATTERN (this_insn)))
1583 /* ??? Why is this code so different from the previous?
1584 Is there any simple coherent way to describe the two together?
1585 What's going on here. */
1586 && (in != out
1587 || (GET_CODE (in) == SUBREG
1588 && (((GET_MODE_SIZE (GET_MODE (in)) + (UNITS_PER_WORD - 1))
1589 / UNITS_PER_WORD)
1590 == ((GET_MODE_SIZE (GET_MODE (SUBREG_REG (in)))
1591 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD))))
1592 /* Make sure the operand fits in the reg that dies. */
1593 && (GET_MODE_SIZE (rel_mode)
1594 <= GET_MODE_SIZE (GET_MODE (XEXP (note, 0))))
1595 && targetm.hard_regno_mode_ok (regno, inmode)
1596 && targetm.hard_regno_mode_ok (regno, outmode))
1598 unsigned int offs;
1599 unsigned int nregs = MAX (hard_regno_nregs (regno, inmode),
1600 hard_regno_nregs (regno, outmode));
1602 for (offs = 0; offs < nregs; offs++)
1603 if (fixed_regs[regno + offs]
1604 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
1605 regno + offs))
1606 break;
1608 if (offs == nregs
1609 && (! (refers_to_regno_for_reload_p
1610 (regno, end_hard_regno (inmode, regno), in, (rtx *) 0))
1611 || can_reload_into (in, regno, inmode)))
1613 rld[i].reg_rtx = gen_rtx_REG (rel_mode, regno);
1614 break;
1619 if (out)
1620 output_reloadnum = i;
1622 return i;
1625 /* Record an additional place we must replace a value
1626 for which we have already recorded a reload.
1627 RELOADNUM is the value returned by push_reload
1628 when the reload was recorded.
1629 This is used in insn patterns that use match_dup. */
1631 static void
1632 push_replacement (rtx *loc, int reloadnum, machine_mode mode)
1634 if (replace_reloads)
1636 struct replacement *r = &replacements[n_replacements++];
1637 r->what = reloadnum;
1638 r->where = loc;
1639 r->mode = mode;
1643 /* Duplicate any replacement we have recorded to apply at
1644 location ORIG_LOC to also be performed at DUP_LOC.
1645 This is used in insn patterns that use match_dup. */
1647 static void
1648 dup_replacements (rtx *dup_loc, rtx *orig_loc)
1650 int i, n = n_replacements;
1652 for (i = 0; i < n; i++)
1654 struct replacement *r = &replacements[i];
1655 if (r->where == orig_loc)
1656 push_replacement (dup_loc, r->what, r->mode);
1660 /* Transfer all replacements that used to be in reload FROM to be in
1661 reload TO. */
1663 void
1664 transfer_replacements (int to, int from)
1666 int i;
1668 for (i = 0; i < n_replacements; i++)
1669 if (replacements[i].what == from)
1670 replacements[i].what = to;
1673 /* IN_RTX is the value loaded by a reload that we now decided to inherit,
1674 or a subpart of it. If we have any replacements registered for IN_RTX,
1675 cancel the reloads that were supposed to load them.
1676 Return nonzero if we canceled any reloads. */
1678 remove_address_replacements (rtx in_rtx)
1680 int i, j;
1681 char reload_flags[MAX_RELOADS];
1682 int something_changed = 0;
1684 memset (reload_flags, 0, sizeof reload_flags);
1685 for (i = 0, j = 0; i < n_replacements; i++)
1687 if (loc_mentioned_in_p (replacements[i].where, in_rtx))
1688 reload_flags[replacements[i].what] |= 1;
1689 else
1691 replacements[j++] = replacements[i];
1692 reload_flags[replacements[i].what] |= 2;
1695 /* Note that the following store must be done before the recursive calls. */
1696 n_replacements = j;
1698 for (i = n_reloads - 1; i >= 0; i--)
1700 if (reload_flags[i] == 1)
1702 deallocate_reload_reg (i);
1703 remove_address_replacements (rld[i].in);
1704 rld[i].in = 0;
1705 something_changed = 1;
1708 return something_changed;
1711 /* If there is only one output reload, and it is not for an earlyclobber
1712 operand, try to combine it with a (logically unrelated) input reload
1713 to reduce the number of reload registers needed.
1715 This is safe if the input reload does not appear in
1716 the value being output-reloaded, because this implies
1717 it is not needed any more once the original insn completes.
1719 If that doesn't work, see we can use any of the registers that
1720 die in this insn as a reload register. We can if it is of the right
1721 class and does not appear in the value being output-reloaded. */
1723 static void
1724 combine_reloads (void)
1726 int i, regno;
1727 int output_reload = -1;
1728 int secondary_out = -1;
1729 rtx note;
1731 /* Find the output reload; return unless there is exactly one
1732 and that one is mandatory. */
1734 for (i = 0; i < n_reloads; i++)
1735 if (rld[i].out != 0)
1737 if (output_reload >= 0)
1738 return;
1739 output_reload = i;
1742 if (output_reload < 0 || rld[output_reload].optional)
1743 return;
1745 /* An input-output reload isn't combinable. */
1747 if (rld[output_reload].in != 0)
1748 return;
1750 /* If this reload is for an earlyclobber operand, we can't do anything. */
1751 if (earlyclobber_operand_p (rld[output_reload].out))
1752 return;
1754 /* If there is a reload for part of the address of this operand, we would
1755 need to change it to RELOAD_FOR_OTHER_ADDRESS. But that would extend
1756 its life to the point where doing this combine would not lower the
1757 number of spill registers needed. */
1758 for (i = 0; i < n_reloads; i++)
1759 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
1760 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
1761 && rld[i].opnum == rld[output_reload].opnum)
1762 return;
1764 /* Check each input reload; can we combine it? */
1766 for (i = 0; i < n_reloads; i++)
1767 if (rld[i].in && ! rld[i].optional && ! rld[i].nocombine
1768 /* Life span of this reload must not extend past main insn. */
1769 && rld[i].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
1770 && rld[i].when_needed != RELOAD_FOR_OUTADDR_ADDRESS
1771 && rld[i].when_needed != RELOAD_OTHER
1772 && (ira_reg_class_max_nregs [(int)rld[i].rclass][(int) rld[i].inmode]
1773 == ira_reg_class_max_nregs [(int) rld[output_reload].rclass]
1774 [(int) rld[output_reload].outmode])
1775 && known_eq (rld[i].inc, 0)
1776 && rld[i].reg_rtx == 0
1777 /* Don't combine two reloads with different secondary
1778 memory locations. */
1779 && (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum] == 0
1780 || secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] == 0
1781 || rtx_equal_p (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum],
1782 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum]))
1783 && (targetm.small_register_classes_for_mode_p (VOIDmode)
1784 ? (rld[i].rclass == rld[output_reload].rclass)
1785 : (reg_class_subset_p (rld[i].rclass,
1786 rld[output_reload].rclass)
1787 || reg_class_subset_p (rld[output_reload].rclass,
1788 rld[i].rclass)))
1789 && (MATCHES (rld[i].in, rld[output_reload].out)
1790 /* Args reversed because the first arg seems to be
1791 the one that we imagine being modified
1792 while the second is the one that might be affected. */
1793 || (! reg_overlap_mentioned_for_reload_p (rld[output_reload].out,
1794 rld[i].in)
1795 /* However, if the input is a register that appears inside
1796 the output, then we also can't share.
1797 Imagine (set (mem (reg 69)) (plus (reg 69) ...)).
1798 If the same reload reg is used for both reg 69 and the
1799 result to be stored in memory, then that result
1800 will clobber the address of the memory ref. */
1801 && ! (REG_P (rld[i].in)
1802 && reg_overlap_mentioned_for_reload_p (rld[i].in,
1803 rld[output_reload].out))))
1804 && ! reload_inner_reg_of_subreg (rld[i].in, rld[i].inmode,
1805 rld[i].when_needed != RELOAD_FOR_INPUT)
1806 && (reg_class_size[(int) rld[i].rclass]
1807 || targetm.small_register_classes_for_mode_p (VOIDmode))
1808 /* We will allow making things slightly worse by combining an
1809 input and an output, but no worse than that. */
1810 && (rld[i].when_needed == RELOAD_FOR_INPUT
1811 || rld[i].when_needed == RELOAD_FOR_OUTPUT))
1813 int j;
1815 /* We have found a reload to combine with! */
1816 rld[i].out = rld[output_reload].out;
1817 rld[i].out_reg = rld[output_reload].out_reg;
1818 rld[i].outmode = rld[output_reload].outmode;
1819 /* Mark the old output reload as inoperative. */
1820 rld[output_reload].out = 0;
1821 /* The combined reload is needed for the entire insn. */
1822 rld[i].when_needed = RELOAD_OTHER;
1823 /* If the output reload had a secondary reload, copy it. */
1824 if (rld[output_reload].secondary_out_reload != -1)
1826 rld[i].secondary_out_reload
1827 = rld[output_reload].secondary_out_reload;
1828 rld[i].secondary_out_icode
1829 = rld[output_reload].secondary_out_icode;
1832 /* Copy any secondary MEM. */
1833 if (secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum] != 0)
1834 secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[i].opnum]
1835 = secondary_memlocs_elim[(int) rld[output_reload].outmode][rld[output_reload].opnum];
1836 /* If required, minimize the register class. */
1837 if (reg_class_subset_p (rld[output_reload].rclass,
1838 rld[i].rclass))
1839 rld[i].rclass = rld[output_reload].rclass;
1841 /* Transfer all replacements from the old reload to the combined. */
1842 for (j = 0; j < n_replacements; j++)
1843 if (replacements[j].what == output_reload)
1844 replacements[j].what = i;
1846 return;
1849 /* If this insn has only one operand that is modified or written (assumed
1850 to be the first), it must be the one corresponding to this reload. It
1851 is safe to use anything that dies in this insn for that output provided
1852 that it does not occur in the output (we already know it isn't an
1853 earlyclobber. If this is an asm insn, give up. */
1855 if (INSN_CODE (this_insn) == -1)
1856 return;
1858 for (i = 1; i < insn_data[INSN_CODE (this_insn)].n_operands; i++)
1859 if (insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '='
1860 || insn_data[INSN_CODE (this_insn)].operand[i].constraint[0] == '+')
1861 return;
1863 /* See if some hard register that dies in this insn and is not used in
1864 the output is the right class. Only works if the register we pick
1865 up can fully hold our output reload. */
1866 for (note = REG_NOTES (this_insn); note; note = XEXP (note, 1))
1867 if (REG_NOTE_KIND (note) == REG_DEAD
1868 && REG_P (XEXP (note, 0))
1869 && !reg_overlap_mentioned_for_reload_p (XEXP (note, 0),
1870 rld[output_reload].out)
1871 && (regno = REGNO (XEXP (note, 0))) < FIRST_PSEUDO_REGISTER
1872 && targetm.hard_regno_mode_ok (regno, rld[output_reload].outmode)
1873 && TEST_HARD_REG_BIT (reg_class_contents[(int) rld[output_reload].rclass],
1874 regno)
1875 && (hard_regno_nregs (regno, rld[output_reload].outmode)
1876 <= REG_NREGS (XEXP (note, 0)))
1877 /* Ensure that a secondary or tertiary reload for this output
1878 won't want this register. */
1879 && ((secondary_out = rld[output_reload].secondary_out_reload) == -1
1880 || (!(TEST_HARD_REG_BIT
1881 (reg_class_contents[(int) rld[secondary_out].rclass], regno))
1882 && ((secondary_out = rld[secondary_out].secondary_out_reload) == -1
1883 || !(TEST_HARD_REG_BIT
1884 (reg_class_contents[(int) rld[secondary_out].rclass],
1885 regno)))))
1886 && !fixed_regs[regno]
1887 /* Check that a former pseudo is valid; see find_dummy_reload. */
1888 && (ORIGINAL_REGNO (XEXP (note, 0)) < FIRST_PSEUDO_REGISTER
1889 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
1890 ORIGINAL_REGNO (XEXP (note, 0)))
1891 && REG_NREGS (XEXP (note, 0)) == 1)))
1893 rld[output_reload].reg_rtx
1894 = gen_rtx_REG (rld[output_reload].outmode, regno);
1895 return;
1899 /* Try to find a reload register for an in-out reload (expressions IN and OUT).
1900 See if one of IN and OUT is a register that may be used;
1901 this is desirable since a spill-register won't be needed.
1902 If so, return the register rtx that proves acceptable.
1904 INLOC and OUTLOC are locations where IN and OUT appear in the insn.
1905 RCLASS is the register class required for the reload.
1907 If FOR_REAL is >= 0, it is the number of the reload,
1908 and in some cases when it can be discovered that OUT doesn't need
1909 to be computed, clear out rld[FOR_REAL].out.
1911 If FOR_REAL is -1, this should not be done, because this call
1912 is just to see if a register can be found, not to find and install it.
1914 EARLYCLOBBER is nonzero if OUT is an earlyclobber operand. This
1915 puts an additional constraint on being able to use IN for OUT since
1916 IN must not appear elsewhere in the insn (it is assumed that IN itself
1917 is safe from the earlyclobber). */
1919 static rtx
1920 find_dummy_reload (rtx real_in, rtx real_out, rtx *inloc, rtx *outloc,
1921 machine_mode inmode, machine_mode outmode,
1922 reg_class_t rclass, int for_real, int earlyclobber)
1924 rtx in = real_in;
1925 rtx out = real_out;
1926 int in_offset = 0;
1927 int out_offset = 0;
1928 rtx value = 0;
1930 /* If operands exceed a word, we can't use either of them
1931 unless they have the same size. */
1932 if (GET_MODE_SIZE (outmode) != GET_MODE_SIZE (inmode)
1933 && (GET_MODE_SIZE (outmode) > UNITS_PER_WORD
1934 || GET_MODE_SIZE (inmode) > UNITS_PER_WORD))
1935 return 0;
1937 /* Note that {in,out}_offset are needed only when 'in' or 'out'
1938 respectively refers to a hard register. */
1940 /* Find the inside of any subregs. */
1941 while (GET_CODE (out) == SUBREG)
1943 if (REG_P (SUBREG_REG (out))
1944 && REGNO (SUBREG_REG (out)) < FIRST_PSEUDO_REGISTER)
1945 out_offset += subreg_regno_offset (REGNO (SUBREG_REG (out)),
1946 GET_MODE (SUBREG_REG (out)),
1947 SUBREG_BYTE (out),
1948 GET_MODE (out));
1949 out = SUBREG_REG (out);
1951 while (GET_CODE (in) == SUBREG)
1953 if (REG_P (SUBREG_REG (in))
1954 && REGNO (SUBREG_REG (in)) < FIRST_PSEUDO_REGISTER)
1955 in_offset += subreg_regno_offset (REGNO (SUBREG_REG (in)),
1956 GET_MODE (SUBREG_REG (in)),
1957 SUBREG_BYTE (in),
1958 GET_MODE (in));
1959 in = SUBREG_REG (in);
1962 /* Narrow down the reg class, the same way push_reload will;
1963 otherwise we might find a dummy now, but push_reload won't. */
1965 reg_class_t preferred_class = targetm.preferred_reload_class (in, rclass);
1966 if (preferred_class != NO_REGS)
1967 rclass = (enum reg_class) preferred_class;
1970 /* See if OUT will do. */
1971 if (REG_P (out)
1972 && REGNO (out) < FIRST_PSEUDO_REGISTER)
1974 unsigned int regno = REGNO (out) + out_offset;
1975 unsigned int nwords = hard_regno_nregs (regno, outmode);
1976 rtx saved_rtx;
1978 /* When we consider whether the insn uses OUT,
1979 ignore references within IN. They don't prevent us
1980 from copying IN into OUT, because those refs would
1981 move into the insn that reloads IN.
1983 However, we only ignore IN in its role as this reload.
1984 If the insn uses IN elsewhere and it contains OUT,
1985 that counts. We can't be sure it's the "same" operand
1986 so it might not go through this reload.
1988 We also need to avoid using OUT if it, or part of it, is a
1989 fixed register. Modifying such registers, even transiently,
1990 may have undefined effects on the machine, such as modifying
1991 the stack pointer. */
1992 saved_rtx = *inloc;
1993 *inloc = const0_rtx;
1995 if (regno < FIRST_PSEUDO_REGISTER
1996 && targetm.hard_regno_mode_ok (regno, outmode)
1997 && ! refers_to_regno_for_reload_p (regno, regno + nwords,
1998 PATTERN (this_insn), outloc))
2000 unsigned int i;
2002 for (i = 0; i < nwords; i++)
2003 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2004 regno + i)
2005 || fixed_regs[regno + i])
2006 break;
2008 if (i == nwords)
2010 if (REG_P (real_out))
2011 value = real_out;
2012 else
2013 value = gen_rtx_REG (outmode, regno);
2017 *inloc = saved_rtx;
2020 /* Consider using IN if OUT was not acceptable
2021 or if OUT dies in this insn (like the quotient in a divmod insn).
2022 We can't use IN unless it is dies in this insn,
2023 which means we must know accurately which hard regs are live.
2024 Also, the result can't go in IN if IN is used within OUT,
2025 or if OUT is an earlyclobber and IN appears elsewhere in the insn. */
2026 if (hard_regs_live_known
2027 && REG_P (in)
2028 && REGNO (in) < FIRST_PSEUDO_REGISTER
2029 && (value == 0
2030 || find_reg_note (this_insn, REG_UNUSED, real_out))
2031 && find_reg_note (this_insn, REG_DEAD, real_in)
2032 && !fixed_regs[REGNO (in)]
2033 && targetm.hard_regno_mode_ok (REGNO (in),
2034 /* The only case where out and real_out
2035 might have different modes is where
2036 real_out is a subreg, and in that
2037 case, out has a real mode. */
2038 (GET_MODE (out) != VOIDmode
2039 ? GET_MODE (out) : outmode))
2040 && (ORIGINAL_REGNO (in) < FIRST_PSEUDO_REGISTER
2041 /* However only do this if we can be sure that this input
2042 operand doesn't correspond with an uninitialized pseudo.
2043 global can assign some hardreg to it that is the same as
2044 the one assigned to a different, also live pseudo (as it
2045 can ignore the conflict). We must never introduce writes
2046 to such hardregs, as they would clobber the other live
2047 pseudo. See PR 20973. */
2048 || (!bitmap_bit_p (DF_LR_OUT (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
2049 ORIGINAL_REGNO (in))
2050 /* Similarly, only do this if we can be sure that the death
2051 note is still valid. global can assign some hardreg to
2052 the pseudo referenced in the note and simultaneously a
2053 subword of this hardreg to a different, also live pseudo,
2054 because only another subword of the hardreg is actually
2055 used in the insn. This cannot happen if the pseudo has
2056 been assigned exactly one hardreg. See PR 33732. */
2057 && REG_NREGS (in) == 1)))
2059 unsigned int regno = REGNO (in) + in_offset;
2060 unsigned int nwords = hard_regno_nregs (regno, inmode);
2062 if (! refers_to_regno_for_reload_p (regno, regno + nwords, out, (rtx*) 0)
2063 && ! hard_reg_set_here_p (regno, regno + nwords,
2064 PATTERN (this_insn))
2065 && (! earlyclobber
2066 || ! refers_to_regno_for_reload_p (regno, regno + nwords,
2067 PATTERN (this_insn), inloc)))
2069 unsigned int i;
2071 for (i = 0; i < nwords; i++)
2072 if (! TEST_HARD_REG_BIT (reg_class_contents[(int) rclass],
2073 regno + i))
2074 break;
2076 if (i == nwords)
2078 /* If we were going to use OUT as the reload reg
2079 and changed our mind, it means OUT is a dummy that
2080 dies here. So don't bother copying value to it. */
2081 if (for_real >= 0 && value == real_out)
2082 rld[for_real].out = 0;
2083 if (REG_P (real_in))
2084 value = real_in;
2085 else
2086 value = gen_rtx_REG (inmode, regno);
2091 return value;
2094 /* This page contains subroutines used mainly for determining
2095 whether the IN or an OUT of a reload can serve as the
2096 reload register. */
2098 /* Return 1 if X is an operand of an insn that is being earlyclobbered. */
2101 earlyclobber_operand_p (rtx x)
2103 int i;
2105 for (i = 0; i < n_earlyclobbers; i++)
2106 if (reload_earlyclobbers[i] == x)
2107 return 1;
2109 return 0;
2112 /* Return 1 if expression X alters a hard reg in the range
2113 from BEG_REGNO (inclusive) to END_REGNO (exclusive),
2114 either explicitly or in the guise of a pseudo-reg allocated to REGNO.
2115 X should be the body of an instruction. */
2117 static int
2118 hard_reg_set_here_p (unsigned int beg_regno, unsigned int end_regno, rtx x)
2120 if (GET_CODE (x) == SET || GET_CODE (x) == CLOBBER)
2122 rtx op0 = SET_DEST (x);
2124 while (GET_CODE (op0) == SUBREG)
2125 op0 = SUBREG_REG (op0);
2126 if (REG_P (op0))
2128 unsigned int r = REGNO (op0);
2130 /* See if this reg overlaps range under consideration. */
2131 if (r < end_regno
2132 && end_hard_regno (GET_MODE (op0), r) > beg_regno)
2133 return 1;
2136 else if (GET_CODE (x) == PARALLEL)
2138 int i = XVECLEN (x, 0) - 1;
2140 for (; i >= 0; i--)
2141 if (hard_reg_set_here_p (beg_regno, end_regno, XVECEXP (x, 0, i)))
2142 return 1;
2145 return 0;
2148 /* Return 1 if ADDR is a valid memory address for mode MODE
2149 in address space AS, and check that each pseudo reg has the
2150 proper kind of hard reg. */
2153 strict_memory_address_addr_space_p (machine_mode mode ATTRIBUTE_UNUSED,
2154 rtx addr, addr_space_t as)
2156 #ifdef GO_IF_LEGITIMATE_ADDRESS
2157 gcc_assert (ADDR_SPACE_GENERIC_P (as));
2158 GO_IF_LEGITIMATE_ADDRESS (mode, addr, win);
2159 return 0;
2161 win:
2162 return 1;
2163 #else
2164 return targetm.addr_space.legitimate_address_p (mode, addr, 1, as);
2165 #endif
2168 /* Like rtx_equal_p except that it allows a REG and a SUBREG to match
2169 if they are the same hard reg, and has special hacks for
2170 autoincrement and autodecrement.
2171 This is specifically intended for find_reloads to use
2172 in determining whether two operands match.
2173 X is the operand whose number is the lower of the two.
2175 The value is 2 if Y contains a pre-increment that matches
2176 a non-incrementing address in X. */
2178 /* ??? To be completely correct, we should arrange to pass
2179 for X the output operand and for Y the input operand.
2180 For now, we assume that the output operand has the lower number
2181 because that is natural in (SET output (... input ...)). */
2184 operands_match_p (rtx x, rtx y)
2186 int i;
2187 RTX_CODE code = GET_CODE (x);
2188 const char *fmt;
2189 int success_2;
2191 if (x == y)
2192 return 1;
2193 if ((code == REG || (code == SUBREG && REG_P (SUBREG_REG (x))))
2194 && (REG_P (y) || (GET_CODE (y) == SUBREG
2195 && REG_P (SUBREG_REG (y)))))
2197 int j;
2199 if (code == SUBREG)
2201 i = REGNO (SUBREG_REG (x));
2202 if (i >= FIRST_PSEUDO_REGISTER)
2203 goto slow;
2204 i += subreg_regno_offset (REGNO (SUBREG_REG (x)),
2205 GET_MODE (SUBREG_REG (x)),
2206 SUBREG_BYTE (x),
2207 GET_MODE (x));
2209 else
2210 i = REGNO (x);
2212 if (GET_CODE (y) == SUBREG)
2214 j = REGNO (SUBREG_REG (y));
2215 if (j >= FIRST_PSEUDO_REGISTER)
2216 goto slow;
2217 j += subreg_regno_offset (REGNO (SUBREG_REG (y)),
2218 GET_MODE (SUBREG_REG (y)),
2219 SUBREG_BYTE (y),
2220 GET_MODE (y));
2222 else
2223 j = REGNO (y);
2225 /* On a REG_WORDS_BIG_ENDIAN machine, point to the last register of a
2226 multiple hard register group of scalar integer registers, so that
2227 for example (reg:DI 0) and (reg:SI 1) will be considered the same
2228 register. */
2229 scalar_int_mode xmode;
2230 if (REG_WORDS_BIG_ENDIAN
2231 && is_a <scalar_int_mode> (GET_MODE (x), &xmode)
2232 && GET_MODE_SIZE (xmode) > UNITS_PER_WORD
2233 && i < FIRST_PSEUDO_REGISTER)
2234 i += hard_regno_nregs (i, xmode) - 1;
2235 scalar_int_mode ymode;
2236 if (REG_WORDS_BIG_ENDIAN
2237 && is_a <scalar_int_mode> (GET_MODE (y), &ymode)
2238 && GET_MODE_SIZE (ymode) > UNITS_PER_WORD
2239 && j < FIRST_PSEUDO_REGISTER)
2240 j += hard_regno_nregs (j, ymode) - 1;
2242 return i == j;
2244 /* If two operands must match, because they are really a single
2245 operand of an assembler insn, then two postincrements are invalid
2246 because the assembler insn would increment only once.
2247 On the other hand, a postincrement matches ordinary indexing
2248 if the postincrement is the output operand. */
2249 if (code == POST_DEC || code == POST_INC || code == POST_MODIFY)
2250 return operands_match_p (XEXP (x, 0), y);
2251 /* Two preincrements are invalid
2252 because the assembler insn would increment only once.
2253 On the other hand, a preincrement matches ordinary indexing
2254 if the preincrement is the input operand.
