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, 2010 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"
52 #include "tree-pass.h"
56 /* Maximum register number used in this function, plus one. */
61 struct target_hard_regs default_target_hard_regs
;
62 struct target_regs default_target_regs
;
64 struct target_hard_regs
*this_target_hard_regs
= &default_target_hard_regs
;
65 struct target_regs
*this_target_regs
= &default_target_regs
;
68 /* Data for initializing fixed_regs. */
69 static const char initial_fixed_regs
[] = FIXED_REGISTERS
;
71 /* Data for initializing call_used_regs. */
72 static const char initial_call_used_regs
[] = CALL_USED_REGISTERS
;
74 #ifdef CALL_REALLY_USED_REGISTERS
75 /* Data for initializing call_really_used_regs. */
76 static const char initial_call_really_used_regs
[] = CALL_REALLY_USED_REGISTERS
;
79 #ifdef CALL_REALLY_USED_REGISTERS
80 #define CALL_REALLY_USED_REGNO_P(X) call_really_used_regs[X]
82 #define CALL_REALLY_USED_REGNO_P(X) call_used_regs[X]
85 /* Indexed by hard register number, contains 1 for registers
86 that are being used for global register decls.
87 These must be exempt from ordinary flow analysis
88 and are also considered fixed. */
89 char global_regs
[FIRST_PSEUDO_REGISTER
];
91 /* Same information as REGS_INVALIDATED_BY_CALL but in regset form to be used
92 in dataflow more conveniently. */
93 regset regs_invalidated_by_call_regset
;
95 /* The bitmap_obstack is used to hold some static variables that
96 should not be reset after each function is compiled. */
97 static bitmap_obstack persistent_obstack
;
99 /* Used to initialize reg_alloc_order. */
100 #ifdef REG_ALLOC_ORDER
101 static int initial_reg_alloc_order
[FIRST_PSEUDO_REGISTER
] = REG_ALLOC_ORDER
;
104 /* The same information, but as an array of unsigned ints. We copy from
105 these unsigned ints to the table above. We do this so the tm.h files
106 do not have to be aware of the wordsize for machines with <= 64 regs.
107 Note that we hard-code 32 here, not HOST_BITS_PER_INT. */
109 ((FIRST_PSEUDO_REGISTER + (32 - 1)) / 32)
111 static const unsigned int_reg_class_contents
[N_REG_CLASSES
][N_REG_INTS
]
112 = REG_CLASS_CONTENTS
;
114 /* Array containing all of the register names. */
115 static const char *const initial_reg_names
[] = REGISTER_NAMES
;
117 /* Array containing all of the register class names. */
118 const char * reg_class_names
[] = REG_CLASS_NAMES
;
120 #define last_mode_for_init_move_cost \
121 (this_target_regs->x_last_mode_for_init_move_cost)
123 /* No more global register variables may be declared; true once
124 reginfo has been initialized. */
125 static int no_global_reg_vars
= 0;
127 /* Given a register bitmap, turn on the bits in a HARD_REG_SET that
128 correspond to the hard registers, if any, set in that map. This
129 could be done far more efficiently by having all sorts of special-cases
130 with moving single words, but probably isn't worth the trouble. */
132 reg_set_to_hard_reg_set (HARD_REG_SET
*to
, const_bitmap from
)
137 EXECUTE_IF_SET_IN_BITMAP (from
, 0, i
, bi
)
139 if (i
>= FIRST_PSEUDO_REGISTER
)
141 SET_HARD_REG_BIT (*to
, i
);
145 /* Function called only once per target_globals to initialize the
146 target_hard_regs structure. Once this is done, various switches
153 /* First copy the register information from the initial int form into
156 for (i
= 0; i
< N_REG_CLASSES
; i
++)
158 CLEAR_HARD_REG_SET (reg_class_contents
[i
]);
160 /* Note that we hard-code 32 here, not HOST_BITS_PER_INT. */
161 for (j
= 0; j
< FIRST_PSEUDO_REGISTER
; j
++)
162 if (int_reg_class_contents
[i
][j
/ 32]
163 & ((unsigned) 1 << (j
% 32)))
164 SET_HARD_REG_BIT (reg_class_contents
[i
], j
);
167 /* Sanity check: make sure the target macros FIXED_REGISTERS and
168 CALL_USED_REGISTERS had the right number of initializers. */
169 gcc_assert (sizeof fixed_regs
== sizeof initial_fixed_regs
);
170 gcc_assert (sizeof call_used_regs
== sizeof initial_call_used_regs
);
171 #ifdef CALL_REALLY_USED_REGISTERS
172 gcc_assert (sizeof call_really_used_regs
173 == sizeof initial_call_really_used_regs
);
175 #ifdef REG_ALLOC_ORDER
176 gcc_assert (sizeof reg_alloc_order
== sizeof initial_reg_alloc_order
);
178 gcc_assert (sizeof reg_names
== sizeof initial_reg_names
);
180 memcpy (fixed_regs
, initial_fixed_regs
, sizeof fixed_regs
);
181 memcpy (call_used_regs
, initial_call_used_regs
, sizeof call_used_regs
);
182 #ifdef CALL_REALLY_USED_REGISTERS
183 memcpy (call_really_used_regs
, initial_call_really_used_regs
,
184 sizeof call_really_used_regs
);
186 #ifdef REG_ALLOC_ORDER
187 memcpy (reg_alloc_order
, initial_reg_alloc_order
, sizeof reg_alloc_order
);
189 memcpy (reg_names
, initial_reg_names
, sizeof reg_names
);
192 /* Initialize may_move_cost and friends for mode M. */
194 init_move_cost (enum machine_mode m
)
196 static unsigned short last_move_cost
[N_REG_CLASSES
][N_REG_CLASSES
