1 /* Variable tracking routines for the GNU compiler.
2 Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
21 /* This file contains the variable tracking pass. It computes where
22 variables are located (which registers or where in memory) at each position
23 in instruction stream and emits notes describing the locations.
24 Debug information (DWARF2 location lists) is finally generated from
26 With this debug information, it is possible to show variables
27 even when debugging optimized code.
29 How does the variable tracking pass work?
31 First, it scans RTL code for uses, stores and clobbers (register/memory
32 references in instructions), for call insns and for stack adjustments
33 separately for each basic block and saves them to an array of micro
35 The micro operations of one instruction are ordered so that
36 pre-modifying stack adjustment < use < use with no var < call insn <
37 < set < clobber < post-modifying stack adjustment
39 Then, a forward dataflow analysis is performed to find out how locations
40 of variables change through code and to propagate the variable locations
41 along control flow graph.
42 The IN set for basic block BB is computed as a union of OUT sets of BB's
43 predecessors, the OUT set for BB is copied from the IN set for BB and
44 is changed according to micro operations in BB.
46 The IN and OUT sets for basic blocks consist of a current stack adjustment
47 (used for adjusting offset of variables addressed using stack pointer),
48 the table of structures describing the locations of parts of a variable
49 and for each physical register a linked list for each physical register.
50 The linked list is a list of variable parts stored in the register,
51 i.e. it is a list of triplets (reg, decl, offset) where decl is
52 REG_EXPR (reg) and offset is REG_OFFSET (reg). The linked list is used for
53 effective deleting appropriate variable parts when we set or clobber the
56 There may be more than one variable part in a register. The linked lists
57 should be pretty short so it is a good data structure here.
58 For example in the following code, register allocator may assign same
59 register to variables A and B, and both of them are stored in the same
72 Finally, the NOTE_INSN_VAR_LOCATION notes describing the variable locations
73 are emitted to appropriate positions in RTL code. Each such a note describes
74 the location of one variable at the point in instruction stream where the
75 note is. There is no need to emit a note for each variable before each
76 instruction, we only emit these notes where the location of variable changes
77 (this means that we also emit notes for changes between the OUT set of the
78 previous block and the IN set of the current block).
80 The notes consist of two parts:
81 1. the declaration (from REG_EXPR or MEM_EXPR)
82 2. the location of a variable - it is either a simple register/memory
83 reference (for simple variables, for example int),
84 or a parallel of register/memory references (for a large variables
85 which consist of several parts, for example long long).
91 #include "coretypes.h"
95 #include "hard-reg-set.h"
96 #include "basic-block.h"
99 #include "insn-config.h"
102 #include "alloc-pool.h"
106 /* Type of micro operation. */
107 enum micro_operation_type
109 MO_USE, /* Use location (REG or MEM). */
110 MO_USE_NO_VAR,/* Use location which is not associated with a variable
111 or the variable is not trackable. */
112 MO_SET, /* Set location. */
113 MO_CLOBBER, /* Clobber location. */
114 MO_CALL, /* Call insn. */
115 MO_ADJUST /* Adjust stack pointer. */
118 /* Where shall the note be emitted? BEFORE or AFTER the instruction. */
121 EMIT_NOTE_BEFORE_INSN,
125 /* Structure holding information about micro operation. */
126 typedef struct micro_operation_def
128 /* Type of micro operation. */
129 enum micro_operation_type type;
135 /* Stack adjustment. */
136 HOST_WIDE_INT adjust;
139 /* The instruction which the micro operation is in. */
143 /* Structure for passing some other parameters to function
144 emit_note_insn_var_location. */
145 typedef struct emit_note_data_def
147 /* The instruction which the note will be emitted before/after. */
150 /* Where the note will be emitted (before/after insn)? */
151 enum emit_note_where where;
154 /* Description of location of a part of a variable. The content of a physical
155 register is described by a chain of these structures.
156 The chains are pretty short (usually 1 or 2 elements) and thus
157 chain is the best data structure. */
158 typedef struct attrs_def
160 /* Pointer to next member of the list. */
161 struct attrs_def *next;
163 /* The rtx of register. */
166 /* The declaration corresponding to LOC. */
169 /* Offset from start of DECL. */
170 HOST_WIDE_INT offset;
173 /* Structure holding the IN or OUT set for a basic block. */
174 typedef struct dataflow_set_def
176 /* Adjustment of stack offset. */
177 HOST_WIDE_INT stack_adjust;
179 /* Attributes for registers (lists of attrs). */
180 attrs regs[FIRST_PSEUDO_REGISTER];
182 /* Variable locations. */
186 /* The structure (one for each basic block) containing the information
187 needed for variable tracking. */
188 typedef struct variable_tracking_info_def
190 /* Number of micro operations stored in the MOS array. */
193 /* The array of micro operations. */
194 micro_operation *mos;
196 /* The IN and OUT set for dataflow analysis. */
200 /* Has the block been visited in DFS? */
202 } *variable_tracking_info;
204 /* Structure for chaining the locations. */
205 typedef struct location_chain_def
207 /* Next element in the chain. */
208 struct location_chain_def *next;
210 /* The location (REG or MEM). */
214 /* Structure describing one part of variable. */
215 typedef struct variable_part_def
217 /* Chain of locations of the part. */
218 location_chain loc_chain;
220 /* Location which was last emitted to location list. */
223 /* The offset in the variable. */
224 HOST_WIDE_INT offset;
227 /* Maximum number of location parts. */
228 #define MAX_VAR_PARTS 16
230 /* Structure describing where the variable is located. */
231 typedef struct variable_def
233 /* The declaration of the variable. */
236 /* Number of variable parts. */
239 /* The variable parts. */
240 variable_part var_part[MAX_VAR_PARTS];
243 /* Hash function for DECL for VARIABLE_HTAB. */
244 #define VARIABLE_HASH_VAL(decl) ((size_t) (decl))
246 /* Pointer to the BB's information specific to variable tracking pass. */
247 #define VTI(BB) ((variable_tracking_info) (BB)->aux)
249 /* Alloc pool for struct attrs_def. */
250 static alloc_pool attrs_pool;
252 /* Alloc pool for struct variable_def. */
253 static alloc_pool var_pool;
255 /* Alloc pool for struct location_chain_def. */
256 static alloc_pool loc_chain_pool;
258 /* Changed variables, notes will be emitted for them. */
259 static htab_t changed_variables;
261 /* Shall notes be emitted? */
262 static bool emit_notes;
264 /* Fake variable for stack pointer. */
265 GTY(()) tree frame_base_decl;
267 /* Local function prototypes. */
268 static void stack_adjust_offset_pre_post (rtx, HOST_WIDE_INT *,
270 static void insn_stack_adjust_offset_pre_post (rtx, HOST_WIDE_INT *,
272 static void bb_stack_adjust_offset (basic_block);
273 static HOST_WIDE_INT prologue_stack_adjust (void);
274 static bool vt_stack_adjustments (void);
275 static rtx adjust_stack_reference (rtx, HOST_WIDE_INT);
276 static hashval_t variable_htab_hash (const void *);
277 static int variable_htab_eq (const void *, const void *);
278 static void variable_htab_free (void *);
280 static void init_attrs_list_set (attrs *);
281 static void attrs_list_clear (attrs *);
282 static attrs attrs_list_member (attrs, tree, HOST_WIDE_INT);
283 static void attrs_list_insert (attrs *, tree, HOST_WIDE_INT, rtx);
284 static void attrs_list_copy (attrs *, attrs);
285 static void attrs_list_union (attrs *, attrs);
287 static void vars_clear (htab_t);
288 static int vars_copy_1 (void **, void *);
289 static void vars_copy (htab_t, htab_t);
290 static void var_reg_delete_and_set (dataflow_set *, rtx);
291 static void var_reg_delete (dataflow_set *, rtx);
292 static void var_regno_delete (dataflow_set *, int);
293 static void var_mem_delete_and_set (dataflow_set *, rtx);
294 static void var_mem_delete (dataflow_set *, rtx);
296 static void dataflow_set_init (dataflow_set *, int);
297 static void dataflow_set_clear (dataflow_set *);
298 static void dataflow_set_copy (dataflow_set *, dataflow_set *);
299 static int variable_union_info_cmp_pos (const void *, const void *);
300 static int variable_union (void **, void *);
301 static void dataflow_set_union (dataflow_set *, dataflow_set *);
302 static bool variable_part_different_p (variable_part *, variable_part *);
303 static bool variable_different_p (variable, variable);
304 static int dataflow_set_different_1 (void **, void *);
305 static int dataflow_set_different_2 (void **, void *);
306 static bool dataflow_set_different (dataflow_set *, dataflow_set *);
307 static void dataflow_set_destroy (dataflow_set *);
309 static bool contains_symbol_ref (rtx);
310 static bool track_expr_p (tree);
311 static int count_uses (rtx *, void *);
312 static void count_uses_1 (rtx *, void *);
313 static void count_stores (rtx, rtx, void *);
314 static int add_uses (rtx *, void *);
315 static void add_uses_1 (rtx *, void *);
316 static void add_stores (rtx, rtx, void *);
317 static bool compute_bb_dataflow (basic_block);
318 static void vt_find_locations (void);
320 static void dump_attrs_list (attrs);
321 static int dump_variable (void **, void *);
322 static void dump_vars (htab_t);
323 static void dump_dataflow_set (dataflow_set *);
324 static void dump_dataflow_sets (void);
326 static void variable_was_changed (variable, htab_t);
327 static void set_frame_base_location (dataflow_set *, rtx);
328 static void set_variable_part (dataflow_set *, rtx, tree, HOST_WIDE_INT);
329 static void delete_variable_part (dataflow_set *, rtx, tree, HOST_WIDE_INT);
330 static int emit_note_insn_var_location (void **, void *);
331 static void emit_notes_for_changes (rtx, enum emit_note_where);
332 static int emit_notes_for_differences_1 (void **, void *);
333 static int emit_notes_for_differences_2 (void **, void *);
334 static void emit_notes_for_differences (rtx, dataflow_set *, dataflow_set *);
335 static void emit_notes_in_bb (basic_block);
336 static void vt_emit_notes (void);
338 static bool vt_get_decl_and_offset (rtx, tree *, HOST_WIDE_INT *);
339 static void vt_add_function_parameters (void);
340 static void vt_initialize (void);
341 static void vt_finalize (void);
