1 /* Global, SSA-based optimizations using mathematical identities.
2 Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
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 /* Currently, the only mini-pass in this file tries to CSE reciprocal
22 operations. These are common in sequences such as this one:
24 modulus = sqrt(x*x + y*y + z*z);
29 that can be optimized to
31 modulus = sqrt(x*x + y*y + z*z);
32 rmodulus = 1.0 / modulus;
37 We do this for loop invariant divisors, and with this pass whenever
38 we notice that a division has the same divisor multiple times.
40 Of course, like in PRE, we don't insert a division if a dominator
41 already has one. However, this cannot be done as an extension of
42 PRE for several reasons.
44 First of all, with some experiments it was found out that the
45 transformation is not always useful if there are only two divisions
46 hy the same divisor. This is probably because modern processors
47 can pipeline the divisions; on older, in-order processors it should
48 still be effective to optimize two divisions by the same number.
49 We make this a param, and it shall be called N in the remainder of
52 Second, if trapping math is active, we have less freedom on where
53 to insert divisions: we can only do so in basic blocks that already
54 contain one. (If divisions don't trap, instead, we can insert
55 divisions elsewhere, which will be in blocks that are common dominators
56 of those that have the division).
58 We really don't want to compute the reciprocal unless a division will
59 be found. To do this, we won't insert the division in a basic block
60 that has less than N divisions *post-dominating* it.
62 The algorithm constructs a subset of the dominator tree, holding the
63 blocks containing the divisions and the common dominators to them,
64 and walk it twice. The first walk is in post-order, and it annotates
65 each block with the number of divisions that post-dominate it: this
66 gives information on where divisions can be inserted profitably.
67 The second walk is in pre-order, and it inserts divisions as explained
68 above, and replaces divisions by multiplications.
70 In the best case, the cost of the pass is O(n_statements). In the
71 worst-case, the cost is due to creating the dominator tree subset,
72 with a cost of O(n_basic_blocks ^ 2); however this can only happen
73 for n_statements / n_basic_blocks statements. So, the amortized cost
74 of creating the dominator tree subset is O(n_basic_blocks) and the
75 worst-case cost of the pass is O(n_statements * n_basic_blocks).
77 More practically, the cost will be small because there are few
78 divisions, and they tend to be in the same basic block, so insert_bb
79 is called very few times.
81 If we did this using domwalk.c, an efficient implementation would have
82 to work on all the variables in a single pass, because we could not
83 work on just a subset of the dominator tree, as we do now, and the
84 cost would also be something like O(n_statements * n_basic_blocks).
85 The data structures would be more complex in order to work on all the
86 variables in a single pass. */
90 #include "coretypes.h"
94 #include "tree-flow.h"
96 #include "tree-pass.h"
97 #include "alloc-pool.h"
98 #include "basic-block.h"
100 #include "gimple-pretty-print.h"
102 /* FIXME: RTL headers have to be included here for optabs. */
103 #include "rtl.h" /* Because optabs.h wants enum rtx_code. */
104 #include "expr.h" /* Because optabs.h wants sepops. */
107 /* This structure represents one basic block that either computes a
108 division, or is a common dominator for basic block that compute a
111 /* The basic block represented by this structure. */
114 /* If non-NULL, the SSA_NAME holding the definition for a reciprocal
118 /* If non-NULL, the GIMPLE_ASSIGN for a reciprocal computation that
119 was inserted in BB. */
120 gimple recip_def_stmt;
122 /* Pointer to a list of "struct occurrence"s for blocks dominated
124 struct occurrence *children;
126 /* Pointer to the next "struct occurrence"s in the list of blocks
127 sharing a common dominator. */
128 struct occurrence *next;
130 /* The number of divisions that are in BB before compute_merit. The
131 number of divisions that are in BB or post-dominate it after
135 /* True if the basic block has a division, false if it is a common
136 dominator for basic blocks that do. If it is false and trapping
137 math is active, BB is not a candidate for inserting a reciprocal. */
138 bool bb_has_division;
143 /* Number of 1.0/X ops inserted. */
146 /* Number of 1.0/FUNC ops inserted. */
152 /* Number of cexpi calls inserted. */
158 /* Number of hand-written 32-bit bswaps found. */
161 /* Number of hand-written 64-bit bswaps found. */
167 /* Number of widening multiplication ops inserted. */
168 int widen_mults_inserted;
170 /* Number of integer multiply-and-accumulate ops inserted. */
173 /* Number of fp fused multiply-add ops inserted. */
177 /* The instance of "struct occurrence" representing the highest
178 interesting block in the dominator tree. */
179 static struct occurrence *occ_head;
181 /* Allocation pool for getting instances of "struct occurrence". */
182 static alloc_pool occ_pool;
186 /* Allocate and return a new struct occurrence for basic block BB, and
187 whose children list is headed by CHILDREN. */
188 static struct occurrence *
189 occ_new (basic_block bb, struct occurrence *children)
191 struct occurrence *occ;
193 bb->aux = occ = (struct occurrence *) pool_alloc (occ_pool);
194 memset (occ, 0, sizeof (struct occurrence));
197 occ->children = children;
202 /* Insert NEW_OCC into our subset of the dominator tree. P_HEAD points to a
203 list of "struct occurrence"s, one per basic block, having IDOM as
204 their common dominator.
206 We try to insert NEW_OCC as deep as possible in the tree, and we also
207 insert any other block that is a common dominator for BB and one
208 block already in the tree. */
211 insert_bb (struct occurrence *new_occ, basic_block idom,
212 struct occurrence **p_head)
214 struct occurrence *occ, **p_occ;
216 for (p_occ = p_head; (occ = *p_occ) != NULL; )
218 basic_block bb = new_occ->bb, occ_bb = occ->bb;
219 basic_block dom = nearest_common_dominator (CDI_DOMINATORS, occ_bb, bb);
222 /* BB dominates OCC_BB. OCC becomes NEW_OCC's child: remove OCC
225 occ->next = new_occ->children;
226 new_occ->children = occ;
228 /* Try the next block (it may as well be dominated by BB). */
231 else if (dom == occ_bb)
233 /* OCC_BB dominates BB. Tail recurse to look deeper. */
234 insert_bb (new_occ, dom, &occ->children);
238 else if (dom != idom)
240 gcc_assert (!dom->aux);
242 /* There is a dominator between IDOM and BB, add it and make
243 two children out of NEW_OCC and OCC. First, remove OCC from
249 /* None of the previous blocks has DOM as a dominator: if we tail
250 recursed, we would reexamine them uselessly. Just switch BB with
251 DOM, and go on looking for blocks dominated by DOM. */
252 new_occ = occ_new (dom, new_occ);
257 /* Nothing special, go on with the next element. */
262 /* No place was found as a child of IDOM. Make BB a sibling of IDOM. */
263 new_occ->next = *p_head;
267 /* Register that we found a division in BB. */
270 register_division_in (basic_block bb)
272 struct occurrence *occ;
274 occ = (struct occurrence *) bb->aux;
277 occ = occ_new (bb, NULL);
278 insert_bb (occ, ENTRY_BLOCK_PTR, &occ_head);
281 occ->bb_has_division = true;
282 occ->num_divisions++;
286 /* Compute the number of divisions that postdominate each block in OCC and
290 compute_merit (struct occurrence *occ)
292 struct occurrence *occ_child;
293 basic_block dom = occ->bb;
295 for (occ_child = occ->children; occ_child; occ_child = occ_child->next)
298 if (occ_child->children)
299 compute_merit (occ_child);
302 bb = single_noncomplex_succ (dom);
306 if (dominated_by_p (CDI_POST_DOMINATORS, bb, occ_child->bb))
307 occ->num_divisions += occ_child->num_divisions;
312 /* Return whether USE_STMT is a floating-point division by DEF. */
314 is_division_by (gimple use_stmt, tree def)
316 return is_gimple_assign (use_stmt)
317 && gimple_assign_rhs_code (use_stmt) == RDIV_EXPR
318 && gimple_assign_rhs2 (use_stmt) == def
319 /* Do not recognize x / x as valid division, as we are getting
320 confused later by replacing all immediate uses x in such
322 && gimple_assign_rhs1 (use_stmt) != def;
325 /* Walk the subset of the dominator tree rooted at OCC, setting the
326 RECIP_DEF field to a definition of 1.0 / DEF that can be used in
327 the given basic block. The field may be left NULL, of course,
328 if it is not possible or profitable to do the optimization.