];
197 bool all_match
= true;
200 gcc_assert (have_regs_of_mode
[m
]);
201 for (i
= 0; i
< N_REG_CLASSES
; i
++)
202 if (contains_reg_of_mode
[i
][m
])
203 for (j
= 0; j
< N_REG_CLASSES
; j
++)
206 if (!contains_reg_of_mode
[j
][m
])
210 cost
= register_move_cost (m
, (enum reg_class
) i
,
212 gcc_assert (cost
< 65535);
214 all_match
&= (last_move_cost
[i
][j
] == cost
);
215 last_move_cost
[i
][j
] = cost
;
217 if (all_match
&& last_mode_for_init_move_cost
!= -1)
219 move_cost
[m
] = move_cost
[last_mode_for_init_move_cost
];
220 may_move_in_cost
[m
] = may_move_in_cost
[last_mode_for_init_move_cost
];
221 may_move_out_cost
[m
] = may_move_out_cost
[last_mode_for_init_move_cost
];
224 last_mode_for_init_move_cost
= m
;
225 move_cost
[m
] = (move_table
*)xmalloc (sizeof (move_table
)
227 may_move_in_cost
[m
] = (move_table
*)xmalloc (sizeof (move_table
)
229 may_move_out_cost
[m
] = (move_table
*)xmalloc (sizeof (move_table
)
231 for (i
= 0; i
< N_REG_CLASSES
; i
++)
232 if (contains_reg_of_mode
[i
][m
])
233 for (j
= 0; j
< N_REG_CLASSES
; j
++)
236 enum reg_class
*p1
, *p2
;
238 if (last_move_cost
[i
][j
] == 65535)
240 move_cost
[m
][i
][j
] = 65535;
241 may_move_in_cost
[m
][i
][j
] = 65535;
242 may_move_out_cost
[m
][i
][j
] = 65535;
246 cost
= last_move_cost
[i
][j
];
248 for (p2
= ®_class_subclasses
[j
][0];
249 *p2
!= LIM_REG_CLASSES
; p2
++)
250 if (*p2
!= i
&& contains_reg_of_mode
[*p2
][m
])
251 cost
= MAX (cost
, move_cost
[m
][i
][*p2
]);
253 for (p1
= ®_class_subclasses
[i
][0];
254 *p1
!= LIM_REG_CLASSES
; p1
++)
255 if (*p1
!= j
&& contains_reg_of_mode
[*p1
][m
])
256 cost
= MAX (cost
, move_cost
[m
][*p1
][j
]);
258 gcc_assert (cost
<= 65535);
259 move_cost
[m
][i
][j
] = cost
;
261 if (reg_class_subset_p ((enum reg_class
) i
, (enum reg_class
) j
))
262 may_move_in_cost
[m
][i
][j
] = 0;
264 may_move_in_cost
[m
][i
][j
] = cost
;
266 if (reg_class_subset_p ((enum reg_class
) j
, (enum reg_class
) i
))
267 may_move_out_cost
[m
][i
][j
] = 0;
269 may_move_out_cost
[m
][i
][j
] = cost
;
273 for (j
= 0; j
< N_REG_CLASSES
; j
++)
275 move_cost
[m
][i
][j
] = 65535;
276 may_move_in_cost
[m
][i
][j
] = 65535;
277 may_move_out_cost
[m
][i
][j
] = 65535;
281 /* We need to save copies of some of the register information which
282 can be munged by command-line switches so we can restore it during
283 subsequent back-end reinitialization. */
284 static char saved_fixed_regs
[FIRST_PSEUDO_REGISTER
];
285 static char saved_call_used_regs
[FIRST_PSEUDO_REGISTER
];
286 #ifdef CALL_REALLY_USED_REGISTERS
287 static char saved_call_really_used_regs
[FIRST_PSEUDO_REGISTER
];
289 static const char *saved_reg_names
[FIRST_PSEUDO_REGISTER
];
291 /* Save the register information. */
293 save_register_info (void)
295 /* Sanity check: make sure the target macros FIXED_REGISTERS and
296 CALL_USED_REGISTERS had the right number of initializers. */
297 gcc_assert (sizeof fixed_regs
== sizeof saved_fixed_regs
);
298 gcc_assert (sizeof call_used_regs
== sizeof saved_call_used_regs
);
299 memcpy (saved_fixed_regs
, fixed_regs
, sizeof fixed_regs
);
300 memcpy (saved_call_used_regs
, call_used_regs
, sizeof call_used_regs
);
302 /* Likewise for call_really_used_regs. */
303 #ifdef CALL_REALLY_USED_REGISTERS
304 gcc_assert (sizeof call_really_used_regs
305 == sizeof saved_call_really_used_regs
);
306 memcpy (saved_call_really_used_regs
, call_really_used_regs
,
307 sizeof call_really_used_regs
);
310 /* And similarly for reg_names. */
311 gcc_assert (sizeof reg_names
== sizeof saved_reg_names
);
312 memcpy (saved_reg_names
, reg_names
, sizeof reg_names
);
315 /* Restore the register information. */
317 restore_register_info (void)
319 memcpy (fixed_regs
, saved_fixed_regs
, sizeof fixed_regs
);
320 memcpy (call_used_regs
, saved_call_used_regs
, sizeof call_used_regs
);
322 #ifdef CALL_REALLY_USED_REGISTERS
323 memcpy (call_really_used_regs
, saved_call_really_used_regs
,
324 sizeof call_really_used_regs
);
327 memcpy (reg_names
, saved_reg_names
, sizeof reg_names
);
330 /* After switches have been processed, which perhaps alter
331 `fixed_regs' and `call_used_regs', convert them to HARD_REG_SETs. */
333 init_reg_sets_1 (void)
336 unsigned int /* enum machine_mode */ m
;
338 restore_register_info ();
340 #ifdef REG_ALLOC_ORDER
341 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
342 inv_reg_alloc_order
[reg_alloc_order
[i
]] = i
;
345 /* Let the target tweak things if necessary. */
347 targetm
.conditional_register_usage ();
349 /* Compute number of hard regs in each class. */
351 memset (reg_class_size
, 0, sizeof reg_class_size
);
352 for (i
= 0; i
< N_REG_CLASSES
; i
++)
354 bool any_nonfixed
= false;
355 for (j
= 0; j
< FIRST_PSEUDO_REGISTER
; j
++)
356 if (TEST_HARD_REG_BIT (reg_class_contents
[i
], j
))
362 class_only_fixed_regs
[i
] = !any_nonfixed
;
365 /* Initialize the table of subunions.
