1 /* Induction variable optimizations.
2 Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it
8 under the terms of the GNU General Public License as published by the
9 Free Software Foundation; either version 3, or (at your option) any
12 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* This pass tries to find the optimal set of induction variables for the loop.
22 It optimizes just the basic linear induction variables (although adding
23 support for other types should not be too hard). It includes the
24 optimizations commonly known as strength reduction, induction variable
25 coalescing and induction variable elimination. It does it in the
28 1) The interesting uses of induction variables are found. This includes
30 -- uses of induction variables in non-linear expressions
31 -- addresses of arrays
32 -- comparisons of induction variables
34 2) Candidates for the induction variables are found. This includes
36 -- old induction variables
37 -- the variables defined by expressions derived from the "interesting
40 3) The optimal (w.r. to a cost function) set of variables is chosen. The
41 cost function assigns a cost to sets of induction variables and consists
44 -- The use costs. Each of the interesting uses chooses the best induction
45 variable in the set and adds its cost to the sum. The cost reflects
46 the time spent on modifying the induction variables value to be usable
47 for the given purpose (adding base and offset for arrays, etc.).
48 -- The variable costs. Each of the variables has a cost assigned that
49 reflects the costs associated with incrementing the value of the
50 variable. The original variables are somewhat preferred.
51 -- The set cost. Depending on the size of the set, extra cost may be
52 added to reflect register pressure.
54 All the costs are defined in a machine-specific way, using the target
55 hooks and machine descriptions to determine them.
57 4) The trees are transformed to use the new variables, the dead code is
60 All of this is done loop by loop. Doing it globally is theoretically
61 possible, it might give a better performance and it might enable us
62 to decide costs more precisely, but getting all the interactions right
63 would be complicated. */
67 #include "coretypes.h"
71 #include "basic-block.h"
73 #include "tree-pretty-print.h"
74 #include "gimple-pretty-print.h"
75 #include "tree-flow.h"
76 #include "tree-dump.h"
79 #include "tree-pass.h"
81 #include "insn-config.h"
83 #include "pointer-set.h"
85 #include "tree-chrec.h"
86 #include "tree-scalar-evolution.h"
89 #include "langhooks.h"
90 #include "tree-affine.h"
92 #include "tree-inline.h"
93 #include "tree-ssa-propagate.h"
95 /* FIXME: add_cost and zero_cost defined in exprmed.h conflict with local uses.
101 /* FIXME: Expressions are expanded to RTL in this pass to determine the
102 cost of different addressing modes. This should be moved to a TBD
103 interface between the GIMPLE and RTL worlds. */
106 /* The infinite cost. */
107 #define INFTY 10000000
109 #define AVG_LOOP_NITER(LOOP) 5
111 /* Returns the expected number of loop iterations for LOOP.
112 The average trip count is computed from profile data if it
115 static inline HOST_WIDE_INT
116 avg_loop_niter (struct loop *loop)
118 HOST_WIDE_INT niter = max_stmt_executions_int (loop, false);
120 return AVG_LOOP_NITER (loop);
125 /* Representation of the induction variable. */
128 tree base; /* Initial value of the iv. */
129 tree base_object; /* A memory object to that the induction variable points. */
130 tree step; /* Step of the iv (constant only). */
131 tree ssa_name; /* The ssa name with the value. */
132 bool biv_p; /* Is it a biv? */
133 bool have_use_for; /* Do we already have a use for it? */
134 unsigned use_id; /* The identifier in the use if it is the case. */
137 /* Per-ssa version information (induction variable descriptions, etc.). */
140 tree name; /* The ssa name. */
141 struct iv *iv; /* Induction variable description. */
142 bool has_nonlin_use; /* For a loop-level invariant, whether it is used in
143 an expression that is not an induction variable. */
144 bool preserve_biv; /* For the original biv, whether to preserve it. */
145 unsigned inv_id; /* Id of an invariant. */
151 USE_NONLINEAR_EXPR, /* Use in a nonlinear expression. */
152 USE_ADDRESS, /* Use in an address. */
153 USE_COMPARE /* Use is a compare. */
156 /* Cost of a computation. */
159 int cost; /* The runtime cost. */
160 unsigned complexity; /* The estimate of the complexity of the code for
161 the computation (in no concrete units --
162 complexity field should be larger for more
163 complex expressions and addressing modes). */
166 static const comp_cost zero_cost = {0, 0};
167 static const comp_cost infinite_cost = {INFTY, INFTY};
169 /* The candidate - cost pair. */
172 struct iv_cand *cand; /* The candidate. */
173 comp_cost cost; /* The cost. */
174 bitmap depends_on; /* The list of invariants that have to be
176 tree value; /* For final value elimination, the expression for
177 the final value of the iv. For iv elimination,
178 the new bound to compare with. */
179 int inv_expr_id; /* Loop invariant expression id. */
185 unsigned id; /* The id of the use. */
186 enum use_type type; /* Type of the use. */
187 struct iv *iv; /* The induction variable it is based on. */
188 gimple stmt; /* Statement in that it occurs. */
189 tree *op_p; /* The place where it occurs. */
190 bitmap related_cands; /* The set of "related" iv candidates, plus the common
193 unsigned n_map_members; /* Number of candidates in the cost_map list. */
194 struct cost_pair *cost_map;
195 /* The costs wrto the iv candidates. */
197 struct iv_cand *selected;
198 /* The selected candidate. */
201 /* The position where the iv is computed. */
204 IP_NORMAL, /* At the end, just before the exit condition. */
205 IP_END, /* At the end of the latch block. */
206 IP_BEFORE_USE, /* Immediately before a specific use. */
207 IP_AFTER_USE, /* Immediately after a specific use. */
208 IP_ORIGINAL /* The original biv. */
211 /* The induction variable candidate. */
214 unsigned id; /* The number of the candidate. */
215 bool important; /* Whether this is an "important" candidate, i.e. such
216 that it should be considered by all uses. */
217 ENUM_BITFIELD(iv_position) pos : 8; /* Where it is computed. */
218 gimple incremented_at;/* For original biv, the statement where it is
220 tree var_before; /* The variable used for it before increment. */
221 tree var_after; /* The variable used for it after increment. */
222 struct iv *iv; /* The value of the candidate. NULL for
223 "pseudocandidate" used to indicate the possibility
224 to replace the final value of an iv by direct
225 computation of the value. */
226 unsigned cost; /* Cost of the candidate. */
227 unsigned cost_step; /* Cost of the candidate's increment operation. */
228 struct iv_use *ainc_use; /* For IP_{BEFORE,AFTER}_USE candidates, the place
229 where it is incremented. */
230 bitmap depends_on; /* The list of invariants that are used in step of the
234 /* Loop invariant expression hashtable entry. */
235 struct iv_inv_expr_ent
242 /* The data used by the induction variable optimizations. */
244 typedef struct iv_use *iv_use_p;
246 DEF_VEC_ALLOC_P(iv_use_p,heap);
248 typedef struct iv_cand *iv_cand_p;
249 DEF_VEC_P(iv_cand_p);
250 DEF_VEC_ALLOC_P(iv_cand_p,heap);
254 /* The currently optimized loop. */
255 struct loop *current_loop;
257 /* Numbers of iterations for all exits of the current loop. */
258 struct pointer_map_t *niters;
260 /* Number of registers used in it. */
263 /* The size of version_info array allocated. */
264 unsigned version_info_size;
266 /* The array of information for the ssa names. */
267 struct version_info *version_info;
269 /* The hashtable of loop invariant expressions created
273 /* Loop invariant expression id. */
276 /* The bitmap of indices in version_info whose value was changed. */
279 /* The uses of induction variables. */
280 VEC(iv_use_p,heap) *iv_uses;
282 /* The candidates. */
283 VEC(iv_cand_p,heap) *iv_candidates;
285 /* A bitmap of important candidates. */
286 bitmap important_candidates;
288 /* The maximum invariant id. */
291 /* Whether to consider just related and important candidates when replacing a
293 bool consider_all_candidates;
295 /* Are we optimizing for speed? */
298 /* Whether the loop body includes any function calls. */
299 bool body_includes_call;
302 /* An assignment of iv candidates to uses. */
306 /* The number of uses covered by the assignment. */
309 /* Number of uses that cannot be expressed by the candidates in the set. */
312 /* Candidate assigned to a use, together with the related costs. */
313 struct cost_pair **cand_for_use;
315 /* Number of times each candidate is used. */
316 unsigned *n_cand_uses;
318 /* The candidates used. */
321 /* The number of candidates in the set. */
324 /* Total number of registers needed. */
327 /* Total cost of expressing uses. */
328 comp_cost cand_use_cost;
330 /* Total cost of candidates. */
333 /* Number of times each invariant is used. */
334 unsigned *n_invariant_uses;
336 /* The array holding the number of uses of each loop
337 invariant expressions created by ivopt. */
338 unsigned *used_inv_expr;
340 /* The number of created loop invariants. */
341 unsigned num_used_inv_expr;
343 /* Total cost of the assignment. */
347 /* Difference of two iv candidate assignments. */
354 /* An old assignment (for rollback purposes). */
355 struct cost_pair *old_cp;
357 /* A new assignment. */
358 struct cost_pair *new_cp;
360 /* Next change in the list. */
361 struct iv_ca_delta *next_change;
364 /* Bound on number of candidates below that all candidates are considered. */
366 #define CONSIDER_ALL_CANDIDATES_BOUND \
367 ((unsigned) PARAM_VALUE (PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND))
369 /* If there are more iv occurrences, we just give up (it is quite unlikely that
370 optimizing such a loop would help, and it would take ages). */
372 #define MAX_CONSIDERED_USES \
373 ((unsigned) PARAM_VALUE (PARAM_IV_MAX_CONSIDERED_USES))
375 /* If there are at most this number of ivs in the set, try removing unnecessary
376 ivs from the set always. */
378 #define ALWAYS_PRUNE_CAND_SET_BOUND \
379 ((unsigned) PARAM_VALUE (PARAM_IV_ALWAYS_PRUNE_CAND_SET_BOUND))
381 /* The list of trees for that the decl_rtl field must be reset is stored
384 static VEC(tree,heap) *decl_rtl_to_reset;
386 static comp_cost force_expr_to_var_cost (tree, bool);
388 /* Number of uses recorded in DATA. */
390 static inline unsigned
391 n_iv_uses (struct ivopts_data *data)
393 return VEC_length (iv_use_p, data->iv_uses);
396 /* Ith use recorded in DATA. */
398 static inline struct iv_use *
399 iv_use (struct ivopts_data *data, unsigned i)
401 return VEC_index (iv_use_p, data->iv_uses, i);
404 /* Number of candidates recorded in DATA. */
406 static inline unsigned
407 n_iv_cands (struct ivopts_data *data)
409 return VEC_length (iv_cand_p, data->iv_candidates);
412 /* Ith candidate recorded in DATA. */
414 static inline struct iv_cand *
415 iv_cand (struct ivopts_data *data, unsigned i)
417 return VEC_index (iv_cand_p, data->iv_candidates, i);
420 /* The single loop exit if it dominates the latch, NULL otherwise. */
423 single_dom_exit (struct loop *loop)
425 edge exit = single_exit (loop);
430 if (!just_once_each_iteration_p (loop, exit->src))
436 /* Dumps information about the induction variable IV to FILE. */
438 extern void dump_iv (FILE *, struct iv *);
440 dump_iv (FILE *file, struct iv *iv)
444 fprintf (file, "ssa name ");
445 print_generic_expr (file, iv->ssa_name, TDF_SLIM);
446 fprintf (file, "\n");
449 fprintf (file, " type ");
450 print_generic_expr (file, TREE_TYPE (iv->base), TDF_SLIM);
451 fprintf (file, "\n");
455 fprintf (file, " base ");
456 print_generic_expr (file, iv->base, TDF_SLIM);
457 fprintf (file, "\n");
459 fprintf (file, " step ");
460 print_generic_expr (file, iv->step, TDF_SLIM);
461 fprintf (file, "\n");
465 fprintf (file, " invariant ");
466 print_generic_expr (file, iv->base, TDF_SLIM);
467 fprintf (file, "\n");
472 fprintf (file, " base object ");
473 print_generic_expr (file, iv->base_object, TDF_SLIM);
474 fprintf (file, "\n");
478 fprintf (file, " is a biv\n");
481 /* Dumps information about the USE to FILE. */
483 extern void dump_use (FILE *, struct iv_use *);
485 dump_use (FILE *file, struct iv_use *use)
487 fprintf (file, "use %d\n", use->id);
491 case USE_NONLINEAR_EXPR:
492 fprintf (file, " generic\n");
496 fprintf (file, " address\n");
500 fprintf (file, " compare\n");
507 fprintf (file, " in statement ");
508 print_gimple_stmt (file, use->stmt, 0, 0);
509 fprintf (file, "\n");
511 fprintf (file, " at position ");
513 print_generic_expr (file, *use->op_p, TDF_SLIM);
514 fprintf (file, "\n");
516 dump_iv (file, use->iv);
518 if (use->related_cands)
520 fprintf (file, " related candidates ");
521 dump_bitmap (file, use->related_cands);
525 /* Dumps information about the uses to FILE. */
527 extern void dump_uses (FILE *, struct ivopts_data *);
529 dump_uses (FILE *file, struct ivopts_data *data)
534 for (i = 0; i < n_iv_uses (data); i++)
536 use = iv_use (data, i);
538 dump_use (file, use);
539 fprintf (file, "\n");
543 /* Dumps information about induction variable candidate CAND to FILE. */
545 extern void dump_cand (FILE *, struct iv_cand *);
547 dump_cand (FILE *file, struct iv_cand *cand)
549 struct iv *iv = cand->iv;
551 fprintf (file, "candidate %d%s\n",
552 cand->id, cand->important ? " (important)" : "");
554 if (cand->depends_on)
556 fprintf (file, " depends on ");
557 dump_bitmap (file, cand->depends_on);
562 fprintf (file, " final value replacement\n");
566 if (cand->var_before)
568 fprintf (file, " var_before ");
569 print_generic_expr (file, cand->var_before, TDF_SLIM);
570 fprintf (file, "\n");
574 fprintf (file, " var_after ");
575 print_generic_expr (file, cand->var_after, TDF_SLIM);
576 fprintf (file, "\n");
582 fprintf (file, " incremented before exit test\n");
586 fprintf (file, " incremented before use %d\n", cand->ainc_use->id);
590 fprintf (file, " incremented after use %d\n", cand->ainc_use->id);
594 fprintf (file, " incremented at end\n");
598 fprintf (file, " original biv\n");
605 /* Returns the info for ssa version VER. */
607 static inline struct version_info *
608 ver_info (struct ivopts_data *data, unsigned ver)
610 return data->version_info + ver;
613 /* Returns the info for ssa name NAME. */
615 static inline struct version_info *
616 name_info (struct ivopts_data *data, tree name)
618 return ver_info (data, SSA_NAME_VERSION (name));
621 /* Returns true if STMT is after the place where the IP_NORMAL ivs will be
625 stmt_after_ip_normal_pos (struct loop *loop, gimple stmt)
627 basic_block bb = ip_normal_pos (loop), sbb = gimple_bb (stmt);
631 if (sbb == loop->latch)
637 return stmt == last_stmt (bb);
640 /* Returns true if STMT if after the place where the original induction
641 variable CAND is incremented. If TRUE_IF_EQUAL is set, we return true
642 if the positions are identical. */
645 stmt_after_inc_pos (struct iv_cand *cand, gimple stmt, bool true_if_equal)
647 basic_block cand_bb = gimple_bb (cand->incremented_at);
648 basic_block stmt_bb = gimple_bb (stmt);
650 if (!dominated_by_p (CDI_DOMINATORS, stmt_bb, cand_bb))
653 if (stmt_bb != cand_bb)
657 && gimple_uid (stmt) == gimple_uid (cand->incremented_at))
659 return gimple_uid (stmt) > gimple_uid (cand->incremented_at);
662 /* Returns true if STMT if after the place where the induction variable
663 CAND is incremented in LOOP. */
666 stmt_after_increment (struct loop *loop, struct iv_cand *cand, gimple stmt)
674 return stmt_after_ip_normal_pos (loop, stmt);
678 return stmt_after_inc_pos (cand, stmt, false);
681 return stmt_after_inc_pos (cand, stmt, true);
688 /* Returns true if EXP is a ssa name that occurs in an abnormal phi node. */
691 abnormal_ssa_name_p (tree exp)
696 if (TREE_CODE (exp) != SSA_NAME)
699 return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) != 0;
702 /* Returns false if BASE or INDEX contains a ssa name that occurs in an
703 abnormal phi node. Callback for for_each_index. */
706 idx_contains_abnormal_ssa_name_p (tree base, tree *index,
707 void *data ATTRIBUTE_UNUSED)
709 if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
711 if (abnormal_ssa_name_p (TREE_OPERAND (base, 2)))
713 if (abnormal_ssa_name_p (TREE_OPERAND (base, 3)))
717 return !abnormal_ssa_name_p (*index);
720 /* Returns true if EXPR contains a ssa name that occurs in an
721 abnormal phi node. */
724 contains_abnormal_ssa_name_p (tree expr)
727 enum tree_code_class codeclass;
732 code = TREE_CODE (expr);
733 codeclass = TREE_CODE_CLASS (code);
735 if (code == SSA_NAME)
736 return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr) != 0;
738 if (code == INTEGER_CST
739 || is_gimple_min_invariant (expr))
742 if (code == ADDR_EXPR)
743 return !for_each_index (&TREE_OPERAND (expr, 0),
744 idx_contains_abnormal_ssa_name_p,
747 if (code == COND_EXPR)
748 return contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0))
749 || contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1))
750 || contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 2));
756 if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 1)))
761 if (contains_abnormal_ssa_name_p (TREE_OPERAND (expr, 0)))
773 /* Returns tree describing number of iterations determined from
774 EXIT of DATA->current_loop, or NULL if something goes wrong. */
777 niter_for_exit (struct ivopts_data *data, edge exit,
778 struct tree_niter_desc **desc_p)
780 struct tree_niter_desc* desc = NULL;
786 data->niters = pointer_map_create ();
790 slot = pointer_map_contains (data->niters, exit);
794 /* Try to determine number of iterations. We must know it
795 unconditionally (i.e., without possibility of # of iterations
796 being zero). Also, we cannot safely work with ssa names that
797 appear in phi nodes on abnormal edges, so that we do not create
798 overlapping life ranges for them (PR 27283). */
799 desc = XNEW (struct tree_niter_desc);
800 if (number_of_iterations_exit (data->current_loop,
802 && integer_zerop (desc->may_be_zero)
803 && !contains_abnormal_ssa_name_p (desc->niter))
809 slot = pointer_map_insert (data->niters, exit);
813 niter = ((struct tree_niter_desc *) *slot)->niter;
816 *desc_p = (struct tree_niter_desc *) *slot;
820 /* Returns tree describing number of iterations determined from
821 single dominating exit of DATA->current_loop, or NULL if something
825 niter_for_single_dom_exit (struct ivopts_data *data)
827 edge exit = single_dom_exit (data->current_loop);
832 return niter_for_exit (data, exit, NULL);
835 /* Hash table equality function for expressions. */
838 htab_inv_expr_eq (const void *ent1, const void *ent2)
840 const struct iv_inv_expr_ent *expr1 =
841 (const struct iv_inv_expr_ent *)ent1;
842 const struct iv_inv_expr_ent *expr2 =
843 (const struct iv_inv_expr_ent *)ent2;
845 return expr1->hash == expr2->hash
846 && operand_equal_p (expr1->expr, expr2->expr, 0);
849 /* Hash function for loop invariant expressions. */
852 htab_inv_expr_hash (const void *ent)
854 const struct iv_inv_expr_ent *expr =
855 (const struct iv_inv_expr_ent *)ent;
859 /* Initializes data structures used by the iv optimization pass, stored
863 tree_ssa_iv_optimize_init (struct ivopts_data *data)
865 data->version_info_size = 2 * num_ssa_names;
866 data->version_info = XCNEWVEC (struct version_info, data->version_info_size);
867 data->relevant = BITMAP_ALLOC (NULL);
868 data->important_candidates = BITMAP_ALLOC (NULL);
869 data->max_inv_id = 0;
871 data->iv_uses = VEC_alloc (iv_use_p, heap, 20);
872 data->iv_candidates = VEC_alloc (iv_cand_p, heap, 20);
873 data->inv_expr_tab = htab_create (10, htab_inv_expr_hash,
874 htab_inv_expr_eq, free);
875 data->inv_expr_id = 0;
876 decl_rtl_to_reset = VEC_alloc (tree, heap, 20);
879 /* Returns a memory object to that EXPR points. In case we are able to
880 determine that it does not point to any such object, NULL is returned. */
883 determine_base_object (tree expr)
885 enum tree_code code = TREE_CODE (expr);
888 /* If this is a pointer casted to any type, we need to determine
889 the base object for the pointer; so handle conversions before
890 throwing away non-pointer expressions. */
891 if (CONVERT_EXPR_P (expr))
892 return determine_base_object (TREE_OPERAND (expr, 0));
894 if (!POINTER_TYPE_P (TREE_TYPE (expr)))
903 obj = TREE_OPERAND (expr, 0);
904 base = get_base_address (obj);
909 if (TREE_CODE (base) == MEM_REF)
910 return determine_base_object (TREE_OPERAND (base, 0));
912 return fold_convert (ptr_type_node,
913 build_fold_addr_expr (base));
915 case POINTER_PLUS_EXPR:
916 return determine_base_object (TREE_OPERAND (expr, 0));
920 /* Pointer addition is done solely using POINTER_PLUS_EXPR. */
924 return fold_convert (ptr_type_node, expr);
928 /* Allocates an induction variable with given initial value BASE and step STEP
932 alloc_iv (tree base, tree step)
934 struct iv *iv = XCNEW (struct iv);
935 gcc_assert (step != NULL_TREE);
938 iv->base_object = determine_base_object (base);
941 iv->have_use_for = false;
943 iv->ssa_name = NULL_TREE;
948 /* Sets STEP and BASE for induction variable IV. */
951 set_iv (struct ivopts_data *data, tree iv, tree base, tree step)
953 struct version_info *info = name_info (data, iv);
955 gcc_assert (!info->iv);
957 bitmap_set_bit (data->relevant, SSA_NAME_VERSION (iv));
958 info->iv = alloc_iv (base, step);
959 info->iv->ssa_name = iv;
962 /* Finds induction variable declaration for VAR. */
965 get_iv (struct ivopts_data *data, tree var)
968 tree type = TREE_TYPE (var);
970 if (!POINTER_TYPE_P (type)
971 && !INTEGRAL_TYPE_P (type))
974 if (!name_info (data, var)->iv)
976 bb = gimple_bb (SSA_NAME_DEF_STMT (var));
979 || !flow_bb_inside_loop_p (data->current_loop, bb))
980 set_iv (data, var, var, build_int_cst (type, 0));
983 return name_info (data, var)->iv;
986 /* Determines the step of a biv defined in PHI. Returns NULL if PHI does
987 not define a simple affine biv with nonzero step. */
990 determine_biv_step (gimple phi)
992 struct loop *loop = gimple_bb (phi)->loop_father;
993 tree name = PHI_RESULT (phi);
996 if (!is_gimple_reg (name))
999 if (!simple_iv (loop, loop, name, &iv, true))
1002 return integer_zerop (iv.step) ? NULL_TREE : iv.step;
1005 /* Finds basic ivs. */
1008 find_bivs (struct ivopts_data *data)
1011 tree step, type, base;
1013 struct loop *loop = data->current_loop;
1014 gimple_stmt_iterator psi;
1016 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
1018 phi = gsi_stmt (psi);
1020 if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)))
1023 step = determine_biv_step (phi);
1027 base = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop));
1028 base = expand_simple_operations (base);
1029 if (contains_abnormal_ssa_name_p (base)
1030 || contains_abnormal_ssa_name_p (step))
1033 type = TREE_TYPE (PHI_RESULT (phi));
1034 base = fold_convert (type, base);
1037 if (POINTER_TYPE_P (type))
1038 step = fold_convert (sizetype, step);
1040 step = fold_convert (type, step);
1043 set_iv (data, PHI_RESULT (phi), base, step);
1050 /* Marks basic ivs. */
1053 mark_bivs (struct ivopts_data *data)
1057 struct iv *iv, *incr_iv;
1058 struct loop *loop = data->current_loop;
1059 basic_block incr_bb;
1060 gimple_stmt_iterator psi;
1062 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
1064 phi = gsi_stmt (psi);
1066 iv = get_iv (data, PHI_RESULT (phi));
1070 var = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (loop));
1071 incr_iv = get_iv (data, var);
1075 /* If the increment is in the subloop, ignore it. */
1076 incr_bb = gimple_bb (SSA_NAME_DEF_STMT (var));
1077 if (incr_bb->loop_father != data->current_loop
1078 || (incr_bb->flags & BB_IRREDUCIBLE_LOOP))
1082 incr_iv->biv_p = true;
1086 /* Checks whether STMT defines a linear induction variable and stores its
1087 parameters to IV. */
1090 find_givs_in_stmt_scev (struct ivopts_data *data, gimple stmt, affine_iv *iv)
1093 struct loop *loop = data->current_loop;
1095 iv->base = NULL_TREE;
1096 iv->step = NULL_TREE;
1098 if (gimple_code (stmt) != GIMPLE_ASSIGN)
1101 lhs = gimple_assign_lhs (stmt);
1102 if (TREE_CODE (lhs) != SSA_NAME)
1105 if (!simple_iv (loop, loop_containing_stmt (stmt), lhs, iv, true))
1107 iv->base = expand_simple_operations (iv->base);
1109 if (contains_abnormal_ssa_name_p (iv->base)
1110 || contains_abnormal_ssa_name_p (iv->step))
1113 /* If STMT could throw, then do not consider STMT as defining a GIV.
