1 /* Dataflow support routines.
2 Copyright (C) 1999, 2000, 2001 Free Software Foundation, Inc.
3 Contributed by Michael P. Hayes (m.hayes@elec.canterbury.ac.nz,
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 2, 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 COPYING. If not, write to the Free
20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
26 This file provides some dataflow routines for computing reaching defs,
27 upward exposed uses, live variables, def-use chains, and use-def
28 chains. The global dataflow is performed using simple iterative
29 methods with a worklist and could be sped up by ordering the blocks
30 with a depth first search order.
32 A `struct ref' data structure (ref) is allocated for every register
33 reference (def or use) and this records the insn and bb the ref is
34 found within. The refs are linked together in chains of uses and defs
35 for each insn and for each register. Each ref also has a chain field
36 that links all the use refs for a def or all the def refs for a use.
37 This is used to create use-def or def-use chains.
42 Here's an example of using the dataflow routines.
48 df_analyse (df, 0, DF_ALL);
50 df_dump (df, DF_ALL, stderr);
55 df_init simply creates a poor man's object (df) that needs to be
56 passed to all the dataflow routines. df_finish destroys this
57 object and frees up any allocated memory.
59 df_analyse performs the following:
61 1. Records defs and uses by scanning the insns in each basic block
62 or by scanning the insns queued by df_insn_modify.
63 2. Links defs and uses into insn-def and insn-use chains.
64 3. Links defs and uses into reg-def and reg-use chains.
65 4. Assigns LUIDs to each insn (for modified blocks).
66 5. Calculates local reaching definitions.
67 6. Calculates global reaching definitions.
68 7. Creates use-def chains.
69 8. Calculates local reaching uses (upwards exposed uses).
70 9. Calculates global reaching uses.
71 10. Creates def-use chains.
72 11. Calculates local live registers.
73 12. Calculates global live registers.
74 13. Calculates register lifetimes and determines local registers.
79 Note that the dataflow information is not updated for every newly
80 deleted or created insn. If the dataflow information requires
81 updating then all the changed, new, or deleted insns needs to be
82 marked with df_insn_modify (or df_insns_modify) either directly or
83 indirectly (say through calling df_insn_delete). df_insn_modify
84 marks all the modified insns to get processed the next time df_analyse
87 Beware that tinkering with insns may invalidate the dataflow information.
88 The philosophy behind these routines is that once the dataflow
89 information has been gathered, the user should store what they require
90 before they tinker with any insn. Once a reg is replaced, for example,
91 then the reg-def/reg-use chains will point to the wrong place. Once a
92 whole lot of changes have been made, df_analyse can be called again
93 to update the dataflow information. Currently, this is not very smart
94 with regard to propagating changes to the dataflow so it should not
100 The basic object is a REF (reference) and this may either be a DEF
101 (definition) or a USE of a register.
103 These are linked into a variety of lists; namely reg-def, reg-use,
104 insn-def, insn-use, def-use, and use-def lists. For example,
105 the reg-def lists contain all the refs that define a given register
106 while the insn-use lists contain all the refs used by an insn.
108 Note that the reg-def and reg-use chains are generally short (except for the
109 hard registers) and thus it is much faster to search these chains
110 rather than searching the def or use bitmaps.
112 If the insns are in SSA form then the reg-def and use-def lists
113 should only contain the single defining ref.
117 1) Incremental dataflow analysis.
119 Note that if a loop invariant insn is hoisted (or sunk), we do not
120 need to change the def-use or use-def chains. All we have to do is to
121 change the bb field for all the associated defs and uses and to
122 renumber the LUIDs for the original and new basic blocks of the insn.
124 When shadowing loop mems we create new uses and defs for new pseudos
125 so we do not affect the existing dataflow information.
127 My current strategy is to queue up all modified, created, or deleted
128 insns so when df_analyse is called we can easily determine all the new
129 or deleted refs. Currently the global dataflow information is
130 recomputed from scratch but this could be propagated more efficiently.
132 2) Improved global data flow computation using depth first search.
134 3) Reduced memory requirements.
136 We could operate a pool of ref structures. When a ref is deleted it
137 gets returned to the pool (say by linking on to a chain of free refs).
138 This will require a pair of bitmaps for defs and uses so that we can
139 tell which ones have been changed. Alternatively, we could
140 periodically squeeze the def and use tables and associated bitmaps and
141 renumber the def and use ids.
143 4) Ordering of reg-def and reg-use lists.
145 Should the first entry in the def list be the first def (within a BB)?
146 Similarly, should the first entry in the use list be the last use
149 5) Working with a sub-CFG.
151 Often the whole CFG does not need to be analysed, for example,
152 when optimising a loop, only certain registers are of interest.
153 Perhaps there should be a bitmap argument to df_analyse to specify
154 which registers should be analysed? */
156 #define HANDLE_SUBREG
161 #include "insn-config.h"
163 #include "function.h"
166 #include "hard-reg-set.h"
167 #include "basic-block.h"
172 #define FOR_ALL_BBS(BB, CODE) \
175 for (node_ = 0; node_ < n_basic_blocks; node_++) \
176 {(BB) = BASIC_BLOCK (node_); CODE;};} while (0)
178 #define FOR_EACH_BB_IN_BITMAP(BITMAP, MIN, BB, CODE) \
180 unsigned int node_; \
181 EXECUTE_IF_SET_IN_BITMAP (BITMAP, MIN, node_, \
182 {(BB) = BASIC_BLOCK (node_); CODE;});} while (0)
184 #define FOR_EACH_BB_IN_BITMAP_REV(BITMAP, MIN, BB, CODE) \
186 unsigned int node_; \
187 EXECUTE_IF_SET_IN_BITMAP_REV (BITMAP, node_, \
188 {(BB) = BASIC_BLOCK (node_); CODE;});} while (0)
190 #define FOR_EACH_BB_IN_SBITMAP(BITMAP, MIN, BB, CODE) \
192 unsigned int node_; \
193 EXECUTE_IF_SET_IN_SBITMAP (BITMAP, MIN, node_, \
194 {(BB) = BASIC_BLOCK (node_); CODE;});} while (0)
196 #define obstack_chunk_alloc xmalloc
197 #define obstack_chunk_free free
199 static struct obstack df_ref_obstack;
200 static struct df *ddf;
202 static void df_reg_table_realloc PARAMS((struct df *, int));
204 static void df_def_table_realloc PARAMS((struct df *, int));
206 static void df_insn_table_realloc PARAMS((struct df *, int));
207 static void df_bitmaps_alloc PARAMS((struct df *, int));
208 static void df_bitmaps_free PARAMS((struct df *, int));
209 static void df_free PARAMS((struct df *));
210 static void df_alloc PARAMS((struct df *, int));
212 static rtx df_reg_clobber_gen PARAMS((unsigned int));
213 static rtx df_reg_use_gen PARAMS((unsigned int));
215 static inline struct df_link *df_link_create PARAMS((struct ref *,
217 static struct df_link *df_ref_unlink PARAMS((struct df_link **, struct ref *));
218 static void df_def_unlink PARAMS((struct df *, struct ref *));
219 static void df_use_unlink PARAMS((struct df *, struct ref *));
220 static void df_insn_refs_unlink PARAMS ((struct df *, basic_block, rtx));
222 static void df_bb_refs_unlink PARAMS ((struct df *, basic_block));
223 static void df_refs_unlink PARAMS ((struct df *, bitmap));
226 static struct ref *df_ref_create PARAMS((struct df *,
227 rtx, rtx *, basic_block, rtx,
229 static void df_ref_record_1 PARAMS((struct df *, rtx, rtx *,
230 basic_block, rtx, enum df_ref_type));
231 static void df_ref_record PARAMS((struct df *, rtx, rtx *,
232 basic_block bb, rtx, enum df_ref_type));
233 static void df_def_record_1 PARAMS((struct df *, rtx, basic_block, rtx));
234 static void df_defs_record PARAMS((struct df *, rtx, basic_block, rtx));
235 static void df_uses_record PARAMS((struct df *, rtx *,
236 enum df_ref_type, basic_block, rtx));
237 static void df_insn_refs_record PARAMS((struct df *, basic_block, rtx));
238 static void df_bb_refs_record PARAMS((struct df *, basic_block));
239 static void df_refs_record PARAMS((struct df *, bitmap));
241 static int df_visit_next PARAMS ((struct df *, sbitmap));
242 static void df_bb_reg_def_chain_create PARAMS((struct df *, basic_block));
243 static void df_reg_def_chain_create PARAMS((struct df *, bitmap));
244 static void df_bb_reg_use_chain_create PARAMS((struct df *, basic_block));
245 static void df_reg_use_chain_create PARAMS((struct df *, bitmap));
246 static void df_bb_du_chain_create PARAMS((struct df *, basic_block, bitmap));
247 static void df_du_chain_create PARAMS((struct df *, bitmap));
248 static void df_bb_ud_chain_create PARAMS((struct df *, basic_block));
249 static void df_ud_chain_create PARAMS((struct df *, bitmap));
250 static void df_rd_global_compute PARAMS((struct df *, bitmap));
251 static void df_ru_global_compute PARAMS((struct df *, bitmap));
252 static void df_lr_global_compute PARAMS((struct df *, bitmap));
253 static void df_bb_rd_local_compute PARAMS((struct df *, basic_block));
254 static void df_rd_local_compute PARAMS((struct df *, bitmap));
255 static void df_bb_ru_local_compute PARAMS((struct df *, basic_block));
256 static void df_ru_local_compute PARAMS((struct df *, bitmap));
257 static void df_bb_lr_local_compute PARAMS((struct df *, basic_block));
258 static void df_lr_local_compute PARAMS((struct df *, bitmap));
259 static void df_bb_reg_info_compute PARAMS((struct df *, basic_block, bitmap));
260 static void df_reg_info_compute PARAMS((struct df *, bitmap));
262 static int df_bb_luids_set PARAMS((struct df *df, basic_block));
263 static int df_luids_set PARAMS((struct df *df, bitmap));
265 static int df_modified_p PARAMS ((struct df *, bitmap));
266 static int df_refs_queue PARAMS ((struct df *));
267 static int df_refs_process PARAMS ((struct df *));
268 static int df_bb_refs_update PARAMS ((struct df *, basic_block));
269 static int df_refs_update PARAMS ((struct df *));
270 static void df_analyse_1 PARAMS((struct df *, bitmap, int, int));
272 static void df_insns_modify PARAMS((struct df *, basic_block,
274 static int df_rtx_mem_replace PARAMS ((rtx *, void *));
275 static int df_rtx_reg_replace PARAMS ((rtx *, void *));
276 void df_refs_reg_replace PARAMS ((struct df *, bitmap,
277 struct df_link *, rtx, rtx));
279 static int df_def_dominates_all_uses_p PARAMS((struct df *, struct ref *def));
280 static int df_def_dominates_uses_p PARAMS((struct df *,
281 struct ref *def, bitmap));
282 static struct ref *df_bb_regno_last_use_find PARAMS((struct df *, basic_block,
284 static struct ref *df_bb_regno_first_def_find PARAMS((struct df *, basic_block,
286 static struct ref *df_bb_insn_regno_last_use_find PARAMS((struct df *,
289 static struct ref *df_bb_insn_regno_first_def_find PARAMS((struct df *,
293 static void df_chain_dump PARAMS((struct df_link *, FILE *file));