366 reg_class_subunion[I][J] gets the largest-numbered reg-class
367 that is contained in the union of classes I and J. */
369 memset (reg_class_subunion
, 0, sizeof reg_class_subunion
);
370 for (i
= 0; i
< N_REG_CLASSES
; i
++)
372 for (j
= 0; j
< N_REG_CLASSES
; j
++)
377 COPY_HARD_REG_SET (c
, reg_class_contents
[i
]);
378 IOR_HARD_REG_SET (c
, reg_class_contents
[j
]);
379 for (k
= 0; k
< N_REG_CLASSES
; k
++)
380 if (hard_reg_set_subset_p (reg_class_contents
[k
], c
)
381 && !hard_reg_set_subset_p (reg_class_contents
[k
],
383 [(int) reg_class_subunion
[i
][j
]]))
384 reg_class_subunion
[i
][j
] = (enum reg_class
) k
;
388 /* Initialize the table of superunions.
389 reg_class_superunion[I][J] gets the smallest-numbered reg-class
390 containing the union of classes I and J. */
392 memset (reg_class_superunion
, 0, sizeof reg_class_superunion
);
393 for (i
= 0; i
< N_REG_CLASSES
; i
++)
395 for (j
= 0; j
< N_REG_CLASSES
; j
++)
400 COPY_HARD_REG_SET (c
, reg_class_contents
[i
]);
401 IOR_HARD_REG_SET (c
, reg_class_contents
[j
]);
402 for (k
= 0; k
< N_REG_CLASSES
; k
++)
403 if (hard_reg_set_subset_p (c
, reg_class_contents
[k
]))
406 reg_class_superunion
[i
][j
] = (enum reg_class
) k
;
410 /* Initialize the tables of subclasses and superclasses of each reg class.
411 First clear the whole table, then add the elements as they are found. */
413 for (i
= 0; i
< N_REG_CLASSES
; i
++)
415 for (j
= 0; j
< N_REG_CLASSES
; j
++)
416 reg_class_subclasses
[i
][j
] = LIM_REG_CLASSES
;
419 for (i
= 0; i
< N_REG_CLASSES
; i
++)
421 if (i
== (int) NO_REGS
)
424 for (j
= i
+ 1; j
< N_REG_CLASSES
; j
++)
425 if (hard_reg_set_subset_p (reg_class_contents
[i
],
426 reg_class_contents
[j
]))
428 /* Reg class I is a subclass of J.