1114 While this will suppress optimizations, we can not safely delete this
1115 GIV and associated statements, even if it appears it is not used. */
1116 if (stmt_could_throw_p (stmt))
1122 /* Finds general ivs in statement STMT. */
1125 find_givs_in_stmt (struct ivopts_data *data, gimple stmt)
1129 if (!find_givs_in_stmt_scev (data, stmt, &iv))
1132 set_iv (data, gimple_assign_lhs (stmt), iv.base, iv.step);
1135 /* Finds general ivs in basic block BB. */
1138 find_givs_in_bb (struct ivopts_data *data, basic_block bb)
1140 gimple_stmt_iterator bsi;
1142 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
1143 find_givs_in_stmt (data, gsi_stmt (bsi));
1146 /* Finds general ivs. */
1149 find_givs (struct ivopts_data *data)
1151 struct loop *loop = data->current_loop;
1152 basic_block *body = get_loop_body_in_dom_order (loop);
1155 for (i = 0; i < loop->num_nodes; i++)
1156 find_givs_in_bb (data, body[i]);
1160 /* For each ssa name defined in LOOP determines whether it is an induction
1161 variable and if so, its initial value and step. */
1164 find_induction_variables (struct ivopts_data *data)
1169 if (!find_bivs (data))
1175 if (dump_file && (dump_flags & TDF_DETAILS))
1177 tree niter = niter_for_single_dom_exit (data);
1181 fprintf (dump_file, " number of iterations ");
1182 print_generic_expr (dump_file, niter, TDF_SLIM);
1183 fprintf (dump_file, "\n\n");
1186 fprintf (dump_file, "Induction variables:\n\n");
1188 EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
1190 if (ver_info (data, i)->iv)
1191 dump_iv (dump_file, ver_info (data, i)->iv);
1198 /* Records a use of type USE_TYPE at *USE_P in STMT whose value is IV. */
1200 static struct iv_use *
1201 record_use (struct ivopts_data *data, tree *use_p, struct iv *iv,
1202 gimple stmt, enum use_type use_type)
1204 struct iv_use *use = XCNEW (struct iv_use);
1206 use->id = n_iv_uses (data);
1207 use->type = use_type;
1211 use->related_cands = BITMAP_ALLOC (NULL);
1213 /* To avoid showing ssa name in the dumps, if it was not reset by the
1215 iv->ssa_name = NULL_TREE;
1217 if (dump_file && (dump_flags & TDF_DETAILS))
1218 dump_use (dump_file, use);
1220 VEC_safe_push (iv_use_p, heap, data->iv_uses, use);
1225 /* Checks whether OP is a loop-level invariant and if so, records it.
1226 NONLINEAR_USE is true if the invariant is used in a way we do not
1227 handle specially. */
1230 record_invariant (struct ivopts_data *data, tree op, bool nonlinear_use)
1233 struct version_info *info;
1235 if (TREE_CODE (op) != SSA_NAME
1236 || !is_gimple_reg (op))
1239 bb = gimple_bb (SSA_NAME_DEF_STMT (op));
1241 && flow_bb_inside_loop_p (data->current_loop, bb))
1244 info = name_info (data, op);
1246 info->has_nonlin_use |= nonlinear_use;
1248 info->inv_id = ++data->max_inv_id;
1249 bitmap_set_bit (data->relevant, SSA_NAME_VERSION (op));
1252 /* Checks whether the use OP is interesting and if so, records it. */
1254 static struct iv_use *
1255 find_interesting_uses_op (struct ivopts_data *data, tree op)
1262 if (TREE_CODE (op) != SSA_NAME)
1265 iv = get_iv (data, op);
1269 if (iv->have_use_for)
1271 use = iv_use (data, iv->use_id);
1273 gcc_assert (use->type == USE_NONLINEAR_EXPR);
1277 if (integer_zerop (iv->step))
1279 record_invariant (data, op, true);
1282 iv->have_use_for = true;
1284 civ = XNEW (struct iv);
1287 stmt = SSA_NAME_DEF_STMT (op);
1288 gcc_assert (gimple_code (stmt) == GIMPLE_PHI
1289 || is_gimple_assign (stmt));
1291 use = record_use (data, NULL, civ, stmt, USE_NONLINEAR_EXPR);
1292 iv->use_id = use->id;
1297 /* Given a condition in statement STMT, checks whether it is a compare
1298 of an induction variable and an invariant. If this is the case,
1299 CONTROL_VAR is set to location of the iv, BOUND to the location of
1300 the invariant, IV_VAR and IV_BOUND are set to the corresponding
1301 induction variable descriptions, and true is returned. If this is not
1302 the case, CONTROL_VAR and BOUND are set to the arguments of the
1303 condition and false is returned. */
1306 extract_cond_operands (struct ivopts_data *data, gimple stmt,
1307 tree **control_var, tree **bound,
1308 struct iv **iv_var, struct iv **iv_bound)
1310 /* The objects returned when COND has constant operands. */
1311 static struct iv const_iv;
1313 tree *op0 = &zero, *op1 = &zero, *tmp_op;
1314 struct iv *iv0 = &const_iv, *iv1 = &const_iv, *tmp_iv;
1317 if (gimple_code (stmt) == GIMPLE_COND)
1319 op0 = gimple_cond_lhs_ptr (stmt);
1320 op1 = gimple_cond_rhs_ptr (stmt);
1324 op0 = gimple_assign_rhs1_ptr (stmt);
1325 op1 = gimple_assign_rhs2_ptr (stmt);
1328 zero = integer_zero_node;
1329 const_iv.step = integer_zero_node;
1331 if (TREE_CODE (*op0) == SSA_NAME)
1332 iv0 = get_iv (data, *op0);
1333 if (TREE_CODE (*op1) == SSA_NAME)
1334 iv1 = get_iv (data, *op1);
1336 /* Exactly one of the compared values must be an iv, and the other one must
1341 if (integer_zerop (iv0->step))
1343 /* Control variable may be on the other side. */
1344 tmp_op = op0; op0 = op1; op1 = tmp_op;
1345 tmp_iv = iv0; iv0 = iv1; iv1 = tmp_iv;
1347 ret = !integer_zerop (iv0->step) && integer_zerop (iv1->step);
1351 *control_var = op0;;
1362 /* Checks whether the condition in STMT is interesting and if so,
1366 find_interesting_uses_cond (struct ivopts_data *data, gimple stmt)
1368 tree *var_p, *bound_p;
1369 struct iv *var_iv, *civ;
1371 if (!extract_cond_operands (data, stmt, &var_p, &bound_p, &var_iv, NULL))
1373 find_interesting_uses_op (data, *var_p);
1374 find_interesting_uses_op (data, *bound_p);
1378 civ = XNEW (struct iv);
1380 record_use (data, NULL, civ, stmt, USE_COMPARE);
1383 /* Returns true if expression EXPR is obviously invariant in LOOP,
1384 i.e. if all its operands are defined outside of the LOOP. LOOP
1385 should not be the function body. */
1388 expr_invariant_in_loop_p (struct loop *loop, tree expr)
1393 gcc_assert (loop_depth (loop) > 0);
1395 if (is_gimple_min_invariant (expr))
1398 if (TREE_CODE (expr) == SSA_NAME)
1400 def_bb = gimple_bb (SSA_NAME_DEF_STMT (expr));
1402 && flow_bb_inside_loop_p (loop, def_bb))
1411 len = TREE_OPERAND_LENGTH (expr);
1412 for (i = 0; i < len; i++)
1413 if (!expr_invariant_in_loop_p (loop, TREE_OPERAND (expr, i)))
1419 /* Returns true if statement STMT is obviously invariant in LOOP,
1420 i.e. if all its operands on the RHS are defined outside of the LOOP.
1421 LOOP should not be the function body. */
1424 stmt_invariant_in_loop_p (struct loop *loop, gimple stmt)
1429 gcc_assert (loop_depth (loop) > 0);
1431 lhs = gimple_get_lhs (stmt);
1432 for (i = 0; i < gimple_num_ops (stmt); i++)
1434 tree op = gimple_op (stmt, i);
1435 if (op != lhs && !expr_invariant_in_loop_p (loop, op))
1442 /* Cumulates the steps of indices into DATA and replaces their values with the
1443 initial ones. Returns false when the value of the index cannot be determined.
1444 Callback for for_each_index. */
1446 struct ifs_ivopts_data
1448 struct ivopts_data *ivopts_data;
1454 idx_find_step (tree base, tree *idx, void *data)
1456 struct ifs_ivopts_data *dta = (struct ifs_ivopts_data *) data;
1458 tree step, iv_base, iv_step, lbound, off;
1459 struct loop *loop = dta->ivopts_data->current_loop;
1461 /* If base is a component ref, require that the offset of the reference
1463 if (TREE_CODE (base) == COMPONENT_REF)
1465 off = component_ref_field_offset (base);
1466 return expr_invariant_in_loop_p (loop, off);
1469 /* If base is array, first check whether we will be able to move the
1470 reference out of the loop (in order to take its address in strength
1471 reduction). In order for this to work we need both lower bound
1472 and step to be loop invariants. */
1473 if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
1475 /* Moreover, for a range, the size needs to be invariant as well. */
1476 if (TREE_CODE (base) == ARRAY_RANGE_REF
1477 && !expr_invariant_in_loop_p (loop, TYPE_SIZE (TREE_TYPE (base))))
1480 step = array_ref_element_size (base);
1481 lbound = array_ref_low_bound (base);
1483 if (!expr_invariant_in_loop_p (loop, step)
1484 || !expr_invariant_in_loop_p (loop, lbound))
1488 if (TREE_CODE (*idx) != SSA_NAME)
1491 iv = get_iv (dta->ivopts_data, *idx);
1495 /* XXX We produce for a base of *D42 with iv->base being &x[0]
1496 *&x[0], which is not folded and does not trigger the
1497 ARRAY_REF path below. */
1500 if (integer_zerop (iv->step))
1503 if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
1505 step = array_ref_element_size (base);
1507 /* We only handle addresses whose step is an integer constant. */
1508 if (TREE_CODE (step) != INTEGER_CST)
1512 /* The step for pointer arithmetics already is 1 byte. */
1513 step = size_one_node;
1517 if (!convert_affine_scev (dta->ivopts_data->current_loop,
1518 sizetype, &iv_base, &iv_step, dta->stmt,
1521 /* The index might wrap. */
1525 step = fold_build2 (MULT_EXPR, sizetype, step, iv_step);
1526 dta->step = fold_build2 (PLUS_EXPR, sizetype, dta->step, step);
1531 /* Records use in index IDX. Callback for for_each_index. Ivopts data
1532 object is passed to it in DATA. */
1535 idx_record_use (tree base, tree *idx,
1538 struct ivopts_data *data = (struct ivopts_data *) vdata;
1539 find_interesting_uses_op (data, *idx);
1540 if (TREE_CODE (base) == ARRAY_REF || TREE_CODE (base) == ARRAY_RANGE_REF)
1542 find_interesting_uses_op (data, array_ref_element_size (base));
1543 find_interesting_uses_op (data, array_ref_low_bound (base));
1548 /* If we can prove that TOP = cst * BOT for some constant cst,
1549 store cst to MUL and return true. Otherwise return false.
1550 The returned value is always sign-extended, regardless of the
1551 signedness of TOP and BOT. */
1554 constant_multiple_of (tree top, tree bot, double_int *mul)
1557 enum tree_code code;
1558 double_int res, p0, p1;
1559 unsigned precision = TYPE_PRECISION (TREE_TYPE (top));
1564 if (operand_equal_p (top, bot, 0))
1566 *mul = double_int_one;
1570 code = TREE_CODE (top);
1574 mby = TREE_OPERAND (top, 1);
1575 if (TREE_CODE (mby) != INTEGER_CST)
1578 if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &res))
1581 *mul = double_int_sext (double_int_mul (res, tree_to_double_int (mby)),
1587 if (!constant_multiple_of (TREE_OPERAND (top, 0), bot, &p0)
1588 || !constant_multiple_of (TREE_OPERAND (top, 1), bot, &p1))
1591 if (code == MINUS_EXPR)
1592 p1 = double_int_neg (p1);
1593 *mul = double_int_sext (double_int_add (p0, p1), precision);
1597 if (TREE_CODE (bot) != INTEGER_CST)
1600 p0 = double_int_sext (tree_to_double_int (top), precision);
1601 p1 = double_int_sext (tree_to_double_int (bot), precision);
1602 if (double_int_zero_p (p1))
1604 *mul = double_int_sext (double_int_sdivmod (p0, p1, FLOOR_DIV_EXPR, &res),
1606 return double_int_zero_p (res);
1613 /* Returns true if memory reference REF with step STEP may be unaligned. */
1616 may_be_unaligned_p (tree ref, tree step)
1620 HOST_WIDE_INT bitsize;
1621 HOST_WIDE_INT bitpos;
1623 enum machine_mode mode;
1624 int unsignedp, volatilep;
1625 unsigned base_align;
1627 /* TARGET_MEM_REFs are translated directly to valid MEMs on the target,
1628 thus they are not misaligned. */
1629 if (TREE_CODE (ref) == TARGET_MEM_REF)
1632 /* The test below is basically copy of what expr.c:normal_inner_ref
1633 does to check whether the object must be loaded by parts when
1634 STRICT_ALIGNMENT is true. */
1635 base = get_inner_reference (ref, &bitsize, &bitpos, &toffset, &mode,
1636 &unsignedp, &volatilep, true);
1637 base_type = TREE_TYPE (base);
1638 base_align = get_object_alignment (base);
1639 base_align = MAX (base_align, TYPE_ALIGN (base_type));
1641 if (mode != BLKmode)
1643 unsigned mode_align = GET_MODE_ALIGNMENT (mode);
1645 if (base_align < mode_align
1646 || (bitpos % mode_align) != 0
1647 || (bitpos % BITS_PER_UNIT) != 0)
1651 && (highest_pow2_factor (toffset) * BITS_PER_UNIT) < mode_align)
1654 if ((highest_pow2_factor (step) * BITS_PER_UNIT) < mode_align)
1661 /* Return true if EXPR may be non-addressable. */
1664 may_be_nonaddressable_p (tree expr)
1666 switch (TREE_CODE (expr))
1668 case TARGET_MEM_REF:
1669 /* TARGET_MEM_REFs are translated directly to valid MEMs on the
1670 target, thus they are always addressable. */
1674 return DECL_NONADDRESSABLE_P (TREE_OPERAND (expr, 1))
1675 || may_be_nonaddressable_p (TREE_OPERAND (expr, 0));
1677 case VIEW_CONVERT_EXPR:
1678 /* This kind of view-conversions may wrap non-addressable objects
1679 and make them look addressable. After some processing the
1680 non-addressability may be uncovered again, causing ADDR_EXPRs
1681 of inappropriate objects to be built. */
1682 if (is_gimple_reg (TREE_OPERAND (expr, 0))
1683 || !is_gimple_addressable (TREE_OPERAND (expr, 0)))
1686 /* ... fall through ... */
1689 case ARRAY_RANGE_REF:
1690 return may_be_nonaddressable_p (TREE_OPERAND (expr, 0));
1702 /* Finds addresses in *OP_P inside STMT. */
1705 find_interesting_uses_address (struct ivopts_data *data, gimple stmt, tree *op_p)
1707 tree base = *op_p, step = size_zero_node;
1709 struct ifs_ivopts_data ifs_ivopts_data;
1711 /* Do not play with volatile memory references. A bit too conservative,
1712 perhaps, but safe. */
1713 if (gimple_has_volatile_ops (stmt))
1716 /* Ignore bitfields for now. Not really something terribly complicated
1718 if (TREE_CODE (base) == BIT_FIELD_REF)
1721 base = unshare_expr (base);
1723 if (TREE_CODE (base) == TARGET_MEM_REF)
1725 tree type = build_pointer_type (TREE_TYPE (base));
1729 && TREE_CODE (TMR_BASE (base)) == SSA_NAME)
1731 civ = get_iv (data, TMR_BASE (base));
1735 TMR_BASE (base) = civ->base;
1738 if (TMR_INDEX2 (base)
1739 && TREE_CODE (TMR_INDEX2 (base)) == SSA_NAME)
1741 civ = get_iv (data, TMR_INDEX2 (base));
1745 TMR_INDEX2 (base) = civ->base;
1748 if (TMR_INDEX (base)
1749 && TREE_CODE (TMR_INDEX (base)) == SSA_NAME)
1751 civ = get_iv (data, TMR_INDEX (base));
1755 TMR_INDEX (base) = civ->base;
1760 if (TMR_STEP (base))
1761 astep = fold_build2 (MULT_EXPR, type, TMR_STEP (base), astep);
1763 step = fold_build2 (PLUS_EXPR, type, step, astep);
1767 if (integer_zerop (step))
1769 base = tree_mem_ref_addr (type, base);
1773 ifs_ivopts_data.ivopts_data = data;
1774 ifs_ivopts_data.stmt = stmt;
1775 ifs_ivopts_data.step = size_zero_node;
1776 if (!for_each_index (&base, idx_find_step, &ifs_ivopts_data)
1777 || integer_zerop (ifs_ivopts_data.step))
1779 step = ifs_ivopts_data.step;
1781 /* Check that the base expression is addressable. This needs
1782 to be done after substituting bases of IVs into it. */
1783 if (may_be_nonaddressable_p (base))
1786 /* Moreover, on strict alignment platforms, check that it is
1787 sufficiently aligned. */
1788 if (STRICT_ALIGNMENT && may_be_unaligned_p (base, step))
1791 base = build_fold_addr_expr (base);
1793 /* Substituting bases of IVs into the base expression might
1794 have caused folding opportunities. */
1795 if (TREE_CODE (base) == ADDR_EXPR)
1797 tree *ref = &TREE_OPERAND (base, 0);
1798 while (handled_component_p (*ref))
1799 ref = &TREE_OPERAND (*ref, 0);
1800 if (TREE_CODE (*ref) == MEM_REF)
1802 tree tem = fold_binary (MEM_REF, TREE_TYPE (*ref),
1803 TREE_OPERAND (*ref, 0),
1804 TREE_OPERAND (*ref, 1));
1811 civ = alloc_iv (base, step);
1812 record_use (data, op_p, civ, stmt, USE_ADDRESS);
1816 for_each_index (op_p, idx_record_use, data);
1819 /* Finds and records invariants used in STMT. */
1822 find_invariants_stmt (struct ivopts_data *data, gimple stmt)
1825 use_operand_p use_p;
1828 FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
1830 op = USE_FROM_PTR (use_p);
1831 record_invariant (data, op, false);
1835 /* Finds interesting uses of induction variables in the statement STMT. */
1838 find_interesting_uses_stmt (struct ivopts_data *data, gimple stmt)
1841 tree op, *lhs, *rhs;
1843 use_operand_p use_p;
1844 enum tree_code code;
1846 find_invariants_stmt (data, stmt);
1848 if (gimple_code (stmt) == GIMPLE_COND)
1850 find_interesting_uses_cond (data, stmt);
1854 if (is_gimple_assign (stmt))
1856 lhs = gimple_assign_lhs_ptr (stmt);
1857 rhs = gimple_assign_rhs1_ptr (stmt);
1859 if (TREE_CODE (*lhs) == SSA_NAME)
1861 /* If the statement defines an induction variable, the uses are not
1862 interesting by themselves. */
1864 iv = get_iv (data, *lhs);
