1 /* Compute different info about registers.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996
3 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
4 2009 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
23 /* This file contains regscan pass of the compiler and passes for
24 dealing with info about modes of pseudo-registers inside
25 subregisters. It also defines some tables of information about the
26 hardware registers, function init_reg_sets to initialize the
27 tables, and other auxiliary functions to deal with info about
28 registers and their classes. */
32 #include "coretypes.h"
34 #include "hard-reg-set.h"
39 #include "basic-block.h"
41 #include "addresses.h"
43 #include "insn-config.h"
47 #include "diagnostic-core.h"
53 #include "tree-pass.h"
57 /* Maximum register number used in this function, plus one. */
62 struct target_regs default_target_regs;
64 struct target_regs *this_target_regs = &default_target_regs;
67 /* Register tables used by many passes. */
69 /* Indexed by hard register number, contains 1 for registers
70 that are fixed use (stack pointer, pc, frame pointer, etc.).
71 These are the registers that cannot be used to allocate
72 a pseudo reg for general use. */
73 char fixed_regs[FIRST_PSEUDO_REGISTER];
75 /* Same info as a HARD_REG_SET. */
76 HARD_REG_SET fixed_reg_set;
78 /* Data for initializing the above. */
79 static const char initial_fixed_regs[] = FIXED_REGISTERS;
81 /* Indexed by hard register number, contains 1 for registers
82 that are fixed use or are clobbered by function calls.
83 These are the registers that cannot be used to allocate
84 a pseudo reg whose life crosses calls unless we are able
85 to save/restore them across the calls. */
86 char call_used_regs[FIRST_PSEUDO_REGISTER];
88 /* Same info as a HARD_REG_SET. */
89 HARD_REG_SET call_used_reg_set;
91 /* Data for initializing the above. */
92 static const char initial_call_used_regs[] = CALL_USED_REGISTERS;
94 /* This is much like call_used_regs, except it doesn't have to
95 be a superset of FIXED_REGISTERS. This vector indicates
96 what is really call clobbered, and is used when defining
97 regs_invalidated_by_call. */
98 #ifdef CALL_REALLY_USED_REGISTERS
99 char call_really_used_regs[] = CALL_REALLY_USED_REGISTERS;
102 #ifdef CALL_REALLY_USED_REGISTERS
103 #define CALL_REALLY_USED_REGNO_P(X) call_really_used_regs[X]
105 #define CALL_REALLY_USED_REGNO_P(X) call_used_regs[X]
109 /* Contains registers that are fixed use -- i.e. in fixed_reg_set -- or
110 a function value return register or TARGET_STRUCT_VALUE_RTX or
111 STATIC_CHAIN_REGNUM. These are the registers that cannot hold quantities
112 across calls even if we are willing to save and restore them. */
114 HARD_REG_SET call_fixed_reg_set;
116 /* Indexed by hard register number, contains 1 for registers
117 that are being used for global register decls.
118 These must be exempt from ordinary flow analysis
119 and are also considered fixed. */
120 char global_regs[FIRST_PSEUDO_REGISTER];
122 /* Contains 1 for registers that are set or clobbered by calls. */
123 /* ??? Ideally, this would be just call_used_regs plus global_regs, but
124 for someone's bright idea to have call_used_regs strictly include
125 fixed_regs. Which leaves us guessing as to the set of fixed_regs
126 that are actually preserved. We know for sure that those associated
127 with the local stack frame are safe, but scant others. */
128 HARD_REG_SET regs_invalidated_by_call;
130 /* Same information as REGS_INVALIDATED_BY_CALL but in regset form to be used
131 in dataflow more conveniently. */
132 regset regs_invalidated_by_call_regset;
134 /* The bitmap_obstack is used to hold some static variables that
135 should not be reset after each function is compiled. */
136 static bitmap_obstack persistent_obstack;
138 /* Table of register numbers in the order in which to try to use them. */
139 #ifdef REG_ALLOC_ORDER
140 int reg_alloc_order[FIRST_PSEUDO_REGISTER] = REG_ALLOC_ORDER;
142 /* The inverse of reg_alloc_order. */
143 int inv_reg_alloc_order[FIRST_PSEUDO_REGISTER];
146 /* For each reg class, a HARD_REG_SET saying which registers are in it. */
147 HARD_REG_SET reg_class_contents[N_REG_CLASSES];
149 /* For each reg class, a boolean saying whether the class contains only
151 bool class_only_fixed_regs[N_REG_CLASSES];
153 /* The same information, but as an array of unsigned ints. We copy from
154 these unsigned ints to the table above. We do this so the tm.h files
155 do not have to be aware of the wordsize for machines with <= 64 regs.