2255 In this case, return 2, since some callers need to do special
2256 things when this happens. */
2257 if (GET_CODE (y) == PRE_DEC || GET_CODE (y) == PRE_INC
2258 || GET_CODE (y) == PRE_MODIFY)
2259 return operands_match_p (x, XEXP (y, 0)) ? 2 : 0;
2261 slow:
2263 /* Now we have disposed of all the cases in which different rtx codes
2264 can match. */
2265 if (code != GET_CODE (y))
2266 return 0;
2268 /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent. */
2269 if (GET_MODE (x) != GET_MODE (y))
2270 return 0;
2272 /* MEMs referring to different address space are not equivalent. */
2273 if (code == MEM && MEM_ADDR_SPACE (x) != MEM_ADDR_SPACE (y))
2274 return 0;
2276 switch (code)
2278 CASE_CONST_UNIQUE:
2279 return 0;
2281 case LABEL_REF:
2282 return label_ref_label (x) == label_ref_label (y);
2283 case SYMBOL_REF:
2284 return XSTR (x, 0) == XSTR (y, 0);
2286 default:
2287 break;
2290 /* Compare the elements. If any pair of corresponding elements
2291 fail to match, return 0 for the whole things. */
2293 success_2 = 0;
2294 fmt = GET_RTX_FORMAT (code);
2295 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2297 int val, j;
2298 switch (fmt[i])
2300 case 'w':
2301 if (XWINT (x, i) != XWINT (y, i))
2302 return 0;
2303 break;
2305 case 'i':
2306 if (XINT (x, i) != XINT (y, i))
2307 return 0;
2308 break;
2310 case 'p':
2311 if (maybe_ne (SUBREG_BYTE (x), SUBREG_BYTE (y)))
2312 return 0;
2313 break;
2315 case 'e':
2316 val = operands_match_p (XEXP (x, i), XEXP (y, i));
2317 if (val == 0)
2318 return 0;
2319 /* If any subexpression returns 2,
2320 we should return 2 if we are successful. */
2321 if (val == 2)
2322 success_2 = 1;
2323 break;
2325 case '0':
2326 break;
2328 case 'E':
2329 if (XVECLEN (x, i) != XVECLEN (y, i))
2330 return 0;
2331 for (j = XVECLEN (x, i) - 1; j >= 0; --j)
2333 val = operands_match_p (XVECEXP (x, i, j), XVECEXP (y, i, j));
2334 if (val == 0)
2335 return 0;
2336 if (val == 2)
2337 success_2 = 1;
2339 break;
2341 /* It is believed that rtx's at this level will never
2342 contain anything but integers and other rtx's,
2343 except for within LABEL_REFs and SYMBOL_REFs. */
2344 default:
2345 gcc_unreachable ();
2348 return 1 + success_2;
2351 /* Describe the range of registers or memory referenced by X.
2352 If X is a register, set REG_FLAG and put the first register
2353 number into START and the last plus one into END.
2354 If X is a memory reference, put a base address into BASE
2355 and a range of integer offsets into START and END.
2356 If X is pushing on the stack, we can assume it causes no trouble,
2357 so we set the SAFE field. */
2359 static struct decomposition
2360 decompose (rtx x)
2362 struct decomposition val;
2363 int all_const = 0, regno;
2365 memset (&val, 0, sizeof (val));
2367 switch (GET_CODE (x))
2369 case MEM:
2371 rtx base = NULL_RTX, offset = 0;
2372 rtx addr = XEXP (x, 0);
2374 if (GET_CODE (addr) == PRE_DEC || GET_CODE (addr) == PRE_INC
2375 || GET_CODE (addr) == POST_DEC || GET_CODE (addr) == POST_INC)
2377 val.base = XEXP (addr, 0);
2378 val.start = -GET_MODE_SIZE (GET_MODE (x));
2379 val.end = GET_MODE_SIZE (GET_MODE (x));
2380 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2381 return val;
2384 if (GET_CODE (addr) == PRE_MODIFY || GET_CODE (addr) == POST_MODIFY)
2386 if (GET_CODE (XEXP (addr, 1)) == PLUS
2387 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
2388 && CONSTANT_P (XEXP (XEXP (addr, 1), 1)))
2390 val.base = XEXP (addr, 0);
2391 val.start = -INTVAL (XEXP (XEXP (addr, 1), 1));
2392 val.end = INTVAL (XEXP (XEXP (addr, 1), 1));
2393 val.safe = REGNO (val.base) == STACK_POINTER_REGNUM;
2394 return val;
2398 if (GET_CODE (addr) == CONST)
2400 addr = XEXP (addr, 0);
2401 all_const = 1;
2403 if (GET_CODE (addr) == PLUS)
2405 if (CONSTANT_P (XEXP (addr, 0)))
2407 base = XEXP (addr, 1);
2408 offset = XEXP (addr, 0);
2410 else if (CONSTANT_P (XEXP (addr, 1)))
2412 base = XEXP (addr, 0);
2413 offset = XEXP (addr, 1);
2417 if (offset == 0)
2419 base = addr;
2420 offset = const0_rtx;
2422 if (GET_CODE (offset) == CONST)
2423 offset = XEXP (offset, 0);
2424 if (GET_CODE (offset) == PLUS)
2426 if (CONST_INT_P (XEXP (offset, 0)))
2428 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 1));
2429 offset = XEXP (offset, 0);
2431 else if (CONST_INT_P (XEXP (offset, 1)))
2433 base = gen_rtx_PLUS (GET_MODE (base), base, XEXP (offset, 0));
2434 offset = XEXP (offset, 1);
2436 else
2438 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2439 offset = const0_rtx;
2442 else if (!CONST_INT_P (offset))
2444 base = gen_rtx_PLUS (GET_MODE (base), base, offset);
2445 offset = const0_rtx;
2448 if (all_const && GET_CODE (base) == PLUS)
2449 base = gen_rtx_CONST (GET_MODE (base), base);
2451 gcc_assert (CONST_INT_P (offset));
2453 val.start = INTVAL (offset);
2454 val.end = val.start + GET_MODE_SIZE (GET_MODE (x));
2455 val.base = base;
2457 break;
2459 case REG:
2460 val.reg_flag = 1;
2461 regno = true_regnum (x);
2462 if (regno < 0 || regno >= FIRST_PSEUDO_REGISTER)
2464 /* A pseudo with no hard reg. */
2465 val.start = REGNO (x);
2466 val.end = val.start + 1;
2468 else
2470 /* A hard reg. */
2471 val.start = regno;
2472 val.end = end_hard_regno (GET_MODE (x), regno);
2474 break;
2476 case SUBREG:
2477 if (!REG_P (SUBREG_REG (x)))
2478 /* This could be more precise, but it's good enough. */
2479 return decompose (SUBREG_REG (x));
2480 regno = true_regnum (x);
2481 if (regno < 0 || regno >= FIRST_PSEUDO_REGISTER)
2482 return decompose (SUBREG_REG (x));
2484 /* A hard reg. */
2485 val.reg_flag = 1;
2486 val.start = regno;
2487 val.end = regno + subreg_nregs (x);
2488 break;
2490 case SCRATCH:
2491 /* This hasn't been assigned yet, so it can't conflict yet. */
2492 val.safe = 1;
2493 break;
2495 default:
2496 gcc_assert (CONSTANT_P (x));
2497 val.safe = 1;
2498 break;
2500 return val;
2503 /* Return 1 if altering Y will not modify the value of X.
2504 Y is also described by YDATA, which should be decompose (Y). */
2506 static int
2507 immune_p (rtx x, rtx y, struct decomposition ydata)
2509 struct decomposition xdata;
2511 if (ydata.reg_flag)
2512 /* In this case the decomposition structure contains register
2513 numbers rather than byte offsets. */
2514 return !refers_to_regno_for_reload_p (ydata.start.to_constant (),
2515 ydata.end.to_constant (),
2516 x, (rtx *) 0);
2517 if (ydata.safe)
2518 return 1;
2520 gcc_assert (MEM_P (y));
2521 /* If Y is memory and X is not, Y can't affect X. */
2522 if (!MEM_P (x))
2523 return 1;
2525 xdata = decompose (x);
2527 if (! rtx_equal_p (xdata.base, ydata.base))
2529 /* If bases are distinct symbolic constants, there is no overlap. */
2530 if (CONSTANT_P (xdata.base) && CONSTANT_P (ydata.base))
2531 return 1;
2532 /* Constants and stack slots never overlap. */
2533 if (CONSTANT_P (xdata.base)
2534 && (ydata.base == frame_pointer_rtx
2535 || ydata.base == hard_frame_pointer_rtx
2536 || ydata.base == stack_pointer_rtx))
2537 return 1;
2538 if (CONSTANT_P (ydata.base)
2539 && (xdata.base == frame_pointer_rtx
2540 || xdata.base == hard_frame_pointer_rtx
2541 || xdata.base == stack_pointer_rtx))
2542 return 1;
2543 /* If either base is variable, we don't know anything. */
2544 return 0;
2547 return known_ge (xdata.start, ydata.end) || known_ge (ydata.start, xdata.end);
2550 /* Similar, but calls decompose. */
2553 safe_from_earlyclobber (rtx op, rtx clobber)
2555 struct decomposition early_data;
2557 early_data = decompose (clobber);
2558 return immune_p (op, clobber, early_data);
2561 /* Main entry point of this file: search the body of INSN
2562 for values that need reloading and record them with push_reload.
2563 REPLACE nonzero means record also where the values occur
2564 so that subst_reloads can be used.
2566 IND_LEVELS says how many levels of indirection are supported by this
2567 machine; a value of zero means that a memory reference is not a valid
2568 memory address.
2570 LIVE_KNOWN says we have valid information about which hard
2571 regs are live at each point in the program; this is true when
2572 we are called from global_alloc but false when stupid register
2573 allocation has been done.
2575 RELOAD_REG_P if nonzero is a vector indexed by hard reg number
2576 which is nonnegative if the reg has been commandeered for reloading into.
2577 It is copied into STATIC_RELOAD_REG_P and referenced from there
2578 by various subroutines.
2580 Return TRUE if some operands need to be changed, because of swapping
2581 commutative operands, reg_equiv_address substitution, or whatever. */
2584 find_reloads (rtx_insn *insn, int replace, int ind_levels, int live_known,
2585 short *reload_reg_p)
2587 int insn_code_number;
2588 int i, j;
2589 int noperands;
2590 /* These start out as the constraints for the insn
2591 and they are chewed up as we consider alternatives. */
2592 const char *constraints[MAX_RECOG_OPERANDS];
2593 /* These are the preferred classes for an operand, or NO_REGS if it isn't
2594 a register. */
2595 enum reg_class preferred_class[MAX_RECOG_OPERANDS];
2596 char pref_or_nothing[MAX_RECOG_OPERANDS];
2597 /* Nonzero for a MEM operand whose entire address needs a reload.
2598 May be -1 to indicate the entire address may or may not need a reload. */
2599 int address_reloaded[MAX_RECOG_OPERANDS];
2600 /* Nonzero for an address operand that needs to be completely reloaded.
2601 May be -1 to indicate the entire operand may or may not need a reload. */
2602 int address_operand_reloaded[MAX_RECOG_OPERANDS];
2603 /* Value of enum reload_type to use for operand. */
2604 enum reload_type operand_type[MAX_RECOG_OPERANDS];
2605 /* Value of enum reload_type to use within address of operand. */
2606 enum reload_type address_type[MAX_RECOG_OPERANDS];
2607 /* Save the usage of each operand. */
2608 enum reload_usage { RELOAD_READ, RELOAD_READ_WRITE, RELOAD_WRITE } modified[MAX_RECOG_OPERANDS];
2609 int no_input_reloads = 0, no_output_reloads = 0;
2610 int n_alternatives;
2611 reg_class_t this_alternative[MAX_RECOG_OPERANDS];
2612 char this_alternative_match_win[MAX_RECOG_OPERANDS];
2613 char this_alternative_win[MAX_RECOG_OPERANDS];
2614 char this_alternative_offmemok[MAX_RECOG_OPERANDS];
2615 char this_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2616 int this_alternative_matches[MAX_RECOG_OPERANDS];
2617 reg_class_t goal_alternative[MAX_RECOG_OPERANDS];
2618 int this_alternative_number;
2619 int goal_alternative_number = 0;
2620 int operand_reloadnum[MAX_RECOG_OPERANDS];
2621 int goal_alternative_matches[MAX_RECOG_OPERANDS];
2622 int goal_alternative_matched[MAX_RECOG_OPERANDS];
2623 char goal_alternative_match_win[MAX_RECOG_OPERANDS];
2624 char goal_alternative_win[MAX_RECOG_OPERANDS];
2625 char goal_alternative_offmemok[MAX_RECOG_OPERANDS];
2626 char goal_alternative_earlyclobber[MAX_RECOG_OPERANDS];
2627 int goal_alternative_swapped;
2628 int best;
2629 int commutative;
2630 char operands_match[MAX_RECOG_OPERANDS][MAX_RECOG_OPERANDS];
2631 rtx substed_operand[MAX_RECOG_OPERANDS];
2632 rtx body = PATTERN (insn);
2633 rtx set = single_set (insn);
2634 int goal_earlyclobber = 0, this_earlyclobber;
2635 machine_mode operand_mode[MAX_RECOG_OPERANDS];
2636 int retval = 0;
2638 this_insn = insn;
2639 n_reloads = 0;
2640 n_replacements = 0;
2641 n_earlyclobbers = 0;
2642 replace_reloads = replace;
2643 hard_regs_live_known = live_known;
2644 static_reload_reg_p = reload_reg_p;
2646 /* JUMP_INSNs and CALL_INSNs are not allowed to have any output reloads;
2647 neither are insns that SET cc0. Insns that use CC0 are not allowed
2648 to have any input reloads. */
2649 if (JUMP_P (insn) || CALL_P (insn))
2650 no_output_reloads = 1;
2652 if (HAVE_cc0 && reg_referenced_p (cc0_rtx, PATTERN (insn)))
2653 no_input_reloads = 1;
2654 if (HAVE_cc0 && reg_set_p (cc0_rtx, PATTERN (insn)))
2655 no_output_reloads = 1;
2657 /* The eliminated forms of any secondary memory locations are per-insn, so
2658 clear them out here. */
2660 if (secondary_memlocs_elim_used)
2662 memset (secondary_memlocs_elim, 0,
2663 sizeof (secondary_memlocs_elim[0]) * secondary_memlocs_elim_used);
2664 secondary_memlocs_elim_used = 0;
2667 /* Dispose quickly of (set (reg..) (reg..)) if both have hard regs and it
2668 is cheap to move between them. If it is not, there may not be an insn
2669 to do the copy, so we may need a reload. */
2670 if (GET_CODE (body) == SET
2671 && REG_P (SET_DEST (body))
2672 && REGNO (SET_DEST (body)) < FIRST_PSEUDO_REGISTER
2673 && REG_P (SET_SRC (body))
2674 && REGNO (SET_SRC (body)) < FIRST_PSEUDO_REGISTER
2675 && register_move_cost (GET_MODE (SET_SRC (body)),
2676 REGNO_REG_CLASS (REGNO (SET_SRC (body))),
2677 REGNO_REG_CLASS (REGNO (SET_DEST (body)))) == 2)
2678 return 0;
2680 extract_insn (insn);
2682 noperands = reload_n_operands = recog_data.n_operands;
2683 n_alternatives = recog_data.n_alternatives;
2685 /* Just return "no reloads" if insn has no operands with constraints. */
2686 if (noperands == 0 || n_alternatives == 0)
2687 return 0;
2689 insn_code_number = INSN_CODE (insn);
2690 this_insn_is_asm = insn_code_number < 0;
2692 memcpy (operand_mode, recog_data.operand_mode,
2693 noperands * sizeof (machine_mode));
2694 memcpy (constraints, recog_data.constraints,
2695 noperands * sizeof (const char *));
2697 commutative = -1;
2699 /* If we will need to know, later, whether some pair of operands
2700 are the same, we must compare them now and save the result.
2701 Reloading the base and index registers will clobber them
2702 and afterward they will fail to match. */
2704 for (i = 0; i < noperands; i++)
2706 const char *p;
2707 int c;
2708 char *end;
2710 substed_operand[i] = recog_data.operand[i];
2711 p = constraints[i];
2713 modified[i] = RELOAD_READ;
2715 /* Scan this operand's constraint to see if it is an output operand,
2716 an in-out operand, is commutative, or should match another. */
2718 while ((c = *p))
2720 p += CONSTRAINT_LEN (c, p);
2721 switch (c)
2723 case '=':
2724 modified[i] = RELOAD_WRITE;
2725 break;
2726 case '+':
2727 modified[i] = RELOAD_READ_WRITE;
2728 break;
2729 case '%':
2731 /* The last operand should not be marked commutative. */
2732 gcc_assert (i != noperands - 1);
2734 /* We currently only support one commutative pair of
2735 operands. Some existing asm code currently uses more
2736 than one pair. Previously, that would usually work,
2737 but sometimes it would crash the compiler. We
2738 continue supporting that case as well as we can by
2739 silently ignoring all but the first pair. In the
2740 future we may handle it correctly. */
2741 if (commutative < 0)
2742 commutative = i;
2743 else
2744 gcc_assert (this_insn_is_asm);
2746 break;
2747 /* Use of ISDIGIT is tempting here, but it may get expensive because
2748 of locale support we don't want. */
2749 case '0': case '1': case '2': case '3': case '4':
2750 case '5': case '6': case '7': case '8': case '9':
2752 c = strtoul (p - 1, &end, 10);
2753 p = end;
2755 operands_match[c][i]
2756 = operands_match_p (recog_data.operand[c],
2757 recog_data.operand[i]);
2759 /* An operand may not match itself. */
2760 gcc_assert (c != i);
2762 /* If C can be commuted with C+1, and C might need to match I,
2763 then C+1 might also need to match I. */
2764 if (commutative >= 0)
2766 if (c == commutative || c == commutative + 1)
2768 int other = c + (c == commutative ? 1 : -1);
2769 operands_match[other][i]
2770 = operands_match_p (recog_data.operand[other],
2771 recog_data.operand[i]);
2773 if (i == commutative || i == commutative + 1)
2775 int other = i + (i == commutative ? 1 : -1);
2776 operands_match[c][other]
2777 = operands_match_p (recog_data.operand[c],
2778 recog_data.operand[other]);
2780 /* Note that C is supposed to be less than I.
2781 No need to consider altering both C and I because in
2782 that case we would alter one into the other. */
2789 /* Examine each operand that is a memory reference or memory address
2790 and reload parts of the addresses into index registers.
2791 Also here any references to pseudo regs that didn't get hard regs
2792 but are equivalent to constants get replaced in the insn itself
2793 with those constants. Nobody will ever see them again.
2795 Finally, set up the preferred classes of each operand. */
2797 for (i = 0; i < noperands; i++)
2799 RTX_CODE code = GET_CODE (recog_data.operand[i]);
2801 address_reloaded[i] = 0;
2802 address_operand_reloaded[i] = 0;
2803 operand_type[i] = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT
2804 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT
2805 : RELOAD_OTHER);
2806 address_type[i]
2807 = (modified[i] == RELOAD_READ ? RELOAD_FOR_INPUT_ADDRESS
2808 : modified[i] == RELOAD_WRITE ? RELOAD_FOR_OUTPUT_ADDRESS
2809 : RELOAD_OTHER);
2811 if (*constraints[i] == 0)
2812 /* Ignore things like match_operator operands. */
2814 else if (insn_extra_address_constraint
2815 (lookup_constraint (constraints[i])))
2817 address_operand_reloaded[i]
2818 = find_reloads_address (recog_data.operand_mode[i], (rtx*) 0,
2819 recog_data.operand[i],
2820 recog_data.operand_loc[i],
2821 i, operand_type[i], ind_levels, insn);
2823 /* If we now have a simple operand where we used to have a
2824 PLUS or MULT, re-recognize and try again. */
2825 if ((OBJECT_P (*recog_data.operand_loc[i])
2826 || GET_CODE (*recog_data.operand_loc[i]) == SUBREG)
2827 && (GET_CODE (recog_data.operand[i]) == MULT
2828 || GET_CODE (recog_data.operand[i]) == PLUS))
2830 INSN_CODE (insn) = -1;
2831 retval = find_reloads (insn, replace, ind_levels, live_known,
2832 reload_reg_p);
2833 return retval;
2836 recog_data.operand[i] = *recog_data.operand_loc[i];
2837 substed_operand[i] = recog_data.operand[i];
2839 /* Address operands are reloaded in their existing mode,
2840 no matter what is specified in the machine description. */
2841 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2843 /* If the address is a single CONST_INT pick address mode
2844 instead otherwise we will later not know in which mode
2845 the reload should be performed. */
2846 if (operand_mode[i] == VOIDmode)
2847 operand_mode[i] = Pmode;
2850 else if (code == MEM)
2852 address_reloaded[i]
2853 = find_reloads_address (GET_MODE (recog_data.operand[i]),
2854 recog_data.operand_loc[i],
2855 XEXP (recog_data.operand[i], 0),
2856 &XEXP (recog_data.operand[i], 0),
2857 i, address_type[i], ind_levels, insn);
2858 recog_data.operand[i] = *recog_data.operand_loc[i];
2859 substed_operand[i] = recog_data.operand[i];
2861 else if (code == SUBREG)
2863 rtx reg = SUBREG_REG (recog_data.operand[i]);
2864 rtx op
2865 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2866 ind_levels,
2867 set != 0
2868 && &SET_DEST (set) == recog_data.operand_loc[i],
2869 insn,
2870 &address_reloaded[i]);
2872 /* If we made a MEM to load (a part of) the stackslot of a pseudo
2873 that didn't get a hard register, emit a USE with a REG_EQUAL
2874 note in front so that we might inherit a previous, possibly
2875 wider reload. */
2877 if (replace
2878 && MEM_P (op)
2879 && REG_P (reg)
2880 && (GET_MODE_SIZE (GET_MODE (reg))
2881 >= GET_MODE_SIZE (GET_MODE (op)))
2882 && reg_equiv_constant (REGNO (reg)) == 0)
2883 set_unique_reg_note (emit_insn_before (gen_rtx_USE (VOIDmode, reg),
2884 insn),
2885 REG_EQUAL, reg_equiv_memory_loc (REGNO (reg)));
2887 substed_operand[i] = recog_data.operand[i] = op;
2889 else if (code == PLUS || GET_RTX_CLASS (code) == RTX_UNARY)
2890 /* We can get a PLUS as an "operand" as a result of register
2891 elimination. See eliminate_regs and gen_reload. We handle
2892 a unary operator by reloading the operand. */
2893 substed_operand[i] = recog_data.operand[i]
2894 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2895 ind_levels, 0, insn,
2896 &address_reloaded[i]);
2897 else if (code == REG)
2899 /* This is equivalent to calling find_reloads_toplev.
2900 The code is duplicated for speed.
2901 When we find a pseudo always equivalent to a constant,
2902 we replace it by the constant. We must be sure, however,
2903 that we don't try to replace it in the insn in which it
2904 is being set. */
2905 int regno = REGNO (recog_data.operand[i]);
2906 if (reg_equiv_constant (regno) != 0
2907 && (set == 0 || &SET_DEST (set) != recog_data.operand_loc[i]))
2909 /* Record the existing mode so that the check if constants are
2910 allowed will work when operand_mode isn't specified. */
2912 if (operand_mode[i] == VOIDmode)
2913 operand_mode[i] = GET_MODE (recog_data.operand[i]);
2915 substed_operand[i] = recog_data.operand[i]
2916 = reg_equiv_constant (regno);
2918 if (reg_equiv_memory_loc (regno) != 0
2919 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
2920 /* We need not give a valid is_set_dest argument since the case
2921 of a constant equivalence was checked above. */
2922 substed_operand[i] = recog_data.operand[i]
2923 = find_reloads_toplev (recog_data.operand[i], i, address_type[i],
2924 ind_levels, 0, insn,
2925 &address_reloaded[i]);
2927 /* If the operand is still a register (we didn't replace it with an
2928 equivalent), get the preferred class to reload it into. */
2929 code = GET_CODE (recog_data.operand[i]);
2930 preferred_class[i]
2931 = ((code == REG && REGNO (recog_data.operand[i])
2932 >= FIRST_PSEUDO_REGISTER)
2933 ? reg_preferred_class (REGNO (recog_data.operand[i]))
2934 : NO_REGS);
2935 pref_or_nothing[i]
2936 = (code == REG
2937 && REGNO (recog_data.operand[i]) >= FIRST_PSEUDO_REGISTER
2938 && reg_alternate_class (REGNO (recog_data.operand[i])) == NO_REGS);
2941 /* If this is simply a copy from operand 1 to operand 0, merge the
2942 preferred classes for the operands. */
2943 if (set != 0 && noperands >= 2 && recog_data.operand[0] == SET_DEST (set)
2944 && recog_data.operand[1] == SET_SRC (set))
2946 preferred_class[0] = preferred_class[1]
2947 = reg_class_subunion[(int) preferred_class[0]][(int) preferred_class[1]];
2948 pref_or_nothing[0] |= pref_or_nothing[1];
2949 pref_or_nothing[1] |= pref_or_nothing[0];
2952 /* Now see what we need for pseudo-regs that didn't get hard regs
2953 or got the wrong kind of hard reg. For this, we must consider
2954 all the operands together against the register constraints. */
2956 best = MAX_RECOG_OPERANDS * 2 + 600;
2958 goal_alternative_swapped = 0;
2960 /* The constraints are made of several alternatives.
2961 Each operand's constraint looks like foo,bar,... with commas
2962 separating the alternatives. The first alternatives for all
2963 operands go together, the second alternatives go together, etc.
2965 First loop over alternatives. */
2967 alternative_mask enabled = get_enabled_alternatives (insn);
2968 for (this_alternative_number = 0;
2969 this_alternative_number < n_alternatives;
2970 this_alternative_number++)
2972 int swapped;
2974 if (!TEST_BIT (enabled, this_alternative_number))
2976 int i;
2978 for (i = 0; i < recog_data.n_operands; i++)
2979 constraints[i] = skip_alternative (constraints[i]);
2981 continue;
2984 /* If insn is commutative (it's safe to exchange a certain pair
2985 of operands) then we need to try each alternative twice, the
2986 second time matching those two operands as if we had
2987 exchanged them. To do this, really exchange them in
2988 operands. */
2989 for (swapped = 0; swapped < (commutative >= 0 ? 2 : 1); swapped++)
2991 /* Loop over operands for one constraint alternative. */
2992 /* LOSERS counts those that don't fit this alternative
2993 and would require loading. */
2994 int losers = 0;
2995 /* BAD is set to 1 if it some operand can't fit this alternative
2996 even after reloading. */
2997 int bad = 0;
2998 /* REJECT is a count of how undesirable this alternative says it is
2999 if any reloading is required. If the alternative matches exactly
3000 then REJECT is ignored, but otherwise it gets this much
3001 counted against it in addition to the reloading needed. Each
3002 ? counts three times here since we want the disparaging caused by
3003 a bad register class to only count 1/3 as much. */
3004 int reject = 0;
3006 if (swapped)
3008 recog_data.operand[commutative] = substed_operand[commutative + 1];
3009 recog_data.operand[commutative + 1] = substed_operand[commutative];
3010 /* Swap the duplicates too. */
3011 for (i = 0; i < recog_data.n_dups; i++)
3012 if (recog_data.dup_num[i] == commutative
3013 || recog_data.dup_num[i] == commutative + 1)
3014 *recog_data.dup_loc[i]
3015 = recog_data.operand[(int) recog_data.dup_num[i]];
3017 std::swap (preferred_class[commutative],
3018 preferred_class[commutative + 1]);
3019 std::swap (pref_or_nothing[commutative],
3020 pref_or_nothing[commutative + 1]);
3021 std::swap (address_reloaded[commutative],
3022 address_reloaded[commutative + 1]);
3025 this_earlyclobber = 0;
3027 for (i = 0; i < noperands; i++)
3029 const char *p = constraints[i];
3030 char *end;
3031 int len;
3032 int win = 0;
3033 int did_match = 0;
3034 /* 0 => this operand can be reloaded somehow for this alternative. */
3035 int badop = 1;
3036 /* 0 => this operand can be reloaded if the alternative allows regs. */
3037 int winreg = 0;
3038 int c;
3039 int m;
3040 rtx operand = recog_data.operand[i];
3041 int offset = 0;
3042 /* Nonzero means this is a MEM that must be reloaded into a reg
3043 regardless of what the constraint says. */
3044 int force_reload = 0;
3045 int offmemok = 0;
3046 /* Nonzero if a constant forced into memory would be OK for this
3047 operand. */
3048 int constmemok = 0;
3049 int earlyclobber = 0;
3050 enum constraint_num cn;
3051 enum reg_class cl;
3053 /* If the predicate accepts a unary operator, it means that
3054 we need to reload the operand, but do not do this for
3055 match_operator and friends. */
3056 if (UNARY_P (operand) && *p != 0)
3057 operand = XEXP (operand, 0);
3059 /* If the operand is a SUBREG, extract
3060 the REG or MEM (or maybe even a constant) within.