1866 if (iv && !integer_zerop (iv->step))
1870 code = gimple_assign_rhs_code (stmt);
1871 if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS
1872 && (REFERENCE_CLASS_P (*rhs)
1873 || is_gimple_val (*rhs)))
1875 if (REFERENCE_CLASS_P (*rhs))
1876 find_interesting_uses_address (data, stmt, rhs);
1878 find_interesting_uses_op (data, *rhs);
1880 if (REFERENCE_CLASS_P (*lhs))
1881 find_interesting_uses_address (data, stmt, lhs);
1884 else if (TREE_CODE_CLASS (code) == tcc_comparison)
1886 find_interesting_uses_cond (data, stmt);
1890 /* TODO -- we should also handle address uses of type
1892 memory = call (whatever);
1899 if (gimple_code (stmt) == GIMPLE_PHI
1900 && gimple_bb (stmt) == data->current_loop->header)
1902 iv = get_iv (data, PHI_RESULT (stmt));
1904 if (iv && !integer_zerop (iv->step))
1908 FOR_EACH_PHI_OR_STMT_USE (use_p, stmt, iter, SSA_OP_USE)
1910 op = USE_FROM_PTR (use_p);
1912 if (TREE_CODE (op) != SSA_NAME)
1915 iv = get_iv (data, op);
1919 find_interesting_uses_op (data, op);
1923 /* Finds interesting uses of induction variables outside of loops
1924 on loop exit edge EXIT. */
1927 find_interesting_uses_outside (struct ivopts_data *data, edge exit)
1930 gimple_stmt_iterator psi;
1933 for (psi = gsi_start_phis (exit->dest); !gsi_end_p (psi); gsi_next (&psi))
1935 phi = gsi_stmt (psi);
1936 def = PHI_ARG_DEF_FROM_EDGE (phi, exit);
1937 if (is_gimple_reg (def))
1938 find_interesting_uses_op (data, def);
1942 /* Finds uses of the induction variables that are interesting. */
1945 find_interesting_uses (struct ivopts_data *data)
1948 gimple_stmt_iterator bsi;
1949 basic_block *body = get_loop_body (data->current_loop);
1951 struct version_info *info;
1954 if (dump_file && (dump_flags & TDF_DETAILS))
1955 fprintf (dump_file, "Uses:\n\n");
1957 for (i = 0; i < data->current_loop->num_nodes; i++)
1962 FOR_EACH_EDGE (e, ei, bb->succs)
1963 if (e->dest != EXIT_BLOCK_PTR
1964 && !flow_bb_inside_loop_p (data->current_loop, e->dest))
1965 find_interesting_uses_outside (data, e);
1967 for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
1968 find_interesting_uses_stmt (data, gsi_stmt (bsi));
1969 for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
1970 if (!is_gimple_debug (gsi_stmt (bsi)))
1971 find_interesting_uses_stmt (data, gsi_stmt (bsi));
1974 if (dump_file && (dump_flags & TDF_DETAILS))
1978 fprintf (dump_file, "\n");
1980 EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
1982 info = ver_info (data, i);
1985 fprintf (dump_file, " ");
1986 print_generic_expr (dump_file, info->name, TDF_SLIM);
1987 fprintf (dump_file, " is invariant (%d)%s\n",
1988 info->inv_id, info->has_nonlin_use ? "" : ", eliminable");
1992 fprintf (dump_file, "\n");
1998 /* Strips constant offsets from EXPR and stores them to OFFSET. If INSIDE_ADDR
1999 is true, assume we are inside an address. If TOP_COMPREF is true, assume
2000 we are at the top-level of the processed address. */
2003 strip_offset_1 (tree expr, bool inside_addr, bool top_compref,
2004 unsigned HOST_WIDE_INT *offset)
2006 tree op0 = NULL_TREE, op1 = NULL_TREE, tmp, step;
2007 enum tree_code code;
2008 tree type, orig_type = TREE_TYPE (expr);
2009 unsigned HOST_WIDE_INT off0, off1, st;
2010 tree orig_expr = expr;
2014 type = TREE_TYPE (expr);
2015 code = TREE_CODE (expr);
2021 if (!cst_and_fits_in_hwi (expr)
2022 || integer_zerop (expr))
2025 *offset = int_cst_value (expr);
2026 return build_int_cst (orig_type, 0);
2028 case POINTER_PLUS_EXPR:
2031 op0 = TREE_OPERAND (expr, 0);
2032 op1 = TREE_OPERAND (expr, 1);
2034 op0 = strip_offset_1 (op0, false, false, &off0);
2035 op1 = strip_offset_1 (op1, false, false, &off1);
2037 *offset = (code == MINUS_EXPR ? off0 - off1 : off0 + off1);
2038 if (op0 == TREE_OPERAND (expr, 0)
2039 && op1 == TREE_OPERAND (expr, 1))
2042 if (integer_zerop (op1))
2044 else if (integer_zerop (op0))
2046 if (code == MINUS_EXPR)
2047 expr = fold_build1 (NEGATE_EXPR, type, op1);
2052 expr = fold_build2 (code, type, op0, op1);
2054 return fold_convert (orig_type, expr);
2057 op1 = TREE_OPERAND (expr, 1);
2058 if (!cst_and_fits_in_hwi (op1))
2061 op0 = TREE_OPERAND (expr, 0);
2062 op0 = strip_offset_1 (op0, false, false, &off0);
2063 if (op0 == TREE_OPERAND (expr, 0))
2066 *offset = off0 * int_cst_value (op1);
2067 if (integer_zerop (op0))
2070 expr = fold_build2 (MULT_EXPR, type, op0, op1);
2072 return fold_convert (orig_type, expr);
2075 case ARRAY_RANGE_REF:
2079 step = array_ref_element_size (expr);
2080 if (!cst_and_fits_in_hwi (step))
2083 st = int_cst_value (step);
2084 op1 = TREE_OPERAND (expr, 1);
2085 op1 = strip_offset_1 (op1, false, false, &off1);
2086 *offset = off1 * st;
2089 && integer_zerop (op1))
2091 /* Strip the component reference completely. */
2092 op0 = TREE_OPERAND (expr, 0);
2093 op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
2103 tmp = component_ref_field_offset (expr);
2105 && cst_and_fits_in_hwi (tmp))
2107 /* Strip the component reference completely. */
2108 op0 = TREE_OPERAND (expr, 0);
2109 op0 = strip_offset_1 (op0, inside_addr, top_compref, &off0);
2110 *offset = off0 + int_cst_value (tmp);
2116 op0 = TREE_OPERAND (expr, 0);
2117 op0 = strip_offset_1 (op0, true, true, &off0);
2120 if (op0 == TREE_OPERAND (expr, 0))
2123 expr = build_fold_addr_expr (op0);
2124 return fold_convert (orig_type, expr);
2127 /* ??? Offset operand? */
2128 inside_addr = false;
2135 /* Default handling of expressions for that we want to recurse into
2136 the first operand. */
2137 op0 = TREE_OPERAND (expr, 0);
2138 op0 = strip_offset_1 (op0, inside_addr, false, &off0);
2141 if (op0 == TREE_OPERAND (expr, 0)
2142 && (!op1 || op1 == TREE_OPERAND (expr, 1)))
2145 expr = copy_node (expr);
2146 TREE_OPERAND (expr, 0) = op0;
2148 TREE_OPERAND (expr, 1) = op1;
2150 /* Inside address, we might strip the top level component references,
2151 thus changing type of the expression. Handling of ADDR_EXPR
2153 expr = fold_convert (orig_type, expr);
2158 /* Strips constant offsets from EXPR and stores them to OFFSET. */
2161 strip_offset (tree expr, unsigned HOST_WIDE_INT *offset)
2163 return strip_offset_1 (expr, false, false, offset);
2166 /* Returns variant of TYPE that can be used as base for different uses.
2167 We return unsigned type with the same precision, which avoids problems
2171 generic_type_for (tree type)
2173 if (POINTER_TYPE_P (type))
2174 return unsigned_type_for (type);
2176 if (TYPE_UNSIGNED (type))
2179 return unsigned_type_for (type);
2182 /* Records invariants in *EXPR_P. Callback for walk_tree. DATA contains
2183 the bitmap to that we should store it. */
2185 static struct ivopts_data *fd_ivopts_data;
2187 find_depends (tree *expr_p, int *ws ATTRIBUTE_UNUSED, void *data)
2189 bitmap *depends_on = (bitmap *) data;
2190 struct version_info *info;
2192 if (TREE_CODE (*expr_p) != SSA_NAME)
2194 info = name_info (fd_ivopts_data, *expr_p);
2196 if (!info->inv_id || info->has_nonlin_use)
2200 *depends_on = BITMAP_ALLOC (NULL);
2201 bitmap_set_bit (*depends_on, info->inv_id);
2206 /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and
2207 position to POS. If USE is not NULL, the candidate is set as related to
2208 it. If both BASE and STEP are NULL, we add a pseudocandidate for the
2209 replacement of the final value of the iv by a direct computation. */
2211 static struct iv_cand *
2212 add_candidate_1 (struct ivopts_data *data,
2213 tree base, tree step, bool important, enum iv_position pos,
2214 struct iv_use *use, gimple incremented_at)
2217 struct iv_cand *cand = NULL;
2218 tree type, orig_type;
2222 orig_type = TREE_TYPE (base);
2223 type = generic_type_for (orig_type);
2224 if (type != orig_type)
2226 base = fold_convert (type, base);
2227 step = fold_convert (type, step);
2231 for (i = 0; i < n_iv_cands (data); i++)
2233 cand = iv_cand (data, i);
2235 if (cand->pos != pos)
2238 if (cand->incremented_at != incremented_at
2239 || ((pos == IP_AFTER_USE || pos == IP_BEFORE_USE)
2240 && cand->ainc_use != use))
2254 if (operand_equal_p (base, cand->iv->base, 0)
2255 && operand_equal_p (step, cand->iv->step, 0)
2256 && (TYPE_PRECISION (TREE_TYPE (base))
2257 == TYPE_PRECISION (TREE_TYPE (cand->iv->base))))
2261 if (i == n_iv_cands (data))
2263 cand = XCNEW (struct iv_cand);
2269 cand->iv = alloc_iv (base, step);
2272 if (pos != IP_ORIGINAL && cand->iv)
2274 cand->var_before = create_tmp_var_raw (TREE_TYPE (base), "ivtmp");
2275 cand->var_after = cand->var_before;
2277 cand->important = important;
2278 cand->incremented_at = incremented_at;
2279 VEC_safe_push (iv_cand_p, heap, data->iv_candidates, cand);
2282 && TREE_CODE (step) != INTEGER_CST)
2284 fd_ivopts_data = data;
2285 walk_tree (&step, find_depends, &cand->depends_on, NULL);
2288 if (pos == IP_AFTER_USE || pos == IP_BEFORE_USE)
2289 cand->ainc_use = use;
2291 cand->ainc_use = NULL;
2293 if (dump_file && (dump_flags & TDF_DETAILS))
2294 dump_cand (dump_file, cand);
2297 if (important && !cand->important)
2299 cand->important = true;
2300 if (dump_file && (dump_flags & TDF_DETAILS))
2301 fprintf (dump_file, "Candidate %d is important\n", cand->id);
2306 bitmap_set_bit (use->related_cands, i);
2307 if (dump_file && (dump_flags & TDF_DETAILS))
2308 fprintf (dump_file, "Candidate %d is related to use %d\n",
2315 /* Returns true if incrementing the induction variable at the end of the LOOP
2318 The purpose is to avoid splitting latch edge with a biv increment, thus
2319 creating a jump, possibly confusing other optimization passes and leaving
2320 less freedom to scheduler. So we allow IP_END_POS only if IP_NORMAL_POS
2321 is not available (so we do not have a better alternative), or if the latch
2322 edge is already nonempty. */
2325 allow_ip_end_pos_p (struct loop *loop)
2327 if (!ip_normal_pos (loop))
2330 if (!empty_block_p (ip_end_pos (loop)))
2336 /* If possible, adds autoincrement candidates BASE + STEP * i based on use USE.
2337 Important field is set to IMPORTANT. */
2340 add_autoinc_candidates (struct ivopts_data *data, tree base, tree step,
2341 bool important, struct iv_use *use)
2343 basic_block use_bb = gimple_bb (use->stmt);
2344 enum machine_mode mem_mode;
2345 unsigned HOST_WIDE_INT cstepi;
2347 /* If we insert the increment in any position other than the standard
2348 ones, we must ensure that it is incremented once per iteration.
2349 It must not be in an inner nested loop, or one side of an if
2351 if (use_bb->loop_father != data->current_loop
2352 || !dominated_by_p (CDI_DOMINATORS, data->current_loop->latch, use_bb)
2353 || stmt_could_throw_p (use->stmt)
2354 || !cst_and_fits_in_hwi (step))
2357 cstepi = int_cst_value (step);
2359 mem_mode = TYPE_MODE (TREE_TYPE (*use->op_p));
2360 if ((HAVE_PRE_INCREMENT && GET_MODE_SIZE (mem_mode) == cstepi)
2361 || (HAVE_PRE_DECREMENT && GET_MODE_SIZE (mem_mode) == -cstepi))
2363 enum tree_code code = MINUS_EXPR;
2365 tree new_step = step;
2367 if (POINTER_TYPE_P (TREE_TYPE (base)))
2369 new_step = fold_build1 (NEGATE_EXPR, TREE_TYPE (step), step);
2370 code = POINTER_PLUS_EXPR;
2373 new_step = fold_convert (TREE_TYPE (base), new_step);
2374 new_base = fold_build2 (code, TREE_TYPE (base), base, new_step);
2375 add_candidate_1 (data, new_base, step, important, IP_BEFORE_USE, use,
2378 if ((HAVE_POST_INCREMENT && GET_MODE_SIZE (mem_mode) == cstepi)
2379 || (HAVE_POST_DECREMENT && GET_MODE_SIZE (mem_mode) == -cstepi))
2381 add_candidate_1 (data, base, step, important, IP_AFTER_USE, use,
2386 /* Adds a candidate BASE + STEP * i. Important field is set to IMPORTANT and
2387 position to POS. If USE is not NULL, the candidate is set as related to
2388 it. The candidate computation is scheduled on all available positions. */
2391 add_candidate (struct ivopts_data *data,
2392 tree base, tree step, bool important, struct iv_use *use)
2394 if (ip_normal_pos (data->current_loop))
2395 add_candidate_1 (data, base, step, important, IP_NORMAL, use, NULL);
2396 if (ip_end_pos (data->current_loop)
2397 && allow_ip_end_pos_p (data->current_loop))
2398 add_candidate_1 (data, base, step, important, IP_END, use, NULL);
2400 if (use != NULL && use->type == USE_ADDRESS)
2401 add_autoinc_candidates (data, base, step, important, use);
2404 /* Add a standard "0 + 1 * iteration" iv candidate for a
2405 type with SIZE bits. */
2408 add_standard_iv_candidates_for_size (struct ivopts_data *data,
2411 tree type = lang_hooks.types.type_for_size (size, true);
2412 add_candidate (data, build_int_cst (type, 0), build_int_cst (type, 1),
2416 /* Adds standard iv candidates. */
2419 add_standard_iv_candidates (struct ivopts_data *data)
2421 add_standard_iv_candidates_for_size (data, INT_TYPE_SIZE);
2423 /* The same for a double-integer type if it is still fast enough. */
2424 if (BITS_PER_WORD >= INT_TYPE_SIZE * 2)
2425 add_standard_iv_candidates_for_size (data, INT_TYPE_SIZE * 2);
2429 /* Adds candidates bases on the old induction variable IV. */
2432 add_old_iv_candidates (struct ivopts_data *data, struct iv *iv)
2436 struct iv_cand *cand;
2438 add_candidate (data, iv->base, iv->step, true, NULL);
2440 /* The same, but with initial value zero. */
2441 if (POINTER_TYPE_P (TREE_TYPE (iv->base)))
2442 add_candidate (data, size_int (0), iv->step, true, NULL);
2444 add_candidate (data, build_int_cst (TREE_TYPE (iv->base), 0),
2445 iv->step, true, NULL);
2447 phi = SSA_NAME_DEF_STMT (iv->ssa_name);
2448 if (gimple_code (phi) == GIMPLE_PHI)
2450 /* Additionally record the possibility of leaving the original iv
2452 def = PHI_ARG_DEF_FROM_EDGE (phi, loop_latch_edge (data->current_loop));
2453 cand = add_candidate_1 (data,
2454 iv->base, iv->step, true, IP_ORIGINAL, NULL,
2455 SSA_NAME_DEF_STMT (def));
2456 cand->var_before = iv->ssa_name;
2457 cand->var_after = def;
2461 /* Adds candidates based on the old induction variables. */
2464 add_old_ivs_candidates (struct ivopts_data *data)
2470 EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
2472 iv = ver_info (data, i)->iv;
2473 if (iv && iv->biv_p && !integer_zerop (iv->step))
2474 add_old_iv_candidates (data, iv);
2478 /* Adds candidates based on the value of the induction variable IV and USE. */
2481 add_iv_value_candidates (struct ivopts_data *data,
2482 struct iv *iv, struct iv_use *use)
2484 unsigned HOST_WIDE_INT offset;
2488 add_candidate (data, iv->base, iv->step, false, use);
2490 /* The same, but with initial value zero. Make such variable important,
2491 since it is generic enough so that possibly many uses may be based
2493 basetype = TREE_TYPE (iv->base);
2494 if (POINTER_TYPE_P (basetype))
2495 basetype = sizetype;
2496 add_candidate (data, build_int_cst (basetype, 0),
2497 iv->step, true, use);
2499 /* Third, try removing the constant offset. Make sure to even
2500 add a candidate for &a[0] vs. (T *)&a. */
2501 base = strip_offset (iv->base, &offset);
2503 || base != iv->base)
2504 add_candidate (data, base, iv->step, false, use);
2507 /* Adds candidates based on the uses. */
2510 add_derived_ivs_candidates (struct ivopts_data *data)
2514 for (i = 0; i < n_iv_uses (data); i++)
2516 struct iv_use *use = iv_use (data, i);
2523 case USE_NONLINEAR_EXPR:
2526 /* Just add the ivs based on the value of the iv used here. */
2527 add_iv_value_candidates (data, use->iv, use);
2536 /* Record important candidates and add them to related_cands bitmaps
2540 record_important_candidates (struct ivopts_data *data)
2545 for (i = 0; i < n_iv_cands (data); i++)
2547 struct iv_cand *cand = iv_cand (data, i);
2549 if (cand->important)
2550 bitmap_set_bit (data->important_candidates, i);
2553 data->consider_all_candidates = (n_iv_cands (data)
2554 <= CONSIDER_ALL_CANDIDATES_BOUND);
2556 if (data->consider_all_candidates)
2558 /* We will not need "related_cands" bitmaps in this case,
2559 so release them to decrease peak memory consumption. */
2560 for (i = 0; i < n_iv_uses (data); i++)
2562 use = iv_use (data, i);
2563 BITMAP_FREE (use->related_cands);
2568 /* Add important candidates to the related_cands bitmaps. */
2569 for (i = 0; i < n_iv_uses (data); i++)
2570 bitmap_ior_into (iv_use (data, i)->related_cands,
2571 data->important_candidates);
2575 /* Allocates the data structure mapping the (use, candidate) pairs to costs.
