1 /* Variable tracking routines for the GNU compiler.
2 Copyright (C) 2002, 2003, 2004, 2005 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, 51 Franklin Street, Fifth Floor, 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"
108 #include "tree-pass.h"
110 /* Type of micro operation. */
111 enum micro_operation_type
113 MO_USE, /* Use location (REG or MEM). */
114 MO_USE_NO_VAR,/* Use location which is not associated with a variable
115 or the variable is not trackable. */
116 MO_SET, /* Set location. */
117 MO_COPY, /* Copy the same portion of a variable from one
118 location to another. */
119 MO_CLOBBER, /* Clobber location. */
120 MO_CALL, /* Call insn. */
121 MO_ADJUST /* Adjust stack pointer. */
124 /* Where shall the note be emitted? BEFORE or AFTER the instruction. */
127 EMIT_NOTE_BEFORE_INSN,
131 /* Structure holding information about micro operation. */
132 typedef struct micro_operation_def
134 /* Type of micro operation. */
135 enum micro_operation_type type;
141 /* Stack adjustment. */
142 HOST_WIDE_INT adjust;
145 /* The instruction which the micro operation is in, for MO_USE,
146 MO_USE_NO_VAR, MO_CALL and MO_ADJUST, or the subsequent
147 instruction or note in the original flow (before any var-tracking
148 notes are inserted, to simplify emission of notes), for MO_SET
153 /* Structure for passing some other parameters to function
154 emit_note_insn_var_location. */
155 typedef struct emit_note_data_def
157 /* The instruction which the note will be emitted before/after. */
160 /* Where the note will be emitted (before/after insn)? */
161 enum emit_note_where where;
164 /* Description of location of a part of a variable. The content of a physical
165 register is described by a chain of these structures.
166 The chains are pretty short (usually 1 or 2 elements) and thus
167 chain is the best data structure. */
168 typedef struct attrs_def
170 /* Pointer to next member of the list. */
171 struct attrs_def *next;
173 /* The rtx of register. */
176 /* The declaration corresponding to LOC. */
179 /* Offset from start of DECL. */
180 HOST_WIDE_INT offset;
183 /* Structure holding the IN or OUT set for a basic block. */
184 typedef struct dataflow_set_def
186 /* Adjustment of stack offset. */
187 HOST_WIDE_INT stack_adjust;
189 /* Attributes for registers (lists of attrs). */
190 attrs regs[FIRST_PSEUDO_REGISTER];
192 /* Variable locations. */
196 /* The structure (one for each basic block) containing the information
197 needed for variable tracking. */
198 typedef struct variable_tracking_info_def
200 /* Number of micro operations stored in the MOS array. */
203 /* The array of micro operations. */
204 micro_operation *mos;
206 /* The IN and OUT set for dataflow analysis. */
210 /* Has the block been visited in DFS? */
212 } *variable_tracking_info;
214 /* Structure for chaining the locations. */
215 typedef struct location_chain_def
217 /* Next element in the chain. */
218 struct location_chain_def *next;
220 /* The location (REG or MEM). */
223 /* The "value" stored in this location. */
227 enum var_init_status init;
230 /* Structure describing one part of variable. */
231 typedef struct variable_part_def
233 /* Chain of locations of the part. */
234 location_chain loc_chain;
236 /* Location which was last emitted to location list. */
239 /* The offset in the variable. */
240 HOST_WIDE_INT offset;
243 /* Maximum number of location parts. */
244 #define MAX_VAR_PARTS 16
246 /* Structure describing where the variable is located. */
247 typedef struct variable_def
249 /* The declaration of the variable. */
252 /* Reference count. */
255 /* Number of variable parts. */
258 /* The variable parts. */
259 variable_part var_part[MAX_VAR_PARTS];
262 /* Hash function for DECL for VARIABLE_HTAB. */
263 #define VARIABLE_HASH_VAL(decl) (DECL_UID (decl))
265 /* Pointer to the BB's information specific to variable tracking pass. */
266 #define VTI(BB) ((variable_tracking_info) (BB)->aux)
268 /* Alloc pool for struct attrs_def. */
269 static alloc_pool attrs_pool;
271 /* Alloc pool for struct variable_def. */
272 static alloc_pool var_pool;
274 /* Alloc pool for struct location_chain_def. */
275 static alloc_pool loc_chain_pool;
277 /* Changed variables, notes will be emitted for them. */
278 static htab_t changed_variables;
280 /* Shall notes be emitted? */
281 static bool emit_notes;
283 /* Local function prototypes. */
284 static void stack_adjust_offset_pre_post (rtx, HOST_WIDE_INT *,
286 static void insn_stack_adjust_offset_pre_post (rtx, HOST_WIDE_INT *,
288 static void bb_stack_adjust_offset (basic_block);
289 static bool vt_stack_adjustments (void);
290 static rtx adjust_stack_reference (rtx, HOST_WIDE_INT);
291 static hashval_t variable_htab_hash (const void *);
292 static int variable_htab_eq (const void *, const void *);
293 static void variable_htab_free (void *);
295 static void init_attrs_list_set (attrs *);
296 static void attrs_list_clear (attrs *);
297 static attrs attrs_list_member (attrs, tree, HOST_WIDE_INT);
298 static void attrs_list_insert (attrs *, tree, HOST_WIDE_INT, rtx);
299 static void attrs_list_copy (attrs *, attrs);
300 static void attrs_list_union (attrs *, attrs);
302 static void vars_clear (htab_t);
303 static variable unshare_variable (dataflow_set *set, variable var,
304 enum var_init_status);
305 static int vars_copy_1 (void **, void *);
306 static void vars_copy (htab_t, htab_t);
307 static tree var_debug_decl (tree);
308 static void var_reg_set (dataflow_set *, rtx, enum var_init_status, rtx);
309 static void var_reg_delete_and_set (dataflow_set *, rtx, bool,
310 enum var_init_status, rtx);
311 static void var_reg_delete (dataflow_set *, rtx, bool);
312 static void var_regno_delete (dataflow_set *, int);
313 static void var_mem_set (dataflow_set *, rtx, enum var_init_status, rtx);
314 static void var_mem_delete_and_set (dataflow_set *, rtx, bool,
315 enum var_init_status, rtx);
316 static void var_mem_delete (dataflow_set *, rtx, bool);
318 static void dataflow_set_init (dataflow_set *, int);
319 static void dataflow_set_clear (dataflow_set *);
320 static void dataflow_set_copy (dataflow_set *, dataflow_set *);
321 static int variable_union_info_cmp_pos (const void *, const void *);
322 static int variable_union (void **, void *);
323 static void dataflow_set_union (dataflow_set *, dataflow_set *);
324 static bool variable_part_different_p (variable_part *, variable_part *);
325 static bool variable_different_p (variable, variable, bool);
326 static int dataflow_set_different_1 (void **, void *);
327 static int dataflow_set_different_2 (void **, void *);
328 static bool dataflow_set_different (dataflow_set *, dataflow_set *);
329 static void dataflow_set_destroy (dataflow_set *);
331 static bool contains_symbol_ref (rtx);
332 static bool track_expr_p (tree);
333 static bool same_variable_part_p (rtx, tree, HOST_WIDE_INT);
334 static int count_uses (rtx *, void *);
335 static void count_uses_1 (rtx *, void *);
336 static void count_stores (rtx, rtx, void *);
337 static int add_uses (rtx *, void *);
338 static void add_uses_1 (rtx *, void *);
339 static void add_stores (rtx, rtx, void *);
340 static bool compute_bb_dataflow (basic_block);
341 static void vt_find_locations (void);
343 static void dump_attrs_list (attrs);
344 static int dump_variable (void **, void *);
345 static void dump_vars (htab_t);
346 static void dump_dataflow_set (dataflow_set *);
347 static void dump_dataflow_sets (void);
349 static void variable_was_changed (variable, htab_t);
350 static void set_variable_part (dataflow_set *, rtx, tree, HOST_WIDE_INT,
351 enum var_init_status, rtx);
352 static void clobber_variable_part (dataflow_set *, rtx, tree, HOST_WIDE_INT,
354 static void delete_variable_part (dataflow_set *, rtx, tree, HOST_WIDE_INT);
355 static int emit_note_insn_var_location (void **, void *);
356 static void emit_notes_for_changes (rtx, enum emit_note_where);
357 static int emit_notes_for_differences_1 (void **, void *);
358 static int emit_notes_for_differences_2 (void **, void *);
359 static void emit_notes_for_differences (rtx, dataflow_set *, dataflow_set *);
360 static void emit_notes_in_bb (basic_block);
361 static void vt_emit_notes (void);
363 static bool vt_get_decl_and_offset (rtx, tree *, HOST_WIDE_INT *);
364 static void vt_add_function_parameters (void);
365 static void vt_initialize (void);
366 static void vt_finalize (void);
368 /* Given a SET, calculate the amount of stack adjustment it contains
369 PRE- and POST-modifying stack pointer.
370 This function is similar to stack_adjust_offset. */
373 stack_adjust_offset_pre_post (rtx pattern, HOST_WIDE_INT *pre,
376 rtx src = SET_SRC (pattern);
377 rtx dest = SET_DEST (pattern);
380 if (dest == stack_pointer_rtx)
382 /* (set (reg sp) (plus (reg sp) (const_int))) */
383 code = GET_CODE (src);
384 if (! (code == PLUS || code == MINUS)
385 || XEXP (src, 0) != stack_pointer_rtx
386 || GET_CODE (XEXP (src, 1)) != CONST_INT)
390 *post += INTVAL (XEXP (src, 1));
392 *post -= INTVAL (XEXP (src, 1));
394 else if (MEM_P (dest))
396 /* (set (mem (pre_dec (reg sp))) (foo)) */
397 src = XEXP (dest, 0);
398 code = GET_CODE (src);
404 if (XEXP (src, 0) == stack_pointer_rtx)
406 rtx val = XEXP (XEXP (src, 1), 1);
407 /* We handle only adjustments by constant amount. */
408 gcc_assert (GET_CODE (XEXP (src, 1)) == PLUS &&
409 GET_CODE (val) == CONST_INT);
411 if (code == PRE_MODIFY)
412 *pre -= INTVAL (val);
414 *post -= INTVAL (val);
420 if (XEXP (src, 0) == stack_pointer_rtx)
422 *pre += GET_MODE_SIZE (GET_MODE (dest));
428 if (XEXP (src, 0) == stack_pointer_rtx)
430 *post += GET_MODE_SIZE (GET_MODE (dest));
436 if (XEXP (src, 0) == stack_pointer_rtx)
438 *pre -= GET_MODE_SIZE (GET_MODE (dest));
444 if (XEXP (src, 0) == stack_pointer_rtx)
446 *post -= GET_MODE_SIZE (GET_MODE (dest));
457 /* Given an INSN, calculate the amount of stack adjustment it contains
458 PRE- and POST-modifying stack pointer. */
461 insn_stack_adjust_offset_pre_post (rtx insn, HOST_WIDE_INT *pre,
467 if (GET_CODE (PATTERN (insn)) == SET)
468 stack_adjust_offset_pre_post (PATTERN (insn), pre, post);
469 else if (GET_CODE (PATTERN (insn)) == PARALLEL
470 || GET_CODE (PATTERN (insn)) == SEQUENCE)
474 /* There may be stack adjustments inside compound insns. Search
476 for ( i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
477 if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET)
478 stack_adjust_offset_pre_post (XVECEXP (PATTERN (insn), 0, i),
483 /* Compute stack adjustment in basic block BB. */
486 bb_stack_adjust_offset (basic_block bb)
488 HOST_WIDE_INT offset;
491 offset = VTI (bb)->in.stack_adjust;
492 for (i = 0; i < VTI (bb)->n_mos; i++)
494 if (VTI (bb)->mos[i].type == MO_ADJUST)
495 offset += VTI (bb)->mos[i].u.adjust;
496 else if (VTI (bb)->mos[i].type != MO_CALL)
498 if (MEM_P (VTI (bb)->mos[i].u.loc))
500 VTI (bb)->mos[i].u.loc
501 = adjust_stack_reference (VTI (bb)->mos[i].u.loc, -offset);
505 VTI (bb)->out.stack_adjust = offset;
508 /* Compute stack adjustments for all blocks by traversing DFS tree.