156 Note that we hard-code 32 here, not HOST_BITS_PER_INT. */
158 ((FIRST_PSEUDO_REGISTER + (32 - 1)) / 32)
160 static const unsigned int_reg_class_contents[N_REG_CLASSES][N_REG_INTS]
161 = REG_CLASS_CONTENTS;
163 /* For each reg class, number of regs it contains. */
164 unsigned int reg_class_size[N_REG_CLASSES];
166 /* For each reg class, table listing all the classes contained in it. */
167 enum reg_class reg_class_subclasses[N_REG_CLASSES][N_REG_CLASSES];
169 /* For each pair of reg classes,
170 a largest reg class contained in their union. */
171 enum reg_class reg_class_subunion[N_REG_CLASSES][N_REG_CLASSES];
173 /* For each pair of reg classes,
174 the smallest reg class containing their union. */
175 enum reg_class reg_class_superunion[N_REG_CLASSES][N_REG_CLASSES];
177 /* Array containing all of the register names. */
178 const char * reg_names[] = REGISTER_NAMES;
180 /* Array containing all of the register class names. */
181 const char * reg_class_names[] = REG_CLASS_NAMES;
183 /* 1 if there is a register of given mode. */
184 bool have_regs_of_mode [MAX_MACHINE_MODE];
186 /* 1 if class does contain register of given mode. */
187 char contains_reg_of_mode [N_REG_CLASSES] [MAX_MACHINE_MODE];
189 /* Maximum cost of moving from a register in one class to a register in
190 another class. Based on TARGET_REGISTER_MOVE_COST. */
191 move_table *move_cost[MAX_MACHINE_MODE];
193 /* Similar, but here we don't have to move if the first index is a subset
194 of the second so in that case the cost is zero. */
195 move_table *may_move_in_cost[MAX_MACHINE_MODE];
197 /* Similar, but here we don't have to move if the first index is a superset
198 of the second so in that case the cost is zero. */
199 move_table *may_move_out_cost[MAX_MACHINE_MODE];
201 /* Keep track of the last mode we initialized move costs for. */
202 static int last_mode_for_init_move_cost;
204 /* Sample MEM values for use by memory_move_secondary_cost. */
205 static GTY(()) rtx top_of_stack[MAX_MACHINE_MODE];
207 /* No more global register variables may be declared; true once
208 reginfo has been initialized. */
209 static int no_global_reg_vars = 0;
211 /* Given a register bitmap, turn on the bits in a HARD_REG_SET that
212 correspond to the hard registers, if any, set in that map. This
213 could be done far more efficiently by having all sorts of special-cases
214 with moving single words, but probably isn't worth the trouble. */
216 reg_set_to_hard_reg_set (HARD_REG_SET *to, const_bitmap from)
221 EXECUTE_IF_SET_IN_BITMAP (from, 0, i, bi)
223 if (i >= FIRST_PSEUDO_REGISTER)
225 SET_HARD_REG_BIT (*to, i);
229 /* Function called only once to initialize the above data on reg usage.
230 Once this is done, various switches may override. */
236 /* First copy the register information from the initial int form into
239 for (i = 0; i < N_REG_CLASSES; i++)
241 CLEAR_HARD_REG_SET (reg_class_contents[i]);
243 /* Note that we hard-code 32 here, not HOST_BITS_PER_INT. */
244 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
245 if (int_reg_class_contents[i][j / 32]
246 & ((unsigned) 1 << (j % 32)))
247 SET_HARD_REG_BIT (reg_class_contents[i], j);
250 /* Sanity check: make sure the target macros FIXED_REGISTERS and
251 CALL_USED_REGISTERS had the right number of initializers. */
252 gcc_assert (sizeof fixed_regs == sizeof initial_fixed_regs);
253 gcc_assert (sizeof call_used_regs == sizeof initial_call_used_regs);
255 memcpy (fixed_regs, initial_fixed_regs, sizeof fixed_regs);
256 memcpy (call_used_regs, initial_call_used_regs, sizeof call_used_regs);
257 memset (global_regs, 0, sizeof global_regs);
260 /* Initialize may_move_cost and friends for mode M. */
262 init_move_cost (enum machine_mode m)
264 static unsigned short last_move_cost[N_REG_CLASSES][N_REG_CLASSES];
265 bool all_match = true;
268 gcc_assert (have_regs_of_mode[m]);
269 for (i = 0; i < N_REG_CLASSES; i++)
270 if (contains_reg_of_mode[i][m])
271 for (j = 0; j < N_REG_CLASSES; j++)
274 if (!contains_reg_of_mode[j][m])
278 cost = register_move_cost (m, (enum reg_class) i,
280 gcc_assert (cost < 65535);
282 all_match &= (last_move_cost[i][j] == cost);
283 last_move_cost[i][j] = cost;
285 if (all_match && last_mode_for_init_move_cost != -1)
287 move_cost[m] = move_cost[last_mode_for_init_move_cost];
288 may_move_in_cost[m] = may_move_in_cost[last_mode_for_init_move_cost];
289 may_move_out_cost[m] = may_move_out_cost[last_mode_for_init_move_cost];
292 last_mode_for_init_move_cost = m;
293 move_cost[m] = (move_table *)xmalloc (sizeof (move_table)
295 may_move_in_cost[m] = (move_table *)xmalloc (sizeof (move_table)
297 may_move_out_cost[m] = (move_table *)xmalloc (sizeof (move_table)
299 for (i = 0; i < N_REG_CLASSES; i++)
300 if (contains_reg_of_mode[i][m])
301 for (j = 0; j < N_REG_CLASSES; j++)
304 enum reg_class *p1, *p2;
306 if (last_move_cost[i][j] == 65535)
308 move_cost[m][i][j] = 65535;