429 Add J to the table of superclasses of I. */
432 /* Add I to the table of superclasses of J. */
433 p
= ®_class_subclasses
[j
][0];
434 while (*p
!= LIM_REG_CLASSES
) p
++;
435 *p
= (enum reg_class
) i
;
439 /* Initialize "constant" tables. */
441 CLEAR_HARD_REG_SET (fixed_reg_set
);
442 CLEAR_HARD_REG_SET (call_used_reg_set
);
443 CLEAR_HARD_REG_SET (call_fixed_reg_set
);
444 CLEAR_HARD_REG_SET (regs_invalidated_by_call
);
445 if (!regs_invalidated_by_call_regset
)
447 bitmap_obstack_initialize (&persistent_obstack
);
448 regs_invalidated_by_call_regset
= ALLOC_REG_SET (&persistent_obstack
);
451 CLEAR_REG_SET (regs_invalidated_by_call_regset
);
453 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
455 /* call_used_regs must include fixed_regs. */
456 gcc_assert (!fixed_regs
[i
] || call_used_regs
[i
]);
457 #ifdef CALL_REALLY_USED_REGISTERS
458 /* call_used_regs must include call_really_used_regs. */
459 gcc_assert (!call_really_used_regs
[i
] || call_used_regs
[i
]);
463 SET_HARD_REG_BIT (fixed_reg_set
, i
);
465 if (call_used_regs
[i
])
466 SET_HARD_REG_BIT (call_used_reg_set
, i
);
468 /* There are a couple of fixed registers that we know are safe to
469 exclude from being clobbered by calls:
471 The frame pointer is always preserved across calls. The arg
472 pointer is if it is fixed. The stack pointer usually is,
473 unless TARGET_RETURN_POPS_ARGS, in which case an explicit
474 CLOBBER will be present. If we are generating PIC code, the
475 PIC offset table register is preserved across calls, though the
476 target can override that. */
478 if (i
== STACK_POINTER_REGNUM
)
480 else if (global_regs
[i
])
482 SET_HARD_REG_BIT (regs_invalidated_by_call
, i
);
483 SET_REGNO_REG_SET (regs_invalidated_by_call_regset
, i
);
485 else if (i
== FRAME_POINTER_REGNUM
)
487 #if !HARD_FRAME_POINTER_IS_FRAME_POINTER
488 else if (i
== HARD_FRAME_POINTER_REGNUM
)
491 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
492 else if (i
== ARG_POINTER_REGNUM
&& fixed_regs
[i
])
495 else if (!PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
496 && i
== (unsigned) PIC_OFFSET_TABLE_REGNUM
&& fixed_regs
[i
])
498 else if (CALL_REALLY_USED_REGNO_P (i
))
500 SET_HARD_REG_BIT (regs_invalidated_by_call
, i
);
501 SET_REGNO_REG_SET (regs_invalidated_by_call_regset
, i
);
505 COPY_HARD_REG_SET(call_fixed_reg_set
, fixed_reg_set
);
507 /* Preserve global registers if called more than once. */
508 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
512 fixed_regs
[i
] = call_used_regs
[i
] = 1;
513 SET_HARD_REG_BIT (fixed_reg_set
, i
);
514 SET_HARD_REG_BIT (call_used_reg_set
, i
);
515 SET_HARD_REG_BIT (call_fixed_reg_set
, i
);
519 memset (have_regs_of_mode
, 0, sizeof (have_regs_of_mode
));
520 memset (contains_reg_of_mode
, 0, sizeof (contains_reg_of_mode
));
521 for (m
= 0; m
< (unsigned int) MAX_MACHINE_MODE
; m
++)
523 HARD_REG_SET ok_regs
;
524 CLEAR_HARD_REG_SET (ok_regs
);
525 for (j
= 0; j
< FIRST_PSEUDO_REGISTER
; j
++)
526 if (!fixed_regs
[j
] && HARD_REGNO_MODE_OK (j
, (enum machine_mode
) m
))
527 SET_HARD_REG_BIT (ok_regs
, j
);
529 for (i
= 0; i
< N_REG_CLASSES
; i
++)
530 if (((unsigned) CLASS_MAX_NREGS ((enum reg_class
) i
,
531 (enum machine_mode
) m
)
532 <= reg_class_size
[i
])
533 && hard_reg_set_intersect_p (ok_regs
, reg_class_contents
[i
]))
535 contains_reg_of_mode
[i
][m
] = 1;
536 have_regs_of_mode
[m
] = 1;
540 /* Reset move_cost and friends, making sure we only free shared
541 table entries once. */
542 for (i
= 0; i
< MAX_MACHINE_MODE
; i
++)
545 for (j
= 0; j
< i
&& move_cost
[i
] != move_cost
[j
]; j
++)
550 free (may_move_in_cost
[i
]);
551 free (may_move_out_cost
[i
]);
554 memset (move_cost
, 0, sizeof move_cost
);
555 memset (may_move_in_cost
, 0, sizeof may_move_in_cost
);
556 memset (may_move_out_cost
, 0, sizeof may_move_out_cost
);
557 last_mode_for_init_move_cost
= -1;
560 /* Compute the table of register modes.
561 These values are used to record death information for individual registers
562 (as opposed to a multi-register mode).
563 This function might be invoked more than once, if the target has support
564 for changing register usage conventions on a per-function basis.
567 init_reg_modes_target (void)
571 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
572 for (j
= 0; j
< MAX_MACHINE_MODE
; j
++)
573 hard_regno_nregs
[i
][j
] = HARD_REGNO_NREGS(i
, (enum machine_mode
)j
);
575 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
577 reg_raw_mode
[i
] = choose_hard_reg_mode (i
, 1, false);
579 /* If we couldn't find a valid mode, just use the previous mode.
580 ??? One situation in which we need to do this is on the mips where
581 HARD_REGNO_NREGS (fpreg, [SD]Fmode) returns 2. Ideally we'd like
582 to use DF mode for the even registers and VOIDmode for the odd
583 (for the cpu models where the odd ones are inaccessible). */
584 if (reg_raw_mode
[i
] == VOIDmode
)
585 reg_raw_mode
[i
] = i
== 0 ? word_mode
: reg_raw_mode
[i
-1];
589 /* Finish initializing the register sets and initialize the register modes.
590 This function might be invoked more than once, if the target has support
591 for changing register usage conventions on a per-function basis.
