1 /* Analysis Utilities for Loop Vectorization.
2 Copyright (C) 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
3 Contributed by Dorit Nuzman <dorit@il.ibm.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 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/>. */
23 #include "coretypes.h"
28 #include "basic-block.h"
29 #include "diagnostic.h"
30 #include "tree-flow.h"
31 #include "tree-dump.h"
36 #include "tree-data-ref.h"
37 #include "tree-vectorizer.h"
41 /* Function prototypes */
42 static void vect_pattern_recog_1
43 (gimple (* ) (gimple
, tree
*, tree
*), gimple_stmt_iterator
);
44 static bool widened_name_p (tree
, gimple
, tree
*, gimple
*);
46 /* Pattern recognition functions */
47 static gimple
vect_recog_widen_sum_pattern (gimple
, tree
*, tree
*);
48 static gimple
vect_recog_widen_mult_pattern (gimple
, tree
*, tree
*);
49 static gimple
vect_recog_dot_prod_pattern (gimple
, tree
*, tree
*);
50 static gimple
vect_recog_pow_pattern (gimple
, tree
*, tree
*);
51 static vect_recog_func_ptr vect_vect_recog_func_ptrs
[NUM_PATTERNS
] = {
52 vect_recog_widen_mult_pattern
,
53 vect_recog_widen_sum_pattern
,
54 vect_recog_dot_prod_pattern
,
55 vect_recog_pow_pattern
};
58 /* Function widened_name_p
60 Check whether NAME, an ssa-name used in USE_STMT,
61 is a result of a type-promotion, such that:
62 DEF_STMT: NAME = NOP (name0)
63 where the type of name0 (HALF_TYPE) is smaller than the type of NAME.
67 widened_name_p (tree name
, gimple use_stmt
, tree
*half_type
, gimple
*def_stmt
)
71 loop_vec_info loop_vinfo
;
72 stmt_vec_info stmt_vinfo
;
73 tree type
= TREE_TYPE (name
);
75 enum vect_def_type dt
;
78 stmt_vinfo
= vinfo_for_stmt (use_stmt
);
79 loop_vinfo
= STMT_VINFO_LOOP_VINFO (stmt_vinfo
);
81 if (!vect_is_simple_use (name
, loop_vinfo
, def_stmt
, &def
, &dt
))
84 if (dt
!= vect_internal_def
85 && dt
!= vect_external_def
&& dt
!= vect_constant_def
)
91 if (!is_gimple_assign (*def_stmt
))
94 if (gimple_assign_rhs_code (*def_stmt
) != NOP_EXPR
)
97 oprnd0
= gimple_assign_rhs1 (*def_stmt
);
99 *half_type
= TREE_TYPE (oprnd0
);
100 if (!INTEGRAL_TYPE_P (type
) || !INTEGRAL_TYPE_P (*half_type
)
101 || (TYPE_UNSIGNED (type
) != TYPE_UNSIGNED (*half_type
))
102 || (TYPE_PRECISION (type
) < (TYPE_PRECISION (*half_type
) * 2)))
105 if (!vect_is_simple_use (oprnd0
, loop_vinfo
, &dummy_gimple
, &dummy
, &dt
))
111 /* Helper to return a new temporary for pattern of TYPE for STMT. If STMT
112 is NULL, the caller must set SSA_NAME_DEF_STMT for the returned SSA var. */
115 vect_recog_temp_ssa_var (tree type
, gimple stmt
)
117 tree var
= create_tmp_var (type
, "patt");
119 add_referenced_var (var
);
120 var
= make_ssa_name (var
, stmt
);
124 /* Function vect_recog_dot_prod_pattern
126 Try to find the following pattern:
132 sum_0 = phi <init, sum_1>
135 S3 x_T = (TYPE1) x_t;
136 S4 y_T = (TYPE1) y_t;
138 [S6 prod = (TYPE2) prod; #optional]
139 S7 sum_1 = prod + sum_0;
141 where 'TYPE1' is exactly double the size of type 'type', and 'TYPE2' is the
142 same size of 'TYPE1' or bigger. This is a special case of a reduction
147 * LAST_STMT: A stmt from which the pattern search begins. In the example,
148 when this function is called with S7, the pattern {S3,S4,S5,S6,S7} will be
153 * TYPE_IN: The type of the input arguments to the pattern.