3061 (Constants can occur as a result of reg_equiv_constant.) */
3063 while (GET_CODE (operand) == SUBREG)
3065 /* Offset only matters when operand is a REG and
3066 it is a hard reg. This is because it is passed
3067 to reg_fits_class_p if it is a REG and all pseudos
3068 return 0 from that function. */
3069 if (REG_P (SUBREG_REG (operand))
3070 && REGNO (SUBREG_REG (operand)) < FIRST_PSEUDO_REGISTER)
3072 if (simplify_subreg_regno (REGNO (SUBREG_REG (operand)),
3073 GET_MODE (SUBREG_REG (operand)),
3074 SUBREG_BYTE (operand),
3075 GET_MODE (operand)) < 0)
3076 force_reload = 1;
3077 offset += subreg_regno_offset (REGNO (SUBREG_REG (operand)),
3078 GET_MODE (SUBREG_REG (operand)),
3079 SUBREG_BYTE (operand),
3080 GET_MODE (operand));
3082 operand = SUBREG_REG (operand);
3083 /* Force reload if this is a constant or PLUS or if there may
3084 be a problem accessing OPERAND in the outer mode. */
3085 scalar_int_mode inner_mode;
3086 if (CONSTANT_P (operand)
3087 || GET_CODE (operand) == PLUS
3088 /* We must force a reload of paradoxical SUBREGs
3089 of a MEM because the alignment of the inner value
3090 may not be enough to do the outer reference. On
3091 big-endian machines, it may also reference outside
3092 the object.
3094 On machines that extend byte operations and we have a
3095 SUBREG where both the inner and outer modes are no wider
3096 than a word and the inner mode is narrower, is integral,
3097 and gets extended when loaded from memory, combine.c has
3098 made assumptions about the behavior of the machine in such
3099 register access. If the data is, in fact, in memory we
3100 must always load using the size assumed to be in the
3101 register and let the insn do the different-sized
3102 accesses.
3104 This is doubly true if WORD_REGISTER_OPERATIONS. In
3105 this case eliminate_regs has left non-paradoxical
3106 subregs for push_reload to see. Make sure it does
3107 by forcing the reload.
3109 ??? When is it right at this stage to have a subreg
3110 of a mem that is _not_ to be handled specially? IMO
3111 those should have been reduced to just a mem. */
3112 || ((MEM_P (operand)
3113 || (REG_P (operand)
3114 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
3115 && (WORD_REGISTER_OPERATIONS
3116 || ((GET_MODE_BITSIZE (GET_MODE (operand))
3117 < BIGGEST_ALIGNMENT)
3118 && paradoxical_subreg_p (operand_mode[i],
3119 GET_MODE (operand)))
3120 || BYTES_BIG_ENDIAN
3121 || ((GET_MODE_SIZE (operand_mode[i])
3122 <= UNITS_PER_WORD)
3123 && (is_a <scalar_int_mode>
3124 (GET_MODE (operand), &inner_mode))
3125 && (GET_MODE_SIZE (inner_mode)
3126 <= UNITS_PER_WORD)
3127 && paradoxical_subreg_p (operand_mode[i],
3128 inner_mode)
3129 && LOAD_EXTEND_OP (inner_mode) != UNKNOWN)))
3131 force_reload = 1;
3134 this_alternative[i] = NO_REGS;
3135 this_alternative_win[i] = 0;
3136 this_alternative_match_win[i] = 0;
3137 this_alternative_offmemok[i] = 0;
3138 this_alternative_earlyclobber[i] = 0;
3139 this_alternative_matches[i] = -1;
3141 /* An empty constraint or empty alternative
3142 allows anything which matched the pattern. */
3143 if (*p == 0 || *p == ',')
3144 win = 1, badop = 0;
3146 /* Scan this alternative's specs for this operand;
3147 set WIN if the operand fits any letter in this alternative.
3148 Otherwise, clear BADOP if this operand could
3149 fit some letter after reloads,
3150 or set WINREG if this operand could fit after reloads
3151 provided the constraint allows some registers. */
3154 switch ((c = *p, len = CONSTRAINT_LEN (c, p)), c)
3156 case '\0':
3157 len = 0;
3158 break;
3159 case ',':
3160 c = '\0';
3161 break;
3163 case '?':
3164 reject += 6;
3165 break;
3167 case '!':
3168 reject = 600;
3169 break;
3171 case '#':
3172 /* Ignore rest of this alternative as far as
3173 reloading is concerned. */
3175 p++;
3176 while (*p && *p != ',');
3177 len = 0;
3178 break;
3180 case '0': case '1': case '2': case '3': case '4':
3181 case '5': case '6': case '7': case '8': case '9':
3182 m = strtoul (p, &end, 10);
3183 p = end;
3184 len = 0;
3186 this_alternative_matches[i] = m;
3187 /* We are supposed to match a previous operand.
3188 If we do, we win if that one did.
3189 If we do not, count both of the operands as losers.
3190 (This is too conservative, since most of the time
3191 only a single reload insn will be needed to make
3192 the two operands win. As a result, this alternative
3193 may be rejected when it is actually desirable.) */
3194 if ((swapped && (m != commutative || i != commutative + 1))
3195 /* If we are matching as if two operands were swapped,
3196 also pretend that operands_match had been computed
3197 with swapped.
3198 But if I is the second of those and C is the first,
3199 don't exchange them, because operands_match is valid
3200 only on one side of its diagonal. */
3201 ? (operands_match
3202 [(m == commutative || m == commutative + 1)
3203 ? 2 * commutative + 1 - m : m]
3204 [(i == commutative || i == commutative + 1)
3205 ? 2 * commutative + 1 - i : i])
3206 : operands_match[m][i])
3208 /* If we are matching a non-offsettable address where an
3209 offsettable address was expected, then we must reject
3210 this combination, because we can't reload it. */
3211 if (this_alternative_offmemok[m]
3212 && MEM_P (recog_data.operand[m])
3213 && this_alternative[m] == NO_REGS
3214 && ! this_alternative_win[m])
3215 bad = 1;
3217 did_match = this_alternative_win[m];
3219 else
3221 /* Operands don't match. */
3222 rtx value;
3223 int loc1, loc2;
3224 /* Retroactively mark the operand we had to match
3225 as a loser, if it wasn't already. */
3226 if (this_alternative_win[m])
3227 losers++;
3228 this_alternative_win[m] = 0;
3229 if (this_alternative[m] == NO_REGS)
3230 bad = 1;
3231 /* But count the pair only once in the total badness of
3232 this alternative, if the pair can be a dummy reload.
3233 The pointers in operand_loc are not swapped; swap
3234 them by hand if necessary. */
3235 if (swapped && i == commutative)
3236 loc1 = commutative + 1;
3237 else if (swapped && i == commutative + 1)
3238 loc1 = commutative;
3239 else
3240 loc1 = i;
3241 if (swapped && m == commutative)
3242 loc2 = commutative + 1;
3243 else if (swapped && m == commutative + 1)
3244 loc2 = commutative;
3245 else
3246 loc2 = m;
3247 value
3248 = find_dummy_reload (recog_data.operand[i],
3249 recog_data.operand[m],
3250 recog_data.operand_loc[loc1],
3251 recog_data.operand_loc[loc2],
3252 operand_mode[i], operand_mode[m],
3253 this_alternative[m], -1,
3254 this_alternative_earlyclobber[m]);
3256 if (value != 0)
3257 losers--;
3259 /* This can be fixed with reloads if the operand
3260 we are supposed to match can be fixed with reloads. */
3261 badop = 0;
3262 this_alternative[i] = this_alternative[m];
3264 /* If we have to reload this operand and some previous
3265 operand also had to match the same thing as this
3266 operand, we don't know how to do that. So reject this
3267 alternative. */
3268 if (! did_match || force_reload)
3269 for (j = 0; j < i; j++)
3270 if (this_alternative_matches[j]
3271 == this_alternative_matches[i])
3273 badop = 1;
3274 break;
3276 break;
3278 case 'p':
3279 /* All necessary reloads for an address_operand
3280 were handled in find_reloads_address. */
3281 this_alternative[i]
3282 = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
3283 ADDRESS, SCRATCH);
3284 win = 1;
3285 badop = 0;
3286 break;
3288 case TARGET_MEM_CONSTRAINT:
3289 if (force_reload)
3290 break;
3291 if (MEM_P (operand)
3292 || (REG_P (operand)
3293 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3294 && reg_renumber[REGNO (operand)] < 0))
3295 win = 1;
3296 if (CONST_POOL_OK_P (operand_mode[i], operand))
3297 badop = 0;
3298 constmemok = 1;
3299 break;
3301 case '<':
3302 if (MEM_P (operand)
3303 && ! address_reloaded[i]
3304 && (GET_CODE (XEXP (operand, 0)) == PRE_DEC
3305 || GET_CODE (XEXP (operand, 0)) == POST_DEC))
3306 win = 1;
3307 break;
3309 case '>':
3310 if (MEM_P (operand)
3311 && ! address_reloaded[i]
3312 && (GET_CODE (XEXP (operand, 0)) == PRE_INC
3313 || GET_CODE (XEXP (operand, 0)) == POST_INC))
3314 win = 1;
3315 break;
3317 /* Memory operand whose address is not offsettable. */
3318 case 'V':
3319 if (force_reload)
3320 break;
3321 if (MEM_P (operand)
3322 && ! (ind_levels ? offsettable_memref_p (operand)
3323 : offsettable_nonstrict_memref_p (operand))
3324 /* Certain mem addresses will become offsettable
3325 after they themselves are reloaded. This is important;
3326 we don't want our own handling of unoffsettables
3327 to override the handling of reg_equiv_address. */
3328 && !(REG_P (XEXP (operand, 0))
3329 && (ind_levels == 0
3330 || reg_equiv_address (REGNO (XEXP (operand, 0))) != 0)))
3331 win = 1;
3332 break;
3334 /* Memory operand whose address is offsettable. */
3335 case 'o':
3336 if (force_reload)
3337 break;
3338 if ((MEM_P (operand)
3339 /* If IND_LEVELS, find_reloads_address won't reload a
3340 pseudo that didn't get a hard reg, so we have to
3341 reject that case. */
3342 && ((ind_levels ? offsettable_memref_p (operand)
3343 : offsettable_nonstrict_memref_p (operand))
3344 /* A reloaded address is offsettable because it is now
3345 just a simple register indirect. */
3346 || address_reloaded[i] == 1))
3347 || (REG_P (operand)
3348 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3349 && reg_renumber[REGNO (operand)] < 0
3350 /* If reg_equiv_address is nonzero, we will be
3351 loading it into a register; hence it will be
3352 offsettable, but we cannot say that reg_equiv_mem
3353 is offsettable without checking. */
3354 && ((reg_equiv_mem (REGNO (operand)) != 0
3355 && offsettable_memref_p (reg_equiv_mem (REGNO (operand))))
3356 || (reg_equiv_address (REGNO (operand)) != 0))))
3357 win = 1;
3358 if (CONST_POOL_OK_P (operand_mode[i], operand)
3359 || MEM_P (operand))
3360 badop = 0;
3361 constmemok = 1;
3362 offmemok = 1;
3363 break;
3365 case '&':
3366 /* Output operand that is stored before the need for the
3367 input operands (and their index registers) is over. */
3368 earlyclobber = 1, this_earlyclobber = 1;
3369 break;
3371 case 'X':
3372 force_reload = 0;
3373 win = 1;
3374 break;
3376 case 'g':
3377 if (! force_reload
3378 /* A PLUS is never a valid operand, but reload can make
3379 it from a register when eliminating registers. */
3380 && GET_CODE (operand) != PLUS
3381 /* A SCRATCH is not a valid operand. */
3382 && GET_CODE (operand) != SCRATCH
3383 && (! CONSTANT_P (operand)
3384 || ! flag_pic
3385 || LEGITIMATE_PIC_OPERAND_P (operand))
3386 && (GENERAL_REGS == ALL_REGS
3387 || !REG_P (operand)
3388 || (REGNO (operand) >= FIRST_PSEUDO_REGISTER
3389 && reg_renumber[REGNO (operand)] < 0)))
3390 win = 1;
3391 cl = GENERAL_REGS;
3392 goto reg;
3394 default:
3395 cn = lookup_constraint (p);
3396 switch (get_constraint_type (cn))
3398 case CT_REGISTER:
3399 cl = reg_class_for_constraint (cn);
3400 if (cl != NO_REGS)
3401 goto reg;
3402 break;
3404 case CT_CONST_INT:
3405 if (CONST_INT_P (operand)
3406 && (insn_const_int_ok_for_constraint
3407 (INTVAL (operand), cn)))
3408 win = true;
3409 break;
3411 case CT_MEMORY:
3412 if (force_reload)
3413 break;
3414 if (constraint_satisfied_p (operand, cn))
3415 win = 1;
3416 /* If the address was already reloaded,
3417 we win as well. */
3418 else if (MEM_P (operand) && address_reloaded[i] == 1)
3419 win = 1;
3420 /* Likewise if the address will be reloaded because
3421 reg_equiv_address is nonzero. For reg_equiv_mem
3422 we have to check. */
3423 else if (REG_P (operand)
3424 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3425 && reg_renumber[REGNO (operand)] < 0
3426 && ((reg_equiv_mem (REGNO (operand)) != 0
3427 && (constraint_satisfied_p
3428 (reg_equiv_mem (REGNO (operand)),
3429 cn)))
3430 || (reg_equiv_address (REGNO (operand))
3431 != 0)))
3432 win = 1;
3434 /* If we didn't already win, we can reload
3435 constants via force_const_mem, and other
3436 MEMs by reloading the address like for 'o'. */
3437 if (CONST_POOL_OK_P (operand_mode[i], operand)
3438 || MEM_P (operand))
3439 badop = 0;
3440 constmemok = 1;
3441 offmemok = 1;
3442 break;
3444 case CT_SPECIAL_MEMORY:
3445 if (force_reload)
3446 break;
3447 if (constraint_satisfied_p (operand, cn))
3448 win = 1;
3449 /* Likewise if the address will be reloaded because
3450 reg_equiv_address is nonzero. For reg_equiv_mem
3451 we have to check. */
3452 else if (REG_P (operand)
3453 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
3454 && reg_renumber[REGNO (operand)] < 0
3455 && reg_equiv_mem (REGNO (operand)) != 0
3456 && (constraint_satisfied_p
3457 (reg_equiv_mem (REGNO (operand)), cn)))
3458 win = 1;
3459 break;
3461 case CT_ADDRESS:
3462 if (constraint_satisfied_p (operand, cn))
3463 win = 1;
3465 /* If we didn't already win, we can reload
3466 the address into a base register. */
3467 this_alternative[i]
3468 = base_reg_class (VOIDmode, ADDR_SPACE_GENERIC,
3469 ADDRESS, SCRATCH);
3470 badop = 0;
3471 break;
3473 case CT_FIXED_FORM:
3474 if (constraint_satisfied_p (operand, cn))
3475 win = 1;
3476 break;
3478 break;
3480 reg:
3481 this_alternative[i]
3482 = reg_class_subunion[this_alternative[i]][cl];
3483 if (GET_MODE (operand) == BLKmode)
3484 break;
3485 winreg = 1;
3486 if (REG_P (operand)
3487 && reg_fits_class_p (operand, this_alternative[i],
3488 offset, GET_MODE (recog_data.operand[i])))
3489 win = 1;
3490 break;
3492 while ((p += len), c);
3494 if (swapped == (commutative >= 0 ? 1 : 0))
3495 constraints[i] = p;
3497 /* If this operand could be handled with a reg,
3498 and some reg is allowed, then this operand can be handled. */
3499 if (winreg && this_alternative[i] != NO_REGS
3500 && (win || !class_only_fixed_regs[this_alternative[i]]))
3501 badop = 0;
3503 /* Record which operands fit this alternative. */
3504 this_alternative_earlyclobber[i] = earlyclobber;
3505 if (win && ! force_reload)
3506 this_alternative_win[i] = 1;
3507 else if (did_match && ! force_reload)
3508 this_alternative_match_win[i] = 1;
3509 else
3511 int const_to_mem = 0;
3513 this_alternative_offmemok[i] = offmemok;
3514 losers++;
3515 if (badop)
3516 bad = 1;
3517 /* Alternative loses if it has no regs for a reg operand. */
3518 if (REG_P (operand)
3519 && this_alternative[i] == NO_REGS
3520 && this_alternative_matches[i] < 0)
3521 bad = 1;
3523 /* If this is a constant that is reloaded into the desired
3524 class by copying it to memory first, count that as another
3525 reload. This is consistent with other code and is
3526 required to avoid choosing another alternative when
3527 the constant is moved into memory by this function on
3528 an early reload pass. Note that the test here is
3529 precisely the same as in the code below that calls
3530 force_const_mem. */
3531 if (CONST_POOL_OK_P (operand_mode[i], operand)
3532 && ((targetm.preferred_reload_class (operand,
3533 this_alternative[i])
3534 == NO_REGS)
3535 || no_input_reloads))
3537 const_to_mem = 1;
3538 if (this_alternative[i] != NO_REGS)
3539 losers++;
3542 /* Alternative loses if it requires a type of reload not
3543 permitted for this insn. We can always reload SCRATCH
3544 and objects with a REG_UNUSED note. */
3545 if (GET_CODE (operand) != SCRATCH
3546 && modified[i] != RELOAD_READ && no_output_reloads
3547 && ! find_reg_note (insn, REG_UNUSED, operand))
3548 bad = 1;
3549 else if (modified[i] != RELOAD_WRITE && no_input_reloads
3550 && ! const_to_mem)
3551 bad = 1;
3553 /* If we can't reload this value at all, reject this
3554 alternative. Note that we could also lose due to
3555 LIMIT_RELOAD_CLASS, but we don't check that
3556 here. */
3558 if (! CONSTANT_P (operand) && this_alternative[i] != NO_REGS)
3560 if (targetm.preferred_reload_class (operand,
3561 this_alternative[i])
3562 == NO_REGS)
3563 reject = 600;
3565 if (operand_type[i] == RELOAD_FOR_OUTPUT
3566 && (targetm.preferred_output_reload_class (operand,
3567 this_alternative[i])
3568 == NO_REGS))
3569 reject = 600;
3572 /* We prefer to reload pseudos over reloading other things,
3573 since such reloads may be able to be eliminated later.
3574 If we are reloading a SCRATCH, we won't be generating any
3575 insns, just using a register, so it is also preferred.
3576 So bump REJECT in other cases. Don't do this in the
3577 case where we are forcing a constant into memory and
3578 it will then win since we don't want to have a different
3579 alternative match then. */
3580 if (! (REG_P (operand)
3581 && REGNO (operand) >= FIRST_PSEUDO_REGISTER)
3582 && GET_CODE (operand) != SCRATCH
3583 && ! (const_to_mem && constmemok))
3584 reject += 2;
3586 /* Input reloads can be inherited more often than output
3587 reloads can be removed, so penalize output reloads. */
3588 if (operand_type[i] != RELOAD_FOR_INPUT
3589 && GET_CODE (operand) != SCRATCH)
3590 reject++;
3593 /* If this operand is a pseudo register that didn't get
3594 a hard reg and this alternative accepts some
3595 register, see if the class that we want is a subset
3596 of the preferred class for this register. If not,
3597 but it intersects that class, use the preferred class
3598 instead. If it does not intersect the preferred
3599 class, show that usage of this alternative should be
3600 discouraged; it will be discouraged more still if the
3601 register is `preferred or nothing'. We do this
3602 because it increases the chance of reusing our spill
3603 register in a later insn and avoiding a pair of
3604 memory stores and loads.
3606 Don't bother with this if this alternative will
3607 accept this operand.
3609 Don't do this for a multiword operand, since it is
3610 only a small win and has the risk of requiring more
3611 spill registers, which could cause a large loss.
3613 Don't do this if the preferred class has only one
3614 register because we might otherwise exhaust the
3615 class. */
3617 if (! win && ! did_match
3618 && this_alternative[i] != NO_REGS
3619 && GET_MODE_SIZE (operand_mode[i]) <= UNITS_PER_WORD
3620 && reg_class_size [(int) preferred_class[i]] > 0
3621 && ! small_register_class_p (preferred_class[i]))
3623 if (! reg_class_subset_p (this_alternative[i],
3624 preferred_class[i]))
3626 /* Since we don't have a way of forming the intersection,
3627 we just do something special if the preferred class
3628 is a subset of the class we have; that's the most
3629 common case anyway. */
3630 if (reg_class_subset_p (preferred_class[i],
3631 this_alternative[i]))
3632 this_alternative[i] = preferred_class[i];
3633 else
3634 reject += (2 + 2 * pref_or_nothing[i]);
3639 /* Now see if any output operands that are marked "earlyclobber"
3640 in this alternative conflict with any input operands
3641 or any memory addresses. */
3643 for (i = 0; i < noperands; i++)
3644 if (this_alternative_earlyclobber[i]
3645 && (this_alternative_win[i] || this_alternative_match_win[i]))
3647 struct decomposition early_data;
3649 early_data = decompose (recog_data.operand[i]);
3651 gcc_assert (modified[i] != RELOAD_READ);
3653 if (this_alternative[i] == NO_REGS)
3655 this_alternative_earlyclobber[i] = 0;
3656 gcc_assert (this_insn_is_asm);
3657 error_for_asm (this_insn,
3658 "%<&%> constraint used with no register class");
3661 for (j = 0; j < noperands; j++)
3662 /* Is this an input operand or a memory ref? */
3663 if ((MEM_P (recog_data.operand[j])
3664 || modified[j] != RELOAD_WRITE)
3665 && j != i
3666 /* Ignore things like match_operator operands. */
3667 && !recog_data.is_operator[j]
3668 /* Don't count an input operand that is constrained to match
3669 the early clobber operand. */
3670 && ! (this_alternative_matches[j] == i
3671 && rtx_equal_p (recog_data.operand[i],
3672 recog_data.operand[j]))
3673 /* Is it altered by storing the earlyclobber operand? */
3674 && !immune_p (recog_data.operand[j], recog_data.operand[i],
3675 early_data))
3677 /* If the output is in a non-empty few-regs class,
3678 it's costly to reload it, so reload the input instead. */
3679 if (small_register_class_p (this_alternative[i])
3680 && (REG_P (recog_data.operand[j])
3681 || GET_CODE (recog_data.operand[j]) == SUBREG))
3683 losers++;
3684 this_alternative_win[j] = 0;
3685 this_alternative_match_win[j] = 0;
3687 else
3688 break;
3690 /* If an earlyclobber operand conflicts with something,
3691 it must be reloaded, so request this and count the cost. */
3692 if (j != noperands)
3694 losers++;
3695 this_alternative_win[i] = 0;
3696 this_alternative_match_win[j] = 0;
3697 for (j = 0; j < noperands; j++)
3698 if (this_alternative_matches[j] == i
3699 && this_alternative_match_win[j])
3701 this_alternative_win[j] = 0;
3702 this_alternative_match_win[j] = 0;
3703 losers++;
3708 /* If one alternative accepts all the operands, no reload required,
3709 choose that alternative; don't consider the remaining ones. */
3710 if (losers == 0)
3712 /* Unswap these so that they are never swapped at `finish'. */
3713 if (swapped)
3715 recog_data.operand[commutative] = substed_operand[commutative];
3716 recog_data.operand[commutative + 1]
3717 = substed_operand[commutative + 1];
3719 for (i = 0; i < noperands; i++)
3721 goal_alternative_win[i] = this_alternative_win[i];
3722 goal_alternative_match_win[i] = this_alternative_match_win[i];
3723 goal_alternative[i] = this_alternative[i];
3724 goal_alternative_offmemok[i] = this_alternative_offmemok[i];
3725 goal_alternative_matches[i] = this_alternative_matches[i];
3726 goal_alternative_earlyclobber[i]
3727 = this_alternative_earlyclobber[i];
3729 goal_alternative_number = this_alternative_number;
3730 goal_alternative_swapped = swapped;
3731 goal_earlyclobber = this_earlyclobber;
3732 goto finish;
3735 /* REJECT, set by the ! and ? constraint characters and when a register
3736 would be reloaded into a non-preferred class, discourages the use of
3737 this alternative for a reload goal. REJECT is incremented by six
3738 for each ? and two for each non-preferred class. */
3739 losers = losers * 6 + reject;
3741 /* If this alternative can be made to work by reloading,
3742 and it needs less reloading than the others checked so far,
3743 record it as the chosen goal for reloading. */
3744 if (! bad)
3746 if (best > losers)
3748 for (i = 0; i < noperands; i++)
3750 goal_alternative[i] = this_alternative[i];
3751 goal_alternative_win[i] = this_alternative_win[i];
3752 goal_alternative_match_win[i]
3753 = this_alternative_match_win[i];
3754 goal_alternative_offmemok[i]
3755 = this_alternative_offmemok[i];
3756 goal_alternative_matches[i] = this_alternative_matches[i];
3757 goal_alternative_earlyclobber[i]
3758 = this_alternative_earlyclobber[i];
3760 goal_alternative_swapped = swapped;
3761 best = losers;
3762 goal_alternative_number = this_alternative_number;
3763 goal_earlyclobber = this_earlyclobber;
3767 if (swapped)
3769 /* If the commutative operands have been swapped, swap
3770 them back in order to check the next alternative. */
3771 recog_data.operand[commutative] = substed_operand[commutative];
3772 recog_data.operand[commutative + 1] = substed_operand[commutative + 1];
3773 /* Unswap the duplicates too. */
3774 for (i = 0; i < recog_data.n_dups; i++)
3775 if (recog_data.dup_num[i] == commutative
3776 || recog_data.dup_num[i] == commutative + 1)
3777 *recog_data.dup_loc[i]
3778 = recog_data.operand[(int) recog_data.dup_num[i]];
3780 /* Unswap the operand related information as well. */
3781 std::swap (preferred_class[commutative],
3782 preferred_class[commutative + 1]);
3783 std::swap (pref_or_nothing[commutative],
3784 pref_or_nothing[commutative + 1]);
3785 std::swap (address_reloaded[commutative],
3786 address_reloaded[commutative + 1]);
3791 /* The operands don't meet the constraints.
