When following the definitions of SSA names, some recognisers
already cope with statements that have been replaced by patterns.
This patch makes that happen automatically for users of
type_conversion_p and vect_get_internal_def. It also adds
a vect_look_through_pattern helper that can be used directly.
The reason for doing this is that the main patch for PR85694
makes over_widening handle more general cases. These over-widened
patterns can still be useful when matching later statements;
e.g. an overwidened MULT_EXPR could be the input to a DOT_PROD_EXPR.
The patch doesn't do anything with the STMT_VINFO_IN_PATTERN_P checks
in vect_recog_over_widening_pattern or vect_recog_widen_shift_pattern
since later patches rewrite them anyway.
Doing this fixed an XFAIL in vect-reduc-dot-u16b.c.
Tested on aarch64-linux-gnu and x86_64-linux-gnu. OK to install?
Richard
2018-06-18 Richard Sandiford <richard.sandif...@arm.com>
gcc/
* tree-vectorizer.h (vect_look_through_pattern): New function.
* tree-vect-patterns.c (vect_get_internal_def): Use it.
(type_conversion_p): Likewise.
(vect_recog_rotate_pattern): Likewise.
(vect_recog_dot_prod_pattern): Check directly for a WIDEN_MULT_EXPR.
(vect_recog_vector_vector_shift_pattern): Don't check
STMT_VINFO_IN_PATTERN_P.
gcc/testsuite/
* gcc.dg/vect/vect-reduc-dot-u16b.c: Remove xfail and update the
test for vectorization along the lines described in the comment.
Index: gcc/tree-vectorizer.h
===================================================================
--- gcc/tree-vectorizer.h 2018-06-18 15:43:52.951038712 +0100
+++ gcc/tree-vectorizer.h 2018-06-18 15:44:05.522927566 +0100
@@ -1422,6 +1422,19 @@ vect_get_scalar_dr_size (struct data_ref
return tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (DR_REF (dr))));
}
+/* STMT is a statement that we're thinking about vectorizing.
+ If it has been replaced by a pattern statement, return that
+ pattern statement, otherwise return STMT itself. */
+
+inline gimple *
+vect_look_through_pattern (gimple *stmt)
+{
+ stmt_vec_info vinfo = vinfo_for_stmt (stmt);
+ if (STMT_VINFO_IN_PATTERN_P (vinfo))
+ stmt = STMT_VINFO_RELATED_STMT (vinfo);
+ return stmt;
+}
+
/* Source location */
extern source_location vect_location;
Index: gcc/tree-vect-patterns.c
===================================================================
--- gcc/tree-vect-patterns.c 2018-06-18 15:43:52.951038712 +0100
+++ gcc/tree-vect-patterns.c 2018-06-18 15:44:05.522927566 +0100
@@ -164,7 +164,7 @@ vect_get_internal_def (vec_info *vinfo,
|| dt != vect_internal_def)
return NULL;
- return vinfo_for_stmt (def_stmt);
+ return vinfo_for_stmt (vect_look_through_pattern (def_stmt));
}
/* Check whether NAME, an ssa-name used in USE_STMT,
@@ -195,12 +195,7 @@ type_conversion_p (tree name, gimple *us
return false;
if (dt == vect_internal_def)
- {
- stmt_vec_info def_vinfo = vinfo_for_stmt (*def_stmt);
- if (STMT_VINFO_IN_PATTERN_P (def_vinfo))
- return false;
- }
-
+ *def_stmt = vect_look_through_pattern (*def_stmt);
if (!is_gimple_assign (*def_stmt))
return false;
@@ -384,20 +379,11 @@ vect_recog_dot_prod_pattern (vec<gimple
/* FORNOW. Can continue analyzing the def-use chain when this stmt in a phi
inside the loop (in case we are analyzing an outer-loop). */
gassign *mult = dyn_cast <gassign *> (mult_vinfo->stmt);
- if (!mult || gimple_assign_rhs_code (mult) != MULT_EXPR)
+ if (!mult)
return NULL;
- if (STMT_VINFO_IN_PATTERN_P (mult_vinfo))