2576 If consider_all_candidates is true, we use a two-dimensional array, otherwise
2577 we allocate a simple list to every use. */
2580 alloc_use_cost_map (struct ivopts_data *data)
2582 unsigned i, size, s, j;
2584 for (i = 0; i < n_iv_uses (data); i++)
2586 struct iv_use *use = iv_use (data, i);
2589 if (data->consider_all_candidates)
2590 size = n_iv_cands (data);
2594 EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi)
2599 /* Round up to the power of two, so that moduling by it is fast. */
2600 for (size = 1; size < s; size <<= 1)
2604 use->n_map_members = size;
2605 use->cost_map = XCNEWVEC (struct cost_pair, size);
2609 /* Returns description of computation cost of expression whose runtime
2610 cost is RUNTIME and complexity corresponds to COMPLEXITY. */
2613 new_cost (unsigned runtime, unsigned complexity)
2617 cost.cost = runtime;
2618 cost.complexity = complexity;
2623 /* Adds costs COST1 and COST2. */
2626 add_costs (comp_cost cost1, comp_cost cost2)
2628 cost1.cost += cost2.cost;
2629 cost1.complexity += cost2.complexity;
2633 /* Subtracts costs COST1 and COST2. */
2636 sub_costs (comp_cost cost1, comp_cost cost2)
2638 cost1.cost -= cost2.cost;
2639 cost1.complexity -= cost2.complexity;
2644 /* Returns a negative number if COST1 < COST2, a positive number if
2645 COST1 > COST2, and 0 if COST1 = COST2. */
2648 compare_costs (comp_cost cost1, comp_cost cost2)
2650 if (cost1.cost == cost2.cost)
2651 return cost1.complexity - cost2.complexity;
2653 return cost1.cost - cost2.cost;
2656 /* Returns true if COST is infinite. */
2659 infinite_cost_p (comp_cost cost)
2661 return cost.cost == INFTY;
2664 /* Sets cost of (USE, CANDIDATE) pair to COST and record that it depends
2665 on invariants DEPENDS_ON and that the value used in expressing it
2669 set_use_iv_cost (struct ivopts_data *data,
2670 struct iv_use *use, struct iv_cand *cand,
2671 comp_cost cost, bitmap depends_on, tree value,
2676 if (infinite_cost_p (cost))
2678 BITMAP_FREE (depends_on);
2682 if (data->consider_all_candidates)
2684 use->cost_map[cand->id].cand = cand;
2685 use->cost_map[cand->id].cost = cost;
2686 use->cost_map[cand->id].depends_on = depends_on;
2687 use->cost_map[cand->id].value = value;
2688 use->cost_map[cand->id].inv_expr_id = inv_expr_id;
2692 /* n_map_members is a power of two, so this computes modulo. */
2693 s = cand->id & (use->n_map_members - 1);
2694 for (i = s; i < use->n_map_members; i++)
2695 if (!use->cost_map[i].cand)
2697 for (i = 0; i < s; i++)
2698 if (!use->cost_map[i].cand)
2704 use->cost_map[i].cand = cand;
2705 use->cost_map[i].cost = cost;
2706 use->cost_map[i].depends_on = depends_on;
2707 use->cost_map[i].value = value;
2708 use->cost_map[i].inv_expr_id = inv_expr_id;
2711 /* Gets cost of (USE, CANDIDATE) pair. */
2713 static struct cost_pair *
2714 get_use_iv_cost (struct ivopts_data *data, struct iv_use *use,
2715 struct iv_cand *cand)
2718 struct cost_pair *ret;
2723 if (data->consider_all_candidates)
2725 ret = use->cost_map + cand->id;
2732 /* n_map_members is a power of two, so this computes modulo. */
2733 s = cand->id & (use->n_map_members - 1);
2734 for (i = s; i < use->n_map_members; i++)
2735 if (use->cost_map[i].cand == cand)
2736 return use->cost_map + i;
2738 for (i = 0; i < s; i++)
2739 if (use->cost_map[i].cand == cand)
2740 return use->cost_map + i;
2745 /* Returns estimate on cost of computing SEQ. */
2748 seq_cost (rtx seq, bool speed)
2753 for (; seq; seq = NEXT_INSN (seq))
2755 set = single_set (seq);
2757 cost += rtx_cost (SET_SRC (set), SET, speed);
2765 /* Produce DECL_RTL for object obj so it looks like it is stored in memory. */
2767 produce_memory_decl_rtl (tree obj, int *regno)
2769 addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (obj));
2770 enum machine_mode address_mode = targetm.addr_space.address_mode (as);
2774 if (TREE_STATIC (obj) || DECL_EXTERNAL (obj))
2776 const char *name = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (obj));
2777 x = gen_rtx_SYMBOL_REF (address_mode, name);
2778 SET_SYMBOL_REF_DECL (x, obj);
2779 x = gen_rtx_MEM (DECL_MODE (obj), x);
2780 set_mem_addr_space (x, as);
2781 targetm.encode_section_info (obj, x, true);
2785 x = gen_raw_REG (address_mode, (*regno)++);
2786 x = gen_rtx_MEM (DECL_MODE (obj), x);
2787 set_mem_addr_space (x, as);
2793 /* Prepares decl_rtl for variables referred in *EXPR_P. Callback for
2794 walk_tree. DATA contains the actual fake register number. */
2797 prepare_decl_rtl (tree *expr_p, int *ws, void *data)
2799 tree obj = NULL_TREE;
2801 int *regno = (int *) data;
2803 switch (TREE_CODE (*expr_p))
2806 for (expr_p = &TREE_OPERAND (*expr_p, 0);
2807 handled_component_p (*expr_p);
2808 expr_p = &TREE_OPERAND (*expr_p, 0))
2811 if (DECL_P (obj) && !DECL_RTL_SET_P (obj))
2812 x = produce_memory_decl_rtl (obj, regno);
2817 obj = SSA_NAME_VAR (*expr_p);
2818 if (!DECL_RTL_SET_P (obj))
2819 x = gen_raw_REG (DECL_MODE (obj), (*regno)++);
2828 if (DECL_RTL_SET_P (obj))
2831 if (DECL_MODE (obj) == BLKmode)
2832 x = produce_memory_decl_rtl (obj, regno);
2834 x = gen_raw_REG (DECL_MODE (obj), (*regno)++);
2844 VEC_safe_push (tree, heap, decl_rtl_to_reset, obj);
2845 SET_DECL_RTL (obj, x);
2851 /* Determines cost of the computation of EXPR. */
2854 computation_cost (tree expr, bool speed)
2857 tree type = TREE_TYPE (expr);
2859 /* Avoid using hard regs in ways which may be unsupported. */
2860 int regno = LAST_VIRTUAL_REGISTER + 1;
2861 struct cgraph_node *node = cgraph_get_node (current_function_decl);
2862 enum node_frequency real_frequency = node->frequency;
2864 node->frequency = NODE_FREQUENCY_NORMAL;
2865 crtl->maybe_hot_insn_p = speed;
2866 walk_tree (&expr, prepare_decl_rtl, ®no, NULL);
2868 rslt = expand_expr (expr, NULL_RTX, TYPE_MODE (type), EXPAND_NORMAL);
2871 default_rtl_profile ();
2872 node->frequency = real_frequency;
2874 cost = seq_cost (seq, speed);
2876 cost += address_cost (XEXP (rslt, 0), TYPE_MODE (type),
2877 TYPE_ADDR_SPACE (type), speed);
2878 else if (!REG_P (rslt))
2879 cost += rtx_cost (rslt, SET, speed);
2884 /* Returns variable containing the value of candidate CAND at statement AT. */
2887 var_at_stmt (struct loop *loop, struct iv_cand *cand, gimple stmt)
2889 if (stmt_after_increment (loop, cand, stmt))
2890 return cand->var_after;
2892 return cand->var_before;
2895 /* Return the most significant (sign) bit of T. Similar to tree_int_cst_msb,
2896 but the bit is determined from TYPE_PRECISION, not MODE_BITSIZE. */
2899 tree_int_cst_sign_bit (const_tree t)
2901 unsigned bitno = TYPE_PRECISION (TREE_TYPE (t)) - 1;
2902 unsigned HOST_WIDE_INT w;
2904 if (bitno < HOST_BITS_PER_WIDE_INT)
2905 w = TREE_INT_CST_LOW (t);
2908 w = TREE_INT_CST_HIGH (t);
2909 bitno -= HOST_BITS_PER_WIDE_INT;
2912 return (w >> bitno) & 1;
2915 /* If A is (TYPE) BA and B is (TYPE) BB, and the types of BA and BB have the
2916 same precision that is at least as wide as the precision of TYPE, stores
2917 BA to A and BB to B, and returns the type of BA. Otherwise, returns the
2921 determine_common_wider_type (tree *a, tree *b)
2923 tree wider_type = NULL;
2925 tree atype = TREE_TYPE (*a);
2927 if (CONVERT_EXPR_P (*a))
2929 suba = TREE_OPERAND (*a, 0);
2930 wider_type = TREE_TYPE (suba);
2931 if (TYPE_PRECISION (wider_type) < TYPE_PRECISION (atype))
2937 if (CONVERT_EXPR_P (*b))
2939 subb = TREE_OPERAND (*b, 0);
2940 if (TYPE_PRECISION (wider_type) != TYPE_PRECISION (TREE_TYPE (subb)))
2951 /* Determines the expression by that USE is expressed from induction variable
2952 CAND at statement AT in LOOP. The expression is stored in a decomposed
2953 form into AFF. Returns false if USE cannot be expressed using CAND. */
2956 get_computation_aff (struct loop *loop,
2957 struct iv_use *use, struct iv_cand *cand, gimple at,
2958 struct affine_tree_combination *aff)
2960 tree ubase = use->iv->base;
2961 tree ustep = use->iv->step;
2962 tree cbase = cand->iv->base;
2963 tree cstep = cand->iv->step, cstep_common;
2964 tree utype = TREE_TYPE (ubase), ctype = TREE_TYPE (cbase);
2965 tree common_type, var;
2967 aff_tree cbase_aff, var_aff;
2970 if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype))
2972 /* We do not have a precision to express the values of use. */
2976 var = var_at_stmt (loop, cand, at);
2977 uutype = unsigned_type_for (utype);
2979 /* If the conversion is not noop, perform it. */
2980 if (TYPE_PRECISION (utype) < TYPE_PRECISION (ctype))
2982 cstep = fold_convert (uutype, cstep);
2983 cbase = fold_convert (uutype, cbase);
2984 var = fold_convert (uutype, var);
2987 if (!constant_multiple_of (ustep, cstep, &rat))
2990 /* In case both UBASE and CBASE are shortened to UUTYPE from some common
2991 type, we achieve better folding by computing their difference in this
2992 wider type, and cast the result to UUTYPE. We do not need to worry about
2993 overflows, as all the arithmetics will in the end be performed in UUTYPE
2995 common_type = determine_common_wider_type (&ubase, &cbase);
2997 /* use = ubase - ratio * cbase + ratio * var. */
2998 tree_to_aff_combination (ubase, common_type, aff);
2999 tree_to_aff_combination (cbase, common_type, &cbase_aff);
3000 tree_to_aff_combination (var, uutype, &var_aff);
3002 /* We need to shift the value if we are after the increment. */
3003 if (stmt_after_increment (loop, cand, at))
3007 if (common_type != uutype)
3008 cstep_common = fold_convert (common_type, cstep);
3010 cstep_common = cstep;
3012 tree_to_aff_combination (cstep_common, common_type, &cstep_aff);
3013 aff_combination_add (&cbase_aff, &cstep_aff);
3016 aff_combination_scale (&cbase_aff, double_int_neg (rat));
3017 aff_combination_add (aff, &cbase_aff);
3018 if (common_type != uutype)
3019 aff_combination_convert (aff, uutype);
3021 aff_combination_scale (&var_aff, rat);
3022 aff_combination_add (aff, &var_aff);
3027 /* Determines the expression by that USE is expressed from induction variable
3028 CAND at statement AT in LOOP. The computation is unshared. */
3031 get_computation_at (struct loop *loop,
3032 struct iv_use *use, struct iv_cand *cand, gimple at)
3035 tree type = TREE_TYPE (use->iv->base);
3037 if (!get_computation_aff (loop, use, cand, at, &aff))
3039 unshare_aff_combination (&aff);
3040 return fold_convert (type, aff_combination_to_tree (&aff));
3043 /* Determines the expression by that USE is expressed from induction variable
3044 CAND in LOOP. The computation is unshared. */
3047 get_computation (struct loop *loop, struct iv_use *use, struct iv_cand *cand)
3049 return get_computation_at (loop, use, cand, use->stmt);
3052 /* Adjust the cost COST for being in loop setup rather than loop body.
3053 If we're optimizing for space, the loop setup overhead is constant;
3054 if we're optimizing for speed, amortize it over the per-iteration cost. */
3056 adjust_setup_cost (struct ivopts_data *data, unsigned cost)
3060 else if (optimize_loop_for_speed_p (data->current_loop))
3061 return cost / avg_loop_niter (data->current_loop);
3066 /* Returns cost of addition in MODE. */
3069 add_cost (enum machine_mode mode, bool speed)
3071 static unsigned costs[NUM_MACHINE_MODES];
3079 force_operand (gen_rtx_fmt_ee (PLUS, mode,
3080 gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 1),
3081 gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 2)),
3086 cost = seq_cost (seq, speed);
3092 if (dump_file && (dump_flags & TDF_DETAILS))
3093 fprintf (dump_file, "Addition in %s costs %d\n",
3094 GET_MODE_NAME (mode), cost);
3098 /* Entry in a hashtable of already known costs for multiplication. */
3101 HOST_WIDE_INT cst; /* The constant to multiply by. */
3102 enum machine_mode mode; /* In mode. */
3103 unsigned cost; /* The cost. */
3106 /* Counts hash value for the ENTRY. */
3109 mbc_entry_hash (const void *entry)
3111 const struct mbc_entry *e = (const struct mbc_entry *) entry;
3113 return 57 * (hashval_t) e->mode + (hashval_t) (e->cst % 877);
3116 /* Compares the hash table entries ENTRY1 and ENTRY2. */
3119 mbc_entry_eq (const void *entry1, const void *entry2)
3121 const struct mbc_entry *e1 = (const struct mbc_entry *) entry1;
3122 const struct mbc_entry *e2 = (const struct mbc_entry *) entry2;
3124 return (e1->mode == e2->mode
3125 && e1->cst == e2->cst);
3128 /* Returns cost of multiplication by constant CST in MODE. */
3131 multiply_by_cost (HOST_WIDE_INT cst, enum machine_mode mode, bool speed)
3133 static htab_t costs;
3134 struct mbc_entry **cached, act;
3139 costs = htab_create (100, mbc_entry_hash, mbc_entry_eq, free);
3143 cached = (struct mbc_entry **) htab_find_slot (costs, &act, INSERT);
3145 return (*cached)->cost;
3147 *cached = XNEW (struct mbc_entry);
3148 (*cached)->mode = mode;
3149 (*cached)->cst = cst;
3152 expand_mult (mode, gen_raw_REG (mode, LAST_VIRTUAL_REGISTER + 1),
3153 gen_int_mode (cst, mode), NULL_RTX, 0);
3157 cost = seq_cost (seq, speed);
3159 if (dump_file && (dump_flags & TDF_DETAILS))
3160 fprintf (dump_file, "Multiplication by %d in %s costs %d\n",
3161 (int) cst, GET_MODE_NAME (mode), cost);
3163 (*cached)->cost = cost;
3168 /* Returns true if multiplying by RATIO is allowed in an address. Test the
3169 validity for a memory reference accessing memory of mode MODE in
3170 address space AS. */
3172 DEF_VEC_P (sbitmap);
3173 DEF_VEC_ALLOC_P (sbitmap, heap);
3176 multiplier_allowed_in_address_p (HOST_WIDE_INT ratio, enum machine_mode mode,
3179 #define MAX_RATIO 128
3180 unsigned int data_index = (int) as * MAX_MACHINE_MODE + (int) mode;
3181 static VEC (sbitmap, heap) *valid_mult_list;
3184 if (data_index >= VEC_length (sbitmap, valid_mult_list))
3185 VEC_safe_grow_cleared (sbitmap, heap, valid_mult_list, data_index + 1);
3187 valid_mult = VEC_index (sbitmap, valid_mult_list, data_index);
3190 enum machine_mode address_mode = targetm.addr_space.address_mode (as);
3191 rtx reg1 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 1);
3195 valid_mult = sbitmap_alloc (2 * MAX_RATIO + 1);
3196 sbitmap_zero (valid_mult);
3197 addr = gen_rtx_fmt_ee (MULT, address_mode, reg1, NULL_RTX);
3198 for (i = -MAX_RATIO; i <= MAX_RATIO; i++)
3200 XEXP (addr, 1) = gen_int_mode (i, address_mode);
3201 if (memory_address_addr_space_p (mode, addr, as))
3202 SET_BIT (valid_mult, i + MAX_RATIO);
3205 if (dump_file && (dump_flags & TDF_DETAILS))
3207 fprintf (dump_file, " allowed multipliers:");
3208 for (i = -MAX_RATIO; i <= MAX_RATIO; i++)
3209 if (TEST_BIT (valid_mult, i + MAX_RATIO))
3210 fprintf (dump_file, " %d", (int) i);
3211 fprintf (dump_file, "\n");
3212 fprintf (dump_file, "\n");
3215 VEC_replace (sbitmap, valid_mult_list, data_index, valid_mult);
3218 if (ratio > MAX_RATIO || ratio < -MAX_RATIO)
3221 return TEST_BIT (valid_mult, ratio + MAX_RATIO);
3224 /* Returns cost of address in shape symbol + var + OFFSET + RATIO * index.
3225 If SYMBOL_PRESENT is false, symbol is omitted. If VAR_PRESENT is false,
3226 variable is omitted. Compute the cost for a memory reference that accesses
3227 a memory location of mode MEM_MODE in address space AS.
3229 MAY_AUTOINC is set to true if the autoincrement (increasing index by
3230 size of MEM_MODE / RATIO) is available. To make this determination, we
3231 look at the size of the increment to be made, which is given in CSTEP.
3232 CSTEP may be zero if the step is unknown.
3233 STMT_AFTER_INC is true iff the statement we're looking at is after the
3234 increment of the original biv.
3236 TODO -- there must be some better way. This all is quite crude. */
3240 HOST_WIDE_INT min_offset, max_offset;
3241 unsigned costs[2][2][2][2];
3242 } *address_cost_data;
3244 DEF_VEC_P (address_cost_data);
3245 DEF_VEC_ALLOC_P (address_cost_data, heap);
3248 get_address_cost (bool symbol_present, bool var_present,
3249 unsigned HOST_WIDE_INT offset, HOST_WIDE_INT ratio,
3250 HOST_WIDE_INT cstep, enum machine_mode mem_mode,
3251 addr_space_t as, bool speed,
3252 bool stmt_after_inc, bool *may_autoinc)
3254 enum machine_mode address_mode = targetm.addr_space.address_mode (as);
3255 static VEC(address_cost_data, heap) *address_cost_data_list;
3256 unsigned int data_index = (int) as * MAX_MACHINE_MODE + (int) mem_mode;
3257 address_cost_data data;
3258 static bool has_preinc[MAX_MACHINE_MODE], has_postinc[MAX_MACHINE_MODE];
3259 static bool has_predec[MAX_MACHINE_MODE], has_postdec[MAX_MACHINE_MODE];
3260 unsigned cost, acost, complexity;
3261 bool offset_p, ratio_p, autoinc;
3262 HOST_WIDE_INT s_offset, autoinc_offset, msize;
3263 unsigned HOST_WIDE_INT mask;
3266 if (data_index >= VEC_length (address_cost_data, address_cost_data_list))
3267 VEC_safe_grow_cleared (address_cost_data, heap, address_cost_data_list,
3270 data = VEC_index (address_cost_data, address_cost_data_list, data_index);
3274 HOST_WIDE_INT rat, off = 0;
3275 int old_cse_not_expected, width;
3276 unsigned sym_p, var_p, off_p, rat_p, add_c;
3277 rtx seq, addr, base;
3280 data = (address_cost_data) xcalloc (1, sizeof (*data));
3282 reg1 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 1);
3284 width = GET_MODE_BITSIZE (address_mode) - 1;
3285 if (width > (HOST_BITS_PER_WIDE_INT - 1))
3286 width = HOST_BITS_PER_WIDE_INT - 1;
3287 addr = gen_rtx_fmt_ee (PLUS, address_mode, reg1, NULL_RTX);
3289 for (i = width; i >= 0; i--)
3291 off = -((HOST_WIDE_INT) 1 << i);
3292 XEXP (addr, 1) = gen_int_mode (off, address_mode);
3293 if (memory_address_addr_space_p (mem_mode, addr, as))
3296 data->min_offset = (i == -1? 0 : off);
3298 for (i = width; i >= 0; i--)
3300 off = ((HOST_WIDE_INT) 1 << i) - 1;
3301 XEXP (addr, 1) = gen_int_mode (off, address_mode);
3302 if (memory_address_addr_space_p (mem_mode, addr, as))
3307 data->max_offset = off;
3309 if (dump_file && (dump_flags & TDF_DETAILS))
3311 fprintf (dump_file, "get_address_cost:\n");
3312 fprintf (dump_file, " min offset %s " HOST_WIDE_INT_PRINT_DEC "\n",
3313 GET_MODE_NAME (mem_mode),
3315 fprintf (dump_file, " max offset %s " HOST_WIDE_INT_PRINT_DEC "\n",
3316 GET_MODE_NAME (mem_mode),
3321 for (i = 2; i <= MAX_RATIO; i++)
3322 if (multiplier_allowed_in_address_p (i, mem_mode, as))
3328 /* Compute the cost of various addressing modes. */
3330 reg0 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 1);
3331 reg1 = gen_raw_REG (address_mode, LAST_VIRTUAL_REGISTER + 2);
3333 if (HAVE_PRE_DECREMENT)
3335 addr = gen_rtx_PRE_DEC (address_mode, reg0);
3336 has_predec[mem_mode]
3337 = memory_address_addr_space_p (mem_mode, addr, as);
3339 if (HAVE_POST_DECREMENT)
3341 addr = gen_rtx_POST_DEC (address_mode, reg0);
3342 has_postdec[mem_mode]
3343 = memory_address_addr_space_p (mem_mode, addr, as);
3345 if (HAVE_PRE_INCREMENT)
3347 addr = gen_rtx_PRE_INC (address_mode, reg0);
3348 has_preinc[mem_mode]
3349 = memory_address_addr_space_p (mem_mode, addr, as);
3351 if (HAVE_POST_INCREMENT)
3353 addr = gen_rtx_POST_INC (address_mode, reg0);
3354 has_postinc[mem_mode]
3355 = memory_address_addr_space_p (mem_mode, addr, as);
3357 for (i = 0; i < 16; i++)
3360 var_p = (i >> 1) & 1;
3361 off_p = (i >> 2) & 1;
3362 rat_p = (i >> 3) & 1;
3366 addr = gen_rtx_fmt_ee (MULT, address_mode, addr,
3367 gen_int_mode (rat, address_mode));
3370 addr = gen_rtx_fmt_ee (PLUS, address_mode, addr, reg1);
3374 base = gen_rtx_SYMBOL_REF (address_mode, ggc_strdup (""));
3375 /* ??? We can run into trouble with some backends by presenting
3376 it with symbols which haven't been properly passed through
3377 targetm.encode_section_info. By setting the local bit, we
3378 enhance the probability of things working. */
3379 SYMBOL_REF_FLAGS (base) = SYMBOL_FLAG_LOCAL;
3382 base = gen_rtx_fmt_e (CONST, address_mode,
3384 (PLUS, address_mode, base,
3385 gen_int_mode (off, address_mode)));
3388 base = gen_int_mode (off, address_mode);
3393 addr = gen_rtx_fmt_ee (PLUS, address_mode, addr, base);
3396 /* To avoid splitting addressing modes, pretend that no cse will
3398 old_cse_not_expected = cse_not_expected;
3399 cse_not_expected = true;
3400 addr = memory_address_addr_space (mem_mode, addr, as);
3401 cse_not_expected = old_cse_not_expected;
3405 acost = seq_cost (seq, speed);
3406 acost += address_cost (addr, mem_mode, as, speed);
3410 data->costs[sym_p][var_p][off_p][rat_p] = acost;
3413 /* On some targets, it is quite expensive to load symbol to a register,
3414 which makes addresses that contain symbols look much more expensive.
3415 However, the symbol will have to be loaded in any case before the
3416 loop (and quite likely we have it in register already), so it does not
3417 make much sense to penalize them too heavily. So make some final
3418 tweaks for the SYMBOL_PRESENT modes:
3420 If VAR_PRESENT is false, and the mode obtained by changing symbol to
3421 var is cheaper, use this mode with small penalty.