309 may_move_in_cost[m][i][j] = 65535;
310 may_move_out_cost[m][i][j] = 65535;
314 cost = last_move_cost[i][j];
316 for (p2 = ®_class_subclasses[j][0];
317 *p2 != LIM_REG_CLASSES; p2++)
318 if (*p2 != i && contains_reg_of_mode[*p2][m])
319 cost = MAX (cost, move_cost[m][i][*p2]);
321 for (p1 = ®_class_subclasses[i][0];
322 *p1 != LIM_REG_CLASSES; p1++)
323 if (*p1 != j && contains_reg_of_mode[*p1][m])
324 cost = MAX (cost, move_cost[m][*p1][j]);
326 gcc_assert (cost <= 65535);
327 move_cost[m][i][j] = cost;
329 if (reg_class_subset_p ((enum reg_class) i, (enum reg_class) j))
330 may_move_in_cost[m][i][j] = 0;
332 may_move_in_cost[m][i][j] = cost;
334 if (reg_class_subset_p ((enum reg_class) j, (enum reg_class) i))
335 may_move_out_cost[m][i][j] = 0;
337 may_move_out_cost[m][i][j] = cost;
341 for (j = 0; j < N_REG_CLASSES; j++)
343 move_cost[m][i][j] = 65535;
344 may_move_in_cost[m][i][j] = 65535;
345 may_move_out_cost[m][i][j] = 65535;
349 /* We need to save copies of some of the register information which
350 can be munged by command-line switches so we can restore it during
351 subsequent back-end reinitialization. */
352 static char saved_fixed_regs[FIRST_PSEUDO_REGISTER];
353 static char saved_call_used_regs[FIRST_PSEUDO_REGISTER];
354 #ifdef CALL_REALLY_USED_REGISTERS
355 static char saved_call_really_used_regs[FIRST_PSEUDO_REGISTER];
357 static const char *saved_reg_names[FIRST_PSEUDO_REGISTER];
359 /* Save the register information. */
361 save_register_info (void)
363 /* Sanity check: make sure the target macros FIXED_REGISTERS and
364 CALL_USED_REGISTERS had the right number of initializers. */
365 gcc_assert (sizeof fixed_regs == sizeof saved_fixed_regs);
366 gcc_assert (sizeof call_used_regs == sizeof saved_call_used_regs);
367 memcpy (saved_fixed_regs, fixed_regs, sizeof fixed_regs);
368 memcpy (saved_call_used_regs, call_used_regs, sizeof call_used_regs);
370 /* Likewise for call_really_used_regs. */
371 #ifdef CALL_REALLY_USED_REGISTERS
372 gcc_assert (sizeof call_really_used_regs
373 == sizeof saved_call_really_used_regs);
374 memcpy (saved_call_really_used_regs, call_really_used_regs,
375 sizeof call_really_used_regs);
378 /* And similarly for reg_names. */
379 gcc_assert (sizeof reg_names == sizeof saved_reg_names);
380 memcpy (saved_reg_names, reg_names, sizeof reg_names);
383 /* Restore the register information. */
385 restore_register_info (void)
387 memcpy (fixed_regs, saved_fixed_regs, sizeof fixed_regs);
388 memcpy (call_used_regs, saved_call_used_regs, sizeof call_used_regs);
390 #ifdef CALL_REALLY_USED_REGISTERS
391 memcpy (call_really_used_regs, saved_call_really_used_regs,
392 sizeof call_really_used_regs);
395 memcpy (reg_names, saved_reg_names, sizeof reg_names);
398 /* After switches have been processed, which perhaps alter
399 `fixed_regs' and `call_used_regs', convert them to HARD_REG_SETs. */
401 init_reg_sets_1 (void)
404 unsigned int /* enum machine_mode */ m;
406 restore_register_info ();
408 #ifdef REG_ALLOC_ORDER
409 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
410 inv_reg_alloc_order[reg_alloc_order[i]] = i;
413 /* This macro allows the fixed or call-used registers
414 and the register classes to depend on target flags. */
416 #ifdef CONDITIONAL_REGISTER_USAGE
417 CONDITIONAL_REGISTER_USAGE;
420 /* Compute number of hard regs in each class. */
422 memset (reg_class_size, 0, sizeof reg_class_size);
423 for (i = 0; i < N_REG_CLASSES; i++)
425 bool any_nonfixed = false;
426 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
427 if (TEST_HARD_REG_BIT (reg_class_contents[i], j))
433 class_only_fixed_regs[i] = !any_nonfixed;
436 /* Initialize the table of subunions.
437 reg_class_subunion[I][J] gets the largest-numbered reg-class
438 that is contained in the union of classes I and J. */
440 memset (reg_class_subunion, 0, sizeof reg_class_subunion);
441 for (i = 0; i < N_REG_CLASSES; i++)
443 for (j = 0; j < N_REG_CLASSES; j++)
448 COPY_HARD_REG_SET (c, reg_class_contents[i]);
449 IOR_HARD_REG_SET (c, reg_class_contents[j]);
450 for (k = 0; k < N_REG_CLASSES; k++)
451 if (hard_reg_set_subset_p (reg_class_contents[k], c)
452 && !hard_reg_set_subset_p (reg_class_contents[k],
454 [(int) reg_class_subunion[i][j]]))
455 reg_class_subunion[i][j] = (enum reg_class) k;
459 /* Initialize the table of superunions.
460 reg_class_superunion[I][J] gets the smallest-numbered reg-class
461 containing the union of classes I and J. */
463 memset (reg_class_superunion, 0, sizeof reg_class_superunion);
464 for (i = 0; i < N_REG_CLASSES; i++)
466 for (j = 0; j < N_REG_CLASSES; j++)
471 COPY_HARD_REG_SET (c, reg_class_contents[i]);
472 IOR_HARD_REG_SET (c, reg_class_contents[j]);
473 for (k = 0; k < N_REG_CLASSES; k++)
474 if (hard_reg_set_subset_p (c, reg_class_contents[k]))
477 reg_class_superunion[i][j] = (enum reg_class) k;
481 /* Initialize the tables of subclasses and superclasses of each reg class.