509 Return true when the adjustments on all incoming edges are consistent.
510 Heavily borrowed from pre_and_rev_post_order_compute. */
513 vt_stack_adjustments (void)
515 edge_iterator *stack;
518 /* Initialize entry block. */
519 VTI (ENTRY_BLOCK_PTR)->visited = true;
520 VTI (ENTRY_BLOCK_PTR)->out.stack_adjust = INCOMING_FRAME_SP_OFFSET;
522 /* Allocate stack for back-tracking up CFG. */
523 stack = XNEWVEC (edge_iterator, n_basic_blocks + 1);
526 /* Push the first edge on to the stack. */
527 stack[sp++] = ei_start (ENTRY_BLOCK_PTR->succs);
535 /* Look at the edge on the top of the stack. */
537 src = ei_edge (ei)->src;
538 dest = ei_edge (ei)->dest;
540 /* Check if the edge destination has been visited yet. */
541 if (!VTI (dest)->visited)
543 VTI (dest)->visited = true;
544 VTI (dest)->in.stack_adjust = VTI (src)->out.stack_adjust;
545 bb_stack_adjust_offset (dest);
547 if (EDGE_COUNT (dest->succs) > 0)
548 /* Since the DEST node has been visited for the first
549 time, check its successors. */
550 stack[sp++] = ei_start (dest->succs);
554 /* Check whether the adjustments on the edges are the same. */
555 if (VTI (dest)->in.stack_adjust != VTI (src)->out.stack_adjust)
561 if (! ei_one_before_end_p (ei))
562 /* Go to the next edge. */
563 ei_next (&stack[sp - 1]);
565 /* Return to previous level if there are no more edges. */
574 /* Adjust stack reference MEM by ADJUSTMENT bytes and make it relative
575 to the argument pointer. Return the new rtx. */
578 adjust_stack_reference (rtx mem, HOST_WIDE_INT adjustment)
582 #ifdef FRAME_POINTER_CFA_OFFSET
583 adjustment -= FRAME_POINTER_CFA_OFFSET (current_function_decl);
584 cfa = plus_constant (frame_pointer_rtx, adjustment);
586 adjustment -= ARG_POINTER_CFA_OFFSET (current_function_decl);
587 cfa = plus_constant (arg_pointer_rtx, adjustment);
590 addr = replace_rtx (copy_rtx (XEXP (mem, 0)), stack_pointer_rtx, cfa);
591 tmp = simplify_rtx (addr);
595 return replace_equiv_address_nv (mem, addr);
598 /* The hash function for variable_htab, computes the hash value
599 from the declaration of variable X. */
602 variable_htab_hash (const void *x)
604 const variable v = (const variable) x;
606 return (VARIABLE_HASH_VAL (v->decl));
609 /* Compare the declaration of variable X with declaration Y. */
612 variable_htab_eq (const void *x, const void *y)
614 const variable v = (const variable) x;
615 const tree decl = (const tree) y;
617 return (VARIABLE_HASH_VAL (v->decl) == VARIABLE_HASH_VAL (decl));
620 /* Free the element of VARIABLE_HTAB (its type is struct variable_def). */
623 variable_htab_free (void *elem)
626 variable var = (variable) elem;
627 location_chain node, next;
629 gcc_assert (var->refcount > 0);
632 if (var->refcount > 0)
635 for (i = 0; i < var->n_var_parts; i++)
637 for (node = var->var_part[i].loc_chain; node; node = next)
640 pool_free (loc_chain_pool, node);
642 var->var_part[i].loc_chain = NULL;
644 pool_free (var_pool, var);
647 /* Initialize the set (array) SET of attrs to empty lists. */
650 init_attrs_list_set (attrs *set)
654 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
658 /* Make the list *LISTP empty. */
661 attrs_list_clear (attrs *listp)
665 for (list = *listp; list; list = next)
668 pool_free (attrs_pool, list);
673 /* Return true if the pair of DECL and OFFSET is the member of the LIST. */
676 attrs_list_member (attrs list, tree decl, HOST_WIDE_INT offset)
678 for (; list; list = list->next)
679 if (list->decl == decl && list->offset == offset)
684 /* Insert the triplet DECL, OFFSET, LOC to the list *LISTP. */
687 attrs_list_insert (attrs *listp, tree decl, HOST_WIDE_INT offset, rtx loc)
691 list = pool_alloc (attrs_pool);
694 list->offset = offset;
699 /* Copy all nodes from SRC and create a list *DSTP of the copies. */
702 attrs_list_copy (attrs *dstp, attrs src)
706 attrs_list_clear (dstp);
707 for (; src; src = src->next)
709 n = pool_alloc (attrs_pool);
712 n->offset = src->offset;
718 /* Add all nodes from SRC which are not in *DSTP to *DSTP. */
721 attrs_list_union (attrs *dstp, attrs src)
723 for (; src; src = src->next)
725 if (!attrs_list_member (*dstp, src->decl, src->offset))
726 attrs_list_insert (dstp, src->decl, src->offset, src->loc);
730 /* Delete all variables from hash table VARS. */
733 vars_clear (htab_t vars)
738 /* Return a copy of a variable VAR and insert it to dataflow set SET. */
741 unshare_variable (dataflow_set *set, variable var,
742 enum var_init_status initialized)
748 new_var = pool_alloc (var_pool);
749 new_var->decl = var->decl;
750 new_var->refcount = 1;
752 new_var->n_var_parts = var->n_var_parts;
754 for (i = 0; i < var->n_var_parts; i++)
757 location_chain *nextp;
759 new_var->var_part[i].offset = var->var_part[i].offset;
760 nextp = &new_var->var_part[i].loc_chain;
761 for (node = var->var_part[i].loc_chain; node; node = node->next)
763 location_chain new_lc;
765 new_lc = pool_alloc (loc_chain_pool);
767 if (node->init > initialized)
768 new_lc->init = node->init;
770 new_lc->init = initialized;
771 if (node->set_src && !(MEM_P (node->set_src)))
772 new_lc->set_src = node->set_src;
774 new_lc->set_src = NULL;
775 new_lc->loc = node->loc;
778 nextp = &new_lc->next;
781 /* We are at the basic block boundary when copying variable description
782 so set the CUR_LOC to be the first element of the chain. */
783 if (new_var->var_part[i].loc_chain)
784 new_var->var_part[i].cur_loc = new_var->var_part[i].loc_chain->loc;
786 new_var->var_part[i].cur_loc = NULL;
789 slot = htab_find_slot_with_hash (set->vars, new_var->decl,
790 VARIABLE_HASH_VAL (new_var->decl),
796 /* Add a variable from *SLOT to hash table DATA and increase its reference
800 vars_copy_1 (void **slot, void *data)
802 htab_t dst = (htab_t) data;
805 src = *(variable *) slot;
808 dstp = (variable *) htab_find_slot_with_hash (dst, src->decl,
809 VARIABLE_HASH_VAL (src->decl),
813 /* Continue traversing the hash table. */
817 /* Copy all variables from hash table SRC to hash table DST. */
820 vars_copy (htab_t dst, htab_t src)
823 htab_traverse (src, vars_copy_1, dst);
826 /* Map a decl to its main debug decl. */
829 var_debug_decl (tree decl)
831 if (decl && DECL_P (decl)
832 && DECL_DEBUG_EXPR_IS_FROM (decl) && DECL_DEBUG_EXPR (decl)
833 && DECL_P (DECL_DEBUG_EXPR (decl)))
834 decl = DECL_DEBUG_EXPR (decl);
839 /* Set the register to contain REG_EXPR (LOC), REG_OFFSET (LOC). */
842 var_reg_set (dataflow_set *set, rtx loc, enum var_init_status initialized,
845 tree decl = REG_EXPR (loc);
846 HOST_WIDE_INT offset = REG_OFFSET (loc);
849 decl = var_debug_decl (decl);
851 for (node = set->regs[REGNO (loc)]; node; node = node->next)
852 if (node->decl == decl && node->offset == offset)
855 attrs_list_insert (&set->regs[REGNO (loc)], decl, offset, loc);
856 set_variable_part (set, loc, decl, offset, initialized, set_src);
860 get_init_value (dataflow_set *set, rtx loc, tree decl)
865 int ret_val = VAR_INIT_STATUS_UNKNOWN;
867 if (! flag_var_tracking_uninit)
868 return VAR_INIT_STATUS_INITIALIZED;
870 slot = htab_find_slot_with_hash (set->vars, decl, VARIABLE_HASH_VAL (decl),
874 var = * (variable *) slot;
875 for (i = 0; i < var->n_var_parts && ret_val == VAR_INIT_STATUS_UNKNOWN; i++)
877 location_chain nextp;
878 for (nextp = var->var_part[i].loc_chain; nextp; nextp = nextp->next)
879 if (rtx_equal_p (nextp->loc, loc))
881 ret_val = nextp->init;
890 /* Delete current content of register LOC in dataflow set SET and set
891 the register to contain REG_EXPR (LOC), REG_OFFSET (LOC). If
892 MODIFY is true, any other live copies of the same variable part are
893 also deleted from the dataflow set, otherwise the variable part is
894 assumed to be copied from another location holding the same
898 var_reg_delete_and_set (dataflow_set *set, rtx loc, bool modify,
899 enum var_init_status initialized, rtx set_src)
901 tree decl = REG_EXPR (loc);
902 HOST_WIDE_INT offset = REG_OFFSET (loc);
906 decl = var_debug_decl (decl);
908 if (initialized == VAR_INIT_STATUS_UNKNOWN)
909 initialized = get_init_value (set, loc, decl);
911 nextp = &set->regs[REGNO (loc)];
912 for (node = *nextp; node; node = next)
915 if (node->decl != decl || node->offset != offset)
917 delete_variable_part (set, node->loc, node->decl, node->offset);
918 pool_free (attrs_pool, node);
928 clobber_variable_part (set, loc, decl, offset, set_src);
929 var_reg_set (set, loc, initialized, set_src);
932 /* Delete current content of register LOC in dataflow set SET. If
933 CLOBBER is true, also delete any other live copies of the same
937 var_reg_delete (dataflow_set *set, rtx loc, bool clobber)
939 attrs *reg = &set->regs[REGNO (loc)];
944 tree decl = REG_EXPR (loc);
945 HOST_WIDE_INT offset = REG_OFFSET (loc);
947 decl = var_debug_decl (decl);
949 clobber_variable_part (set, NULL, decl, offset, NULL);
952 for (node = *reg; node; node = next)
955 delete_variable_part (set, node->loc, node->decl, node->offset);
956 pool_free (attrs_pool, node);
961 /* Delete content of register with number REGNO in dataflow set SET. */
964 var_regno_delete (dataflow_set *set, int regno)
966 attrs *reg = &set->regs[regno];
969 for (node = *reg; node; node = next)
972 delete_variable_part (set, node->loc, node->decl, node->offset);
973 pool_free (attrs_pool, node);
978 /* Set the location part of variable MEM_EXPR (LOC) in dataflow set
980 Adjust the address first if it is stack pointer based. */
983 var_mem_set (dataflow_set *set, rtx loc, enum var_init_status initialized,
986 tree decl = MEM_EXPR (loc);
987 HOST_WIDE_INT offset = MEM_OFFSET (loc) ? INTVAL (MEM_OFFSET (loc)) : 0;
989 decl = var_debug_decl (decl);
991 set_variable_part (set, loc, decl, offset, initialized, set_src);
994 /* Delete and set the location part of variable MEM_EXPR (LOC) in
995 dataflow set SET to LOC. If MODIFY is true, any other live copies
996 of the same variable part are also deleted from the dataflow set,
997 otherwise the variable part is assumed to be copied from another
998 location holding the same part.