343 /* Given a SET, calculate the amount of stack adjustment it contains
344 PRE- and POST-modifying stack pointer.
345 This function is similar to stack_adjust_offset. */
348 stack_adjust_offset_pre_post (rtx pattern, HOST_WIDE_INT *pre,
351 rtx src = SET_SRC (pattern);
352 rtx dest = SET_DEST (pattern);
355 if (dest == stack_pointer_rtx)
357 /* (set (reg sp) (plus (reg sp) (const_int))) */
358 code = GET_CODE (src);
359 if (! (code == PLUS || code == MINUS)
360 || XEXP (src, 0) != stack_pointer_rtx
361 || GET_CODE (XEXP (src, 1)) != CONST_INT)
365 *post += INTVAL (XEXP (src, 1));
367 *post -= INTVAL (XEXP (src, 1));
369 else if (GET_CODE (dest) == MEM)
371 /* (set (mem (pre_dec (reg sp))) (foo)) */
372 src = XEXP (dest, 0);
373 code = GET_CODE (src);
379 if (XEXP (src, 0) == stack_pointer_rtx)
381 rtx val = XEXP (XEXP (src, 1), 1);
382 /* We handle only adjustments by constant amount. */
383 if (GET_CODE (XEXP (src, 1)) != PLUS ||
384 GET_CODE (val) != CONST_INT)
386 if (code == PRE_MODIFY)
387 *pre -= INTVAL (val);
389 *post -= INTVAL (val);
395 if (XEXP (src, 0) == stack_pointer_rtx)
397 *pre += GET_MODE_SIZE (GET_MODE (dest));
403 if (XEXP (src, 0) == stack_pointer_rtx)
405 *post += GET_MODE_SIZE (GET_MODE (dest));
411 if (XEXP (src, 0) == stack_pointer_rtx)
413 *pre -= GET_MODE_SIZE (GET_MODE (dest));
419 if (XEXP (src, 0) == stack_pointer_rtx)
421 *post -= GET_MODE_SIZE (GET_MODE (dest));
432 /* Given an INSN, calculate the amount of stack adjustment it contains
433 PRE- and POST-modifying stack pointer. */
436 insn_stack_adjust_offset_pre_post (rtx insn, HOST_WIDE_INT *pre,
442 if (GET_CODE (PATTERN (insn)) == SET)
443 stack_adjust_offset_pre_post (PATTERN (insn), pre, post);
444 else if (GET_CODE (PATTERN (insn)) == PARALLEL
445 || GET_CODE (PATTERN (insn)) == SEQUENCE)
449 /* There may be stack adjustments inside compound insns. Search
451 for ( i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
452 if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET)
453 stack_adjust_offset_pre_post (XVECEXP (PATTERN (insn), 0, i),
458 /* Compute stack adjustment in basic block BB. */
461 bb_stack_adjust_offset (basic_block bb)
463 HOST_WIDE_INT offset;
466 offset = VTI (bb)->in.stack_adjust;
467 for (i = 0; i < VTI (bb)->n_mos; i++)
469 if (VTI (bb)->mos[i].type == MO_ADJUST)
470 offset += VTI (bb)->mos[i].u.adjust;
471 else if (VTI (bb)->mos[i].type != MO_CALL)
473 if (GET_CODE (VTI (bb)->mos[i].u.loc) == MEM)
475 VTI (bb)->mos[i].u.loc
476 = adjust_stack_reference (VTI (bb)->mos[i].u.loc, -offset);
480 VTI (bb)->out.stack_adjust = offset;
483 /* Compute stack adjustment caused by function prolog. */
486 prologue_stack_adjust (void)
488 HOST_WIDE_INT offset = 0;
489 basic_block bb = ENTRY_BLOCK_PTR->next_bb;
496 end = NEXT_INSN (BB_END (bb));
497 for (insn = BB_HEAD (bb); insn != end; insn = NEXT_INSN (insn))
499 if (GET_CODE (insn) == NOTE
500 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
507 insn_stack_adjust_offset_pre_post (insn, &tmp, &tmp);
515 /* Compute stack adjustments for all blocks by traversing DFS tree.