482 First clear the whole table, then add the elements as they are found. */
484 for (i = 0; i < N_REG_CLASSES; i++)
486 for (j = 0; j < N_REG_CLASSES; j++)
487 reg_class_subclasses[i][j] = LIM_REG_CLASSES;
490 for (i = 0; i < N_REG_CLASSES; i++)
492 if (i == (int) NO_REGS)
495 for (j = i + 1; j < N_REG_CLASSES; j++)
496 if (hard_reg_set_subset_p (reg_class_contents[i],
497 reg_class_contents[j]))
499 /* Reg class I is a subclass of J.
500 Add J to the table of superclasses of I. */
503 /* Add I to the table of superclasses of J. */
504 p = ®_class_subclasses[j][0];
505 while (*p != LIM_REG_CLASSES) p++;
506 *p = (enum reg_class) i;
510 /* Initialize "constant" tables. */
512 CLEAR_HARD_REG_SET (fixed_reg_set);
513 CLEAR_HARD_REG_SET (call_used_reg_set);
514 CLEAR_HARD_REG_SET (call_fixed_reg_set);
515 CLEAR_HARD_REG_SET (regs_invalidated_by_call);
516 if (!regs_invalidated_by_call_regset)
518 bitmap_obstack_initialize (&persistent_obstack);
519 regs_invalidated_by_call_regset = ALLOC_REG_SET (&persistent_obstack);
522 CLEAR_REG_SET (regs_invalidated_by_call_regset);
524 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
526 /* call_used_regs must include fixed_regs. */
527 gcc_assert (!fixed_regs[i] || call_used_regs[i]);
528 #ifdef CALL_REALLY_USED_REGISTERS
529 /* call_used_regs must include call_really_used_regs. */
530 gcc_assert (!call_really_used_regs[i] || call_used_regs[i]);
534 SET_HARD_REG_BIT (fixed_reg_set, i);
536 if (call_used_regs[i])
537 SET_HARD_REG_BIT (call_used_reg_set, i);
539 /* There are a couple of fixed registers that we know are safe to
540 exclude from being clobbered by calls:
542 The frame pointer is always preserved across calls. The arg
543 pointer is if it is fixed. The stack pointer usually is,
544 unless TARGET_RETURN_POPS_ARGS, in which case an explicit
545 CLOBBER will be present. If we are generating PIC code, the
546 PIC offset table register is preserved across calls, though the
547 target can override that. */
549 if (i == STACK_POINTER_REGNUM)
551 else if (global_regs[i])
553 SET_HARD_REG_BIT (regs_invalidated_by_call, i);
554 SET_REGNO_REG_SET (regs_invalidated_by_call_regset, i);
556 else if (i == FRAME_POINTER_REGNUM)
558 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
559 else if (i == HARD_FRAME_POINTER_REGNUM)
562 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
563 else if (i == ARG_POINTER_REGNUM && fixed_regs[i])
566 #ifndef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
567 else if (i == (unsigned) PIC_OFFSET_TABLE_REGNUM && fixed_regs[i])
570 else if (CALL_REALLY_USED_REGNO_P (i))
572 SET_HARD_REG_BIT (regs_invalidated_by_call, i);
573 SET_REGNO_REG_SET (regs_invalidated_by_call_regset, i);
577 COPY_HARD_REG_SET(call_fixed_reg_set, fixed_reg_set);
579 /* Preserve global registers if called more than once. */
580 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
584 fixed_regs[i] = call_used_regs[i] = 1;
585 SET_HARD_REG_BIT (fixed_reg_set, i);
586 SET_HARD_REG_BIT (call_used_reg_set, i);
587 SET_HARD_REG_BIT (call_fixed_reg_set, i);
591 memset (have_regs_of_mode, 0, sizeof (have_regs_of_mode));
592 memset (contains_reg_of_mode, 0, sizeof (contains_reg_of_mode));
593 for (m = 0; m < (unsigned int) MAX_MACHINE_MODE; m++)
595 HARD_REG_SET ok_regs;
596 CLEAR_HARD_REG_SET (ok_regs);
597 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
598 if (!fixed_regs [j] && HARD_REGNO_MODE_OK (j, (enum machine_mode) m))
599 SET_HARD_REG_BIT (ok_regs, j);
601 for (i = 0; i < N_REG_CLASSES; i++)
602 if (((unsigned) CLASS_MAX_NREGS ((enum reg_class) i,
603 (enum machine_mode) m)
604 <= reg_class_size[i])
605 && hard_reg_set_intersect_p (ok_regs, reg_class_contents[i]))
607 contains_reg_of_mode [i][m] = 1;
608 have_regs_of_mode [m] = 1;
612 /* Reset move_cost and friends, making sure we only free shared
613 table entries once. */
614 for (i = 0; i < MAX_MACHINE_MODE; i++)
617 for (j = 0; j < i && move_cost[i] != move_cost[j]; j++)
622 free (may_move_in_cost[i]);
623 free (may_move_out_cost[i]);
626 memset (move_cost, 0, sizeof move_cost);
627 memset (may_move_in_cost, 0, sizeof may_move_in_cost);
628 memset (may_move_out_cost, 0, sizeof may_move_out_cost);
629 last_mode_for_init_move_cost = -1;
632 /* Compute the table of register modes.