3422 If VAR_PRESENT is true, try whether the mode with
3423 SYMBOL_PRESENT = false is cheaper even with cost of addition, and
3424 if this is the case, use it. */
3425 add_c = add_cost (address_mode, speed);
3426 for (i = 0; i < 8; i++)
3429 off_p = (i >> 1) & 1;
3430 rat_p = (i >> 2) & 1;
3432 acost = data->costs[0][1][off_p][rat_p] + 1;
3436 if (acost < data->costs[1][var_p][off_p][rat_p])
3437 data->costs[1][var_p][off_p][rat_p] = acost;
3440 if (dump_file && (dump_flags & TDF_DETAILS))
3442 fprintf (dump_file, "Address costs:\n");
3444 for (i = 0; i < 16; i++)
3447 var_p = (i >> 1) & 1;
3448 off_p = (i >> 2) & 1;
3449 rat_p = (i >> 3) & 1;
3451 fprintf (dump_file, " ");
3453 fprintf (dump_file, "sym + ");
3455 fprintf (dump_file, "var + ");
3457 fprintf (dump_file, "cst + ");
3459 fprintf (dump_file, "rat * ");
3461 acost = data->costs[sym_p][var_p][off_p][rat_p];
3462 fprintf (dump_file, "index costs %d\n", acost);
3464 if (has_predec[mem_mode] || has_postdec[mem_mode]
3465 || has_preinc[mem_mode] || has_postinc[mem_mode])
3466 fprintf (dump_file, " May include autoinc/dec\n");
3467 fprintf (dump_file, "\n");
3470 VEC_replace (address_cost_data, address_cost_data_list,
3474 bits = GET_MODE_BITSIZE (address_mode);
3475 mask = ~(~(unsigned HOST_WIDE_INT) 0 << (bits - 1) << 1);
3477 if ((offset >> (bits - 1) & 1))
3482 msize = GET_MODE_SIZE (mem_mode);
3483 autoinc_offset = offset;
3485 autoinc_offset += ratio * cstep;
3486 if (symbol_present || var_present || ratio != 1)
3488 else if ((has_postinc[mem_mode] && autoinc_offset == 0
3490 || (has_postdec[mem_mode] && autoinc_offset == 0
3492 || (has_preinc[mem_mode] && autoinc_offset == msize
3494 || (has_predec[mem_mode] && autoinc_offset == -msize
3495 && msize == -cstep))
3499 offset_p = (s_offset != 0
3500 && data->min_offset <= s_offset
3501 && s_offset <= data->max_offset);
3502 ratio_p = (ratio != 1
3503 && multiplier_allowed_in_address_p (ratio, mem_mode, as));
3505 if (ratio != 1 && !ratio_p)
3506 cost += multiply_by_cost (ratio, address_mode, speed);
3508 if (s_offset && !offset_p && !symbol_present)
3509 cost += add_cost (address_mode, speed);
3512 *may_autoinc = autoinc;
3513 acost = data->costs[symbol_present][var_present][offset_p][ratio_p];
3514 complexity = (symbol_present != 0) + (var_present != 0) + offset_p + ratio_p;
3515 return new_cost (cost + acost, complexity);
3518 /* Calculate the SPEED or size cost of shiftadd EXPR in MODE. MULT is the
3519 the EXPR operand holding the shift. COST0 and COST1 are the costs for
3520 calculating the operands of EXPR. Returns true if successful, and returns
3521 the cost in COST. */
3524 get_shiftadd_cost (tree expr, enum machine_mode mode, comp_cost cost0,
3525 comp_cost cost1, tree mult, bool speed, comp_cost *cost)
3528 tree op1 = TREE_OPERAND (expr, 1);
3529 tree cst = TREE_OPERAND (mult, 1);
3530 tree multop = TREE_OPERAND (mult, 0);
3531 int m = exact_log2 (int_cst_value (cst));
3532 int maxm = MIN (BITS_PER_WORD, GET_MODE_BITSIZE (mode));
3535 if (!(m >= 0 && m < maxm))
3538 sa_cost = (TREE_CODE (expr) != MINUS_EXPR
3539 ? shiftadd_cost[speed][mode][m]
3541 ? shiftsub1_cost[speed][mode][m]
3542 : shiftsub0_cost[speed][mode][m]));
3543 res = new_cost (sa_cost, 0);
3544 res = add_costs (res, mult == op1 ? cost0 : cost1);
3546 STRIP_NOPS (multop);
3547 if (!is_gimple_val (multop))
3548 res = add_costs (res, force_expr_to_var_cost (multop, speed));
3554 /* Estimates cost of forcing expression EXPR into a variable. */
3557 force_expr_to_var_cost (tree expr, bool speed)
3559 static bool costs_initialized = false;
3560 static unsigned integer_cost [2];
3561 static unsigned symbol_cost [2];
3562 static unsigned address_cost [2];
3564 comp_cost cost0, cost1, cost;
3565 enum machine_mode mode;
3567 if (!costs_initialized)
3569 tree type = build_pointer_type (integer_type_node);
3574 var = create_tmp_var_raw (integer_type_node, "test_var");
3575 TREE_STATIC (var) = 1;
3576 x = produce_memory_decl_rtl (var, NULL);
3577 SET_DECL_RTL (var, x);
3579 addr = build1 (ADDR_EXPR, type, var);
3582 for (i = 0; i < 2; i++)
3584 integer_cost[i] = computation_cost (build_int_cst (integer_type_node,
3587 symbol_cost[i] = computation_cost (addr, i) + 1;
3590 = computation_cost (fold_build_pointer_plus_hwi (addr, 2000), i) + 1;
3591 if (dump_file && (dump_flags & TDF_DETAILS))
3593 fprintf (dump_file, "force_expr_to_var_cost %s costs:\n", i ? "speed" : "size");
3594 fprintf (dump_file, " integer %d\n", (int) integer_cost[i]);
3595 fprintf (dump_file, " symbol %d\n", (int) symbol_cost[i]);
3596 fprintf (dump_file, " address %d\n", (int) address_cost[i]);
3597 fprintf (dump_file, " other %d\n", (int) target_spill_cost[i]);
3598 fprintf (dump_file, "\n");
3602 costs_initialized = true;
3607 if (SSA_VAR_P (expr))
3610 if (is_gimple_min_invariant (expr))
3612 if (TREE_CODE (expr) == INTEGER_CST)
3613 return new_cost (integer_cost [speed], 0);
3615 if (TREE_CODE (expr) == ADDR_EXPR)
3617 tree obj = TREE_OPERAND (expr, 0);
3619 if (TREE_CODE (obj) == VAR_DECL
3620 || TREE_CODE (obj) == PARM_DECL
3621 || TREE_CODE (obj) == RESULT_DECL)
3622 return new_cost (symbol_cost [speed], 0);
3625 return new_cost (address_cost [speed], 0);
3628 switch (TREE_CODE (expr))
3630 case POINTER_PLUS_EXPR:
3634 op0 = TREE_OPERAND (expr, 0);
3635 op1 = TREE_OPERAND (expr, 1);
3639 if (is_gimple_val (op0))
3642 cost0 = force_expr_to_var_cost (op0, speed);
3644 if (is_gimple_val (op1))
3647 cost1 = force_expr_to_var_cost (op1, speed);
3652 op0 = TREE_OPERAND (expr, 0);
3656 if (is_gimple_val (op0))
3659 cost0 = force_expr_to_var_cost (op0, speed);
3665 /* Just an arbitrary value, FIXME. */
3666 return new_cost (target_spill_cost[speed], 0);
3669 mode = TYPE_MODE (TREE_TYPE (expr));
3670 switch (TREE_CODE (expr))
3672 case POINTER_PLUS_EXPR:
3676 cost = new_cost (add_cost (mode, speed), 0);
3677 if (TREE_CODE (expr) != NEGATE_EXPR)
3679 tree mult = NULL_TREE;
3681 if (TREE_CODE (op1) == MULT_EXPR)
3683 else if (TREE_CODE (op0) == MULT_EXPR)
3686 if (mult != NULL_TREE
3687 && cst_and_fits_in_hwi (TREE_OPERAND (mult, 1))
3688 && get_shiftadd_cost (expr, mode, cost0, cost1, mult, speed,
3695 if (cst_and_fits_in_hwi (op0))
3696 cost = new_cost (multiply_by_cost (int_cst_value (op0), mode, speed), 0);
3697 else if (cst_and_fits_in_hwi (op1))
3698 cost = new_cost (multiply_by_cost (int_cst_value (op1), mode, speed), 0);
3700 return new_cost (target_spill_cost [speed], 0);
3707 cost = add_costs (cost, cost0);
3708 cost = add_costs (cost, cost1);
3710 /* Bound the cost by target_spill_cost. The parts of complicated
3711 computations often are either loop invariant or at least can
3712 be shared between several iv uses, so letting this grow without
3713 limits would not give reasonable results. */
3714 if (cost.cost > (int) target_spill_cost [speed])
3715 cost.cost = target_spill_cost [speed];
3720 /* Estimates cost of forcing EXPR into a variable. DEPENDS_ON is a set of the
3721 invariants the computation depends on. */
3724 force_var_cost (struct ivopts_data *data,
3725 tree expr, bitmap *depends_on)
3729 fd_ivopts_data = data;
3730 walk_tree (&expr, find_depends, depends_on, NULL);
3733 return force_expr_to_var_cost (expr, data->speed);
3736 /* Estimates cost of expressing address ADDR as var + symbol + offset. The
3737 value of offset is added to OFFSET, SYMBOL_PRESENT and VAR_PRESENT are set
3738 to false if the corresponding part is missing. DEPENDS_ON is a set of the
3739 invariants the computation depends on. */
3742 split_address_cost (struct ivopts_data *data,
3743 tree addr, bool *symbol_present, bool *var_present,
3744 unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
3747 HOST_WIDE_INT bitsize;
3748 HOST_WIDE_INT bitpos;
3750 enum machine_mode mode;
3751 int unsignedp, volatilep;
3753 core = get_inner_reference (addr, &bitsize, &bitpos, &toffset, &mode,
3754 &unsignedp, &volatilep, false);
3757 || bitpos % BITS_PER_UNIT != 0
3758 || TREE_CODE (core) != VAR_DECL)
3760 *symbol_present = false;
3761 *var_present = true;
3762 fd_ivopts_data = data;
3763 walk_tree (&addr, find_depends, depends_on, NULL);
3764 return new_cost (target_spill_cost[data->speed], 0);
3767 *offset += bitpos / BITS_PER_UNIT;
3768 if (TREE_STATIC (core)
3769 || DECL_EXTERNAL (core))
3771 *symbol_present = true;
3772 *var_present = false;
3776 *symbol_present = false;
3777 *var_present = true;
3781 /* Estimates cost of expressing difference of addresses E1 - E2 as
3782 var + symbol + offset. The value of offset is added to OFFSET,
3783 SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding
3784 part is missing. DEPENDS_ON is a set of the invariants the computation
3788 ptr_difference_cost (struct ivopts_data *data,
3789 tree e1, tree e2, bool *symbol_present, bool *var_present,
3790 unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
3792 HOST_WIDE_INT diff = 0;
3793 aff_tree aff_e1, aff_e2;
3796 gcc_assert (TREE_CODE (e1) == ADDR_EXPR);
3798 if (ptr_difference_const (e1, e2, &diff))
3801 *symbol_present = false;
3802 *var_present = false;
3806 if (integer_zerop (e2))
3807 return split_address_cost (data, TREE_OPERAND (e1, 0),
3808 symbol_present, var_present, offset, depends_on);
3810 *symbol_present = false;
3811 *var_present = true;
3813 type = signed_type_for (TREE_TYPE (e1));
3814 tree_to_aff_combination (e1, type, &aff_e1);
3815 tree_to_aff_combination (e2, type, &aff_e2);
3816 aff_combination_scale (&aff_e2, double_int_minus_one);
3817 aff_combination_add (&aff_e1, &aff_e2);
3819 return force_var_cost (data, aff_combination_to_tree (&aff_e1), depends_on);
3822 /* Estimates cost of expressing difference E1 - E2 as
3823 var + symbol + offset. The value of offset is added to OFFSET,
3824 SYMBOL_PRESENT and VAR_PRESENT are set to false if the corresponding
3825 part is missing. DEPENDS_ON is a set of the invariants the computation
3829 difference_cost (struct ivopts_data *data,
3830 tree e1, tree e2, bool *symbol_present, bool *var_present,
3831 unsigned HOST_WIDE_INT *offset, bitmap *depends_on)
3833 enum machine_mode mode = TYPE_MODE (TREE_TYPE (e1));
3834 unsigned HOST_WIDE_INT off1, off2;
3835 aff_tree aff_e1, aff_e2;
3838 e1 = strip_offset (e1, &off1);
3839 e2 = strip_offset (e2, &off2);
3840 *offset += off1 - off2;
3845 if (TREE_CODE (e1) == ADDR_EXPR)
3846 return ptr_difference_cost (data, e1, e2, symbol_present, var_present,
3847 offset, depends_on);
3848 *symbol_present = false;
3850 if (operand_equal_p (e1, e2, 0))
3852 *var_present = false;
3856 *var_present = true;
3858 if (integer_zerop (e2))
3859 return force_var_cost (data, e1, depends_on);
3861 if (integer_zerop (e1))
3863 comp_cost cost = force_var_cost (data, e2, depends_on);
3864 cost.cost += multiply_by_cost (-1, mode, data->speed);
3868 type = signed_type_for (TREE_TYPE (e1));
3869 tree_to_aff_combination (e1, type, &aff_e1);
3870 tree_to_aff_combination (e2, type, &aff_e2);
3871 aff_combination_scale (&aff_e2, double_int_minus_one);
3872 aff_combination_add (&aff_e1, &aff_e2);
3874 return force_var_cost (data, aff_combination_to_tree (&aff_e1), depends_on);
3877 /* Returns true if AFF1 and AFF2 are identical. */
3880 compare_aff_trees (aff_tree *aff1, aff_tree *aff2)
3884 if (aff1->n != aff2->n)
3887 for (i = 0; i < aff1->n; i++)
3889 if (double_int_cmp (aff1->elts[i].coef, aff2->elts[i].coef, 0) != 0)
3892 if (!operand_equal_p (aff1->elts[i].val, aff2->elts[i].val, 0))
3898 /* Stores EXPR in DATA->inv_expr_tab, and assigns it an inv_expr_id. */
3901 get_expr_id (struct ivopts_data *data, tree expr)
3903 struct iv_inv_expr_ent ent;
3904 struct iv_inv_expr_ent **slot;
3907 ent.hash = iterative_hash_expr (expr, 0);
3908 slot = (struct iv_inv_expr_ent **) htab_find_slot (data->inv_expr_tab,
3913 *slot = XNEW (struct iv_inv_expr_ent);
3914 (*slot)->expr = expr;
3915 (*slot)->hash = ent.hash;
3916 (*slot)->id = data->inv_expr_id++;
3920 /* Returns the pseudo expr id if expression UBASE - RATIO * CBASE
3921 requires a new compiler generated temporary. Returns -1 otherwise.
3922 ADDRESS_P is a flag indicating if the expression is for address
3926 get_loop_invariant_expr_id (struct ivopts_data *data, tree ubase,
3927 tree cbase, HOST_WIDE_INT ratio,
3930 aff_tree ubase_aff, cbase_aff;
3938 if ((TREE_CODE (ubase) == INTEGER_CST)
3939 && (TREE_CODE (cbase) == INTEGER_CST))
3942 /* Strips the constant part. */
3943 if (TREE_CODE (ubase) == PLUS_EXPR
3944 || TREE_CODE (ubase) == MINUS_EXPR
3945 || TREE_CODE (ubase) == POINTER_PLUS_EXPR)
3947 if (TREE_CODE (TREE_OPERAND (ubase, 1)) == INTEGER_CST)
3948 ubase = TREE_OPERAND (ubase, 0);
3951 /* Strips the constant part. */
3952 if (TREE_CODE (cbase) == PLUS_EXPR
3953 || TREE_CODE (cbase) == MINUS_EXPR
3954 || TREE_CODE (cbase) == POINTER_PLUS_EXPR)
3956 if (TREE_CODE (TREE_OPERAND (cbase, 1)) == INTEGER_CST)
3957 cbase = TREE_OPERAND (cbase, 0);
3962 if (((TREE_CODE (ubase) == SSA_NAME)
3963 || (TREE_CODE (ubase) == ADDR_EXPR
3964 && is_gimple_min_invariant (ubase)))
3965 && (TREE_CODE (cbase) == INTEGER_CST))
3968 if (((TREE_CODE (cbase) == SSA_NAME)
3969 || (TREE_CODE (cbase) == ADDR_EXPR
3970 && is_gimple_min_invariant (cbase)))
3971 && (TREE_CODE (ubase) == INTEGER_CST))
3977 if(operand_equal_p (ubase, cbase, 0))
3980 if (TREE_CODE (ubase) == ADDR_EXPR
3981 && TREE_CODE (cbase) == ADDR_EXPR)
3985 usym = TREE_OPERAND (ubase, 0);
3986 csym = TREE_OPERAND (cbase, 0);
3987 if (TREE_CODE (usym) == ARRAY_REF)
3989 tree ind = TREE_OPERAND (usym, 1);
3990 if (TREE_CODE (ind) == INTEGER_CST
3991 && host_integerp (ind, 0)
3992 && TREE_INT_CST_LOW (ind) == 0)
3993 usym = TREE_OPERAND (usym, 0);
3995 if (TREE_CODE (csym) == ARRAY_REF)
3997 tree ind = TREE_OPERAND (csym, 1);
3998 if (TREE_CODE (ind) == INTEGER_CST
3999 && host_integerp (ind, 0)
4000 && TREE_INT_CST_LOW (ind) == 0)
4001 csym = TREE_OPERAND (csym, 0);
4003 if (operand_equal_p (usym, csym, 0))
4006 /* Now do more complex comparison */
4007 tree_to_aff_combination (ubase, TREE_TYPE (ubase), &ubase_aff);
4008 tree_to_aff_combination (cbase, TREE_TYPE (cbase), &cbase_aff);
4009 if (compare_aff_trees (&ubase_aff, &cbase_aff))
4013 tree_to_aff_combination (ub, TREE_TYPE (ub), &ubase_aff);
4014 tree_to_aff_combination (cb, TREE_TYPE (cb), &cbase_aff);
4016 aff_combination_scale (&cbase_aff, shwi_to_double_int (-1 * ratio));
4017 aff_combination_add (&ubase_aff, &cbase_aff);
4018 expr = aff_combination_to_tree (&ubase_aff);
4019 return get_expr_id (data, expr);
4024 /* Determines the cost of the computation by that USE is expressed
4025 from induction variable CAND. If ADDRESS_P is true, we just need
4026 to create an address from it, otherwise we want to get it into
4027 register. A set of invariants we depend on is stored in
4028 DEPENDS_ON. AT is the statement at that the value is computed.
4029 If CAN_AUTOINC is nonnull, use it to record whether autoinc
4030 addressing is likely. */
4033 get_computation_cost_at (struct ivopts_data *data,
4034 struct iv_use *use, struct iv_cand *cand,
4035 bool address_p, bitmap *depends_on, gimple at,
4039 tree ubase = use->iv->base, ustep = use->iv->step;
4041 tree utype = TREE_TYPE (ubase), ctype;
4042 unsigned HOST_WIDE_INT cstepi, offset = 0;
4043 HOST_WIDE_INT ratio, aratio;
4044 bool var_present, symbol_present, stmt_is_after_inc;
4047 bool speed = optimize_bb_for_speed_p (gimple_bb (at));
4051 /* Only consider real candidates. */
4053 return infinite_cost;
4055 cbase = cand->iv->base;
4056 cstep = cand->iv->step;
4057 ctype = TREE_TYPE (cbase);
4059 if (TYPE_PRECISION (utype) > TYPE_PRECISION (ctype))
4061 /* We do not have a precision to express the values of use. */
4062 return infinite_cost;
4067 /* Do not try to express address of an object with computation based
4068 on address of a different object. This may cause problems in rtl
4069 level alias analysis (that does not expect this to be happening,
4070 as this is illegal in C), and would be unlikely to be useful
4072 if (use->iv->base_object
4073 && cand->iv->base_object
4074 && !operand_equal_p (use->iv->base_object, cand->iv->base_object, 0))
4075 return infinite_cost;
4078 if (TYPE_PRECISION (utype) < TYPE_PRECISION (ctype))
4080 /* TODO -- add direct handling of this case. */
4084 /* CSTEPI is removed from the offset in case statement is after the
4085 increment. If the step is not constant, we use zero instead.
4086 This is a bit imprecise (there is the extra addition), but
4087 redundancy elimination is likely to transform the code so that
4088 it uses value of the variable before increment anyway,
4089 so it is not that much unrealistic. */
4090 if (cst_and_fits_in_hwi (cstep))
4091 cstepi = int_cst_value (cstep);
4095 if (!constant_multiple_of (ustep, cstep, &rat))
4096 return infinite_cost;
4098 if (double_int_fits_in_shwi_p (rat))
4099 ratio = double_int_to_shwi (rat);
4101 return infinite_cost;
4104 ctype = TREE_TYPE (cbase);
4106 stmt_is_after_inc = stmt_after_increment (data->current_loop, cand, at);
4108 /* use = ubase + ratio * (var - cbase). If either cbase is a constant
4109 or ratio == 1, it is better to handle this like
4111 ubase - ratio * cbase + ratio * var
4113 (also holds in the case ratio == -1, TODO. */
4115 if (cst_and_fits_in_hwi (cbase))
4117 offset = - ratio * int_cst_value (cbase);
4118 cost = difference_cost (data,
4119 ubase, build_int_cst (utype, 0),
4120 &symbol_present, &var_present, &offset,
4122 cost.cost /= avg_loop_niter (data->current_loop);
4124 else if (ratio == 1)
4126 tree real_cbase = cbase;
4128 /* Check to see if any adjustment is needed. */
4129 if (cstepi == 0 && stmt_is_after_inc)
4131 aff_tree real_cbase_aff;
4134 tree_to_aff_combination (cbase, TREE_TYPE (real_cbase),
4136 tree_to_aff_combination (cstep, TREE_TYPE (cstep), &cstep_aff);
4138 aff_combination_add (&real_cbase_aff, &cstep_aff);
4139 real_cbase = aff_combination_to_tree (&real_cbase_aff);
4142 cost = difference_cost (data,
4144 &symbol_present, &var_present, &offset,
4146 cost.cost /= avg_loop_niter (data->current_loop);
4149 && !POINTER_TYPE_P (ctype)
4150 && multiplier_allowed_in_address_p
4151 (ratio, TYPE_MODE (TREE_TYPE (utype)),
4152 TYPE_ADDR_SPACE (TREE_TYPE (utype))))
4155 = fold_build2 (MULT_EXPR, ctype, cbase, build_int_cst (ctype, ratio));
4156 cost = difference_cost (data,
4158 &symbol_present, &var_present, &offset,
4160 cost.cost /= avg_loop_niter (data->current_loop);
4164 cost = force_var_cost (data, cbase, depends_on);
4165 cost = add_costs (cost,
4166 difference_cost (data,
4167 ubase, build_int_cst (utype, 0),
4168 &symbol_present, &var_present,
4169 &offset, depends_on));
4170 cost.cost /= avg_loop_niter (data->current_loop);
4171 cost.cost += add_cost (TYPE_MODE (ctype), data->speed);
4177 get_loop_invariant_expr_id (data, ubase, cbase, ratio, address_p);
4178 /* Clear depends on. */
4179 if (*inv_expr_id != -1 && depends_on && *depends_on)
4180 bitmap_clear (*depends_on);
4183 /* If we are after the increment, the value of the candidate is higher by
4185 if (stmt_is_after_inc)
4186 offset -= ratio * cstepi;
4188 /* Now the computation is in shape symbol + var1 + const + ratio * var2.