330 DEF_BSI is an iterator pointing at the statement defining DEF.
331 If RECIP_DEF is set, a dominator already has a computation that can
335 insert_reciprocals (gimple_stmt_iterator *def_gsi, struct occurrence *occ,
336 tree def, tree recip_def, int threshold)
340 gimple_stmt_iterator gsi;
341 struct occurrence *occ_child;
344 && (occ->bb_has_division || !flag_trapping_math)
345 && occ->num_divisions >= threshold)
347 /* Make a variable with the replacement and substitute it. */
348 type = TREE_TYPE (def);
349 recip_def = make_rename_temp (type, "reciptmp");
350 new_stmt = gimple_build_assign_with_ops (RDIV_EXPR, recip_def,
351 build_one_cst (type), def);
353 if (occ->bb_has_division)
355 /* Case 1: insert before an existing division. */
356 gsi = gsi_after_labels (occ->bb);
357 while (!gsi_end_p (gsi) && !is_division_by (gsi_stmt (gsi), def))
360 gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
362 else if (def_gsi && occ->bb == def_gsi->bb)
364 /* Case 2: insert right after the definition. Note that this will
365 never happen if the definition statement can throw, because in
366 that case the sole successor of the statement's basic block will
367 dominate all the uses as well. */
368 gsi_insert_after (def_gsi, new_stmt, GSI_NEW_STMT);
372 /* Case 3: insert in a basic block not containing defs/uses. */
373 gsi = gsi_after_labels (occ->bb);
374 gsi_insert_before (&gsi, new_stmt, GSI_SAME_STMT);
377 reciprocal_stats.rdivs_inserted++;
379 occ->recip_def_stmt = new_stmt;
382 occ->recip_def = recip_def;
383 for (occ_child = occ->children; occ_child; occ_child = occ_child->next)
384 insert_reciprocals (def_gsi, occ_child, def, recip_def, threshold);
388 /* Replace the division at USE_P with a multiplication by the reciprocal, if
392 replace_reciprocal (use_operand_p use_p)
394 gimple use_stmt = USE_STMT (use_p);
395 basic_block bb = gimple_bb (use_stmt);
396 struct occurrence *occ = (struct occurrence *) bb->aux;
398 if (optimize_bb_for_speed_p (bb)
399 && occ->recip_def && use_stmt != occ->recip_def_stmt)
401 gimple_assign_set_rhs_code (use_stmt, MULT_EXPR);
402 SET_USE (use_p, occ->recip_def);
403 fold_stmt_inplace (use_stmt);
404 update_stmt (use_stmt);
409 /* Free OCC and return one more "struct occurrence" to be freed. */
411 static struct occurrence *
412 free_bb (struct occurrence *occ)
414 struct occurrence *child, *next;
416 /* First get the two pointers hanging off OCC. */
418 child = occ->children;
420 pool_free (occ_pool, occ);
422 /* Now ensure that we don't recurse unless it is necessary. */
428 next = free_bb (next);
435 /* Look for floating-point divisions among DEF's uses, and try to
436 replace them by multiplications with the reciprocal. Add
437 as many statements computing the reciprocal as needed.
439 DEF must be a GIMPLE register of a floating-point type. */
442 execute_cse_reciprocals_1 (gimple_stmt_iterator *def_gsi, tree def)
445 imm_use_iterator use_iter;
446 struct occurrence *occ;
447 int count = 0, threshold;
449 gcc_assert (FLOAT_TYPE_P (TREE_TYPE (def)) && is_gimple_reg (def));
451 FOR_EACH_IMM_USE_FAST (use_p, use_iter, def)
453 gimple use_stmt = USE_STMT (use_p);
454 if (is_division_by (use_stmt, def))
456 register_division_in (gimple_bb (use_stmt));
461 /* Do the expensive part only if we can hope to optimize something. */
462 threshold = targetm.min_divisions_for_recip_mul (TYPE_MODE (TREE_TYPE (def)));
463 if (count >= threshold)
466 for (occ = occ_head; occ; occ = occ->next)
469 insert_reciprocals (def_gsi, occ, def, NULL, threshold);
472 FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, def)
474 if (is_division_by (use_stmt, def))
476 FOR_EACH_IMM_USE_ON_STMT (use_p, use_iter)
477 replace_reciprocal (use_p);
482 for (occ = occ_head; occ; )
489 gate_cse_reciprocals (void)
491 return optimize && flag_reciprocal_math;
494 /* Go through all the floating-point SSA_NAMEs, and call
495 execute_cse_reciprocals_1 on each of them. */
497 execute_cse_reciprocals (void)
502 occ_pool = create_alloc_pool ("dominators for recip",
503 sizeof (struct occurrence),
504 n_basic_blocks / 3 + 1);
506 memset (&reciprocal_stats, 0, sizeof (reciprocal_stats));
507 calculate_dominance_info (CDI_DOMINATORS);
508 calculate_dominance_info (CDI_POST_DOMINATORS);
510 #ifdef ENABLE_CHECKING
512 gcc_assert (!bb->aux);
515 for (arg = DECL_ARGUMENTS (cfun->decl); arg; arg = DECL_CHAIN (arg))
516 if (gimple_default_def (cfun, arg)
517 && FLOAT_TYPE_P (TREE_TYPE (arg))
518 && is_gimple_reg (arg))
519 execute_cse_reciprocals_1 (NULL, gimple_default_def (cfun, arg));
523 gimple_stmt_iterator gsi;
527 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi))
529 phi = gsi_stmt (gsi);
530 def = PHI_RESULT (phi);
531 if (FLOAT_TYPE_P (TREE_TYPE (def))
532 && is_gimple_reg (def))
533 execute_cse_reciprocals_1 (NULL, def);
536 for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
538 gimple stmt = gsi_stmt (gsi);
540 if (gimple_has_lhs (stmt)
541 && (def = SINGLE_SSA_TREE_OPERAND (stmt, SSA_OP_DEF)) != NULL
542 && FLOAT_TYPE_P (TREE_TYPE (def))
543 && TREE_CODE (def) == SSA_NAME)
544 execute_cse_reciprocals_1 (&gsi, def);
547 if (optimize_bb_for_size_p (bb))
550 /* Scan for a/func(b) and convert it to reciprocal a*rfunc(b). */
551 for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
553 gimple stmt = gsi_stmt (gsi);
556 if (is_gimple_assign (stmt)
557 && gimple_assign_rhs_code (stmt) == RDIV_EXPR)
559 tree arg1 = gimple_assign_rhs2 (stmt);
562 if (TREE_CODE (arg1) != SSA_NAME)
565 stmt1 = SSA_NAME_DEF_STMT (arg1);
567 if (is_gimple_call (stmt1)
568 && gimple_call_lhs (stmt1)
569 && (fndecl = gimple_call_fndecl (stmt1))