516 Return true when the adjustments on all incoming edges are consistent.
517 Heavily borrowed from flow_depth_first_order_compute. */
520 vt_stack_adjustments (void)
525 /* Initialize entry block. */
526 VTI (ENTRY_BLOCK_PTR)->visited = true;
527 VTI (ENTRY_BLOCK_PTR)->out.stack_adjust = 0;
529 /* Allocate stack for back-tracking up CFG. */
530 stack = xmalloc ((n_basic_blocks + 1) * sizeof (edge));
533 /* Push the first edge on to the stack. */
534 stack[sp++] = ENTRY_BLOCK_PTR->succ;
542 /* Look at the edge on the top of the stack. */
547 /* Check if the edge destination has been visited yet. */
548 if (!VTI (dest)->visited)
550 VTI (dest)->visited = true;
551 VTI (dest)->in.stack_adjust = VTI (src)->out.stack_adjust;
552 bb_stack_adjust_offset (dest);
555 /* Since the DEST node has been visited for the first
556 time, check its successors. */
557 stack[sp++] = dest->succ;
561 /* Check whether the adjustments on the edges are the same. */
562 if (VTI (dest)->in.stack_adjust != VTI (src)->out.stack_adjust)
569 /* Go to the next edge. */
570 stack[sp - 1] = e->succ_next;
572 /* Return to previous level if there are no more edges. */
581 /* Adjust stack reference MEM by ADJUSTMENT bytes and return the new rtx. */
584 adjust_stack_reference (rtx mem, HOST_WIDE_INT adjustment)
589 adjusted_mem = copy_rtx (mem);
590 XEXP (adjusted_mem, 0) = replace_rtx (XEXP (adjusted_mem, 0),
592 gen_rtx_PLUS (Pmode, stack_pointer_rtx,
593 GEN_INT (adjustment)));
594 tmp = simplify_rtx (XEXP (adjusted_mem, 0));
596 XEXP (adjusted_mem, 0) = tmp;
601 /* The hash function for variable_htab, computes the hash value
602 from the declaration of variable X. */
605 variable_htab_hash (const void *x)
607 const variable v = (const variable) x;
609 return (VARIABLE_HASH_VAL (v->decl));
612 /* Compare the declaration of variable X with declaration Y. */
615 variable_htab_eq (const void *x, const void *y)
617 const variable v = (const variable) x;
618 const tree decl = (const tree) y;
620 return (VARIABLE_HASH_VAL (v->decl) == VARIABLE_HASH_VAL (decl));
623 /* Free the element of VARIABLE_HTAB (its type is struct variable_def). */
626 variable_htab_free (void *elem)
629 variable var = (variable) elem;
630 location_chain node, next;
632 for (i = 0; i < var->n_var_parts; i++)
634 for (node = var->var_part[i].loc_chain; node; node = next)
637 pool_free (loc_chain_pool, node);
639 var->var_part[i].loc_chain = NULL;
641 pool_free (var_pool, var);
644 /* Initialize the set (array) SET of attrs to empty lists. */
647 init_attrs_list_set (attrs *set)
651 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
655 /* Make the list *LISTP empty. */
658 attrs_list_clear (attrs *listp)
662 for (list = *listp; list; list = next)
665 pool_free (attrs_pool, list);
670 /* Return true if the pair of DECL and OFFSET is the member of the LIST. */
673 attrs_list_member (attrs list, tree decl, HOST_WIDE_INT offset)
675 for (; list; list = list->next)
676 if (list->decl == decl && list->offset == offset)
681 /* Insert the triplet DECL, OFFSET, LOC to the list *LISTP. */
684 attrs_list_insert (attrs *listp, tree decl, HOST_WIDE_INT offset, rtx loc)
688 list = pool_alloc (attrs_pool);
691 list->offset = offset;
696 /* Copy all nodes from SRC and create a list *DSTP of the copies. */
699 attrs_list_copy (attrs *dstp, attrs src)
703 attrs_list_clear (dstp);
704 for (; src; src = src->next)
706 n = pool_alloc (attrs_pool);
709 n->offset = src->offset;
715 /* Add all nodes from SRC which are not in *DSTP to *DSTP. */
718 attrs_list_union (attrs *dstp, attrs src)
720 for (; src; src = src->next)
722 if (!attrs_list_member (*dstp, src->decl, src->offset))
723 attrs_list_insert (dstp, src->decl, src->offset, src->loc);
727 /* Delete all variables from hash table VARS. */
730 vars_clear (htab_t vars)
735 /* Copy one variable from *SLOT to hash table DATA. */
738 vars_copy_1 (void **slot, void *data)
740 htab_t dst = (htab_t) data;
741 variable src, *dstp, var;
744 src = *(variable *) slot;
745 dstp = (variable *) htab_find_slot_with_hash (dst, src->decl,
746 VARIABLE_HASH_VAL (src->decl),
748 var = pool_alloc (var_pool);
749 var->decl = src->decl;
750 var->n_var_parts = src->n_var_parts;
751 *dstp = (void *) var;
753 for (i = 0; i < var->n_var_parts; i++)
755 location_chain last, node;
757 var->var_part[i].offset = src->var_part[i].offset;
759 for (node = src->var_part[i].loc_chain; node; node = node->next)
761 location_chain new_lc;
763 new_lc = pool_alloc (loc_chain_pool);
765 new_lc->loc = node->loc;
770 var->var_part[i].loc_chain = new_lc;
774 /* We are at the basic block boundary when copying variable description
775 so set the CUR_LOC to be the first element of the chain. */
776 if (var->var_part[i].loc_chain)
777 var->var_part[i].cur_loc = var->var_part[i].loc_chain->loc;
779 var->var_part[i].cur_loc = NULL;
782 /* Continue traversing the hash table. */
786 /* Copy all variables from hash table SRC to hash table DST. */
789 vars_copy (htab_t dst, htab_t src)
792 htab_traverse (src, vars_copy_1, dst);
795 /* Delete current content of register LOC in dataflow set SET
796 and set the register to contain REG_EXPR (LOC), REG_OFFSET (LOC). */
799 var_reg_delete_and_set (dataflow_set *set, rtx loc)
801 attrs *reg = &set->regs[REGNO (loc)];
802 tree decl = REG_EXPR (loc);
803 HOST_WIDE_INT offset = REG_OFFSET (loc);
804 attrs node, prev, next;
807 for (node = *reg; node; node = next)
810 if (node->decl != decl || node->offset != offset)
812 delete_variable_part (set, node->loc, node->decl, node->offset);
818 pool_free (attrs_pool, node);
827 attrs_list_insert (reg, decl, offset, loc);
828 set_variable_part (set, loc, decl, offset);
831 /* Delete current content of register LOC in dataflow set SET. */
834 var_reg_delete (dataflow_set *set, rtx loc)
836 attrs *reg = &set->regs[REGNO (loc)];
839 for (node = *reg; node; node = next)
842 delete_variable_part (set, node->loc, node->decl, node->offset);
843 pool_free (attrs_pool, node);
848 /* Delete content of register with number REGNO in dataflow set SET. */
851 var_regno_delete (dataflow_set *set, int regno)
853 attrs *reg = &set->regs[regno];
856 for (node = *reg; node; node = next)
859 delete_variable_part (set, node->loc, node->decl, node->offset);
860 pool_free (attrs_pool, node);
865 /* Delete and set the location part of variable MEM_EXPR (LOC)
866 in dataflow set SET to LOC.
867 Adjust the address first if it is stack pointer based. */
870 var_mem_delete_and_set (dataflow_set *set, rtx loc)
872 tree decl = MEM_EXPR (loc);
873 HOST_WIDE_INT offset = MEM_OFFSET (loc) ? INTVAL (MEM_OFFSET (loc)) : 0;
875 set_variable_part (set, loc, decl, offset);
878 /* Delete the location part LOC from dataflow set SET.
879 Adjust the address first if it is stack pointer based. */
882 var_mem_delete (dataflow_set *set, rtx loc)
884 tree decl = MEM_EXPR (loc);
885 HOST_WIDE_INT offset = MEM_OFFSET (loc) ? INTVAL (MEM_OFFSET (loc)) : 0;
887 delete_variable_part (set, loc, decl, offset);
890 /* Initialize dataflow set SET to be empty.
891 VARS_SIZE is the initial size of hash table VARS. */
894 dataflow_set_init (dataflow_set *set, int vars_size)
896 init_attrs_list_set (set->regs);
897 set->vars = htab_create (vars_size, variable_htab_hash, variable_htab_eq,
899 set->stack_adjust = 0;
902 /* Delete the contents of dataflow set SET. */
905 dataflow_set_clear (dataflow_set *set)
909 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
910 attrs_list_clear (&set->regs[i]);
912 vars_clear (set->vars);
915 /* Copy the contents of dataflow set SRC to DST. */
918 dataflow_set_copy (dataflow_set *dst, dataflow_set *src)
922 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
923 attrs_list_copy (&dst->regs[i], src->regs[i]);
925 vars_copy (dst->vars, src->vars);
926 dst->stack_adjust = src->stack_adjust;
929 /* Information for merging lists of locations for a given offset of variable.
931 struct variable_union_info
933 /* Node of the location chain. */
936 /* The sum of positions in the input chains. */
939 /* The position in the chains of SRC and DST dataflow sets. */
944 /* Compare function for qsort, order the structures by POS element. */
947 variable_union_info_cmp_pos (const void *n1, const void *n2)
949 const struct variable_union_info *i1 = n1;
950 const struct variable_union_info *i2 = n2;
952 if (i1->pos != i2->pos)
953 return i1->pos - i2->pos;
955 return (i1->pos_dst - i2->pos_dst);
958 /* Compute union of location parts of variable *SLOT and the same variable
959 from hash table DATA. Compute "sorted" union of the location chains
960 for common offsets, i.e. the locations of a variable part are sorted by
961 a priority where the priority is the sum of the positions in the 2 chains
962 (if a location is only in one list the position in the second list is
963 defined to be larger than the length of the chains).