633 These values are used to record death information for individual registers
634 (as opposed to a multi-register mode).
635 This function might be invoked more than once, if the target has support
636 for changing register usage conventions on a per-function basis.
639 init_reg_modes_target (void)
643 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
644 for (j = 0; j < MAX_MACHINE_MODE; j++)
645 hard_regno_nregs[i][j] = HARD_REGNO_NREGS(i, (enum machine_mode)j);
647 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
649 reg_raw_mode[i] = choose_hard_reg_mode (i, 1, false);
651 /* If we couldn't find a valid mode, just use the previous mode.
652 ??? One situation in which we need to do this is on the mips where
653 HARD_REGNO_NREGS (fpreg, [SD]Fmode) returns 2. Ideally we'd like
654 to use DF mode for the even registers and VOIDmode for the odd
655 (for the cpu models where the odd ones are inaccessible). */
656 if (reg_raw_mode[i] == VOIDmode)
657 reg_raw_mode[i] = i == 0 ? word_mode : reg_raw_mode[i-1];
661 /* Finish initializing the register sets and initialize the register modes.
662 This function might be invoked more than once, if the target has support
663 for changing register usage conventions on a per-function basis.
668 /* This finishes what was started by init_reg_sets, but couldn't be done
669 until after register usage was specified. */
673 /* The same as previous function plus initializing IRA. */
678 /* caller_save needs to be re-initialized. */
679 caller_save_initialized_p = false;
683 /* Initialize some fake stack-frame MEM references for use in
684 memory_move_secondary_cost. */
686 init_fake_stack_mems (void)
690 for (i = 0; i < MAX_MACHINE_MODE; i++)
691 top_of_stack[i] = gen_rtx_MEM ((enum machine_mode) i, stack_pointer_rtx);
695 /* Compute cost of moving data from a register of class FROM to one of
699 register_move_cost (enum machine_mode mode, enum reg_class from,
702 return targetm.register_move_cost (mode, from, to);
705 /* Compute cost of moving registers to/from memory. */
707 memory_move_cost (enum machine_mode mode, enum reg_class rclass, bool in)
709 return targetm.memory_move_cost (mode, rclass, in);
712 /* Compute extra cost of moving registers to/from memory due to reloads.
713 Only needed if secondary reloads are required for memory moves. */
715 memory_move_secondary_cost (enum machine_mode mode, enum reg_class rclass,
718 enum reg_class altclass;
719 int partial_cost = 0;
720 /* We need a memory reference to feed to SECONDARY... macros. */
721 /* mem may be unused even if the SECONDARY_ macros are defined. */
722 rtx mem ATTRIBUTE_UNUSED = top_of_stack[(int) mode];
724 altclass = secondary_reload_class (in ? 1 : 0, rclass, mode, mem);
726 if (altclass == NO_REGS)
730 partial_cost = register_move_cost (mode, altclass, rclass);
732 partial_cost = register_move_cost (mode, rclass, altclass);
734 if (rclass == altclass)
735 /* This isn't simply a copy-to-temporary situation. Can't guess
736 what it is, so TARGET_MEMORY_MOVE_COST really ought not to be
737 calling here in that case.
739 I'm tempted to put in an assert here, but returning this will
740 probably only give poor estimates, which is what we would've
741 had before this code anyways. */
744 /* Check if the secondary reload register will also need a
746 return memory_move_secondary_cost (mode, altclass, in) + partial_cost;
749 /* Return a machine mode that is legitimate for hard reg REGNO and large
750 enough to save nregs. If we can't find one, return VOIDmode.
751 If CALL_SAVED is true, only consider modes that are call saved. */
753 choose_hard_reg_mode (unsigned int regno ATTRIBUTE_UNUSED,
754 unsigned int nregs, bool call_saved)
756 unsigned int /* enum machine_mode */ m;
757 enum machine_mode found_mode = VOIDmode, mode;
759 /* We first look for the largest integer mode that can be validly
760 held in REGNO. If none, we look for the largest floating-point mode.
761 If we still didn't find a valid mode, try CCmode. */
763 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
765 mode = GET_MODE_WIDER_MODE (mode))
766 if ((unsigned) hard_regno_nregs[regno][mode] == nregs
767 && HARD_REGNO_MODE_OK (regno, mode)
768 && (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode)))
771 if (found_mode != VOIDmode)
774 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
776 mode = GET_MODE_WIDER_MODE (mode))
777 if ((unsigned) hard_regno_nregs[regno][mode] == nregs
778 && HARD_REGNO_MODE_OK (regno, mode)
779 && (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode)))
782 if (found_mode != VOIDmode)
785 for (mode = GET_CLASS_NARROWEST_MODE (MODE_VECTOR_FLOAT);
787 mode = GET_MODE_WIDER_MODE (mode))
788 if ((unsigned) hard_regno_nregs[regno][mode] == nregs
789 && HARD_REGNO_MODE_OK (regno, mode)
790 && (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode)))
793 if (found_mode != VOIDmode)
796 for (mode = GET_CLASS_NARROWEST_MODE (MODE_VECTOR_INT);
798 mode = GET_MODE_WIDER_MODE (mode))
799 if ((unsigned) hard_regno_nregs[regno][mode] == nregs
800 && HARD_REGNO_MODE_OK (regno, mode)
801 && (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode)))
804 if (found_mode != VOIDmode)
807 /* Iterate over all of the CCmodes. */
808 for (m = (unsigned int) CCmode; m < (unsigned int) NUM_MACHINE_MODES; ++m)
810 mode = (enum machine_mode) m;
811 if ((unsigned) hard_regno_nregs[regno][mode] == nregs
812 && HARD_REGNO_MODE_OK (regno, mode)
813 && (! call_saved || ! HARD_REGNO_CALL_PART_CLOBBERED (regno, mode)))
817 /* We can't find a mode valid for this register. */
821 /* Specify the usage characteristics of the register named NAME.