570 && (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
571 || DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD))
573 enum built_in_function code;
578 code = DECL_FUNCTION_CODE (fndecl);
579 md_code = DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD;
581 fndecl = targetm.builtin_reciprocal (code, md_code, false);
585 /* Check that all uses of the SSA name are divisions,
586 otherwise replacing the defining statement will do
589 FOR_EACH_IMM_USE_FAST (use_p, ui, arg1)
591 gimple stmt2 = USE_STMT (use_p);
592 if (is_gimple_debug (stmt2))
594 if (!is_gimple_assign (stmt2)
595 || gimple_assign_rhs_code (stmt2) != RDIV_EXPR
596 || gimple_assign_rhs1 (stmt2) == arg1
597 || gimple_assign_rhs2 (stmt2) != arg1)
606 gimple_replace_lhs (stmt1, arg1);
607 gimple_call_set_fndecl (stmt1, fndecl);
609 reciprocal_stats.rfuncs_inserted++;
611 FOR_EACH_IMM_USE_STMT (stmt, ui, arg1)
613 gimple_assign_set_rhs_code (stmt, MULT_EXPR);
614 fold_stmt_inplace (stmt);
622 statistics_counter_event (cfun, "reciprocal divs inserted",
623 reciprocal_stats.rdivs_inserted);
624 statistics_counter_event (cfun, "reciprocal functions inserted",
625 reciprocal_stats.rfuncs_inserted);
627 free_dominance_info (CDI_DOMINATORS);
628 free_dominance_info (CDI_POST_DOMINATORS);
629 free_alloc_pool (occ_pool);
633 struct gimple_opt_pass pass_cse_reciprocals =
638 gate_cse_reciprocals, /* gate */
639 execute_cse_reciprocals, /* execute */
642 0, /* static_pass_number */
644 PROP_ssa, /* properties_required */
645 0, /* properties_provided */
646 0, /* properties_destroyed */
647 0, /* todo_flags_start */
648 TODO_dump_func | TODO_update_ssa | TODO_verify_ssa
649 | TODO_verify_stmts /* todo_flags_finish */
653 /* Records an occurrence at statement USE_STMT in the vector of trees
654 STMTS if it is dominated by *TOP_BB or dominates it or this basic block
655 is not yet initialized. Returns true if the occurrence was pushed on
656 the vector. Adjusts *TOP_BB to be the basic block dominating all
657 statements in the vector. */
660 maybe_record_sincos (VEC(gimple, heap) **stmts,
661 basic_block *top_bb, gimple use_stmt)
663 basic_block use_bb = gimple_bb (use_stmt);
665 && (*top_bb == use_bb
666 || dominated_by_p (CDI_DOMINATORS, use_bb, *top_bb)))
667 VEC_safe_push (gimple, heap, *stmts, use_stmt);
669 || dominated_by_p (CDI_DOMINATORS, *top_bb, use_bb))
671 VEC_safe_push (gimple, heap, *stmts, use_stmt);
680 /* Look for sin, cos and cexpi calls with the same argument NAME and
681 create a single call to cexpi CSEing the result in this case.
682 We first walk over all immediate uses of the argument collecting
683 statements that we can CSE in a vector and in a second pass replace
684 the statement rhs with a REALPART or IMAGPART expression on the
685 result of the cexpi call we insert before the use statement that
686 dominates all other candidates. */
689 execute_cse_sincos_1 (tree name)
691 gimple_stmt_iterator gsi;
692 imm_use_iterator use_iter;
693 tree fndecl, res, type;
694 gimple def_stmt, use_stmt, stmt;
695 int seen_cos = 0, seen_sin = 0, seen_cexpi = 0;
696 VEC(gimple, heap) *stmts = NULL;
697 basic_block top_bb = NULL;
699 bool cfg_changed = false;
701 type = TREE_TYPE (name);
702 FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, name)
704 if (gimple_code (use_stmt) != GIMPLE_CALL
705 || !gimple_call_lhs (use_stmt)
706 || !(fndecl = gimple_call_fndecl (use_stmt))
707 || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
710 switch (DECL_FUNCTION_CODE (fndecl))
712 CASE_FLT_FN (BUILT_IN_COS):
713 seen_cos |= maybe_record_sincos (&stmts, &top_bb, use_stmt) ? 1 : 0;
716 CASE_FLT_FN (BUILT_IN_SIN):
717 seen_sin |= maybe_record_sincos (&stmts, &top_bb, use_stmt) ? 1 : 0;
720 CASE_FLT_FN (BUILT_IN_CEXPI):
721 seen_cexpi |= maybe_record_sincos (&stmts, &top_bb, use_stmt) ? 1 : 0;
728 if (seen_cos + seen_sin + seen_cexpi <= 1)
730 VEC_free(gimple, heap, stmts);
734 /* Simply insert cexpi at the beginning of top_bb but not earlier than
735 the name def statement. */
736 fndecl = mathfn_built_in (type, BUILT_IN_CEXPI);
739 res = create_tmp_reg (TREE_TYPE (TREE_TYPE (fndecl)), "sincostmp");
740 stmt = gimple_build_call (fndecl, 1, name);
741 res = make_ssa_name (res, stmt);
742 gimple_call_set_lhs (stmt, res);
744 def_stmt = SSA_NAME_DEF_STMT (name);
745 if (!SSA_NAME_IS_DEFAULT_DEF (name)
746 && gimple_code (def_stmt) != GIMPLE_PHI
747 && gimple_bb (def_stmt) == top_bb)
749 gsi = gsi_for_stmt (def_stmt);
750 gsi_insert_after (&gsi, stmt, GSI_SAME_STMT);
754 gsi = gsi_after_labels (top_bb);
755 gsi_insert_before (&gsi, stmt, GSI_SAME_STMT);
758 sincos_stats.inserted++;
760 /* And adjust the recorded old call sites. */
761 for (i = 0; VEC_iterate(gimple, stmts, i, use_stmt); ++i)
764 fndecl = gimple_call_fndecl (use_stmt);
766 switch (DECL_FUNCTION_CODE (fndecl))
768 CASE_FLT_FN (BUILT_IN_COS):
769 rhs = fold_build1 (REALPART_EXPR, type, res);
772 CASE_FLT_FN (BUILT_IN_SIN):
773 rhs = fold_build1 (IMAGPART_EXPR, type, res);
776 CASE_FLT_FN (BUILT_IN_CEXPI):
784 /* Replace call with a copy. */
785 stmt = gimple_build_assign (gimple_call_lhs (use_stmt), rhs);
787 gsi = gsi_for_stmt (use_stmt);
788 gsi_replace (&gsi, stmt, true);
789 if (gimple_purge_dead_eh_edges (gimple_bb (stmt)))
793 VEC_free(gimple, heap, stmts);
798 /* To evaluate powi(x,n), the floating point value x raised to the
799 constant integer exponent n, we use a hybrid algorithm that
800 combines the "window method" with look-up tables. For an
801 introduction to exponentiation algorithms and "addition chains",
802 see section 4.6.3, "Evaluation of Powers" of Donald E. Knuth,