3792 goal_alternative describes the alternative
3793 that we could reach by reloading the fewest operands.
3794 Reload so as to fit it. */
3796 if (best == MAX_RECOG_OPERANDS * 2 + 600)
3798 /* No alternative works with reloads?? */
3799 if (insn_code_number >= 0)
3800 fatal_insn ("unable to generate reloads for:", insn);
3801 error_for_asm (insn, "inconsistent operand constraints in an %<asm%>");
3802 /* Avoid further trouble with this insn. */
3803 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
3804 n_reloads = 0;
3805 return 0;
3808 /* Jump to `finish' from above if all operands are valid already.
3809 In that case, goal_alternative_win is all 1. */
3810 finish:
3812 /* Right now, for any pair of operands I and J that are required to match,
3813 with I < J,
3814 goal_alternative_matches[J] is I.
3815 Set up goal_alternative_matched as the inverse function:
3816 goal_alternative_matched[I] = J. */
3818 for (i = 0; i < noperands; i++)
3819 goal_alternative_matched[i] = -1;
3821 for (i = 0; i < noperands; i++)
3822 if (! goal_alternative_win[i]
3823 && goal_alternative_matches[i] >= 0)
3824 goal_alternative_matched[goal_alternative_matches[i]] = i;
3826 for (i = 0; i < noperands; i++)
3827 goal_alternative_win[i] |= goal_alternative_match_win[i];
3829 /* If the best alternative is with operands 1 and 2 swapped,
3830 consider them swapped before reporting the reloads. Update the
3831 operand numbers of any reloads already pushed. */
3833 if (goal_alternative_swapped)
3835 std::swap (substed_operand[commutative],
3836 substed_operand[commutative + 1]);
3837 std::swap (recog_data.operand[commutative],
3838 recog_data.operand[commutative + 1]);
3839 std::swap (*recog_data.operand_loc[commutative],
3840 *recog_data.operand_loc[commutative + 1]);
3842 for (i = 0; i < recog_data.n_dups; i++)
3843 if (recog_data.dup_num[i] == commutative
3844 || recog_data.dup_num[i] == commutative + 1)
3845 *recog_data.dup_loc[i]
3846 = recog_data.operand[(int) recog_data.dup_num[i]];
3848 for (i = 0; i < n_reloads; i++)
3850 if (rld[i].opnum == commutative)
3851 rld[i].opnum = commutative + 1;
3852 else if (rld[i].opnum == commutative + 1)
3853 rld[i].opnum = commutative;
3857 for (i = 0; i < noperands; i++)
3859 operand_reloadnum[i] = -1;
3861 /* If this is an earlyclobber operand, we need to widen the scope.
3862 The reload must remain valid from the start of the insn being
3863 reloaded until after the operand is stored into its destination.
3864 We approximate this with RELOAD_OTHER even though we know that we
3865 do not conflict with RELOAD_FOR_INPUT_ADDRESS reloads.
3867 One special case that is worth checking is when we have an
3868 output that is earlyclobber but isn't used past the insn (typically
3869 a SCRATCH). In this case, we only need have the reload live
3870 through the insn itself, but not for any of our input or output
3871 reloads.
3872 But we must not accidentally narrow the scope of an existing
3873 RELOAD_OTHER reload - leave these alone.
3875 In any case, anything needed to address this operand can remain
3876 however they were previously categorized. */
3878 if (goal_alternative_earlyclobber[i] && operand_type[i] != RELOAD_OTHER)
3879 operand_type[i]
3880 = (find_reg_note (insn, REG_UNUSED, recog_data.operand[i])
3881 ? RELOAD_FOR_INSN : RELOAD_OTHER);
3884 /* Any constants that aren't allowed and can't be reloaded
3885 into registers are here changed into memory references. */
3886 for (i = 0; i < noperands; i++)
3887 if (! goal_alternative_win[i])
3889 rtx op = recog_data.operand[i];
3890 rtx subreg = NULL_RTX;
3891 rtx plus = NULL_RTX;
3892 machine_mode mode = operand_mode[i];
3894 /* Reloads of SUBREGs of CONSTANT RTXs are handled later in
3895 push_reload so we have to let them pass here. */
3896 if (GET_CODE (op) == SUBREG)
3898 subreg = op;
3899 op = SUBREG_REG (op);
3900 mode = GET_MODE (op);
3903 if (GET_CODE (op) == PLUS)
3905 plus = op;
3906 op = XEXP (op, 1);
3909 if (CONST_POOL_OK_P (mode, op)
3910 && ((targetm.preferred_reload_class (op, goal_alternative[i])
3911 == NO_REGS)
3912 || no_input_reloads))
3914 int this_address_reloaded;
3915 rtx tem = force_const_mem (mode, op);
3917 /* If we stripped a SUBREG or a PLUS above add it back. */
3918 if (plus != NULL_RTX)
3919 tem = gen_rtx_PLUS (mode, XEXP (plus, 0), tem);
3921 if (subreg != NULL_RTX)
3922 tem = gen_rtx_SUBREG (operand_mode[i], tem, SUBREG_BYTE (subreg));
3924 this_address_reloaded = 0;
3925 substed_operand[i] = recog_data.operand[i]
3926 = find_reloads_toplev (tem, i, address_type[i], ind_levels,
3927 0, insn, &this_address_reloaded);
3929 /* If the alternative accepts constant pool refs directly
3930 there will be no reload needed at all. */
3931 if (plus == NULL_RTX
3932 && subreg == NULL_RTX
3933 && alternative_allows_const_pool_ref (this_address_reloaded != 1
3934 ? substed_operand[i]
3935 : NULL,
3936 recog_data.constraints[i],
3937 goal_alternative_number))
3938 goal_alternative_win[i] = 1;
3942 /* Record the values of the earlyclobber operands for the caller. */
3943 if (goal_earlyclobber)
3944 for (i = 0; i < noperands; i++)
3945 if (goal_alternative_earlyclobber[i])
3946 reload_earlyclobbers[n_earlyclobbers++] = recog_data.operand[i];
3948 /* Now record reloads for all the operands that need them. */
3949 for (i = 0; i < noperands; i++)
3950 if (! goal_alternative_win[i])
3952 /* Operands that match previous ones have already been handled. */
3953 if (goal_alternative_matches[i] >= 0)
3955 /* Handle an operand with a nonoffsettable address
3956 appearing where an offsettable address will do
3957 by reloading the address into a base register.
3959 ??? We can also do this when the operand is a register and
3960 reg_equiv_mem is not offsettable, but this is a bit tricky,
3961 so we don't bother with it. It may not be worth doing. */
3962 else if (goal_alternative_matched[i] == -1
3963 && goal_alternative_offmemok[i]
3964 && MEM_P (recog_data.operand[i]))
3966 /* If the address to be reloaded is a VOIDmode constant,
3967 use the default address mode as mode of the reload register,
3968 as would have been done by find_reloads_address. */
3969 addr_space_t as = MEM_ADDR_SPACE (recog_data.operand[i]);
3970 machine_mode address_mode;
3972 address_mode = get_address_mode (recog_data.operand[i]);
3973 operand_reloadnum[i]
3974 = push_reload (XEXP (recog_data.operand[i], 0), NULL_RTX,
3975 &XEXP (recog_data.operand[i], 0), (rtx*) 0,
3976 base_reg_class (VOIDmode, as, MEM, SCRATCH),
3977 address_mode,
3978 VOIDmode, 0, 0, i, RELOAD_OTHER);
3979 rld[operand_reloadnum[i]].inc
3980 = GET_MODE_SIZE (GET_MODE (recog_data.operand[i]));
3982 /* If this operand is an output, we will have made any
3983 reloads for its address as RELOAD_FOR_OUTPUT_ADDRESS, but
3984 now we are treating part of the operand as an input, so
3985 we must change these to RELOAD_FOR_OTHER_ADDRESS. */
3987 if (modified[i] == RELOAD_WRITE)
3989 for (j = 0; j < n_reloads; j++)
3991 if (rld[j].opnum == i)
3993 if (rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS)
3994 rld[j].when_needed = RELOAD_FOR_OTHER_ADDRESS;
3995 else if (rld[j].when_needed
3996 == RELOAD_FOR_OUTADDR_ADDRESS)
3997 rld[j].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4002 else if (goal_alternative_matched[i] == -1)
4004 operand_reloadnum[i]
4005 = push_reload ((modified[i] != RELOAD_WRITE
4006 ? recog_data.operand[i] : 0),
4007 (modified[i] != RELOAD_READ
4008 ? recog_data.operand[i] : 0),
4009 (modified[i] != RELOAD_WRITE
4010 ? recog_data.operand_loc[i] : 0),
4011 (modified[i] != RELOAD_READ
4012 ? recog_data.operand_loc[i] : 0),
4013 (enum reg_class) goal_alternative[i],
4014 (modified[i] == RELOAD_WRITE
4015 ? VOIDmode : operand_mode[i]),
4016 (modified[i] == RELOAD_READ
4017 ? VOIDmode : operand_mode[i]),
4018 (insn_code_number < 0 ? 0
4019 : insn_data[insn_code_number].operand[i].strict_low),
4020 0, i, operand_type[i]);
4022 /* In a matching pair of operands, one must be input only
4023 and the other must be output only.
4024 Pass the input operand as IN and the other as OUT. */
4025 else if (modified[i] == RELOAD_READ
4026 && modified[goal_alternative_matched[i]] == RELOAD_WRITE)
4028 operand_reloadnum[i]
4029 = push_reload (recog_data.operand[i],
4030 recog_data.operand[goal_alternative_matched[i]],
4031 recog_data.operand_loc[i],
4032 recog_data.operand_loc[goal_alternative_matched[i]],
4033 (enum reg_class) goal_alternative[i],
4034 operand_mode[i],
4035 operand_mode[goal_alternative_matched[i]],
4036 0, 0, i, RELOAD_OTHER);
4037 operand_reloadnum[goal_alternative_matched[i]] = output_reloadnum;
4039 else if (modified[i] == RELOAD_WRITE
4040 && modified[goal_alternative_matched[i]] == RELOAD_READ)
4042 operand_reloadnum[goal_alternative_matched[i]]
4043 = push_reload (recog_data.operand[goal_alternative_matched[i]],
4044 recog_data.operand[i],
4045 recog_data.operand_loc[goal_alternative_matched[i]],
4046 recog_data.operand_loc[i],
4047 (enum reg_class) goal_alternative[i],
4048 operand_mode[goal_alternative_matched[i]],
4049 operand_mode[i],
4050 0, 0, i, RELOAD_OTHER);
4051 operand_reloadnum[i] = output_reloadnum;
4053 else
4055 gcc_assert (insn_code_number < 0);
4056 error_for_asm (insn, "inconsistent operand constraints "
4057 "in an %<asm%>");
4058 /* Avoid further trouble with this insn. */
4059 PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
4060 n_reloads = 0;
4061 return 0;
4064 else if (goal_alternative_matched[i] < 0
4065 && goal_alternative_matches[i] < 0
4066 && address_operand_reloaded[i] != 1
4067 && optimize)
4069 /* For each non-matching operand that's a MEM or a pseudo-register
4070 that didn't get a hard register, make an optional reload.
4071 This may get done even if the insn needs no reloads otherwise. */
4073 rtx operand = recog_data.operand[i];
4075 while (GET_CODE (operand) == SUBREG)
4076 operand = SUBREG_REG (operand);
4077 if ((MEM_P (operand)
4078 || (REG_P (operand)
4079 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4080 /* If this is only for an output, the optional reload would not
4081 actually cause us to use a register now, just note that
4082 something is stored here. */
4083 && (goal_alternative[i] != NO_REGS
4084 || modified[i] == RELOAD_WRITE)
4085 && ! no_input_reloads
4086 /* An optional output reload might allow to delete INSN later.
4087 We mustn't make in-out reloads on insns that are not permitted
4088 output reloads.
4089 If this is an asm, we can't delete it; we must not even call
4090 push_reload for an optional output reload in this case,
4091 because we can't be sure that the constraint allows a register,
4092 and push_reload verifies the constraints for asms. */
4093 && (modified[i] == RELOAD_READ
4094 || (! no_output_reloads && ! this_insn_is_asm)))
4095 operand_reloadnum[i]
4096 = push_reload ((modified[i] != RELOAD_WRITE
4097 ? recog_data.operand[i] : 0),
4098 (modified[i] != RELOAD_READ
4099 ? recog_data.operand[i] : 0),
4100 (modified[i] != RELOAD_WRITE
4101 ? recog_data.operand_loc[i] : 0),
4102 (modified[i] != RELOAD_READ
4103 ? recog_data.operand_loc[i] : 0),
4104 (enum reg_class) goal_alternative[i],
4105 (modified[i] == RELOAD_WRITE
4106 ? VOIDmode : operand_mode[i]),
4107 (modified[i] == RELOAD_READ
4108 ? VOIDmode : operand_mode[i]),
4109 (insn_code_number < 0 ? 0
4110 : insn_data[insn_code_number].operand[i].strict_low),
4111 1, i, operand_type[i]);
4112 /* If a memory reference remains (either as a MEM or a pseudo that
4113 did not get a hard register), yet we can't make an optional
4114 reload, check if this is actually a pseudo register reference;
4115 we then need to emit a USE and/or a CLOBBER so that reload
4116 inheritance will do the right thing. */
4117 else if (replace
4118 && (MEM_P (operand)
4119 || (REG_P (operand)
4120 && REGNO (operand) >= FIRST_PSEUDO_REGISTER
4121 && reg_renumber [REGNO (operand)] < 0)))
4123 operand = *recog_data.operand_loc[i];
4125 while (GET_CODE (operand) == SUBREG)
4126 operand = SUBREG_REG (operand);
4127 if (REG_P (operand))
4129 if (modified[i] != RELOAD_WRITE)
4130 /* We mark the USE with QImode so that we recognize
4131 it as one that can be safely deleted at the end
4132 of reload. */
4133 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, operand),
4134 insn), QImode);
4135 if (modified[i] != RELOAD_READ)
4136 emit_insn_after (gen_clobber (operand), insn);
4140 else if (goal_alternative_matches[i] >= 0
4141 && goal_alternative_win[goal_alternative_matches[i]]
4142 && modified[i] == RELOAD_READ
4143 && modified[goal_alternative_matches[i]] == RELOAD_WRITE
4144 && ! no_input_reloads && ! no_output_reloads
4145 && optimize)
4147 /* Similarly, make an optional reload for a pair of matching
4148 objects that are in MEM or a pseudo that didn't get a hard reg. */
4150 rtx operand = recog_data.operand[i];
4152 while (GET_CODE (operand) == SUBREG)
4153 operand = SUBREG_REG (operand);
4154 if ((MEM_P (operand)
4155 || (REG_P (operand)
4156 && REGNO (operand) >= FIRST_PSEUDO_REGISTER))
4157 && (goal_alternative[goal_alternative_matches[i]] != NO_REGS))
4158 operand_reloadnum[i] = operand_reloadnum[goal_alternative_matches[i]]
4159 = push_reload (recog_data.operand[goal_alternative_matches[i]],
4160 recog_data.operand[i],
4161 recog_data.operand_loc[goal_alternative_matches[i]],
4162 recog_data.operand_loc[i],
4163 (enum reg_class) goal_alternative[goal_alternative_matches[i]],
4164 operand_mode[goal_alternative_matches[i]],
4165 operand_mode[i],
4166 0, 1, goal_alternative_matches[i], RELOAD_OTHER);
4169 /* Perform whatever substitutions on the operands we are supposed
4170 to make due to commutativity or replacement of registers
4171 with equivalent constants or memory slots. */
4173 for (i = 0; i < noperands; i++)
4175 /* We only do this on the last pass through reload, because it is
4176 possible for some data (like reg_equiv_address) to be changed during
4177 later passes. Moreover, we lose the opportunity to get a useful
4178 reload_{in,out}_reg when we do these replacements. */
4180 if (replace)
4182 rtx substitution = substed_operand[i];
4184 *recog_data.operand_loc[i] = substitution;
4186 /* If we're replacing an operand with a LABEL_REF, we need to
4187 make sure that there's a REG_LABEL_OPERAND note attached to
4188 this instruction. */
4189 if (GET_CODE (substitution) == LABEL_REF
4190 && !find_reg_note (insn, REG_LABEL_OPERAND,
4191 label_ref_label (substitution))
4192 /* For a JUMP_P, if it was a branch target it must have
4193 already been recorded as such. */
4194 && (!JUMP_P (insn)
4195 || !label_is_jump_target_p (label_ref_label (substitution),
4196 insn)))
4198 add_reg_note (insn, REG_LABEL_OPERAND,
4199 label_ref_label (substitution));
4200 if (LABEL_P (label_ref_label (substitution)))
4201 ++LABEL_NUSES (label_ref_label (substitution));
4205 else
4206 retval |= (substed_operand[i] != *recog_data.operand_loc[i]);
4209 /* If this insn pattern contains any MATCH_DUP's, make sure that
4210 they will be substituted if the operands they match are substituted.
4211 Also do now any substitutions we already did on the operands.
4213 Don't do this if we aren't making replacements because we might be
4214 propagating things allocated by frame pointer elimination into places
4215 it doesn't expect. */
4217 if (insn_code_number >= 0 && replace)
4218 for (i = insn_data[insn_code_number].n_dups - 1; i >= 0; i--)
4220 int opno = recog_data.dup_num[i];
4221 *recog_data.dup_loc[i] = *recog_data.operand_loc[opno];
4222 dup_replacements (recog_data.dup_loc[i], recog_data.operand_loc[opno]);
4225 #if 0
4226 /* This loses because reloading of prior insns can invalidate the equivalence
4227 (or at least find_equiv_reg isn't smart enough to find it any more),
4228 causing this insn to need more reload regs than it needed before.
4229 It may be too late to make the reload regs available.
4230 Now this optimization is done safely in choose_reload_regs. */
4232 /* For each reload of a reg into some other class of reg,
4233 search for an existing equivalent reg (same value now) in the right class.
4234 We can use it as long as we don't need to change its contents. */
4235 for (i = 0; i < n_reloads; i++)
4236 if (rld[i].reg_rtx == 0
4237 && rld[i].in != 0
4238 && REG_P (rld[i].in)
4239 && rld[i].out == 0)
4241 rld[i].reg_rtx
4242 = find_equiv_reg (rld[i].in, insn, rld[i].rclass, -1,
4243 static_reload_reg_p, 0, rld[i].inmode);
4244 /* Prevent generation of insn to load the value
4245 because the one we found already has the value. */
4246 if (rld[i].reg_rtx)
4247 rld[i].in = rld[i].reg_rtx;
4249 #endif
4251 /* If we detected error and replaced asm instruction by USE, forget about the
4252 reloads. */
4253 if (GET_CODE (PATTERN (insn)) == USE
4254 && CONST_INT_P (XEXP (PATTERN (insn), 0)))
4255 n_reloads = 0;
4257 /* Perhaps an output reload can be combined with another
4258 to reduce needs by one. */
4259 if (!goal_earlyclobber)
4260 combine_reloads ();
4262 /* If we have a pair of reloads for parts of an address, they are reloading
4263 the same object, the operands themselves were not reloaded, and they
4264 are for two operands that are supposed to match, merge the reloads and
4265 change the type of the surviving reload to RELOAD_FOR_OPERAND_ADDRESS. */
4267 for (i = 0; i < n_reloads; i++)
4269 int k;
4271 for (j = i + 1; j < n_reloads; j++)
4272 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4273 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4274 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4275 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4276 && (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
4277 || rld[j].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4278 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4279 || rld[j].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4280 && rtx_equal_p (rld[i].in, rld[j].in)
4281 && (operand_reloadnum[rld[i].opnum] < 0
4282 || rld[operand_reloadnum[rld[i].opnum]].optional)
4283 && (operand_reloadnum[rld[j].opnum] < 0
4284 || rld[operand_reloadnum[rld[j].opnum]].optional)
4285 && (goal_alternative_matches[rld[i].opnum] == rld[j].opnum
4286 || (goal_alternative_matches[rld[j].opnum]
4287 == rld[i].opnum)))
4289 for (k = 0; k < n_replacements; k++)
4290 if (replacements[k].what == j)
4291 replacements[k].what = i;
4293 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4294 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4295 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4296 else
4297 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4298 rld[j].in = 0;
4302 /* Scan all the reloads and update their type.
4303 If a reload is for the address of an operand and we didn't reload
4304 that operand, change the type. Similarly, change the operand number
4305 of a reload when two operands match. If a reload is optional, treat it
4306 as though the operand isn't reloaded.
4308 ??? This latter case is somewhat odd because if we do the optional
4309 reload, it means the object is hanging around. Thus we need only
4310 do the address reload if the optional reload was NOT done.
4312 Change secondary reloads to be the address type of their operand, not
4313 the normal type.
4315 If an operand's reload is now RELOAD_OTHER, change any
4316 RELOAD_FOR_INPUT_ADDRESS reloads of that operand to
4317 RELOAD_FOR_OTHER_ADDRESS. */
4319 for (i = 0; i < n_reloads; i++)
4321 if (rld[i].secondary_p
4322 && rld[i].when_needed == operand_type[rld[i].opnum])
4323 rld[i].when_needed = address_type[rld[i].opnum];
4325 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4326 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4327 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4328 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4329 && (operand_reloadnum[rld[i].opnum] < 0
4330 || rld[operand_reloadnum[rld[i].opnum]].optional))
4332 /* If we have a secondary reload to go along with this reload,
4333 change its type to RELOAD_FOR_OPADDR_ADDR. */
4335 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4336 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4337 && rld[i].secondary_in_reload != -1)
4339 int secondary_in_reload = rld[i].secondary_in_reload;
4341 rld[secondary_in_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4343 /* If there's a tertiary reload we have to change it also. */
4344 if (secondary_in_reload > 0
4345 && rld[secondary_in_reload].secondary_in_reload != -1)
4346 rld[rld[secondary_in_reload].secondary_in_reload].when_needed
4347 = RELOAD_FOR_OPADDR_ADDR;
4350 if ((rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS
4351 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4352 && rld[i].secondary_out_reload != -1)
4354 int secondary_out_reload = rld[i].secondary_out_reload;
4356 rld[secondary_out_reload].when_needed = RELOAD_FOR_OPADDR_ADDR;
4358 /* If there's a tertiary reload we have to change it also. */
4359 if (secondary_out_reload
4360 && rld[secondary_out_reload].secondary_out_reload != -1)
4361 rld[rld[secondary_out_reload].secondary_out_reload].when_needed
4362 = RELOAD_FOR_OPADDR_ADDR;
4365 if (rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS
4366 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS)
4367 rld[i].when_needed = RELOAD_FOR_OPADDR_ADDR;
4368 else
4369 rld[i].when_needed = RELOAD_FOR_OPERAND_ADDRESS;
4372 if ((rld[i].when_needed == RELOAD_FOR_INPUT_ADDRESS
4373 || rld[i].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
4374 && operand_reloadnum[rld[i].opnum] >= 0
4375 && (rld[operand_reloadnum[rld[i].opnum]].when_needed
4376 == RELOAD_OTHER))
4377 rld[i].when_needed = RELOAD_FOR_OTHER_ADDRESS;
4379 if (goal_alternative_matches[rld[i].opnum] >= 0)
4380 rld[i].opnum = goal_alternative_matches[rld[i].opnum];
4383 /* Scan all the reloads, and check for RELOAD_FOR_OPERAND_ADDRESS reloads.
4384 If we have more than one, then convert all RELOAD_FOR_OPADDR_ADDR
4385 reloads to RELOAD_FOR_OPERAND_ADDRESS reloads.
4387 choose_reload_regs assumes that RELOAD_FOR_OPADDR_ADDR reloads never
4388 conflict with RELOAD_FOR_OPERAND_ADDRESS reloads. This is true for a
4389 single pair of RELOAD_FOR_OPADDR_ADDR/RELOAD_FOR_OPERAND_ADDRESS reloads.
4390 However, if there is more than one RELOAD_FOR_OPERAND_ADDRESS reload,
4391 then a RELOAD_FOR_OPADDR_ADDR reload conflicts with all
4392 RELOAD_FOR_OPERAND_ADDRESS reloads other than the one that uses it.
4393 This is complicated by the fact that a single operand can have more
4394 than one RELOAD_FOR_OPERAND_ADDRESS reload. It is very difficult to fix
4395 choose_reload_regs without affecting code quality, and cases that
4396 actually fail are extremely rare, so it turns out to be better to fix
4397 the problem here by not generating cases that choose_reload_regs will
4398 fail for. */
4399 /* There is a similar problem with RELOAD_FOR_INPUT_ADDRESS /
4400 RELOAD_FOR_OUTPUT_ADDRESS when there is more than one of a kind for
4401 a single operand.
4402 We can reduce the register pressure by exploiting that a
4403 RELOAD_FOR_X_ADDR_ADDR that precedes all RELOAD_FOR_X_ADDRESS reloads
4404 does not conflict with any of them, if it is only used for the first of
4405 the RELOAD_FOR_X_ADDRESS reloads. */
4407 int first_op_addr_num = -2;
4408 int first_inpaddr_num[MAX_RECOG_OPERANDS];
4409 int first_outpaddr_num[MAX_RECOG_OPERANDS];
4410 int need_change = 0;
4411 /* We use last_op_addr_reload and the contents of the above arrays
4412 first as flags - -2 means no instance encountered, -1 means exactly
4413 one instance encountered.