155 * TYPE_OUT: The type of the output of this pattern.
157 * Return value: A new stmt that will be used to replace the sequence of
158 stmts that constitute the pattern. In this case it will be:
159 WIDEN_DOT_PRODUCT <x_t, y_t, sum_0>
161 Note: The dot-prod idiom is a widening reduction pattern that is
162 vectorized without preserving all the intermediate results. It
163 produces only N/2 (widened) results (by summing up pairs of
164 intermediate results) rather than all N results. Therefore, we
165 cannot allow this pattern when we want to get all the results and in
166 the correct order (as is the case when this computation is in an
167 inner-loop nested in an outer-loop that us being vectorized). */
170 vect_recog_dot_prod_pattern (gimple last_stmt
, tree
*type_in
, tree
*type_out
)
174 tree oprnd00
, oprnd01
;
175 stmt_vec_info stmt_vinfo
= vinfo_for_stmt (last_stmt
);
176 tree type
, half_type
;
179 loop_vec_info loop_info
= STMT_VINFO_LOOP_VINFO (stmt_vinfo
);
180 struct loop
*loop
= LOOP_VINFO_LOOP (loop_info
);
183 if (!is_gimple_assign (last_stmt
))
186 type
= gimple_expr_type (last_stmt
);
188 /* Look for the following pattern
192 DDPROD = (TYPE2) DPROD;
193 sum_1 = DDPROD + sum_0;
195 - DX is double the size of X
196 - DY is double the size of Y
197 - DX, DY, DPROD all have the same type
198 - sum is the same size of DPROD or bigger
199 - sum has been recognized as a reduction variable.
201 This is equivalent to:
202 DPROD = X w* Y; #widen mult
203 sum_1 = DPROD w+ sum_0; #widen summation
205 DPROD = X w* Y; #widen mult
206 sum_1 = DPROD + sum_0; #summation
209 /* Starting from LAST_STMT, follow the defs of its uses in search
210 of the above pattern. */
212 if (gimple_assign_rhs_code (last_stmt
) != PLUS_EXPR
)
215 if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo
))
217 /* Has been detected as widening-summation? */
219 stmt
= STMT_VINFO_RELATED_STMT (stmt_vinfo
);
220 type
= gimple_expr_type (stmt
);
221 if (gimple_assign_rhs_code (stmt
) != WIDEN_SUM_EXPR
)
223 oprnd0
= gimple_assign_rhs1 (stmt
);
224 oprnd1
= gimple_assign_rhs2 (stmt
);
225 half_type
= TREE_TYPE (oprnd0
);
231 if (STMT_VINFO_DEF_TYPE (stmt_vinfo
) != vect_reduction_def
)
233 oprnd0
= gimple_assign_rhs1 (last_stmt
);
234 oprnd1
= gimple_assign_rhs2 (last_stmt
);
235 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0
)) != TYPE_MAIN_VARIANT (type
)
236 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1
)) != TYPE_MAIN_VARIANT (type
))
240 if (widened_name_p (oprnd0
, stmt
, &half_type
, &def_stmt
))
243 oprnd0
= gimple_assign_rhs1 (stmt
);
249 /* So far so good. Since last_stmt was detected as a (summation) reduction,
250 we know that oprnd1 is the reduction variable (defined by a loop-header
251 phi), and oprnd0 is an ssa-name defined by a stmt in the loop body.