803 "Seminumerical Algorithms", Vol. 2, "The Art of Computer Programming",
804 3rd Edition, 1998, and Daniel M. Gordon, "A Survey of Fast Exponentiation
805 Methods", Journal of Algorithms, Vol. 27, pp. 129-146, 1998. */
807 /* Provide a default value for POWI_MAX_MULTS, the maximum number of
808 multiplications to inline before calling the system library's pow
809 function. powi(x,n) requires at worst 2*bits(n)-2 multiplications,
810 so this default never requires calling pow, powf or powl. */
812 #ifndef POWI_MAX_MULTS
813 #define POWI_MAX_MULTS (2*HOST_BITS_PER_WIDE_INT-2)
816 /* The size of the "optimal power tree" lookup table. All
817 exponents less than this value are simply looked up in the
818 powi_table below. This threshold is also used to size the
819 cache of pseudo registers that hold intermediate results. */
820 #define POWI_TABLE_SIZE 256
822 /* The size, in bits of the window, used in the "window method"
823 exponentiation algorithm. This is equivalent to a radix of
824 (1<<POWI_WINDOW_SIZE) in the corresponding "m-ary method". */
825 #define POWI_WINDOW_SIZE 3
827 /* The following table is an efficient representation of an
828 "optimal power tree". For each value, i, the corresponding
829 value, j, in the table states than an optimal evaluation
830 sequence for calculating pow(x,i) can be found by evaluating
831 pow(x,j)*pow(x,i-j). An optimal power tree for the first
832 100 integers is given in Knuth's "Seminumerical algorithms". */
834 static const unsigned char powi_table[POWI_TABLE_SIZE] =
836 0, 1, 1, 2, 2, 3, 3, 4, /* 0 - 7 */
837 4, 6, 5, 6, 6, 10, 7, 9, /* 8 - 15 */
838 8, 16, 9, 16, 10, 12, 11, 13, /* 16 - 23 */
839 12, 17, 13, 18, 14, 24, 15, 26, /* 24 - 31 */
840 16, 17, 17, 19, 18, 33, 19, 26, /* 32 - 39 */
841 20, 25, 21, 40, 22, 27, 23, 44, /* 40 - 47 */
842 24, 32, 25, 34, 26, 29, 27, 44, /* 48 - 55 */
843 28, 31, 29, 34, 30, 60, 31, 36, /* 56 - 63 */
844 32, 64, 33, 34, 34, 46, 35, 37, /* 64 - 71 */
845 36, 65, 37, 50, 38, 48, 39, 69, /* 72 - 79 */
846 40, 49, 41, 43, 42, 51, 43, 58, /* 80 - 87 */
847 44, 64, 45, 47, 46, 59, 47, 76, /* 88 - 95 */
848 48, 65, 49, 66, 50, 67, 51, 66, /* 96 - 103 */
849 52, 70, 53, 74, 54, 104, 55, 74, /* 104 - 111 */
850 56, 64, 57, 69, 58, 78, 59, 68, /* 112 - 119 */
851 60, 61, 61, 80, 62, 75, 63, 68, /* 120 - 127 */
852 64, 65, 65, 128, 66, 129, 67, 90, /* 128 - 135 */
853 68, 73, 69, 131, 70, 94, 71, 88, /* 136 - 143 */
854 72, 128, 73, 98, 74, 132, 75, 121, /* 144 - 151 */
855 76, 102, 77, 124, 78, 132, 79, 106, /* 152 - 159 */
856 80, 97, 81, 160, 82, 99, 83, 134, /* 160 - 167 */
857 84, 86, 85, 95, 86, 160, 87, 100, /* 168 - 175 */
858 88, 113, 89, 98, 90, 107, 91, 122, /* 176 - 183 */
859 92, 111, 93, 102, 94, 126, 95, 150, /* 184 - 191 */
860 96, 128, 97, 130, 98, 133, 99, 195, /* 192 - 199 */
861 100, 128, 101, 123, 102, 164, 103, 138, /* 200 - 207 */
862 104, 145, 105, 146, 106, 109, 107, 149, /* 208 - 215 */
863 108, 200, 109, 146, 110, 170, 111, 157, /* 216 - 223 */
864 112, 128, 113, 130, 114, 182, 115, 132, /* 224 - 231 */
865 116, 200, 117, 132, 118, 158, 119, 206, /* 232 - 239 */
866 120, 240, 121, 162, 122, 147, 123, 152, /* 240 - 247 */
867 124, 166, 125, 214, 126, 138, 127, 153, /* 248 - 255 */
871 /* Return the number of multiplications required to calculate
872 powi(x,n) where n is less than POWI_TABLE_SIZE. This is a
873 subroutine of powi_cost. CACHE is an array indicating
874 which exponents have already been calculated. */
877 powi_lookup_cost (unsigned HOST_WIDE_INT n, bool *cache)
879 /* If we've already calculated this exponent, then this evaluation
880 doesn't require any additional multiplications. */
885 return powi_lookup_cost (n - powi_table[n], cache)
886 + powi_lookup_cost (powi_table[n], cache) + 1;
889 /* Return the number of multiplications required to calculate
890 powi(x,n) for an arbitrary x, given the exponent N. This
891 function needs to be kept in sync with powi_as_mults below. */
894 powi_cost (HOST_WIDE_INT n)
896 bool cache[POWI_TABLE_SIZE];
897 unsigned HOST_WIDE_INT digit;
898 unsigned HOST_WIDE_INT val;
904 /* Ignore the reciprocal when calculating the cost. */
905 val = (n < 0) ? -n : n;
907 /* Initialize the exponent cache. */
908 memset (cache, 0, POWI_TABLE_SIZE * sizeof (bool));
913 while (val >= POWI_TABLE_SIZE)
917 digit = val & ((1 << POWI_WINDOW_SIZE) - 1);
918 result += powi_lookup_cost (digit, cache)
919 + POWI_WINDOW_SIZE + 1;
920 val >>= POWI_WINDOW_SIZE;
929 return result + powi_lookup_cost (val, cache);
932 /* Recursive subroutine of powi_as_mults. This function takes the
933 array, CACHE, of already calculated exponents and an exponent N and
934 returns a tree that corresponds to CACHE[1]**N, with type TYPE. */
937 powi_as_mults_1 (gimple_stmt_iterator *gsi, location_t loc, tree type,
938 HOST_WIDE_INT n, tree *cache, tree target)
940 tree op0, op1, ssa_target;
941 unsigned HOST_WIDE_INT digit;
944 if (n < POWI_TABLE_SIZE && cache[n])
947 ssa_target = make_ssa_name (target, NULL);
949 if (n < POWI_TABLE_SIZE)
951 cache[n] = ssa_target;
952 op0 = powi_as_mults_1 (gsi, loc, type, n - powi_table[n], cache, target);
953 op1 = powi_as_mults_1 (gsi, loc, type, powi_table[n], cache, target);
957 digit = n & ((1 << POWI_WINDOW_SIZE) - 1);
958 op0 = powi_as_mults_1 (gsi, loc, type, n - digit, cache, target);
959 op1 = powi_as_mults_1 (gsi, loc, type, digit, cache, target);
963 op0 = powi_as_mults_1 (gsi, loc, type, n >> 1, cache, target);
967 mult_stmt = gimple_build_assign_with_ops (MULT_EXPR, ssa_target, op0, op1);
968 gsi_insert_before (gsi, mult_stmt, GSI_SAME_STMT);
973 /* Convert ARG0**N to a tree of multiplications of ARG0 with itself.