964 When we are updating the location parts the newest location is in the
965 beginning of the chain, so when we do the described "sorted" union
966 we keep the newest locations in the beginning. */
969 variable_union (void **slot, void *data)
971 variable src, dst, *dstp;
972 dataflow_set *set = (dataflow_set *) data;
975 src = *(variable *) slot;
976 dstp = (variable *) htab_find_slot_with_hash (set->vars, src->decl,
977 VARIABLE_HASH_VAL (src->decl),
981 *dstp = dst = pool_alloc (var_pool);
982 dst->decl = src->decl;
983 dst->n_var_parts = 0;
988 #ifdef ENABLE_CHECKING
989 if (src->n_var_parts == 0)
993 /* Count the number of location parts, result is K. */
994 for (i = 0, j = 0, k = 0;
995 i < src->n_var_parts && j < dst->n_var_parts; k++)
997 if (src->var_part[i].offset == dst->var_part[j].offset)
1002 else if (src->var_part[i].offset < dst->var_part[j].offset)
1007 if (i < src->n_var_parts)
1008 k += src->n_var_parts - i;
1009 if (j < dst->n_var_parts)
1010 k += dst->n_var_parts - j;
1011 #ifdef ENABLE_CHECKING
1012 /* We track only variables whose size is <= MAX_VAR_PARTS bytes
1013 thus there are at most MAX_VAR_PARTS different offsets. */
1014 if (k > MAX_VAR_PARTS)
1018 i = src->n_var_parts - 1;
1019 j = dst->n_var_parts - 1;
1020 dst->n_var_parts = k;
1022 for (k--; k >= 0; k--)
1024 location_chain node;
1026 if (i >= 0 && j >= 0
1027 && src->var_part[i].offset == dst->var_part[j].offset)
1029 /* Compute the "sorted" union of the chains, i.e. the locations which
1030 are in both chains go first, they are sorted by the sum of
1031 positions in the chains. */
1034 struct variable_union_info *vui;
1037 for (node = src->var_part[i].loc_chain; node; node = node->next)
1040 for (node = dst->var_part[j].loc_chain; node; node = node->next)
1042 vui = xcalloc (src_l + dst_l, sizeof (struct variable_union_info));
1044 /* Fill in the locations from DST. */
1045 for (node = dst->var_part[j].loc_chain, jj = 0; node;
1046 node = node->next, jj++)
1049 vui[jj].pos_dst = jj;
1051 /* Value larger than a sum of 2 valid positions. */
1052 vui[jj].pos_src = src_l + dst_l;
1055 /* Fill in the locations from SRC. */
1057 for (node = src->var_part[i].loc_chain, ii = 0; node;
1058 node = node->next, ii++)
1060 /* Find location from NODE. */
1061 for (jj = 0; jj < dst_l; jj++)
1063 if ((GET_CODE (vui[jj].lc->loc) == REG
1064 && GET_CODE (node->loc) == REG
1065 && REGNO (vui[jj].lc->loc) == REGNO (node->loc))
1066 || rtx_equal_p (vui[jj].lc->loc, node->loc))
1068 vui[jj].pos_src = ii;
1072 if (jj >= dst_l) /* The location has not been found. */
1074 location_chain new_node;
1076 /* Copy the location from SRC. */
1077 new_node = pool_alloc (loc_chain_pool);
1078 new_node->loc = node->loc;
1079 vui[n].lc = new_node;
1080 vui[n].pos_src = ii;
1081 vui[n].pos_dst = src_l + dst_l;
1086 for (ii = 0; ii < src_l + dst_l; ii++)
1087 vui[ii].pos = vui[ii].pos_src + vui[ii].pos_dst;
1089 qsort (vui, n, sizeof (struct variable_union_info),
1090 variable_union_info_cmp_pos);
1092 /* Reconnect the nodes in sorted order. */
1093 for (ii = 1; ii < n; ii++)
1094 vui[ii - 1].lc->next = vui[ii].lc;
1095 vui[n - 1].lc->next = NULL;
1097 dst->var_part[k].loc_chain = vui[0].lc;
1098 dst->var_part[k].offset = dst->var_part[j].offset;
1104 else if ((i >= 0 && j >= 0
1105 && src->var_part[i].offset < dst->var_part[j].offset)
1108 dst->var_part[k] = dst->var_part[j];
1111 else if ((i >= 0 && j >= 0
1112 && src->var_part[i].offset > dst->var_part[j].offset)
1115 location_chain last = NULL;
1117 /* Copy the chain from SRC. */
1118 for (node = src->var_part[i].loc_chain; node; node = node->next)
1120 location_chain new_lc;
1122 new_lc = pool_alloc (loc_chain_pool);
1123 new_lc->next = NULL;
1124 new_lc->loc = node->loc;
1127 last->next = new_lc;
1129 dst->var_part[k].loc_chain = new_lc;
1133 dst->var_part[k].offset = src->var_part[i].offset;
1137 /* We are at the basic block boundary when computing union
1138 so set the CUR_LOC to be the first element of the chain. */
1139 if (dst->var_part[k].loc_chain)
1140 dst->var_part[k].cur_loc = dst->var_part[k].loc_chain->loc;
1142 dst->var_part[k].cur_loc = NULL;
1145 /* Continue traversing the hash table. */
1149 /* Compute union of dataflow sets SRC and DST and store it to DST. */
1152 dataflow_set_union (dataflow_set *dst, dataflow_set *src)
1156 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1157 attrs_list_union (&dst->regs[i], src->regs[i]);
1159 htab_traverse (src->vars, variable_union, dst);
1162 /* Flag whether two dataflow sets being compared contain different data. */
1164 dataflow_set_different_value;
1167 variable_part_different_p (variable_part *vp1, variable_part *vp2)
1169 location_chain lc1, lc2;
1171 for (lc1 = vp1->loc_chain; lc1; lc1 = lc1->next)
1173 for (lc2 = vp2->loc_chain; lc2; lc2 = lc2->next)
1175 if (GET_CODE (lc1->loc) == REG && GET_CODE (lc2->loc) == REG)
1177 if (REGNO (lc1->loc) == REGNO (lc2->loc))
1180 if (rtx_equal_p (lc1->loc, lc2->loc))
1189 /* Return true if variables VAR1 and VAR2 are different (only the first
1190 location in the list of locations is checked for each offset,
1191 i.e. when true is returned a note should be emitted). */
1194 variable_different_p (variable var1, variable var2)
1198 if (var1->n_var_parts != var2->n_var_parts)
1201 for (i = 0; i < var1->n_var_parts; i++)
1203 if (var1->var_part[i].offset != var2->var_part[i].offset)
1205 if (variable_part_different_p (&var1->var_part[i], &var2->var_part[i]))
1207 if (variable_part_different_p (&var2->var_part[i], &var1->var_part[i]))
1213 /* Compare variable *SLOT with the same variable in hash table DATA
1214 and set DATAFLOW_SET_DIFFERENT_VALUE if they are different. */
1217 dataflow_set_different_1 (void **slot, void *data)
1219 htab_t htab = (htab_t) data;
1220 variable var1, var2;
1222 var1 = *(variable *) slot;
1223 var2 = (variable) htab_find_with_hash (htab, var1->decl,
1224 VARIABLE_HASH_VAL (var1->decl));
1227 dataflow_set_different_value = true;
1229 /* Stop traversing the hash table. */
1233 if (variable_different_p (var1, var2))
1235 dataflow_set_different_value = true;
1237 /* Stop traversing the hash table. */
1241 /* Continue traversing the hash table. */
1245 /* Compare variable *SLOT with the same variable in hash table DATA
1246 and set DATAFLOW_SET_DIFFERENT_VALUE if they are different. */
1249 dataflow_set_different_2 (void **slot, void *data)
1251 htab_t htab = (htab_t) data;
1252 variable var1, var2;
1254 var1 = *(variable *) slot;
1255 var2 = (variable) htab_find_with_hash (htab, var1->decl,
1256 VARIABLE_HASH_VAL (var1->decl));
1259 dataflow_set_different_value = true;
1261 /* Stop traversing the hash table. */
1265 #ifdef ENABLE_CHECKING
1266 /* If both variables are defined they have been already checked for
1268 if (variable_different_p (var1, var2))
1272 /* Continue traversing the hash table. */
1276 /* Return true if dataflow sets OLD_SET and NEW_SET differ. */
1279 dataflow_set_different (dataflow_set *old_set, dataflow_set *new_set)
1281 dataflow_set_different_value = false;
1283 htab_traverse (old_set->vars, dataflow_set_different_1, new_set->vars);
1284 if (!dataflow_set_different_value)
1286 /* We have compared the variables which are in both hash tables
1287 so now only check whether there are some variables in NEW_SET->VARS
1288 which are not in OLD_SET->VARS. */
1289 htab_traverse (new_set->vars, dataflow_set_different_2, old_set->vars);
1291 return dataflow_set_different_value;
1294 /* Free the contents of dataflow set SET. */
1297 dataflow_set_destroy (dataflow_set *set)
1301 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1302 attrs_list_clear (&set->regs[i]);
1304 htab_delete (set->vars);
1308 /* Return true if RTL X contains a SYMBOL_REF. */
1311 contains_symbol_ref (rtx x)
1320 code = GET_CODE (x);
1321 if (code == SYMBOL_REF)
1324 fmt = GET_RTX_FORMAT (code);
1325 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1329 if (contains_symbol_ref (XEXP (x, i)))
1332 else if (fmt[i] == 'E')
1335 for (j = 0; j < XVECLEN (x, i); j++)
1336 if (contains_symbol_ref (XVECEXP (x, i, j)))
1344 /* Shall EXPR be tracked? */
1347 track_expr_p (tree expr)
1351 /* If EXPR is not a parameter or a variable do not track it. */
1352 if (TREE_CODE (expr) != VAR_DECL && TREE_CODE (expr) != PARM_DECL)
1355 /* It also must have a name... */
1356 if (!DECL_NAME (expr))
1359 /* ... and a RTL assigned to it. */
1360 decl_rtl = DECL_RTL_IF_SET (expr);
1364 /* Do not track global variables until we are able to emit correct location
1366 if (TREE_STATIC (expr))
1369 /* When the EXPR is a DECL for alias of some variable (see example)