294 static void df_chain_dump_regno PARAMS((struct df_link *, FILE *file));
295 static void df_regno_debug PARAMS ((struct df *, unsigned int, FILE *));
296 static void df_ref_debug PARAMS ((struct df *, struct ref *, FILE *));
299 /* Local memory allocation/deallocation routines. */
302 /* Increase the insn info table by SIZE more elements. */
304 df_insn_table_realloc (df, size)
308 /* Make table 25 percent larger by default. */
310 size = df->insn_size / 4;
312 size += df->insn_size;
314 df->insns = (struct insn_info *)
315 xrealloc (df->insns, size * sizeof (struct insn_info));
317 memset (df->insns + df->insn_size, 0,
318 (size - df->insn_size) * sizeof (struct insn_info));
320 df->insn_size = size;
322 if (! df->insns_modified)
324 df->insns_modified = BITMAP_XMALLOC ();
325 bitmap_zero (df->insns_modified);
330 /* Increase the reg info table by SIZE more elements. */
332 df_reg_table_realloc (df, size)
336 /* Make table 25 percent larger by default. */
338 size = df->reg_size / 4;
340 size += df->reg_size;
342 df->regs = (struct reg_info *)
343 xrealloc (df->regs, size * sizeof (struct reg_info));
345 /* Zero the new entries. */
346 memset (df->regs + df->reg_size, 0,
347 (size - df->reg_size) * sizeof (struct reg_info));
354 /* Not currently used. */
356 df_def_table_realloc (df, size)
363 /* Make table 25 percent larger by default. */
365 size = df->def_size / 4;
367 df->def_size += size;
368 df->defs = xrealloc (df->defs,
369 df->def_size * sizeof (*df->defs));
371 /* Allocate a new block of memory and link into list of blocks
372 that will need to be freed later. */
374 refs = xmalloc (size * sizeof (*refs));
376 /* Link all the new refs together, overloading the chain field. */
377 for (i = 0; i < size - 1; i++)
378 refs[i].chain = (struct df_link *)(refs + i + 1);
379 refs[size - 1].chain = 0;
385 /* Allocate bitmaps for each basic block. */
387 df_bitmaps_alloc (df, flags)
394 /* Free the bitmaps if they need resizing. */
395 if ((flags & DF_LR) && df->n_regs < (unsigned int)max_reg_num ())
396 dflags |= DF_LR | DF_RU;
397 if ((flags & DF_RU) && df->n_uses < df->use_id)
399 if ((flags & DF_RD) && df->n_defs < df->def_id)
403 df_bitmaps_free (df, dflags);
405 df->n_defs = df->def_id;
406 df->n_uses = df->use_id;
408 for (i = 0; i < df->n_bbs; i++)
410 basic_block bb = BASIC_BLOCK (i);
411 struct bb_info *bb_info = DF_BB_INFO (df, bb);
413 if (flags & DF_RD && ! bb_info->rd_in)
415 /* Allocate bitmaps for reaching definitions. */
416 bb_info->rd_kill = BITMAP_XMALLOC ();
417 bitmap_zero (bb_info->rd_kill);
418 bb_info->rd_gen = BITMAP_XMALLOC ();
419 bitmap_zero (bb_info->rd_gen);
420 bb_info->rd_in = BITMAP_XMALLOC ();
421 bb_info->rd_out = BITMAP_XMALLOC ();
422 bb_info->rd_valid = 0;
425 if (flags & DF_RU && ! bb_info->ru_in)
427 /* Allocate bitmaps for upward exposed uses. */
428 bb_info->ru_kill = BITMAP_XMALLOC ();
429 bitmap_zero (bb_info->ru_kill);
430 /* Note the lack of symmetry. */
431 bb_info->ru_gen = BITMAP_XMALLOC ();
432 bitmap_zero (bb_info->ru_gen);
433 bb_info->ru_in = BITMAP_XMALLOC ();
434 bb_info->ru_out = BITMAP_XMALLOC ();
435 bb_info->ru_valid = 0;
438 if (flags & DF_LR && ! bb_info->lr_in)
440 /* Allocate bitmaps for live variables. */
441 bb_info->lr_def = BITMAP_XMALLOC ();
442 bitmap_zero (bb_info->lr_def);
443 bb_info->lr_use = BITMAP_XMALLOC ();
444 bitmap_zero (bb_info->lr_use);
445 bb_info->lr_in = BITMAP_XMALLOC ();
446 bb_info->lr_out = BITMAP_XMALLOC ();
447 bb_info->lr_valid = 0;
453 /* Free bitmaps for each basic block. */
455 df_bitmaps_free (df, flags)
456 struct df *df ATTRIBUTE_UNUSED;
461 for (i = 0; i < df->n_bbs; i++)
463 basic_block bb = BASIC_BLOCK (i);
464 struct bb_info *bb_info = DF_BB_INFO (df, bb);
469 if ((flags & DF_RD) && bb_info->rd_in)
471 /* Free bitmaps for reaching definitions. */
472 BITMAP_XFREE (bb_info->rd_kill);
473 bb_info->rd_kill = NULL;
474 BITMAP_XFREE (bb_info->rd_gen);
475 bb_info->rd_gen = NULL;
476 BITMAP_XFREE (bb_info->rd_in);
477 bb_info->rd_in = NULL;
478 BITMAP_XFREE (bb_info->rd_out);
479 bb_info->rd_out = NULL;
482 if ((flags & DF_RU) && bb_info->ru_in)
484 /* Free bitmaps for upward exposed uses. */
485 BITMAP_XFREE (bb_info->ru_kill);
486 bb_info->ru_kill = NULL;
487 BITMAP_XFREE (bb_info->ru_gen);
488 bb_info->ru_gen = NULL;
489 BITMAP_XFREE (bb_info->ru_in);
490 bb_info->ru_in = NULL;
491 BITMAP_XFREE (bb_info->ru_out);
492 bb_info->ru_out = NULL;
495 if ((flags & DF_LR) && bb_info->lr_in)
497 /* Free bitmaps for live variables. */
498 BITMAP_XFREE (bb_info->lr_def);
499 bb_info->lr_def = NULL;
500 BITMAP_XFREE (bb_info->lr_use);
501 bb_info->lr_use = NULL;
502 BITMAP_XFREE (bb_info->lr_in);
503 bb_info->lr_in = NULL;
504 BITMAP_XFREE (bb_info->lr_out);
505 bb_info->lr_out = NULL;
508 df->flags &= ~(flags & (DF_RD | DF_RU | DF_LR));
512 /* Allocate and initialise dataflow memory. */
514 df_alloc (df, n_regs)
521 gcc_obstack_init (&df_ref_obstack);
523 /* Perhaps we should use LUIDs to save memory for the insn_refs
524 table. This is only a small saving; a few pointers. */
525 n_insns = get_max_uid () + 1;
529 /* Approximate number of defs by number of insns. */
530 df->def_size = n_insns;
531 df->defs = xmalloc (df->def_size * sizeof (*df->defs));
535 /* Approximate number of uses by twice number of insns. */
536 df->use_size = n_insns * 2;
537 df->uses = xmalloc (df->use_size * sizeof (*df->uses));
540 df->n_bbs = n_basic_blocks;
542 /* Allocate temporary working array used during local dataflow analysis. */
543 df->reg_def_last = xmalloc (df->n_regs * sizeof (struct ref *));
545 df_insn_table_realloc (df, n_insns);
547 df_reg_table_realloc (df, df->n_regs);
549 df->bbs_modified = BITMAP_XMALLOC ();
550 bitmap_zero (df->bbs_modified);
554 df->bbs = xcalloc (df->n_bbs, sizeof (struct bb_info));
556 df->all_blocks = BITMAP_XMALLOC ();
557 for (i = 0; i < n_basic_blocks; i++)
558 bitmap_set_bit (df->all_blocks, i);
562 /* Free all the dataflow info. */
567 df_bitmaps_free (df, DF_ALL);
595 if (df->bbs_modified)
596 BITMAP_XFREE (df->bbs_modified);
597 df->bbs_modified = 0;
599 if (df->insns_modified)
600 BITMAP_XFREE (df->insns_modified);
601 df->insns_modified = 0;
603 BITMAP_XFREE (df->all_blocks);
606 obstack_free (&df_ref_obstack, NULL);
609 /* Local miscellaneous routines. */
611 /* Return a USE for register REGNO. */
612 static rtx df_reg_use_gen (regno)
618 reg = regno >= FIRST_PSEUDO_REGISTER
619 ? regno_reg_rtx[regno] : gen_rtx_REG (reg_raw_mode[regno], regno);
621 use = gen_rtx_USE (GET_MODE (reg), reg);
626 /* Return a CLOBBER for register REGNO. */
627 static rtx df_reg_clobber_gen (regno)
633 reg = regno >= FIRST_PSEUDO_REGISTER
634 ? regno_reg_rtx[regno] : gen_rtx_REG (reg_raw_mode[regno], regno);
636 use = gen_rtx_CLOBBER (GET_MODE (reg), reg);
640 /* Local chain manipulation routines. */
642 /* Create a link in a def-use or use-def chain. */
643 static inline struct df_link *
644 df_link_create (ref, next)
646 struct df_link *next;
648 struct df_link *link;
650 link = (struct df_link *) obstack_alloc (&df_ref_obstack,
658 /* Add REF to chain head pointed to by PHEAD. */
659 static struct df_link *
660 df_ref_unlink (phead, ref)
661 struct df_link **phead;
664 struct df_link *link = *phead;
670 /* Only a single ref. It must be the one we want.
671 If not, the def-use and use-def chains are likely to
673 if (link->ref != ref)
675 /* Now have an empty chain. */
680 /* Multiple refs. One of them must be us. */
681 if (link->ref == ref)
686 for (; link->next; link = link->next)
688 if (link->next->ref == ref)
690 /* Unlink from list. */
691 link->next = link->next->next;
702 /* Unlink REF from all def-use/use-def chains, etc. */
704 df_ref_remove (df, ref)
708 if (DF_REF_REG_DEF_P (ref))
710 df_def_unlink (df, ref);
711 df_ref_unlink (&df->insns[DF_REF_INSN_UID (ref)].defs, ref);
715 df_use_unlink (df, ref);
716 df_ref_unlink (&df->insns[DF_REF_INSN_UID (ref)].uses, ref);
722 /* Unlink DEF from use-def and reg-def chains. */
724 df_def_unlink (df, def)
725 struct df *df ATTRIBUTE_UNUSED;
728 struct df_link *du_link;
729 unsigned int dregno = DF_REF_REGNO (def);
731 /* Follow def-use chain to find all the uses of this def. */
732 for (du_link = DF_REF_CHAIN (def); du_link; du_link = du_link->next)
734 struct ref *use = du_link->ref;
736 /* Unlink this def from the use-def chain. */
737 df_ref_unlink (&DF_REF_CHAIN (use), def);
739 DF_REF_CHAIN (def) = 0;
741 /* Unlink def from reg-def chain. */
742 df_ref_unlink (&df->regs[dregno].defs, def);
744 df->defs[DF_REF_ID (def)] = 0;
748 /* Unlink use from def-use and reg-use chains. */
750 df_use_unlink (df, use)
751 struct df *df ATTRIBUTE_UNUSED;
754 struct df_link *ud_link;
755 unsigned int uregno = DF_REF_REGNO (use);
757 /* Follow use-def chain to find all the defs of this use. */
758 for (ud_link = DF_REF_CHAIN (use); ud_link; ud_link = ud_link->next)
760 struct ref *def = ud_link->ref;
762 /* Unlink this use from the def-use chain. */
763 df_ref_unlink (&DF_REF_CHAIN (def), use);
765 DF_REF_CHAIN (use) = 0;
767 /* Unlink use from reg-use chain. */
768 df_ref_unlink (&df->regs[uregno].uses, use);
770 df->uses[DF_REF_ID (use)] = 0;
773 /* Local routines for recording refs. */
776 /* Create a new ref of type DF_REF_TYPE for register REG at address
777 LOC within INSN of BB. */
779 df_ref_create (df, reg, loc, bb, insn, ref_type)
785 enum df_ref_type ref_type;
787 struct ref *this_ref;
790 this_ref = (struct ref *) obstack_alloc (&df_ref_obstack,
792 DF_REF_REG (this_ref) = reg;
793 DF_REF_LOC (this_ref) = loc;
794 DF_REF_BB (this_ref) = bb;
795 DF_REF_INSN (this_ref) = insn;
796 DF_REF_CHAIN (this_ref) = 0;
797 DF_REF_TYPE (this_ref) = ref_type;
798 uid = INSN_UID (insn);
800 if (ref_type == DF_REF_REG_DEF)
802 if (df->def_id >= df->def_size)
804 /* Make table 25 percent larger. */
805 df->def_size += (df->def_size / 4);
806 df->defs = xrealloc (df->defs,
807 df->def_size * sizeof (*df->defs));
809 DF_REF_ID (this_ref) = df->def_id;
810 df->defs[df->def_id++] = this_ref;
814 if (df->use_id >= df->use_size)
816 /* Make table 25 percent larger. */
817 df->use_size += (df->use_size / 4);
818 df->uses = xrealloc (df->uses,
819 df->use_size * sizeof (*df->uses));
821 DF_REF_ID (this_ref) = df->use_id;
822 df->uses[df->use_id++] = this_ref;
828 /* Create a new reference of type DF_REF_TYPE for a single register REG,
829 used inside the LOC rtx of INSN. */
831 df_ref_record_1 (df, reg, loc, bb, insn, ref_type)
837 enum df_ref_type ref_type;
839 df_ref_create (df, reg, loc, bb, insn, ref_type);
843 /* Create new references of type DF_REF_TYPE for each part of register REG
844 at address LOC within INSN of BB. */
846 df_ref_record (df, reg, loc, bb, insn, ref_type)
852 enum df_ref_type ref_type;
856 if (GET_CODE (reg) != REG && GET_CODE (reg) != SUBREG)
859 /* For the reg allocator we are interested in some SUBREG rtx's, but not
860 all. Notably only those representing a word extraction from a multi-word
861 reg. As written in the docu those should have the form
862 (subreg:SI (reg:M A) N), with size(SImode) > size(Mmode).