4189 (symbol/var1/const parts may be omitted). If we are looking for an
4190 address, find the cost of addressing this. */
4192 return add_costs (cost,
4193 get_address_cost (symbol_present, var_present,
4194 offset, ratio, cstepi,
4195 TYPE_MODE (TREE_TYPE (utype)),
4196 TYPE_ADDR_SPACE (TREE_TYPE (utype)),
4197 speed, stmt_is_after_inc,
4200 /* Otherwise estimate the costs for computing the expression. */
4201 if (!symbol_present && !var_present && !offset)
4204 cost.cost += multiply_by_cost (ratio, TYPE_MODE (ctype), speed);
4208 /* Symbol + offset should be compile-time computable so consider that they
4209 are added once to the variable, if present. */
4210 if (var_present && (symbol_present || offset))
4211 cost.cost += adjust_setup_cost (data,
4212 add_cost (TYPE_MODE (ctype), speed));
4214 /* Having offset does not affect runtime cost in case it is added to
4215 symbol, but it increases complexity. */
4219 cost.cost += add_cost (TYPE_MODE (ctype), speed);
4221 aratio = ratio > 0 ? ratio : -ratio;
4223 cost.cost += multiply_by_cost (aratio, TYPE_MODE (ctype), speed);
4228 *can_autoinc = false;
4231 /* Just get the expression, expand it and measure the cost. */
4232 tree comp = get_computation_at (data->current_loop, use, cand, at);
4235 return infinite_cost;
4238 comp = build_simple_mem_ref (comp);
4240 return new_cost (computation_cost (comp, speed), 0);
4244 /* Determines the cost of the computation by that USE is expressed
4245 from induction variable CAND. If ADDRESS_P is true, we just need
4246 to create an address from it, otherwise we want to get it into
4247 register. A set of invariants we depend on is stored in
4248 DEPENDS_ON. If CAN_AUTOINC is nonnull, use it to record whether
4249 autoinc addressing is likely. */
4252 get_computation_cost (struct ivopts_data *data,
4253 struct iv_use *use, struct iv_cand *cand,
4254 bool address_p, bitmap *depends_on,
4255 bool *can_autoinc, int *inv_expr_id)
4257 return get_computation_cost_at (data,
4258 use, cand, address_p, depends_on, use->stmt,
4259 can_autoinc, inv_expr_id);
4262 /* Determines cost of basing replacement of USE on CAND in a generic
4266 determine_use_iv_cost_generic (struct ivopts_data *data,
4267 struct iv_use *use, struct iv_cand *cand)
4271 int inv_expr_id = -1;
4273 /* The simple case first -- if we need to express value of the preserved
4274 original biv, the cost is 0. This also prevents us from counting the
4275 cost of increment twice -- once at this use and once in the cost of
4277 if (cand->pos == IP_ORIGINAL
4278 && cand->incremented_at == use->stmt)
4280 set_use_iv_cost (data, use, cand, zero_cost, NULL, NULL_TREE, -1);
4284 cost = get_computation_cost (data, use, cand, false, &depends_on,
4285 NULL, &inv_expr_id);
4287 set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE,
4290 return !infinite_cost_p (cost);
4293 /* Determines cost of basing replacement of USE on CAND in an address. */
4296 determine_use_iv_cost_address (struct ivopts_data *data,
4297 struct iv_use *use, struct iv_cand *cand)
4301 int inv_expr_id = -1;
4302 comp_cost cost = get_computation_cost (data, use, cand, true, &depends_on,
4303 &can_autoinc, &inv_expr_id);
4305 if (cand->ainc_use == use)
4308 cost.cost -= cand->cost_step;
4309 /* If we generated the candidate solely for exploiting autoincrement
4310 opportunities, and it turns out it can't be used, set the cost to
4311 infinity to make sure we ignore it. */
4312 else if (cand->pos == IP_AFTER_USE || cand->pos == IP_BEFORE_USE)
4313 cost = infinite_cost;
4315 set_use_iv_cost (data, use, cand, cost, depends_on, NULL_TREE,
4318 return !infinite_cost_p (cost);
4321 /* Computes value of candidate CAND at position AT in iteration NITER, and
4322 stores it to VAL. */
4325 cand_value_at (struct loop *loop, struct iv_cand *cand, gimple at, tree niter,
4328 aff_tree step, delta, nit;
4329 struct iv *iv = cand->iv;
4330 tree type = TREE_TYPE (iv->base);
4331 tree steptype = type;
4332 if (POINTER_TYPE_P (type))
4333 steptype = sizetype;
4335 tree_to_aff_combination (iv->step, steptype, &step);
4336 tree_to_aff_combination (niter, TREE_TYPE (niter), &nit);
4337 aff_combination_convert (&nit, steptype);
4338 aff_combination_mult (&nit, &step, &delta);
4339 if (stmt_after_increment (loop, cand, at))
4340 aff_combination_add (&delta, &step);
4342 tree_to_aff_combination (iv->base, type, val);
4343 aff_combination_add (val, &delta);
4346 /* Returns period of induction variable iv. */
4349 iv_period (struct iv *iv)
4351 tree step = iv->step, period, type;
4354 gcc_assert (step && TREE_CODE (step) == INTEGER_CST);
4356 type = unsigned_type_for (TREE_TYPE (step));
4357 /* Period of the iv is lcm (step, type_range)/step -1,
4358 i.e., N*type_range/step - 1. Since type range is power
4359 of two, N == (step >> num_of_ending_zeros_binary (step),
4360 so the final result is
4362 (type_range >> num_of_ending_zeros_binary (step)) - 1
4365 pow2div = num_ending_zeros (step);
4367 period = build_low_bits_mask (type,
4368 (TYPE_PRECISION (type)
4369 - tree_low_cst (pow2div, 1)));
4374 /* Returns the comparison operator used when eliminating the iv USE. */
4376 static enum tree_code
4377 iv_elimination_compare (struct ivopts_data *data, struct iv_use *use)
4379 struct loop *loop = data->current_loop;
4383 ex_bb = gimple_bb (use->stmt);
4384 exit = EDGE_SUCC (ex_bb, 0);
4385 if (flow_bb_inside_loop_p (loop, exit->dest))
4386 exit = EDGE_SUCC (ex_bb, 1);
4388 return (exit->flags & EDGE_TRUE_VALUE ? EQ_EXPR : NE_EXPR);
4391 /* Check whether it is possible to express the condition in USE by comparison
4392 of candidate CAND. If so, store the value compared with to BOUND. */
4395 may_eliminate_iv (struct ivopts_data *data,
4396 struct iv_use *use, struct iv_cand *cand, tree *bound)
4401 struct loop *loop = data->current_loop;
4403 struct tree_niter_desc *desc = NULL;
4405 if (TREE_CODE (cand->iv->step) != INTEGER_CST)
4408 /* For now works only for exits that dominate the loop latch.
4409 TODO: extend to other conditions inside loop body. */
4410 ex_bb = gimple_bb (use->stmt);
4411 if (use->stmt != last_stmt (ex_bb)
4412 || gimple_code (use->stmt) != GIMPLE_COND
4413 || !dominated_by_p (CDI_DOMINATORS, loop->latch, ex_bb))
4416 exit = EDGE_SUCC (ex_bb, 0);
4417 if (flow_bb_inside_loop_p (loop, exit->dest))
4418 exit = EDGE_SUCC (ex_bb, 1);
4419 if (flow_bb_inside_loop_p (loop, exit->dest))
4422 nit = niter_for_exit (data, exit, &desc);
4426 /* Determine whether we can use the variable to test the exit condition.
4427 This is the case iff the period of the induction variable is greater
4428 than the number of iterations for which the exit condition is true. */
4429 period = iv_period (cand->iv);
4431 /* If the number of iterations is constant, compare against it directly. */
4432 if (TREE_CODE (nit) == INTEGER_CST)
4434 /* See cand_value_at. */
4435 if (stmt_after_increment (loop, cand, use->stmt))
4437 if (!tree_int_cst_lt (nit, period))
4442 if (tree_int_cst_lt (period, nit))
4447 /* If not, and if this is the only possible exit of the loop, see whether
4448 we can get a conservative estimate on the number of iterations of the
4449 entire loop and compare against that instead. */
4452 double_int period_value, max_niter;
4454 max_niter = desc->max;
4455 if (stmt_after_increment (loop, cand, use->stmt))
4456 max_niter = double_int_add (max_niter, double_int_one);
4457 period_value = tree_to_double_int (period);
4458 if (double_int_ucmp (max_niter, period_value) > 0)
4460 /* See if we can take advantage of infered loop bound information. */
4461 if (loop_only_exit_p (loop, exit))
4463 if (!estimated_loop_iterations (loop, true, &max_niter))
4465 /* The loop bound is already adjusted by adding 1. */
4466 if (double_int_ucmp (max_niter, period_value) > 0)
4474 cand_value_at (loop, cand, use->stmt, nit, &bnd);
4476 *bound = aff_combination_to_tree (&bnd);
4477 /* It is unlikely that computing the number of iterations using division
4478 would be more profitable than keeping the original induction variable. */
4479 if (expression_expensive_p (*bound))
4484 /* Calculates the cost of BOUND, if it is a PARM_DECL. A PARM_DECL must
4485 be copied, if is is used in the loop body and DATA->body_includes_call. */
4488 parm_decl_cost (struct ivopts_data *data, tree bound)
4490 tree sbound = bound;
4491 STRIP_NOPS (sbound);
4493 if (TREE_CODE (sbound) == SSA_NAME
4494 && TREE_CODE (SSA_NAME_VAR (sbound)) == PARM_DECL
4495 && gimple_nop_p (SSA_NAME_DEF_STMT (sbound))
4496 && data->body_includes_call)
4497 return COSTS_N_INSNS (1);
4502 /* Determines cost of basing replacement of USE on CAND in a condition. */
4505 determine_use_iv_cost_condition (struct ivopts_data *data,
4506 struct iv_use *use, struct iv_cand *cand)
4508 tree bound = NULL_TREE;
4510 bitmap depends_on_elim = NULL, depends_on_express = NULL, depends_on;
4511 comp_cost elim_cost, express_cost, cost, bound_cost;
4513 int elim_inv_expr_id = -1, express_inv_expr_id = -1, inv_expr_id;
4514 tree *control_var, *bound_cst;
4516 /* Only consider real candidates. */
4519 set_use_iv_cost (data, use, cand, infinite_cost, NULL, NULL_TREE, -1);
4523 /* Try iv elimination. */
4524 if (may_eliminate_iv (data, use, cand, &bound))
4526 elim_cost = force_var_cost (data, bound, &depends_on_elim);
4527 if (elim_cost.cost == 0)
4528 elim_cost.cost = parm_decl_cost (data, bound);
4529 else if (TREE_CODE (bound) == INTEGER_CST)
4531 /* If we replace a loop condition 'i < n' with 'p < base + n',
4532 depends_on_elim will have 'base' and 'n' set, which implies
4533 that both 'base' and 'n' will be live during the loop. More likely,
4534 'base + n' will be loop invariant, resulting in only one live value
4535 during the loop. So in that case we clear depends_on_elim and set
4536 elim_inv_expr_id instead. */
4537 if (depends_on_elim && bitmap_count_bits (depends_on_elim) > 1)
4539 elim_inv_expr_id = get_expr_id (data, bound);
4540 bitmap_clear (depends_on_elim);
4542 /* The bound is a loop invariant, so it will be only computed
4544 elim_cost.cost = adjust_setup_cost (data, elim_cost.cost);
4547 elim_cost = infinite_cost;
4549 /* Try expressing the original giv. If it is compared with an invariant,
4550 note that we cannot get rid of it. */
4551 ok = extract_cond_operands (data, use->stmt, &control_var, &bound_cst,
4555 /* When the condition is a comparison of the candidate IV against
4556 zero, prefer this IV.
4558 TODO: The constant that we're substracting from the cost should
4559 be target-dependent. This information should be added to the
4560 target costs for each backend. */
4561 if (!infinite_cost_p (elim_cost) /* Do not try to decrease infinite! */
4562 && integer_zerop (*bound_cst)
4563 && (operand_equal_p (*control_var, cand->var_after, 0)
4564 || operand_equal_p (*control_var, cand->var_before, 0)))
4565 elim_cost.cost -= 1;
4567 express_cost = get_computation_cost (data, use, cand, false,
4568 &depends_on_express, NULL,
4569 &express_inv_expr_id);
4570 fd_ivopts_data = data;
4571 walk_tree (&cmp_iv->base, find_depends, &depends_on_express, NULL);
4573 /* Count the cost of the original bound as well. */
4574 bound_cost = force_var_cost (data, *bound_cst, NULL);
4575 if (bound_cost.cost == 0)
4576 bound_cost.cost = parm_decl_cost (data, *bound_cst);
4577 else if (TREE_CODE (*bound_cst) == INTEGER_CST)
4578 bound_cost.cost = 0;
4579 express_cost.cost += bound_cost.cost;
4581 /* Choose the better approach, preferring the eliminated IV. */
4582 if (compare_costs (elim_cost, express_cost) <= 0)
4585 depends_on = depends_on_elim;
4586 depends_on_elim = NULL;
4587 inv_expr_id = elim_inv_expr_id;
4591 cost = express_cost;
4592 depends_on = depends_on_express;
4593 depends_on_express = NULL;
4595 inv_expr_id = express_inv_expr_id;
4598 set_use_iv_cost (data, use, cand, cost, depends_on, bound, inv_expr_id);
4600 if (depends_on_elim)
4601 BITMAP_FREE (depends_on_elim);
4602 if (depends_on_express)
4603 BITMAP_FREE (depends_on_express);
4605 return !infinite_cost_p (cost);
4608 /* Determines cost of basing replacement of USE on CAND. Returns false
4609 if USE cannot be based on CAND. */
4612 determine_use_iv_cost (struct ivopts_data *data,
4613 struct iv_use *use, struct iv_cand *cand)
4617 case USE_NONLINEAR_EXPR:
4618 return determine_use_iv_cost_generic (data, use, cand);
4621 return determine_use_iv_cost_address (data, use, cand);
4624 return determine_use_iv_cost_condition (data, use, cand);
4631 /* Return true if get_computation_cost indicates that autoincrement is
4632 a possibility for the pair of USE and CAND, false otherwise. */
4635 autoinc_possible_for_pair (struct ivopts_data *data, struct iv_use *use,
4636 struct iv_cand *cand)
4642 if (use->type != USE_ADDRESS)
4645 cost = get_computation_cost (data, use, cand, true, &depends_on,
4646 &can_autoinc, NULL);
4648 BITMAP_FREE (depends_on);
4650 return !infinite_cost_p (cost) && can_autoinc;
4653 /* Examine IP_ORIGINAL candidates to see if they are incremented next to a
4654 use that allows autoincrement, and set their AINC_USE if possible. */
4657 set_autoinc_for_original_candidates (struct ivopts_data *data)
4661 for (i = 0; i < n_iv_cands (data); i++)
4663 struct iv_cand *cand = iv_cand (data, i);
4664 struct iv_use *closest = NULL;
4665 if (cand->pos != IP_ORIGINAL)
4667 for (j = 0; j < n_iv_uses (data); j++)
4669 struct iv_use *use = iv_use (data, j);
4670 unsigned uid = gimple_uid (use->stmt);
4671 if (gimple_bb (use->stmt) != gimple_bb (cand->incremented_at)
4672 || uid > gimple_uid (cand->incremented_at))
4674 if (closest == NULL || uid > gimple_uid (closest->stmt))
4677 if (closest == NULL || !autoinc_possible_for_pair (data, closest, cand))
4679 cand->ainc_use = closest;
4683 /* Finds the candidates for the induction variables. */
4686 find_iv_candidates (struct ivopts_data *data)
4688 /* Add commonly used ivs. */
4689 add_standard_iv_candidates (data);
4691 /* Add old induction variables. */
4692 add_old_ivs_candidates (data);
4694 /* Add induction variables derived from uses. */
4695 add_derived_ivs_candidates (data);
4697 set_autoinc_for_original_candidates (data);
4699 /* Record the important candidates. */
4700 record_important_candidates (data);
4703 /* Determines costs of basing the use of the iv on an iv candidate. */
4706 determine_use_iv_costs (struct ivopts_data *data)
4710 struct iv_cand *cand;
4711 bitmap to_clear = BITMAP_ALLOC (NULL);
4713 alloc_use_cost_map (data);
4715 for (i = 0; i < n_iv_uses (data); i++)
4717 use = iv_use (data, i);
4719 if (data->consider_all_candidates)
4721 for (j = 0; j < n_iv_cands (data); j++)
4723 cand = iv_cand (data, j);
4724 determine_use_iv_cost (data, use, cand);
4731 EXECUTE_IF_SET_IN_BITMAP (use->related_cands, 0, j, bi)
4733 cand = iv_cand (data, j);
4734 if (!determine_use_iv_cost (data, use, cand))
4735 bitmap_set_bit (to_clear, j);
4738 /* Remove the candidates for that the cost is infinite from
4739 the list of related candidates. */
4740 bitmap_and_compl_into (use->related_cands, to_clear);
4741 bitmap_clear (to_clear);
4745 BITMAP_FREE (to_clear);
4747 if (dump_file && (dump_flags & TDF_DETAILS))
4749 fprintf (dump_file, "Use-candidate costs:\n");
4751 for (i = 0; i < n_iv_uses (data); i++)
4753 use = iv_use (data, i);
4755 fprintf (dump_file, "Use %d:\n", i);
4756 fprintf (dump_file, " cand\tcost\tcompl.\tdepends on\n");
4757 for (j = 0; j < use->n_map_members; j++)
4759 if (!use->cost_map[j].cand
4760 || infinite_cost_p (use->cost_map[j].cost))
4763 fprintf (dump_file, " %d\t%d\t%d\t",
4764 use->cost_map[j].cand->id,
4765 use->cost_map[j].cost.cost,
4766 use->cost_map[j].cost.complexity);
4767 if (use->cost_map[j].depends_on)
4768 bitmap_print (dump_file,
4769 use->cost_map[j].depends_on, "","");
4770 if (use->cost_map[j].inv_expr_id != -1)
4771 fprintf (dump_file, " inv_expr:%d", use->cost_map[j].inv_expr_id);
4772 fprintf (dump_file, "\n");
4775 fprintf (dump_file, "\n");
4777 fprintf (dump_file, "\n");
4781 /* Determines cost of the candidate CAND. */
4784 determine_iv_cost (struct ivopts_data *data, struct iv_cand *cand)
4786 comp_cost cost_base;
4787 unsigned cost, cost_step;
4796 /* There are two costs associated with the candidate -- its increment
4797 and its initialization. The second is almost negligible for any loop
4798 that rolls enough, so we take it just very little into account. */
4800 base = cand->iv->base;
4801 cost_base = force_var_cost (data, base, NULL);
4802 /* It will be exceptional that the iv register happens to be initialized with
4803 the proper value at no cost. In general, there will at least be a regcopy
4805 if (cost_base.cost == 0)
4806 cost_base.cost = COSTS_N_INSNS (1);
4807 cost_step = add_cost (TYPE_MODE (TREE_TYPE (base)), data->speed);
4809 cost = cost_step + adjust_setup_cost (data, cost_base.cost);
4811 /* Prefer the original ivs unless we may gain something by replacing it.