1370 the TREE_STATIC flag is not used. Disable tracking all DECLs whose
1371 DECL_RTL contains SYMBOL_REF.
1374 extern char **_dl_argv_internal __attribute__ ((alias ("_dl_argv")));
1377 if (GET_CODE (decl_rtl) == MEM
1378 && contains_symbol_ref (XEXP (decl_rtl, 0)))
1381 /* If RTX is a memory it should not be very large (because it would be
1382 an array or struct). */
1383 if (GET_CODE (decl_rtl) == MEM)
1385 /* Do not track structures and arrays. */
1386 if (GET_MODE (decl_rtl) == BLKmode)
1388 if (MEM_SIZE (decl_rtl)
1389 && INTVAL (MEM_SIZE (decl_rtl)) > MAX_VAR_PARTS)
1396 /* Count uses (register and memory references) LOC which will be tracked.
1397 INSN is instruction which the LOC is part of. */
1400 count_uses (rtx *loc, void *insn)
1402 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1404 if (GET_CODE (*loc) == REG)
1406 #ifdef ENABLE_CHECKING
1407 if (REGNO (*loc) >= FIRST_PSEUDO_REGISTER)
1412 else if (GET_CODE (*loc) == MEM
1414 && track_expr_p (MEM_EXPR (*loc)))
1422 /* Helper function for finding all uses of REG/MEM in X in insn INSN. */
1425 count_uses_1 (rtx *x, void *insn)
1427 for_each_rtx (x, count_uses, insn);
1430 /* Count stores (register and memory references) LOC which will be tracked.
1431 INSN is instruction which the LOC is part of. */
1434 count_stores (rtx loc, rtx expr ATTRIBUTE_UNUSED, void *insn)
1436 count_uses (&loc, insn);
1439 /* Add uses (register and memory references) LOC which will be tracked
1440 to VTI (bb)->mos. INSN is instruction which the LOC is part of. */
1443 add_uses (rtx *loc, void *insn)
1445 if (GET_CODE (*loc) == REG)
1447 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1448 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1450 mo->type = ((REG_EXPR (*loc) && track_expr_p (REG_EXPR (*loc)))
1451 ? MO_USE : MO_USE_NO_VAR);
1453 mo->insn = (rtx) insn;
1455 else if (GET_CODE (*loc) == MEM
1457 && track_expr_p (MEM_EXPR (*loc)))
1459 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1460 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1464 mo->insn = (rtx) insn;
1470 /* Helper function for finding all uses of REG/MEM in X in insn INSN. */
1473 add_uses_1 (rtx *x, void *insn)
1475 for_each_rtx (x, add_uses, insn);
1478 /* Add stores (register and memory references) LOC which will be tracked
1479 to VTI (bb)->mos. EXPR is the RTL expression containing the store.
1480 INSN is instruction which the LOC is part of. */
1483 add_stores (rtx loc, rtx expr, void *insn)
1485 if (GET_CODE (loc) == REG)
1487 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1488 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1490 mo->type = ((GET_CODE (expr) != CLOBBER && REG_EXPR (loc)
1491 && track_expr_p (REG_EXPR (loc)))
1492 ? MO_SET : MO_CLOBBER);
1494 mo->insn = (rtx) insn;
1496 else if (GET_CODE (loc) == MEM
1498 && track_expr_p (MEM_EXPR (loc)))
1500 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1501 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1503 mo->type = GET_CODE (expr) == CLOBBER ? MO_CLOBBER : MO_SET;
1505 mo->insn = (rtx) insn;
1509 /* Compute the changes of variable locations in the basic block BB. */
1512 compute_bb_dataflow (basic_block bb)
1516 dataflow_set old_out;
1517 dataflow_set *in = &VTI (bb)->in;
1518 dataflow_set *out = &VTI (bb)->out;
1520 dataflow_set_init (&old_out, htab_elements (VTI (bb)->out.vars) + 3);
1521 dataflow_set_copy (&old_out, out);
1522 dataflow_set_copy (out, in);
1524 n = VTI (bb)->n_mos;
1525 for (i = 0; i < n; i++)
1527 switch (VTI (bb)->mos[i].type)
1530 for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
1531 if (TEST_HARD_REG_BIT (call_used_reg_set, r))
1532 var_regno_delete (out, r);
1538 rtx loc = VTI (bb)->mos[i].u.loc;
1540 if (GET_CODE (loc) == REG)
1541 var_reg_delete_and_set (out, loc);
1542 else if (GET_CODE (loc) == MEM)
1543 var_mem_delete_and_set (out, loc);
1550 rtx loc = VTI (bb)->mos[i].u.loc;
1552 if (GET_CODE (loc) == REG)
1553 var_reg_delete (out, loc);
1554 else if (GET_CODE (loc) == MEM)
1555 var_mem_delete (out, loc);
1563 out->stack_adjust += VTI (bb)->mos[i].u.adjust;
1564 base = gen_rtx_MEM (Pmode,
1565 gen_rtx_PLUS (Pmode, stack_pointer_rtx,
1566 GEN_INT (out->stack_adjust)));
1567 set_frame_base_location (out, base);
1573 changed = dataflow_set_different (&old_out, out);
1574 dataflow_set_destroy (&old_out);
1578 /* Find the locations of variables in the whole function. */
1581 vt_find_locations (void)
1583 fibheap_t worklist, pending, fibheap_swap;
1584 sbitmap visited, in_worklist, in_pending, sbitmap_swap;
1591 /* Compute reverse completion order of depth first search of the CFG
1592 so that the data-flow runs faster. */
1593 rc_order = (int *) xmalloc (n_basic_blocks * sizeof (int));
1594 bb_order = (int *) xmalloc (last_basic_block * sizeof (int));
1595 flow_depth_first_order_compute (NULL, rc_order);
1596 for (i = 0; i < n_basic_blocks; i++)
1597 bb_order[rc_order[i]] = i;
1600 worklist = fibheap_new ();
1601 pending = fibheap_new ();
1602 visited = sbitmap_alloc (last_basic_block);
1603 in_worklist = sbitmap_alloc (last_basic_block);
1604 in_pending = sbitmap_alloc (last_basic_block);
1605 sbitmap_zero (in_worklist);
1606 sbitmap_zero (in_pending);
1610 fibheap_insert (pending, bb_order[bb->index], bb);
1611 SET_BIT (in_pending, bb->index);
1614 while (!fibheap_empty (pending))
1616 fibheap_swap = pending;
1618 worklist = fibheap_swap;
1619 sbitmap_swap = in_pending;
1620 in_pending = in_worklist;
1621 in_worklist = sbitmap_swap;
1623 sbitmap_zero (visited);
1625 while (!fibheap_empty (worklist))
1627 bb = fibheap_extract_min (worklist);
1628 RESET_BIT (in_worklist, bb->index);
1629 if (!TEST_BIT (visited, bb->index))
1633 SET_BIT (visited, bb->index);
1635 /* Calculate the IN set as union of predecessor OUT sets. */
1636 dataflow_set_clear (&VTI (bb)->in);
1637 for (e = bb->pred; e; e = e->pred_next)
1639 dataflow_set_union (&VTI (bb)->in, &VTI (e->src)->out);
1642 changed = compute_bb_dataflow (bb);
1645 for (e = bb->succ; e; e = e->succ_next)
1647 if (e->dest == EXIT_BLOCK_PTR)
1653 if (TEST_BIT (visited, e->dest->index))
1655 if (!TEST_BIT (in_pending, e->dest->index))
1657 /* Send E->DEST to next round. */
1658 SET_BIT (in_pending, e->dest->index);
1659 fibheap_insert (pending,
1660 bb_order[e->dest->index],
1664 else if (!TEST_BIT (in_worklist, e->dest->index))
1666 /* Add E->DEST to current round. */
1667 SET_BIT (in_worklist, e->dest->index);
1668 fibheap_insert (worklist, bb_order[e->dest->index],