863 XXX Is that true? We could also use the global word_mode variable. */
864 if (GET_CODE (reg) == SUBREG
865 && (GET_MODE_SIZE (GET_MODE (reg)) < GET_MODE_SIZE (word_mode)
866 || GET_MODE_SIZE (GET_MODE (reg))
867 >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (reg)))))
869 loc = &SUBREG_REG (reg);
873 regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
874 if (regno < FIRST_PSEUDO_REGISTER)
879 if (! (df->flags & DF_HARD_REGS))
882 /* GET_MODE (reg) is correct here. We don't want to go into a SUBREG
883 for the mode, because we only want to add references to regs, which
884 are really referenced. E.g. a (subreg:SI (reg:DI 0) 0) does _not_
885 reference the whole reg 0 in DI mode (which would also include
886 reg 1, at least, if 0 and 1 are SImode registers). */
887 endregno = regno + HARD_REGNO_NREGS (regno, GET_MODE (reg));
889 for (i = regno; i < endregno; i++)
890 df_ref_record_1 (df, gen_rtx_REG (reg_raw_mode[i], i),
891 loc, bb, insn, ref_type);
895 df_ref_record_1 (df, reg, loc, bb, insn, ref_type);
900 /* Process all the registers defined in the rtx, X. */
902 df_def_record_1 (df, x, bb, insn)
908 rtx *loc = &SET_DEST (x);
911 /* Some targets place small structures in registers for
912 return values of functions. */
913 if (GET_CODE (dst) == PARALLEL && GET_MODE (dst) == BLKmode)
917 for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
918 df_def_record_1 (df, XVECEXP (dst, 0, i), bb, insn);
922 /* May be, we should flag the use of strict_low_part somehow. Might be
923 handy for the reg allocator. */
925 while (GET_CODE (dst) == STRICT_LOW_PART
926 || GET_CODE (dst) == ZERO_EXTRACT
927 || GET_CODE (dst) == SIGN_EXTRACT)
929 loc = &XEXP (dst, 0);
932 /* For the reg allocator we are interested in exact register references.
933 This means, we want to know, if only a part of a register is
936 if (GET_CODE (dst) == SUBREG)
938 loc = &XEXP (dst, 0);
943 while (GET_CODE (dst) == SUBREG
944 || GET_CODE (dst) == ZERO_EXTRACT
945 || GET_CODE (dst) == SIGN_EXTRACT
946 || GET_CODE (dst) == STRICT_LOW_PART)
948 loc = &XEXP (dst, 0);
953 if (GET_CODE (dst) == REG
954 || (GET_CODE (dst) == SUBREG && GET_CODE (SUBREG_REG (dst)) == REG))
955 df_ref_record (df, dst, loc, bb, insn, DF_REF_REG_DEF);
959 /* Process all the registers defined in the pattern rtx, X. */
961 df_defs_record (df, x, bb, insn)
967 RTX_CODE code = GET_CODE (x);
969 if (code == SET || code == CLOBBER)
971 /* Mark the single def within the pattern. */
972 df_def_record_1 (df, x, bb, insn);
974 else if (code == PARALLEL)
978 /* Mark the multiple defs within the pattern. */
979 for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
981 code = GET_CODE (XVECEXP (x, 0, i));
982 if (code == SET || code == CLOBBER)
983 df_def_record_1 (df, XVECEXP (x, 0, i), bb, insn);
989 /* Process all the registers used in the rtx at address LOC. */
991 df_uses_record (df, loc, ref_type, bb, insn)
994 enum df_ref_type ref_type;
1003 code = GET_CODE (x);
1017 /* If we are clobbering a MEM, mark any registers inside the address
1019 if (GET_CODE (XEXP (x, 0)) == MEM)
1020 df_uses_record (df, &XEXP (XEXP (x, 0), 0),
1021 DF_REF_REG_MEM_STORE, bb, insn);
1023 /* If we're clobbering a REG then we have a def so ignore. */
1027 df_uses_record (df, &XEXP (x, 0), DF_REF_REG_MEM_LOAD, bb, insn);
1031 /* While we're here, optimize this case. */
1032 #if defined(HANDLE_SUBREG)
1034 /* In case the SUBREG is not of a register, don't optimize. */
1035 if (GET_CODE (SUBREG_REG (x)) != REG)
1037 loc = &SUBREG_REG (x);
1038 df_uses_record (df, loc, ref_type, bb, insn);
1042 loc = &SUBREG_REG (x);
1044 if (GET_CODE (x) != REG)
1046 df_uses_record (df, loc, ref_type, bb, insn);
1051 /* ... Fall through ... */
1054 /* See a register (or subreg) other than being set. */
1055 df_ref_record (df, x, loc, bb, insn, ref_type);
1060 rtx dst = SET_DEST (x);
1063 /* If storing into MEM, don't show it as being used. But do
1064 show the address as being used. */
1065 if (GET_CODE (dst) == MEM)
1067 df_uses_record (df, &XEXP (dst, 0),
1068 DF_REF_REG_MEM_STORE,
1070 df_uses_record (df, &SET_SRC (x), DF_REF_REG_USE, bb, insn);
1074 #if 1 && defined(HANDLE_SUBREG)
1075 /* Look for sets that perform a read-modify-write. */
1076 while (GET_CODE (dst) == STRICT_LOW_PART
1077 || GET_CODE (dst) == ZERO_EXTRACT
1078 || GET_CODE (dst) == SIGN_EXTRACT)
1080 if (GET_CODE (dst) == STRICT_LOW_PART)
1082 dst = XEXP (dst, 0);
1083 if (GET_CODE (dst) != SUBREG)
1085 /* A strict_low_part uses the whole reg not only the subreg. */
1086 df_uses_record (df, &SUBREG_REG (dst), DF_REF_REG_USE, bb, insn);
1090 df_uses_record (df, &XEXP (dst, 0), DF_REF_REG_USE, bb, insn);
1091 dst = XEXP (dst, 0);
1094 if (GET_CODE (dst) == SUBREG)
1096 /* Paradoxical or too small subreg's are read-mod-write. */
1097 if (GET_MODE_SIZE (GET_MODE (dst)) < GET_MODE_SIZE (word_mode)
1098 || GET_MODE_SIZE (GET_MODE (dst))
1099 >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dst))))
1102 /* In the original code also some SUBREG rtx's were considered
1103 read-modify-write (those with
1104 REG_SIZE(SUBREG_REG(dst)) > REG_SIZE(dst) )
1105 e.g. a (subreg:QI (reg:SI A) 0). I can't see this. The only
1106 reason for a read cycle for reg A would be to somehow preserve
1107 the bits outside of the subreg:QI. But for this a strict_low_part
1108 was necessary anyway, and this we handled already. */
1110 while (GET_CODE (dst) == STRICT_LOW_PART
1111 || GET_CODE (dst) == ZERO_EXTRACT
1112 || GET_CODE (dst) == SIGN_EXTRACT
1113 || GET_CODE (dst) == SUBREG)
1115 /* A SUBREG of a smaller size does not use the old value. */
1116 if (GET_CODE (dst) != SUBREG
1117 || (REG_SIZE (SUBREG_REG (dst)) > REG_SIZE (dst)))
1119 dst = XEXP (dst, 0);
1123 if ((GET_CODE (dst) == PARALLEL && GET_MODE (dst) == BLKmode)
1124 || GET_CODE (dst) == REG || GET_CODE (dst) == SUBREG)
1126 #if 1 || !defined(HANDLE_SUBREG)
1128 df_uses_record (df, &SET_DEST (x), DF_REF_REG_USE, bb, insn);
1130 df_uses_record (df, &SET_SRC (x), DF_REF_REG_USE, bb, insn);
1140 case UNSPEC_VOLATILE:
1144 /* Traditional and volatile asm instructions must be considered to use
1145 and clobber all hard registers, all pseudo-registers and all of
1146 memory. So must TRAP_IF and UNSPEC_VOLATILE operations.
1148 Consider for instance a volatile asm that changes the fpu rounding
1149 mode. An insn should not be moved across this even if it only uses
1150 pseudo-regs because it might give an incorrectly rounded result.
1152 For now, just mark any regs we can find in ASM_OPERANDS as
1155 /* For all ASM_OPERANDS, we must traverse the vector of input operands.