252 Left to check that oprnd0 is defined by a (widen_)mult_expr */
254 prod_type
= half_type
;
255 stmt
= SSA_NAME_DEF_STMT (oprnd0
);
256 /* FORNOW. Can continue analyzing the def-use chain when this stmt in a phi
257 inside the loop (in case we are analyzing an outer-loop). */
258 if (!is_gimple_assign (stmt
))
260 stmt_vinfo
= vinfo_for_stmt (stmt
);
261 gcc_assert (stmt_vinfo
);
262 if (STMT_VINFO_DEF_TYPE (stmt_vinfo
) != vect_internal_def
)
264 if (gimple_assign_rhs_code (stmt
) != MULT_EXPR
)
266 if (STMT_VINFO_IN_PATTERN_P (stmt_vinfo
))
268 /* Has been detected as a widening multiplication? */
270 stmt
= STMT_VINFO_RELATED_STMT (stmt_vinfo
);
271 if (gimple_assign_rhs_code (stmt
) != WIDEN_MULT_EXPR
)
273 stmt_vinfo
= vinfo_for_stmt (stmt
);
274 gcc_assert (stmt_vinfo
);
275 gcc_assert (STMT_VINFO_DEF_TYPE (stmt_vinfo
) == vect_internal_def
);
276 oprnd00
= gimple_assign_rhs1 (stmt
);
277 oprnd01
= gimple_assign_rhs2 (stmt
);
281 tree half_type0
, half_type1
;
285 oprnd0
= gimple_assign_rhs1 (stmt
);
286 oprnd1
= gimple_assign_rhs2 (stmt
);
287 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0
))
288 != TYPE_MAIN_VARIANT (prod_type
)
289 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1
))
290 != TYPE_MAIN_VARIANT (prod_type
))
292 if (!widened_name_p (oprnd0
, stmt
, &half_type0
, &def_stmt
))
294 oprnd00
= gimple_assign_rhs1 (def_stmt
);
295 if (!widened_name_p (oprnd1
, stmt
, &half_type1
, &def_stmt
))
297 oprnd01
= gimple_assign_rhs1 (def_stmt
);
298 if (TYPE_MAIN_VARIANT (half_type0
) != TYPE_MAIN_VARIANT (half_type1
))
300 if (TYPE_PRECISION (prod_type
) != TYPE_PRECISION (half_type0
) * 2)
304 half_type
= TREE_TYPE (oprnd00
);
305 *type_in
= half_type
;
308 /* Pattern detected. Create a stmt to be used to replace the pattern: */
309 var
= vect_recog_temp_ssa_var (type
, NULL
);
310 rhs
= build3 (DOT_PROD_EXPR
, type
, oprnd00
, oprnd01
, oprnd1
),
311 pattern_stmt
= gimple_build_assign (var
, rhs
);
313 if (vect_print_dump_info (REPORT_DETAILS
))
315 fprintf (vect_dump
, "vect_recog_dot_prod_pattern: detected: ");
316 print_gimple_stmt (vect_dump
, pattern_stmt
, 0, TDF_SLIM
);
319 /* We don't allow changing the order of the computation in the inner-loop
320 when doing outer-loop vectorization. */
321 if (nested_in_vect_loop_p (loop
, last_stmt
))
323 if (vect_print_dump_info (REPORT_DETAILS
))
324 fprintf (vect_dump
, "vect_recog_dot_prod_pattern: not allowed.");
331 /* Function vect_recog_widen_mult_pattern
333 Try to find the following pattern:
336 TYPE a_T, b_T, prod_T;
342 S5 prod_T = a_T * b_T;
344 where type 'TYPE' is at least double the size of type 'type'.
348 * LAST_STMT: A stmt from which the pattern search begins. In the example,
349 when this function is called with S5, the pattern {S3,S4,S5} is be detected.
353 * TYPE_IN: The type of the input arguments to the pattern.
355 * TYPE_OUT: The type of the output of this pattern.