1678 fibheap_delete (worklist);
1679 fibheap_delete (pending);
1680 sbitmap_free (visited);
1681 sbitmap_free (in_worklist);
1682 sbitmap_free (in_pending);
1685 /* Print the content of the LIST to dump file. */
1688 dump_attrs_list (attrs list)
1690 for (; list; list = list->next)
1692 print_mem_expr (rtl_dump_file, list->decl);
1693 fprintf (rtl_dump_file, "+");
1694 fprintf (rtl_dump_file, HOST_WIDE_INT_PRINT_DEC, list->offset);
1696 fprintf (rtl_dump_file, "\n");
1699 /* Print the information about variable *SLOT to dump file. */
1702 dump_variable (void **slot, void *data ATTRIBUTE_UNUSED)
1704 variable var = *(variable *) slot;
1706 location_chain node;
1708 fprintf (rtl_dump_file, " name: %s\n",
1709 IDENTIFIER_POINTER (DECL_NAME (var->decl)));
1710 for (i = 0; i < var->n_var_parts; i++)
1712 fprintf (rtl_dump_file, " offset %ld\n",
1713 (long) var->var_part[i].offset);
1714 for (node = var->var_part[i].loc_chain; node; node = node->next)
1716 fprintf (rtl_dump_file, " ");
1717 print_rtl_single (rtl_dump_file, node->loc);
1721 /* Continue traversing the hash table. */
1725 /* Print the information about variables from hash table VARS to dump file. */
1728 dump_vars (htab_t vars)
1730 if (htab_elements (vars) > 0)
1732 fprintf (rtl_dump_file, "Variables:\n");
1733 htab_traverse (vars, dump_variable, NULL);
1737 /* Print the dataflow set SET to dump file. */
1740 dump_dataflow_set (dataflow_set *set)
1744 fprintf (rtl_dump_file, "Stack adjustment: ");
1745 fprintf (rtl_dump_file, HOST_WIDE_INT_PRINT_DEC, set->stack_adjust);
1746 fprintf (rtl_dump_file, "\n");
1747 for (i = 1; i < FIRST_PSEUDO_REGISTER; i++)
1751 fprintf (rtl_dump_file, "Reg %d:", i);
1752 dump_attrs_list (set->regs[i]);
1755 dump_vars (set->vars);
1756 fprintf (rtl_dump_file, "\n");
1759 /* Print the IN and OUT sets for each basic block to dump file. */
1762 dump_dataflow_sets (void)
1768 fprintf (rtl_dump_file, "\nBasic block %d:\n", bb->index);
1769 fprintf (rtl_dump_file, "IN:\n");
1770 dump_dataflow_set (&VTI (bb)->in);
1771 fprintf (rtl_dump_file, "OUT:\n");
1772 dump_dataflow_set (&VTI (bb)->out);
1776 /* Add variable VAR to the hash table of changed variables and
1777 if it has no locations delete it from hash table HTAB. */
1780 variable_was_changed (variable var, htab_t htab)
1782 hashval_t hash = VARIABLE_HASH_VAL (var->decl);
1788 slot = (variable *) htab_find_slot_with_hash (changed_variables,
1789 var->decl, hash, INSERT);
1791 if (htab && var->n_var_parts == 0)
1796 empty_var = pool_alloc (var_pool);
1797 empty_var->decl = var->decl;
1798 empty_var->n_var_parts = 0;
1801 old = htab_find_slot_with_hash (htab, var->decl, hash,
1804 htab_clear_slot (htab, old);
1813 #ifdef ENABLE_CHECKING
1817 if (var->n_var_parts == 0)
1819 void **slot = htab_find_slot_with_hash (htab, var->decl, hash,
1822 htab_clear_slot (htab, slot);
1827 /* Set the location of frame_base_decl to LOC in dataflow set SET. This
1828 function expects that
1829 frame_base_decl has already one location for offset 0 in the variable table.
1833 set_frame_base_location (dataflow_set *set, rtx loc)
1837 var = htab_find_with_hash (set->vars, frame_base_decl,
1838 VARIABLE_HASH_VAL (frame_base_decl));
1839 #ifdef ENABLE_CHECKING
1842 if (var->n_var_parts != 1)
1844 if (var->var_part[0].offset != 0)
1846 if (!var->var_part[0].loc_chain)
1850 var->var_part[0].loc_chain->loc = loc;
1851 variable_was_changed (var, set->vars);
1854 /* Set the part of variable's location in the dataflow set SET. The variable
1855 part is specified by variable's declaration DECL and offset OFFSET and the
1856 part's location by LOC. */
1859 set_variable_part (dataflow_set *set, rtx loc, tree decl, HOST_WIDE_INT offset)
1862 location_chain node, prev, next;
1866 slot = htab_find_slot_with_hash (set->vars, decl,
1867 VARIABLE_HASH_VAL (decl), INSERT);
1870 /* Create new variable information. */
1871 var = pool_alloc (var_pool);
1873 var->n_var_parts = 1;
1874 var->var_part[0].offset = offset;
1875 var->var_part[0].loc_chain = NULL;
1876 var->var_part[0].cur_loc = NULL;
1882 var = (variable) *slot;
1884 /* Find the location part. */
1886 high = var->n_var_parts;
1889 pos = (low + high) / 2;
1890 if (var->var_part[pos].offset < offset)
1897 if (pos == var->n_var_parts || var->var_part[pos].offset != offset)
1899 /* We have not find the location part, new one will be created. */
1901 #ifdef ENABLE_CHECKING
1902 /* We track only variables whose size is <= MAX_VAR_PARTS bytes
1903 thus there are at most MAX_VAR_PARTS different offsets. */
1904 if (var->n_var_parts >= MAX_VAR_PARTS)
1908 /* We have to move the elements of array starting at index low to the
1910 for (high = var->n_var_parts; high > low; high--)
1911 var->var_part[high] = var->var_part[high - 1];
1914 var->var_part[pos].offset = offset;
1915 var->var_part[pos].loc_chain = NULL;
1916 var->var_part[pos].cur_loc = NULL;
1920 /* Delete the location from list. */
1922 for (node = var->var_part[pos].loc_chain; node; node = next)
1925 if ((GET_CODE (node->loc) == REG && GET_CODE (loc) == REG
1926 && REGNO (node->loc) == REGNO (loc))
1927 || rtx_equal_p (node->loc, loc))
1932 var->var_part[pos].loc_chain = next;
1933 pool_free (loc_chain_pool, node);
1940 /* Add the location to the beginning. */
1941 node = pool_alloc (loc_chain_pool);
1943 node->next = var->var_part[pos].loc_chain;
1944 var->var_part[pos].loc_chain = node;
1946 /* If no location was emitted do so. */
1947 if (var->var_part[pos].cur_loc == NULL)
1949 var->var_part[pos].cur_loc = loc;
1950 variable_was_changed (var, set->vars);
1954 /* Delete the part of variable's location from dataflow set SET. The variable
1955 part is specified by variable's declaration DECL and offset OFFSET and the
1956 part's location by LOC. */
1959 delete_variable_part (dataflow_set *set, rtx loc, tree decl,
1960 HOST_WIDE_INT offset)
1965 slot = htab_find_slot_with_hash (set->vars, decl, VARIABLE_HASH_VAL (decl),
1969 variable var = (variable) *slot;
1971 /* Find the location part. */
1973 high = var->n_var_parts;
1976 pos = (low + high) / 2;
1977 if (var->var_part[pos].offset < offset)
1984 if (pos < var->n_var_parts && var->var_part[pos].offset == offset)
1986 location_chain node, prev, next;
1989 /* Delete the location part. */
1991 for (node = var->var_part[pos].loc_chain; node; node = next)
1994 if ((GET_CODE (node->loc) == REG && GET_CODE (loc) == REG
1995 && REGNO (node->loc) == REGNO (loc))
1996 || rtx_equal_p (node->loc, loc))
2001 var->var_part[pos].loc_chain = next;