974 This function needs to be kept in sync with powi_cost above. */
977 powi_as_mults (gimple_stmt_iterator *gsi, location_t loc,
978 tree arg0, HOST_WIDE_INT n)
980 tree cache[POWI_TABLE_SIZE], result, type = TREE_TYPE (arg0), target;
984 return build_real (type, dconst1);
986 memset (cache, 0, sizeof (cache));
989 target = create_tmp_var (type, "powmult");
990 add_referenced_var (target);
992 result = powi_as_mults_1 (gsi, loc, type, (n < 0) ? -n : n, cache, target);
997 /* If the original exponent was negative, reciprocate the result. */
998 target = make_ssa_name (target, NULL);
999 div_stmt = gimple_build_assign_with_ops (RDIV_EXPR, target,
1000 build_real (type, dconst1),
1002 gsi_insert_before (gsi, div_stmt, GSI_SAME_STMT);
1007 /* ARG0 and N are the two arguments to a powi builtin in GSI with
1008 location info LOC. If the arguments are appropriate, create an
1009 equivalent sequence of statements prior to GSI using an optimal
1010 number of multiplications, and return an expession holding the
1014 gimple_expand_builtin_powi (gimple_stmt_iterator *gsi, location_t loc,
1015 tree arg0, HOST_WIDE_INT n)
1017 /* Avoid largest negative number. */
1019 && ((n >= -1 && n <= 2)
1020 || (optimize_function_for_speed_p (cfun)
1021 && powi_cost (n) <= POWI_MAX_MULTS)))
1022 return powi_as_mults (gsi, loc, arg0, n);
1027 /* Go through all calls to sin, cos and cexpi and call execute_cse_sincos_1
1028 on the SSA_NAME argument of each of them. Also expand powi(x,n) into
1029 an optimal number of multiplies, when n is a constant. */
1032 execute_cse_sincos (void)
1035 bool cfg_changed = false;
1037 calculate_dominance_info (CDI_DOMINATORS);
1038 memset (&sincos_stats, 0, sizeof (sincos_stats));
1042 gimple_stmt_iterator gsi;
1044 for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1046 gimple stmt = gsi_stmt (gsi);
1049 if (is_gimple_call (stmt)
1050 && gimple_call_lhs (stmt)
1051 && (fndecl = gimple_call_fndecl (stmt))
1052 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
1054 tree arg, arg0, arg1, result;
1058 switch (DECL_FUNCTION_CODE (fndecl))
1060 CASE_FLT_FN (BUILT_IN_COS):
1061 CASE_FLT_FN (BUILT_IN_SIN):
1062 CASE_FLT_FN (BUILT_IN_CEXPI):
1063 arg = gimple_call_arg (stmt, 0);
1064 if (TREE_CODE (arg) == SSA_NAME)
1065 cfg_changed |= execute_cse_sincos_1 (arg);
1068 CASE_FLT_FN (BUILT_IN_POWI):
1069 arg0 = gimple_call_arg (stmt, 0);
1070 arg1 = gimple_call_arg (stmt, 1);
1071 if (!host_integerp (arg1, 0))
1074 n = TREE_INT_CST_LOW (arg1);
1075 loc = gimple_location (stmt);
1076 result = gimple_expand_builtin_powi (&gsi, loc, arg0, n);
1080 tree lhs = gimple_get_lhs (stmt);
1081 gimple new_stmt = gimple_build_assign (lhs, result);
1082 gimple_set_location (new_stmt, loc);
1083 unlink_stmt_vdef (stmt);
1084 gsi_replace (&gsi, new_stmt, true);
1094 statistics_counter_event (cfun, "sincos statements inserted",
1095 sincos_stats.inserted);
1097 free_dominance_info (CDI_DOMINATORS);
1098 return cfg_changed ? TODO_cleanup_cfg : 0;
1102 gate_cse_sincos (void)
1104 /* We no longer require either sincos or cexp, since powi expansion
1105 piggybacks on this pass. */
1109 struct gimple_opt_pass pass_cse_sincos =
1113 "sincos", /* name */
1114 gate_cse_sincos, /* gate */
1115 execute_cse_sincos, /* execute */
1118 0, /* static_pass_number */
1119 TV_NONE, /* tv_id */
1120 PROP_ssa, /* properties_required */
1121 0, /* properties_provided */
1122 0, /* properties_destroyed */
1123 0, /* todo_flags_start */
1124 TODO_dump_func | TODO_update_ssa | TODO_verify_ssa
1125 | TODO_verify_stmts /* todo_flags_finish */
1129 /* A symbolic number is used to detect byte permutation and selection
1130 patterns. Therefore the field N contains an artificial number
1131 consisting of byte size markers:
1133 0 - byte has the value 0
1134 1..size - byte contains the content of the byte
1135 number indexed with that value minus one */
1137 struct symbolic_number {
1138 unsigned HOST_WIDEST_INT n;
1142 /* Perform a SHIFT or ROTATE operation by COUNT bits on symbolic
1143 number N. Return false if the requested operation is not permitted
1144 on a symbolic number. */
1147 do_shift_rotate (enum tree_code code,
1148 struct symbolic_number *n,
1154 /* Zero out the extra bits of N in order to avoid them being shifted
1155 into the significant bits. */
1156 if (n->size < (int)sizeof (HOST_WIDEST_INT))
1157 n->n &= ((unsigned HOST_WIDEST_INT)1 << (n->size * BITS_PER_UNIT)) - 1;
1168 n->n = (n->n << count) | (n->n >> ((n->size * BITS_PER_UNIT) - count));
1171 n->n = (n->n >> count) | (n->n << ((n->size * BITS_PER_UNIT) - count));
1179 /* Perform sanity checking for the symbolic number N and the gimple
1183 verify_symbolic_number_p (struct symbolic_number *n, gimple stmt)
1187 lhs_type = gimple_expr_type (stmt);
1189 if (TREE_CODE (lhs_type) != INTEGER_TYPE)
1192 if (TYPE_PRECISION (lhs_type) != n->size * BITS_PER_UNIT)
1198 /* find_bswap_1 invokes itself recursively with N and tries to perform
1199 the operation given by the rhs of STMT on the result. If the
1200 operation could successfully be executed the function returns the
1201 tree expression of the source operand and NULL otherwise. */
1204 find_bswap_1 (gimple stmt, struct symbolic_number *n, int limit)
1206 enum tree_code code;
1207 tree rhs1, rhs2 = NULL;
1208 gimple rhs1_stmt, rhs2_stmt;
1210 enum gimple_rhs_class rhs_class;
1212 if (!limit || !is_gimple_assign (stmt))
1215 rhs1 = gimple_assign_rhs1 (stmt);
1217 if (TREE_CODE (rhs1) != SSA_NAME)
1220 code = gimple_assign_rhs_code (stmt);
1221 rhs_class = gimple_assign_rhs_class (stmt);
1222 rhs1_stmt = SSA_NAME_DEF_STMT (rhs1);
1224 if (rhs_class == GIMPLE_BINARY_RHS)
1225 rhs2 = gimple_assign_rhs2 (stmt);
1227 /* Handle unary rhs and binary rhs with integer constants as second
1230 if (rhs_class == GIMPLE_UNARY_RHS
1231 || (rhs_class == GIMPLE_BINARY_RHS
1232 && TREE_CODE (rhs2) == INTEGER_CST))
1234 if (code != BIT_AND_EXPR
1235 && code != LSHIFT_EXPR
1236 && code != RSHIFT_EXPR
1237 && code != LROTATE_EXPR
1238 && code != RROTATE_EXPR
1240 && code != CONVERT_EXPR)
1243 source_expr1 = find_bswap_1 (rhs1_stmt, n, limit - 1);
1245 /* If find_bswap_1 returned NULL STMT is a leaf node and we have
1246 to initialize the symbolic number. */
1249 /* Set up the symbolic number N by setting each byte to a
1250 value between 1 and the byte size of rhs1. The highest
1251 order byte is set to n->size and the lowest order
1253 n->size = TYPE_PRECISION (TREE_TYPE (rhs1));
1254 if (n->size % BITS_PER_UNIT != 0)
1256 n->size /= BITS_PER_UNIT;
1257 n->n = (sizeof (HOST_WIDEST_INT) < 8 ? 0 :
1258 (unsigned HOST_WIDEST_INT)0x08070605 << 32 | 0x04030201);
1260 if (n->size < (int)sizeof (HOST_WIDEST_INT))
1261 n->n &= ((unsigned HOST_WIDEST_INT)1 <<