1156 We can not just fall through here since then we would be confused
1157 by the ASM_INPUT rtx inside ASM_OPERANDS, which do not indicate
1158 traditional asms unlike their normal usage. */
1159 if (code == ASM_OPERANDS)
1163 for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++)
1164 df_uses_record (df, &ASM_OPERANDS_INPUT (x, j),
1165 DF_REF_REG_USE, bb, insn);
1177 /* Catch the def of the register being modified. */
1178 df_ref_record (df, XEXP (x, 0), &XEXP (x, 0), bb, insn, DF_REF_REG_DEF);
1180 /* ... Fall through to handle uses ... */
1186 /* Recursively scan the operands of this expression. */
1188 register const char *fmt = GET_RTX_FORMAT (code);
1191 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1195 /* Tail recursive case: save a function call level. */
1201 df_uses_record (df, &XEXP (x, i), ref_type, bb, insn);
1203 else if (fmt[i] == 'E')
1206 for (j = 0; j < XVECLEN (x, i); j++)
1207 df_uses_record (df, &XVECEXP (x, i, j), ref_type,
1215 /* Record all the df within INSN of basic block BB. */
1217 df_insn_refs_record (df, bb, insn)
1226 /* Record register defs */
1227 df_defs_record (df, PATTERN (insn), bb, insn);
1229 if (GET_CODE (insn) == CALL_INSN)
1234 /* Record the registers used to pass arguments. */
1235 for (note = CALL_INSN_FUNCTION_USAGE (insn); note;
1236 note = XEXP (note, 1))
1238 if (GET_CODE (XEXP (note, 0)) == USE)
1239 df_uses_record (df, &SET_DEST (XEXP (note, 0)), DF_REF_REG_USE,
1243 /* The stack ptr is used (honorarily) by a CALL insn. */
1244 x = df_reg_use_gen (STACK_POINTER_REGNUM);
1245 df_uses_record (df, &SET_DEST (x), DF_REF_REG_USE, bb, insn);
1247 if (df->flags & DF_HARD_REGS)
1249 /* Calls may also reference any of the global registers,
1250 so they are recorded as used. */
1251 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1254 x = df_reg_use_gen (i);
1255 df_uses_record (df, &SET_DEST (x),
1256 DF_REF_REG_USE, bb, insn);
1261 /* Record the register uses. */
1262 df_uses_record (df, &PATTERN (insn),
1263 DF_REF_REG_USE, bb, insn);
1266 if (GET_CODE (insn) == CALL_INSN)
1270 if (df->flags & DF_HARD_REGS)
1272 /* Kill all registers invalidated by a call. */
1273 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1274 if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
1276 rtx reg_clob = df_reg_clobber_gen (i);
1277 df_defs_record (df, reg_clob, bb, insn);
1281 /* There may be extra registers to be clobbered. */
1282 for (note = CALL_INSN_FUNCTION_USAGE (insn);
1284 note = XEXP (note, 1))
1285 if (GET_CODE (XEXP (note, 0)) == CLOBBER)
1286 df_defs_record (df, XEXP (note, 0), bb, insn);
1292 /* Record all the refs within the basic block BB. */
1294 df_bb_refs_record (df, bb)
1300 /* Scan the block an insn at a time from beginning to end. */
1301 for (insn = bb->head; ; insn = NEXT_INSN (insn))
1305 /* Record defs within INSN. */
1306 df_insn_refs_record (df, bb, insn);
1308 if (insn == bb->end)
1314 /* Record all the refs in the basic blocks specified by BLOCKS. */
1316 df_refs_record (df, blocks)
1322 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
1324 df_bb_refs_record (df, bb);
1328 /* Dataflow analysis routines. */
1331 /* Create reg-def chains for basic block BB. These are a list of
1332 definitions for each register. */
1334 df_bb_reg_def_chain_create (df, bb)
1340 /* Perhaps the defs should be sorted using a depth first search
1341 of the CFG (or possibly a breadth first search). We currently
1342 scan the basic blocks in reverse order so that the first defs
1343 apprear at the start of the chain. */
1345 for (insn = bb->end; insn && insn != PREV_INSN (bb->head);
1346 insn = PREV_INSN (insn))
1348 struct df_link *link;
1349 unsigned int uid = INSN_UID (insn);
1351 if (! INSN_P (insn))
1354 for (link = df->insns[uid].defs; link; link = link->next)
1356 struct ref *def = link->ref;
1357 unsigned int dregno = DF_REF_REGNO (def);
1359 df->regs[dregno].defs
1360 = df_link_create (def, df->regs[dregno].defs);
1366 /* Create reg-def chains for each basic block within BLOCKS. These
1367 are a list of definitions for each register. */
1369 df_reg_def_chain_create (df, blocks)
1375 FOR_EACH_BB_IN_BITMAP/*_REV*/ (blocks, 0, bb,
1377 df_bb_reg_def_chain_create (df, bb);
1382 /* Create reg-use chains for basic block BB. These are a list of uses
1383 for each register. */
1385 df_bb_reg_use_chain_create (df, bb)
1391 /* Scan in forward order so that the last uses appear at the
1392 start of the chain. */
1394 for (insn = bb->head; insn && insn != NEXT_INSN (bb->end);
1395 insn = NEXT_INSN (insn))
1397 struct df_link *link;
1398 unsigned int uid = INSN_UID (insn);
1400 if (! INSN_P (insn))
1403 for (link = df->insns[uid].uses; link; link = link->next)
1405 struct ref *use = link->ref;
1406 unsigned int uregno = DF_REF_REGNO (use);
1408 df->regs[uregno].uses
1409 = df_link_create (use, df->regs[uregno].uses);
1415 /* Create reg-use chains for each basic block within BLOCKS. These
1416 are a list of uses for each register. */
1418 df_reg_use_chain_create (df, blocks)
1424 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
1426 df_bb_reg_use_chain_create (df, bb);
1431 /* Create def-use chains from reaching use bitmaps for basic block BB. */
1433 df_bb_du_chain_create (df, bb, ru)
1438 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1441 bitmap_copy (ru, bb_info->ru_out);
1443 /* For each def in BB create a linked list (chain) of uses
1444 reached from the def. */
1445 for (insn = bb->end; insn && insn != PREV_INSN (bb->head);
1446 insn = PREV_INSN (insn))
1448 struct df_link *def_link;
1449 struct df_link *use_link;
1450 unsigned int uid = INSN_UID (insn);
1452 if (! INSN_P (insn))
1455 /* For each def in insn... */
1456 for (def_link = df->insns[uid].defs; def_link; def_link = def_link->next)
1458 struct ref *def = def_link->ref;
1459 unsigned int dregno = DF_REF_REGNO (def);
1461 DF_REF_CHAIN (def) = 0;
1463 /* While the reg-use chains are not essential, it
1464 is _much_ faster to search these short lists rather
1465 than all the reaching uses, especially for large functions. */
1466 for (use_link = df->regs[dregno].uses; use_link;
1467 use_link = use_link->next)
1469 struct ref *use = use_link->ref;
1471 if (bitmap_bit_p (ru, DF_REF_ID (use)))
1474 = df_link_create (use, DF_REF_CHAIN (def));
1476 bitmap_clear_bit (ru, DF_REF_ID (use));
1481 /* For each use in insn... */
1482 for (use_link = df->insns[uid].uses; use_link; use_link = use_link->next)
1484 struct ref *use = use_link->ref;
1485 bitmap_set_bit (ru, DF_REF_ID (use));
1491 /* Create def-use chains from reaching use bitmaps for basic blocks
1494 df_du_chain_create (df, blocks)
1501 ru = BITMAP_XMALLOC ();
1503 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
1505 df_bb_du_chain_create (df, bb, ru);
1512 /* Create use-def chains from reaching def bitmaps for basic block BB. */
1514 df_bb_ud_chain_create (df, bb)
1518 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1519 struct ref **reg_def_last = df->reg_def_last;
1522 memset (reg_def_last, 0, df->n_regs * sizeof (struct ref *));
1524 /* For each use in BB create a linked list (chain) of defs
1525 that reach the use. */
1526 for (insn = bb->head; insn && insn != NEXT_INSN (bb->end);
1527 insn = NEXT_INSN (insn))
1529 unsigned int uid = INSN_UID (insn);
1530 struct df_link *use_link;
1531 struct df_link *def_link;
1533 if (! INSN_P (insn))
1536 /* For each use in insn... */
1537 for (use_link = df->insns[uid].uses; use_link; use_link = use_link->next)
1539 struct ref *use = use_link->ref;
1540 unsigned int regno = DF_REF_REGNO (use);
1542 DF_REF_CHAIN (use) = 0;
1544 /* Has regno been defined in this BB yet? If so, use
1545 the last def as the single entry for the use-def
1546 chain for this use. Otherwise, we need to add all
1547 the defs using this regno that reach the start of
1549 if (reg_def_last[regno])
1552 = df_link_create (reg_def_last[regno], 0);
1556 /* While the reg-def chains are not essential, it is
1557 _much_ faster to search these short lists rather than
1558 all the reaching defs, especially for large
1560 for (def_link = df->regs[regno].defs; def_link;
1561 def_link = def_link->next)
1563 struct ref *def = def_link->ref;
1565 if (bitmap_bit_p (bb_info->rd_in, DF_REF_ID (def)))
1568 = df_link_create (def, DF_REF_CHAIN (use));
1575 /* For each def in insn...record the last def of each reg. */
1576 for (def_link = df->insns[uid].defs; def_link; def_link = def_link->next)
1578 struct ref *def = def_link->ref;
1579 int dregno = DF_REF_REGNO (def);
1581 reg_def_last[dregno] = def;
1587 /* Create use-def chains from reaching def bitmaps for basic blocks
1590 df_ud_chain_create (df, blocks)
1596 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
1598 df_bb_ud_chain_create (df, bb);
1603 /* Use depth first order, and the worklist, to figure out what block
1607 df_visit_next (df, blocks)
1608 struct df *df ATTRIBUTE_UNUSED;
1612 for (i = 0; i < n_basic_blocks; i++)
1613 if (TEST_BIT (blocks, df->rc_order[i]))
1614 return df->rc_order[i];
1615 return sbitmap_first_set_bit (blocks);
1618 /* Calculate reaching defs for each basic block in BLOCKS, i.e., the
1619 defs that are live at the start of a basic block. */
1621 df_rd_global_compute (df, blocks)
1622 struct df *df ATTRIBUTE_UNUSED;
1629 worklist = sbitmap_alloc (n_basic_blocks);
1630 sbitmap_zero (worklist);
1632 /* Copy the blocklist to the worklist */
1633 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i,
1635 SET_BIT (worklist, i);
1638 /* We assume that only the basic blocks in WORKLIST have been