4812 The reason is to make debugging simpler; so this is not relevant for
4813 artificial ivs created by other optimization passes. */
4814 if (cand->pos != IP_ORIGINAL
4815 || DECL_ARTIFICIAL (SSA_NAME_VAR (cand->var_before)))
4818 /* Prefer not to insert statements into latch unless there are some
4819 already (so that we do not create unnecessary jumps). */
4820 if (cand->pos == IP_END
4821 && empty_block_p (ip_end_pos (data->current_loop)))
4825 cand->cost_step = cost_step;
4828 /* Determines costs of computation of the candidates. */
4831 determine_iv_costs (struct ivopts_data *data)
4835 if (dump_file && (dump_flags & TDF_DETAILS))
4837 fprintf (dump_file, "Candidate costs:\n");
4838 fprintf (dump_file, " cand\tcost\n");
4841 for (i = 0; i < n_iv_cands (data); i++)
4843 struct iv_cand *cand = iv_cand (data, i);
4845 determine_iv_cost (data, cand);
4847 if (dump_file && (dump_flags & TDF_DETAILS))
4848 fprintf (dump_file, " %d\t%d\n", i, cand->cost);
4851 if (dump_file && (dump_flags & TDF_DETAILS))
4852 fprintf (dump_file, "\n");
4855 /* Calculates cost for having SIZE induction variables. */
4858 ivopts_global_cost_for_size (struct ivopts_data *data, unsigned size)
4860 /* We add size to the cost, so that we prefer eliminating ivs
4862 return size + estimate_reg_pressure_cost (size, data->regs_used, data->speed,
4863 data->body_includes_call);
4866 /* For each size of the induction variable set determine the penalty. */
4869 determine_set_costs (struct ivopts_data *data)
4873 gimple_stmt_iterator psi;
4875 struct loop *loop = data->current_loop;
4878 if (dump_file && (dump_flags & TDF_DETAILS))
4880 fprintf (dump_file, "Global costs:\n");
4881 fprintf (dump_file, " target_avail_regs %d\n", target_avail_regs);
4882 fprintf (dump_file, " target_clobbered_regs %d\n", target_clobbered_regs);
4883 fprintf (dump_file, " target_reg_cost %d\n", target_reg_cost[data->speed]);
4884 fprintf (dump_file, " target_spill_cost %d\n", target_spill_cost[data->speed]);
4888 for (psi = gsi_start_phis (loop->header); !gsi_end_p (psi); gsi_next (&psi))
4890 phi = gsi_stmt (psi);
4891 op = PHI_RESULT (phi);
4893 if (!is_gimple_reg (op))
4896 if (get_iv (data, op))
4902 EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi)
4904 struct version_info *info = ver_info (data, j);
4906 if (info->inv_id && info->has_nonlin_use)
4910 data->regs_used = n;
4911 if (dump_file && (dump_flags & TDF_DETAILS))
4912 fprintf (dump_file, " regs_used %d\n", n);
4914 if (dump_file && (dump_flags & TDF_DETAILS))
4916 fprintf (dump_file, " cost for size:\n");
4917 fprintf (dump_file, " ivs\tcost\n");
4918 for (j = 0; j <= 2 * target_avail_regs; j++)
4919 fprintf (dump_file, " %d\t%d\n", j,
4920 ivopts_global_cost_for_size (data, j));
4921 fprintf (dump_file, "\n");
4925 /* Returns true if A is a cheaper cost pair than B. */
4928 cheaper_cost_pair (struct cost_pair *a, struct cost_pair *b)
4938 cmp = compare_costs (a->cost, b->cost);
4945 /* In case the costs are the same, prefer the cheaper candidate. */
4946 if (a->cand->cost < b->cand->cost)
4953 /* Returns candidate by that USE is expressed in IVS. */
4955 static struct cost_pair *
4956 iv_ca_cand_for_use (struct iv_ca *ivs, struct iv_use *use)
4958 return ivs->cand_for_use[use->id];
4961 /* Computes the cost field of IVS structure. */
4964 iv_ca_recount_cost (struct ivopts_data *data, struct iv_ca *ivs)
4966 comp_cost cost = ivs->cand_use_cost;
4968 cost.cost += ivs->cand_cost;
4970 cost.cost += ivopts_global_cost_for_size (data,
4971 ivs->n_regs + ivs->num_used_inv_expr);
4976 /* Remove invariants in set INVS to set IVS. */
4979 iv_ca_set_remove_invariants (struct iv_ca *ivs, bitmap invs)
4987 EXECUTE_IF_SET_IN_BITMAP (invs, 0, iid, bi)
4989 ivs->n_invariant_uses[iid]--;
4990 if (ivs->n_invariant_uses[iid] == 0)
4995 /* Set USE not to be expressed by any candidate in IVS. */
4998 iv_ca_set_no_cp (struct ivopts_data *data, struct iv_ca *ivs,
5001 unsigned uid = use->id, cid;
5002 struct cost_pair *cp;
5004 cp = ivs->cand_for_use[uid];
5010 ivs->cand_for_use[uid] = NULL;
5011 ivs->n_cand_uses[cid]--;
5013 if (ivs->n_cand_uses[cid] == 0)
5015 bitmap_clear_bit (ivs->cands, cid);
5016 /* Do not count the pseudocandidates. */
5020 ivs->cand_cost -= cp->cand->cost;
5022 iv_ca_set_remove_invariants (ivs, cp->cand->depends_on);
5025 ivs->cand_use_cost = sub_costs (ivs->cand_use_cost, cp->cost);
5027 iv_ca_set_remove_invariants (ivs, cp->depends_on);
5029 if (cp->inv_expr_id != -1)
5031 ivs->used_inv_expr[cp->inv_expr_id]--;
5032 if (ivs->used_inv_expr[cp->inv_expr_id] == 0)
5033 ivs->num_used_inv_expr--;
5035 iv_ca_recount_cost (data, ivs);
5038 /* Add invariants in set INVS to set IVS. */
5041 iv_ca_set_add_invariants (struct iv_ca *ivs, bitmap invs)
5049 EXECUTE_IF_SET_IN_BITMAP (invs, 0, iid, bi)
5051 ivs->n_invariant_uses[iid]++;
5052 if (ivs->n_invariant_uses[iid] == 1)
5057 /* Set cost pair for USE in set IVS to CP. */
5060 iv_ca_set_cp (struct ivopts_data *data, struct iv_ca *ivs,
5061 struct iv_use *use, struct cost_pair *cp)
5063 unsigned uid = use->id, cid;
5065 if (ivs->cand_for_use[uid] == cp)
5068 if (ivs->cand_for_use[uid])
5069 iv_ca_set_no_cp (data, ivs, use);
5076 ivs->cand_for_use[uid] = cp;
5077 ivs->n_cand_uses[cid]++;
5078 if (ivs->n_cand_uses[cid] == 1)
5080 bitmap_set_bit (ivs->cands, cid);
5081 /* Do not count the pseudocandidates. */
5085 ivs->cand_cost += cp->cand->cost;
5087 iv_ca_set_add_invariants (ivs, cp->cand->depends_on);
5090 ivs->cand_use_cost = add_costs (ivs->cand_use_cost, cp->cost);
5091 iv_ca_set_add_invariants (ivs, cp->depends_on);
5093 if (cp->inv_expr_id != -1)
5095 ivs->used_inv_expr[cp->inv_expr_id]++;
5096 if (ivs->used_inv_expr[cp->inv_expr_id] == 1)
5097 ivs->num_used_inv_expr++;
5099 iv_ca_recount_cost (data, ivs);
5103 /* Extend set IVS by expressing USE by some of the candidates in it
5104 if possible. All important candidates will be considered
5105 if IMPORTANT_CANDIDATES is true. */
5108 iv_ca_add_use (struct ivopts_data *data, struct iv_ca *ivs,
5109 struct iv_use *use, bool important_candidates)
5111 struct cost_pair *best_cp = NULL, *cp;
5116 gcc_assert (ivs->upto >= use->id);
5118 if (ivs->upto == use->id)
5124 cands = (important_candidates ? data->important_candidates : ivs->cands);
5125 EXECUTE_IF_SET_IN_BITMAP (cands, 0, i, bi)
5127 struct iv_cand *cand = iv_cand (data, i);
5129 cp = get_use_iv_cost (data, use, cand);
5131 if (cheaper_cost_pair (cp, best_cp))
5135 iv_ca_set_cp (data, ivs, use, best_cp);
5138 /* Get cost for assignment IVS. */
5141 iv_ca_cost (struct iv_ca *ivs)
5143 /* This was a conditional expression but it triggered a bug in
5146 return infinite_cost;
5151 /* Returns true if all dependences of CP are among invariants in IVS. */
5154 iv_ca_has_deps (struct iv_ca *ivs, struct cost_pair *cp)
5159 if (!cp->depends_on)
5162 EXECUTE_IF_SET_IN_BITMAP (cp->depends_on, 0, i, bi)
5164 if (ivs->n_invariant_uses[i] == 0)
5171 /* Creates change of expressing USE by NEW_CP instead of OLD_CP and chains
5172 it before NEXT_CHANGE. */
5174 static struct iv_ca_delta *
5175 iv_ca_delta_add (struct iv_use *use, struct cost_pair *old_cp,
5176 struct cost_pair *new_cp, struct iv_ca_delta *next_change)
5178 struct iv_ca_delta *change = XNEW (struct iv_ca_delta);
5181 change->old_cp = old_cp;
5182 change->new_cp = new_cp;
5183 change->next_change = next_change;
5188 /* Joins two lists of changes L1 and L2. Destructive -- old lists
5191 static struct iv_ca_delta *
5192 iv_ca_delta_join (struct iv_ca_delta *l1, struct iv_ca_delta *l2)
5194 struct iv_ca_delta *last;
5202 for (last = l1; last->next_change; last = last->next_change)
5204 last->next_change = l2;
5209 /* Reverse the list of changes DELTA, forming the inverse to it. */
5211 static struct iv_ca_delta *
5212 iv_ca_delta_reverse (struct iv_ca_delta *delta)
5214 struct iv_ca_delta *act, *next, *prev = NULL;
5215 struct cost_pair *tmp;
5217 for (act = delta; act; act = next)
5219 next = act->next_change;
5220 act->next_change = prev;
5224 act->old_cp = act->new_cp;
5231 /* Commit changes in DELTA to IVS. If FORWARD is false, the changes are
5232 reverted instead. */
5235 iv_ca_delta_commit (struct ivopts_data *data, struct iv_ca *ivs,
5236 struct iv_ca_delta *delta, bool forward)
5238 struct cost_pair *from, *to;
5239 struct iv_ca_delta *act;
5242 delta = iv_ca_delta_reverse (delta);
5244 for (act = delta; act; act = act->next_change)
5248 gcc_assert (iv_ca_cand_for_use (ivs, act->use) == from);
5249 iv_ca_set_cp (data, ivs, act->use, to);
5253 iv_ca_delta_reverse (delta);
5256 /* Returns true if CAND is used in IVS. */
5259 iv_ca_cand_used_p (struct iv_ca *ivs, struct iv_cand *cand)
5261 return ivs->n_cand_uses[cand->id] > 0;
5264 /* Returns number of induction variable candidates in the set IVS. */
5267 iv_ca_n_cands (struct iv_ca *ivs)
5269 return ivs->n_cands;
5272 /* Free the list of changes DELTA. */
5275 iv_ca_delta_free (struct iv_ca_delta **delta)
5277 struct iv_ca_delta *act, *next;
5279 for (act = *delta; act; act = next)
5281 next = act->next_change;
5288 /* Allocates new iv candidates assignment. */
5290 static struct iv_ca *
5291 iv_ca_new (struct ivopts_data *data)
5293 struct iv_ca *nw = XNEW (struct iv_ca);
5297 nw->cand_for_use = XCNEWVEC (struct cost_pair *, n_iv_uses (data));
5298 nw->n_cand_uses = XCNEWVEC (unsigned, n_iv_cands (data));
5299 nw->cands = BITMAP_ALLOC (NULL);
5302 nw->cand_use_cost = zero_cost;
5304 nw->n_invariant_uses = XCNEWVEC (unsigned, data->max_inv_id + 1);
5305 nw->cost = zero_cost;
5306 nw->used_inv_expr = XCNEWVEC (unsigned, data->inv_expr_id + 1);
5307 nw->num_used_inv_expr = 0;
5312 /* Free memory occupied by the set IVS. */
5315 iv_ca_free (struct iv_ca **ivs)
5317 free ((*ivs)->cand_for_use);
5318 free ((*ivs)->n_cand_uses);
5319 BITMAP_FREE ((*ivs)->cands);
5320 free ((*ivs)->n_invariant_uses);
5321 free ((*ivs)->used_inv_expr);
5326 /* Dumps IVS to FILE. */
5329 iv_ca_dump (struct ivopts_data *data, FILE *file, struct iv_ca *ivs)
5331 const char *pref = " invariants ";
5333 comp_cost cost = iv_ca_cost (ivs);
5335 fprintf (file, " cost: %d (complexity %d)\n", cost.cost, cost.complexity);
5336 fprintf (file, " cand_cost: %d\n cand_use_cost: %d (complexity %d)\n",
5337 ivs->cand_cost, ivs->cand_use_cost.cost, ivs->cand_use_cost.complexity);
5338 bitmap_print (file, ivs->cands, " candidates: ","\n");
5340 for (i = 0; i < ivs->upto; i++)
5342 struct iv_use *use = iv_use (data, i);
5343 struct cost_pair *cp = iv_ca_cand_for_use (ivs, use);
5345 fprintf (file, " use:%d --> iv_cand:%d, cost=(%d,%d)\n",
5346 use->id, cp->cand->id, cp->cost.cost, cp->cost.complexity);
5348 fprintf (file, " use:%d --> ??\n", use->id);
5351 for (i = 1; i <= data->max_inv_id; i++)
5352 if (ivs->n_invariant_uses[i])
5354 fprintf (file, "%s%d", pref, i);
5357 fprintf (file, "\n\n");
5360 /* Try changing candidate in IVS to CAND for each use. Return cost of the
5361 new set, and store differences in DELTA. Number of induction variables
5362 in the new set is stored to N_IVS. MIN_NCAND is a flag. When it is true
5363 the function will try to find a solution with mimimal iv candidates. */
5366 iv_ca_extend (struct ivopts_data *data, struct iv_ca *ivs,
5367 struct iv_cand *cand, struct iv_ca_delta **delta,
5368 unsigned *n_ivs, bool min_ncand)
5373 struct cost_pair *old_cp, *new_cp;
5376 for (i = 0; i < ivs->upto; i++)
5378 use = iv_use (data, i);
5379 old_cp = iv_ca_cand_for_use (ivs, use);
5382 && old_cp->cand == cand)
5385 new_cp = get_use_iv_cost (data, use, cand);
5389 if (!min_ncand && !iv_ca_has_deps (ivs, new_cp))
5392 if (!min_ncand && !cheaper_cost_pair (new_cp, old_cp))
5395 *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta);
5398 iv_ca_delta_commit (data, ivs, *delta, true);
5399 cost = iv_ca_cost (ivs);
5401 *n_ivs = iv_ca_n_cands (ivs);
5402 iv_ca_delta_commit (data, ivs, *delta, false);
5407 /* Try narrowing set IVS by removing CAND. Return the cost of
5408 the new set and store the differences in DELTA. */
5411 iv_ca_narrow (struct ivopts_data *data, struct iv_ca *ivs,
5412 struct iv_cand *cand, struct iv_ca_delta **delta)
5416 struct cost_pair *old_cp, *new_cp, *cp;
5418 struct iv_cand *cnd;
5422 for (i = 0; i < n_iv_uses (data); i++)
5424 use = iv_use (data, i);
5426 old_cp = iv_ca_cand_for_use (ivs, use);
5427 if (old_cp->cand != cand)
5432 if (data->consider_all_candidates)
5434 EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, ci, bi)
5439 cnd = iv_cand (data, ci);
5441 cp = get_use_iv_cost (data, use, cnd);
5445 if (!iv_ca_has_deps (ivs, cp))
5448 if (!cheaper_cost_pair (cp, new_cp))
5456 EXECUTE_IF_AND_IN_BITMAP (use->related_cands, ivs->cands, 0, ci, bi)
5461 cnd = iv_cand (data, ci);
5463 cp = get_use_iv_cost (data, use, cnd);
5466 if (!iv_ca_has_deps (ivs, cp))
5469 if (!cheaper_cost_pair (cp, new_cp))
5478 iv_ca_delta_free (delta);
5479 return infinite_cost;
5482 *delta = iv_ca_delta_add (use, old_cp, new_cp, *delta);
5485 iv_ca_delta_commit (data, ivs, *delta, true);
5486 cost = iv_ca_cost (ivs);
5487 iv_ca_delta_commit (data, ivs, *delta, false);
5492 /* Try optimizing the set of candidates IVS by removing candidates different
5493 from to EXCEPT_CAND from it. Return cost of the new set, and store
5494 differences in DELTA. */
5497 iv_ca_prune (struct ivopts_data *data, struct iv_ca *ivs,
5498 struct iv_cand *except_cand, struct iv_ca_delta **delta)
5501 struct iv_ca_delta *act_delta, *best_delta;
5503 comp_cost best_cost, acost;
5504 struct iv_cand *cand;
5507 best_cost = iv_ca_cost (ivs);
5509 EXECUTE_IF_SET_IN_BITMAP (ivs->cands, 0, i, bi)
5511 cand = iv_cand (data, i);
5513 if (cand == except_cand)
5516 acost = iv_ca_narrow (data, ivs, cand, &act_delta);
5518 if (compare_costs (acost, best_cost) < 0)
5521 iv_ca_delta_free (&best_delta);
5522 best_delta = act_delta;
5525 iv_ca_delta_free (&act_delta);
5534 /* Recurse to possibly remove other unnecessary ivs. */
5535 iv_ca_delta_commit (data, ivs, best_delta, true);
5536 best_cost = iv_ca_prune (data, ivs, except_cand, delta);
5537 iv_ca_delta_commit (data, ivs, best_delta, false);
5538 *delta = iv_ca_delta_join (best_delta, *delta);
5542 /* Tries to extend the sets IVS in the best possible way in order
5543 to express the USE. If ORIGINALP is true, prefer candidates from
5544 the original set of IVs, otherwise favor important candidates not
5545 based on any memory object. */
5548 try_add_cand_for (struct ivopts_data *data, struct iv_ca *ivs,
5549 struct iv_use *use, bool originalp)
5551 comp_cost best_cost, act_cost;
5554 struct iv_cand *cand;
5555 struct iv_ca_delta *best_delta = NULL, *act_delta;
5556 struct cost_pair *cp;
5558 iv_ca_add_use (data, ivs, use, false);
5559 best_cost = iv_ca_cost (ivs);
5561 cp = iv_ca_cand_for_use (ivs, use);
5566 iv_ca_add_use (data, ivs, use, true);
5567 best_cost = iv_ca_cost (ivs);
5568 cp = iv_ca_cand_for_use (ivs, use);
5572 best_delta = iv_ca_delta_add (use, NULL, cp, NULL);
5573 iv_ca_set_no_cp (data, ivs, use);
5576 /* If ORIGINALP is true, try to find the original IV for the use. Otherwise
5577 first try important candidates not based on any memory object. Only if
5578 this fails, try the specific ones. Rationale -- in loops with many
5579 variables the best choice often is to use just one generic biv. If we
5580 added here many ivs specific to the uses, the optimization algorithm later
5581 would be likely to get stuck in a local minimum, thus causing us to create
5582 too many ivs. The approach from few ivs to more seems more likely to be
5583 successful -- starting from few ivs, replacing an expensive use by a
5584 specific iv should always be a win. */
5585 EXECUTE_IF_SET_IN_BITMAP (data->important_candidates, 0, i, bi)
5587 cand = iv_cand (data, i);
5589 if (originalp && cand->pos !=IP_ORIGINAL)
5592 if (!originalp && cand->iv->base_object != NULL_TREE)
5595 if (iv_ca_cand_used_p (ivs, cand))
5598 cp = get_use_iv_cost (data, use, cand);
5602 iv_ca_set_cp (data, ivs, use, cp);
5603 act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL,
5605 iv_ca_set_no_cp (data, ivs, use);
5606 act_delta = iv_ca_delta_add (use, NULL, cp, act_delta);
5608 if (compare_costs (act_cost, best_cost) < 0)
5610 best_cost = act_cost;
5612 iv_ca_delta_free (&best_delta);
5613 best_delta = act_delta;
5616 iv_ca_delta_free (&act_delta);
5619 if (infinite_cost_p (best_cost))
5621 for (i = 0; i < use->n_map_members; i++)
5623 cp = use->cost_map + i;
5628 /* Already tried this. */
5629 if (cand->important)
5631 if (originalp && cand->pos == IP_ORIGINAL)
5633 if (!originalp && cand->iv->base_object == NULL_TREE)
5637 if (iv_ca_cand_used_p (ivs, cand))
5641 iv_ca_set_cp (data, ivs, use, cp);
5642 act_cost = iv_ca_extend (data, ivs, cand, &act_delta, NULL, true);
5643 iv_ca_set_no_cp (data, ivs, use);
5644 act_delta = iv_ca_delta_add (use, iv_ca_cand_for_use (ivs, use),
5647 if (compare_costs (act_cost, best_cost) < 0)
5649 best_cost = act_cost;
5652 iv_ca_delta_free (&best_delta);
5653 best_delta = act_delta;
5656 iv_ca_delta_free (&act_delta);
5660 iv_ca_delta_commit (data, ivs, best_delta, true);
5661 iv_ca_delta_free (&best_delta);
5663 return !infinite_cost_p (best_cost);
5666 /* Finds an initial assignment of candidates to uses. */
5668 static struct iv_ca *
5669 get_initial_solution (struct ivopts_data *data, bool originalp)
5671 struct iv_ca *ivs = iv_ca_new (data);
5674 for (i = 0; i < n_iv_uses (data); i++)
5675 if (!try_add_cand_for (data, ivs, iv_use (data, i), originalp))
5684 /* Tries to improve set of induction variables IVS. */
5687 try_improve_iv_set (struct ivopts_data *data, struct iv_ca *ivs)
5690 comp_cost acost, best_cost = iv_ca_cost (ivs);
5691 struct iv_ca_delta *best_delta = NULL, *act_delta, *tmp_delta;
5692 struct iv_cand *cand;
5694 /* Try extending the set of induction variables by one. */
5695 for (i = 0; i < n_iv_cands (data); i++)
5697 cand = iv_cand (data, i);
5699 if (iv_ca_cand_used_p (ivs, cand))
5702 acost = iv_ca_extend (data, ivs, cand, &act_delta, &n_ivs, false);
5706 /* If we successfully added the candidate and the set is small enough,
5707 try optimizing it by removing other candidates. */
5708 if (n_ivs <= ALWAYS_PRUNE_CAND_SET_BOUND)
5710 iv_ca_delta_commit (data, ivs, act_delta, true);
5711 acost = iv_ca_prune (data, ivs, cand, &tmp_delta);
5712 iv_ca_delta_commit (data, ivs, act_delta, false);
5713 act_delta = iv_ca_delta_join (act_delta, tmp_delta);
5716 if (compare_costs (acost, best_cost) < 0)
5719 iv_ca_delta_free (&best_delta);
5720 best_delta = act_delta;
5723 iv_ca_delta_free (&act_delta);
5728 /* Try removing the candidates from the set instead. */
5729 best_cost = iv_ca_prune (data, ivs, NULL, &best_delta);
5731 /* Nothing more we can do. */
5736 iv_ca_delta_commit (data, ivs, best_delta, true);
5737 gcc_assert (compare_costs (best_cost, iv_ca_cost (ivs)) == 0);
5738 iv_ca_delta_free (&best_delta);
5742 /* Attempts to find the optimal set of induction variables. We do simple
5743 greedy heuristic -- we try to replace at most one candidate in the selected
5744 solution and remove the unused ivs while this improves the cost. */
5746 static struct iv_ca *
5747 find_optimal_iv_set_1 (struct ivopts_data *data, bool originalp)
5751 /* Get the initial solution. */
5752 set = get_initial_solution (data, originalp);
5755 if (dump_file && (dump_flags & TDF_DETAILS))
5756 fprintf (dump_file, "Unable to substitute for ivs, failed.\n");
5760 if (dump_file && (dump_flags & TDF_DETAILS))
5762 fprintf (dump_file, "Initial set of candidates:\n");
5763 iv_ca_dump (data, dump_file, set);
5766 while (try_improve_iv_set (data, set))
5768 if (dump_file && (dump_flags & TDF_DETAILS))
5770 fprintf (dump_file, "Improved to:\n");
5771 iv_ca_dump (data, dump_file, set);
5778 static struct iv_ca *
5779 find_optimal_iv_set (struct ivopts_data *data)
5782 struct iv_ca *set, *origset;
5784 comp_cost cost, origcost;
5786 /* Determine the cost based on a strategy that starts with original IVs,
5787 and try again using a strategy that prefers candidates not based
5789 origset = find_optimal_iv_set_1 (data, true);
5790 set = find_optimal_iv_set_1 (data, false);
5792 if (!origset && !set)
5795 origcost = origset ? iv_ca_cost (origset) : infinite_cost;
5796 cost = set ? iv_ca_cost (set) : infinite_cost;
5798 if (dump_file && (dump_flags & TDF_DETAILS))
5800 fprintf (dump_file, "Original cost %d (complexity %d)\n\n",
5801 origcost.cost, origcost.complexity);
5802 fprintf (dump_file, "Final cost %d (complexity %d)\n\n",
5803 cost.cost, cost.complexity);
5806 /* Choose the one with the best cost. */
5807 if (compare_costs (origcost, cost) <= 0)
5814 iv_ca_free (&origset);
5816 for (i = 0; i < n_iv_uses (data); i++)
5818 use = iv_use (data, i);
5819 use->selected = iv_ca_cand_for_use (set, use)->cand;
5825 /* Creates a new induction variable corresponding to CAND. */
5828 create_new_iv (struct ivopts_data *data, struct iv_cand *cand)
5830 gimple_stmt_iterator incr_pos;
5840 incr_pos = gsi_last_bb (ip_normal_pos (data->current_loop));
5844 incr_pos = gsi_last_bb (ip_end_pos (data->current_loop));
5852 incr_pos = gsi_for_stmt (cand->incremented_at);
5856 /* Mark that the iv is preserved. */
5857 name_info (data, cand->var_before)->preserve_biv = true;
5858 name_info (data, cand->var_after)->preserve_biv = true;
5860 /* Rewrite the increment so that it uses var_before directly. */
5861 find_interesting_uses_op (data, cand->var_after)->selected = cand;
5865 gimple_add_tmp_var (cand->var_before);
5866 add_referenced_var (cand->var_before);
5868 base = unshare_expr (cand->iv->base);
5870 create_iv (base, unshare_expr (cand->iv->step),
5871 cand->var_before, data->current_loop,
5872 &incr_pos, after, &cand->var_before, &cand->var_after);
5875 /* Creates new induction variables described in SET. */
5878 create_new_ivs (struct ivopts_data *data, struct iv_ca *set)
5881 struct iv_cand *cand;
5884 EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi)
5886 cand = iv_cand (data, i);
5887 create_new_iv (data, cand);
5890 if (dump_file && (dump_flags & TDF_DETAILS))
5892 fprintf (dump_file, "\nSelected IV set: \n");
5893 EXECUTE_IF_SET_IN_BITMAP (set->cands, 0, i, bi)
5895 cand = iv_cand (data, i);
5896 dump_cand (dump_file, cand);
5898 fprintf (dump_file, "\n");
5902 /* Rewrites USE (definition of iv used in a nonlinear expression)
5903 using candidate CAND. */
5906 rewrite_use_nonlinear_expr (struct ivopts_data *data,
5907 struct iv_use *use, struct iv_cand *cand)
5912 gimple_stmt_iterator bsi;
5914 /* An important special case -- if we are asked to express value of
5915 the original iv by itself, just exit; there is no need to
5916 introduce a new computation (that might also need casting the
5917 variable to unsigned and back). */
5918 if (cand->pos == IP_ORIGINAL
5919 && cand->incremented_at == use->stmt)
5921 tree step, ctype, utype;
5922 enum tree_code incr_code = PLUS_EXPR, old_code;
5924 gcc_assert (is_gimple_assign (use->stmt));
5925 gcc_assert (gimple_assign_lhs (use->stmt) == cand->var_after);
5927 step = cand->iv->step;
5928 ctype = TREE_TYPE (step);
5929 utype = TREE_TYPE (cand->var_after);
5930 if (TREE_CODE (step) == NEGATE_EXPR)
5932 incr_code = MINUS_EXPR;
5933 step = TREE_OPERAND (step, 0);
5936 /* Check whether we may leave the computation unchanged.