1262 (n->size * BITS_PER_UNIT)) - 1;
1264 source_expr1 = rhs1;
1272 unsigned HOST_WIDEST_INT val = widest_int_cst_value (rhs2);
1273 unsigned HOST_WIDEST_INT tmp = val;
1275 /* Only constants masking full bytes are allowed. */
1276 for (i = 0; i < n->size; i++, tmp >>= BITS_PER_UNIT)
1277 if ((tmp & 0xff) != 0 && (tmp & 0xff) != 0xff)
1287 if (!do_shift_rotate (code, n, (int)TREE_INT_CST_LOW (rhs2)))
1294 type_size = TYPE_PRECISION (gimple_expr_type (stmt));
1295 if (type_size % BITS_PER_UNIT != 0)
1298 if (type_size / BITS_PER_UNIT < (int)(sizeof (HOST_WIDEST_INT)))
1300 /* If STMT casts to a smaller type mask out the bits not
1301 belonging to the target type. */
1302 n->n &= ((unsigned HOST_WIDEST_INT)1 << type_size) - 1;
1304 n->size = type_size / BITS_PER_UNIT;
1310 return verify_symbolic_number_p (n, stmt) ? source_expr1 : NULL;
1313 /* Handle binary rhs. */
1315 if (rhs_class == GIMPLE_BINARY_RHS)
1317 struct symbolic_number n1, n2;
1320 if (code != BIT_IOR_EXPR)
1323 if (TREE_CODE (rhs2) != SSA_NAME)
1326 rhs2_stmt = SSA_NAME_DEF_STMT (rhs2);
1331 source_expr1 = find_bswap_1 (rhs1_stmt, &n1, limit - 1);
1336 source_expr2 = find_bswap_1 (rhs2_stmt, &n2, limit - 1);
1338 if (source_expr1 != source_expr2
1339 || n1.size != n2.size)
1345 if (!verify_symbolic_number_p (n, stmt))
1352 return source_expr1;
1357 /* Check if STMT completes a bswap implementation consisting of ORs,
1358 SHIFTs and ANDs. Return the source tree expression on which the
1359 byte swap is performed and NULL if no bswap was found. */
1362 find_bswap (gimple stmt)
1364 /* The number which the find_bswap result should match in order to
1365 have a full byte swap. The number is shifted to the left according
1366 to the size of the symbolic number before using it. */
1367 unsigned HOST_WIDEST_INT cmp =
1368 sizeof (HOST_WIDEST_INT) < 8 ? 0 :
1369 (unsigned HOST_WIDEST_INT)0x01020304 << 32 | 0x05060708;
1371 struct symbolic_number n;
1374 /* The last parameter determines the depth search limit. It usually
1375 correlates directly to the number of bytes to be touched. We
1376 increase that number by one here in order to also cover signed ->
1377 unsigned conversions of the src operand as can be seen in
1379 source_expr = find_bswap_1 (stmt, &n,
1381 TYPE_SIZE_UNIT (gimple_expr_type (stmt))) + 1);
1386 /* Zero out the extra bits of N and CMP. */
1387 if (n.size < (int)sizeof (HOST_WIDEST_INT))
1389 unsigned HOST_WIDEST_INT mask =
1390 ((unsigned HOST_WIDEST_INT)1 << (n.size * BITS_PER_UNIT)) - 1;
1393 cmp >>= (sizeof (HOST_WIDEST_INT) - n.size) * BITS_PER_UNIT;
1396 /* A complete byte swap should make the symbolic number to start
1397 with the largest digit in the highest order byte. */
1404 /* Find manual byte swap implementations and turn them into a bswap
1405 builtin invokation. */
1408 execute_optimize_bswap (void)
1411 bool bswap32_p, bswap64_p;
1412 bool changed = false;
1413 tree bswap32_type = NULL_TREE, bswap64_type = NULL_TREE;
1415 if (BITS_PER_UNIT != 8)
1418 if (sizeof (HOST_WIDEST_INT) < 8)
1421 bswap32_p = (built_in_decls[BUILT_IN_BSWAP32]
1422 && optab_handler (bswap_optab, SImode) != CODE_FOR_nothing);
1423 bswap64_p = (built_in_decls[BUILT_IN_BSWAP64]
1424 && (optab_handler (bswap_optab, DImode) != CODE_FOR_nothing
1425 || (bswap32_p && word_mode == SImode)));
1427 if (!bswap32_p && !bswap64_p)
1430 /* Determine the argument type of the builtins. The code later on
1431 assumes that the return and argument type are the same. */
1434 tree fndecl = built_in_decls[BUILT_IN_BSWAP32];
1435 bswap32_type = TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fndecl)));
1440 tree fndecl = built_in_decls[BUILT_IN_BSWAP64];
1441 bswap64_type = TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fndecl)));
1444 memset (&bswap_stats, 0, sizeof (bswap_stats));
1448 gimple_stmt_iterator gsi;
1450 for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); gsi_next (&gsi))
1452 gimple stmt = gsi_stmt (gsi);
1453 tree bswap_src, bswap_type;
1455 tree fndecl = NULL_TREE;
1459 if (!is_gimple_assign (stmt)
1460 || gimple_assign_rhs_code (stmt) != BIT_IOR_EXPR)
1463 type_size = TYPE_PRECISION (gimple_expr_type (stmt));
1470 fndecl = built_in_decls[BUILT_IN_BSWAP32];
1471 bswap_type = bswap32_type;
1477 fndecl = built_in_decls[BUILT_IN_BSWAP64];
1478 bswap_type = bswap64_type;
1488 bswap_src = find_bswap (stmt);
1494 if (type_size == 32)
1495 bswap_stats.found_32bit++;
1497 bswap_stats.found_64bit++;
1499 bswap_tmp = bswap_src;
1501 /* Convert the src expression if necessary. */
1502 if (!useless_type_conversion_p (TREE_TYPE (bswap_tmp), bswap_type))
1504 gimple convert_stmt;
1506 bswap_tmp = create_tmp_var (bswap_type, "bswapsrc");
1507 add_referenced_var (bswap_tmp);
1508 bswap_tmp = make_ssa_name (bswap_tmp, NULL);
1510 convert_stmt = gimple_build_assign_with_ops (
1511 CONVERT_EXPR, bswap_tmp, bswap_src, NULL);
1512 gsi_insert_before (&gsi, convert_stmt, GSI_SAME_STMT);
1515 call = gimple_build_call (fndecl, 1, bswap_tmp);
1517 bswap_tmp = gimple_assign_lhs (stmt);
1519 /* Convert the result if necessary. */
1520 if (!useless_type_conversion_p (TREE_TYPE (bswap_tmp), bswap_type))
1522 gimple convert_stmt;
1524 bswap_tmp = create_tmp_var (bswap_type, "bswapdst");
1525 add_referenced_var (bswap_tmp);
1526 bswap_tmp = make_ssa_name (bswap_tmp, NULL);
1527 convert_stmt = gimple_build_assign_with_ops (
1528 CONVERT_EXPR, gimple_assign_lhs (stmt), bswap_tmp, NULL);
1529 gsi_insert_after (&gsi, convert_stmt, GSI_SAME_STMT);
1532 gimple_call_set_lhs (call, bswap_tmp);
1536 fprintf (dump_file, "%d bit bswap implementation found at: ",
1538 print_gimple_stmt (dump_file, stmt, 0, 0);
1541 gsi_insert_after (&gsi, call, GSI_SAME_STMT);
1542 gsi_remove (&gsi, true);
1546 statistics_counter_event (cfun, "32-bit bswap implementations found",
1547 bswap_stats.found_32bit);
1548 statistics_counter_event (cfun, "64-bit bswap implementations found",
1549 bswap_stats.found_64bit);
1551 return (changed ? TODO_dump_func | TODO_update_ssa | TODO_verify_ssa
1552 | TODO_verify_stmts : 0);
1556 gate_optimize_bswap (void)
1558 return flag_expensive_optimizations && optimize;
1561 struct gimple_opt_pass pass_optimize_bswap =
1566 gate_optimize_bswap, /* gate */
1567 execute_optimize_bswap, /* execute */
1570 0, /* static_pass_number */
1571 TV_NONE, /* tv_id */
1572 PROP_ssa, /* properties_required */
1573 0, /* properties_provided */
1574 0, /* properties_destroyed */
1575 0, /* todo_flags_start */
1576 0 /* todo_flags_finish */
1580 /* Return true if RHS is a suitable operand for a widening multiplication.
1581 There are two cases:
1583 - RHS makes some value twice as wide. Store that value in *NEW_RHS_OUT
1584 if so, and store its type in *TYPE_OUT.