1640 FOR_EACH_BB_IN_SBITMAP (worklist, 0, bb,
1642 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1644 bitmap_copy (bb_info->rd_out, bb_info->rd_gen);
1647 while ((i = df_visit_next (df, worklist)) >= 0)
1649 struct bb_info *bb_info;
1653 /* Remove this block from the worklist. */
1654 RESET_BIT (worklist, i);
1657 bb = BASIC_BLOCK (i);
1658 bb_info = DF_BB_INFO (df, bb);
1660 /* Calculate union of predecessor outs. */
1661 bitmap_zero (bb_info->rd_in);
1662 for (e = bb->pred; e != 0; e = e->pred_next)
1664 struct bb_info *pred_refs = DF_BB_INFO (df, e->src);
1666 if (e->src == ENTRY_BLOCK_PTR)
1669 bitmap_a_or_b (bb_info->rd_in, bb_info->rd_in,
1673 /* RD_OUT is the set of defs that are live at the end of the
1674 BB. These are the defs that are either generated by defs
1675 (RD_GEN) within the BB or are live at the start (RD_IN)
1676 and are not killed by other defs (RD_KILL). */
1677 changed = bitmap_union_of_diff (bb_info->rd_out, bb_info->rd_gen,
1678 bb_info->rd_in, bb_info->rd_kill);
1682 /* Add each of this block's successors to the worklist. */
1683 for (e = bb->succ; e != 0; e = e->succ_next)
1685 if (e->dest == EXIT_BLOCK_PTR)
1688 SET_BIT (worklist, e->dest->index);
1692 sbitmap_free (worklist);
1696 /* Calculate reaching uses for each basic block within BLOCKS, i.e.,
1697 the uses that are live at the start of a basic block. */
1699 df_ru_global_compute (df, blocks)
1700 struct df *df ATTRIBUTE_UNUSED;
1707 worklist = sbitmap_alloc (n_basic_blocks);
1708 sbitmap_zero (worklist);
1710 EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i,
1712 SET_BIT (worklist, i);
1715 /* We assume that only the basic blocks in WORKLIST have been
1717 FOR_EACH_BB_IN_SBITMAP (worklist, 0, bb,
1719 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1721 bitmap_copy (bb_info->ru_in, bb_info->ru_gen);
1725 while ((i = df_visit_next (df, worklist)) >= 0)
1727 struct bb_info *bb_info;
1731 /* Remove this block from the worklist. */
1732 RESET_BIT (worklist, i);
1734 bb = BASIC_BLOCK (i);
1735 bb_info = DF_BB_INFO (df, bb);
1737 /* Calculate union of successor ins. */
1738 bitmap_zero (bb_info->ru_out);
1739 for (e = bb->succ; e != 0; e = e->succ_next)
1741 struct bb_info *succ_refs = DF_BB_INFO (df, e->dest);
1743 if (e->dest == EXIT_BLOCK_PTR)
1746 bitmap_a_or_b (bb_info->ru_out, bb_info->ru_out,
1750 /* RU_IN is the set of uses that are live at the start of the
1751 BB. These are the uses that are either generated within the
1752 BB (RU_GEN) or are live at the end (RU_OUT) and are not uses
1753 killed by defs within the BB (RU_KILL). */
1754 changed = bitmap_union_of_diff (bb_info->ru_in, bb_info->ru_gen,
1755 bb_info->ru_out, bb_info->ru_kill);
1759 /* Add each of this block's predecessors to the worklist. */
1760 for (e = bb->pred; e != 0; e = e->pred_next)
1762 if (e->src == ENTRY_BLOCK_PTR)
1765 SET_BIT (worklist, e->src->index);
1770 sbitmap_free (worklist);
1774 /* Calculate live registers for each basic block within BLOCKS. */
1776 df_lr_global_compute (df, blocks)
1777 struct df *df ATTRIBUTE_UNUSED;
1784 worklist = BITMAP_XMALLOC ();
1785 bitmap_copy (worklist, blocks);
1787 /* We assume that only the basic blocks in WORKLIST have been
1789 FOR_EACH_BB_IN_BITMAP (worklist, 0, bb,
1791 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1793 bitmap_copy (bb_info->lr_in, bb_info->lr_use);
1796 while ((i = bitmap_last_set_bit (worklist)) >= 0)
1798 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1802 /* Remove this block from the worklist. */
1803 bitmap_clear_bit (worklist, i);
1805 bb = BASIC_BLOCK (i);
1806 bb_info = DF_BB_INFO (df, bb);
1808 /* Calculate union of successor ins. */
1809 bitmap_zero (bb_info->lr_out);
1810 for (e = bb->succ; e != 0; e = e->succ_next)
1812 struct bb_info *succ_refs = DF_BB_INFO (df, e->dest);
1814 if (e->dest == EXIT_BLOCK_PTR)
1817 bitmap_a_or_b (bb_info->lr_out, bb_info->lr_out,
1821 /* LR_IN is the set of uses that are live at the start of the
1822 BB. These are the uses that are either generated by uses
1823 (LR_USE) within the BB or are live at the end (LR_OUT)
1824 and are not killed by other uses (LR_DEF). */
1825 changed = bitmap_union_of_diff (bb_info->lr_in, bb_info->lr_use,
1826 bb_info->lr_out, bb_info->lr_def);
1830 /* Add each of this block's predecessors to the worklist. */
1831 for (e = bb->pred; e != 0; e = e->pred_next)
1833 if (e->src == ENTRY_BLOCK_PTR)
1836 bitmap_set_bit (worklist, e->src->index);
1840 BITMAP_XFREE (worklist);
1844 /* Compute local reaching def info for basic block BB. */
1846 df_bb_rd_local_compute (df, bb)
1850 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1853 for (insn = bb->head; insn && insn != NEXT_INSN (bb->end);
1854 insn = NEXT_INSN (insn))
1856 unsigned int uid = INSN_UID (insn);
1857 struct df_link *def_link;
1859 if (! INSN_P (insn))
1862 for (def_link = df->insns[uid].defs; def_link; def_link = def_link->next)
1864 struct ref *def = def_link->ref;
1865 unsigned int regno = DF_REF_REGNO (def);
1866 struct df_link *def2_link;
1868 for (def2_link = df->regs[regno].defs; def2_link;
1869 def2_link = def2_link->next)
1871 struct ref *def2 = def2_link->ref;
1873 /* Add all defs of this reg to the set of kills. This
1874 is greedy since many of these defs will not actually
1875 be killed by this BB but it keeps things a lot
1877 bitmap_set_bit (bb_info->rd_kill, DF_REF_ID (def2));
1879 /* Zap from the set of gens for this BB. */
1880 bitmap_clear_bit (bb_info->rd_gen, DF_REF_ID (def2));
1883 bitmap_set_bit (bb_info->rd_gen, DF_REF_ID (def));
1887 bb_info->rd_valid = 1;
1891 /* Compute local reaching def info for each basic block within BLOCKS. */
1893 df_rd_local_compute (df, blocks)
1899 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
1901 df_bb_rd_local_compute (df, bb);
1906 /* Compute local reaching use (upward exposed use) info for basic
1909 df_bb_ru_local_compute (df, bb)
1913 /* This is much more tricky than computing reaching defs. With
1914 reaching defs, defs get killed by other defs. With upwards
1915 exposed uses, these get killed by defs with the same regno. */
1917 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1920 for (insn = bb->end; insn && insn != PREV_INSN (bb->head);
1921 insn = PREV_INSN (insn))
1923 unsigned int uid = INSN_UID (insn);
1924 struct df_link *def_link;
1925 struct df_link *use_link;
1927 if (! INSN_P (insn))
1930 for (def_link = df->insns[uid].defs; def_link; def_link = def_link->next)
1932 struct ref *def = def_link->ref;
1933 unsigned int dregno = DF_REF_REGNO (def);
1935 for (use_link = df->regs[dregno].uses; use_link;
1936 use_link = use_link->next)
1938 struct ref *use = use_link->ref;
1940 /* Add all uses of this reg to the set of kills. This
1941 is greedy since many of these uses will not actually
1942 be killed by this BB but it keeps things a lot
1944 bitmap_set_bit (bb_info->ru_kill, DF_REF_ID (use));
1946 /* Zap from the set of gens for this BB. */
1947 bitmap_clear_bit (bb_info->ru_gen, DF_REF_ID (use));
1951 for (use_link = df->insns[uid].uses; use_link; use_link = use_link->next)
1953 struct ref *use = use_link->ref;
1954 /* Add use to set of gens in this BB. */
1955 bitmap_set_bit (bb_info->ru_gen, DF_REF_ID (use));
1958 bb_info->ru_valid = 1;
1962 /* Compute local reaching use (upward exposed use) info for each basic
1963 block within BLOCKS. */
1965 df_ru_local_compute (df, blocks)
1971 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
1973 df_bb_ru_local_compute (df, bb);
1978 /* Compute local live variable info for basic block BB. */
1980 df_bb_lr_local_compute (df, bb)
1984 struct bb_info *bb_info = DF_BB_INFO (df, bb);
1987 for (insn = bb->end; insn && insn != PREV_INSN (bb->head);
1988 insn = PREV_INSN (insn))
1990 unsigned int uid = INSN_UID (insn);
1991 struct df_link *link;
1993 if (! INSN_P (insn))
1996 for (link = df->insns[uid].defs; link; link = link->next)
1998 struct ref *def = link->ref;
1999 unsigned int dregno = DF_REF_REGNO (def);
2001 /* Add def to set of defs in this BB. */
2002 bitmap_set_bit (bb_info->lr_def, dregno);
2004 bitmap_clear_bit (bb_info->lr_use, dregno);
2007 for (link = df->insns[uid].uses; link; link = link->next)
2009 struct ref *use = link->ref;
2010 /* Add use to set of uses in this BB. */
2011 bitmap_set_bit (bb_info->lr_use, DF_REF_REGNO (use));
2014 bb_info->lr_valid = 1;
2018 /* Compute local live variable info for each basic block within BLOCKS. */
2020 df_lr_local_compute (df, blocks)
2026 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
2028 df_bb_lr_local_compute (df, bb);
2033 /* Compute register info: lifetime, bb, and number of defs and uses
2034 for basic block BB. */
2036 df_bb_reg_info_compute (df, bb, live)
2041 struct reg_info *reg_info = df->regs;
2042 struct bb_info *bb_info = DF_BB_INFO (df, bb);
2045 bitmap_copy (live, bb_info->lr_out);
2047 for (insn = bb->end; insn && insn != PREV_INSN (bb->head);
2048 insn = PREV_INSN (insn))
2050 unsigned int uid = INSN_UID (insn);
2052 struct df_link *link;
2054 if (! INSN_P (insn))
2057 for (link = df->insns[uid].defs; link; link = link->next)
2059 struct ref *def = link->ref;
2060 unsigned int dregno = DF_REF_REGNO (def);
2062 /* Kill this register. */
2063 bitmap_clear_bit (live, dregno);
2064 reg_info[dregno].n_defs++;
2067 for (link = df->insns[uid].uses; link; link = link->next)
2069 struct ref *use = link->ref;
2070 unsigned int uregno = DF_REF_REGNO (use);
2072 /* This register is now live. */
2073 bitmap_set_bit (live, uregno);
2074 reg_info[uregno].n_uses++;