5937 This is the case only if it does not rely on other
5938 computations in the loop -- otherwise, the computation
5939 we rely upon may be removed in remove_unused_ivs,
5940 thus leading to ICE. */
5941 old_code = gimple_assign_rhs_code (use->stmt);
5942 if (old_code == PLUS_EXPR
5943 || old_code == MINUS_EXPR
5944 || old_code == POINTER_PLUS_EXPR)
5946 if (gimple_assign_rhs1 (use->stmt) == cand->var_before)
5947 op = gimple_assign_rhs2 (use->stmt);
5948 else if (old_code != MINUS_EXPR
5949 && gimple_assign_rhs2 (use->stmt) == cand->var_before)
5950 op = gimple_assign_rhs1 (use->stmt);
5958 && (TREE_CODE (op) == INTEGER_CST
5959 || operand_equal_p (op, step, 0)))
5962 /* Otherwise, add the necessary computations to express
5964 op = fold_convert (ctype, cand->var_before);
5965 comp = fold_convert (utype,
5966 build2 (incr_code, ctype, op,
5967 unshare_expr (step)));
5971 comp = get_computation (data->current_loop, use, cand);
5972 gcc_assert (comp != NULL_TREE);
5975 switch (gimple_code (use->stmt))
5978 tgt = PHI_RESULT (use->stmt);
5980 /* If we should keep the biv, do not replace it. */
5981 if (name_info (data, tgt)->preserve_biv)
5984 bsi = gsi_after_labels (gimple_bb (use->stmt));
5988 tgt = gimple_assign_lhs (use->stmt);
5989 bsi = gsi_for_stmt (use->stmt);
5996 if (!valid_gimple_rhs_p (comp)
5997 || (gimple_code (use->stmt) != GIMPLE_PHI
5998 /* We can't allow re-allocating the stmt as it might be pointed
6000 && (get_gimple_rhs_num_ops (TREE_CODE (comp))
6001 >= gimple_num_ops (gsi_stmt (bsi)))))
6003 comp = force_gimple_operand_gsi (&bsi, comp, true, NULL_TREE,
6004 true, GSI_SAME_STMT);
6005 if (POINTER_TYPE_P (TREE_TYPE (tgt)))
6007 duplicate_ssa_name_ptr_info (comp, SSA_NAME_PTR_INFO (tgt));
6008 /* As this isn't a plain copy we have to reset alignment
6010 if (SSA_NAME_PTR_INFO (comp))
6012 SSA_NAME_PTR_INFO (comp)->align = 1;
6013 SSA_NAME_PTR_INFO (comp)->misalign = 0;
6018 if (gimple_code (use->stmt) == GIMPLE_PHI)
6020 ass = gimple_build_assign (tgt, comp);
6021 gsi_insert_before (&bsi, ass, GSI_SAME_STMT);
6023 bsi = gsi_for_stmt (use->stmt);
6024 remove_phi_node (&bsi, false);
6028 gimple_assign_set_rhs_from_tree (&bsi, comp);
6029 use->stmt = gsi_stmt (bsi);
6033 /* Copies the reference information from OLD_REF to NEW_REF. */
6036 copy_ref_info (tree new_ref, tree old_ref)
6038 tree new_ptr_base = NULL_TREE;
6040 TREE_SIDE_EFFECTS (new_ref) = TREE_SIDE_EFFECTS (old_ref);
6041 TREE_THIS_VOLATILE (new_ref) = TREE_THIS_VOLATILE (old_ref);
6043 new_ptr_base = TREE_OPERAND (new_ref, 0);
6045 /* We can transfer points-to information from an old pointer
6046 or decl base to the new one. */
6048 && TREE_CODE (new_ptr_base) == SSA_NAME
6049 && !SSA_NAME_PTR_INFO (new_ptr_base))
6051 tree base = get_base_address (old_ref);
6054 else if ((TREE_CODE (base) == MEM_REF
6055 || TREE_CODE (base) == TARGET_MEM_REF)
6056 && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
6057 && SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)))
6059 struct ptr_info_def *new_pi;
6060 duplicate_ssa_name_ptr_info
6061 (new_ptr_base, SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)));
6062 new_pi = SSA_NAME_PTR_INFO (new_ptr_base);
6063 /* We have to be careful about transfering alignment information. */
6064 if (TREE_CODE (old_ref) == MEM_REF
6065 && !(TREE_CODE (new_ref) == TARGET_MEM_REF
6066 && (TMR_INDEX2 (new_ref)
6067 || (TMR_STEP (new_ref)
6068 && (TREE_INT_CST_LOW (TMR_STEP (new_ref))
6069 < new_pi->align)))))
6071 new_pi->misalign += double_int_sub (mem_ref_offset (old_ref),
6072 mem_ref_offset (new_ref)).low;
6073 new_pi->misalign &= (new_pi->align - 1);
6078 new_pi->misalign = 0;
6081 else if (TREE_CODE (base) == VAR_DECL
6082 || TREE_CODE (base) == PARM_DECL
6083 || TREE_CODE (base) == RESULT_DECL)
6085 struct ptr_info_def *pi = get_ptr_info (new_ptr_base);
6086 pt_solution_set_var (&pi->pt, base);
6091 /* Performs a peephole optimization to reorder the iv update statement with
6092 a mem ref to enable instruction combining in later phases. The mem ref uses
6093 the iv value before the update, so the reordering transformation requires
6094 adjustment of the offset. CAND is the selected IV_CAND.
6098 t = MEM_REF (base, iv1, 8, 16); // base, index, stride, offset
6106 directly propagating t over to (1) will introduce overlapping live range
6107 thus increase register pressure. This peephole transform it into:
6111 t = MEM_REF (base, iv2, 8, 8);
6118 adjust_iv_update_pos (struct iv_cand *cand, struct iv_use *use)
6121 gimple iv_update, stmt;
6123 gimple_stmt_iterator gsi, gsi_iv;
6125 if (cand->pos != IP_NORMAL)
6128 var_after = cand->var_after;
6129 iv_update = SSA_NAME_DEF_STMT (var_after);
6131 bb = gimple_bb (iv_update);
6132 gsi = gsi_last_nondebug_bb (bb);
6133 stmt = gsi_stmt (gsi);
6135 /* Only handle conditional statement for now. */
6136 if (gimple_code (stmt) != GIMPLE_COND)
6139 gsi_prev_nondebug (&gsi);
6140 stmt = gsi_stmt (gsi);
6141 if (stmt != iv_update)
6144 gsi_prev_nondebug (&gsi);
6145 if (gsi_end_p (gsi))
6148 stmt = gsi_stmt (gsi);
6149 if (gimple_code (stmt) != GIMPLE_ASSIGN)
6152 if (stmt != use->stmt)
6155 if (TREE_CODE (gimple_assign_lhs (stmt)) != SSA_NAME)
6158 if (dump_file && (dump_flags & TDF_DETAILS))
6160 fprintf (dump_file, "Reordering \n");
6161 print_gimple_stmt (dump_file, iv_update, 0, 0);
6162 print_gimple_stmt (dump_file, use->stmt, 0, 0);
6163 fprintf (dump_file, "\n");
6166 gsi = gsi_for_stmt (use->stmt);
6167 gsi_iv = gsi_for_stmt (iv_update);
6168 gsi_move_before (&gsi_iv, &gsi);
6170 cand->pos = IP_BEFORE_USE;
6171 cand->incremented_at = use->stmt;
6174 /* Rewrites USE (address that is an iv) using candidate CAND. */
6177 rewrite_use_address (struct ivopts_data *data,
6178 struct iv_use *use, struct iv_cand *cand)
6181 gimple_stmt_iterator bsi = gsi_for_stmt (use->stmt);
6182 tree base_hint = NULL_TREE;
6186 adjust_iv_update_pos (cand, use);
6187 ok = get_computation_aff (data->current_loop, use, cand, use->stmt, &aff);
6189 unshare_aff_combination (&aff);
6191 /* To avoid undefined overflow problems, all IV candidates use unsigned
6192 integer types. The drawback is that this makes it impossible for
6193 create_mem_ref to distinguish an IV that is based on a memory object
6194 from one that represents simply an offset.
6196 To work around this problem, we pass a hint to create_mem_ref that
6197 indicates which variable (if any) in aff is an IV based on a memory
6198 object. Note that we only consider the candidate. If this is not
6199 based on an object, the base of the reference is in some subexpression
6200 of the use -- but these will use pointer types, so they are recognized
6201 by the create_mem_ref heuristics anyway. */
6202 if (cand->iv->base_object)
6203 base_hint = var_at_stmt (data->current_loop, cand, use->stmt);
6205 iv = var_at_stmt (data->current_loop, cand, use->stmt);
6206 ref = create_mem_ref (&bsi, TREE_TYPE (*use->op_p), &aff,
6207 reference_alias_ptr_type (*use->op_p),
6208 iv, base_hint, data->speed);
6209 copy_ref_info (ref, *use->op_p);
6213 /* Rewrites USE (the condition such that one of the arguments is an iv) using
6217 rewrite_use_compare (struct ivopts_data *data,
6218 struct iv_use *use, struct iv_cand *cand)
6220 tree comp, *var_p, op, bound;
6221 gimple_stmt_iterator bsi = gsi_for_stmt (use->stmt);
6222 enum tree_code compare;
6223 struct cost_pair *cp = get_use_iv_cost (data, use, cand);
6229 tree var = var_at_stmt (data->current_loop, cand, use->stmt);
6230 tree var_type = TREE_TYPE (var);
6233 if (dump_file && (dump_flags & TDF_DETAILS))
6235 fprintf (dump_file, "Replacing exit test: ");
6236 print_gimple_stmt (dump_file, use->stmt, 0, TDF_SLIM);
6238 compare = iv_elimination_compare (data, use);
6239 bound = unshare_expr (fold_convert (var_type, bound));
6240 op = force_gimple_operand (bound, &stmts, true, NULL_TREE);
6242 gsi_insert_seq_on_edge_immediate (
6243 loop_preheader_edge (data->current_loop),
6246 gimple_cond_set_lhs (use->stmt, var);
6247 gimple_cond_set_code (use->stmt, compare);
6248 gimple_cond_set_rhs (use->stmt, op);
6252 /* The induction variable elimination failed; just express the original
6254 comp = get_computation (data->current_loop, use, cand);
6255 gcc_assert (comp != NULL_TREE);
6257 ok = extract_cond_operands (data, use->stmt, &var_p, NULL, NULL, NULL);
6260 *var_p = force_gimple_operand_gsi (&bsi, comp, true, SSA_NAME_VAR (*var_p),
6261 true, GSI_SAME_STMT);
6264 /* Rewrites USE using candidate CAND. */
6267 rewrite_use (struct ivopts_data *data, struct iv_use *use, struct iv_cand *cand)
6271 case USE_NONLINEAR_EXPR:
6272 rewrite_use_nonlinear_expr (data, use, cand);
6276 rewrite_use_address (data, use, cand);
6280 rewrite_use_compare (data, use, cand);
6287 update_stmt (use->stmt);
6290 /* Rewrite the uses using the selected induction variables. */
6293 rewrite_uses (struct ivopts_data *data)
6296 struct iv_cand *cand;
6299 for (i = 0; i < n_iv_uses (data); i++)
6301 use = iv_use (data, i);
6302 cand = use->selected;
6305 rewrite_use (data, use, cand);
6309 /* Removes the ivs that are not used after rewriting. */
6312 remove_unused_ivs (struct ivopts_data *data)
6316 bitmap toremove = BITMAP_ALLOC (NULL);
6318 /* Figure out an order in which to release SSA DEFs so that we don't
6319 release something that we'd have to propagate into a debug stmt
6321 EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, j, bi)
6323 struct version_info *info;
6325 info = ver_info (data, j);
6327 && !integer_zerop (info->iv->step)
6329 && !info->iv->have_use_for
6330 && !info->preserve_biv)
6331 bitmap_set_bit (toremove, SSA_NAME_VERSION (info->iv->ssa_name));
6334 release_defs_bitset (toremove);
6336 BITMAP_FREE (toremove);
6339 /* Frees memory occupied by struct tree_niter_desc in *VALUE. Callback
6340 for pointer_map_traverse. */
6343 free_tree_niter_desc (const void *key ATTRIBUTE_UNUSED, void **value,
6344 void *data ATTRIBUTE_UNUSED)
6346 struct tree_niter_desc *const niter = (struct tree_niter_desc *) *value;
6352 /* Frees data allocated by the optimization of a single loop. */
6355 free_loop_data (struct ivopts_data *data)
6363 pointer_map_traverse (data->niters, free_tree_niter_desc, NULL);
6364 pointer_map_destroy (data->niters);
6365 data->niters = NULL;
6368 EXECUTE_IF_SET_IN_BITMAP (data->relevant, 0, i, bi)
6370 struct version_info *info;
6372 info = ver_info (data, i);
6375 info->has_nonlin_use = false;
6376 info->preserve_biv = false;
6379 bitmap_clear (data->relevant);
6380 bitmap_clear (data->important_candidates);
6382 for (i = 0; i < n_iv_uses (data); i++)
6384 struct iv_use *use = iv_use (data, i);
6387 BITMAP_FREE (use->related_cands);
6388 for (j = 0; j < use->n_map_members; j++)
6389 if (use->cost_map[j].depends_on)
6390 BITMAP_FREE (use->cost_map[j].depends_on);
6391 free (use->cost_map);
6394 VEC_truncate (iv_use_p, data->iv_uses, 0);
6396 for (i = 0; i < n_iv_cands (data); i++)
6398 struct iv_cand *cand = iv_cand (data, i);
6401 if (cand->depends_on)
6402 BITMAP_FREE (cand->depends_on);
6405 VEC_truncate (iv_cand_p, data->iv_candidates, 0);
6407 if (data->version_info_size < num_ssa_names)
6409 data->version_info_size = 2 * num_ssa_names;
6410 free (data->version_info);
6411 data->version_info = XCNEWVEC (struct version_info, data->version_info_size);
6414 data->max_inv_id = 0;
6416 FOR_EACH_VEC_ELT (tree, decl_rtl_to_reset, i, obj)
6417 SET_DECL_RTL (obj, NULL_RTX);
6419 VEC_truncate (tree, decl_rtl_to_reset, 0);
6421 htab_empty (data->inv_expr_tab);
6422 data->inv_expr_id = 0;
6425 /* Finalizes data structures used by the iv optimization pass. LOOPS is the
6429 tree_ssa_iv_optimize_finalize (struct ivopts_data *data)
6431 free_loop_data (data);
6432 free (data->version_info);
6433 BITMAP_FREE (data->relevant);
6434 BITMAP_FREE (data->important_candidates);
6436 VEC_free (tree, heap, decl_rtl_to_reset);
6437 VEC_free (iv_use_p, heap, data->iv_uses);
6438 VEC_free (iv_cand_p, heap, data->iv_candidates);
6439 htab_delete (data->inv_expr_tab);
6442 /* Returns true if the loop body BODY includes any function calls. */
6445 loop_body_includes_call (basic_block *body, unsigned num_nodes)
6447 gimple_stmt_iterator gsi;
6450 for (i = 0; i < num_nodes; i++)
6451 for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi))
6453 gimple stmt = gsi_stmt (gsi);
6454 if (is_gimple_call (stmt)
6455 && !is_inexpensive_builtin (gimple_call_fndecl (stmt)))
6461 /* Optimizes the LOOP. Returns true if anything changed. */
6464 tree_ssa_iv_optimize_loop (struct ivopts_data *data, struct loop *loop)
6466 bool changed = false;
6467 struct iv_ca *iv_ca;
6471 gcc_assert (!data->niters);
6472 data->current_loop = loop;
6473 data->speed = optimize_loop_for_speed_p (loop);
6475 if (dump_file && (dump_flags & TDF_DETAILS))
6477 fprintf (dump_file, "Processing loop %d\n", loop->num);
6479 exit = single_dom_exit (loop);
6482 fprintf (dump_file, " single exit %d -> %d, exit condition ",
6483 exit->src->index, exit->dest->index);
6484 print_gimple_stmt (dump_file, last_stmt (exit->src), 0, TDF_SLIM);
6485 fprintf (dump_file, "\n");
6488 fprintf (dump_file, "\n");
6491 body = get_loop_body (loop);
6492 data->body_includes_call = loop_body_includes_call (body, loop->num_nodes);
6493 renumber_gimple_stmt_uids_in_blocks (body, loop->num_nodes);
6496 /* For each ssa name determines whether it behaves as an induction variable
6498 if (!find_induction_variables (data))
6501 /* Finds interesting uses (item 1). */
6502 find_interesting_uses (data);
6503 if (n_iv_uses (data) > MAX_CONSIDERED_USES)
6506 /* Finds candidates for the induction variables (item 2). */
6507 find_iv_candidates (data);
6509 /* Calculates the costs (item 3, part 1). */
6510 determine_iv_costs (data);
6511 determine_use_iv_costs (data);
6512 determine_set_costs (data);
6514 /* Find the optimal set of induction variables (item 3, part 2). */
6515 iv_ca = find_optimal_iv_set (data);
6520 /* Create the new induction variables (item 4, part 1). */
6521 create_new_ivs (data, iv_ca);
6522 iv_ca_free (&iv_ca);
6524 /* Rewrite the uses (item 4, part 2). */
6525 rewrite_uses (data);
6527 /* Remove the ivs that are unused after rewriting. */
6528 remove_unused_ivs (data);
6530 /* We have changed the structure of induction variables; it might happen
6531 that definitions in the scev database refer to some of them that were
6536 free_loop_data (data);
6541 /* Main entry point. Optimizes induction variables in loops. */
6544 tree_ssa_iv_optimize (void)
6547 struct ivopts_data data;
6550 tree_ssa_iv_optimize_init (&data);
6552 /* Optimize the loops starting with the innermost ones. */
6553 FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST)
6555 if (dump_file && (dump_flags & TDF_DETAILS))
6556 flow_loop_dump (loop, dump_file, NULL, 1);
6558 tree_ssa_iv_optimize_loop (&data, loop);
6561 tree_ssa_iv_optimize_finalize (&data);