1586 - RHS is an integer constant. Store that value in *NEW_RHS_OUT if so,
1587 but leave *TYPE_OUT untouched. */
1590 is_widening_mult_rhs_p (tree rhs, tree *type_out, tree *new_rhs_out)
1593 tree type, type1, rhs1;
1594 enum tree_code rhs_code;
1596 if (TREE_CODE (rhs) == SSA_NAME)
1598 type = TREE_TYPE (rhs);
1599 stmt = SSA_NAME_DEF_STMT (rhs);
1600 if (!is_gimple_assign (stmt))
1603 rhs_code = gimple_assign_rhs_code (stmt);
1604 if (TREE_CODE (type) == INTEGER_TYPE
1605 ? !CONVERT_EXPR_CODE_P (rhs_code)
1606 : rhs_code != FIXED_CONVERT_EXPR)
1609 rhs1 = gimple_assign_rhs1 (stmt);
1610 type1 = TREE_TYPE (rhs1);
1611 if (TREE_CODE (type1) != TREE_CODE (type)
1612 || TYPE_PRECISION (type1) * 2 != TYPE_PRECISION (type))
1615 *new_rhs_out = rhs1;
1620 if (TREE_CODE (rhs) == INTEGER_CST)
1630 /* Return true if STMT performs a widening multiplication. If so,
1631 store the unwidened types of the operands in *TYPE1_OUT and *TYPE2_OUT
1632 respectively. Also fill *RHS1_OUT and *RHS2_OUT such that converting
1633 those operands to types *TYPE1_OUT and *TYPE2_OUT would give the
1634 operands of the multiplication. */
1637 is_widening_mult_p (gimple stmt,
1638 tree *type1_out, tree *rhs1_out,
1639 tree *type2_out, tree *rhs2_out)
1643 type = TREE_TYPE (gimple_assign_lhs (stmt));
1644 if (TREE_CODE (type) != INTEGER_TYPE
1645 && TREE_CODE (type) != FIXED_POINT_TYPE)
1648 if (!is_widening_mult_rhs_p (gimple_assign_rhs1 (stmt), type1_out, rhs1_out))
1651 if (!is_widening_mult_rhs_p (gimple_assign_rhs2 (stmt), type2_out, rhs2_out))
1654 if (*type1_out == NULL)
1656 if (*type2_out == NULL || !int_fits_type_p (*rhs1_out, *type2_out))
1658 *type1_out = *type2_out;
1661 if (*type2_out == NULL)
1663 if (!int_fits_type_p (*rhs2_out, *type1_out))
1665 *type2_out = *type1_out;
1671 /* Process a single gimple statement STMT, which has a MULT_EXPR as
1672 its rhs, and try to convert it into a WIDEN_MULT_EXPR. The return
1673 value is true iff we converted the statement. */
1676 convert_mult_to_widen (gimple stmt)
1678 tree lhs, rhs1, rhs2, type, type1, type2;
1679 enum insn_code handler;
1681 lhs = gimple_assign_lhs (stmt);
1682 type = TREE_TYPE (lhs);
1683 if (TREE_CODE (type) != INTEGER_TYPE)
1686 if (!is_widening_mult_p (stmt, &type1, &rhs1, &type2, &rhs2))
1689 if (TYPE_UNSIGNED (type1) && TYPE_UNSIGNED (type2))
1690 handler = optab_handler (umul_widen_optab, TYPE_MODE (type));
1691 else if (!TYPE_UNSIGNED (type1) && !TYPE_UNSIGNED (type2))
1692 handler = optab_handler (smul_widen_optab, TYPE_MODE (type));
1694 handler = optab_handler (usmul_widen_optab, TYPE_MODE (type));
1696 if (handler == CODE_FOR_nothing)
1699 gimple_assign_set_rhs1 (stmt, fold_convert (type1, rhs1));
1700 gimple_assign_set_rhs2 (stmt, fold_convert (type2, rhs2));
1701 gimple_assign_set_rhs_code (stmt, WIDEN_MULT_EXPR);
1703 widen_mul_stats.widen_mults_inserted++;
1707 /* Process a single gimple statement STMT, which is found at the
1708 iterator GSI and has a either a PLUS_EXPR or a MINUS_EXPR as its
1709 rhs (given by CODE), and try to convert it into a
1710 WIDEN_MULT_PLUS_EXPR or a WIDEN_MULT_MINUS_EXPR. The return value
1711 is true iff we converted the statement. */
1714 convert_plusminus_to_widen (gimple_stmt_iterator *gsi, gimple stmt,
1715 enum tree_code code)
1717 gimple rhs1_stmt = NULL, rhs2_stmt = NULL;
1718 tree type, type1, type2;
1719 tree lhs, rhs1, rhs2, mult_rhs1, mult_rhs2, add_rhs;
1720 enum tree_code rhs1_code = ERROR_MARK, rhs2_code = ERROR_MARK;
1722 enum tree_code wmult_code;
1724 lhs = gimple_assign_lhs (stmt);
1725 type = TREE_TYPE (lhs);
1726 if (TREE_CODE (type) != INTEGER_TYPE
1727 && TREE_CODE (type) != FIXED_POINT_TYPE)
1730 if (code == MINUS_EXPR)
1731 wmult_code = WIDEN_MULT_MINUS_EXPR;
1733 wmult_code = WIDEN_MULT_PLUS_EXPR;
1735 rhs1 = gimple_assign_rhs1 (stmt);
1736 rhs2 = gimple_assign_rhs2 (stmt);
1738 if (TREE_CODE (rhs1) == SSA_NAME)
1740 rhs1_stmt = SSA_NAME_DEF_STMT (rhs1);
1741 if (is_gimple_assign (rhs1_stmt))
1742 rhs1_code = gimple_assign_rhs_code (rhs1_stmt);
1747 if (TREE_CODE (rhs2) == SSA_NAME)
1749 rhs2_stmt = SSA_NAME_DEF_STMT (rhs2);
1750 if (is_gimple_assign (rhs2_stmt))
1751 rhs2_code = gimple_assign_rhs_code (rhs2_stmt);
1756 if (code == PLUS_EXPR && rhs1_code == MULT_EXPR)
1758 if (!is_widening_mult_p (rhs1_stmt, &type1, &mult_rhs1,
1759 &type2, &mult_rhs2))
1763 else if (rhs2_code == MULT_EXPR)
1765 if (!is_widening_mult_p (rhs2_stmt, &type1, &mult_rhs1,
1766 &type2, &mult_rhs2))
1770 else if (code == PLUS_EXPR && rhs1_code == WIDEN_MULT_EXPR)
1772 mult_rhs1 = gimple_assign_rhs1 (rhs1_stmt);
1773 mult_rhs2 = gimple_assign_rhs2 (rhs1_stmt);
1774 type1 = TREE_TYPE (mult_rhs1);
1775 type2 = TREE_TYPE (mult_rhs2);
1778 else if (rhs2_code == WIDEN_MULT_EXPR)
1780 mult_rhs1 = gimple_assign_rhs1 (rhs2_stmt);
1781 mult_rhs2 = gimple_assign_rhs2 (rhs2_stmt);
1782 type1 = TREE_TYPE (mult_rhs1);
1783 type2 = TREE_TYPE (mult_rhs2);
1789 if (TYPE_UNSIGNED (type1) != TYPE_UNSIGNED (type2))
1792 /* Verify that the machine can perform a widening multiply
1793 accumulate in this mode/signedness combination, otherwise
1794 this transformation is likely to pessimize code. */
1795 this_optab = optab_for_tree_code (wmult_code, type1, optab_default);
1796 if (optab_handler (this_optab, TYPE_MODE (type)) == CODE_FOR_nothing)
1799 /* ??? May need some type verification here? */
1801 gimple_assign_set_rhs_with_ops_1 (gsi, wmult_code,
1802 fold_convert (type1, mult_rhs1),
1803 fold_convert (type2, mult_rhs2),
1805 update_stmt (gsi_stmt (*gsi));
1806 widen_mul_stats.maccs_inserted++;
1810 /* Combine the multiplication at MUL_STMT with operands MULOP1 and MULOP2
1811 with uses in additions and subtractions to form fused multiply-add
1812 operations. Returns true if successful and MUL_STMT should be removed. */
1815 convert_mult_to_fma (gimple mul_stmt, tree op1, tree op2)
1817 tree mul_result = gimple_get_lhs (mul_stmt);
1818 tree type = TREE_TYPE (mul_result);
1819 gimple use_stmt, neguse_stmt, fma_stmt;
1820 use_operand_p use_p;
1821 imm_use_iterator imm_iter;
1823 if (FLOAT_TYPE_P (type)
1824 && flag_fp_contract_mode == FP_CONTRACT_OFF)
1827 /* We don't want to do bitfield reduction ops. */
1828 if (INTEGRAL_TYPE_P (type)
1829 && (TYPE_PRECISION (type)
1830 != GET_MODE_PRECISION (TYPE_MODE (type))))
1833 /* If the target doesn't support it, don't generate it. We assume that
1834 if fma isn't available then fms, fnma or fnms are not either. */
1835 if (optab_handler (fma_optab, TYPE_MODE (type)) == CODE_FOR_nothing)
1838 /* Make sure that the multiplication statement becomes dead after
1839 the transformation, thus that all uses are transformed to FMAs.