2077 /* Increment lifetimes of all live registers. */
2078 EXECUTE_IF_SET_IN_BITMAP (live, 0, regno,
2080 reg_info[regno].lifetime++;
2086 /* Compute register info: lifetime, bb, and number of defs and uses. */
2088 df_reg_info_compute (df, blocks)
2095 live = BITMAP_XMALLOC ();
2097 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
2099 df_bb_reg_info_compute (df, bb, live);
2102 BITMAP_XFREE (live);
2106 /* Assign LUIDs for BB. */
2108 df_bb_luids_set (df, bb)
2115 /* The LUIDs are monotonically increasing for each basic block. */
2117 for (insn = bb->head; ; insn = NEXT_INSN (insn))
2120 DF_INSN_LUID (df, insn) = luid++;
2121 DF_INSN_LUID (df, insn) = luid;
2123 if (insn == bb->end)
2130 /* Assign LUIDs for each basic block within BLOCKS. */
2132 df_luids_set (df, blocks)
2139 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
2141 total += df_bb_luids_set (df, bb);
2147 /* Perform dataflow analysis using existing DF structure for blocks
2148 within BLOCKS. If BLOCKS is zero, use all basic blocks in the CFG. */
2150 df_analyse_1 (df, blocks, flags, update)
2161 if (flags & DF_UD_CHAIN)
2162 aflags |= DF_RD | DF_RD_CHAIN;
2164 if (flags & DF_DU_CHAIN)
2168 aflags |= DF_RU_CHAIN;
2170 if (flags & DF_REG_INFO)
2174 blocks = df->all_blocks;
2179 df_refs_update (df);
2180 /* More fine grained incremental dataflow analysis would be
2181 nice. For now recompute the whole shebang for the
2184 df_refs_unlink (df, blocks);
2186 /* All the def-use, use-def chains can be potentially
2187 modified by changes in one block. The size of the
2188 bitmaps can also change. */
2192 /* Scan the function for all register defs and uses. */
2194 df_refs_record (df, blocks);
2196 /* Link all the new defs and uses to the insns. */
2197 df_refs_process (df);
2200 /* Allocate the bitmaps now the total number of defs and uses are
2201 known. If the number of defs or uses have changed, then
2202 these bitmaps need to be reallocated. */
2203 df_bitmaps_alloc (df, aflags);
2205 /* Set the LUIDs for each specified basic block. */
2206 df_luids_set (df, blocks);
2208 /* Recreate reg-def and reg-use chains from scratch so that first
2209 def is at the head of the reg-def chain and the last use is at
2210 the head of the reg-use chain. This is only important for
2211 regs local to a basic block as it speeds up searching. */
2212 if (aflags & DF_RD_CHAIN)
2214 df_reg_def_chain_create (df, blocks);
2217 if (aflags & DF_RU_CHAIN)
2219 df_reg_use_chain_create (df, blocks);
2222 df->dfs_order = xmalloc (sizeof(int) * n_basic_blocks);
2223 df->rc_order = xmalloc (sizeof(int) * n_basic_blocks);
2225 flow_depth_first_order_compute (df->dfs_order, df->rc_order);
2229 /* Compute the sets of gens and kills for the defs of each bb. */
2230 df_rd_local_compute (df, df->flags & DF_RD ? blocks : df->all_blocks);
2232 /* Compute the global reaching definitions. */
2233 df_rd_global_compute (df, df->all_blocks);
2236 if (aflags & DF_UD_CHAIN)
2238 /* Create use-def chains. */
2239 df_ud_chain_create (df, df->all_blocks);
2241 if (! (flags & DF_RD))
2247 /* Compute the sets of gens and kills for the upwards exposed
2249 df_ru_local_compute (df, df->flags & DF_RU ? blocks : df->all_blocks);
2251 /* Compute the global reaching uses. */
2252 df_ru_global_compute (df, df->all_blocks);
2255 if (aflags & DF_DU_CHAIN)
2257 /* Create def-use chains. */
2258 df_du_chain_create (df, df->all_blocks);
2260 if (! (flags & DF_RU))
2264 /* Free up bitmaps that are no longer required. */
2266 df_bitmaps_free (df, dflags);
2270 /* Compute the sets of defs and uses of live variables. */
2271 df_lr_local_compute (df, df->flags & DF_LR ? blocks : df->all_blocks);
2273 /* Compute the global live variables. */
2274 df_lr_global_compute (df, df->all_blocks);
2277 if (aflags & DF_REG_INFO)
2279 df_reg_info_compute (df, df->all_blocks);
2281 free (df->dfs_order);
2282 free (df->rc_order);
2286 /* Initialise dataflow analysis. */
2292 df = xcalloc (1, sizeof (struct df));
2294 /* Squirrel away a global for debugging. */
2301 /* Start queuing refs. */
2306 df->def_id_save = df->def_id;
2307 df->use_id_save = df->use_id;
2308 /* ???? Perhaps we should save current obstack state so that we can
2314 /* Process queued refs. */
2316 df_refs_process (df)
2321 /* Build new insn-def chains. */
2322 for (i = df->def_id_save; i != df->def_id; i++)
2324 struct ref *def = df->defs[i];
2325 unsigned int uid = DF_REF_INSN_UID (def);
2327 /* Add def to head of def list for INSN. */
2329 = df_link_create (def, df->insns[uid].defs);
2332 /* Build new insn-use chains. */
2333 for (i = df->use_id_save; i != df->use_id; i++)
2335 struct ref *use = df->uses[i];
2336 unsigned int uid = DF_REF_INSN_UID (use);
2338 /* Add use to head of use list for INSN. */
2340 = df_link_create (use, df->insns[uid].uses);
2346 /* Update refs for basic block BB. */
2348 df_bb_refs_update (df, bb)
2355 /* While we have to scan the chain of insns for this BB, we don't
2356 need to allocate and queue a long chain of BB/INSN pairs. Using
2357 a bitmap for insns_modified saves memory and avoids queuing
2360 for (insn = bb->head; ; insn = NEXT_INSN (insn))
2364 uid = INSN_UID (insn);
2366 if (bitmap_bit_p (df->insns_modified, uid))
2368 /* Delete any allocated refs of this insn. MPH, FIXME. */
2369 df_insn_refs_unlink (df, bb, insn);
2371 /* Scan the insn for refs. */
2372 df_insn_refs_record (df, bb, insn);
2375 bitmap_clear_bit (df->insns_modified, uid);
2378 if (insn == bb->end)
2385 /* Process all the modified/deleted insns that were queued. */
2393 if ((unsigned int)max_reg_num () >= df->reg_size)
2394 df_reg_table_realloc (df, 0);
2398 FOR_EACH_BB_IN_BITMAP (df->bbs_modified, 0, bb,
2400 count += df_bb_refs_update (df, bb);
2403 df_refs_process (df);
2408 /* Return non-zero if any of the requested blocks in the bitmap
2409 BLOCKS have been modified. */
2411 df_modified_p (df, blocks)
2418 for (j = 0; j < df->n_bbs; j++)
2419 if (bitmap_bit_p (df->bbs_modified, j)
2420 && (! blocks || (blocks == (bitmap) -1) || bitmap_bit_p (blocks, j)))
2430 /* Analyse dataflow info for the basic blocks specified by the bitmap
2431 BLOCKS, or for the whole CFG if BLOCKS is zero, or just for the
2432 modified blocks if BLOCKS is -1. */
2434 df_analyse (df, blocks, flags)
2441 /* We could deal with additional basic blocks being created by
2442 rescanning everything again. */
2443 if (df->n_bbs && df->n_bbs != (unsigned int)n_basic_blocks)
2446 update = df_modified_p (df, blocks);
2447 if (update || (flags != df->flags))
2453 /* Recompute everything from scratch. */
2456 /* Allocate and initialise data structures. */
2457 df_alloc (df, max_reg_num ());
2458 df_analyse_1 (df, 0, flags, 0);
2463 if (blocks == (bitmap) -1)
2464 blocks = df->bbs_modified;
2469 df_analyse_1 (df, blocks, flags, 1);
2470 bitmap_zero (df->bbs_modified);
2477 /* Free all the dataflow info and the DF structure. */
2487 /* Unlink INSN from its reference information. */
2489 df_insn_refs_unlink (df, bb, insn)
2491 basic_block bb ATTRIBUTE_UNUSED;
2494 struct df_link *link;
2497 uid = INSN_UID (insn);
2499 /* Unlink all refs defined by this insn. */
2500 for (link = df->insns[uid].defs; link; link = link->next)
2501 df_def_unlink (df, link->ref);
2503 /* Unlink all refs used by this insn. */
2504 for (link = df->insns[uid].uses; link; link = link->next)
2505 df_use_unlink (df, link->ref);
2507 df->insns[uid].defs = 0;
2508 df->insns[uid].uses = 0;
2513 /* Unlink all the insns within BB from their reference information. */
2515 df_bb_refs_unlink (df, bb)
2521 /* Scan the block an insn at a time from beginning to end. */
2522 for (insn = bb->head; ; insn = NEXT_INSN (insn))
2526 /* Unlink refs for INSN. */
2527 df_insn_refs_unlink (df, bb, insn);
2529 if (insn == bb->end)
2535 /* Unlink all the refs in the basic blocks specified by BLOCKS.
2536 Not currently used. */
2538 df_refs_unlink (df, blocks)
2546 FOR_EACH_BB_IN_BITMAP (blocks, 0, bb,
2548 df_bb_refs_unlink (df, bb);
2555 df_bb_refs_unlink (df, bb);
2561 /* Functions to modify insns. */
2564 /* Delete INSN and all its reference information. */
2566 df_insn_delete (df, bb, insn)
2568 basic_block bb ATTRIBUTE_UNUSED;
2571 /* If the insn is a jump, we should perhaps call delete_insn to
2572 handle the JUMP_LABEL? */
2574 /* We should not be deleting the NOTE_INSN_BASIC_BLOCK or label. */
2575 if (insn == bb->head)
2577 if (insn == bb->end)
2578 bb->end = PREV_INSN (insn);
2580 /* Delete the insn. */
2581 PUT_CODE (insn, NOTE);
2582 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
2583 NOTE_SOURCE_FILE (insn) = 0;
2585 df_insn_modify (df, bb, insn);
2587 return NEXT_INSN (insn);
2591 /* Mark that INSN within BB may have changed (created/modified/deleted).
2592 This may be called multiple times for the same insn. There is no
2593 harm calling this function if the insn wasn't changed; it will just
2594 slow down the rescanning of refs. */
2596 df_insn_modify (df, bb, insn)
2603 uid = INSN_UID (insn);
2605 if (uid >= df->insn_size)
2606 df_insn_table_realloc (df, 0);
2608 bitmap_set_bit (df->bbs_modified, bb->index);
2609 bitmap_set_bit (df->insns_modified, uid);
2612 /* For incremental updating on the fly, perhaps we could make a copy
2613 of all the refs of the original insn and turn them into
2614 anti-refs. When df_refs_update finds these anti-refs, it annihilates
2615 the original refs. If validate_change fails then these anti-refs
2616 will just get ignored. */
2622 typedef struct replace_args
2631 /* Replace mem pointed to by PX with its associated pseudo register.