596 /* This finishes what was started by init_reg_sets, but couldn't be done
597 until after register usage was specified. */
601 /* The same as previous function plus initializing IRA. */
606 /* caller_save needs to be re-initialized. */
607 caller_save_initialized_p
= false;
611 /* Initialize some fake stack-frame MEM references for use in
612 memory_move_secondary_cost. */
614 init_fake_stack_mems (void)
618 for (i
= 0; i
< MAX_MACHINE_MODE
; i
++)
619 top_of_stack
[i
] = gen_rtx_MEM ((enum machine_mode
) i
, stack_pointer_rtx
);
623 /* Compute cost of moving data from a register of class FROM to one of
627 register_move_cost (enum machine_mode mode
, reg_class_t from
, reg_class_t to
)
629 return targetm
.register_move_cost (mode
, from
, to
);
632 /* Compute cost of moving registers to/from memory. */
634 memory_move_cost (enum machine_mode mode
, enum reg_class rclass
, bool in
)
636 return targetm
.memory_move_cost (mode
, rclass
, in
);
639 /* Compute extra cost of moving registers to/from memory due to reloads.
640 Only needed if secondary reloads are required for memory moves. */
642 memory_move_secondary_cost (enum machine_mode mode
, reg_class_t rclass
,
645 reg_class_t altclass
;
646 int partial_cost
= 0;
647 /* We need a memory reference to feed to SECONDARY... macros. */
648 /* mem may be unused even if the SECONDARY_ macros are defined. */
649 rtx mem ATTRIBUTE_UNUSED
= top_of_stack
[(int) mode
];
651 altclass
= secondary_reload_class (in
? 1 : 0, rclass
, mode
, mem
);
653 if (altclass
== NO_REGS
)
657 partial_cost
= register_move_cost (mode
, altclass
, rclass
);
659 partial_cost
= register_move_cost (mode
, rclass
, altclass
);
661 if (rclass
== altclass
)
662 /* This isn't simply a copy-to-temporary situation. Can't guess
663 what it is, so TARGET_MEMORY_MOVE_COST really ought not to be
664 calling here in that case.
666 I'm tempted to put in an assert here, but returning this will
667 probably only give poor estimates, which is what we would've
668 had before this code anyways. */
671 /* Check if the secondary reload register will also need a
673 return memory_move_secondary_cost (mode
, altclass
, in
) + partial_cost
;
676 /* Return a machine mode that is legitimate for hard reg REGNO and large
677 enough to save nregs. If we can't find one, return VOIDmode.
678 If CALL_SAVED is true, only consider modes that are call saved. */
680 choose_hard_reg_mode (unsigned int regno ATTRIBUTE_UNUSED
,
681 unsigned int nregs
, bool call_saved
)
683 unsigned int /* enum machine_mode */ m
;
684 enum machine_mode found_mode
= VOIDmode
, mode
;
686 /* We first look for the largest integer mode that can be validly
687 held in REGNO. If none, we look for the largest floating-point mode.
688 If we still didn't find a valid mode, try CCmode. */
690 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_INT
);
692 mode
= GET_MODE_WIDER_MODE (mode
))
693 if ((unsigned) hard_regno_nregs
[regno
][mode
] == nregs
694 && HARD_REGNO_MODE_OK (regno
, mode
)
695 && (! call_saved
|| ! HARD_REGNO_CALL_PART_CLOBBERED (regno
, mode
)))
698 if (found_mode
!= VOIDmode
)
701 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_FLOAT
);
703 mode
= GET_MODE_WIDER_MODE (mode
))
704 if ((unsigned) hard_regno_nregs
[regno
][mode
] == nregs
705 && HARD_REGNO_MODE_OK (regno
, mode
)
706 && (! call_saved
|| ! HARD_REGNO_CALL_PART_CLOBBERED (regno
, mode
)))
709 if (found_mode
!= VOIDmode
)
712 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_VECTOR_FLOAT
);
714 mode
= GET_MODE_WIDER_MODE (mode
))
715 if ((unsigned) hard_regno_nregs
[regno
][mode
] == nregs
716 && HARD_REGNO_MODE_OK (regno
, mode
)
717 && (! call_saved
|| ! HARD_REGNO_CALL_PART_CLOBBERED (regno
, mode
)))
720 if (found_mode
!= VOIDmode
)
723 for (mode
= GET_CLASS_NARROWEST_MODE (MODE_VECTOR_INT
);
725 mode
= GET_MODE_WIDER_MODE (mode
))
726 if ((unsigned) hard_regno_nregs
[regno
][mode
] == nregs
727 && HARD_REGNO_MODE_OK (regno
, mode
)
728 && (! call_saved
|| ! HARD_REGNO_CALL_PART_CLOBBERED (regno
, mode
)))
731 if (found_mode
!= VOIDmode
)
734 /* Iterate over all of the CCmodes. */
735 for (m
= (unsigned int) CCmode
; m
< (unsigned int) NUM_MACHINE_MODES
; ++m
)
737 mode
= (enum machine_mode
) m
;
738 if ((unsigned) hard_regno_nregs
[regno
][mode
] == nregs
739 && HARD_REGNO_MODE_OK (regno
, mode
)
740 && (! call_saved
|| ! HARD_REGNO_CALL_PART_CLOBBERED (regno
, mode
)))
744 /* We can't find a mode valid for this register. */
748 /* Specify the usage characteristics of the register named NAME.