4414 If more than one instance has been encountered, we store the reload
4415 number of the first reload of the kind in question; reload numbers
4416 are known to be non-negative. */
4417 for (i = 0; i < noperands; i++)
4418 first_inpaddr_num[i] = first_outpaddr_num[i] = -2;
4419 for (i = n_reloads - 1; i >= 0; i--)
4421 switch (rld[i].when_needed)
4423 case RELOAD_FOR_OPERAND_ADDRESS:
4424 if (++first_op_addr_num >= 0)
4426 first_op_addr_num = i;
4427 need_change = 1;
4429 break;
4430 case RELOAD_FOR_INPUT_ADDRESS:
4431 if (++first_inpaddr_num[rld[i].opnum] >= 0)
4433 first_inpaddr_num[rld[i].opnum] = i;
4434 need_change = 1;
4436 break;
4437 case RELOAD_FOR_OUTPUT_ADDRESS:
4438 if (++first_outpaddr_num[rld[i].opnum] >= 0)
4440 first_outpaddr_num[rld[i].opnum] = i;
4441 need_change = 1;
4443 break;
4444 default:
4445 break;
4449 if (need_change)
4451 for (i = 0; i < n_reloads; i++)
4453 int first_num;
4454 enum reload_type type;
4456 switch (rld[i].when_needed)
4458 case RELOAD_FOR_OPADDR_ADDR:
4459 first_num = first_op_addr_num;
4460 type = RELOAD_FOR_OPERAND_ADDRESS;
4461 break;
4462 case RELOAD_FOR_INPADDR_ADDRESS:
4463 first_num = first_inpaddr_num[rld[i].opnum];
4464 type = RELOAD_FOR_INPUT_ADDRESS;
4465 break;
4466 case RELOAD_FOR_OUTADDR_ADDRESS:
4467 first_num = first_outpaddr_num[rld[i].opnum];
4468 type = RELOAD_FOR_OUTPUT_ADDRESS;
4469 break;
4470 default:
4471 continue;
4473 if (first_num < 0)
4474 continue;
4475 else if (i > first_num)
4476 rld[i].when_needed = type;
4477 else
4479 /* Check if the only TYPE reload that uses reload I is
4480 reload FIRST_NUM. */
4481 for (j = n_reloads - 1; j > first_num; j--)
4483 if (rld[j].when_needed == type
4484 && (rld[i].secondary_p
4485 ? rld[j].secondary_in_reload == i
4486 : reg_mentioned_p (rld[i].in, rld[j].in)))
4488 rld[i].when_needed = type;
4489 break;
4497 /* See if we have any reloads that are now allowed to be merged
4498 because we've changed when the reload is needed to
4499 RELOAD_FOR_OPERAND_ADDRESS or RELOAD_FOR_OTHER_ADDRESS. Only
4500 check for the most common cases. */
4502 for (i = 0; i < n_reloads; i++)
4503 if (rld[i].in != 0 && rld[i].out == 0
4504 && (rld[i].when_needed == RELOAD_FOR_OPERAND_ADDRESS
4505 || rld[i].when_needed == RELOAD_FOR_OPADDR_ADDR
4506 || rld[i].when_needed == RELOAD_FOR_OTHER_ADDRESS))
4507 for (j = 0; j < n_reloads; j++)
4508 if (i != j && rld[j].in != 0 && rld[j].out == 0
4509 && rld[j].when_needed == rld[i].when_needed
4510 && MATCHES (rld[i].in, rld[j].in)
4511 && rld[i].rclass == rld[j].rclass
4512 && !rld[i].nocombine && !rld[j].nocombine
4513 && rld[i].reg_rtx == rld[j].reg_rtx)
4515 rld[i].opnum = MIN (rld[i].opnum, rld[j].opnum);
4516 transfer_replacements (i, j);
4517 rld[j].in = 0;
4520 /* If we made any reloads for addresses, see if they violate a
4521 "no input reloads" requirement for this insn. But loads that we
4522 do after the insn (such as for output addresses) are fine. */
4523 if (HAVE_cc0 && no_input_reloads)
4524 for (i = 0; i < n_reloads; i++)
4525 gcc_assert (rld[i].in == 0
4526 || rld[i].when_needed == RELOAD_FOR_OUTADDR_ADDRESS
4527 || rld[i].when_needed == RELOAD_FOR_OUTPUT_ADDRESS);
4529 /* Compute reload_mode and reload_nregs. */
4530 for (i = 0; i < n_reloads; i++)
4532 rld[i].mode = rld[i].inmode;
4533 if (rld[i].mode == VOIDmode
4534 || partial_subreg_p (rld[i].mode, rld[i].outmode))
4535 rld[i].mode = rld[i].outmode;
4537 rld[i].nregs = ira_reg_class_max_nregs [rld[i].rclass][rld[i].mode];
4540 /* Special case a simple move with an input reload and a
4541 destination of a hard reg, if the hard reg is ok, use it. */
4542 for (i = 0; i < n_reloads; i++)
4543 if (rld[i].when_needed == RELOAD_FOR_INPUT
4544 && GET_CODE (PATTERN (insn)) == SET
4545 && REG_P (SET_DEST (PATTERN (insn)))
4546 && (SET_SRC (PATTERN (insn)) == rld[i].in
4547 || SET_SRC (PATTERN (insn)) == rld[i].in_reg)
4548 && !elimination_target_reg_p (SET_DEST (PATTERN (insn))))
4550 rtx dest = SET_DEST (PATTERN (insn));
4551 unsigned int regno = REGNO (dest);
4553 if (regno < FIRST_PSEUDO_REGISTER
4554 && TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno)
4555 && targetm.hard_regno_mode_ok (regno, rld[i].mode))
4557 int nr = hard_regno_nregs (regno, rld[i].mode);
4558 int ok = 1, nri;
4560 for (nri = 1; nri < nr; nri ++)
4561 if (! TEST_HARD_REG_BIT (reg_class_contents[rld[i].rclass], regno + nri))
4563 ok = 0;
4564 break;
4567 if (ok)
4568 rld[i].reg_rtx = dest;
4572 return retval;
4575 /* Return true if alternative number ALTNUM in constraint-string
4576 CONSTRAINT is guaranteed to accept a reloaded constant-pool reference.
4577 MEM gives the reference if its address hasn't been fully reloaded,
4578 otherwise it is NULL. */
4580 static bool
4581 alternative_allows_const_pool_ref (rtx mem ATTRIBUTE_UNUSED,
4582 const char *constraint, int altnum)
4584 int c;
4586 /* Skip alternatives before the one requested. */
4587 while (altnum > 0)
4589 while (*constraint++ != ',')
4591 altnum--;
4593 /* Scan the requested alternative for TARGET_MEM_CONSTRAINT or 'o'.
4594 If one of them is present, this alternative accepts the result of
4595 passing a constant-pool reference through find_reloads_toplev.
4597 The same is true of extra memory constraints if the address
4598 was reloaded into a register. However, the target may elect
4599 to disallow the original constant address, forcing it to be
4600 reloaded into a register instead. */
4601 for (; (c = *constraint) && c != ',' && c != '#';
4602 constraint += CONSTRAINT_LEN (c, constraint))
4604 enum constraint_num cn = lookup_constraint (constraint);
4605 if (insn_extra_memory_constraint (cn)
4606 && (mem == NULL || constraint_satisfied_p (mem, cn)))
4607 return true;
4609 return false;
4612 /* Scan X for memory references and scan the addresses for reloading.
4613 Also checks for references to "constant" regs that we want to eliminate
4614 and replaces them with the values they stand for.
4615 We may alter X destructively if it contains a reference to such.
4616 If X is just a constant reg, we return the equivalent value
4617 instead of X.
4619 IND_LEVELS says how many levels of indirect addressing this machine
4620 supports.
4622 OPNUM and TYPE identify the purpose of the reload.
4624 IS_SET_DEST is true if X is the destination of a SET, which is not
4625 appropriate to be replaced by a constant.
4627 INSN, if nonzero, is the insn in which we do the reload. It is used
4628 to determine if we may generate output reloads, and where to put USEs
4629 for pseudos that we have to replace with stack slots.
4631 ADDRESS_RELOADED. If nonzero, is a pointer to where we put the
4632 result of find_reloads_address. */
4634 static rtx
4635 find_reloads_toplev (rtx x, int opnum, enum reload_type type,
4636 int ind_levels, int is_set_dest, rtx_insn *insn,
4637 int *address_reloaded)
4639 RTX_CODE code = GET_CODE (x);
4641 const char *fmt = GET_RTX_FORMAT (code);
4642 int i;
4643 int copied;
4645 if (code == REG)
4647 /* This code is duplicated for speed in find_reloads. */
4648 int regno = REGNO (x);
4649 if (reg_equiv_constant (regno) != 0 && !is_set_dest)
4650 x = reg_equiv_constant (regno);
4651 #if 0
4652 /* This creates (subreg (mem...)) which would cause an unnecessary
4653 reload of the mem. */
4654 else if (reg_equiv_mem (regno) != 0)
4655 x = reg_equiv_mem (regno);
4656 #endif
4657 else if (reg_equiv_memory_loc (regno)
4658 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
4660 rtx mem = make_memloc (x, regno);
4661 if (reg_equiv_address (regno)
4662 || ! rtx_equal_p (mem, reg_equiv_mem (regno)))
4664 /* If this is not a toplevel operand, find_reloads doesn't see
4665 this substitution. We have to emit a USE of the pseudo so
4666 that delete_output_reload can see it. */
4667 if (replace_reloads && recog_data.operand[opnum] != x)
4668 /* We mark the USE with QImode so that we recognize it
4669 as one that can be safely deleted at the end of
4670 reload. */
4671 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, x), insn),
4672 QImode);
4673 x = mem;
4674 i = find_reloads_address (GET_MODE (x), &x, XEXP (x, 0), &XEXP (x, 0),
4675 opnum, type, ind_levels, insn);
4676 if (!rtx_equal_p (x, mem))
4677 push_reg_equiv_alt_mem (regno, x);
4678 if (address_reloaded)
4679 *address_reloaded = i;
4682 return x;
4684 if (code == MEM)
4686 rtx tem = x;
4688 i = find_reloads_address (GET_MODE (x), &tem, XEXP (x, 0), &XEXP (x, 0),
4689 opnum, type, ind_levels, insn);
4690 if (address_reloaded)
4691 *address_reloaded = i;
4693 return tem;
4696 if (code == SUBREG && REG_P (SUBREG_REG (x)))
4698 /* Check for SUBREG containing a REG that's equivalent to a
4699 constant. If the constant has a known value, truncate it
4700 right now. Similarly if we are extracting a single-word of a
4701 multi-word constant. If the constant is symbolic, allow it
4702 to be substituted normally. push_reload will strip the
4703 subreg later. The constant must not be VOIDmode, because we
4704 will lose the mode of the register (this should never happen
4705 because one of the cases above should handle it). */
4707 int regno = REGNO (SUBREG_REG (x));
4708 rtx tem;
4710 if (regno >= FIRST_PSEUDO_REGISTER
4711 && reg_renumber[regno] < 0
4712 && reg_equiv_constant (regno) != 0)
4714 tem =
4715 simplify_gen_subreg (GET_MODE (x), reg_equiv_constant (regno),
4716 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
4717 gcc_assert (tem);
4718 if (CONSTANT_P (tem)
4719 && !targetm.legitimate_constant_p (GET_MODE (x), tem))
4721 tem = force_const_mem (GET_MODE (x), tem);
4722 i = find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4723 &XEXP (tem, 0), opnum, type,
4724 ind_levels, insn);
4725 if (address_reloaded)
4726 *address_reloaded = i;
4728 return tem;
4731 /* If the subreg contains a reg that will be converted to a mem,
4732 attempt to convert the whole subreg to a (narrower or wider)
4733 memory reference instead. If this succeeds, we're done --
4734 otherwise fall through to check whether the inner reg still
4735 needs address reloads anyway. */
4737 if (regno >= FIRST_PSEUDO_REGISTER
4738 && reg_equiv_memory_loc (regno) != 0)
4740 tem = find_reloads_subreg_address (x, opnum, type, ind_levels,
4741 insn, address_reloaded);
4742 if (tem)
4743 return tem;
4747 for (copied = 0, i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
4749 if (fmt[i] == 'e')
4751 rtx new_part = find_reloads_toplev (XEXP (x, i), opnum, type,
4752 ind_levels, is_set_dest, insn,
4753 address_reloaded);
4754 /* If we have replaced a reg with it's equivalent memory loc -
4755 that can still be handled here e.g. if it's in a paradoxical
4756 subreg - we must make the change in a copy, rather than using
4757 a destructive change. This way, find_reloads can still elect
4758 not to do the change. */
4759 if (new_part != XEXP (x, i) && ! CONSTANT_P (new_part) && ! copied)
4761 x = shallow_copy_rtx (x);
4762 copied = 1;
4764 XEXP (x, i) = new_part;
4767 return x;
4770 /* Return a mem ref for the memory equivalent of reg REGNO.
4771 This mem ref is not shared with anything. */
4773 static rtx
4774 make_memloc (rtx ad, int regno)
4776 /* We must rerun eliminate_regs, in case the elimination
4777 offsets have changed. */
4778 rtx tem
4779 = XEXP (eliminate_regs (reg_equiv_memory_loc (regno), VOIDmode, NULL_RTX),
4782 /* If TEM might contain a pseudo, we must copy it to avoid
4783 modifying it when we do the substitution for the reload. */
4784 if (rtx_varies_p (tem, 0))
4785 tem = copy_rtx (tem);
4787 tem = replace_equiv_address_nv (reg_equiv_memory_loc (regno), tem);
4788 tem = adjust_address_nv (tem, GET_MODE (ad), 0);
4790 /* Copy the result if it's still the same as the equivalence, to avoid
4791 modifying it when we do the substitution for the reload. */
4792 if (tem == reg_equiv_memory_loc (regno))
4793 tem = copy_rtx (tem);
4794 return tem;
4797 /* Returns true if AD could be turned into a valid memory reference
4798 to mode MODE in address space AS by reloading the part pointed to
4799 by PART into a register. */
4801 static int
4802 maybe_memory_address_addr_space_p (machine_mode mode, rtx ad,
4803 addr_space_t as, rtx *part)
4805 int retv;
4806 rtx tem = *part;
4807 rtx reg = gen_rtx_REG (GET_MODE (tem), max_reg_num ());
4809 *part = reg;
4810 retv = memory_address_addr_space_p (mode, ad, as);
4811 *part = tem;
4813 return retv;
4816 /* Record all reloads needed for handling memory address AD
4817 which appears in *LOC in a memory reference to mode MODE
4818 which itself is found in location *MEMREFLOC.
4819 Note that we take shortcuts assuming that no multi-reg machine mode
4820 occurs as part of an address.
4822 OPNUM and TYPE specify the purpose of this reload.
4824 IND_LEVELS says how many levels of indirect addressing this machine
4825 supports.
4827 INSN, if nonzero, is the insn in which we do the reload. It is used
4828 to determine if we may generate output reloads, and where to put USEs
4829 for pseudos that we have to replace with stack slots.
4831 Value is one if this address is reloaded or replaced as a whole; it is
4832 zero if the top level of this address was not reloaded or replaced, and
4833 it is -1 if it may or may not have been reloaded or replaced.
4835 Note that there is no verification that the address will be valid after
4836 this routine does its work. Instead, we rely on the fact that the address
4837 was valid when reload started. So we need only undo things that reload
4838 could have broken. These are wrong register types, pseudos not allocated
4839 to a hard register, and frame pointer elimination. */
4841 static int
4842 find_reloads_address (machine_mode mode, rtx *memrefloc, rtx ad,
4843 rtx *loc, int opnum, enum reload_type type,
4844 int ind_levels, rtx_insn *insn)
4846 addr_space_t as = memrefloc? MEM_ADDR_SPACE (*memrefloc)
4847 : ADDR_SPACE_GENERIC;
4848 int regno;
4849 int removed_and = 0;
4850 int op_index;
4851 rtx tem;
4853 /* If the address is a register, see if it is a legitimate address and
4854 reload if not. We first handle the cases where we need not reload
4855 or where we must reload in a non-standard way. */
4857 if (REG_P (ad))
4859 regno = REGNO (ad);
4861 if (reg_equiv_constant (regno) != 0)
4863 find_reloads_address_part (reg_equiv_constant (regno), loc,
4864 base_reg_class (mode, as, MEM, SCRATCH),
4865 GET_MODE (ad), opnum, type, ind_levels);
4866 return 1;
4869 tem = reg_equiv_memory_loc (regno);
4870 if (tem != 0)
4872 if (reg_equiv_address (regno) != 0 || num_not_at_initial_offset)
4874 tem = make_memloc (ad, regno);
4875 if (! strict_memory_address_addr_space_p (GET_MODE (tem),
4876 XEXP (tem, 0),
4877 MEM_ADDR_SPACE (tem)))
4879 rtx orig = tem;
4881 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
4882 &XEXP (tem, 0), opnum,
4883 ADDR_TYPE (type), ind_levels, insn);
4884 if (!rtx_equal_p (tem, orig))
4885 push_reg_equiv_alt_mem (regno, tem);
4887 /* We can avoid a reload if the register's equivalent memory
4888 expression is valid as an indirect memory address.
4889 But not all addresses are valid in a mem used as an indirect
4890 address: only reg or reg+constant. */
4892 if (ind_levels > 0
4893 && strict_memory_address_addr_space_p (mode, tem, as)
4894 && (REG_P (XEXP (tem, 0))
4895 || (GET_CODE (XEXP (tem, 0)) == PLUS
4896 && REG_P (XEXP (XEXP (tem, 0), 0))
4897 && CONSTANT_P (XEXP (XEXP (tem, 0), 1)))))
4899 /* TEM is not the same as what we'll be replacing the
4900 pseudo with after reload, put a USE in front of INSN
4901 in the final reload pass. */
4902 if (replace_reloads
4903 && num_not_at_initial_offset
4904 && ! rtx_equal_p (tem, reg_equiv_mem (regno)))
4906 *loc = tem;
4907 /* We mark the USE with QImode so that we
4908 recognize it as one that can be safely
4909 deleted at the end of reload. */
4910 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad),
4911 insn), QImode);
4913 /* This doesn't really count as replacing the address
4914 as a whole, since it is still a memory access. */
4916 return 0;
4918 ad = tem;
4922 /* The only remaining case where we can avoid a reload is if this is a
4923 hard register that is valid as a base register and which is not the
4924 subject of a CLOBBER in this insn. */
4926 else if (regno < FIRST_PSEUDO_REGISTER
4927 && regno_ok_for_base_p (regno, mode, as, MEM, SCRATCH)
4928 && ! regno_clobbered_p (regno, this_insn, mode, 0))
4929 return 0;
4931 /* If we do not have one of the cases above, we must do the reload. */
4932 push_reload (ad, NULL_RTX, loc, (rtx*) 0,
4933 base_reg_class (mode, as, MEM, SCRATCH),
4934 GET_MODE (ad), VOIDmode, 0, 0, opnum, type);
4935 return 1;
4938 if (strict_memory_address_addr_space_p (mode, ad, as))
4940 /* The address appears valid, so reloads are not needed.
4941 But the address may contain an eliminable register.
4942 This can happen because a machine with indirect addressing
4943 may consider a pseudo register by itself a valid address even when
4944 it has failed to get a hard reg.
4945 So do a tree-walk to find and eliminate all such regs. */
4947 /* But first quickly dispose of a common case. */
4948 if (GET_CODE (ad) == PLUS
4949 && CONST_INT_P (XEXP (ad, 1))
4950 && REG_P (XEXP (ad, 0))
4951 && reg_equiv_constant (REGNO (XEXP (ad, 0))) == 0)
4952 return 0;
4954 subst_reg_equivs_changed = 0;
4955 *loc = subst_reg_equivs (ad, insn);
4957 if (! subst_reg_equivs_changed)
4958 return 0;
4960 /* Check result for validity after substitution. */
4961 if (strict_memory_address_addr_space_p (mode, ad, as))
4962 return 0;
4965 #ifdef LEGITIMIZE_RELOAD_ADDRESS
4968 if (memrefloc && ADDR_SPACE_GENERIC_P (as))
4970 LEGITIMIZE_RELOAD_ADDRESS (ad, GET_MODE (*memrefloc), opnum, type,
4971 ind_levels, win);
4973 break;
4974 win:
4975 *memrefloc = copy_rtx (*memrefloc);
4976 XEXP (*memrefloc, 0) = ad;
4977 move_replacements (&ad, &XEXP (*memrefloc, 0));
4978 return -1;
4980 while (0);
4981 #endif
4983 /* The address is not valid. We have to figure out why. First see if
4984 we have an outer AND and remove it if so. Then analyze what's inside. */
4986 if (GET_CODE (ad) == AND)
4988 removed_and = 1;
4989 loc = &XEXP (ad, 0);
4990 ad = *loc;
4993 /* One possibility for why the address is invalid is that it is itself
4994 a MEM. This can happen when the frame pointer is being eliminated, a
4995 pseudo is not allocated to a hard register, and the offset between the
4996 frame and stack pointers is not its initial value. In that case the
4997 pseudo will have been replaced by a MEM referring to the
4998 stack pointer. */
4999 if (MEM_P (ad))
5001 /* First ensure that the address in this MEM is valid. Then, unless
5002 indirect addresses are valid, reload the MEM into a register. */
5003 tem = ad;
5004 find_reloads_address (GET_MODE (ad), &tem, XEXP (ad, 0), &XEXP (ad, 0),
5005 opnum, ADDR_TYPE (type),
5006 ind_levels == 0 ? 0 : ind_levels - 1, insn);
5008 /* If tem was changed, then we must create a new memory reference to
5009 hold it and store it back into memrefloc. */
5010 if (tem != ad && memrefloc)
5012 *memrefloc = copy_rtx (*memrefloc);
5013 copy_replacements (tem, XEXP (*memrefloc, 0));
5014 loc = &XEXP (*memrefloc, 0);
5015 if (removed_and)
5016 loc = &XEXP (*loc, 0);
5019 /* Check similar cases as for indirect addresses as above except
5020 that we can allow pseudos and a MEM since they should have been
5021 taken care of above. */
5023 if (ind_levels == 0
5024 || (GET_CODE (XEXP (tem, 0)) == SYMBOL_REF && ! indirect_symref_ok)
5025 || MEM_P (XEXP (tem, 0))
5026 || ! (REG_P (XEXP (tem, 0))
5027 || (GET_CODE (XEXP (tem, 0)) == PLUS
5028 && REG_P (XEXP (XEXP (tem, 0), 0))
5029 && CONST_INT_P (XEXP (XEXP (tem, 0), 1)))))
5031 /* Must use TEM here, not AD, since it is the one that will
5032 have any subexpressions reloaded, if needed. */
5033 push_reload (tem, NULL_RTX, loc, (rtx*) 0,
5034 base_reg_class (mode, as, MEM, SCRATCH), GET_MODE (tem),
5035 VOIDmode, 0,
5036 0, opnum, type);
5037 return ! removed_and;
5039 else
5040 return 0;
5043 /* If we have address of a stack slot but it's not valid because the
5044 displacement is too large, compute the sum in a register.
5045 Handle all base registers here, not just fp/ap/sp, because on some
5046 targets (namely SH) we can also get too large displacements from
5047 big-endian corrections. */
5048 else if (GET_CODE (ad) == PLUS
5049 && REG_P (XEXP (ad, 0))
5050 && REGNO (XEXP (ad, 0)) < FIRST_PSEUDO_REGISTER
5051 && CONST_INT_P (XEXP (ad, 1))
5052 && (regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, as, PLUS,
5053 CONST_INT)
5054 /* Similarly, if we were to reload the base register and the
5055 mem+offset address is still invalid, then we want to reload
5056 the whole address, not just the base register. */
5057 || ! maybe_memory_address_addr_space_p
5058 (mode, ad, as, &(XEXP (ad, 0)))))
5061 /* Unshare the MEM rtx so we can safely alter it. */
5062 if (memrefloc)
5064 *memrefloc = copy_rtx (*memrefloc);
5065 loc = &XEXP (*memrefloc, 0);
5066 if (removed_and)
5067 loc = &XEXP (*loc, 0);
5070 if (double_reg_address_ok[mode]
5071 && regno_ok_for_base_p (REGNO (XEXP (ad, 0)), mode, as,
5072 PLUS, CONST_INT))
5074 /* Unshare the sum as well. */
5075 *loc = ad = copy_rtx (ad);
5077 /* Reload the displacement into an index reg.
5078 We assume the frame pointer or arg pointer is a base reg. */
5079 find_reloads_address_part (XEXP (ad, 1), &XEXP (ad, 1),
5080 INDEX_REG_CLASS, GET_MODE (ad), opnum,
5081 type, ind_levels);
5082 return 0;
5084 else
5086 /* If the sum of two regs is not necessarily valid,
5087 reload the sum into a base reg.
5088 That will at least work. */
5089 find_reloads_address_part (ad, loc,
5090 base_reg_class (mode, as, MEM, SCRATCH),
5091 GET_MODE (ad), opnum, type, ind_levels);
5093 return ! removed_and;
5096 /* If we have an indexed stack slot, there are three possible reasons why
5097 it might be invalid: The index might need to be reloaded, the address
5098 might have been made by frame pointer elimination and hence have a
5099 constant out of range, or both reasons might apply.
5101 We can easily check for an index needing reload, but even if that is the
5102 case, we might also have an invalid constant. To avoid making the
5103 conservative assumption and requiring two reloads, we see if this address
5104 is valid when not interpreted strictly. If it is, the only problem is
5105 that the index needs a reload and find_reloads_address_1 will take care
5106 of it.
5108 Handle all base registers here, not just fp/ap/sp, because on some
5109 targets (namely SPARC) we can also get invalid addresses from preventive
5110 subreg big-endian corrections made by find_reloads_toplev. We
5111 can also get expressions involving LO_SUM (rather than PLUS) from
5112 find_reloads_subreg_address.
5114 If we decide to do something, it must be that `double_reg_address_ok'
5115 is true. We generate a reload of the base register + constant and
5116 rework the sum so that the reload register will be added to the index.