2002 pool_free (loc_chain_pool, node);
2009 /* If we have deleted the location which was last emitted
2010 we have to emit new location so add the variable to set
2011 of changed variables. */
2012 if (var->var_part[pos].cur_loc
2013 && ((GET_CODE (loc) == REG
2014 && GET_CODE (var->var_part[pos].cur_loc) == REG
2015 && REGNO (loc) == REGNO (var->var_part[pos].cur_loc))
2016 || rtx_equal_p (loc, var->var_part[pos].cur_loc)))
2019 if (var->var_part[pos].loc_chain)
2020 var->var_part[pos].cur_loc = var->var_part[pos].loc_chain->loc;
2025 if (var->var_part[pos].loc_chain == NULL)
2028 while (pos < var->n_var_parts)
2030 var->var_part[pos] = var->var_part[pos + 1];
2035 variable_was_changed (var, set->vars);
2040 /* Emit the NOTE_INSN_VAR_LOCATION for variable *VARP. DATA contains
2041 additional parameters: WHERE specifies whether the note shall be emitted
2042 before of after instruction INSN. */
2045 emit_note_insn_var_location (void **varp, void *data)
2047 variable var = *(variable *) varp;
2048 rtx insn = ((emit_note_data *)data)->insn;
2049 enum emit_note_where where = ((emit_note_data *)data)->where;
2053 HOST_WIDE_INT last_limit;
2054 tree type_size_unit;
2056 #ifdef ENABLE_CHECKING
2063 for (i = 0; i < var->n_var_parts; i++)
2065 if (last_limit < var->var_part[i].offset)
2071 = (var->var_part[i].offset
2072 + GET_MODE_SIZE (GET_MODE (var->var_part[i].loc_chain->loc)));
2074 type_size_unit = TYPE_SIZE_UNIT (TREE_TYPE (var->decl));
2075 if ((unsigned HOST_WIDE_INT) last_limit < TREE_INT_CST_LOW (type_size_unit))
2078 if (where == EMIT_NOTE_AFTER_INSN)
2079 note = emit_note_after (NOTE_INSN_VAR_LOCATION, insn);
2081 note = emit_note_before (NOTE_INSN_VAR_LOCATION, insn);
2085 NOTE_VAR_LOCATION (note) = gen_rtx_VAR_LOCATION (VOIDmode, var->decl,
2088 else if (var->n_var_parts == 1)
2091 = gen_rtx_EXPR_LIST (VOIDmode,
2092 var->var_part[0].loc_chain->loc,
2093 GEN_INT (var->var_part[0].offset));
2095 NOTE_VAR_LOCATION (note) = gen_rtx_VAR_LOCATION (VOIDmode, var->decl,
2098 else if (var->n_var_parts)
2100 rtx argp[MAX_VAR_PARTS];
2103 for (i = 0; i < var->n_var_parts; i++)
2104 argp[i] = gen_rtx_EXPR_LIST (VOIDmode, var->var_part[i].loc_chain->loc,
2105 GEN_INT (var->var_part[i].offset));
2106 parallel = gen_rtx_PARALLEL (VOIDmode,
2107 gen_rtvec_v (var->n_var_parts, argp));
2108 NOTE_VAR_LOCATION (note) = gen_rtx_VAR_LOCATION (VOIDmode, var->decl,
2112 htab_clear_slot (changed_variables, varp);
2114 /* When there are no location parts the variable has been already
2115 removed from hash table and a new empty variable was created.
2116 Free the empty variable. */
2117 if (var->n_var_parts == 0)
2119 pool_free (var_pool, var);
2122 /* Continue traversing the hash table. */
2126 /* Emit NOTE_INSN_VAR_LOCATION note for each variable from a chain
2127 CHANGED_VARIABLES and delete this chain. WHERE specifies whether the notes
2128 shall be emitted before of after instruction INSN. */
2131 emit_notes_for_changes (rtx insn, enum emit_note_where where)
2133 emit_note_data data;
2137 htab_traverse (changed_variables, emit_note_insn_var_location, &data);
2140 /* Add variable *SLOT to the chain CHANGED_VARIABLES if it differs from the
2141 same variable in hash table DATA or is not there at all. */
2144 emit_notes_for_differences_1 (void **slot, void *data)
2146 htab_t new_vars = (htab_t) data;
2147 variable old_var, new_var;
2149 old_var = *(variable *) slot;
2150 new_var = (variable) htab_find_with_hash (new_vars, old_var->decl,
2151 VARIABLE_HASH_VAL (old_var->decl));
2155 /* Variable has disappeared. */
2158 empty_var = pool_alloc (var_pool);
2159 empty_var->decl = old_var->decl;
2160 empty_var->n_var_parts = 0;
2161 variable_was_changed (empty_var, NULL);
2163 else if (variable_different_p (old_var, new_var))
2165 variable_was_changed (new_var, NULL);
2168 /* Continue traversing the hash table. */
2172 /* Add variable *SLOT to the chain CHANGED_VARIABLES if it is not in hash
2176 emit_notes_for_differences_2 (void **slot, void *data)
2178 htab_t old_vars = (htab_t) data;
2179 variable old_var, new_var;
2181 new_var = *(variable *) slot;
2182 old_var = (variable) htab_find_with_hash (old_vars, new_var->decl,
2183 VARIABLE_HASH_VAL (new_var->decl));
2186 /* Variable has appeared. */
2187 variable_was_changed (new_var, NULL);
2190 /* Continue traversing the hash table. */
2194 /* Emit notes before INSN for differences between dataflow sets OLD_SET and
2198 emit_notes_for_differences (rtx insn, dataflow_set *old_set,
2199 dataflow_set *new_set)
2201 htab_traverse (old_set->vars, emit_notes_for_differences_1, new_set->vars);
2202 htab_traverse (new_set->vars, emit_notes_for_differences_2, old_set->vars);
2203 emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
2206 /* Emit the notes for changes of location parts in the basic block BB. */
2209 emit_notes_in_bb (basic_block bb)
2214 dataflow_set_init (&set, htab_elements (VTI (bb)->in.vars) + 3);
2215 dataflow_set_copy (&set, &VTI (bb)->in);
2217 for (i = 0; i < VTI (bb)->n_mos; i++)
2219 rtx insn = VTI (bb)->mos[i].insn;
2221 switch (VTI (bb)->mos[i].type)
2227 for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
2228 if (TEST_HARD_REG_BIT (call_used_reg_set, r))
2230 var_regno_delete (&set, r);
2232 emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
2239 rtx loc = VTI (bb)->mos[i].u.loc;
2241 if (GET_CODE (loc) == REG)
2242 var_reg_delete_and_set (&set, loc);
2244 var_mem_delete_and_set (&set, loc);
2246 if (VTI (bb)->mos[i].type == MO_USE)
2247 emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
2249 emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
2256 rtx loc = VTI (bb)->mos[i].u.loc;
2258 if (GET_CODE (loc) == REG)
2259 var_reg_delete (&set, loc);
2261 var_mem_delete (&set, loc);
2263 if (VTI (bb)->mos[i].type == MO_USE_NO_VAR)
2264 emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
2266 emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
2274 set.stack_adjust += VTI (bb)->mos[i].u.adjust;
2275 base = gen_rtx_MEM (Pmode,
2276 gen_rtx_PLUS (Pmode, stack_pointer_rtx,
2277 GEN_INT (set.stack_adjust)));
2278 set_frame_base_location (&set, base);
2279 emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
2284 dataflow_set_destroy (&set);
2287 /* Emit notes for the whole function. */
2290 vt_emit_notes (void)
2293 dataflow_set *last_out;
2296 #ifdef ENABLE_CHECKING
2297 if (htab_elements (changed_variables))
2301 /* Enable emitting notes by functions (mainly by set_variable_part and