2632 DATA is actually a pointer to a structure describing the
2633 instruction currently being scanned and the MEM we are currently
2636 df_rtx_mem_replace (px, data)
2640 replace_args *args = (replace_args *) data;
2643 if (mem == NULL_RTX)
2646 switch (GET_CODE (mem))
2652 /* We're not interested in the MEM associated with a
2653 CONST_DOUBLE, so there's no need to traverse into one. */
2657 /* This is not a MEM. */
2661 if (!rtx_equal_p (args->match, mem))
2662 /* This is not the MEM we are currently replacing. */
2665 /* Actually replace the MEM. */
2666 validate_change (args->insn, px, args->replacement, 1);
2674 df_insn_mem_replace (df, bb, insn, mem, reg)
2685 args.replacement = reg;
2688 /* Seach and replace all matching mems within insn. */
2689 for_each_rtx (&insn, df_rtx_mem_replace, &args);
2692 df_insn_modify (df, bb, insn);
2694 /* ???? FIXME. We may have a new def or one or more new uses of REG
2695 in INSN. REG should be a new pseudo so it won't affect the
2696 dataflow information that we currently have. We should add
2697 the new uses and defs to INSN and then recreate the chains
2698 when df_analyse is called. */
2699 return args.modified;
2703 /* Replace one register with another. Called through for_each_rtx; PX
2704 points to the rtx being scanned. DATA is actually a pointer to a
2705 structure of arguments. */
2707 df_rtx_reg_replace (px, data)
2712 replace_args *args = (replace_args *) data;
2717 if (x == args->match)
2719 validate_change (args->insn, px, args->replacement, 1);
2727 /* Replace the reg within every ref on CHAIN that is within the set
2728 BLOCKS of basic blocks with NEWREG. Also update the regs within
2731 df_refs_reg_replace (df, blocks, chain, oldreg, newreg)
2734 struct df_link *chain;
2738 struct df_link *link;
2742 blocks = df->all_blocks;
2744 args.match = oldreg;
2745 args.replacement = newreg;
2748 for (link = chain; link; link = link->next)
2750 struct ref *ref = link->ref;
2751 rtx insn = DF_REF_INSN (ref);
2753 if (! INSN_P (insn))
2756 if (bitmap_bit_p (blocks, DF_REF_BBNO (ref)))
2758 df_ref_reg_replace (df, ref, oldreg, newreg);
2760 /* Replace occurrences of the reg within the REG_NOTES. */
2761 if ((! link->next || DF_REF_INSN (ref)
2762 != DF_REF_INSN (link->next->ref))
2763 && REG_NOTES (insn))
2766 for_each_rtx (®_NOTES (insn), df_rtx_reg_replace, &args);
2771 /* Temporary check to ensure that we have a grip on which
2772 regs should be replaced. */
2779 /* Replace all occurrences of register OLDREG with register NEWREG in
2780 blocks defined by bitmap BLOCKS. This also replaces occurrences of
2781 OLDREG in the REG_NOTES but only for insns containing OLDREG. This
2782 routine expects the reg-use and reg-def chains to be valid. */
2784 df_reg_replace (df, blocks, oldreg, newreg)
2790 unsigned int oldregno = REGNO (oldreg);
2792 df_refs_reg_replace (df, blocks, df->regs[oldregno].defs, oldreg, newreg);
2793 df_refs_reg_replace (df, blocks, df->regs[oldregno].uses, oldreg, newreg);
2798 /* Try replacing the reg within REF with NEWREG. Do not modify
2799 def-use/use-def chains. */
2801 df_ref_reg_replace (df, ref, oldreg, newreg)
2807 /* Check that insn was deleted by being converted into a NOTE. If
2808 so ignore this insn. */
2809 if (! INSN_P (DF_REF_INSN (ref)))
2812 if (oldreg && oldreg != DF_REF_REG (ref))
2815 if (! validate_change (DF_REF_INSN (ref), DF_REF_LOC (ref), newreg, 1))
2818 df_insn_modify (df, DF_REF_BB (ref), DF_REF_INSN (ref));
2824 df_bb_def_use_swap (df, bb, def_insn, use_insn, regno)
2835 struct df_link *link;
2837 def = df_bb_insn_regno_first_def_find (df, bb, def_insn, regno);
2841 use = df_bb_insn_regno_last_use_find (df, bb, use_insn, regno);
2845 /* The USE no longer exists. */
2846 use_uid = INSN_UID (use_insn);
2847 df_use_unlink (df, use);
2848 df_ref_unlink (&df->insns[use_uid].uses, use);
2850 /* The DEF requires shifting so remove it from DEF_INSN
2851 and add it to USE_INSN by reusing LINK. */
2852 def_uid = INSN_UID (def_insn);
2853 link = df_ref_unlink (&df->insns[def_uid].defs, def);
2855 link->next = df->insns[use_uid].defs;
2856 df->insns[use_uid].defs = link;
2859 link = df_ref_unlink (&df->regs[regno].defs, def);
2861 link->next = df->regs[regno].defs;
2862 df->insns[regno].defs = link;
2865 DF_REF_INSN (def) = use_insn;
2870 /* Record df between FIRST_INSN and LAST_INSN inclusive. All new
2871 insns must be processed by this routine. */
2873 df_insns_modify (df, bb, first_insn, last_insn)
2881 for (insn = first_insn; ; insn = NEXT_INSN (insn))
2885 /* A non-const call should not have slipped through the net. If
2886 it does, we need to create a new basic block. Ouch. The
2887 same applies for a label. */
2888 if ((GET_CODE (insn) == CALL_INSN
2889 && ! CONST_OR_PURE_CALL_P (insn))
2890 || GET_CODE (insn) == CODE_LABEL)
2893 uid = INSN_UID (insn);
2895 if (uid >= df->insn_size)
2896 df_insn_table_realloc (df, 0);
2898 df_insn_modify (df, bb, insn);
2900 if (insn == last_insn)
2906 /* Emit PATTERN before INSN within BB. */
2908 df_pattern_emit_before (df, pattern, bb, insn)
2909 struct df *df ATTRIBUTE_UNUSED;
2915 rtx prev_insn = PREV_INSN (insn);
2917 /* We should not be inserting before the start of the block. */
2918 if (insn == bb->head)
2920 ret_insn = emit_insn_before (pattern, insn);
2921 if (ret_insn == insn)
2924 df_insns_modify (df, bb, NEXT_INSN (prev_insn), ret_insn);
2929 /* Emit PATTERN after INSN within BB. */
2931 df_pattern_emit_after (df, pattern, bb, insn)
2939 ret_insn = emit_insn_after (pattern, insn);
2940 if (ret_insn == insn)
2943 if (bb->end == insn)
2946 df_insns_modify (df, bb, NEXT_INSN (insn), ret_insn);
2951 /* Emit jump PATTERN after INSN within BB. */
2953 df_jump_pattern_emit_after (df, pattern, bb, insn)
2961 ret_insn = emit_jump_insn_after (pattern, insn);
2962 if (ret_insn == insn)
2965 if (bb->end == insn)
2968 df_insns_modify (df, bb, NEXT_INSN (insn), ret_insn);
2973 /* Move INSN within BB before BEFORE_INSN within BEFORE_BB.
2975 This function should only be used to move loop invariant insns
2976 out of a loop where it has been proven that the def-use info
2977 will still be valid. */
2979 df_insn_move_before (df, bb, insn, before_bb, before_insn)
2983 basic_block before_bb;
2986 struct df_link *link;
2990 return df_pattern_emit_before (df, insn, before_bb, before_insn);
2992 uid = INSN_UID (insn);
2994 /* Change bb for all df defined and used by this insn. */
2995 for (link = df->insns[uid].defs; link; link = link->next)
2996 DF_REF_BB (link->ref) = before_bb;
2997 for (link = df->insns[uid].uses; link; link = link->next)
2998 DF_REF_BB (link->ref) = before_bb;
3000 /* The lifetimes of the registers used in this insn will be reduced
3001 while the lifetimes of the registers defined in this insn
3002 are likely to be increased. */
3004 /* ???? Perhaps all the insns moved should be stored on a list
3005 which df_analyse removes when it recalculates data flow. */
3007 return emit_block_insn_before (insn, before_insn, before_bb);
3010 /* Functions to query dataflow information. */
3014 df_insn_regno_def_p (df, bb, insn, regno)
3016 basic_block bb ATTRIBUTE_UNUSED;
3021 struct df_link *link;
3023 uid = INSN_UID (insn);
3025 for (link = df->insns[uid].defs; link; link = link->next)
3027 struct ref *def = link->ref;
3029 if (DF_REF_REGNO (def) == regno)
3038 df_def_dominates_all_uses_p (df, def)
3039 struct df *df ATTRIBUTE_UNUSED;
3042 struct df_link *du_link;
3044 /* Follow def-use chain to find all the uses of this def. */
3045 for (du_link = DF_REF_CHAIN (def); du_link; du_link = du_link->next)
3047 struct ref *use = du_link->ref;
3048 struct df_link *ud_link;
3050 /* Follow use-def chain to check all the defs for this use. */
3051 for (ud_link = DF_REF_CHAIN (use); ud_link; ud_link = ud_link->next)
3052 if (ud_link->ref != def)
3060 df_insn_dominates_all_uses_p (df, bb, insn)
3062 basic_block bb ATTRIBUTE_UNUSED;
3066 struct df_link *link;
3068 uid = INSN_UID (insn);
3070 for (link = df->insns[uid].defs; link; link = link->next)
3072 struct ref *def = link->ref;
3074 if (! df_def_dominates_all_uses_p (df, def))
3082 /* Return non-zero if all DF dominates all the uses within the bitmap
3085 df_def_dominates_uses_p (df, def, blocks)
3086 struct df *df ATTRIBUTE_UNUSED;
3090 struct df_link *du_link;
3092 /* Follow def-use chain to find all the uses of this def. */
3093 for (du_link = DF_REF_CHAIN (def); du_link; du_link = du_link->next)
3095 struct ref *use = du_link->ref;
3096 struct df_link *ud_link;
3098 /* Only worry about the uses within BLOCKS. For example,
3099 consider a register defined within a loop that is live at the
3101 if (bitmap_bit_p (blocks, DF_REF_BBNO (use)))
3103 /* Follow use-def chain to check all the defs for this use. */
3104 for (ud_link = DF_REF_CHAIN (use); ud_link; ud_link = ud_link->next)
3105 if (ud_link->ref != def)
3113 /* Return non-zero if all the defs of INSN within BB dominates
3114 all the corresponding uses. */
3116 df_insn_dominates_uses_p (df, bb, insn, blocks)
3118 basic_block bb ATTRIBUTE_UNUSED;
3123 struct df_link *link;
3125 uid = INSN_UID (insn);
3127 for (link = df->insns[uid].defs; link; link = link->next)
3129 struct ref *def = link->ref;
3131 /* Only consider the defs within BLOCKS. */
3132 if (bitmap_bit_p (blocks, DF_REF_BBNO (def))
3133 && ! df_def_dominates_uses_p (df, def, blocks))
3140 /* Return the basic block that REG referenced in or NULL if referenced
3141 in multiple basic blocks. */
3143 df_regno_bb (df, regno)
3147 struct df_link *defs = df->regs[regno].defs;
3148 struct df_link *uses = df->regs[regno].uses;
3149 struct ref *def = defs ? defs->ref : 0;
3150 struct ref *use = uses ? uses->ref : 0;
3151 basic_block bb_def = def ? DF_REF_BB (def) : 0;
3152 basic_block bb_use = use ? DF_REF_BB (use) : 0;
3154 /* Compare blocks of first def and last use. ???? FIXME. What if
3155 the reg-def and reg-use lists are not correctly ordered. */
3156 return bb_def == bb_use ? bb_def : 0;
3160 /* Return non-zero if REG used in multiple basic blocks. */
3162 df_reg_global_p (df, reg)
3166 return df_regno_bb (df, REGNO (reg)) != 0;
3170 /* Return total lifetime (in insns) of REG. */
3172 df_reg_lifetime (df, reg)