357 * Return value: A new stmt that will be used to replace the sequence of
358 stmts that constitute the pattern. In this case it will be:
359 WIDEN_MULT <a_t, b_t>
363 vect_recog_widen_mult_pattern (gimple last_stmt
,
367 gimple def_stmt0
, def_stmt1
;
369 tree type
, half_type0
, half_type1
;
374 enum tree_code dummy_code
;
376 VEC (tree
, heap
) *dummy_vec
;
378 if (!is_gimple_assign (last_stmt
))
381 type
= gimple_expr_type (last_stmt
);
383 /* Starting from LAST_STMT, follow the defs of its uses in search
384 of the above pattern. */
386 if (gimple_assign_rhs_code (last_stmt
) != MULT_EXPR
)
389 oprnd0
= gimple_assign_rhs1 (last_stmt
);
390 oprnd1
= gimple_assign_rhs2 (last_stmt
);
391 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0
)) != TYPE_MAIN_VARIANT (type
)
392 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1
)) != TYPE_MAIN_VARIANT (type
))
395 /* Check argument 0 */
396 if (!widened_name_p (oprnd0
, last_stmt
, &half_type0
, &def_stmt0
))
398 oprnd0
= gimple_assign_rhs1 (def_stmt0
);
400 /* Check argument 1 */
401 if (!widened_name_p (oprnd1
, last_stmt
, &half_type1
, &def_stmt1
))
403 oprnd1
= gimple_assign_rhs1 (def_stmt1
);
405 if (TYPE_MAIN_VARIANT (half_type0
) != TYPE_MAIN_VARIANT (half_type1
))
408 /* Pattern detected. */
409 if (vect_print_dump_info (REPORT_DETAILS
))
410 fprintf (vect_dump
, "vect_recog_widen_mult_pattern: detected: ");
412 /* Check target support */
413 vectype
= get_vectype_for_scalar_type (half_type0
);
415 || !supportable_widening_operation (WIDEN_MULT_EXPR
, last_stmt
, vectype
,
416 &dummy
, &dummy
, &dummy_code
,
417 &dummy_code
, &dummy_int
, &dummy_vec
))
421 *type_out
= NULL_TREE
;
423 /* Pattern supported. Create a stmt to be used to replace the pattern: */
424 var
= vect_recog_temp_ssa_var (type
, NULL
);
425 pattern_stmt
= gimple_build_assign_with_ops (WIDEN_MULT_EXPR
, var
, oprnd0
,
427 SSA_NAME_DEF_STMT (var
) = pattern_stmt
;
429 if (vect_print_dump_info (REPORT_DETAILS
))
430 print_gimple_stmt (vect_dump
, pattern_stmt
, 0, TDF_SLIM
);
436 /* Function vect_recog_pow_pattern
438 Try to find the following pattern:
442 with POW being one of pow, powf, powi, powif and N being
447 * LAST_STMT: A stmt from which the pattern search begins.
451 * TYPE_IN: The type of the input arguments to the pattern.
453 * TYPE_OUT: The type of the output of this pattern.
455 * Return value: A new stmt that will be used to replace the sequence of
456 stmts that constitute the pattern. In this case it will be:
463 vect_recog_pow_pattern (gimple last_stmt
, tree
*type_in
, tree
*type_out
)
466 tree fn
, base
, exp
= NULL
;
470 if (!is_gimple_call (last_stmt
) || gimple_call_lhs (last_stmt
) == NULL
)
473 type
= gimple_expr_type (last_stmt
);
475 fn
= gimple_call_fndecl (last_stmt
);
476 switch (DECL_FUNCTION_CODE (fn
))
482 base
= gimple_call_arg (last_stmt
, 0);
483 exp
= gimple_call_arg (last_stmt
, 1);
484 if (TREE_CODE (exp
) != REAL_CST
485 && TREE_CODE (exp
) != INTEGER_CST
)
493 /* We now have a pow or powi builtin function call with a constant
496 *type_out
= NULL_TREE
;
498 /* Catch squaring. */
499 if ((host_integerp (exp
, 0)
500 && tree_low_cst (exp
, 0) == 2)
501 || (TREE_CODE (exp
) == REAL_CST
502 && REAL_VALUES_EQUAL (TREE_REAL_CST (exp
), dconst2
)))
504 *type_in
= TREE_TYPE (base
);
506 var
= vect_recog_temp_ssa_var (TREE_TYPE (base
), NULL
);
507 stmt
= gimple_build_assign_with_ops (MULT_EXPR
, var
, base
, base
);
508 SSA_NAME_DEF_STMT (var
) = stmt
;
512 /* Catch square root. */
513 if (TREE_CODE (exp
) == REAL_CST
514 && REAL_VALUES_EQUAL (TREE_REAL_CST (exp
), dconsthalf
))
516 tree newfn
= mathfn_built_in (TREE_TYPE (base
), BUILT_IN_SQRT
);
517 *type_in
= get_vectype_for_scalar_type (TREE_TYPE (base
));
520 gimple stmt
= gimple_build_call (newfn
, 1, base
);
521 if (vectorizable_function (stmt
, *type_in
, *type_in
)
524 var
= vect_recog_temp_ssa_var (TREE_TYPE (base
), stmt
);
525 gimple_call_set_lhs (stmt
, var
);
535 /* Function vect_recog_widen_sum_pattern
537 Try to find the following pattern:
540 TYPE x_T, sum = init;
542 sum_0 = phi <init, sum_1>
545 S3 sum_1 = x_T + sum_0;
547 where type 'TYPE' is at least double the size of type 'type', i.e - we're
548 summing elements of type 'type' into an accumulator of type 'TYPE'. This is
549 a special case of a reduction computation.