5117 This is safe because we know the address isn't shared.
5119 We check for the base register as both the first and second operand of
5120 the innermost PLUS and/or LO_SUM. */
5122 for (op_index = 0; op_index < 2; ++op_index)
5124 rtx operand, addend;
5125 enum rtx_code inner_code;
5127 if (GET_CODE (ad) != PLUS)
5128 continue;
5130 inner_code = GET_CODE (XEXP (ad, 0));
5131 if (!(GET_CODE (ad) == PLUS
5132 && CONST_INT_P (XEXP (ad, 1))
5133 && (inner_code == PLUS || inner_code == LO_SUM)))
5134 continue;
5136 operand = XEXP (XEXP (ad, 0), op_index);
5137 if (!REG_P (operand) || REGNO (operand) >= FIRST_PSEUDO_REGISTER)
5138 continue;
5140 addend = XEXP (XEXP (ad, 0), 1 - op_index);
5142 if ((regno_ok_for_base_p (REGNO (operand), mode, as, inner_code,
5143 GET_CODE (addend))
5144 || operand == frame_pointer_rtx
5145 || (!HARD_FRAME_POINTER_IS_FRAME_POINTER
5146 && operand == hard_frame_pointer_rtx)
5147 || (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5148 && operand == arg_pointer_rtx)
5149 || operand == stack_pointer_rtx)
5150 && ! maybe_memory_address_addr_space_p
5151 (mode, ad, as, &XEXP (XEXP (ad, 0), 1 - op_index)))
5153 rtx offset_reg;
5154 enum reg_class cls;
5156 offset_reg = plus_constant (GET_MODE (ad), operand,
5157 INTVAL (XEXP (ad, 1)));
5159 /* Form the adjusted address. */
5160 if (GET_CODE (XEXP (ad, 0)) == PLUS)
5161 ad = gen_rtx_PLUS (GET_MODE (ad),
5162 op_index == 0 ? offset_reg : addend,
5163 op_index == 0 ? addend : offset_reg);
5164 else
5165 ad = gen_rtx_LO_SUM (GET_MODE (ad),
5166 op_index == 0 ? offset_reg : addend,
5167 op_index == 0 ? addend : offset_reg);
5168 *loc = ad;
5170 cls = base_reg_class (mode, as, MEM, GET_CODE (addend));
5171 find_reloads_address_part (XEXP (ad, op_index),
5172 &XEXP (ad, op_index), cls,
5173 GET_MODE (ad), opnum, type, ind_levels);
5174 find_reloads_address_1 (mode, as,
5175 XEXP (ad, 1 - op_index), 1, GET_CODE (ad),
5176 GET_CODE (XEXP (ad, op_index)),
5177 &XEXP (ad, 1 - op_index), opnum,
5178 type, 0, insn);
5180 return 0;
5184 /* See if address becomes valid when an eliminable register
5185 in a sum is replaced. */
5187 tem = ad;
5188 if (GET_CODE (ad) == PLUS)
5189 tem = subst_indexed_address (ad);
5190 if (tem != ad && strict_memory_address_addr_space_p (mode, tem, as))
5192 /* Ok, we win that way. Replace any additional eliminable
5193 registers. */
5195 subst_reg_equivs_changed = 0;
5196 tem = subst_reg_equivs (tem, insn);
5198 /* Make sure that didn't make the address invalid again. */
5200 if (! subst_reg_equivs_changed
5201 || strict_memory_address_addr_space_p (mode, tem, as))
5203 *loc = tem;
5204 return 0;
5208 /* If constants aren't valid addresses, reload the constant address
5209 into a register. */
5210 if (CONSTANT_P (ad) && ! strict_memory_address_addr_space_p (mode, ad, as))
5212 machine_mode address_mode = GET_MODE (ad);
5213 if (address_mode == VOIDmode)
5214 address_mode = targetm.addr_space.address_mode (as);
5216 /* If AD is an address in the constant pool, the MEM rtx may be shared.
5217 Unshare it so we can safely alter it. */
5218 if (memrefloc && GET_CODE (ad) == SYMBOL_REF
5219 && CONSTANT_POOL_ADDRESS_P (ad))
5221 *memrefloc = copy_rtx (*memrefloc);
5222 loc = &XEXP (*memrefloc, 0);
5223 if (removed_and)
5224 loc = &XEXP (*loc, 0);
5227 find_reloads_address_part (ad, loc,
5228 base_reg_class (mode, as, MEM, SCRATCH),
5229 address_mode, opnum, type, ind_levels);
5230 return ! removed_and;
5233 return find_reloads_address_1 (mode, as, ad, 0, MEM, SCRATCH, loc,
5234 opnum, type, ind_levels, insn);
5237 /* Find all pseudo regs appearing in AD
5238 that are eliminable in favor of equivalent values
5239 and do not have hard regs; replace them by their equivalents.
5240 INSN, if nonzero, is the insn in which we do the reload. We put USEs in
5241 front of it for pseudos that we have to replace with stack slots. */
5243 static rtx
5244 subst_reg_equivs (rtx ad, rtx_insn *insn)
5246 RTX_CODE code = GET_CODE (ad);
5247 int i;
5248 const char *fmt;
5250 switch (code)
5252 case HIGH:
5253 case CONST:
5254 CASE_CONST_ANY:
5255 case SYMBOL_REF:
5256 case LABEL_REF:
5257 case PC:
5258 case CC0:
5259 return ad;
5261 case REG:
5263 int regno = REGNO (ad);
5265 if (reg_equiv_constant (regno) != 0)
5267 subst_reg_equivs_changed = 1;
5268 return reg_equiv_constant (regno);
5270 if (reg_equiv_memory_loc (regno) && num_not_at_initial_offset)
5272 rtx mem = make_memloc (ad, regno);
5273 if (! rtx_equal_p (mem, reg_equiv_mem (regno)))
5275 subst_reg_equivs_changed = 1;
5276 /* We mark the USE with QImode so that we recognize it
5277 as one that can be safely deleted at the end of
5278 reload. */
5279 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, ad), insn),
5280 QImode);
5281 return mem;
5285 return ad;
5287 case PLUS:
5288 /* Quickly dispose of a common case. */
5289 if (XEXP (ad, 0) == frame_pointer_rtx
5290 && CONST_INT_P (XEXP (ad, 1)))
5291 return ad;
5292 break;
5294 default:
5295 break;
5298 fmt = GET_RTX_FORMAT (code);
5299 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
5300 if (fmt[i] == 'e')
5301 XEXP (ad, i) = subst_reg_equivs (XEXP (ad, i), insn);
5302 return ad;
5305 /* Compute the sum of X and Y, making canonicalizations assumed in an
5306 address, namely: sum constant integers, surround the sum of two
5307 constants with a CONST, put the constant as the second operand, and
5308 group the constant on the outermost sum.
5310 This routine assumes both inputs are already in canonical form. */
5313 form_sum (machine_mode mode, rtx x, rtx y)
5315 rtx tem;
5317 gcc_assert (GET_MODE (x) == mode || GET_MODE (x) == VOIDmode);
5318 gcc_assert (GET_MODE (y) == mode || GET_MODE (y) == VOIDmode);
5320 if (CONST_INT_P (x))
5321 return plus_constant (mode, y, INTVAL (x));
5322 else if (CONST_INT_P (y))
5323 return plus_constant (mode, x, INTVAL (y));
5324 else if (CONSTANT_P (x))
5325 tem = x, x = y, y = tem;
5327 if (GET_CODE (x) == PLUS && CONSTANT_P (XEXP (x, 1)))
5328 return form_sum (mode, XEXP (x, 0), form_sum (mode, XEXP (x, 1), y));
5330 /* Note that if the operands of Y are specified in the opposite
5331 order in the recursive calls below, infinite recursion will occur. */
5332 if (GET_CODE (y) == PLUS && CONSTANT_P (XEXP (y, 1)))
5333 return form_sum (mode, form_sum (mode, x, XEXP (y, 0)), XEXP (y, 1));
5335 /* If both constant, encapsulate sum. Otherwise, just form sum. A
5336 constant will have been placed second. */
5337 if (CONSTANT_P (x) && CONSTANT_P (y))
5339 if (GET_CODE (x) == CONST)
5340 x = XEXP (x, 0);
5341 if (GET_CODE (y) == CONST)
5342 y = XEXP (y, 0);
5344 return gen_rtx_CONST (VOIDmode, gen_rtx_PLUS (mode, x, y));
5347 return gen_rtx_PLUS (mode, x, y);
5350 /* If ADDR is a sum containing a pseudo register that should be
5351 replaced with a constant (from reg_equiv_constant),
5352 return the result of doing so, and also apply the associative
5353 law so that the result is more likely to be a valid address.
5354 (But it is not guaranteed to be one.)
5356 Note that at most one register is replaced, even if more are
5357 replaceable. Also, we try to put the result into a canonical form
5358 so it is more likely to be a valid address.
5360 In all other cases, return ADDR. */
5362 static rtx
5363 subst_indexed_address (rtx addr)
5365 rtx op0 = 0, op1 = 0, op2 = 0;
5366 rtx tem;
5367 int regno;
5369 if (GET_CODE (addr) == PLUS)
5371 /* Try to find a register to replace. */
5372 op0 = XEXP (addr, 0), op1 = XEXP (addr, 1), op2 = 0;
5373 if (REG_P (op0)
5374 && (regno = REGNO (op0)) >= FIRST_PSEUDO_REGISTER
5375 && reg_renumber[regno] < 0
5376 && reg_equiv_constant (regno) != 0)
5377 op0 = reg_equiv_constant (regno);
5378 else if (REG_P (op1)
5379 && (regno = REGNO (op1)) >= FIRST_PSEUDO_REGISTER
5380 && reg_renumber[regno] < 0
5381 && reg_equiv_constant (regno) != 0)
5382 op1 = reg_equiv_constant (regno);
5383 else if (GET_CODE (op0) == PLUS
5384 && (tem = subst_indexed_address (op0)) != op0)
5385 op0 = tem;
5386 else if (GET_CODE (op1) == PLUS
5387 && (tem = subst_indexed_address (op1)) != op1)
5388 op1 = tem;
5389 else
5390 return addr;
5392 /* Pick out up to three things to add. */
5393 if (GET_CODE (op1) == PLUS)
5394 op2 = XEXP (op1, 1), op1 = XEXP (op1, 0);
5395 else if (GET_CODE (op0) == PLUS)
5396 op2 = op1, op1 = XEXP (op0, 1), op0 = XEXP (op0, 0);
5398 /* Compute the sum. */
5399 if (op2 != 0)
5400 op1 = form_sum (GET_MODE (addr), op1, op2);
5401 if (op1 != 0)
5402 op0 = form_sum (GET_MODE (addr), op0, op1);
5404 return op0;
5406 return addr;
5409 /* Update the REG_INC notes for an insn. It updates all REG_INC
5410 notes for the instruction which refer to REGNO the to refer
5411 to the reload number.
5413 INSN is the insn for which any REG_INC notes need updating.
5415 REGNO is the register number which has been reloaded.
5417 RELOADNUM is the reload number. */
5419 static void
5420 update_auto_inc_notes (rtx_insn *insn ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED,
5421 int reloadnum ATTRIBUTE_UNUSED)
5423 if (!AUTO_INC_DEC)
5424 return;
5426 for (rtx link = REG_NOTES (insn); link; link = XEXP (link, 1))
5427 if (REG_NOTE_KIND (link) == REG_INC
5428 && (int) REGNO (XEXP (link, 0)) == regno)
5429 push_replacement (&XEXP (link, 0), reloadnum, VOIDmode);
5432 /* Record the pseudo registers we must reload into hard registers in a
5433 subexpression of a would-be memory address, X referring to a value
5434 in mode MODE. (This function is not called if the address we find
5435 is strictly valid.)
5437 CONTEXT = 1 means we are considering regs as index regs,
5438 = 0 means we are considering them as base regs.
5439 OUTER_CODE is the code of the enclosing RTX, typically a MEM, a PLUS,
5440 or an autoinc code.
5441 If CONTEXT == 0 and OUTER_CODE is a PLUS or LO_SUM, then INDEX_CODE
5442 is the code of the index part of the address. Otherwise, pass SCRATCH
5443 for this argument.
5444 OPNUM and TYPE specify the purpose of any reloads made.
5446 IND_LEVELS says how many levels of indirect addressing are
5447 supported at this point in the address.
5449 INSN, if nonzero, is the insn in which we do the reload. It is used
5450 to determine if we may generate output reloads.
5452 We return nonzero if X, as a whole, is reloaded or replaced. */
5454 /* Note that we take shortcuts assuming that no multi-reg machine mode
5455 occurs as part of an address.
5456 Also, this is not fully machine-customizable; it works for machines
5457 such as VAXen and 68000's and 32000's, but other possible machines
5458 could have addressing modes that this does not handle right.
5459 If you add push_reload calls here, you need to make sure gen_reload
5460 handles those cases gracefully. */
5462 static int
5463 find_reloads_address_1 (machine_mode mode, addr_space_t as,
5464 rtx x, int context,
5465 enum rtx_code outer_code, enum rtx_code index_code,
5466 rtx *loc, int opnum, enum reload_type type,
5467 int ind_levels, rtx_insn *insn)
5469 #define REG_OK_FOR_CONTEXT(CONTEXT, REGNO, MODE, AS, OUTER, INDEX) \
5470 ((CONTEXT) == 0 \
5471 ? regno_ok_for_base_p (REGNO, MODE, AS, OUTER, INDEX) \
5472 : REGNO_OK_FOR_INDEX_P (REGNO))
5474 enum reg_class context_reg_class;
5475 RTX_CODE code = GET_CODE (x);
5476 bool reloaded_inner_of_autoinc = false;
5478 if (context == 1)
5479 context_reg_class = INDEX_REG_CLASS;
5480 else
5481 context_reg_class = base_reg_class (mode, as, outer_code, index_code);
5483 switch (code)
5485 case PLUS:
5487 rtx orig_op0 = XEXP (x, 0);
5488 rtx orig_op1 = XEXP (x, 1);
5489 RTX_CODE code0 = GET_CODE (orig_op0);
5490 RTX_CODE code1 = GET_CODE (orig_op1);
5491 rtx op0 = orig_op0;
5492 rtx op1 = orig_op1;
5494 if (GET_CODE (op0) == SUBREG)
5496 op0 = SUBREG_REG (op0);
5497 code0 = GET_CODE (op0);
5498 if (code0 == REG && REGNO (op0) < FIRST_PSEUDO_REGISTER)
5499 op0 = gen_rtx_REG (word_mode,
5500 (REGNO (op0) +
5501 subreg_regno_offset (REGNO (SUBREG_REG (orig_op0)),
5502 GET_MODE (SUBREG_REG (orig_op0)),
5503 SUBREG_BYTE (orig_op0),
5504 GET_MODE (orig_op0))));
5507 if (GET_CODE (op1) == SUBREG)
5509 op1 = SUBREG_REG (op1);
5510 code1 = GET_CODE (op1);
5511 if (code1 == REG && REGNO (op1) < FIRST_PSEUDO_REGISTER)
5512 /* ??? Why is this given op1's mode and above for
5513 ??? op0 SUBREGs we use word_mode? */
5514 op1 = gen_rtx_REG (GET_MODE (op1),
5515 (REGNO (op1) +
5516 subreg_regno_offset (REGNO (SUBREG_REG (orig_op1)),
5517 GET_MODE (SUBREG_REG (orig_op1)),
5518 SUBREG_BYTE (orig_op1),
5519 GET_MODE (orig_op1))));
5521 /* Plus in the index register may be created only as a result of
5522 register rematerialization for expression like &localvar*4. Reload it.
5523 It may be possible to combine the displacement on the outer level,
5524 but it is probably not worthwhile to do so. */
5525 if (context == 1)
5527 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5528 opnum, ADDR_TYPE (type), ind_levels, insn);
5529 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5530 context_reg_class,
5531 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5532 return 1;
5535 if (code0 == MULT || code0 == SIGN_EXTEND || code0 == TRUNCATE
5536 || code0 == ZERO_EXTEND || code1 == MEM)
5538 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5539 &XEXP (x, 0), opnum, type, ind_levels,
5540 insn);
5541 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, code0,
5542 &XEXP (x, 1), opnum, type, ind_levels,
5543 insn);
5546 else if (code1 == MULT || code1 == SIGN_EXTEND || code1 == TRUNCATE
5547 || code1 == ZERO_EXTEND || code0 == MEM)
5549 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, code1,
5550 &XEXP (x, 0), opnum, type, ind_levels,
5551 insn);
5552 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5553 &XEXP (x, 1), opnum, type, ind_levels,
5554 insn);
5557 else if (code0 == CONST_INT || code0 == CONST
5558 || code0 == SYMBOL_REF || code0 == LABEL_REF)
5559 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, code0,
5560 &XEXP (x, 1), opnum, type, ind_levels,
5561 insn);
5563 else if (code1 == CONST_INT || code1 == CONST
5564 || code1 == SYMBOL_REF || code1 == LABEL_REF)
5565 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, code1,
5566 &XEXP (x, 0), opnum, type, ind_levels,
5567 insn);
5569 else if (code0 == REG && code1 == REG)
5571 if (REGNO_OK_FOR_INDEX_P (REGNO (op1))
5572 && regno_ok_for_base_p (REGNO (op0), mode, as, PLUS, REG))
5573 return 0;
5574 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0))
5575 && regno_ok_for_base_p (REGNO (op1), mode, as, PLUS, REG))
5576 return 0;
5577 else if (regno_ok_for_base_p (REGNO (op0), mode, as, PLUS, REG))
5578 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5579 &XEXP (x, 1), opnum, type, ind_levels,
5580 insn);
5581 else if (REGNO_OK_FOR_INDEX_P (REGNO (op1)))
5582 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5583 &XEXP (x, 0), opnum, type, ind_levels,
5584 insn);
5585 else if (regno_ok_for_base_p (REGNO (op1), mode, as, PLUS, REG))
5586 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5587 &XEXP (x, 0), opnum, type, ind_levels,
5588 insn);
5589 else if (REGNO_OK_FOR_INDEX_P (REGNO (op0)))
5590 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, REG,
5591 &XEXP (x, 1), opnum, type, ind_levels,
5592 insn);
5593 else
5595 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5596 &XEXP (x, 0), opnum, type, ind_levels,
5597 insn);
5598 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5599 &XEXP (x, 1), opnum, type, ind_levels,
5600 insn);
5604 else if (code0 == REG)
5606 find_reloads_address_1 (mode, as, orig_op0, 1, PLUS, SCRATCH,
5607 &XEXP (x, 0), opnum, type, ind_levels,
5608 insn);
5609 find_reloads_address_1 (mode, as, orig_op1, 0, PLUS, REG,
5610 &XEXP (x, 1), opnum, type, ind_levels,
5611 insn);
5614 else if (code1 == REG)
5616 find_reloads_address_1 (mode, as, orig_op1, 1, PLUS, SCRATCH,
5617 &XEXP (x, 1), opnum, type, ind_levels,
5618 insn);
5619 find_reloads_address_1 (mode, as, orig_op0, 0, PLUS, REG,
5620 &XEXP (x, 0), opnum, type, ind_levels,
5621 insn);
5625 return 0;
5627 case POST_MODIFY:
5628 case PRE_MODIFY:
5630 rtx op0 = XEXP (x, 0);
5631 rtx op1 = XEXP (x, 1);
5632 enum rtx_code index_code;
5633 int regno;
5634 int reloadnum;
5636 if (GET_CODE (op1) != PLUS && GET_CODE (op1) != MINUS)
5637 return 0;
5639 /* Currently, we only support {PRE,POST}_MODIFY constructs
5640 where a base register is {inc,dec}remented by the contents
5641 of another register or by a constant value. Thus, these
5642 operands must match. */
5643 gcc_assert (op0 == XEXP (op1, 0));
5645 /* Require index register (or constant). Let's just handle the
5646 register case in the meantime... If the target allows
5647 auto-modify by a constant then we could try replacing a pseudo
5648 register with its equivalent constant where applicable.
5650 We also handle the case where the register was eliminated
5651 resulting in a PLUS subexpression.
5653 If we later decide to reload the whole PRE_MODIFY or
5654 POST_MODIFY, inc_for_reload might clobber the reload register
5655 before reading the index. The index register might therefore
5656 need to live longer than a TYPE reload normally would, so be
5657 conservative and class it as RELOAD_OTHER. */
5658 if ((REG_P (XEXP (op1, 1))
5659 && !REGNO_OK_FOR_INDEX_P (REGNO (XEXP (op1, 1))))
5660 || GET_CODE (XEXP (op1, 1)) == PLUS)
5661 find_reloads_address_1 (mode, as, XEXP (op1, 1), 1, code, SCRATCH,
5662 &XEXP (op1, 1), opnum, RELOAD_OTHER,
5663 ind_levels, insn);
5665 gcc_assert (REG_P (XEXP (op1, 0)));
5667 regno = REGNO (XEXP (op1, 0));
5668 index_code = GET_CODE (XEXP (op1, 1));
5670 /* A register that is incremented cannot be constant! */
5671 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5672 || reg_equiv_constant (regno) == 0);
5674 /* Handle a register that is equivalent to a memory location
5675 which cannot be addressed directly. */
5676 if (reg_equiv_memory_loc (regno) != 0
5677 && (reg_equiv_address (regno) != 0
5678 || num_not_at_initial_offset))
5680 rtx tem = make_memloc (XEXP (x, 0), regno);
5682 if (reg_equiv_address (regno)
5683 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5685 rtx orig = tem;
5687 /* First reload the memory location's address.
5688 We can't use ADDR_TYPE (type) here, because we need to
5689 write back the value after reading it, hence we actually
5690 need two registers. */
5691 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5692 &XEXP (tem, 0), opnum,
5693 RELOAD_OTHER,
5694 ind_levels, insn);
5696 if (!rtx_equal_p (tem, orig))
5697 push_reg_equiv_alt_mem (regno, tem);
5699 /* Then reload the memory location into a base
5700 register. */
5701 reloadnum = push_reload (tem, tem, &XEXP (x, 0),
5702 &XEXP (op1, 0),
5703 base_reg_class (mode, as,
5704 code, index_code),
5705 GET_MODE (x), GET_MODE (x), 0,
5706 0, opnum, RELOAD_OTHER);
5708 update_auto_inc_notes (this_insn, regno, reloadnum);
5709 return 0;
5713 if (reg_renumber[regno] >= 0)
5714 regno = reg_renumber[regno];
5716 /* We require a base register here... */
5717 if (!regno_ok_for_base_p (regno, GET_MODE (x), as, code, index_code))
5719 reloadnum = push_reload (XEXP (op1, 0), XEXP (x, 0),
5720 &XEXP (op1, 0), &XEXP (x, 0),
5721 base_reg_class (mode, as,
5722 code, index_code),
5723 GET_MODE (x), GET_MODE (x), 0, 0,
5724 opnum, RELOAD_OTHER);
5726 update_auto_inc_notes (this_insn, regno, reloadnum);
5727 return 0;
5730 return 0;
5732 case POST_INC:
5733 case POST_DEC:
5734 case PRE_INC:
5735 case PRE_DEC:
5736 if (REG_P (XEXP (x, 0)))
5738 int regno = REGNO (XEXP (x, 0));
5739 int value = 0;
5740 rtx x_orig = x;
5742 /* A register that is incremented cannot be constant! */
5743 gcc_assert (regno < FIRST_PSEUDO_REGISTER
5744 || reg_equiv_constant (regno) == 0);
5746 /* Handle a register that is equivalent to a memory location
5747 which cannot be addressed directly. */
5748 if (reg_equiv_memory_loc (regno) != 0
5749 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
5751 rtx tem = make_memloc (XEXP (x, 0), regno);
5752 if (reg_equiv_address (regno)
5753 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5755 rtx orig = tem;
5757 /* First reload the memory location's address.
5758 We can't use ADDR_TYPE (type) here, because we need to
5759 write back the value after reading it, hence we actually
5760 need two registers. */
5761 find_reloads_address (GET_MODE (tem), &tem, XEXP (tem, 0),
5762 &XEXP (tem, 0), opnum, type,
5763 ind_levels, insn);
5764 reloaded_inner_of_autoinc = true;
5765 if (!rtx_equal_p (tem, orig))
5766 push_reg_equiv_alt_mem (regno, tem);
5767 /* Put this inside a new increment-expression. */
5768 x = gen_rtx_fmt_e (GET_CODE (x), GET_MODE (x), tem);
5769 /* Proceed to reload that, as if it contained a register. */
5773 /* If we have a hard register that is ok in this incdec context,
5774 don't make a reload. If the register isn't nice enough for
5775 autoincdec, we can reload it. But, if an autoincrement of a
5776 register that we here verified as playing nice, still outside
5777 isn't "valid", it must be that no autoincrement is "valid".
5778 If that is true and something made an autoincrement anyway,
5779 this must be a special context where one is allowed.
5780 (For example, a "push" instruction.)
5781 We can't improve this address, so leave it alone. */
5783 /* Otherwise, reload the autoincrement into a suitable hard reg
5784 and record how much to increment by. */
5786 if (reg_renumber[regno] >= 0)
5787 regno = reg_renumber[regno];
5788 if (regno >= FIRST_PSEUDO_REGISTER
5789 || !REG_OK_FOR_CONTEXT (context, regno, mode, as, code,
5790 index_code))
5792 int reloadnum;
5794 /* If we can output the register afterwards, do so, this
5795 saves the extra update.
5796 We can do so if we have an INSN - i.e. no JUMP_INSN nor
5797 CALL_INSN - and it does not set CC0.
5798 But don't do this if we cannot directly address the
5799 memory location, since this will make it harder to
5800 reuse address reloads, and increases register pressure.