+ if (gimple_assign_rhs_code (mult) == WIDEN_MULT_EXPR)
{
/* Has been detected as a widening multiplication? */
-
- mult = dyn_cast <gassign *> (STMT_VINFO_RELATED_STMT (mult_vinfo));
- if (!mult || gimple_assign_rhs_code (mult) != WIDEN_MULT_EXPR)
- return NULL;
- STMT_VINFO_PATTERN_DEF_SEQ (stmt_vinfo)
- = STMT_VINFO_PATTERN_DEF_SEQ (mult_vinfo);
- mult_vinfo = vinfo_for_stmt (mult);
- gcc_assert (mult_vinfo);
- gcc_assert (STMT_VINFO_DEF_TYPE (mult_vinfo) == vect_internal_def);
oprnd00 = gimple_assign_rhs1 (mult);
oprnd01 = gimple_assign_rhs2 (mult);
}
@@ -407,6 +393,9 @@ vect_recog_dot_prod_pattern (vec<gimple
gimple *def_stmt;
tree oprnd0, oprnd1;
+ if (gimple_assign_rhs_code (mult) != MULT_EXPR)
+ return NULL;
+
oprnd0 = gimple_assign_rhs1 (mult);
oprnd1 = gimple_assign_rhs2 (mult);
if (!type_conversion_p (oprnd0, mult, true, &half_type0, &def_stmt,
@@ -1803,6 +1792,9 @@ vect_recog_rotate_pattern (vec<gimple *>
&& dt != vect_external_def)
return NULL;
+ if (dt == vect_internal_def)
+ def_stmt = vect_look_through_pattern (def_stmt);
+
vectype = get_vectype_for_scalar_type (type);
if (vectype == NULL_TREE)
return NULL;
@@ -2051,9 +2043,7 @@ vect_recog_vector_vector_shift_pattern (
tree def = NULL_TREE;
gassign *def_stmt = dyn_cast <gassign *> (def_vinfo->stmt);
- if (!STMT_VINFO_IN_PATTERN_P (def_vinfo)
- && def_stmt
- && gimple_assign_cast_p (def_stmt))
+ if (def_stmt && gimple_assign_cast_p (def_stmt))
{
tree rhs1 = gimple_assign_rhs1 (def_stmt);
if (TYPE_MODE (TREE_TYPE (rhs1)) == TYPE_MODE (TREE_TYPE (oprnd0))
Index: gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16b.c
===================================================================
--- gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16b.c 2016-11-11
17:07:36.588798042 +0000
+++ gcc/testsuite/gcc.dg/vect/vect-reduc-dot-u16b.c 2018-06-18
15:44:05.522927566 +0100
@@ -10,11 +10,8 @@ #define DOT2 43680
unsigned short X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
unsigned short Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__)));
-/* short->int->int dot product.
- Currently not detected as a dot-product pattern: the multiplication
- promotes the ushorts to int, and then the product is promoted to unsigned
- int for the addition. Which results in an int->unsigned int cast, which
- since no bits are modified in the cast should be trivially vectorizable. */
+/* ushort->int->uint dot product: the multiplication promotes the ushorts
+ to int, and then the product is converted to uint for the addition. */
__attribute__ ((noinline)) unsigned int
foo2(int len) {
int i;
@@ -47,12 +44,6 @@ int main (void)
return 0;
}
-/* { dg-final { scan-tree-dump-times "vect_recog_dot_prod_pattern: detected" 1
"vect" { xfail *-*-* } } } */
-
-/* Once the dot-product pattern is detected, we expect
- that loop to be vectorized on vect_udot_hi targets (targets that support
- dot-product of unsigned shorts) and targets that support widening
multiplication. */
-/* The induction loop in main is vectorized. */
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 2 "vect" { xfail
*-*-* } } } */
-/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target
vect_pack_trunc } } } */
+/* { dg-final { scan-tree-dump-times "vect_recog_dot_prod_pattern: detected" 1
"vect" } } */
+/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" { target {
vect_pack_trunc || vect_udot_hi } } } } */