822 It should be a fixed register if FIXED and a
823 call-used register if CALL_USED. */
825 fix_register (const char *name, int fixed, int call_used)
829 /* Decode the name and update the primary form of
830 the register info. */
832 if ((i = decode_reg_name (name)) >= 0)
834 if ((i == STACK_POINTER_REGNUM
835 #ifdef HARD_FRAME_POINTER_REGNUM
836 || i == HARD_FRAME_POINTER_REGNUM
838 || i == FRAME_POINTER_REGNUM
841 && (fixed == 0 || call_used == 0))
843 static const char * const what_option[2][2] = {
844 { "call-saved", "call-used" },
845 { "no-such-option", "fixed" }};
847 error ("can't use '%s' as a %s register", name,
848 what_option[fixed][call_used]);
852 fixed_regs[i] = fixed;
853 call_used_regs[i] = call_used;
854 #ifdef CALL_REALLY_USED_REGISTERS
856 call_really_used_regs[i] = call_used;
862 warning (0, "unknown register name: %s", name);
866 /* Mark register number I as global. */
868 globalize_reg (int i)
870 if (fixed_regs[i] == 0 && no_global_reg_vars)
871 error ("global register variable follows a function definition");
875 warning (0, "register used for two global register variables");
879 if (call_used_regs[i] && ! fixed_regs[i])
880 warning (0, "call-clobbered register used for global register variable");
884 /* If we're globalizing the frame pointer, we need to set the
885 appropriate regs_invalidated_by_call bit, even if it's already
886 set in fixed_regs. */
887 if (i != STACK_POINTER_REGNUM)
889 SET_HARD_REG_BIT (regs_invalidated_by_call, i);
890 SET_REGNO_REG_SET (regs_invalidated_by_call_regset, i);
893 /* If already fixed, nothing else to do. */
897 fixed_regs[i] = call_used_regs[i] = 1;
898 #ifdef CALL_REALLY_USED_REGISTERS
899 call_really_used_regs[i] = 1;
902 SET_HARD_REG_BIT (fixed_reg_set, i);
903 SET_HARD_REG_BIT (call_used_reg_set, i);
904 SET_HARD_REG_BIT (call_fixed_reg_set, i);
910 /* Structure used to record preferences of given pseudo. */
913 /* (enum reg_class) prefclass is the preferred class. May be
914 NO_REGS if no class is better than memory. */
917 /* altclass is a register class that we should use for allocating
918 pseudo if no register in the preferred class is available.
919 If no register in this class is available, memory is preferred.
921 It might appear to be more general to have a bitmask of classes here,
922 but since it is recommended that there be a class corresponding to the
923 union of most major pair of classes, that generality is not required. */
926 /* coverclass is a register class that IRA uses for allocating
931 /* Record preferences of each pseudo. This is available after RA is
933 static struct reg_pref *reg_pref;
935 /* Current size of reg_info. */
936 static int reg_info_size;
938 /* Return the reg_class in which pseudo reg number REGNO is best allocated.
939 This function is sometimes called before the info has been computed.
940 When that happens, just return GENERAL_REGS, which is innocuous. */
942 reg_preferred_class (int regno)
947 return (enum reg_class) reg_pref[regno].prefclass;
951 reg_alternate_class (int regno)
956 return (enum reg_class) reg_pref[regno].altclass;
959 /* Return the reg_class which is used by IRA for its allocation. */
961 reg_cover_class (int regno)
966 return (enum reg_class) reg_pref[regno].coverclass;
971 /* Allocate space for reg info. */
973 allocate_reg_info (void)
975 reg_info_size = max_reg_num ();
976 gcc_assert (! reg_pref && ! reg_renumber);
977 reg_renumber = XNEWVEC (short, reg_info_size);
978 reg_pref = XCNEWVEC (struct reg_pref, reg_info_size);
979 memset (reg_renumber, -1, reg_info_size * sizeof (short));
983 /* Resize reg info. The new elements will be uninitialized. Return
984 TRUE if new elements (for new pseudos) were added. */
986 resize_reg_info (void)
990 if (reg_pref == NULL)
992 allocate_reg_info ();
995 if (reg_info_size == max_reg_num ())
998 reg_info_size = max_reg_num ();
999 gcc_assert (reg_pref && reg_renumber);
1000 reg_renumber = XRESIZEVEC (short, reg_renumber, reg_info_size);
1001 reg_pref = XRESIZEVEC (struct reg_pref, reg_pref, reg_info_size);
1002 memset (reg_pref + old, -1,
1003 (reg_info_size - old) * sizeof (struct reg_pref));
1004 memset (reg_renumber + old, -1, (reg_info_size - old) * sizeof (short));
1009 /* Free up the space allocated by allocate_reg_info. */