1840 This means we assume that an FMA operation has the same cost
1842 FOR_EACH_IMM_USE_FAST (use_p, imm_iter, mul_result)
1844 enum tree_code use_code;
1845 tree result = mul_result;
1846 bool negate_p = false;
1848 use_stmt = USE_STMT (use_p);
1850 if (is_gimple_debug (use_stmt))
1853 /* For now restrict this operations to single basic blocks. In theory
1854 we would want to support sinking the multiplication in
1860 to form a fma in the then block and sink the multiplication to the
1862 if (gimple_bb (use_stmt) != gimple_bb (mul_stmt))
1865 if (!is_gimple_assign (use_stmt))
1868 use_code = gimple_assign_rhs_code (use_stmt);
1870 /* A negate on the multiplication leads to FNMA. */
1871 if (use_code == NEGATE_EXPR)
1876 result = gimple_assign_lhs (use_stmt);
1878 /* Make sure the negate statement becomes dead with this
1879 single transformation. */
1880 if (!single_imm_use (gimple_assign_lhs (use_stmt),
1881 &use_p, &neguse_stmt))
1884 /* Make sure the multiplication isn't also used on that stmt. */
1885 FOR_EACH_SSA_TREE_OPERAND (use, neguse_stmt, iter, SSA_OP_USE)
1886 if (use == mul_result)
1890 use_stmt = neguse_stmt;
1891 if (gimple_bb (use_stmt) != gimple_bb (mul_stmt))
1893 if (!is_gimple_assign (use_stmt))
1896 use_code = gimple_assign_rhs_code (use_stmt);
1903 if (gimple_assign_rhs2 (use_stmt) == result)
1904 negate_p = !negate_p;
1909 /* FMA can only be formed from PLUS and MINUS. */
1913 /* We can't handle a * b + a * b. */
1914 if (gimple_assign_rhs1 (use_stmt) == gimple_assign_rhs2 (use_stmt))
1917 /* While it is possible to validate whether or not the exact form
1918 that we've recognized is available in the backend, the assumption
1919 is that the transformation is never a loss. For instance, suppose
1920 the target only has the plain FMA pattern available. Consider
1921 a*b-c -> fma(a,b,-c): we've exchanged MUL+SUB for FMA+NEG, which
1922 is still two operations. Consider -(a*b)-c -> fma(-a,b,-c): we
1923 still have 3 operations, but in the FMA form the two NEGs are
1924 independant and could be run in parallel. */
1927 FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, mul_result)
1929 gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt);
1930 enum tree_code use_code;
1931 tree addop, mulop1 = op1, result = mul_result;
1932 bool negate_p = false;
1934 if (is_gimple_debug (use_stmt))
1937 use_code = gimple_assign_rhs_code (use_stmt);
1938 if (use_code == NEGATE_EXPR)
1940 result = gimple_assign_lhs (use_stmt);
1941 single_imm_use (gimple_assign_lhs (use_stmt), &use_p, &neguse_stmt);
1942 gsi_remove (&gsi, true);
1943 release_defs (use_stmt);
1945 use_stmt = neguse_stmt;
1946 gsi = gsi_for_stmt (use_stmt);
1947 use_code = gimple_assign_rhs_code (use_stmt);
1951 if (gimple_assign_rhs1 (use_stmt) == result)
1953 addop = gimple_assign_rhs2 (use_stmt);
1954 /* a * b - c -> a * b + (-c) */
1955 if (gimple_assign_rhs_code (use_stmt) == MINUS_EXPR)
1956 addop = force_gimple_operand_gsi (&gsi,
1957 build1 (NEGATE_EXPR,
1959 true, NULL_TREE, true,
1964 addop = gimple_assign_rhs1 (use_stmt);
1965 /* a - b * c -> (-b) * c + a */
1966 if (gimple_assign_rhs_code (use_stmt) == MINUS_EXPR)
1967 negate_p = !negate_p;
1971 mulop1 = force_gimple_operand_gsi (&gsi,
1972 build1 (NEGATE_EXPR,
1974 true, NULL_TREE, true,
1977 fma_stmt = gimple_build_assign_with_ops3 (FMA_EXPR,
1978 gimple_assign_lhs (use_stmt),
1981 gsi_replace (&gsi, fma_stmt, true);
1982 widen_mul_stats.fmas_inserted++;
1988 /* Find integer multiplications where the operands are extended from
1989 smaller types, and replace the MULT_EXPR with a WIDEN_MULT_EXPR
1990 where appropriate. */
1993 execute_optimize_widening_mul (void)
1996 bool cfg_changed = false;
1998 memset (&widen_mul_stats, 0, sizeof (widen_mul_stats));
2002 gimple_stmt_iterator gsi;
2004 for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi);)
2006 gimple stmt = gsi_stmt (gsi);
2007 enum tree_code code;
2009 if (is_gimple_assign (stmt))
2011 code = gimple_assign_rhs_code (stmt);
2015 if (!convert_mult_to_widen (stmt)
2016 && convert_mult_to_fma (stmt,
2017 gimple_assign_rhs1 (stmt),
2018 gimple_assign_rhs2 (stmt)))
2020 gsi_remove (&gsi, true);
2021 release_defs (stmt);
2028 convert_plusminus_to_widen (&gsi, stmt, code);
2034 else if (is_gimple_call (stmt)
2035 && gimple_call_lhs (stmt))
2037 tree fndecl = gimple_call_fndecl (stmt);
2039 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
2041 switch (DECL_FUNCTION_CODE (fndecl))
2046 if (TREE_CODE (gimple_call_arg (stmt, 1)) == REAL_CST
2047 && REAL_VALUES_EQUAL
2048 (TREE_REAL_CST (gimple_call_arg (stmt, 1)),
2050 && convert_mult_to_fma (stmt,
2051 gimple_call_arg (stmt, 0),
2052 gimple_call_arg (stmt, 0)))
2054 unlink_stmt_vdef (stmt);
2055 gsi_remove (&gsi, true);
2056 release_defs (stmt);
2057 if (gimple_purge_dead_eh_edges (bb))
2071 statistics_counter_event (cfun, "widening multiplications inserted",
2072 widen_mul_stats.widen_mults_inserted);
2073 statistics_counter_event (cfun, "widening maccs inserted",
2074 widen_mul_stats.maccs_inserted);
2075 statistics_counter_event (cfun, "fused multiply-adds inserted",
2076 widen_mul_stats.fmas_inserted);
2078 return cfg_changed ? TODO_cleanup_cfg : 0;
2082 gate_optimize_widening_mul (void)
2084 return flag_expensive_optimizations && optimize;
2087 struct gimple_opt_pass pass_optimize_widening_mul =
2091 "widening_mul", /* name */
2092 gate_optimize_widening_mul, /* gate */
2093 execute_optimize_widening_mul, /* execute */
2096 0, /* static_pass_number */
2097 TV_NONE, /* tv_id */
2098 PROP_ssa, /* properties_required */
2099 0, /* properties_provided */
2100 0, /* properties_destroyed */
2101 0, /* todo_flags_start */
2105 | TODO_update_ssa /* todo_flags_finish */