553 * LAST_STMT: A stmt from which the pattern search begins. In the example,
554 when this function is called with S3, the pattern {S2,S3} will be detected.
558 * TYPE_IN: The type of the input arguments to the pattern.
560 * TYPE_OUT: The type of the output of this pattern.
562 * Return value: A new stmt that will be used to replace the sequence of
563 stmts that constitute the pattern. In this case it will be:
564 WIDEN_SUM <x_t, sum_0>
566 Note: The widening-sum idiom is a widening reduction pattern that is
567 vectorized without preserving all the intermediate results. It
568 produces only N/2 (widened) results (by summing up pairs of
569 intermediate results) rather than all N results. Therefore, we
570 cannot allow this pattern when we want to get all the results and in
571 the correct order (as is the case when this computation is in an
572 inner-loop nested in an outer-loop that us being vectorized). */
575 vect_recog_widen_sum_pattern (gimple last_stmt
, tree
*type_in
, tree
*type_out
)
579 stmt_vec_info stmt_vinfo
= vinfo_for_stmt (last_stmt
);
580 tree type
, half_type
;
582 loop_vec_info loop_info
= STMT_VINFO_LOOP_VINFO (stmt_vinfo
);
583 struct loop
*loop
= LOOP_VINFO_LOOP (loop_info
);
586 if (!is_gimple_assign (last_stmt
))
589 type
= gimple_expr_type (last_stmt
);
591 /* Look for the following pattern
594 In which DX is at least double the size of X, and sum_1 has been
595 recognized as a reduction variable.
598 /* Starting from LAST_STMT, follow the defs of its uses in search
599 of the above pattern. */
601 if (gimple_assign_rhs_code (last_stmt
) != PLUS_EXPR
)
604 if (STMT_VINFO_DEF_TYPE (stmt_vinfo
) != vect_reduction_def
)
607 oprnd0
= gimple_assign_rhs1 (last_stmt
);
608 oprnd1
= gimple_assign_rhs2 (last_stmt
);
609 if (TYPE_MAIN_VARIANT (TREE_TYPE (oprnd0
)) != TYPE_MAIN_VARIANT (type
)
610 || TYPE_MAIN_VARIANT (TREE_TYPE (oprnd1
)) != TYPE_MAIN_VARIANT (type
))
613 /* So far so good. Since last_stmt was detected as a (summation) reduction,
614 we know that oprnd1 is the reduction variable (defined by a loop-header
615 phi), and oprnd0 is an ssa-name defined by a stmt in the loop body.
616 Left to check that oprnd0 is defined by a cast from type 'type' to type
619 if (!widened_name_p (oprnd0
, last_stmt
, &half_type
, &stmt
))
622 oprnd0
= gimple_assign_rhs1 (stmt
);
623 *type_in
= half_type
;
626 /* Pattern detected. Create a stmt to be used to replace the pattern: */
627 var
= vect_recog_temp_ssa_var (type
, NULL
);
628 pattern_stmt
= gimple_build_assign_with_ops (WIDEN_SUM_EXPR
, var
,
630 SSA_NAME_DEF_STMT (var
) = pattern_stmt
;
632 if (vect_print_dump_info (REPORT_DETAILS
))
634 fprintf (vect_dump
, "vect_recog_widen_sum_pattern: detected: ");
635 print_gimple_stmt (vect_dump
, pattern_stmt
, 0, TDF_SLIM
);
638 /* We don't allow changing the order of the computation in the inner-loop
639 when doing outer-loop vectorization. */
640 if (nested_in_vect_loop_p (loop
, last_stmt
))
642 if (vect_print_dump_info (REPORT_DETAILS
))
643 fprintf (vect_dump
, "vect_recog_widen_sum_pattern: not allowed.");