1011 free_reg_info (void)
1021 free (reg_renumber);
1022 reg_renumber = NULL;
1026 /* Initialize some global data for this pass. */
1031 df_compute_regs_ever_live (true);
1033 /* This prevents dump_flow_info from losing if called
1034 before reginfo is run. */
1036 /* No more global register variables may be declared. */
1037 no_global_reg_vars = 1;
1041 struct rtl_opt_pass pass_reginfo_init =
1045 "reginfo", /* name */
1047 reginfo_init, /* execute */
1050 0, /* static_pass_number */
1051 TV_NONE, /* tv_id */
1052 0, /* properties_required */
1053 0, /* properties_provided */
1054 0, /* properties_destroyed */
1055 0, /* todo_flags_start */
1056 0 /* todo_flags_finish */
1062 /* Set up preferred, alternate, and cover classes for REGNO as
1063 PREFCLASS, ALTCLASS, and COVERCLASS. */
1065 setup_reg_classes (int regno,
1066 enum reg_class prefclass, enum reg_class altclass,
1067 enum reg_class coverclass)
1069 if (reg_pref == NULL)
1071 gcc_assert (reg_info_size == max_reg_num ());
1072 reg_pref[regno].prefclass = prefclass;
1073 reg_pref[regno].altclass = altclass;
1074 reg_pref[regno].coverclass = coverclass;
1078 /* This is the `regscan' pass of the compiler, run just before cse and
1079 again just before loop. It finds the first and last use of each
1082 static void reg_scan_mark_refs (rtx, rtx);
1085 reg_scan (rtx f, unsigned int nregs ATTRIBUTE_UNUSED)
1089 timevar_push (TV_REG_SCAN);
1091 for (insn = f; insn; insn = NEXT_INSN (insn))
1094 reg_scan_mark_refs (PATTERN (insn), insn);
1095 if (REG_NOTES (insn))
1096 reg_scan_mark_refs (REG_NOTES (insn), insn);
1099 timevar_pop (TV_REG_SCAN);
1103 /* X is the expression to scan. INSN is the insn it appears in.
1104 NOTE_FLAG is nonzero if X is from INSN's notes rather than its body.
1105 We should only record information for REGs with numbers
1106 greater than or equal to MIN_REGNO. */
1108 reg_scan_mark_refs (rtx x, rtx insn)
1116 code = GET_CODE (x);
1135 reg_scan_mark_refs (XEXP (x, 0), insn);
1137 reg_scan_mark_refs (XEXP (x, 1), insn);
1142 reg_scan_mark_refs (XEXP (x, 1), insn);
1146 if (MEM_P (XEXP (x, 0)))
1147 reg_scan_mark_refs (XEXP (XEXP (x, 0), 0), insn);
1151 /* Count a set of the destination if it is a register. */
1152 for (dest = SET_DEST (x);
1153 GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
1154 || GET_CODE (dest) == ZERO_EXTEND;
1155 dest = XEXP (dest, 0))
1158 /* If this is setting a pseudo from another pseudo or the sum of a
1159 pseudo and a constant integer and the other pseudo is known to be
1160 a pointer, set the destination to be a pointer as well.
1162 Likewise if it is setting the destination from an address or from a
1163 value equivalent to an address or to the sum of an address and
1166 But don't do any of this if the pseudo corresponds to a user
1167 variable since it should have already been set as a pointer based
1170 if (REG_P (SET_DEST (x))
1171 && REGNO (SET_DEST (x)) >= FIRST_PSEUDO_REGISTER
1172 /* If the destination pseudo is set more than once, then other
1173 sets might not be to a pointer value (consider access to a
1174 union in two threads of control in the presence of global
1175 optimizations). So only set REG_POINTER on the destination
1176 pseudo if this is the only set of that pseudo. */
1177 && DF_REG_DEF_COUNT (REGNO (SET_DEST (x))) == 1
1178 && ! REG_USERVAR_P (SET_DEST (x))
1179 && ! REG_POINTER (SET_DEST (x))
1180 && ((REG_P (SET_SRC (x))
1181 && REG_POINTER (SET_SRC (x)))
1182 || ((GET_CODE (SET_SRC (x)) == PLUS
1183 || GET_CODE (SET_SRC (x)) == LO_SUM)
1184 && CONST_INT_P (XEXP (SET_SRC (x), 1))
1185 && REG_P (XEXP (SET_SRC (x), 0))
1186 && REG_POINTER (XEXP (SET_SRC (x), 0)))
1187 || GET_CODE (SET_SRC (x)) == CONST
1188 || GET_CODE (SET_SRC (x)) == SYMBOL_REF
1189 || GET_CODE (SET_SRC (x)) == LABEL_REF
1190 || (GET_CODE (SET_SRC (x)) == HIGH
1191 && (GET_CODE (XEXP (SET_SRC (x), 0)) == CONST
1192 || GET_CODE (XEXP (SET_SRC (x), 0)) == SYMBOL_REF
1193 || GET_CODE (XEXP (SET_SRC (x), 0)) == LABEL_REF))
1194 || ((GET_CODE (SET_SRC (x)) == PLUS
1195 || GET_CODE (SET_SRC (x)) == LO_SUM)
1196 && (GET_CODE (XEXP (SET_SRC (x), 1)) == CONST
1197 || GET_CODE (XEXP (SET_SRC (x), 1)) == SYMBOL_REF
1198 || GET_CODE (XEXP (SET_SRC (x), 1)) == LABEL_REF))