749 It should be a fixed register if FIXED and a
750 call-used register if CALL_USED. */
752 fix_register (const char *name
, int fixed
, int call_used
)
757 /* Decode the name and update the primary form of
758 the register info. */
760 if ((reg
= decode_reg_name_and_count (name
, &nregs
)) >= 0)
762 gcc_assert (nregs
>= 1);
763 for (i
= reg
; i
< reg
+ nregs
; i
++)
765 if ((i
== STACK_POINTER_REGNUM
766 #ifdef HARD_FRAME_POINTER_REGNUM
767 || i
== HARD_FRAME_POINTER_REGNUM
769 || i
== FRAME_POINTER_REGNUM
772 && (fixed
== 0 || call_used
== 0))
780 error ("can%'t use %qs as a call-saved register", name
);
784 error ("can%'t use %qs as a call-used register", name
);
796 error ("can%'t use %qs as a fixed register", name
);
811 fixed_regs
[i
] = fixed
;
812 call_used_regs
[i
] = call_used
;
813 #ifdef CALL_REALLY_USED_REGISTERS
815 call_really_used_regs
[i
] = call_used
;
822 warning (0, "unknown register name: %s", name
);
826 /* Mark register number I as global. */
828 globalize_reg (int i
)
831 if (IN_RANGE (i
, FIRST_STACK_REG
, LAST_STACK_REG
))
833 error ("stack register used for global register variable");
838 if (fixed_regs
[i
] == 0 && no_global_reg_vars
)
839 error ("global register variable follows a function definition");
843 warning (0, "register used for two global register variables");
847 if (call_used_regs
[i
] && ! fixed_regs
[i
])
848 warning (0, "call-clobbered register used for global register variable");
852 /* If we're globalizing the frame pointer, we need to set the
853 appropriate regs_invalidated_by_call bit, even if it's already
854 set in fixed_regs. */
855 if (i
!= STACK_POINTER_REGNUM
)
857 SET_HARD_REG_BIT (regs_invalidated_by_call
, i
);
858 SET_REGNO_REG_SET (regs_invalidated_by_call_regset
, i
);
861 /* If already fixed, nothing else to do. */
865 fixed_regs
[i
] = call_used_regs
[i
] = 1;
866 #ifdef CALL_REALLY_USED_REGISTERS
867 call_really_used_regs
[i
] = 1;
870 SET_HARD_REG_BIT (fixed_reg_set
, i
);
871 SET_HARD_REG_BIT (call_used_reg_set
, i
);
872 SET_HARD_REG_BIT (call_fixed_reg_set
, i
);
878 /* Structure used to record preferences of given pseudo. */
881 /* (enum reg_class) prefclass is the preferred class. May be
882 NO_REGS if no class is better than memory. */
885 /* altclass is a register class that we should use for allocating
886 pseudo if no register in the preferred class is available.
887 If no register in this class is available, memory is preferred.
889 It might appear to be more general to have a bitmask of classes here,
890 but since it is recommended that there be a class corresponding to the
891 union of most major pair of classes, that generality is not required. */
894 /* coverclass is a register class that IRA uses for allocating
899 /* Record preferences of each pseudo. This is available after RA is
901 static struct reg_pref
*reg_pref
;
903 /* Current size of reg_info. */
904 static int reg_info_size
;
906 /* Return the reg_class in which pseudo reg number REGNO is best allocated.
907 This function is sometimes called before the info has been computed.
908 When that happens, just return GENERAL_REGS, which is innocuous. */
910 reg_preferred_class (int regno
)
915 return (enum reg_class
) reg_pref
[regno
].prefclass
;
919 reg_alternate_class (int regno
)
924 return (enum reg_class
) reg_pref
[regno
].altclass
;
927 /* Return the reg_class which is used by IRA for its allocation. */
929 reg_cover_class (int regno
)
934 return (enum reg_class
) reg_pref
[regno
].coverclass
;
939 /* Allocate space for reg info. */
941 allocate_reg_info (void)
943 reg_info_size
= max_reg_num ();
944 gcc_assert (! reg_pref
&& ! reg_renumber
);
945 reg_renumber
= XNEWVEC (short, reg_info_size
);
946 reg_pref
= XCNEWVEC (struct reg_pref
, reg_info_size
);
947 memset (reg_renumber
, -1, reg_info_size
* sizeof (short));
951 /* Resize reg info. The new elements will be uninitialized. Return
952 TRUE if new elements (for new pseudos) were added. */
954 resize_reg_info (void)
958 if (reg_pref
== NULL
)
960 allocate_reg_info ();
963 if (reg_info_size
== max_reg_num ())
966 reg_info_size
= max_reg_num ();
967 gcc_assert (reg_pref
&& reg_renumber
);
968 reg_renumber
= XRESIZEVEC (short, reg_renumber
, reg_info_size
);
969 reg_pref
= XRESIZEVEC (struct reg_pref
, reg_pref
, reg_info_size
);
970 memset (reg_pref
+ old
, -1,
971 (reg_info_size
- old
) * sizeof (struct reg_pref
));
972 memset (reg_renumber
+ old
, -1, (reg_info_size
- old
) * sizeof (short));
977 /* Free up the space allocated by allocate_reg_info. */
994 /* Initialize some global data for this pass. */
999 df_compute_regs_ever_live (true);
1001 /* This prevents dump_flow_info from losing if called
1002 before reginfo is run. */
1004 /* No more global register variables may be declared. */
1005 no_global_reg_vars
= 1;
1009 struct rtl_opt_pass pass_reginfo_init
=
1013 "reginfo", /* name */
1015 reginfo_init
, /* execute */
1018 0, /* static_pass_number */
1019 TV_NONE
, /* tv_id */
1020 0, /* properties_required */
1021 0, /* properties_provided */
1022 0, /* properties_destroyed */
1023 0, /* todo_flags_start */
1024 0 /* todo_flags_finish */
1030 /* Set up preferred, alternate, and cover classes for REGNO as
1031 PREFCLASS, ALTCLASS, and COVERCLASS. */
1033 setup_reg_classes (int regno
,
1034 enum reg_class prefclass
, enum reg_class altclass
,
1035 enum reg_class coverclass
)
1037 if (reg_pref
== NULL
)
1039 gcc_assert (reg_info_size
== max_reg_num ());
1040 reg_pref
[regno
].prefclass
= prefclass
;
1041 reg_pref
[regno
].altclass
= altclass
;
1042 reg_pref
[regno
].coverclass
= coverclass
;
1046 /* This is the `regscan' pass of the compiler, run just before cse and
1047 again just before loop. It finds the first and last use of each
1050 static void reg_scan_mark_refs (rtx
, rtx
);
1053 reg_scan (rtx f
, unsigned int nregs ATTRIBUTE_UNUSED
)
1057 timevar_push (TV_REG_SCAN
);
1059 for (insn
= f
; insn
; insn
= NEXT_INSN (insn
))
1062 reg_scan_mark_refs (PATTERN (insn
), insn
);
1063 if (REG_NOTES (insn
))
1064 reg_scan_mark_refs (REG_NOTES (insn
), insn
);
1067 timevar_pop (TV_REG_SCAN
);
1071 /* X is the expression to scan. INSN is the insn it appears in.