999 Adjust the address first if it is stack pointer based. */
1002 var_mem_delete_and_set (dataflow_set *set, rtx loc, bool modify,
1003 enum var_init_status initialized, rtx set_src)
1005 tree decl = MEM_EXPR (loc);
1006 HOST_WIDE_INT offset = MEM_OFFSET (loc) ? INTVAL (MEM_OFFSET (loc)) : 0;
1008 decl = var_debug_decl (decl);
1010 if (initialized == VAR_INIT_STATUS_UNKNOWN)
1011 initialized = get_init_value (set, loc, decl);
1014 clobber_variable_part (set, NULL, decl, offset, set_src);
1015 var_mem_set (set, loc, initialized, set_src);
1018 /* Delete the location part LOC from dataflow set SET. If CLOBBER is
1019 true, also delete any other live copies of the same variable part.
1020 Adjust the address first if it is stack pointer based. */
1023 var_mem_delete (dataflow_set *set, rtx loc, bool clobber)
1025 tree decl = MEM_EXPR (loc);
1026 HOST_WIDE_INT offset = MEM_OFFSET (loc) ? INTVAL (MEM_OFFSET (loc)) : 0;
1028 decl = var_debug_decl (decl);
1030 clobber_variable_part (set, NULL, decl, offset, NULL);
1031 delete_variable_part (set, loc, decl, offset);
1034 /* Initialize dataflow set SET to be empty.
1035 VARS_SIZE is the initial size of hash table VARS. */
1038 dataflow_set_init (dataflow_set *set, int vars_size)
1040 init_attrs_list_set (set->regs);
1041 set->vars = htab_create (vars_size, variable_htab_hash, variable_htab_eq,
1042 variable_htab_free);
1043 set->stack_adjust = 0;
1046 /* Delete the contents of dataflow set SET. */
1049 dataflow_set_clear (dataflow_set *set)
1053 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1054 attrs_list_clear (&set->regs[i]);
1056 vars_clear (set->vars);
1059 /* Copy the contents of dataflow set SRC to DST. */
1062 dataflow_set_copy (dataflow_set *dst, dataflow_set *src)
1066 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1067 attrs_list_copy (&dst->regs[i], src->regs[i]);
1069 vars_copy (dst->vars, src->vars);
1070 dst->stack_adjust = src->stack_adjust;
1073 /* Information for merging lists of locations for a given offset of variable.
1075 struct variable_union_info
1077 /* Node of the location chain. */
1080 /* The sum of positions in the input chains. */
1083 /* The position in the chains of SRC and DST dataflow sets. */
1088 /* Compare function for qsort, order the structures by POS element. */
1091 variable_union_info_cmp_pos (const void *n1, const void *n2)
1093 const struct variable_union_info *i1 = n1;
1094 const struct variable_union_info *i2 = n2;
1096 if (i1->pos != i2->pos)
1097 return i1->pos - i2->pos;
1099 return (i1->pos_dst - i2->pos_dst);
1102 /* Compute union of location parts of variable *SLOT and the same variable
1103 from hash table DATA. Compute "sorted" union of the location chains
1104 for common offsets, i.e. the locations of a variable part are sorted by
1105 a priority where the priority is the sum of the positions in the 2 chains
1106 (if a location is only in one list the position in the second list is
1107 defined to be larger than the length of the chains).
1108 When we are updating the location parts the newest location is in the
1109 beginning of the chain, so when we do the described "sorted" union
1110 we keep the newest locations in the beginning. */
1113 variable_union (void **slot, void *data)
1115 variable src, dst, *dstp;
1116 dataflow_set *set = (dataflow_set *) data;
1119 src = *(variable *) slot;
1120 dstp = (variable *) htab_find_slot_with_hash (set->vars, src->decl,
1121 VARIABLE_HASH_VAL (src->decl),
1127 /* If CUR_LOC of some variable part is not the first element of
1128 the location chain we are going to change it so we have to make
1129 a copy of the variable. */
1130 for (k = 0; k < src->n_var_parts; k++)
1132 gcc_assert (!src->var_part[k].loc_chain
1133 == !src->var_part[k].cur_loc);
1134 if (src->var_part[k].loc_chain)
1136 gcc_assert (src->var_part[k].cur_loc);
1137 if (src->var_part[k].cur_loc != src->var_part[k].loc_chain->loc)
1141 if (k < src->n_var_parts)
1143 enum var_init_status status = VAR_INIT_STATUS_UNKNOWN;
1145 if (! flag_var_tracking_uninit)
1146 status = VAR_INIT_STATUS_INITIALIZED;
1148 unshare_variable (set, src, status);
1153 /* Continue traversing the hash table. */
1159 gcc_assert (src->n_var_parts);
1161 /* Count the number of location parts, result is K. */
1162 for (i = 0, j = 0, k = 0;
1163 i < src->n_var_parts && j < dst->n_var_parts; k++)
1165 if (src->var_part[i].offset == dst->var_part[j].offset)
1170 else if (src->var_part[i].offset < dst->var_part[j].offset)
1175 k += src->n_var_parts - i;
1176 k += dst->n_var_parts - j;
1178 /* We track only variables whose size is <= MAX_VAR_PARTS bytes
1179 thus there are at most MAX_VAR_PARTS different offsets. */
1180 gcc_assert (k <= MAX_VAR_PARTS);
1182 if (dst->refcount > 1 && dst->n_var_parts != k)
1184 enum var_init_status status = VAR_INIT_STATUS_UNKNOWN;
1186 if (! flag_var_tracking_uninit)
1187 status = VAR_INIT_STATUS_INITIALIZED;
1188 dst = unshare_variable (set, dst, status);
1191 i = src->n_var_parts - 1;
1192 j = dst->n_var_parts - 1;
1193 dst->n_var_parts = k;
1195 for (k--; k >= 0; k--)
1197 location_chain node, node2;
1199 if (i >= 0 && j >= 0
1200 && src->var_part[i].offset == dst->var_part[j].offset)
1202 /* Compute the "sorted" union of the chains, i.e. the locations which
1203 are in both chains go first, they are sorted by the sum of
1204 positions in the chains. */
1207 struct variable_union_info *vui;
1209 /* If DST is shared compare the location chains.