5801 Also don't do this if we can probably update x directly. */
5802 rtx equiv = (MEM_P (XEXP (x, 0))
5803 ? XEXP (x, 0)
5804 : reg_equiv_mem (regno));
5805 enum insn_code icode = optab_handler (add_optab, GET_MODE (x));
5806 if (insn && NONJUMP_INSN_P (insn)
5807 #if HAVE_cc0
5808 && ! sets_cc0_p (PATTERN (insn))
5809 #endif
5810 && (regno < FIRST_PSEUDO_REGISTER
5811 || (equiv
5812 && memory_operand (equiv, GET_MODE (equiv))
5813 && ! (icode != CODE_FOR_nothing
5814 && insn_operand_matches (icode, 0, equiv)
5815 && insn_operand_matches (icode, 1, equiv))))
5816 /* Using RELOAD_OTHER means we emit this and the reload we
5817 made earlier in the wrong order. */
5818 && !reloaded_inner_of_autoinc)
5820 /* We use the original pseudo for loc, so that
5821 emit_reload_insns() knows which pseudo this
5822 reload refers to and updates the pseudo rtx, not
5823 its equivalent memory location, as well as the
5824 corresponding entry in reg_last_reload_reg. */
5825 loc = &XEXP (x_orig, 0);
5826 x = XEXP (x, 0);
5827 reloadnum
5828 = push_reload (x, x, loc, loc,
5829 context_reg_class,
5830 GET_MODE (x), GET_MODE (x), 0, 0,
5831 opnum, RELOAD_OTHER);
5833 else
5835 reloadnum
5836 = push_reload (x, x, loc, (rtx*) 0,
5837 context_reg_class,
5838 GET_MODE (x), GET_MODE (x), 0, 0,
5839 opnum, type);
5840 rld[reloadnum].inc
5841 = find_inc_amount (PATTERN (this_insn), XEXP (x_orig, 0));
5843 value = 1;
5846 update_auto_inc_notes (this_insn, REGNO (XEXP (x_orig, 0)),
5847 reloadnum);
5849 return value;
5851 return 0;
5853 case TRUNCATE:
5854 case SIGN_EXTEND:
5855 case ZERO_EXTEND:
5856 /* Look for parts to reload in the inner expression and reload them
5857 too, in addition to this operation. Reloading all inner parts in
5858 addition to this one shouldn't be necessary, but at this point,
5859 we don't know if we can possibly omit any part that *can* be
5860 reloaded. Targets that are better off reloading just either part
5861 (or perhaps even a different part of an outer expression), should
5862 define LEGITIMIZE_RELOAD_ADDRESS. */
5863 find_reloads_address_1 (GET_MODE (XEXP (x, 0)), as, XEXP (x, 0),
5864 context, code, SCRATCH, &XEXP (x, 0), opnum,
5865 type, ind_levels, insn);
5866 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5867 context_reg_class,
5868 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5869 return 1;
5871 case MEM:
5872 /* This is probably the result of a substitution, by eliminate_regs, of
5873 an equivalent address for a pseudo that was not allocated to a hard
5874 register. Verify that the specified address is valid and reload it
5875 into a register.
5877 Since we know we are going to reload this item, don't decrement for
5878 the indirection level.
5880 Note that this is actually conservative: it would be slightly more
5881 efficient to use the value of SPILL_INDIRECT_LEVELS from
5882 reload1.c here. */
5884 find_reloads_address (GET_MODE (x), loc, XEXP (x, 0), &XEXP (x, 0),
5885 opnum, ADDR_TYPE (type), ind_levels, insn);
5886 push_reload (*loc, NULL_RTX, loc, (rtx*) 0,
5887 context_reg_class,
5888 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5889 return 1;
5891 case REG:
5893 int regno = REGNO (x);
5895 if (reg_equiv_constant (regno) != 0)
5897 find_reloads_address_part (reg_equiv_constant (regno), loc,
5898 context_reg_class,
5899 GET_MODE (x), opnum, type, ind_levels);
5900 return 1;
5903 #if 0 /* This might screw code in reload1.c to delete prior output-reload
5904 that feeds this insn. */
5905 if (reg_equiv_mem (regno) != 0)
5907 push_reload (reg_equiv_mem (regno), NULL_RTX, loc, (rtx*) 0,
5908 context_reg_class,
5909 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5910 return 1;
5912 #endif
5914 if (reg_equiv_memory_loc (regno)
5915 && (reg_equiv_address (regno) != 0 || num_not_at_initial_offset))
5917 rtx tem = make_memloc (x, regno);
5918 if (reg_equiv_address (regno) != 0
5919 || ! rtx_equal_p (tem, reg_equiv_mem (regno)))
5921 x = tem;
5922 find_reloads_address (GET_MODE (x), &x, XEXP (x, 0),
5923 &XEXP (x, 0), opnum, ADDR_TYPE (type),
5924 ind_levels, insn);
5925 if (!rtx_equal_p (x, tem))
5926 push_reg_equiv_alt_mem (regno, x);
5930 if (reg_renumber[regno] >= 0)
5931 regno = reg_renumber[regno];
5933 if (regno >= FIRST_PSEUDO_REGISTER
5934 || !REG_OK_FOR_CONTEXT (context, regno, mode, as, outer_code,
5935 index_code))
5937 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5938 context_reg_class,
5939 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5940 return 1;
5943 /* If a register appearing in an address is the subject of a CLOBBER
5944 in this insn, reload it into some other register to be safe.
5945 The CLOBBER is supposed to make the register unavailable
5946 from before this insn to after it. */
5947 if (regno_clobbered_p (regno, this_insn, GET_MODE (x), 0))
5949 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5950 context_reg_class,
5951 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5952 return 1;
5955 return 0;
5957 case SUBREG:
5958 if (REG_P (SUBREG_REG (x)))
5960 /* If this is a SUBREG of a hard register and the resulting register
5961 is of the wrong class, reload the whole SUBREG. This avoids
5962 needless copies if SUBREG_REG is multi-word. */
5963 if (REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
5965 int regno ATTRIBUTE_UNUSED = subreg_regno (x);
5967 if (!REG_OK_FOR_CONTEXT (context, regno, mode, as, outer_code,
5968 index_code))
5970 push_reload (x, NULL_RTX, loc, (rtx*) 0,
5971 context_reg_class,
5972 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
5973 return 1;
5976 /* If this is a SUBREG of a pseudo-register, and the pseudo-register
5977 is larger than the class size, then reload the whole SUBREG. */
5978 else
5980 enum reg_class rclass = context_reg_class;
5981 if (ira_reg_class_max_nregs [rclass][GET_MODE (SUBREG_REG (x))]
5982 > reg_class_size[(int) rclass])
5984 /* If the inner register will be replaced by a memory
5985 reference, we can do this only if we can replace the
5986 whole subreg by a (narrower) memory reference. If
5987 this is not possible, fall through and reload just
5988 the inner register (including address reloads). */
5989 if (reg_equiv_memory_loc (REGNO (SUBREG_REG (x))) != 0)
5991 rtx tem = find_reloads_subreg_address (x, opnum,
5992 ADDR_TYPE (type),
5993 ind_levels, insn,
5994 NULL);
5995 if (tem)
5997 push_reload (tem, NULL_RTX, loc, (rtx*) 0, rclass,
5998 GET_MODE (tem), VOIDmode, 0, 0,
5999 opnum, type);
6000 return 1;
6003 else
6005 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6006 GET_MODE (x), VOIDmode, 0, 0, opnum, type);
6007 return 1;
6012 break;
6014 default:
6015 break;
6019 const char *fmt = GET_RTX_FORMAT (code);
6020 int i;
6022 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6024 if (fmt[i] == 'e')
6025 /* Pass SCRATCH for INDEX_CODE, since CODE can never be a PLUS once
6026 we get here. */
6027 find_reloads_address_1 (mode, as, XEXP (x, i), context,
6028 code, SCRATCH, &XEXP (x, i),
6029 opnum, type, ind_levels, insn);
6033 #undef REG_OK_FOR_CONTEXT
6034 return 0;
6037 /* X, which is found at *LOC, is a part of an address that needs to be
6038 reloaded into a register of class RCLASS. If X is a constant, or if
6039 X is a PLUS that contains a constant, check that the constant is a
6040 legitimate operand and that we are supposed to be able to load
6041 it into the register.
6043 If not, force the constant into memory and reload the MEM instead.
6045 MODE is the mode to use, in case X is an integer constant.
6047 OPNUM and TYPE describe the purpose of any reloads made.
6049 IND_LEVELS says how many levels of indirect addressing this machine
6050 supports. */
6052 static void
6053 find_reloads_address_part (rtx x, rtx *loc, enum reg_class rclass,
6054 machine_mode mode, int opnum,
6055 enum reload_type type, int ind_levels)
6057 if (CONSTANT_P (x)
6058 && (!targetm.legitimate_constant_p (mode, x)
6059 || targetm.preferred_reload_class (x, rclass) == NO_REGS))
6061 x = force_const_mem (mode, x);
6062 find_reloads_address (mode, &x, XEXP (x, 0), &XEXP (x, 0),
6063 opnum, type, ind_levels, 0);
6066 else if (GET_CODE (x) == PLUS
6067 && CONSTANT_P (XEXP (x, 1))
6068 && (!targetm.legitimate_constant_p (GET_MODE (x), XEXP (x, 1))
6069 || targetm.preferred_reload_class (XEXP (x, 1), rclass)
6070 == NO_REGS))
6072 rtx tem;
6074 tem = force_const_mem (GET_MODE (x), XEXP (x, 1));
6075 x = gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), tem);
6076 find_reloads_address (mode, &XEXP (x, 1), XEXP (tem, 0), &XEXP (tem, 0),
6077 opnum, type, ind_levels, 0);
6080 push_reload (x, NULL_RTX, loc, (rtx*) 0, rclass,
6081 mode, VOIDmode, 0, 0, opnum, type);
6084 /* X, a subreg of a pseudo, is a part of an address that needs to be
6085 reloaded, and the pseusdo is equivalent to a memory location.
6087 Attempt to replace the whole subreg by a (possibly narrower or wider)
6088 memory reference. If this is possible, return this new memory
6089 reference, and push all required address reloads. Otherwise,
6090 return NULL.
6092 OPNUM and TYPE identify the purpose of the reload.
6094 IND_LEVELS says how many levels of indirect addressing are
6095 supported at this point in the address.
6097 INSN, if nonzero, is the insn in which we do the reload. It is used
6098 to determine where to put USEs for pseudos that we have to replace with
6099 stack slots. */
6101 static rtx
6102 find_reloads_subreg_address (rtx x, int opnum, enum reload_type type,
6103 int ind_levels, rtx_insn *insn,
6104 int *address_reloaded)
6106 machine_mode outer_mode = GET_MODE (x);
6107 machine_mode inner_mode = GET_MODE (SUBREG_REG (x));
6108 int regno = REGNO (SUBREG_REG (x));
6109 int reloaded = 0;
6110 rtx tem, orig;
6111 poly_int64 offset;
6113 gcc_assert (reg_equiv_memory_loc (regno) != 0);
6115 /* We cannot replace the subreg with a modified memory reference if:
6117 - we have a paradoxical subreg that implicitly acts as a zero or
6118 sign extension operation due to LOAD_EXTEND_OP;
6120 - we have a subreg that is implicitly supposed to act on the full
6121 register due to WORD_REGISTER_OPERATIONS (see also eliminate_regs);
6123 - the address of the equivalent memory location is mode-dependent; or
6125 - we have a paradoxical subreg and the resulting memory is not
6126 sufficiently aligned to allow access in the wider mode.
6128 In addition, we choose not to perform the replacement for *any*
6129 paradoxical subreg, even if it were possible in principle. This
6130 is to avoid generating wider memory references than necessary.
6132 This corresponds to how previous versions of reload used to handle
6133 paradoxical subregs where no address reload was required. */
6135 if (paradoxical_subreg_p (x))
6136 return NULL;
6138 if (WORD_REGISTER_OPERATIONS
6139 && partial_subreg_p (outer_mode, inner_mode)
6140 && ((GET_MODE_SIZE (outer_mode) - 1) / UNITS_PER_WORD
6141 == (GET_MODE_SIZE (inner_mode) - 1) / UNITS_PER_WORD))
6142 return NULL;
6144 /* Since we don't attempt to handle paradoxical subregs, we can just
6145 call into simplify_subreg, which will handle all remaining checks
6146 for us. */
6147 orig = make_memloc (SUBREG_REG (x), regno);
6148 offset = SUBREG_BYTE (x);
6149 tem = simplify_subreg (outer_mode, orig, inner_mode, offset);
6150 if (!tem || !MEM_P (tem))
6151 return NULL;
6153 /* Now push all required address reloads, if any. */
6154 reloaded = find_reloads_address (GET_MODE (tem), &tem,
6155 XEXP (tem, 0), &XEXP (tem, 0),
6156 opnum, type, ind_levels, insn);
6157 /* ??? Do we need to handle nonzero offsets somehow? */
6158 if (known_eq (offset, 0) && !rtx_equal_p (tem, orig))
6159 push_reg_equiv_alt_mem (regno, tem);
6161 /* For some processors an address may be valid in the original mode but
6162 not in a smaller mode. For example, ARM accepts a scaled index register
6163 in SImode but not in HImode. Note that this is only a problem if the
6164 address in reg_equiv_mem is already invalid in the new mode; other
6165 cases would be fixed by find_reloads_address as usual.
6167 ??? We attempt to handle such cases here by doing an additional reload
6168 of the full address after the usual processing by find_reloads_address.
6169 Note that this may not work in the general case, but it seems to cover
6170 the cases where this situation currently occurs. A more general fix
6171 might be to reload the *value* instead of the address, but this would
6172 not be expected by the callers of this routine as-is.
6174 If find_reloads_address already completed replaced the address, there
6175 is nothing further to do. */
6176 if (reloaded == 0
6177 && reg_equiv_mem (regno) != 0
6178 && !strict_memory_address_addr_space_p
6179 (GET_MODE (x), XEXP (reg_equiv_mem (regno), 0),
6180 MEM_ADDR_SPACE (reg_equiv_mem (regno))))
6182 push_reload (XEXP (tem, 0), NULL_RTX, &XEXP (tem, 0), (rtx*) 0,
6183 base_reg_class (GET_MODE (tem), MEM_ADDR_SPACE (tem),
6184 MEM, SCRATCH),
6185 GET_MODE (XEXP (tem, 0)), VOIDmode, 0, 0, opnum, type);
6186 reloaded = 1;
6189 /* If this is not a toplevel operand, find_reloads doesn't see this
6190 substitution. We have to emit a USE of the pseudo so that
6191 delete_output_reload can see it. */
6192 if (replace_reloads && recog_data.operand[opnum] != x)
6193 /* We mark the USE with QImode so that we recognize it as one that
6194 can be safely deleted at the end of reload. */
6195 PUT_MODE (emit_insn_before (gen_rtx_USE (VOIDmode, SUBREG_REG (x)), insn),
6196 QImode);
6198 if (address_reloaded)
6199 *address_reloaded = reloaded;
6201 return tem;
6204 /* Substitute into the current INSN the registers into which we have reloaded
6205 the things that need reloading. The array `replacements'
6206 contains the locations of all pointers that must be changed
6207 and says what to replace them with.
6209 Return the rtx that X translates into; usually X, but modified. */
6211 void
6212 subst_reloads (rtx_insn *insn)
6214 int i;
6216 for (i = 0; i < n_replacements; i++)
6218 struct replacement *r = &replacements[i];
6219 rtx reloadreg = rld[r->what].reg_rtx;
6220 if (reloadreg)
6222 #ifdef DEBUG_RELOAD
6223 /* This checking takes a very long time on some platforms
6224 causing the gcc.c-torture/compile/limits-fnargs.c test
6225 to time out during testing. See PR 31850.
6227 Internal consistency test. Check that we don't modify
6228 anything in the equivalence arrays. Whenever something from
6229 those arrays needs to be reloaded, it must be unshared before
6230 being substituted into; the equivalence must not be modified.
6231 Otherwise, if the equivalence is used after that, it will
6232 have been modified, and the thing substituted (probably a
6233 register) is likely overwritten and not a usable equivalence. */
6234 int check_regno;
6236 for (check_regno = 0; check_regno < max_regno; check_regno++)
6238 #define CHECK_MODF(ARRAY) \
6239 gcc_assert (!(*reg_equivs)[check_regno].ARRAY \
6240 || !loc_mentioned_in_p (r->where, \
6241 (*reg_equivs)[check_regno].ARRAY))
6243 CHECK_MODF (constant);
6244 CHECK_MODF (memory_loc);
6245 CHECK_MODF (address);
6246 CHECK_MODF (mem);
6247 #undef CHECK_MODF
6249 #endif /* DEBUG_RELOAD */
6251 /* If we're replacing a LABEL_REF with a register, there must
6252 already be an indication (to e.g. flow) which label this
6253 register refers to. */
6254 gcc_assert (GET_CODE (*r->where) != LABEL_REF
6255 || !JUMP_P (insn)
6256 || find_reg_note (insn,
6257 REG_LABEL_OPERAND,
6258 XEXP (*r->where, 0))
6259 || label_is_jump_target_p (XEXP (*r->where, 0), insn));
6261 /* Encapsulate RELOADREG so its machine mode matches what
6262 used to be there. Note that gen_lowpart_common will
6263 do the wrong thing if RELOADREG is multi-word. RELOADREG
6264 will always be a REG here. */
6265 if (GET_MODE (reloadreg) != r->mode && r->mode != VOIDmode)
6266 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6268 *r->where = reloadreg;
6270 /* If reload got no reg and isn't optional, something's wrong. */
6271 else
6272 gcc_assert (rld[r->what].optional);
6276 /* Make a copy of any replacements being done into X and move those
6277 copies to locations in Y, a copy of X. */
6279 void
6280 copy_replacements (rtx x, rtx y)
6282 copy_replacements_1 (&x, &y, n_replacements);
6285 static void
6286 copy_replacements_1 (rtx *px, rtx *py, int orig_replacements)
6288 int i, j;
6289 rtx x, y;
6290 struct replacement *r;
6291 enum rtx_code code;
6292 const char *fmt;
6294 for (j = 0; j < orig_replacements; j++)
6295 if (replacements[j].where == px)
6297 r = &replacements[n_replacements++];
6298 r->where = py;
6299 r->what = replacements[j].what;
6300 r->mode = replacements[j].mode;
6303 x = *px;
6304 y = *py;
6305 code = GET_CODE (x);
6306 fmt = GET_RTX_FORMAT (code);
6308 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6310 if (fmt[i] == 'e')
6311 copy_replacements_1 (&XEXP (x, i), &XEXP (y, i), orig_replacements);
6312 else if (fmt[i] == 'E')
6313 for (j = XVECLEN (x, i); --j >= 0; )
6314 copy_replacements_1 (&XVECEXP (x, i, j), &XVECEXP (y, i, j),
6315 orig_replacements);
6319 /* Change any replacements being done to *X to be done to *Y. */
6321 void
6322 move_replacements (rtx *x, rtx *y)
6324 int i;
6326 for (i = 0; i < n_replacements; i++)
6327 if (replacements[i].where == x)
6328 replacements[i].where = y;
6331 /* If LOC was scheduled to be replaced by something, return the replacement.
6332 Otherwise, return *LOC. */
6335 find_replacement (rtx *loc)
6337 struct replacement *r;
6339 for (r = &replacements[0]; r < &replacements[n_replacements]; r++)
6341 rtx reloadreg = rld[r->what].reg_rtx;
6343 if (reloadreg && r->where == loc)
6345 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6346 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6348 return reloadreg;
6350 else if (reloadreg && GET_CODE (*loc) == SUBREG
6351 && r->where == &SUBREG_REG (*loc))
6353 if (r->mode != VOIDmode && GET_MODE (reloadreg) != r->mode)
6354 reloadreg = reload_adjust_reg_for_mode (reloadreg, r->mode);
6356 return simplify_gen_subreg (GET_MODE (*loc), reloadreg,
6357 GET_MODE (SUBREG_REG (*loc)),
6358 SUBREG_BYTE (*loc));
6362 /* If *LOC is a PLUS, MINUS, or MULT, see if a replacement is scheduled for
6363 what's inside and make a new rtl if so. */
6364 if (GET_CODE (*loc) == PLUS || GET_CODE (*loc) == MINUS
6365 || GET_CODE (*loc) == MULT)
6367 rtx x = find_replacement (&XEXP (*loc, 0));
6368 rtx y = find_replacement (&XEXP (*loc, 1));
6370 if (x != XEXP (*loc, 0) || y != XEXP (*loc, 1))
6371 return gen_rtx_fmt_ee (GET_CODE (*loc), GET_MODE (*loc), x, y);
6374 return *loc;
6377 /* Return nonzero if register in range [REGNO, ENDREGNO)
6378 appears either explicitly or implicitly in X
6379 other than being stored into (except for earlyclobber operands).
6381 References contained within the substructure at LOC do not count.
6382 LOC may be zero, meaning don't ignore anything.
6384 This is similar to refers_to_regno_p in rtlanal.c except that we
6385 look at equivalences for pseudos that didn't get hard registers. */
6387 static int
6388 refers_to_regno_for_reload_p (unsigned int regno, unsigned int endregno,
6389 rtx x, rtx *loc)
6391 int i;
6392 unsigned int r;
6393 RTX_CODE code;
6394 const char *fmt;
6396 if (x == 0)
6397 return 0;
6399 repeat:
6400 code = GET_CODE (x);
6402 switch (code)
6404 case REG:
6405 r = REGNO (x);
6407 /* If this is a pseudo, a hard register must not have been allocated.
6408 X must therefore either be a constant or be in memory. */
6409 if (r >= FIRST_PSEUDO_REGISTER)
6411 if (reg_equiv_memory_loc (r))
6412 return refers_to_regno_for_reload_p (regno, endregno,
6413 reg_equiv_memory_loc (r),
6414 (rtx*) 0);
6416 gcc_assert (reg_equiv_constant (r) || reg_equiv_invariant (r));
6417 return 0;
6420 return endregno > r && regno < END_REGNO (x);
6422 case SUBREG:
6423 /* If this is a SUBREG of a hard reg, we can see exactly which
6424 registers are being modified. Otherwise, handle normally. */
6425 if (REG_P (SUBREG_REG (x))
6426 && REGNO (SUBREG_REG (x)) < FIRST_PSEUDO_REGISTER)
6428 unsigned int inner_regno = subreg_regno (x);
6429 unsigned int inner_endregno
6430 = inner_regno + (inner_regno < FIRST_PSEUDO_REGISTER
6431 ? subreg_nregs (x) : 1);
6433 return endregno > inner_regno && regno < inner_endregno;
6435 break;
6437 case CLOBBER:
6438 case SET:
6439 if (&SET_DEST (x) != loc
6440 /* Note setting a SUBREG counts as referring to the REG it is in for
6441 a pseudo but not for hard registers since we can
6442 treat each word individually. */
6443 && ((GET_CODE (SET_DEST (x)) == SUBREG
6444 && loc != &SUBREG_REG (SET_DEST (x))
6445 && REG_P (SUBREG_REG (SET_DEST (x)))
6446 && REGNO (SUBREG_REG (SET_DEST (x))) >= FIRST_PSEUDO_REGISTER
6447 && refers_to_regno_for_reload_p (regno, endregno,
6448 SUBREG_REG (SET_DEST (x)),
6449 loc))
6450 /* If the output is an earlyclobber operand, this is
6451 a conflict. */
6452 || ((!REG_P (SET_DEST (x))
6453 || earlyclobber_operand_p (SET_DEST (x)))
6454 && refers_to_regno_for_reload_p (regno, endregno,
6455 SET_DEST (x), loc))))
6456 return 1;
6458 if (code == CLOBBER || loc == &SET_SRC (x))
6459 return 0;
6460 x = SET_SRC (x);
6461 goto repeat;
6463 default:
6464 break;
6467 /* X does not match, so try its subexpressions. */
6469 fmt = GET_RTX_FORMAT (code);
6470 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
6472 if (fmt[i] == 'e' && loc != &XEXP (x, i))
6474 if (i == 0)
6476 x = XEXP (x, 0);
6477 goto repeat;
6479 else
6480 if (refers_to_regno_for_reload_p (regno, endregno,
6481 XEXP (x, i), loc))
6482 return 1;
6484 else if (fmt[i] == 'E')
6486 int j;
6487 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
6488 if (loc != &XVECEXP (x, i, j)
6489 && refers_to_regno_for_reload_p (regno, endregno,
6490 XVECEXP (x, i, j), loc))
6491 return 1;
6494 return 0;
6497 /* Nonzero if modifying X will affect IN. If X is a register or a SUBREG,
6498 we check if any register number in X conflicts with the relevant register
6499 numbers. If X is a constant, return 0. If X is a MEM, return 1 iff IN
6500 contains a MEM (we don't bother checking for memory addresses that can't
6501 conflict because we expect this to be a rare case.
6503 This function is similar to reg_overlap_mentioned_p in rtlanal.c except
6504 that we look at equivalences for pseudos that didn't get hard registers. */
6507 reg_overlap_mentioned_for_reload_p (rtx x, rtx in)
6509 int regno, endregno;
6511 /* Overly conservative. */
6512 if (GET_CODE (x) == STRICT_LOW_PART
6513 || GET_RTX_CLASS (GET_CODE (x)) == RTX_AUTOINC)
6514 x = XEXP (x, 0);
6516 /* If either argument is a constant, then modifying X can not affect IN. */
6517 if (CONSTANT_P (x) || CONSTANT_P (in))
6518 return 0;
6519 else if (GET_CODE (x) == SUBREG && MEM_P (SUBREG_REG (x)))
6520 return refers_to_mem_for_reload_p (in);
6521 else if (GET_CODE (x) == SUBREG)
6523 regno = REGNO (SUBREG_REG (x));
6524 if (regno < FIRST_PSEUDO_REGISTER)
6525 regno += subreg_regno_offset (REGNO (SUBREG_REG (x)),
6526 GET_MODE (SUBREG_REG (x)),
6527 SUBREG_BYTE (x),
6528 GET_MODE (x));
6529 endregno = regno + (regno < FIRST_PSEUDO_REGISTER
6530 ? subreg_nregs (x) : 1);
6532 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6534 else if (REG_P (x))
6536 regno = REGNO (x);
6538 /* If this is a pseudo, it must not have been assigned a hard register.
6539 Therefore, it must either be in memory or be a constant. */
6541 if (regno >= FIRST_PSEUDO_REGISTER)
6543 if (reg_equiv_memory_loc (regno))
6544 return refers_to_mem_for_reload_p (in);
6545 gcc_assert (reg_equiv_constant (regno));
6546 return 0;
6549 endregno = END_REGNO (x);
6551 return refers_to_regno_for_reload_p (regno, endregno, in, (rtx*) 0);
6553 else if (MEM_P (x))
6554 return refers_to_mem_for_reload_p (in);
6555 else if (GET_CODE (x) == SCRATCH || GET_CODE (x) == PC
6556 || GET_CODE (x) == CC0)
6557 return reg_mentioned_p (x, in);
6558 else
6560 gcc_assert (GET_CODE (x) == PLUS);
6562 /* We actually want to know if X is mentioned somewhere inside IN.