2302 delete_variable_part). */
2305 dataflow_set_init (&empty, 7);
2310 /* Emit the notes for changes of variable locations between two
2311 subsequent basic blocks. */
2312 emit_notes_for_differences (BB_HEAD (bb), last_out, &VTI (bb)->in);
2314 /* Emit the notes for the changes in the basic block itself. */
2315 emit_notes_in_bb (bb);
2317 last_out = &VTI (bb)->out;
2319 dataflow_set_destroy (&empty);
2323 /* If there is a declaration and offset associated with register/memory RTL
2324 assign declaration to *DECLP and offset to *OFFSETP, and return true. */
2327 vt_get_decl_and_offset (rtx rtl, tree *declp, HOST_WIDE_INT *offsetp)
2329 if (GET_CODE (rtl) == REG)
2331 if (REG_ATTRS (rtl))
2333 *declp = REG_EXPR (rtl);
2334 *offsetp = REG_OFFSET (rtl);
2338 else if (GET_CODE (rtl) == MEM)
2340 if (MEM_ATTRS (rtl))
2342 *declp = MEM_EXPR (rtl);
2343 *offsetp = MEM_OFFSET (rtl) ? INTVAL (MEM_OFFSET (rtl)) : 0;
2350 /* Insert function parameters to IN and OUT sets of ENTRY_BLOCK. */
2353 vt_add_function_parameters (void)
2356 HOST_WIDE_INT stack_adjust = 0;
2358 if (!frame_pointer_needed)
2359 stack_adjust = prologue_stack_adjust ();
2361 for (parm = DECL_ARGUMENTS (current_function_decl);
2362 parm; parm = TREE_CHAIN (parm))
2364 rtx decl_rtl = DECL_RTL_IF_SET (parm);
2365 rtx incoming = DECL_INCOMING_RTL (parm);
2367 HOST_WIDE_INT offset;
2368 dataflow_set *in, *out;
2370 if (TREE_CODE (parm) != PARM_DECL)
2373 if (!DECL_NAME (parm))
2376 if (!decl_rtl || !incoming)
2379 if (GET_MODE (decl_rtl) == BLKmode || GET_MODE (incoming) == BLKmode)
2382 if (!vt_get_decl_and_offset (incoming, &decl, &offset))
2383 if (!vt_get_decl_and_offset (decl_rtl, &decl, &offset))
2389 #ifdef ENABLE_CHECKING
2394 incoming = eliminate_regs (incoming, 0, NULL_RTX);
2395 if (!frame_pointer_needed && GET_CODE (incoming) == MEM)
2396 incoming = adjust_stack_reference (incoming, -stack_adjust);
2397 in = &VTI (ENTRY_BLOCK_PTR)->in;
2398 out = &VTI (ENTRY_BLOCK_PTR)->out;
2400 if (GET_CODE (incoming) == REG)
2402 #ifdef ENABLE_CHECKING
2403 if (REGNO (incoming) >= FIRST_PSEUDO_REGISTER)
2406 attrs_list_insert (&in->regs[REGNO (incoming)],
2407 parm, offset, incoming);
2408 attrs_list_insert (&out->regs[REGNO (incoming)],
2409 parm, offset, incoming);
2410 set_variable_part (in, incoming, parm, offset);
2411 set_variable_part (out, incoming, parm, offset);
2413 else if (GET_CODE (incoming) == MEM)
2415 set_variable_part (in, incoming, parm, offset);
2416 set_variable_part (out, incoming, parm, offset);
2421 /* Allocate and initialize the data structures for variable tracking
2422 and parse the RTL to get the micro operations. */
2425 vt_initialize (void)
2429 alloc_aux_for_blocks (sizeof (struct variable_tracking_info_def));
2434 HOST_WIDE_INT pre, post;
2436 /* Count the number of micro operations. */
2437 VTI (bb)->n_mos = 0;
2438 for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
2439 insn = NEXT_INSN (insn))
2443 if (!frame_pointer_needed)
2445 insn_stack_adjust_offset_pre_post (insn, &pre, &post);
2451 note_uses (&PATTERN (insn), count_uses_1, insn);
2452 note_stores (PATTERN (insn), count_stores, insn);
2453 if (GET_CODE (insn) == CALL_INSN)
2458 /* Add the micro-operations to the array. */
2459 VTI (bb)->mos = xmalloc (VTI (bb)->n_mos
2460 * sizeof (struct micro_operation_def));
2461 VTI (bb)->n_mos = 0;
2462 for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
2463 insn = NEXT_INSN (insn))
2469 if (!frame_pointer_needed)
2471 insn_stack_adjust_offset_pre_post (insn, &pre, &post);
2474 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
2476 mo->type = MO_ADJUST;
2482 n1 = VTI (bb)->n_mos;
2483 note_uses (&PATTERN (insn), add_uses_1, insn);
2484 n2 = VTI (bb)->n_mos - 1;
2486 /* Order the MO_USEs to be before MO_USE_NO_VARs. */
2489 while (n1 < n2 && VTI (bb)->mos[n1].type == MO_USE)
2491 while (n1 < n2 && VTI (bb)->mos[n2].type == MO_USE_NO_VAR)
2497 sw = VTI (bb)->mos[n1];
2498 VTI (bb)->mos[n1] = VTI (bb)->mos[n2];
2499 VTI (bb)->mos[n2] = sw;
2503 if (GET_CODE (insn) == CALL_INSN)
2505 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
2511 n1 = VTI (bb)->n_mos;
2512 note_stores (PATTERN (insn), add_stores, insn);
2513 n2 = VTI (bb)->n_mos - 1;
2515 /* Order the MO_SETs to be before MO_CLOBBERs. */
2518 while (n1 < n2 && VTI (bb)->mos[n1].type == MO_SET)
2520 while (n1 < n2 && VTI (bb)->mos[n2].type == MO_CLOBBER)
2526 sw = VTI (bb)->mos[n1];
2527 VTI (bb)->mos[n1] = VTI (bb)->mos[n2];
2528 VTI (bb)->mos[n2] = sw;
2532 if (!frame_pointer_needed && post)
2534 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
2536 mo->type = MO_ADJUST;
2537 mo->u.adjust = post;
2544 /* Init the IN and OUT sets. */
2547 VTI (bb)->visited = false;
2548 dataflow_set_init (&VTI (bb)->in, 7);
2549 dataflow_set_init (&VTI (bb)->out, 7);
2552 attrs_pool = create_alloc_pool ("attrs_def pool",
2553 sizeof (struct attrs_def), 1024);
2554 var_pool = create_alloc_pool ("variable_def pool",
2555 sizeof (struct variable_def), 64);
2556 loc_chain_pool = create_alloc_pool ("location_chain_def pool",
2557 sizeof (struct location_chain_def),
2559 changed_variables = htab_create (10, variable_htab_hash, variable_htab_eq,
2561 vt_add_function_parameters ();
2563 if (!frame_pointer_needed)
2567 /* Create fake variable for tracking stack pointer changes. */
2568 frame_base_decl = make_node (VAR_DECL);
2569 DECL_NAME (frame_base_decl) = get_identifier ("___frame_base_decl");
2570 TREE_TYPE (frame_base_decl) = char_type_node;
2571 DECL_ARTIFICIAL (frame_base_decl) = 1;
2573 /* Set its initial "location". */
2574 base = gen_rtx_MEM (Pmode, stack_pointer_rtx);
2575 set_variable_part (&VTI (ENTRY_BLOCK_PTR)->in, base, frame_base_decl, 0);
2576 set_variable_part (&VTI (ENTRY_BLOCK_PTR)->out, base, frame_base_decl, 0);
2580 frame_base_decl = NULL;
2584 /* Free the data structures needed for variable tracking. */
2593 free (VTI (bb)->mos);
2598 dataflow_set_destroy (&VTI (bb)->in);
2599 dataflow_set_destroy (&VTI (bb)->out);
2601 free_aux_for_blocks ();
2602 free_alloc_pool (attrs_pool);
2603 free_alloc_pool (var_pool);
2604 free_alloc_pool (loc_chain_pool);
2605 htab_delete (changed_variables);
2608 /* The entry point to variable tracking pass. */
2611 variable_tracking_main (void)
2613 if (n_basic_blocks > 500 && n_edges / n_basic_blocks >= 20)
2616 mark_dfs_back_edges ();
2618 if (!frame_pointer_needed)
2620 if (!vt_stack_adjustments ())
2627 vt_find_locations ();
2632 dump_dataflow_sets ();
2633 dump_flow_info (rtl_dump_file);