1210 If they are different we will modify the chain in DST with
1211 high probability so make a copy of DST. */
1212 if (dst->refcount > 1)
1214 for (node = src->var_part[i].loc_chain,
1215 node2 = dst->var_part[j].loc_chain; node && node2;
1216 node = node->next, node2 = node2->next)
1218 if (!((REG_P (node2->loc)
1219 && REG_P (node->loc)
1220 && REGNO (node2->loc) == REGNO (node->loc))
1221 || rtx_equal_p (node2->loc, node->loc)))
1222 if (node2->init < node->init)
1223 node2->init = node->init;
1227 dst = unshare_variable (set, dst, VAR_INIT_STATUS_UNKNOWN);
1231 for (node = src->var_part[i].loc_chain; node; node = node->next)
1234 for (node = dst->var_part[j].loc_chain; node; node = node->next)
1236 vui = XCNEWVEC (struct variable_union_info, src_l + dst_l);
1238 /* Fill in the locations from DST. */
1239 for (node = dst->var_part[j].loc_chain, jj = 0; node;
1240 node = node->next, jj++)
1243 vui[jj].pos_dst = jj;
1245 /* Value larger than a sum of 2 valid positions. */
1246 vui[jj].pos_src = src_l + dst_l;
1249 /* Fill in the locations from SRC. */
1251 for (node = src->var_part[i].loc_chain, ii = 0; node;
1252 node = node->next, ii++)
1254 /* Find location from NODE. */
1255 for (jj = 0; jj < dst_l; jj++)
1257 if ((REG_P (vui[jj].lc->loc)
1258 && REG_P (node->loc)
1259 && REGNO (vui[jj].lc->loc) == REGNO (node->loc))
1260 || rtx_equal_p (vui[jj].lc->loc, node->loc))
1262 vui[jj].pos_src = ii;
1266 if (jj >= dst_l) /* The location has not been found. */
1268 location_chain new_node;
1270 /* Copy the location from SRC. */
1271 new_node = pool_alloc (loc_chain_pool);
1272 new_node->loc = node->loc;
1273 new_node->init = node->init;
1274 if (!node->set_src || MEM_P (node->set_src))
1275 new_node->set_src = NULL;
1277 new_node->set_src = node->set_src;
1278 vui[n].lc = new_node;
1279 vui[n].pos_src = ii;
1280 vui[n].pos_dst = src_l + dst_l;
1285 for (ii = 0; ii < src_l + dst_l; ii++)
1286 vui[ii].pos = vui[ii].pos_src + vui[ii].pos_dst;
1288 qsort (vui, n, sizeof (struct variable_union_info),
1289 variable_union_info_cmp_pos);
1291 /* Reconnect the nodes in sorted order. */
1292 for (ii = 1; ii < n; ii++)
1293 vui[ii - 1].lc->next = vui[ii].lc;
1294 vui[n - 1].lc->next = NULL;
1296 dst->var_part[k].loc_chain = vui[0].lc;
1297 dst->var_part[k].offset = dst->var_part[j].offset;
1303 else if ((i >= 0 && j >= 0
1304 && src->var_part[i].offset < dst->var_part[j].offset)
1307 dst->var_part[k] = dst->var_part[j];
1310 else if ((i >= 0 && j >= 0
1311 && src->var_part[i].offset > dst->var_part[j].offset)
1314 location_chain *nextp;
1316 /* Copy the chain from SRC. */
1317 nextp = &dst->var_part[k].loc_chain;
1318 for (node = src->var_part[i].loc_chain; node; node = node->next)
1320 location_chain new_lc;
1322 new_lc = pool_alloc (loc_chain_pool);
1323 new_lc->next = NULL;
1324 new_lc->init = node->init;
1325 if (!node->set_src || MEM_P (node->set_src))
1326 new_lc->set_src = NULL;
1328 new_lc->set_src = node->set_src;
1329 new_lc->loc = node->loc;
1332 nextp = &new_lc->next;
1335 dst->var_part[k].offset = src->var_part[i].offset;
1339 /* We are at the basic block boundary when computing union
1340 so set the CUR_LOC to be the first element of the chain. */
1341 if (dst->var_part[k].loc_chain)
1342 dst->var_part[k].cur_loc = dst->var_part[k].loc_chain->loc;
1344 dst->var_part[k].cur_loc = NULL;
1347 for (i = 0; i < src->n_var_parts && i < dst->n_var_parts; i++)
1349 location_chain node, node2;
1350 for (node = src->var_part[i].loc_chain; node; node = node->next)
1351 for (node2 = dst->var_part[i].loc_chain; node2; node2 = node2->next)
1352 if (rtx_equal_p (node->loc, node2->loc))
1354 if (node->init > node2->init)
1355 node2->init = node->init;
1359 /* Continue traversing the hash table. */
1363 /* Compute union of dataflow sets SRC and DST and store it to DST. */
1366 dataflow_set_union (dataflow_set *dst, dataflow_set *src)
1370 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1371 attrs_list_union (&dst->regs[i], src->regs[i]);
1373 htab_traverse (src->vars, variable_union, dst);
1376 /* Flag whether two dataflow sets being compared contain different data. */
1378 dataflow_set_different_value;
1381 variable_part_different_p (variable_part *vp1, variable_part *vp2)
1383 location_chain lc1, lc2;
1385 for (lc1 = vp1->loc_chain; lc1; lc1 = lc1->next)
1387 for (lc2 = vp2->loc_chain; lc2; lc2 = lc2->next)
1389 if (REG_P (lc1->loc) && REG_P (lc2->loc))
1391 if (REGNO (lc1->loc) == REGNO (lc2->loc))
1394 if (rtx_equal_p (lc1->loc, lc2->loc))
1403 /* Return true if variables VAR1 and VAR2 are different.
1404 If COMPARE_CURRENT_LOCATION is true compare also the cur_loc of each
1408 variable_different_p (variable var1, variable var2,
1409 bool compare_current_location)
1416 if (var1->n_var_parts != var2->n_var_parts)
1419 for (i = 0; i < var1->n_var_parts; i++)
1421 if (var1->var_part[i].offset != var2->var_part[i].offset)
1423 if (compare_current_location)
1425 if (!((REG_P (var1->var_part[i].cur_loc)
1426 && REG_P (var2->var_part[i].cur_loc)
1427 && (REGNO (var1->var_part[i].cur_loc)
1428 == REGNO (var2->var_part[i].cur_loc)))
1429 || rtx_equal_p (var1->var_part[i].cur_loc,
1430 var2->var_part[i].cur_loc)))
1433 if (variable_part_different_p (&var1->var_part[i], &var2->var_part[i]))
1435 if (variable_part_different_p (&var2->var_part[i], &var1->var_part[i]))
1441 /* Compare variable *SLOT with the same variable in hash table DATA
1442 and set DATAFLOW_SET_DIFFERENT_VALUE if they are different. */
1445 dataflow_set_different_1 (void **slot, void *data)
1447 htab_t htab = (htab_t) data;
1448 variable var1, var2;
1450 var1 = *(variable *) slot;
1451 var2 = htab_find_with_hash (htab, var1->decl,
1452 VARIABLE_HASH_VAL (var1->decl));
1455 dataflow_set_different_value = true;
1457 /* Stop traversing the hash table. */
1461 if (variable_different_p (var1, var2, false))
1463 dataflow_set_different_value = true;
1465 /* Stop traversing the hash table. */
1469 /* Continue traversing the hash table. */
1473 /* Compare variable *SLOT with the same variable in hash table DATA
1474 and set DATAFLOW_SET_DIFFERENT_VALUE if they are different. */
1477 dataflow_set_different_2 (void **slot, void *data)
1479 htab_t htab = (htab_t) data;
1480 variable var1, var2;
1482 var1 = *(variable *) slot;
1483 var2 = htab_find_with_hash (htab, var1->decl,
1484 VARIABLE_HASH_VAL (var1->decl));
1487 dataflow_set_different_value = true;
1489 /* Stop traversing the hash table. */
1493 /* If both variables are defined they have been already checked for
1495 gcc_assert (!variable_different_p (var1, var2, false));
1497 /* Continue traversing the hash table. */
1501 /* Return true if dataflow sets OLD_SET and NEW_SET differ. */
1504 dataflow_set_different (dataflow_set *old_set, dataflow_set *new_set)
1506 dataflow_set_different_value = false;
1508 htab_traverse (old_set->vars, dataflow_set_different_1, new_set->vars);
1509 if (!dataflow_set_different_value)
1511 /* We have compared the variables which are in both hash tables
1512 so now only check whether there are some variables in NEW_SET->VARS
1513 which are not in OLD_SET->VARS. */
1514 htab_traverse (new_set->vars, dataflow_set_different_2, old_set->vars);
1516 return dataflow_set_different_value;
1519 /* Free the contents of dataflow set SET. */
1522 dataflow_set_destroy (dataflow_set *set)
1526 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1527 attrs_list_clear (&set->regs[i]);
1529 htab_delete (set->vars);
1533 /* Return true if RTL X contains a SYMBOL_REF. */
1536 contains_symbol_ref (rtx x)
1545 code = GET_CODE (x);
1546 if (code == SYMBOL_REF)
1549 fmt = GET_RTX_FORMAT (code);
1550 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
1554 if (contains_symbol_ref (XEXP (x, i)))
1557 else if (fmt[i] == 'E')
1560 for (j = 0; j < XVECLEN (x, i); j++)
1561 if (contains_symbol_ref (XVECEXP (x, i, j)))
1569 /* Shall EXPR be tracked? */
1572 track_expr_p (tree expr)
1577 /* If EXPR is not a parameter or a variable do not track it. */
1578 if (TREE_CODE (expr) != VAR_DECL && TREE_CODE (expr) != PARM_DECL)
1581 /* It also must have a name... */
1582 if (!DECL_NAME (expr))
1585 /* ... and a RTL assigned to it. */
1586 decl_rtl = DECL_RTL_IF_SET (expr);
1590 /* If this expression is really a debug alias of some other declaration, we
1591 don't need to track this expression if the ultimate declaration is
1594 if (DECL_DEBUG_EXPR_IS_FROM (realdecl) && DECL_DEBUG_EXPR (realdecl))
1596 realdecl = DECL_DEBUG_EXPR (realdecl);
1597 /* ??? We don't yet know how to emit DW_OP_piece for variable
1598 that has been SRA'ed. */
1599 if (!DECL_P (realdecl))
1603 /* Do not track EXPR if REALDECL it should be ignored for debugging
1605 if (DECL_IGNORED_P (realdecl))
1608 /* Do not track global variables until we are able to emit correct location
1610 if (TREE_STATIC (realdecl))
1613 /* When the EXPR is a DECL for alias of some variable (see example)
1614 the TREE_STATIC flag is not used. Disable tracking all DECLs whose
1615 DECL_RTL contains SYMBOL_REF.
1618 extern char **_dl_argv_internal __attribute__ ((alias ("_dl_argv")));
1621 if (MEM_P (decl_rtl)
1622 && contains_symbol_ref (XEXP (decl_rtl, 0)))
1625 /* If RTX is a memory it should not be very large (because it would be
1626 an array or struct). */
1627 if (MEM_P (decl_rtl))
1629 /* Do not track structures and arrays. */
1630 if (GET_MODE (decl_rtl) == BLKmode
1631 || AGGREGATE_TYPE_P (TREE_TYPE (realdecl)))
1633 if (MEM_SIZE (decl_rtl)
1634 && INTVAL (MEM_SIZE (decl_rtl)) > MAX_VAR_PARTS)
1641 /* Determine whether a given LOC refers to the same variable part as
1645 same_variable_part_p (rtx loc, tree expr, HOST_WIDE_INT offset)
1648 HOST_WIDE_INT offset2;
1650 if (! DECL_P (expr))
1655 expr2 = REG_EXPR (loc);
1656 offset2 = REG_OFFSET (loc);
1658 else if (MEM_P (loc))
1660 expr2 = MEM_EXPR (loc);
1661 offset2 = MEM_OFFSET (loc) ? INTVAL (MEM_OFFSET (loc)) : 0;
1666 if (! expr2 || ! DECL_P (expr2))
1669 expr = var_debug_decl (expr);
1670 expr2 = var_debug_decl (expr2);
1672 return (expr == expr2 && offset == offset2);
1676 /* Count uses (register and memory references) LOC which will be tracked.