6563 We must not say that (plus (sp) (const_int 124)) is in
6564 (plus (sp) (const_int 64)), since that can lead to incorrect reload
6565 allocation when spuriously changing a RELOAD_FOR_OUTPUT_ADDRESS
6566 into a RELOAD_OTHER on behalf of another RELOAD_OTHER. */
6567 while (MEM_P (in))
6568 in = XEXP (in, 0);
6569 if (REG_P (in))
6570 return 0;
6571 else if (GET_CODE (in) == PLUS)
6572 return (rtx_equal_p (x, in)
6573 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 0))
6574 || reg_overlap_mentioned_for_reload_p (x, XEXP (in, 1)));
6575 else return (reg_overlap_mentioned_for_reload_p (XEXP (x, 0), in)
6576 || reg_overlap_mentioned_for_reload_p (XEXP (x, 1), in));
6579 gcc_unreachable ();
6582 /* Return nonzero if anything in X contains a MEM. Look also for pseudo
6583 registers. */
6585 static int
6586 refers_to_mem_for_reload_p (rtx x)
6588 const char *fmt;
6589 int i;
6591 if (MEM_P (x))
6592 return 1;
6594 if (REG_P (x))
6595 return (REGNO (x) >= FIRST_PSEUDO_REGISTER
6596 && reg_equiv_memory_loc (REGNO (x)));
6598 fmt = GET_RTX_FORMAT (GET_CODE (x));
6599 for (i = GET_RTX_LENGTH (GET_CODE (x)) - 1; i >= 0; i--)
6600 if (fmt[i] == 'e'
6601 && (MEM_P (XEXP (x, i))
6602 || refers_to_mem_for_reload_p (XEXP (x, i))))
6603 return 1;
6605 return 0;
6608 /* Check the insns before INSN to see if there is a suitable register
6609 containing the same value as GOAL.
6610 If OTHER is -1, look for a register in class RCLASS.
6611 Otherwise, just see if register number OTHER shares GOAL's value.
6613 Return an rtx for the register found, or zero if none is found.
6615 If RELOAD_REG_P is (short *)1,
6616 we reject any hard reg that appears in reload_reg_rtx
6617 because such a hard reg is also needed coming into this insn.
6619 If RELOAD_REG_P is any other nonzero value,
6620 it is a vector indexed by hard reg number
6621 and we reject any hard reg whose element in the vector is nonnegative
6622 as well as any that appears in reload_reg_rtx.
6624 If GOAL is zero, then GOALREG is a register number; we look
6625 for an equivalent for that register.
6627 MODE is the machine mode of the value we want an equivalence for.
6628 If GOAL is nonzero and not VOIDmode, then it must have mode MODE.
6630 This function is used by jump.c as well as in the reload pass.
6632 If GOAL is the sum of the stack pointer and a constant, we treat it
6633 as if it were a constant except that sp is required to be unchanging. */
6636 find_equiv_reg (rtx goal, rtx_insn *insn, enum reg_class rclass, int other,
6637 short *reload_reg_p, int goalreg, machine_mode mode)
6639 rtx_insn *p = insn;
6640 rtx goaltry, valtry, value;
6641 rtx_insn *where;
6642 rtx pat;
6643 int regno = -1;
6644 int valueno;
6645 int goal_mem = 0;
6646 int goal_const = 0;
6647 int goal_mem_addr_varies = 0;
6648 int need_stable_sp = 0;
6649 int nregs;
6650 int valuenregs;
6651 int num = 0;
6653 if (goal == 0)
6654 regno = goalreg;
6655 else if (REG_P (goal))
6656 regno = REGNO (goal);
6657 else if (MEM_P (goal))
6659 enum rtx_code code = GET_CODE (XEXP (goal, 0));
6660 if (MEM_VOLATILE_P (goal))
6661 return 0;
6662 if (flag_float_store && SCALAR_FLOAT_MODE_P (GET_MODE (goal)))
6663 return 0;
6664 /* An address with side effects must be reexecuted. */
6665 switch (code)
6667 case POST_INC:
6668 case PRE_INC:
6669 case POST_DEC:
6670 case PRE_DEC:
6671 case POST_MODIFY:
6672 case PRE_MODIFY:
6673 return 0;
6674 default:
6675 break;
6677 goal_mem = 1;
6679 else if (CONSTANT_P (goal))
6680 goal_const = 1;
6681 else if (GET_CODE (goal) == PLUS
6682 && XEXP (goal, 0) == stack_pointer_rtx
6683 && CONSTANT_P (XEXP (goal, 1)))
6684 goal_const = need_stable_sp = 1;
6685 else if (GET_CODE (goal) == PLUS
6686 && XEXP (goal, 0) == frame_pointer_rtx
6687 && CONSTANT_P (XEXP (goal, 1)))
6688 goal_const = 1;
6689 else
6690 return 0;
6692 num = 0;
6693 /* Scan insns back from INSN, looking for one that copies
6694 a value into or out of GOAL.
6695 Stop and give up if we reach a label. */
6697 while (1)
6699 p = PREV_INSN (p);
6700 if (p && DEBUG_INSN_P (p))
6701 continue;
6702 num++;
6703 if (p == 0 || LABEL_P (p)
6704 || num > PARAM_VALUE (PARAM_MAX_RELOAD_SEARCH_INSNS))
6705 return 0;
6707 /* Don't reuse register contents from before a setjmp-type
6708 function call; on the second return (from the longjmp) it
6709 might have been clobbered by a later reuse. It doesn't
6710 seem worthwhile to actually go and see if it is actually
6711 reused even if that information would be readily available;
6712 just don't reuse it across the setjmp call. */
6713 if (CALL_P (p) && find_reg_note (p, REG_SETJMP, NULL_RTX))
6714 return 0;
6716 if (NONJUMP_INSN_P (p)
6717 /* If we don't want spill regs ... */
6718 && (! (reload_reg_p != 0
6719 && reload_reg_p != (short *) HOST_WIDE_INT_1)
6720 /* ... then ignore insns introduced by reload; they aren't
6721 useful and can cause results in reload_as_needed to be
6722 different from what they were when calculating the need for
6723 spills. If we notice an input-reload insn here, we will
6724 reject it below, but it might hide a usable equivalent.
6725 That makes bad code. It may even fail: perhaps no reg was
6726 spilled for this insn because it was assumed we would find
6727 that equivalent. */
6728 || INSN_UID (p) < reload_first_uid))
6730 rtx tem;
6731 pat = single_set (p);
6733 /* First check for something that sets some reg equal to GOAL. */
6734 if (pat != 0
6735 && ((regno >= 0
6736 && true_regnum (SET_SRC (pat)) == regno
6737 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6739 (regno >= 0
6740 && true_regnum (SET_DEST (pat)) == regno
6741 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0)
6743 (goal_const && rtx_equal_p (SET_SRC (pat), goal)
6744 /* When looking for stack pointer + const,
6745 make sure we don't use a stack adjust. */
6746 && !reg_overlap_mentioned_for_reload_p (SET_DEST (pat), goal)
6747 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0)
6748 || (goal_mem
6749 && (valueno = true_regnum (valtry = SET_DEST (pat))) >= 0
6750 && rtx_renumbered_equal_p (goal, SET_SRC (pat)))
6751 || (goal_mem
6752 && (valueno = true_regnum (valtry = SET_SRC (pat))) >= 0
6753 && rtx_renumbered_equal_p (goal, SET_DEST (pat)))
6754 /* If we are looking for a constant,
6755 and something equivalent to that constant was copied
6756 into a reg, we can use that reg. */
6757 || (goal_const && REG_NOTES (p) != 0
6758 && (tem = find_reg_note (p, REG_EQUIV, NULL_RTX))
6759 && ((rtx_equal_p (XEXP (tem, 0), goal)
6760 && (valueno
6761 = true_regnum (valtry = SET_DEST (pat))) >= 0)
6762 || (REG_P (SET_DEST (pat))
6763 && CONST_DOUBLE_AS_FLOAT_P (XEXP (tem, 0))
6764 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6765 && CONST_INT_P (goal)
6766 && (goaltry = operand_subword (XEXP (tem, 0), 0,
6767 0, VOIDmode)) != 0
6768 && rtx_equal_p (goal, goaltry)
6769 && (valtry
6770 = operand_subword (SET_DEST (pat), 0, 0,
6771 VOIDmode))
6772 && (valueno = true_regnum (valtry)) >= 0)))
6773 || (goal_const && (tem = find_reg_note (p, REG_EQUIV,
6774 NULL_RTX))
6775 && REG_P (SET_DEST (pat))
6776 && CONST_DOUBLE_AS_FLOAT_P (XEXP (tem, 0))
6777 && SCALAR_FLOAT_MODE_P (GET_MODE (XEXP (tem, 0)))
6778 && CONST_INT_P (goal)
6779 && (goaltry = operand_subword (XEXP (tem, 0), 1, 0,
6780 VOIDmode)) != 0
6781 && rtx_equal_p (goal, goaltry)
6782 && (valtry
6783 = operand_subword (SET_DEST (pat), 1, 0, VOIDmode))
6784 && (valueno = true_regnum (valtry)) >= 0)))
6786 if (other >= 0)
6788 if (valueno != other)
6789 continue;
6791 else if ((unsigned) valueno >= FIRST_PSEUDO_REGISTER)
6792 continue;
6793 else if (!in_hard_reg_set_p (reg_class_contents[(int) rclass],
6794 mode, valueno))
6795 continue;
6796 value = valtry;
6797 where = p;
6798 break;
6803 /* We found a previous insn copying GOAL into a suitable other reg VALUE
6804 (or copying VALUE into GOAL, if GOAL is also a register).
6805 Now verify that VALUE is really valid. */
6807 /* VALUENO is the register number of VALUE; a hard register. */
6809 /* Don't try to re-use something that is killed in this insn. We want
6810 to be able to trust REG_UNUSED notes. */
6811 if (REG_NOTES (where) != 0 && find_reg_note (where, REG_UNUSED, value))
6812 return 0;
6814 /* If we propose to get the value from the stack pointer or if GOAL is
6815 a MEM based on the stack pointer, we need a stable SP. */
6816 if (valueno == STACK_POINTER_REGNUM || regno == STACK_POINTER_REGNUM
6817 || (goal_mem && reg_overlap_mentioned_for_reload_p (stack_pointer_rtx,
6818 goal)))
6819 need_stable_sp = 1;
6821 /* Reject VALUE if the copy-insn moved the wrong sort of datum. */
6822 if (GET_MODE (value) != mode)
6823 return 0;
6825 /* Reject VALUE if it was loaded from GOAL
6826 and is also a register that appears in the address of GOAL. */
6828 if (goal_mem && value == SET_DEST (single_set (where))
6829 && refers_to_regno_for_reload_p (valueno, end_hard_regno (mode, valueno),
6830 goal, (rtx*) 0))
6831 return 0;
6833 /* Reject registers that overlap GOAL. */
6835 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6836 nregs = hard_regno_nregs (regno, mode);
6837 else
6838 nregs = 1;
6839 valuenregs = hard_regno_nregs (valueno, mode);
6841 if (!goal_mem && !goal_const
6842 && regno + nregs > valueno && regno < valueno + valuenregs)
6843 return 0;
6845 /* Reject VALUE if it is one of the regs reserved for reloads.
6846 Reload1 knows how to reuse them anyway, and it would get
6847 confused if we allocated one without its knowledge.
6848 (Now that insns introduced by reload are ignored above,
6849 this case shouldn't happen, but I'm not positive.) */
6851 if (reload_reg_p != 0 && reload_reg_p != (short *) HOST_WIDE_INT_1)
6853 int i;
6854 for (i = 0; i < valuenregs; ++i)
6855 if (reload_reg_p[valueno + i] >= 0)
6856 return 0;
6859 /* Reject VALUE if it is a register being used for an input reload
6860 even if it is not one of those reserved. */
6862 if (reload_reg_p != 0)
6864 int i;
6865 for (i = 0; i < n_reloads; i++)
6866 if (rld[i].reg_rtx != 0
6867 && rld[i].in
6868 && (int) REGNO (rld[i].reg_rtx) < valueno + valuenregs
6869 && (int) END_REGNO (rld[i].reg_rtx) > valueno)
6870 return 0;
6873 if (goal_mem)
6874 /* We must treat frame pointer as varying here,
6875 since it can vary--in a nonlocal goto as generated by expand_goto. */
6876 goal_mem_addr_varies = !CONSTANT_ADDRESS_P (XEXP (goal, 0));
6878 /* Now verify that the values of GOAL and VALUE remain unaltered
6879 until INSN is reached. */
6881 p = insn;
6882 while (1)
6884 p = PREV_INSN (p);
6885 if (p == where)
6886 return value;
6888 /* Don't trust the conversion past a function call
6889 if either of the two is in a call-clobbered register, or memory. */
6890 if (CALL_P (p))
6892 int i;
6894 if (goal_mem || need_stable_sp)
6895 return 0;
6897 if (regno >= 0 && regno < FIRST_PSEUDO_REGISTER)
6898 for (i = 0; i < nregs; ++i)
6899 if (call_used_regs[regno + i]
6900 || targetm.hard_regno_call_part_clobbered (regno + i, mode))
6901 return 0;
6903 if (valueno >= 0 && valueno < FIRST_PSEUDO_REGISTER)
6904 for (i = 0; i < valuenregs; ++i)
6905 if (call_used_regs[valueno + i]
6906 || targetm.hard_regno_call_part_clobbered (valueno + i,
6907 mode))
6908 return 0;
6911 if (INSN_P (p))
6913 pat = PATTERN (p);
6915 /* Watch out for unspec_volatile, and volatile asms. */
6916 if (volatile_insn_p (pat))
6917 return 0;
6919 /* If this insn P stores in either GOAL or VALUE, return 0.
6920 If GOAL is a memory ref and this insn writes memory, return 0.
6921 If GOAL is a memory ref and its address is not constant,
6922 and this insn P changes a register used in GOAL, return 0. */
6924 if (GET_CODE (pat) == COND_EXEC)
6925 pat = COND_EXEC_CODE (pat);
6926 if (GET_CODE (pat) == SET || GET_CODE (pat) == CLOBBER)
6928 rtx dest = SET_DEST (pat);
6929 while (GET_CODE (dest) == SUBREG
6930 || GET_CODE (dest) == ZERO_EXTRACT
6931 || GET_CODE (dest) == STRICT_LOW_PART)
6932 dest = XEXP (dest, 0);
6933 if (REG_P (dest))
6935 int xregno = REGNO (dest);
6936 int end_xregno = END_REGNO (dest);
6937 if (xregno < regno + nregs && end_xregno > regno)
6938 return 0;
6939 if (xregno < valueno + valuenregs
6940 && end_xregno > valueno)
6941 return 0;
6942 if (goal_mem_addr_varies
6943 && reg_overlap_mentioned_for_reload_p (dest, goal))
6944 return 0;
6945 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6946 return 0;
6948 else if (goal_mem && MEM_P (dest)
6949 && ! push_operand (dest, GET_MODE (dest)))
6950 return 0;
6951 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6952 && reg_equiv_memory_loc (regno) != 0)
6953 return 0;
6954 else if (need_stable_sp && push_operand (dest, GET_MODE (dest)))
6955 return 0;
6957 else if (GET_CODE (pat) == PARALLEL)
6959 int i;
6960 for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
6962 rtx v1 = XVECEXP (pat, 0, i);
6963 if (GET_CODE (v1) == COND_EXEC)
6964 v1 = COND_EXEC_CODE (v1);
6965 if (GET_CODE (v1) == SET || GET_CODE (v1) == CLOBBER)
6967 rtx dest = SET_DEST (v1);
6968 while (GET_CODE (dest) == SUBREG
6969 || GET_CODE (dest) == ZERO_EXTRACT
6970 || GET_CODE (dest) == STRICT_LOW_PART)
6971 dest = XEXP (dest, 0);
6972 if (REG_P (dest))
6974 int xregno = REGNO (dest);
6975 int end_xregno = END_REGNO (dest);
6976 if (xregno < regno + nregs
6977 && end_xregno > regno)
6978 return 0;
6979 if (xregno < valueno + valuenregs
6980 && end_xregno > valueno)
6981 return 0;
6982 if (goal_mem_addr_varies
6983 && reg_overlap_mentioned_for_reload_p (dest,
6984 goal))
6985 return 0;
6986 if (xregno == STACK_POINTER_REGNUM && need_stable_sp)
6987 return 0;
6989 else if (goal_mem && MEM_P (dest)
6990 && ! push_operand (dest, GET_MODE (dest)))
6991 return 0;
6992 else if (MEM_P (dest) && regno >= FIRST_PSEUDO_REGISTER
6993 && reg_equiv_memory_loc (regno) != 0)
6994 return 0;
6995 else if (need_stable_sp
6996 && push_operand (dest, GET_MODE (dest)))
6997 return 0;
7002 if (CALL_P (p) && CALL_INSN_FUNCTION_USAGE (p))
7004 rtx link;
7006 for (link = CALL_INSN_FUNCTION_USAGE (p); XEXP (link, 1) != 0;
7007 link = XEXP (link, 1))
7009 pat = XEXP (link, 0);
7010 if (GET_CODE (pat) == CLOBBER)
7012 rtx dest = SET_DEST (pat);
7014 if (REG_P (dest))
7016 int xregno = REGNO (dest);
7017 int end_xregno = END_REGNO (dest);
7019 if (xregno < regno + nregs
7020 && end_xregno > regno)
7021 return 0;
7022 else if (xregno < valueno + valuenregs
7023 && end_xregno > valueno)
7024 return 0;
7025 else if (goal_mem_addr_varies
7026 && reg_overlap_mentioned_for_reload_p (dest,
7027 goal))
7028 return 0;
7031 else if (goal_mem && MEM_P (dest)
7032 && ! push_operand (dest, GET_MODE (dest)))
7033 return 0;
7034 else if (need_stable_sp
7035 && push_operand (dest, GET_MODE (dest)))
7036 return 0;
7041 #if AUTO_INC_DEC
7042 /* If this insn auto-increments or auto-decrements
7043 either regno or valueno, return 0 now.
7044 If GOAL is a memory ref and its address is not constant,
7045 and this insn P increments a register used in GOAL, return 0. */
7047 rtx link;
7049 for (link = REG_NOTES (p); link; link = XEXP (link, 1))
7050 if (REG_NOTE_KIND (link) == REG_INC
7051 && REG_P (XEXP (link, 0)))
7053 int incno = REGNO (XEXP (link, 0));
7054 if (incno < regno + nregs && incno >= regno)
7055 return 0;
7056 if (incno < valueno + valuenregs && incno >= valueno)
7057 return 0;
7058 if (goal_mem_addr_varies
7059 && reg_overlap_mentioned_for_reload_p (XEXP (link, 0),
7060 goal))
7061 return 0;
7064 #endif
7069 /* Find a place where INCED appears in an increment or decrement operator
7070 within X, and return the amount INCED is incremented or decremented by.
7071 The value is always positive. */
7073 static poly_int64
7074 find_inc_amount (rtx x, rtx inced)
7076 enum rtx_code code = GET_CODE (x);
7077 const char *fmt;
7078 int i;
7080 if (code == MEM)
7082 rtx addr = XEXP (x, 0);
7083 if ((GET_CODE (addr) == PRE_DEC
7084 || GET_CODE (addr) == POST_DEC
7085 || GET_CODE (addr) == PRE_INC
7086 || GET_CODE (addr) == POST_INC)
7087 && XEXP (addr, 0) == inced)
7088 return GET_MODE_SIZE (GET_MODE (x));
7089 else if ((GET_CODE (addr) == PRE_MODIFY
7090 || GET_CODE (addr) == POST_MODIFY)
7091 && GET_CODE (XEXP (addr, 1)) == PLUS
7092 && XEXP (addr, 0) == XEXP (XEXP (addr, 1), 0)
7093 && XEXP (addr, 0) == inced
7094 && CONST_INT_P (XEXP (XEXP (addr, 1), 1)))
7096 i = INTVAL (XEXP (XEXP (addr, 1), 1));
7097 return i < 0 ? -i : i;
7101 fmt = GET_RTX_FORMAT (code);
7102 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
7104 if (fmt[i] == 'e')
7106 poly_int64 tem = find_inc_amount (XEXP (x, i), inced);
7107 if (maybe_ne (tem, 0))
7108 return tem;
7110 if (fmt[i] == 'E')
7112 int j;
7113 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
7115 poly_int64 tem = find_inc_amount (XVECEXP (x, i, j), inced);
7116 if (maybe_ne (tem, 0))
7117 return tem;
7122 return 0;
7125 /* Return 1 if registers from REGNO to ENDREGNO are the subjects of a
7126 REG_INC note in insn INSN. REGNO must refer to a hard register. */
7128 static int
7129 reg_inc_found_and_valid_p (unsigned int regno, unsigned int endregno,
7130 rtx insn)
7132 rtx link;
7134 if (!AUTO_INC_DEC)
7135 return 0;
7137 gcc_assert (insn);
7139 if (! INSN_P (insn))
7140 return 0;
7142 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
7143 if (REG_NOTE_KIND (link) == REG_INC)
7145 unsigned int test = (int) REGNO (XEXP (link, 0));
7146 if (test >= regno && test < endregno)
7147 return 1;
7149 return 0;
7152 /* Return 1 if register REGNO is the subject of a clobber in insn INSN.
7153 If SETS is 1, also consider SETs. If SETS is 2, enable checking
7154 REG_INC. REGNO must refer to a hard register. */
7157 regno_clobbered_p (unsigned int regno, rtx_insn *insn, machine_mode mode,
7158 int sets)
7160 /* regno must be a hard register. */
7161 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
7163 unsigned int endregno = end_hard_regno (mode, regno);
7165 if ((GET_CODE (PATTERN (insn)) == CLOBBER
7166 || (sets == 1 && GET_CODE (PATTERN (insn)) == SET))
7167 && REG_P (XEXP (PATTERN (insn), 0)))
7169 unsigned int test = REGNO (XEXP (PATTERN (insn), 0));
7171 return test >= regno && test < endregno;
7174 if (sets == 2 && reg_inc_found_and_valid_p (regno, endregno, insn))
7175 return 1;
7177 if (GET_CODE (PATTERN (insn)) == PARALLEL)
7179 int i = XVECLEN (PATTERN (insn), 0) - 1;
7181 for (; i >= 0; i--)
7183 rtx elt = XVECEXP (PATTERN (insn), 0, i);
7184 if ((GET_CODE (elt) == CLOBBER
7185 || (sets == 1 && GET_CODE (elt) == SET))
7186 && REG_P (XEXP (elt, 0)))
7188 unsigned int test = REGNO (XEXP (elt, 0));
7190 if (test >= regno && test < endregno)
7191 return 1;
7193 if (sets == 2
7194 && reg_inc_found_and_valid_p (regno, endregno, elt))
7195 return 1;
7199 return 0;
7202 /* Find the low part, with mode MODE, of a hard regno RELOADREG. */
7204 reload_adjust_reg_for_mode (rtx reloadreg, machine_mode mode)
7206 int regno;
7208 if (GET_MODE (reloadreg) == mode)
7209 return reloadreg;
7211 regno = REGNO (reloadreg);
7213 if (REG_WORDS_BIG_ENDIAN)
7214 regno += ((int) REG_NREGS (reloadreg)
7215 - (int) hard_regno_nregs (regno, mode));
7217 return gen_rtx_REG (mode, regno);
7220 static const char *const reload_when_needed_name[] =
7222 "RELOAD_FOR_INPUT",
7223 "RELOAD_FOR_OUTPUT",
7224 "RELOAD_FOR_INSN",
7225 "RELOAD_FOR_INPUT_ADDRESS",
7226 "RELOAD_FOR_INPADDR_ADDRESS",
7227 "RELOAD_FOR_OUTPUT_ADDRESS",
7228 "RELOAD_FOR_OUTADDR_ADDRESS",
7229 "RELOAD_FOR_OPERAND_ADDRESS",
7230 "RELOAD_FOR_OPADDR_ADDR",
7231 "RELOAD_OTHER",
7232 "RELOAD_FOR_OTHER_ADDRESS"
7235 /* These functions are used to print the variables set by 'find_reloads' */
7237 DEBUG_FUNCTION void
7238 debug_reload_to_stream (FILE *f)
7240 int r;
7241 const char *prefix;
7243 if (! f)
7244 f = stderr;
7245 for (r = 0; r < n_reloads; r++)
7247 fprintf (f, "Reload %d: ", r);
7249 if (rld[r].in != 0)
7251 fprintf (f, "reload_in (%s) = ",
7252 GET_MODE_NAME (rld[r].inmode));
7253 print_inline_rtx (f, rld[r].in, 24);
7254 fprintf (f, "\n\t");
7257 if (rld[r].out != 0)
7259 fprintf (f, "reload_out (%s) = ",
7260 GET_MODE_NAME (rld[r].outmode));
7261 print_inline_rtx (f, rld[r].out, 24);
7262 fprintf (f, "\n\t");
7265 fprintf (f, "%s, ", reg_class_names[(int) rld[r].rclass]);
7267 fprintf (f, "%s (opnum = %d)",
7268 reload_when_needed_name[(int) rld[r].when_needed],
7269 rld[r].opnum);
7271 if (rld[r].optional)
7272 fprintf (f, ", optional");
7274 if (rld[r].nongroup)
7275 fprintf (f, ", nongroup");
7277 if (maybe_ne (rld[r].inc, 0))
7279 fprintf (f, ", inc by ");
7280 print_dec (rld[r].inc, f, SIGNED);
7283 if (rld[r].nocombine)
7284 fprintf (f, ", can't combine");
7286 if (rld[r].secondary_p)
7287 fprintf (f, ", secondary_reload_p");
7289 if (rld[r].in_reg != 0)
7291 fprintf (f, "\n\treload_in_reg: ");
7292 print_inline_rtx (f, rld[r].in_reg, 24);
7295 if (rld[r].out_reg != 0)
7297 fprintf (f, "\n\treload_out_reg: ");
7298 print_inline_rtx (f, rld[r].out_reg, 24);
7301 if (rld[r].reg_rtx != 0)
7303 fprintf (f, "\n\treload_reg_rtx: ");
7304 print_inline_rtx (f, rld[r].reg_rtx, 24);
7307 prefix = "\n\t";
7308 if (rld[r].secondary_in_reload != -1)
7310 fprintf (f, "%ssecondary_in_reload = %d",
7311 prefix, rld[r].secondary_in_reload);
7312 prefix = ", ";
7315 if (rld[r].secondary_out_reload != -1)
7316 fprintf (f, "%ssecondary_out_reload = %d\n",
7317 prefix, rld[r].secondary_out_reload);
7319 prefix = "\n\t";
7320 if (rld[r].secondary_in_icode != CODE_FOR_nothing)
7322 fprintf (f, "%ssecondary_in_icode = %s", prefix,
7323 insn_data[rld[r].secondary_in_icode].name);
7324 prefix = ", ";
7327 if (rld[r].secondary_out_icode != CODE_FOR_nothing)
7328 fprintf (f, "%ssecondary_out_icode = %s", prefix,
7329 insn_data[rld[r].secondary_out_icode].name);
7331 fprintf (f, "\n");
7335 DEBUG_FUNCTION void
7336 debug_reload (void)
7338 debug_reload_to_stream (stderr);