651 /* Function vect_pattern_recog_1
654 PATTERN_RECOG_FUNC: A pointer to a function that detects a certain
656 STMT: A stmt from which the pattern search should start.
658 If PATTERN_RECOG_FUNC successfully detected the pattern, it creates an
659 expression that computes the same functionality and can be used to
660 replace the sequence of stmts that are involved in the pattern.
663 This function checks if the expression returned by PATTERN_RECOG_FUNC is
664 supported in vector form by the target. We use 'TYPE_IN' to obtain the
665 relevant vector type. If 'TYPE_IN' is already a vector type, then this
666 indicates that target support had already been checked by PATTERN_RECOG_FUNC.
667 If 'TYPE_OUT' is also returned by PATTERN_RECOG_FUNC, we check that it fits
668 to the available target pattern.
670 This function also does some bookkeeping, as explained in the documentation
671 for vect_recog_pattern. */
674 vect_pattern_recog_1 (
675 gimple (* vect_recog_func
) (gimple
, tree
*, tree
*),
676 gimple_stmt_iterator si
)
678 gimple stmt
= gsi_stmt (si
), pattern_stmt
;
679 stmt_vec_info stmt_info
= vinfo_for_stmt (stmt
);
680 stmt_vec_info pattern_stmt_info
;
681 loop_vec_info loop_vinfo
= STMT_VINFO_LOOP_VINFO (stmt_info
);
682 tree pattern_vectype
;
683 tree type_in
, type_out
;
686 pattern_stmt
= (* vect_recog_func
) (stmt
, &type_in
, &type_out
);
690 if (VECTOR_MODE_P (TYPE_MODE (type_in
)))
692 /* No need to check target support (already checked by the pattern
693 recognition function). */
694 pattern_vectype
= type_in
;
698 enum machine_mode vec_mode
;
699 enum insn_code icode
;
702 /* Check target support */
703 pattern_vectype
= get_vectype_for_scalar_type (type_in
);
704 if (!pattern_vectype
)
707 if (is_gimple_assign (pattern_stmt
))
708 code
= gimple_assign_rhs_code (pattern_stmt
);
711 gcc_assert (is_gimple_call (pattern_stmt
));
715 optab
= optab_for_tree_code (code
, pattern_vectype
, optab_default
);
716 vec_mode
= TYPE_MODE (pattern_vectype
);
718 || (icode
= optab_handler (optab
, vec_mode
)->insn_code
) ==
721 && (!get_vectype_for_scalar_type (type_out
)
722 || (insn_data
[icode
].operand
[0].mode
!=
723 TYPE_MODE (get_vectype_for_scalar_type (type_out
))))))
727 /* Found a vectorizable pattern. */
728 if (vect_print_dump_info (REPORT_DETAILS
))
730 fprintf (vect_dump
, "pattern recognized: ");
731 print_gimple_stmt (vect_dump
, pattern_stmt
, 0, TDF_SLIM
);
734 /* Mark the stmts that are involved in the pattern. */
735 gsi_insert_before (&si
, pattern_stmt
, GSI_SAME_STMT
);
736 set_vinfo_for_stmt (pattern_stmt
,
737 new_stmt_vec_info (pattern_stmt
, loop_vinfo
));
738 pattern_stmt_info
= vinfo_for_stmt (pattern_stmt
);
740 STMT_VINFO_RELATED_STMT (pattern_stmt_info
) = stmt
;
741 STMT_VINFO_DEF_TYPE (pattern_stmt_info
) = STMT_VINFO_DEF_TYPE (stmt_info
);
742 STMT_VINFO_VECTYPE (pattern_stmt_info
) = pattern_vectype
;
743 STMT_VINFO_IN_PATTERN_P (stmt_info
) = true;
744 STMT_VINFO_RELATED_STMT (stmt_info
) = pattern_stmt
;
750 /* Function vect_pattern_recog
753 LOOP_VINFO - a struct_loop_info of a loop in which we want to look for
756 Output - for each computation idiom that is detected we insert a new stmt
757 that provides the same functionality and that can be vectorized. We
758 also record some information in the struct_stmt_info of the relevant
759 stmts, as explained below:
761 At the entry to this function we have the following stmts, with the
762 following initial value in the STMT_VINFO fields:
764 stmt in_pattern_p related_stmt vec_stmt
766 S2: a_2 = ..use(a_i).. - - -
767 S3: a_1 = ..use(a_2).. - - -
768 S4: a_0 = ..use(a_1).. - - -
769 S5: ... = ..use(a_0).. - - -
771 Say the sequence {S1,S2,S3,S4} was detected as a pattern that can be
772 represented by a single stmt. We then:
773 - create a new stmt S6 that will replace the pattern.