1677 INSN is instruction which the LOC is part of. */
1680 count_uses (rtx *loc, void *insn)
1682 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1686 gcc_assert (REGNO (*loc) < FIRST_PSEUDO_REGISTER);
1689 else if (MEM_P (*loc)
1691 && track_expr_p (MEM_EXPR (*loc)))
1699 /* Helper function for finding all uses of REG/MEM in X in insn INSN. */
1702 count_uses_1 (rtx *x, void *insn)
1704 for_each_rtx (x, count_uses, insn);
1707 /* Count stores (register and memory references) LOC which will be tracked.
1708 INSN is instruction which the LOC is part of. */
1711 count_stores (rtx loc, rtx expr ATTRIBUTE_UNUSED, void *insn)
1713 count_uses (&loc, insn);
1716 /* Add uses (register and memory references) LOC which will be tracked
1717 to VTI (bb)->mos. INSN is instruction which the LOC is part of. */
1720 add_uses (rtx *loc, void *insn)
1724 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1725 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1727 mo->type = ((REG_EXPR (*loc) && track_expr_p (REG_EXPR (*loc)))
1728 ? MO_USE : MO_USE_NO_VAR);
1730 mo->insn = (rtx) insn;
1732 else if (MEM_P (*loc)
1734 && track_expr_p (MEM_EXPR (*loc)))
1736 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1737 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1741 mo->insn = (rtx) insn;
1747 /* Helper function for finding all uses of REG/MEM in X in insn INSN. */
1750 add_uses_1 (rtx *x, void *insn)
1752 for_each_rtx (x, add_uses, insn);
1755 /* Add stores (register and memory references) LOC which will be tracked
1756 to VTI (bb)->mos. EXPR is the RTL expression containing the store.
1757 INSN is instruction which the LOC is part of. */
1760 add_stores (rtx loc, rtx expr, void *insn)
1764 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1765 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1767 if (GET_CODE (expr) == CLOBBER
1769 || ! track_expr_p (REG_EXPR (loc)))
1770 mo->type = MO_CLOBBER;
1771 else if (GET_CODE (expr) == SET
1772 && SET_DEST (expr) == loc
1773 && same_variable_part_p (SET_SRC (expr),
1780 mo->insn = (rtx) insn;
1782 else if (MEM_P (loc)
1784 && track_expr_p (MEM_EXPR (loc)))
1786 basic_block bb = BLOCK_FOR_INSN ((rtx) insn);
1787 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
1789 if (GET_CODE (expr) == CLOBBER)
1790 mo->type = MO_CLOBBER;
1791 else if (GET_CODE (expr) == SET
1792 && SET_DEST (expr) == loc
1793 && same_variable_part_p (SET_SRC (expr),
1796 ? INTVAL (MEM_OFFSET (loc)) : 0))
1801 mo->insn = (rtx) insn;
1805 static enum var_init_status
1806 find_src_status (dataflow_set *in, rtx loc, rtx insn)
1809 tree decl = NULL_TREE;
1810 enum var_init_status status = VAR_INIT_STATUS_UNINITIALIZED;
1812 if (! flag_var_tracking_uninit)
1813 status = VAR_INIT_STATUS_INITIALIZED;
1815 if (GET_CODE (PATTERN (insn)) == SET)
1816 src = SET_SRC (PATTERN (insn));
1817 else if (GET_CODE (PATTERN (insn)) == PARALLEL
1818 || GET_CODE (PATTERN (insn)) == SEQUENCE)
1821 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
1822 if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET
1823 && SET_DEST (XVECEXP (PATTERN (insn), 0, i)) == loc)
1824 src = SET_SRC (XVECEXP (PATTERN (insn), 0, i));
1828 decl = var_debug_decl (REG_EXPR (src));
1829 else if (MEM_P (src))
1830 decl = var_debug_decl (MEM_EXPR (src));
1833 status = get_init_value (in, src, decl);
1838 /* LOC is the destination the variable is being copied to. INSN
1839 contains the copy instruction. SET is the dataflow set containing
1840 the variable in LOC. */
1843 find_src_set_src (dataflow_set *set, rtx loc, rtx insn)
1845 tree decl = NULL_TREE; /* The variable being copied around. */
1846 rtx src = NULL_RTX; /* The location "decl" is being copied from. */
1847 rtx set_src = NULL_RTX; /* The value for "decl" stored in "src". */
1850 location_chain nextp;
1854 if (GET_CODE (PATTERN (insn)) == SET)
1855 src = SET_SRC (PATTERN (insn));
1856 else if (GET_CODE (PATTERN (insn)) == PARALLEL
1857 || GET_CODE (PATTERN (insn)) == SEQUENCE)
1859 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
1860 if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == SET
1861 && SET_DEST (XVECEXP (PATTERN (insn), 0, i)) == loc)
1862 src = SET_SRC (XVECEXP (PATTERN (insn), 0, i));
1866 decl = var_debug_decl (REG_EXPR (src));
1867 else if (MEM_P (src))
1868 decl = var_debug_decl (MEM_EXPR (src));
1872 slot = htab_find_slot_with_hash (set->vars, decl,
1873 VARIABLE_HASH_VAL (decl), NO_INSERT);
1877 var = *(variable *) slot;
1879 for (i = 0; i < var->n_var_parts && !found; i++)
1880 for (nextp = var->var_part[i].loc_chain; nextp && !found;
1881 nextp = nextp->next)
1882 if (rtx_equal_p (nextp->loc, src))
1884 set_src = nextp->set_src;
1894 /* Compute the changes of variable locations in the basic block BB. */
1897 compute_bb_dataflow (basic_block bb)
1901 dataflow_set old_out;
1902 dataflow_set *in = &VTI (bb)->in;
1903 dataflow_set *out = &VTI (bb)->out;
1905 dataflow_set_init (&old_out, htab_elements (VTI (bb)->out.vars) + 3);
1906 dataflow_set_copy (&old_out, out);
1907 dataflow_set_copy (out, in);
1909 n = VTI (bb)->n_mos;
1910 for (i = 0; i < n; i++)
1912 switch (VTI (bb)->mos[i].type)
1915 for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
1916 if (TEST_HARD_REG_BIT (call_used_reg_set, r))
1917 var_regno_delete (out, r);
1922 rtx loc = VTI (bb)->mos[i].u.loc;
1923 enum var_init_status status = VAR_INIT_STATUS_UNINITIALIZED;
1925 if (! flag_var_tracking_uninit)
1926 status = VAR_INIT_STATUS_INITIALIZED;
1928 if (GET_CODE (loc) == REG)
1929 var_reg_set (out, loc, status, NULL);
1930 else if (GET_CODE (loc) == MEM)
1931 var_mem_set (out, loc, status, NULL);
1937 rtx loc = VTI (bb)->mos[i].u.loc;
1939 rtx insn = VTI (bb)->mos[i].insn;
1941 if (GET_CODE (PATTERN (insn)) == SET)
1942 set_src = SET_SRC (PATTERN (insn));
1943 else if (GET_CODE (PATTERN (insn)) == PARALLEL
1944 || GET_CODE (PATTERN (insn)) == SEQUENCE)
1947 for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--)
1948 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET
1949 && SET_DEST (XVECEXP (PATTERN (insn), 0, j)) == loc)
1950 set_src = SET_SRC (XVECEXP (PATTERN (insn), 0, j));
1954 var_reg_delete_and_set (out, loc, true, VAR_INIT_STATUS_INITIALIZED,
1956 else if (MEM_P (loc))
1957 var_mem_delete_and_set (out, loc, true, VAR_INIT_STATUS_INITIALIZED,
1964 rtx loc = VTI (bb)->mos[i].u.loc;
1965 enum var_init_status src_status;
1968 if (! flag_var_tracking_uninit)
1969 src_status = VAR_INIT_STATUS_INITIALIZED;
1971 src_status = find_src_status (in, loc, VTI (bb)->mos[i].insn);
1973 if (src_status == VAR_INIT_STATUS_UNKNOWN)
1974 src_status = find_src_status (out, loc, VTI (bb)->mos[i].insn);
1976 set_src = find_src_set_src (in, loc, VTI (bb)->mos[i].insn);
1979 var_reg_delete_and_set (out, loc, false, src_status, set_src);
1980 else if (MEM_P (loc))
1981 var_mem_delete_and_set (out, loc, false, src_status, set_src);
1987 rtx loc = VTI (bb)->mos[i].u.loc;
1990 var_reg_delete (out, loc, false);
1991 else if (MEM_P (loc))
1992 var_mem_delete (out, loc, false);
1998 rtx loc = VTI (bb)->mos[i].u.loc;
2001 var_reg_delete (out, loc, true);
2002 else if (MEM_P (loc))
2003 var_mem_delete (out, loc, true);
2008 out->stack_adjust += VTI (bb)->mos[i].u.adjust;
2013 changed = dataflow_set_different (&old_out, out);
2014 dataflow_set_destroy (&old_out);
2018 /* Find the locations of variables in the whole function. */
2021 vt_find_locations (void)
2023 fibheap_t worklist, pending, fibheap_swap;
2024 sbitmap visited, in_worklist, in_pending, sbitmap_swap;
2031 /* Compute reverse completion order of depth first search of the CFG
2032 so that the data-flow runs faster. */
2033 rc_order = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
2034 bb_order = XNEWVEC (int, last_basic_block);
2035 pre_and_rev_post_order_compute (NULL, rc_order, false);
2036 for (i = 0; i < n_basic_blocks - NUM_FIXED_BLOCKS; i++)
2037 bb_order[rc_order[i]] = i;
2040 worklist = fibheap_new ();
2041 pending = fibheap_new ();