1199 || ((note = find_reg_note (insn, REG_EQUAL, 0)) != 0
1200 && (GET_CODE (XEXP (note, 0)) == CONST
1201 || GET_CODE (XEXP (note, 0)) == SYMBOL_REF
1202 || GET_CODE (XEXP (note, 0)) == LABEL_REF))))
1203 REG_POINTER (SET_DEST (x)) = 1;
1205 /* If this is setting a register from a register or from a simple
1206 conversion of a register, propagate REG_EXPR. */
1207 if (REG_P (dest) && !REG_ATTRS (dest))
1209 rtx src = SET_SRC (x);
1211 while (GET_CODE (src) == SIGN_EXTEND
1212 || GET_CODE (src) == ZERO_EXTEND
1213 || GET_CODE (src) == TRUNCATE
1214 || (GET_CODE (src) == SUBREG && subreg_lowpart_p (src)))
1215 src = XEXP (src, 0);
1217 set_reg_attrs_from_value (dest, src);
1220 /* ... fall through ... */
1224 const char *fmt = GET_RTX_FORMAT (code);
1226 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1229 reg_scan_mark_refs (XEXP (x, i), insn);
1230 else if (fmt[i] == 'E' && XVEC (x, i) != 0)
1233 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
1234 reg_scan_mark_refs (XVECEXP (x, i, j), insn);
1242 /* Return nonzero if C1 is a subset of C2, i.e., if every register in C1
1245 reg_class_subset_p (enum reg_class c1, enum reg_class c2)
1249 || hard_reg_set_subset_p (reg_class_contents[(int) c1],
1250 reg_class_contents[(int) c2]));
1253 /* Return nonzero if there is a register that is in both C1 and C2. */
1255 reg_classes_intersect_p (reg_class_t c1, reg_class_t c2)
1260 || hard_reg_set_intersect_p (reg_class_contents[(int) c1],
1261 reg_class_contents[(int) c2]));
1266 /* Passes for keeping and updating info about modes of registers
1267 inside subregisters. */
1269 #ifdef CANNOT_CHANGE_MODE_CLASS
1271 struct subregs_of_mode_node
1274 unsigned char modes[MAX_MACHINE_MODE];
1277 static htab_t subregs_of_mode;
1280 som_hash (const void *x)
1282 const struct subregs_of_mode_node *const a =
1283 (const struct subregs_of_mode_node *) x;
1288 som_eq (const void *x, const void *y)
1290 const struct subregs_of_mode_node *const a =
1291 (const struct subregs_of_mode_node *) x;
1292 const struct subregs_of_mode_node *const b =
1293 (const struct subregs_of_mode_node *) y;
1294 return a->block == b->block;
1298 record_subregs_of_mode (rtx subreg)
1300 struct subregs_of_mode_node dummy, *node;
1301 enum machine_mode mode;
1305 if (!REG_P (SUBREG_REG (subreg)))
1308 regno = REGNO (SUBREG_REG (subreg));
1309 mode = GET_MODE (subreg);
1311 if (regno < FIRST_PSEUDO_REGISTER)
1314 dummy.block = regno & -8;
1315 slot = htab_find_slot_with_hash (subregs_of_mode, &dummy,
1316 dummy.block, INSERT);
1317 node = (struct subregs_of_mode_node *) *slot;
1320 node = XCNEW (struct subregs_of_mode_node);
1321 node->block = regno & -8;
1325 node->modes[mode] |= 1 << (regno & 7);
1328 /* Call record_subregs_of_mode for all the subregs in X. */
1330 find_subregs_of_mode (rtx x)
1332 enum rtx_code code = GET_CODE (x);
1333 const char * const fmt = GET_RTX_FORMAT (code);
1337 record_subregs_of_mode (x);
1339 /* Time for some deep diving. */
1340 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1343 find_subregs_of_mode (XEXP (x, i));
1344 else if (fmt[i] == 'E')
1347 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
1348 find_subregs_of_mode (XVECEXP (x, i, j));
1354 init_subregs_of_mode (void)
1359 if (subregs_of_mode)
1360 htab_empty (subregs_of_mode);
1362 subregs_of_mode = htab_create (100, som_hash, som_eq, free);
1365 FOR_BB_INSNS (bb, insn)
1367 find_subregs_of_mode (PATTERN (insn));
1370 /* Return 1 if REGNO has had an invalid mode change in CLASS from FROM
1373 invalid_mode_change_p (unsigned int regno,
1374 enum reg_class rclass ATTRIBUTE_UNUSED,
1375 enum machine_mode from)
1377 struct subregs_of_mode_node dummy, *node;
1381 gcc_assert (subregs_of_mode);
1382 dummy.block = regno & -8;
1383 node = (struct subregs_of_mode_node *)
1384 htab_find_with_hash (subregs_of_mode, &dummy, dummy.block);
1388 mask = 1 << (regno & 7);
1389 for (to = VOIDmode; to < NUM_MACHINE_MODES; to++)
1390 if (node->modes[to] & mask)
1391 if (CANNOT_CHANGE_MODE_CLASS (from, (enum machine_mode) to, rclass))
1398 finish_subregs_of_mode (void)
1400 htab_delete (subregs_of_mode);
1401 subregs_of_mode = 0;
1405 init_subregs_of_mode (void)
1409 finish_subregs_of_mode (void)
1413 #endif /* CANNOT_CHANGE_MODE_CLASS */
1415 #include "gt-reginfo.h"