774 - insert the new stmt S6 before the last stmt in the pattern
775 - fill in the STMT_VINFO fields as follows:
777 in_pattern_p related_stmt vec_stmt
779 S2: a_2 = ..use(a_i).. - - -
780 S3: a_1 = ..use(a_2).. - - -
781 > S6: a_new = .... - S4 -
782 S4: a_0 = ..use(a_1).. true S6 -
783 S5: ... = ..use(a_0).. - - -
785 (the last stmt in the pattern (S4) and the new pattern stmt (S6) point
786 to each other through the RELATED_STMT field).
788 S6 will be marked as relevant in vect_mark_stmts_to_be_vectorized instead
789 of S4 because it will replace all its uses. Stmts {S1,S2,S3} will
790 remain irrelevant unless used by stmts other than S4.
792 If vectorization succeeds, vect_transform_stmt will skip over {S1,S2,S3}
793 (because they are marked as irrelevant). It will vectorize S6, and record
794 a pointer to the new vector stmt VS6 both from S6 (as usual), and also
795 from S4. We do that so that when we get to vectorizing stmts that use the
796 def of S4 (like S5 that uses a_0), we'll know where to take the relevant
797 vector-def from. S4 will be skipped, and S5 will be vectorized as usual:
799 in_pattern_p related_stmt vec_stmt
801 S2: a_2 = ..use(a_i).. - - -
802 S3: a_1 = ..use(a_2).. - - -
803 > VS6: va_new = .... - - -
804 S6: a_new = .... - S4 VS6
805 S4: a_0 = ..use(a_1).. true S6 VS6
806 > VS5: ... = ..vuse(va_new).. - - -
807 S5: ... = ..use(a_0).. - - -
809 DCE could then get rid of {S1,S2,S3,S4,S5,S6} (if their defs are not used
810 elsewhere), and we'll end up with:
813 VS5: ... = ..vuse(va_new)..
815 If vectorization does not succeed, DCE will clean S6 away (its def is
816 not used), and we'll end up with the original sequence.
820 vect_pattern_recog (loop_vec_info loop_vinfo
)
822 struct loop
*loop
= LOOP_VINFO_LOOP (loop_vinfo
);
823 basic_block
*bbs
= LOOP_VINFO_BBS (loop_vinfo
);
824 unsigned int nbbs
= loop
->num_nodes
;
825 gimple_stmt_iterator si
;
828 gimple (* vect_recog_func_ptr
) (gimple
, tree
*, tree
*);
830 if (vect_print_dump_info (REPORT_DETAILS
))
831 fprintf (vect_dump
, "=== vect_pattern_recog ===");
833 /* Scan through the loop stmts, applying the pattern recognition
834 functions starting at each stmt visited: */
835 for (i
= 0; i
< nbbs
; i
++)
837 basic_block bb
= bbs
[i
];
838 for (si
= gsi_start_bb (bb
); !gsi_end_p (si
); gsi_next (&si
))
840 stmt
= gsi_stmt (si
);
842 /* Scan over all generic vect_recog_xxx_pattern functions. */
843 for (j
= 0; j
< NUM_PATTERNS
; j
++)
845 vect_recog_func_ptr
= vect_vect_recog_func_ptrs
[j
];
846 vect_pattern_recog_1 (vect_recog_func_ptr
, si
);