2042 visited = sbitmap_alloc (last_basic_block);
2043 in_worklist = sbitmap_alloc (last_basic_block);
2044 in_pending = sbitmap_alloc (last_basic_block);
2045 sbitmap_zero (in_worklist);
2048 fibheap_insert (pending, bb_order[bb->index], bb);
2049 sbitmap_ones (in_pending);
2051 while (!fibheap_empty (pending))
2053 fibheap_swap = pending;
2055 worklist = fibheap_swap;
2056 sbitmap_swap = in_pending;
2057 in_pending = in_worklist;
2058 in_worklist = sbitmap_swap;
2060 sbitmap_zero (visited);
2062 while (!fibheap_empty (worklist))
2064 bb = fibheap_extract_min (worklist);
2065 RESET_BIT (in_worklist, bb->index);
2066 if (!TEST_BIT (visited, bb->index))
2071 SET_BIT (visited, bb->index);
2073 /* Calculate the IN set as union of predecessor OUT sets. */
2074 dataflow_set_clear (&VTI (bb)->in);
2075 FOR_EACH_EDGE (e, ei, bb->preds)
2077 dataflow_set_union (&VTI (bb)->in, &VTI (e->src)->out);
2080 changed = compute_bb_dataflow (bb);
2083 FOR_EACH_EDGE (e, ei, bb->succs)
2085 if (e->dest == EXIT_BLOCK_PTR)
2091 if (TEST_BIT (visited, e->dest->index))
2093 if (!TEST_BIT (in_pending, e->dest->index))
2095 /* Send E->DEST to next round. */
2096 SET_BIT (in_pending, e->dest->index);
2097 fibheap_insert (pending,
2098 bb_order[e->dest->index],
2102 else if (!TEST_BIT (in_worklist, e->dest->index))
2104 /* Add E->DEST to current round. */
2105 SET_BIT (in_worklist, e->dest->index);
2106 fibheap_insert (worklist, bb_order[e->dest->index],
2116 fibheap_delete (worklist);
2117 fibheap_delete (pending);
2118 sbitmap_free (visited);
2119 sbitmap_free (in_worklist);
2120 sbitmap_free (in_pending);
2123 /* Print the content of the LIST to dump file. */
2126 dump_attrs_list (attrs list)
2128 for (; list; list = list->next)
2130 print_mem_expr (dump_file, list->decl);
2131 fprintf (dump_file, "+" HOST_WIDE_INT_PRINT_DEC, list->offset);
2133 fprintf (dump_file, "\n");
2136 /* Print the information about variable *SLOT to dump file. */
2139 dump_variable (void **slot, void *data ATTRIBUTE_UNUSED)
2141 variable var = *(variable *) slot;
2143 location_chain node;
2145 fprintf (dump_file, " name: %s\n",
2146 IDENTIFIER_POINTER (DECL_NAME (var->decl)));
2147 for (i = 0; i < var->n_var_parts; i++)
2149 fprintf (dump_file, " offset %ld\n",
2150 (long) var->var_part[i].offset);
2151 for (node = var->var_part[i].loc_chain; node; node = node->next)
2153 fprintf (dump_file, " ");
2154 if (node->init == VAR_INIT_STATUS_UNINITIALIZED)
2155 fprintf (dump_file, "[uninit]");
2156 print_rtl_single (dump_file, node->loc);
2160 /* Continue traversing the hash table. */
2164 /* Print the information about variables from hash table VARS to dump file. */
2167 dump_vars (htab_t vars)
2169 if (htab_elements (vars) > 0)
2171 fprintf (dump_file, "Variables:\n");
2172 htab_traverse (vars, dump_variable, NULL);
2176 /* Print the dataflow set SET to dump file. */
2179 dump_dataflow_set (dataflow_set *set)
2183 fprintf (dump_file, "Stack adjustment: " HOST_WIDE_INT_PRINT_DEC "\n",
2185 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
2189 fprintf (dump_file, "Reg %d:", i);
2190 dump_attrs_list (set->regs[i]);
2193 dump_vars (set->vars);
2194 fprintf (dump_file, "\n");
2197 /* Print the IN and OUT sets for each basic block to dump file. */
2200 dump_dataflow_sets (void)
2206 fprintf (dump_file, "\nBasic block %d:\n", bb->index);
2207 fprintf (dump_file, "IN:\n");
2208 dump_dataflow_set (&VTI (bb)->in);
2209 fprintf (dump_file, "OUT:\n");
2210 dump_dataflow_set (&VTI (bb)->out);
2214 /* Add variable VAR to the hash table of changed variables and
2215 if it has no locations delete it from hash table HTAB. */
2218 variable_was_changed (variable var, htab_t htab)
2220 hashval_t hash = VARIABLE_HASH_VAL (var->decl);
2226 slot = (variable *) htab_find_slot_with_hash (changed_variables,
2227 var->decl, hash, INSERT);
2229 if (htab && var->n_var_parts == 0)
2234 empty_var = pool_alloc (var_pool);
2235 empty_var->decl = var->decl;
2236 empty_var->refcount = 1;
2237 empty_var->n_var_parts = 0;
2240 old = htab_find_slot_with_hash (htab, var->decl, hash,
2243 htab_clear_slot (htab, old);
2253 if (var->n_var_parts == 0)
2255 void **slot = htab_find_slot_with_hash (htab, var->decl, hash,
2258 htab_clear_slot (htab, slot);
2263 /* Look for the index in VAR->var_part corresponding to OFFSET.
2264 Return -1 if not found. If INSERTION_POINT is non-NULL, the
2265 referenced int will be set to the index that the part has or should
2266 have, if it should be inserted. */
2269 find_variable_location_part (variable var, HOST_WIDE_INT offset,
2270 int *insertion_point)
2274 /* Find the location part. */
2276 high = var->n_var_parts;
2279 pos = (low + high) / 2;
2280 if (var->var_part[pos].offset < offset)
2287 if (insertion_point)
2288 *insertion_point = pos;
2290 if (pos < var->n_var_parts && var->var_part[pos].offset == offset)
2296 /* Set the part of variable's location in the dataflow set SET. The variable
2297 part is specified by variable's declaration DECL and offset OFFSET and the
2298 part's location by LOC. */
2301 set_variable_part (dataflow_set *set, rtx loc, tree decl, HOST_WIDE_INT offset,
2302 enum var_init_status initialized, rtx set_src)
2305 location_chain node, next;
2306 location_chain *nextp;
2310 slot = htab_find_slot_with_hash (set->vars, decl,
2311 VARIABLE_HASH_VAL (decl), INSERT);
2314 /* Create new variable information. */
2315 var = pool_alloc (var_pool);
2318 var->n_var_parts = 1;
2319 var->var_part[0].offset = offset;
2320 var->var_part[0].loc_chain = NULL;
2321 var->var_part[0].cur_loc = NULL;
2329 var = (variable) *slot;
2331 pos = find_variable_location_part (var, offset, &inspos);
2335 node = var->var_part[pos].loc_chain;
2338 && ((REG_P (node->loc) && REG_P (loc)
2339 && REGNO (node->loc) == REGNO (loc))
2340 || rtx_equal_p (node->loc, loc)))
2342 /* LOC is in the beginning of the chain so we have nothing
2344 if (node->init < initialized)
2345 node->init = initialized;
2346 if (set_src != NULL)
2347 node->set_src = set_src;
2354 /* We have to make a copy of a shared variable. */
2355 if (var->refcount > 1)
2356 var = unshare_variable (set, var, initialized);
2361 /* We have not found the location part, new one will be created. */
2363 /* We have to make a copy of the shared variable. */
2364 if (var->refcount > 1)
2365 var = unshare_variable (set, var, initialized);
2367 /* We track only variables whose size is <= MAX_VAR_PARTS bytes
2368 thus there are at most MAX_VAR_PARTS different offsets. */
2369 gcc_assert (var->n_var_parts < MAX_VAR_PARTS);
2371 /* We have to move the elements of array starting at index
2372 inspos to the next position. */
2373 for (pos = var->n_var_parts; pos > inspos; pos--)
2374 var->var_part[pos] = var->var_part[pos - 1];
2377 var->var_part[pos].offset = offset;
2378 var->var_part[pos].loc_chain = NULL;
2379 var->var_part[pos].cur_loc = NULL;
2383 /* Delete the location from the list. */
2384 nextp = &var->var_part[pos].loc_chain;
2385 for (node = var->var_part[pos].loc_chain; node; node = next)
2388 if ((REG_P (node->loc) && REG_P (loc)
2389 && REGNO (node->loc) == REGNO (loc))
2390 || rtx_equal_p (node->loc, loc))
2392 /* Save these values, to assign to the new node, before
2393 deleting this one. */
2394 if (node->init > initialized)
2395 initialized = node->init;
2396 if (node->set_src != NULL && set_src == NULL)
2397 set_src = node->set_src;
2398 pool_free (loc_chain_pool, node);
2403 nextp = &node->next;
2406 /* Add the location to the beginning. */
2407 node = pool_alloc (loc_chain_pool);
2409 node->init = initialized;
2410 node->set_src = set_src;
2411 node->next = var->var_part[pos].loc_chain;
2412 var->var_part[pos].loc_chain = node;
2414 /* If no location was emitted do so. */
2415 if (var->var_part[pos].cur_loc == NULL)
2417 var->var_part[pos].cur_loc = loc;
2418 variable_was_changed (var, set->vars);
2422 /* Remove all recorded register locations for the given variable part
2423 from dataflow set SET, except for those that are identical to loc.