1072 NOTE_FLAG is nonzero if X is from INSN's notes rather than its body.
1073 We should only record information for REGs with numbers
1074 greater than or equal to MIN_REGNO. */
1076 reg_scan_mark_refs (rtx x
, rtx insn
)
1084 code
= GET_CODE (x
);
1103 reg_scan_mark_refs (XEXP (x
, 0), insn
);
1105 reg_scan_mark_refs (XEXP (x
, 1), insn
);
1110 reg_scan_mark_refs (XEXP (x
, 1), insn
);
1114 if (MEM_P (XEXP (x
, 0)))
1115 reg_scan_mark_refs (XEXP (XEXP (x
, 0), 0), insn
);
1119 /* Count a set of the destination if it is a register. */
1120 for (dest
= SET_DEST (x
);
1121 GET_CODE (dest
) == SUBREG
|| GET_CODE (dest
) == STRICT_LOW_PART
1122 || GET_CODE (dest
) == ZERO_EXTEND
;
1123 dest
= XEXP (dest
, 0))
1126 /* If this is setting a pseudo from another pseudo or the sum of a
1127 pseudo and a constant integer and the other pseudo is known to be
1128 a pointer, set the destination to be a pointer as well.
1130 Likewise if it is setting the destination from an address or from a
1131 value equivalent to an address or to the sum of an address and
1134 But don't do any of this if the pseudo corresponds to a user
1135 variable since it should have already been set as a pointer based
1138 if (REG_P (SET_DEST (x
))
1139 && REGNO (SET_DEST (x
)) >= FIRST_PSEUDO_REGISTER
1140 /* If the destination pseudo is set more than once, then other
1141 sets might not be to a pointer value (consider access to a
1142 union in two threads of control in the presence of global
1143 optimizations). So only set REG_POINTER on the destination
1144 pseudo if this is the only set of that pseudo. */
1145 && DF_REG_DEF_COUNT (REGNO (SET_DEST (x
))) == 1
1146 && ! REG_USERVAR_P (SET_DEST (x
))
1147 && ! REG_POINTER (SET_DEST (x
))
1148 && ((REG_P (SET_SRC (x
))
1149 && REG_POINTER (SET_SRC (x
)))
1150 || ((GET_CODE (SET_SRC (x
)) == PLUS
1151 || GET_CODE (SET_SRC (x
)) == LO_SUM
)
1152 && CONST_INT_P (XEXP (SET_SRC (x
), 1))
1153 && REG_P (XEXP (SET_SRC (x
), 0))
1154 && REG_POINTER (XEXP (SET_SRC (x
), 0)))
1155 || GET_CODE (SET_SRC (x
)) == CONST
1156 || GET_CODE (SET_SRC (x
)) == SYMBOL_REF
1157 || GET_CODE (SET_SRC (x
)) == LABEL_REF
1158 || (GET_CODE (SET_SRC (x
)) == HIGH
1159 && (GET_CODE (XEXP (SET_SRC (x
), 0)) == CONST
1160 || GET_CODE (XEXP (SET_SRC (x
), 0)) == SYMBOL_REF
1161 || GET_CODE (XEXP (SET_SRC (x
), 0)) == LABEL_REF
))
1162 || ((GET_CODE (SET_SRC (x
)) == PLUS
1163 || GET_CODE (SET_SRC (x
)) == LO_SUM
)
1164 && (GET_CODE (XEXP (SET_SRC (x
), 1)) == CONST
1165 || GET_CODE (XEXP (SET_SRC (x
), 1)) == SYMBOL_REF
1166 || GET_CODE (XEXP (SET_SRC (x
), 1)) == LABEL_REF
))
1167 || ((note
= find_reg_note (insn
, REG_EQUAL
, 0)) != 0
1168 && (GET_CODE (XEXP (note
, 0)) == CONST
1169 || GET_CODE (XEXP (note
, 0)) == SYMBOL_REF
1170 || GET_CODE (XEXP (note
, 0)) == LABEL_REF
))))
1171 REG_POINTER (SET_DEST (x
)) = 1;
1173 /* If this is setting a register from a register or from a simple
1174 conversion of a register, propagate REG_EXPR. */
1175 if (REG_P (dest
) && !REG_ATTRS (dest
))
1177 rtx src
= SET_SRC (x
);
1179 while (GET_CODE (src
) == SIGN_EXTEND
1180 || GET_CODE (src
) == ZERO_EXTEND
1181 || GET_CODE (src
) == TRUNCATE
1182 || (GET_CODE (src
) == SUBREG
&& subreg_lowpart_p (src
)))
1183 src
= XEXP (src
, 0);
1185 set_reg_attrs_from_value (dest
, src
);
1188 /* ... fall through ... */
1192 const char *fmt
= GET_RTX_FORMAT (code
);
1194 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1197 reg_scan_mark_refs (XEXP (x
, i
), insn