3176 return df->regs[REGNO (reg)].lifetime;
3180 /* Return non-zero if REG live at start of BB. */
3182 df_bb_reg_live_start_p (df, bb, reg)
3183 struct df *df ATTRIBUTE_UNUSED;
3187 struct bb_info *bb_info = DF_BB_INFO (df, bb);
3189 #ifdef ENABLE_CHECKING
3190 if (! bb_info->lr_in)
3194 return bitmap_bit_p (bb_info->lr_in, REGNO (reg));
3198 /* Return non-zero if REG live at end of BB. */
3200 df_bb_reg_live_end_p (df, bb, reg)
3201 struct df *df ATTRIBUTE_UNUSED;
3205 struct bb_info *bb_info = DF_BB_INFO (df, bb);
3207 #ifdef ENABLE_CHECKING
3208 if (! bb_info->lr_in)
3212 return bitmap_bit_p (bb_info->lr_out, REGNO (reg));
3216 /* Return -1 if life of REG1 before life of REG2, 1 if life of REG1
3217 after life of REG2, or 0, if the lives overlap. */
3219 df_bb_regs_lives_compare (df, bb, reg1, reg2)
3225 unsigned int regno1 = REGNO (reg1);
3226 unsigned int regno2 = REGNO (reg2);
3233 /* The regs must be local to BB. */
3234 if (df_regno_bb (df, regno1) != bb
3235 || df_regno_bb (df, regno2) != bb)
3238 def2 = df_bb_regno_first_def_find (df, bb, regno2);
3239 use1 = df_bb_regno_last_use_find (df, bb, regno1);
3241 if (DF_INSN_LUID (df, DF_REF_INSN (def2))
3242 > DF_INSN_LUID (df, DF_REF_INSN (use1)))
3245 def1 = df_bb_regno_first_def_find (df, bb, regno1);
3246 use2 = df_bb_regno_last_use_find (df, bb, regno2);
3248 if (DF_INSN_LUID (df, DF_REF_INSN (def1))
3249 > DF_INSN_LUID (df, DF_REF_INSN (use2)))
3256 /* Return last use of REGNO within BB. */
3258 df_bb_regno_last_use_find (df, bb, regno)
3260 basic_block bb ATTRIBUTE_UNUSED;
3263 struct df_link *link;
3265 /* This assumes that the reg-use list is ordered such that for any
3266 BB, the last use is found first. However, since the BBs are not
3267 ordered, the first use in the chain is not necessarily the last
3268 use in the function. */
3269 for (link = df->regs[regno].uses; link; link = link->next)
3271 struct ref *use = link->ref;
3273 if (DF_REF_BB (use) == bb)
3280 /* Return first def of REGNO within BB. */
3282 df_bb_regno_first_def_find (df, bb, regno)
3284 basic_block bb ATTRIBUTE_UNUSED;
3287 struct df_link *link;
3289 /* This assumes that the reg-def list is ordered such that for any
3290 BB, the first def is found first. However, since the BBs are not
3291 ordered, the first def in the chain is not necessarily the first
3292 def in the function. */
3293 for (link = df->regs[regno].defs; link; link = link->next)
3295 struct ref *def = link->ref;
3297 if (DF_REF_BB (def) == bb)
3304 /* Return first use of REGNO inside INSN within BB. */
3306 df_bb_insn_regno_last_use_find (df, bb, insn, regno)
3308 basic_block bb ATTRIBUTE_UNUSED;
3313 struct df_link *link;
3315 uid = INSN_UID (insn);
3317 for (link = df->insns[uid].uses; link; link = link->next)
3319 struct ref *use = link->ref;
3321 if (DF_REF_REGNO (use) == regno)
3329 /* Return first def of REGNO inside INSN within BB. */
3331 df_bb_insn_regno_first_def_find (df, bb, insn, regno)
3333 basic_block bb ATTRIBUTE_UNUSED;
3338 struct df_link *link;
3340 uid = INSN_UID (insn);
3342 for (link = df->insns[uid].defs; link; link = link->next)
3344 struct ref *def = link->ref;
3346 if (DF_REF_REGNO (def) == regno)
3354 /* Return insn using REG if the BB contains only a single
3355 use and def of REG. */
3357 df_bb_single_def_use_insn_find (df, bb, insn, reg)
3365 struct df_link *du_link;
3367 def = df_bb_insn_regno_first_def_find (df, bb, insn, REGNO (reg));
3372 du_link = DF_REF_CHAIN (def);
3379 /* Check if def is dead. */
3383 /* Check for multiple uses. */
3387 return DF_REF_INSN (use);
3390 /* Functions for debugging/dumping dataflow information. */
3393 /* Dump a def-use or use-def chain for REF to FILE. */
3395 df_chain_dump (link, file)
3396 struct df_link *link;
3399 fprintf (file, "{ ");
3400 for (; link; link = link->next)
3402 fprintf (file, "%c%d ",
3403 DF_REF_REG_DEF_P (link->ref) ? 'd' : 'u',
3404 DF_REF_ID (link->ref));
3406 fprintf (file, "}");
3410 df_chain_dump_regno (link, file)
3411 struct df_link *link;
3414 fprintf (file, "{ ");
3415 for (; link; link = link->next)
3417 fprintf (file, "%c%d(%d) ",
3418 DF_REF_REG_DEF_P (link->ref) ? 'd' : 'u',
3419 DF_REF_ID (link->ref),
3420 DF_REF_REGNO (link->ref));
3422 fprintf (file, "}");
3425 /* Dump dataflow info. */
3427 df_dump (df, flags, file)
3438 fprintf (file, "\nDataflow summary:\n");
3439 fprintf (file, "n_regs = %d, n_defs = %d, n_uses = %d, n_bbs = %d\n",
3440 df->n_regs, df->n_defs, df->n_uses, df->n_bbs);
3444 fprintf (file, "Reaching defs:\n");
3445 for (i = 0; i < df->n_bbs; i++)
3447 basic_block bb = BASIC_BLOCK (i);
3448 struct bb_info *bb_info = DF_BB_INFO (df, bb);
3450 if (! bb_info->rd_in)
3453 fprintf (file, "bb %d in \t", i);
3454 dump_bitmap (file, bb_info->rd_in);
3455 fprintf (file, "bb %d gen \t", i);
3456 dump_bitmap (file, bb_info->rd_gen);
3457 fprintf (file, "bb %d kill\t", i);
3458 dump_bitmap (file, bb_info->rd_kill);
3459 fprintf (file, "bb %d out \t", i);
3460 dump_bitmap (file, bb_info->rd_out);
3464 if (flags & DF_UD_CHAIN)
3466 fprintf (file, "Use-def chains:\n");
3467 for (j = 0; j < df->n_defs; j++)
3471 fprintf (file, "d%d bb %d luid %d insn %d reg %d ",
3472 j, DF_REF_BBNO (df->defs[j]),
3473 DF_INSN_LUID (df, DF_REF_INSN (df->defs[j])),
3474 DF_REF_INSN_UID (df->defs[j]),
3475 DF_REF_REGNO (df->defs[j]));
3476 df_chain_dump (DF_REF_CHAIN (df->defs[j]), file);
3477 fprintf (file, "\n");
3484 fprintf (file, "Reaching uses:\n");
3485 for (i = 0; i < df->n_bbs; i++)
3487 basic_block bb = BASIC_BLOCK (i);
3488 struct bb_info *bb_info = DF_BB_INFO (df, bb);
3490 if (! bb_info->ru_in)
3493 fprintf (file, "bb %d in \t", i);
3494 dump_bitmap (file, bb_info->ru_in);
3495 fprintf (file, "bb %d gen \t", i);
3496 dump_bitmap (file, bb_info->ru_gen);
3497 fprintf (file, "bb %d kill\t", i);
3498 dump_bitmap (file, bb_info->ru_kill);
3499 fprintf (file, "bb %d out \t", i);
3500 dump_bitmap (file, bb_info->ru_out);
3504 if (flags & DF_DU_CHAIN)
3506 fprintf (file, "Def-use chains:\n");
3507 for (j = 0; j < df->n_uses; j++)
3511 fprintf (file, "u%d bb %d luid %d insn %d reg %d ",
3512 j, DF_REF_BBNO (df->uses[j]),
3513 DF_INSN_LUID (df, DF_REF_INSN (df->uses[j])),
3514 DF_REF_INSN_UID (df->uses[j]),
3515 DF_REF_REGNO (df->uses[j]));
3516 df_chain_dump (DF_REF_CHAIN (df->uses[j]), file);
3517 fprintf (file, "\n");
3524 fprintf (file, "Live regs:\n");
3525 for (i = 0; i < df->n_bbs; i++)
3527 basic_block bb = BASIC_BLOCK (i);
3528 struct bb_info *bb_info = DF_BB_INFO (df, bb);
3530 if (! bb_info->lr_in)
3533 fprintf (file, "bb %d in \t", i);
3534 dump_bitmap (file, bb_info->lr_in);
3535 fprintf (file, "bb %d use \t", i);
3536 dump_bitmap (file, bb_info->lr_use);
3537 fprintf (file, "bb %d def \t", i);
3538 dump_bitmap (file, bb_info->lr_def);
3539 fprintf (file, "bb %d out \t", i);
3540 dump_bitmap (file, bb_info->lr_out);
3544 if (flags & (DF_REG_INFO | DF_RD_CHAIN | DF_RU_CHAIN))
3546 struct reg_info *reg_info = df->regs;
3548 fprintf (file, "Register info:\n");
3549 for (j = 0; j < df->n_regs; j++)
3551 if (((flags & DF_REG_INFO)
3552 && (reg_info[j].n_uses || reg_info[j].n_defs))
3553 || ((flags & DF_RD_CHAIN) && reg_info[j].defs)
3554 || ((flags & DF_RU_CHAIN) && reg_info[j].uses))
3556 fprintf (file, "reg %d", j);
3557 if ((flags & DF_RD_CHAIN) && (flags & DF_RU_CHAIN))
3559 basic_block bb = df_regno_bb (df, j);
3562 fprintf (file, " bb %d", bb->index);
3564 fprintf (file, " bb ?");
3566 if (flags & DF_REG_INFO)
3568 fprintf (file, " life %d", reg_info[j].lifetime);
3571 if ((flags & DF_REG_INFO) || (flags & DF_RD_CHAIN))
3573 fprintf (file, " defs ");
3574 if (flags & DF_REG_INFO)
3575 fprintf (file, "%d ", reg_info[j].n_defs);
3576 if (flags & DF_RD_CHAIN)
3577 df_chain_dump (reg_info[j].defs, file);
3580 if ((flags & DF_REG_INFO) || (flags & DF_RU_CHAIN))
3582 fprintf (file, " uses ");
3583 if (flags & DF_REG_INFO)
3584 fprintf (file, "%d ", reg_info[j].n_uses);
3585 if (flags & DF_RU_CHAIN)
3586 df_chain_dump (reg_info[j].uses, file);
3589 fprintf (file, "\n");
3593 fprintf (file, "\n");
3598 df_insn_debug (df, insn, file)
3606 uid = INSN_UID (insn);
3607 if (uid >= df->insn_size)
3610 if (df->insns[uid].defs)
3611 bbi = DF_REF_BBNO (df->insns[uid].defs->ref);
3612 else if (df->insns[uid].uses)
3613 bbi = DF_REF_BBNO (df->insns[uid].uses->ref);
3617 fprintf (file, "insn %d bb %d luid %d defs ",
3618 uid, bbi, DF_INSN_LUID (df, insn));
3619 df_chain_dump (df->insns[uid].defs, file);
3620 fprintf (file, " uses ");
3621 df_chain_dump (df->insns[uid].uses, file);
3622 fprintf (file, "\n");
3626 df_insn_debug_regno (df, insn, file)
3634 uid = INSN_UID (insn);
3635 if (uid >= df->insn_size)
3638 if (df->insns[uid].defs)
3639 bbi = DF_REF_BBNO (df->insns[uid].defs->ref);
3640 else if (df->insns[uid].uses)
3641 bbi = DF_REF_BBNO (df->insns[uid].uses->ref);
3645 fprintf (file, "insn %d bb %d luid %d defs ",
3646 uid, bbi, DF_INSN_LUID (df, insn));
3647 df_chain_dump_regno (df->insns[uid].defs, file);
3648 fprintf (file, " uses ");
3649 df_chain_dump_regno (df->insns[uid].uses, file);
3650 fprintf (file, "\n");
3654 df_regno_debug (df, regno, file)
3659 if (regno >= df->reg_size)
3662 fprintf (file, "reg %d life %d defs ",
3663 regno, df->regs[regno].lifetime);
3664 df_chain_dump (df->regs[regno].defs, file);
3665 fprintf (file, " uses ");
3666 df_chain_dump (df->regs[regno].uses, file);
3667 fprintf (file, "\n");
3672 df_ref_debug (df, ref, file)
3677 fprintf (file, "%c%d ",
3678 DF_REF_REG_DEF_P (ref) ? 'd' : 'u',
3680 fprintf (file, "reg %d bb %d luid %d insn %d chain ",
3683 DF_INSN_LUID (df, DF_REF_INSN (ref)),
3684 INSN_UID (DF_REF_INSN (ref)));
3685 df_chain_dump (DF_REF_CHAIN (ref), file);
3686 fprintf (file, "\n");
3691 debug_df_insn (insn)
3694 df_insn_debug (ddf, insn, stderr);
3703 df_regno_debug (ddf, REGNO (reg), stderr);
3708 debug_df_regno (regno)
3711 df_regno_debug (ddf, regno, stderr);
3719 df_ref_debug (ddf, ref, stderr);
3724 debug_df_defno (defno)
3727 df_ref_debug (ddf, ddf->defs[defno], stderr);
3732 debug_df_useno (defno)
3735 df_ref_debug (ddf, ddf->uses[defno], stderr);
3740 debug_df_chain (link)
3741 struct df_link *link;
3743 df_chain_dump (link, stderr);
3744 fputc ('\n', stderr);