2424 The variable part is specified by variable's declaration DECL and
2428 clobber_variable_part (dataflow_set *set, rtx loc, tree decl,
2429 HOST_WIDE_INT offset, rtx set_src)
2433 if (! decl || ! DECL_P (decl))
2436 slot = htab_find_slot_with_hash (set->vars, decl, VARIABLE_HASH_VAL (decl),
2440 variable var = (variable) *slot;
2441 int pos = find_variable_location_part (var, offset, NULL);
2445 location_chain node, next;
2447 /* Remove the register locations from the dataflow set. */
2448 next = var->var_part[pos].loc_chain;
2449 for (node = next; node; node = next)
2452 if (node->loc != loc
2453 && (!flag_var_tracking_uninit
2456 || !rtx_equal_p (set_src, node->set_src)))
2458 if (REG_P (node->loc))
2463 /* Remove the variable part from the register's
2464 list, but preserve any other variable parts
2465 that might be regarded as live in that same
2467 anextp = &set->regs[REGNO (node->loc)];
2468 for (anode = *anextp; anode; anode = anext)
2470 anext = anode->next;
2471 if (anode->decl == decl
2472 && anode->offset == offset)
2474 pool_free (attrs_pool, anode);
2480 delete_variable_part (set, node->loc, decl, offset);
2487 /* Delete the part of variable's location from dataflow set SET. The variable
2488 part is specified by variable's declaration DECL and offset OFFSET and the
2489 part's location by LOC. */
2492 delete_variable_part (dataflow_set *set, rtx loc, tree decl,
2493 HOST_WIDE_INT offset)
2497 slot = htab_find_slot_with_hash (set->vars, decl, VARIABLE_HASH_VAL (decl),
2501 variable var = (variable) *slot;
2502 int pos = find_variable_location_part (var, offset, NULL);
2506 location_chain node, next;
2507 location_chain *nextp;
2510 if (var->refcount > 1)
2512 /* If the variable contains the location part we have to
2513 make a copy of the variable. */
2514 for (node = var->var_part[pos].loc_chain; node;
2517 if ((REG_P (node->loc) && REG_P (loc)
2518 && REGNO (node->loc) == REGNO (loc))
2519 || rtx_equal_p (node->loc, loc))
2521 enum var_init_status status = VAR_INIT_STATUS_UNKNOWN;
2522 if (! flag_var_tracking_uninit)
2523 status = VAR_INIT_STATUS_INITIALIZED;
2524 var = unshare_variable (set, var, status);
2530 /* Delete the location part. */
2531 nextp = &var->var_part[pos].loc_chain;
2532 for (node = *nextp; node; node = next)
2535 if ((REG_P (node->loc) && REG_P (loc)
2536 && REGNO (node->loc) == REGNO (loc))
2537 || rtx_equal_p (node->loc, loc))
2539 pool_free (loc_chain_pool, node);
2544 nextp = &node->next;
2547 /* If we have deleted the location which was last emitted
2548 we have to emit new location so add the variable to set
2549 of changed variables. */
2550 if (var->var_part[pos].cur_loc
2552 && REG_P (var->var_part[pos].cur_loc)
2553 && REGNO (loc) == REGNO (var->var_part[pos].cur_loc))
2554 || rtx_equal_p (loc, var->var_part[pos].cur_loc)))
2557 if (var->var_part[pos].loc_chain)
2558 var->var_part[pos].cur_loc = var->var_part[pos].loc_chain->loc;
2563 if (var->var_part[pos].loc_chain == NULL)
2566 while (pos < var->n_var_parts)
2568 var->var_part[pos] = var->var_part[pos + 1];
2573 variable_was_changed (var, set->vars);
2578 /* Emit the NOTE_INSN_VAR_LOCATION for variable *VARP. DATA contains
2579 additional parameters: WHERE specifies whether the note shall be emitted
2580 before of after instruction INSN. */
2583 emit_note_insn_var_location (void **varp, void *data)
2585 variable var = *(variable *) varp;
2586 rtx insn = ((emit_note_data *)data)->insn;
2587 enum emit_note_where where = ((emit_note_data *)data)->where;
2589 int i, j, n_var_parts;
2591 enum var_init_status initialized = VAR_INIT_STATUS_UNINITIALIZED;
2592 HOST_WIDE_INT last_limit;
2593 tree type_size_unit;
2594 HOST_WIDE_INT offsets[MAX_VAR_PARTS];
2595 rtx loc[MAX_VAR_PARTS];
2597 gcc_assert (var->decl);
2599 if (! flag_var_tracking_uninit)
2600 initialized = VAR_INIT_STATUS_INITIALIZED;
2605 for (i = 0; i < var->n_var_parts; i++)
2607 enum machine_mode mode, wider_mode;
2609 if (last_limit < var->var_part[i].offset)
2614 else if (last_limit > var->var_part[i].offset)
2616 offsets[n_var_parts] = var->var_part[i].offset;
2617 loc[n_var_parts] = var->var_part[i].loc_chain->loc;
2618 mode = GET_MODE (loc[n_var_parts]);
2619 initialized = var->var_part[i].loc_chain->init;
2620 last_limit = offsets[n_var_parts] + GET_MODE_SIZE (mode);
2622 /* Attempt to merge adjacent registers or memory. */
2623 wider_mode = GET_MODE_WIDER_MODE (mode);
2624 for (j = i + 1; j < var->n_var_parts; j++)
2625 if (last_limit <= var->var_part[j].offset)
2627 if (j < var->n_var_parts
2628 && wider_mode != VOIDmode
2629 && GET_CODE (loc[n_var_parts])
2630 == GET_CODE (var->var_part[j].loc_chain->loc)
2631 && mode == GET_MODE (var->var_part[j].loc_chain->loc)
2632 && last_limit == var->var_part[j].offset)
2635 rtx loc2 = var->var_part[j].loc_chain->loc;
2637 if (REG_P (loc[n_var_parts])
2638 && hard_regno_nregs[REGNO (loc[n_var_parts])][mode] * 2
2639 == hard_regno_nregs[REGNO (loc[n_var_parts])][wider_mode]
2640 && end_hard_regno (mode, REGNO (loc[n_var_parts]))
2643 if (! WORDS_BIG_ENDIAN && ! BYTES_BIG_ENDIAN)
2644 new_loc = simplify_subreg (wider_mode, loc[n_var_parts],
2646 else if (WORDS_BIG_ENDIAN && BYTES_BIG_ENDIAN)
2647 new_loc = simplify_subreg (wider_mode, loc2, mode, 0);
2650 if (!REG_P (new_loc)
2651 || REGNO (new_loc) != REGNO (loc[n_var_parts]))
2654 REG_ATTRS (new_loc) = REG_ATTRS (loc[n_var_parts]);
2657 else if (MEM_P (loc[n_var_parts])
2658 && GET_CODE (XEXP (loc2, 0)) == PLUS
2659 && GET_CODE (XEXP (XEXP (loc2, 0), 0)) == REG
2660 && GET_CODE (XEXP (XEXP (loc2, 0), 1)) == CONST_INT)
2662 if ((GET_CODE (XEXP (loc[n_var_parts], 0)) == REG
2663 && rtx_equal_p (XEXP (loc[n_var_parts], 0),
2664 XEXP (XEXP (loc2, 0), 0))
2665 && INTVAL (XEXP (XEXP (loc2, 0), 1))
2666 == GET_MODE_SIZE (mode))
2667 || (GET_CODE (XEXP (loc[n_var_parts], 0)) == PLUS
2668 && GET_CODE (XEXP (XEXP (loc[n_var_parts], 0), 1))
2670 && rtx_equal_p (XEXP (XEXP (loc[n_var_parts], 0), 0),
2671 XEXP (XEXP (loc2, 0), 0))
2672 && INTVAL (XEXP (XEXP (loc[n_var_parts], 0), 1))
2673 + GET_MODE_SIZE (mode)
2674 == INTVAL (XEXP (XEXP (loc2, 0), 1))))
2675 new_loc = adjust_address_nv (loc[n_var_parts],
2681 loc[n_var_parts] = new_loc;
2683 last_limit = offsets[n_var_parts] + GET_MODE_SIZE (mode);
2689 type_size_unit = TYPE_SIZE_UNIT (TREE_TYPE (var->decl));
2690 if ((unsigned HOST_WIDE_INT) last_limit < TREE_INT_CST_LOW (type_size_unit))
2693 if (where == EMIT_NOTE_AFTER_INSN)
2694 note = emit_note_after (NOTE_INSN_VAR_LOCATION, insn);
2696 note = emit_note_before (NOTE_INSN_VAR_LOCATION, insn);
2698 if (! flag_var_tracking_uninit)
2699 initialized = VAR_INIT_STATUS_INITIALIZED;
2703 NOTE_VAR_LOCATION (note) = gen_rtx_VAR_LOCATION (VOIDmode, var->decl,
2704 NULL_RTX, (int) initialized);
2706 else if (n_var_parts == 1)
2709 = gen_rtx_EXPR_LIST (VOIDmode, loc[0], GEN_INT (offsets[0]));
2711 NOTE_VAR_LOCATION (note) = gen_rtx_VAR_LOCATION (VOIDmode, var->decl,
2715 else if (n_var_parts)
2719 for (i = 0; i < n_var_parts; i++)
2721 = gen_rtx_EXPR_LIST (VOIDmode, loc[i], GEN_INT (offsets[i]));
2723 parallel = gen_rtx_PARALLEL (VOIDmode,
2724 gen_rtvec_v (n_var_parts, loc));
2725 NOTE_VAR_LOCATION (note) = gen_rtx_VAR_LOCATION (VOIDmode, var->decl,
2730 htab_clear_slot (changed_variables, varp);
2732 /* When there are no location parts the variable has been already
2733 removed from hash table and a new empty variable was created.
2734 Free the empty variable. */
2735 if (var->n_var_parts == 0)
2737 pool_free (var_pool, var);
2740 /* Continue traversing the hash table. */
2744 /* Emit NOTE_INSN_VAR_LOCATION note for each variable from a chain
2745 CHANGED_VARIABLES and delete this chain. WHERE specifies whether the notes
2746 shall be emitted before of after instruction INSN. */
2749 emit_notes_for_changes (rtx insn, enum emit_note_where where)
2751 emit_note_data data;
2755 htab_traverse (changed_variables, emit_note_insn_var_location, &data);
2758 /* Add variable *SLOT to the chain CHANGED_VARIABLES if it differs from the
2759 same variable in hash table DATA or is not there at all. */
2762 emit_notes_for_differences_1 (void **slot, void *data)
2764 htab_t new_vars = (htab_t) data;
2765 variable old_var, new_var;
2767 old_var = *(variable *) slot;
2768 new_var = htab_find_with_hash (new_vars, old_var->decl,
2769 VARIABLE_HASH_VAL (old_var->decl));
2773 /* Variable has disappeared. */
2776 empty_var = pool_alloc (var_pool);
2777 empty_var->decl = old_var->decl;
2778 empty_var->refcount = 1;
2779 empty_var->n_var_parts = 0;
2780 variable_was_changed (empty_var, NULL);
2782 else if (variable_different_p (old_var, new_var, true))
2784 variable_was_changed (new_var, NULL);
2787 /* Continue traversing the hash table. */
2791 /* Add variable *SLOT to the chain CHANGED_VARIABLES if it is not in hash
2795 emit_notes_for_differences_2 (void **slot, void *data)
2797 htab_t old_vars = (htab_t) data;
2798 variable old_var, new_var;
2800 new_var = *(variable *) slot;
2801 old_var = htab_find_with_hash (old_vars, new_var->decl,
2802 VARIABLE_HASH_VAL (new_var->decl));
2805 /* Variable has appeared. */
2806 variable_was_changed (new_var, NULL);