);
1198 else if (fmt
[i
] == 'E' && XVEC (x
, i
) != 0)
1201 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
1202 reg_scan_mark_refs (XVECEXP (x
, i
, j
), insn
);
1210 /* Return nonzero if C1 is a subset of C2, i.e., if every register in C1
1213 reg_class_subset_p (reg_class_t c1
, reg_class_t c2
)
1217 || hard_reg_set_subset_p (reg_class_contents
[(int) c1
],
1218 reg_class_contents
[(int) c2
]));
1221 /* Return nonzero if there is a register that is in both C1 and C2. */
1223 reg_classes_intersect_p (reg_class_t c1
, reg_class_t c2
)
1228 || hard_reg_set_intersect_p (reg_class_contents
[(int) c1
],
1229 reg_class_contents
[(int) c2
]));
1234 /* Passes for keeping and updating info about modes of registers
1235 inside subregisters. */
1237 #ifdef CANNOT_CHANGE_MODE_CLASS
1239 struct subregs_of_mode_node
1242 unsigned char modes
[MAX_MACHINE_MODE
];
1245 static htab_t subregs_of_mode
;
1248 som_hash (const void *x
)
1250 const struct subregs_of_mode_node
*const a
=
1251 (const struct subregs_of_mode_node
*) x
;
1256 som_eq (const void *x
, const void *y
)
1258 const struct subregs_of_mode_node
*const a
=
1259 (const struct subregs_of_mode_node
*) x
;
1260 const struct subregs_of_mode_node
*const b
=
1261 (const struct subregs_of_mode_node
*) y
;
1262 return a
->block
== b
->block
;
1266 record_subregs_of_mode (rtx subreg
)
1268 struct subregs_of_mode_node dummy
, *node
;
1269 enum machine_mode mode
;
1273 if (!REG_P (SUBREG_REG (subreg
)))
1276 regno
= REGNO (SUBREG_REG (subreg
));
1277 mode
= GET_MODE (subreg
);
1279 if (regno
< FIRST_PSEUDO_REGISTER
)
1282 dummy
.block
= regno
& -8;
1283 slot
= htab_find_slot_with_hash (subregs_of_mode
, &dummy
,
1284 dummy
.block
, INSERT
);
1285 node
= (struct subregs_of_mode_node
*) *slot
;
1288 node
= XCNEW (struct subregs_of_mode_node
);
1289 node
->block
= regno
& -8;
1293 node
->modes
[mode
] |= 1 << (regno
& 7);
1296 /* Call record_subregs_of_mode for all the subregs in X. */
1298 find_subregs_of_mode (rtx x
)
1300 enum rtx_code code
= GET_CODE (x
);
1301 const char * const fmt
= GET_RTX_FORMAT (code
);
1305 record_subregs_of_mode (x
);
1307 /* Time for some deep diving. */
1308 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1311 find_subregs_of_mode (XEXP (x
, i
));
1312 else if (fmt
[i
] == 'E')
1315 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
1316 find_subregs_of_mode (XVECEXP (x
, i
, j
));
1322 init_subregs_of_mode (void)
1327 if (subregs_of_mode
)
1328 htab_empty (subregs_of_mode
);
1330 subregs_of_mode
= htab_create (100, som_hash
, som_eq
, free
);
1333 FOR_BB_INSNS (bb
, insn
)
1335 find_subregs_of_mode (PATTERN (insn
));
1338 /* Return 1 if REGNO has had an invalid mode change in CLASS from FROM
1341 invalid_mode_change_p (unsigned int regno
,
1342 enum reg_class rclass ATTRIBUTE_UNUSED
,
1343 enum machine_mode from
)
1345 struct subregs_of_mode_node dummy
, *node
;
1349 gcc_assert (subregs_of_mode
);
1350 dummy
.block
= regno
& -8;
1351 node
= (struct subregs_of_mode_node
*)
1352 htab_find_with_hash (subregs_of_mode
, &dummy
, dummy
.block
);
1356 mask
= 1 << (regno
& 7);
1357 for (to
= VOIDmode
; to
< NUM_MACHINE_MODES
; to
++)
1358 if (node
->modes
[to
] & mask
)
1359 if (CANNOT_CHANGE_MODE_CLASS (from
, (enum machine_mode
) to
, rclass
))
1366 finish_subregs_of_mode (void)
1368 htab_delete (subregs_of_mode
);
1369 subregs_of_mode
= 0;
1373 init_subregs_of_mode (void)
1377 finish_subregs_of_mode (void)
1381 #endif /* CANNOT_CHANGE_MODE_CLASS */