2809 /* Continue traversing the hash table. */
2813 /* Emit notes before INSN for differences between dataflow sets OLD_SET and
2817 emit_notes_for_differences (rtx insn, dataflow_set *old_set,
2818 dataflow_set *new_set)
2820 htab_traverse (old_set->vars, emit_notes_for_differences_1, new_set->vars);
2821 htab_traverse (new_set->vars, emit_notes_for_differences_2, old_set->vars);
2822 emit_notes_for_changes (insn, EMIT_NOTE_BEFORE_INSN);
2825 /* Emit the notes for changes of location parts in the basic block BB. */
2828 emit_notes_in_bb (basic_block bb)
2833 dataflow_set_init (&set, htab_elements (VTI (bb)->in.vars) + 3);
2834 dataflow_set_copy (&set, &VTI (bb)->in);
2836 for (i = 0; i < VTI (bb)->n_mos; i++)
2838 rtx insn = VTI (bb)->mos[i].insn;
2840 switch (VTI (bb)->mos[i].type)
2846 for (r = 0; r < FIRST_PSEUDO_REGISTER; r++)
2847 if (TEST_HARD_REG_BIT (call_used_reg_set, r))
2849 var_regno_delete (&set, r);
2851 emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
2857 rtx loc = VTI (bb)->mos[i].u.loc;
2859 enum var_init_status status = VAR_INIT_STATUS_UNINITIALIZED;
2860 if (! flag_var_tracking_uninit)
2861 status = VAR_INIT_STATUS_INITIALIZED;
2862 if (GET_CODE (loc) == REG)
2863 var_reg_set (&set, loc, status, NULL);
2865 var_mem_set (&set, loc, status, NULL);
2867 emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
2873 rtx loc = VTI (bb)->mos[i].u.loc;
2876 if (GET_CODE (PATTERN (insn)) == SET)
2877 set_src = SET_SRC (PATTERN (insn));
2878 else if (GET_CODE (PATTERN (insn)) == PARALLEL
2879 || GET_CODE (PATTERN (insn)) == SEQUENCE)
2882 for (j = XVECLEN (PATTERN (insn), 0) - 1; j >= 0; j--)
2883 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET
2884 && SET_DEST (XVECEXP (PATTERN (insn), 0, j)) == loc)
2885 set_src = SET_SRC (XVECEXP (PATTERN (insn), 0, j));
2889 var_reg_delete_and_set (&set, loc, true, VAR_INIT_STATUS_INITIALIZED,
2892 var_mem_delete_and_set (&set, loc, true, VAR_INIT_STATUS_INITIALIZED,
2895 emit_notes_for_changes (NEXT_INSN (insn), EMIT_NOTE_BEFORE_INSN);
2901 rtx loc = VTI (bb)->mos[i].u.loc;
2902 enum var_init_status src_status;
2905 src_status = find_src_status (&set, loc, VTI (bb)->mos[i].insn);
2906 set_src = find_src_set_src (&set, loc, VTI (bb)->mos[i].insn);
2909 var_reg_delete_and_set (&set, loc, false, src_status, set_src);
2911 var_mem_delete_and_set (&set, loc, false, src_status, set_src);
2913 emit_notes_for_changes (NEXT_INSN (insn), EMIT_NOTE_BEFORE_INSN);
2919 rtx loc = VTI (bb)->mos[i].u.loc;
2922 var_reg_delete (&set, loc, false);
2924 var_mem_delete (&set, loc, false);
2926 emit_notes_for_changes (insn, EMIT_NOTE_AFTER_INSN);
2932 rtx loc = VTI (bb)->mos[i].u.loc;
2935 var_reg_delete (&set, loc, true);
2937 var_mem_delete (&set, loc, true);
2939 emit_notes_for_changes (NEXT_INSN (insn), EMIT_NOTE_BEFORE_INSN);
2944 set.stack_adjust += VTI (bb)->mos[i].u.adjust;
2948 dataflow_set_destroy (&set);
2951 /* Emit notes for the whole function. */
2954 vt_emit_notes (void)
2957 dataflow_set *last_out;
2960 gcc_assert (!htab_elements (changed_variables));
2962 /* Enable emitting notes by functions (mainly by set_variable_part and
2963 delete_variable_part). */
2966 dataflow_set_init (&empty, 7);
2971 /* Emit the notes for changes of variable locations between two
2972 subsequent basic blocks. */
2973 emit_notes_for_differences (BB_HEAD (bb), last_out, &VTI (bb)->in);
2975 /* Emit the notes for the changes in the basic block itself. */
2976 emit_notes_in_bb (bb);
2978 last_out = &VTI (bb)->out;
2980 dataflow_set_destroy (&empty);
2984 /* If there is a declaration and offset associated with register/memory RTL
2985 assign declaration to *DECLP and offset to *OFFSETP, and return true. */
2988 vt_get_decl_and_offset (rtx rtl, tree *declp, HOST_WIDE_INT *offsetp)
2992 if (REG_ATTRS (rtl))
2994 *declp = REG_EXPR (rtl);
2995 *offsetp = REG_OFFSET (rtl);
2999 else if (MEM_P (rtl))
3001 if (MEM_ATTRS (rtl))
3003 *declp = MEM_EXPR (rtl);
3004 *offsetp = MEM_OFFSET (rtl) ? INTVAL (MEM_OFFSET (rtl)) : 0;
3011 /* Insert function parameters to IN and OUT sets of ENTRY_BLOCK. */
3014 vt_add_function_parameters (void)
3018 for (parm = DECL_ARGUMENTS (current_function_decl);
3019 parm; parm = TREE_CHAIN (parm))
3021 rtx decl_rtl = DECL_RTL_IF_SET (parm);
3022 rtx incoming = DECL_INCOMING_RTL (parm);
3024 HOST_WIDE_INT offset;
3027 if (TREE_CODE (parm) != PARM_DECL)
3030 if (!DECL_NAME (parm))
3033 if (!decl_rtl || !incoming)
3036 if (GET_MODE (decl_rtl) == BLKmode || GET_MODE (incoming) == BLKmode)
3039 if (!vt_get_decl_and_offset (incoming, &decl, &offset))
3040 if (!vt_get_decl_and_offset (decl_rtl, &decl, &offset))
3046 gcc_assert (parm == decl);
3048 out = &VTI (ENTRY_BLOCK_PTR)->out;
3050 if (REG_P (incoming))
3052 gcc_assert (REGNO (incoming) < FIRST_PSEUDO_REGISTER);
3053 attrs_list_insert (&out->regs[REGNO (incoming)],
3054 parm, offset, incoming);
3055 set_variable_part (out, incoming, parm, offset, VAR_INIT_STATUS_INITIALIZED,
3058 else if (MEM_P (incoming))
3059 set_variable_part (out, incoming, parm, offset, VAR_INIT_STATUS_INITIALIZED,
3064 /* Allocate and initialize the data structures for variable tracking
3065 and parse the RTL to get the micro operations. */
3068 vt_initialize (void)
3072 alloc_aux_for_blocks (sizeof (struct variable_tracking_info_def));
3077 HOST_WIDE_INT pre, post = 0;
3079 /* Count the number of micro operations. */
3080 VTI (bb)->n_mos = 0;
3081 for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
3082 insn = NEXT_INSN (insn))
3086 if (!frame_pointer_needed)
3088 insn_stack_adjust_offset_pre_post (insn, &pre, &post);
3094 note_uses (&PATTERN (insn), count_uses_1, insn);
3095 note_stores (PATTERN (insn), count_stores, insn);
3101 /* Add the micro-operations to the array. */
3102 VTI (bb)->mos = XNEWVEC (micro_operation, VTI (bb)->n_mos);
3103 VTI (bb)->n_mos = 0;
3104 for (insn = BB_HEAD (bb); insn != NEXT_INSN (BB_END (bb));
3105 insn = NEXT_INSN (insn))
3111 if (!frame_pointer_needed)
3113 insn_stack_adjust_offset_pre_post (insn, &pre, &post);
3116 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
3118 mo->type = MO_ADJUST;
3124 n1 = VTI (bb)->n_mos;
3125 note_uses (&PATTERN (insn), add_uses_1, insn);
3126 n2 = VTI (bb)->n_mos - 1;
3128 /* Order the MO_USEs to be before MO_USE_NO_VARs. */
3131 while (n1 < n2 && VTI (bb)->mos[n1].type == MO_USE)
3133 while (n1 < n2 && VTI (bb)->mos[n2].type == MO_USE_NO_VAR)
3139 sw = VTI (bb)->mos[n1];
3140 VTI (bb)->mos[n1] = VTI (bb)->mos[n2];
3141 VTI (bb)->mos[n2] = sw;
3147 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
3153 n1 = VTI (bb)->n_mos;
3154 /* This will record NEXT_INSN (insn), such that we can
3155 insert notes before it without worrying about any
3156 notes that MO_USEs might emit after the insn. */
3157 note_stores (PATTERN (insn), add_stores, insn);
3158 n2 = VTI (bb)->n_mos - 1;
3160 /* Order the MO_CLOBBERs to be before MO_SETs. */
3163 while (n1 < n2 && VTI (bb)->mos[n1].type == MO_CLOBBER)
3165 while (n1 < n2 && (VTI (bb)->mos[n2].type == MO_SET
3166 || VTI (bb)->mos[n2].type == MO_COPY))
3172 sw = VTI (bb)->mos[n1];
3173 VTI (bb)->mos[n1] = VTI (bb)->mos[n2];
3174 VTI (bb)->mos[n2] = sw;
3178 if (!frame_pointer_needed && post)
3180 micro_operation *mo = VTI (bb)->mos + VTI (bb)->n_mos++;
3182 mo->type = MO_ADJUST;
3183 mo->u.adjust = post;
3190 /* Init the IN and OUT sets. */
3193 VTI (bb)->visited = false;
3194 dataflow_set_init (&VTI (bb)->in, 7);
3195 dataflow_set_init (&VTI (bb)->out, 7);
3198 attrs_pool = create_alloc_pool ("attrs_def pool",
3199 sizeof (struct attrs_def), 1024);
3200 var_pool = create_alloc_pool ("variable_def pool",
3201 sizeof (struct variable_def), 64);
3202 loc_chain_pool = create_alloc_pool ("location_chain_def pool",
3203 sizeof (struct location_chain_def),
3205 changed_variables = htab_create (10, variable_htab_hash, variable_htab_eq,
3207 vt_add_function_parameters ();
3210 /* Free the data structures needed for variable tracking. */
3219 free (VTI (bb)->mos);
3224 dataflow_set_destroy (&VTI (bb)->in);
3225 dataflow_set_destroy (&VTI (bb)->out);
3227 free_aux_for_blocks ();
3228 free_alloc_pool (attrs_pool);
3229 free_alloc_pool (var_pool);
3230 free_alloc_pool (loc_chain_pool);
3231 htab_delete (changed_variables);
3234 /* The entry point to variable tracking pass. */
3237 variable_tracking_main (void)
3239 if (n_basic_blocks > 500 && n_edges / n_basic_blocks >= 20)
3242 mark_dfs_back_edges ();
3244 if (!frame_pointer_needed)
3246 if (!vt_stack_adjustments ())
3253 vt_find_locations ();
3256 if (dump_file && (dump_flags & TDF_DETAILS))
3258 dump_dataflow_sets ();
3259 dump_flow_info (dump_file, dump_flags);
3267 gate_handle_var_tracking (void)
3269 return (flag_var_tracking);
3274 struct tree_opt_pass pass_variable_tracking =
3276 "vartrack", /* name */
3277 gate_handle_var_tracking, /* gate */
3278 variable_tracking_main, /* execute */
3281 0, /* static_pass_number */
3282 TV_VAR_TRACKING, /* tv_id */
3283 0, /* properties_required */
3284 0, /* properties_provided */
3285 0, /* properties_destroyed */
3286 0, /* todo_flags_start */
3287 TODO_dump_func, /* todo_flags_finish */