The check was implemented incorrectly, so vec_widen_smult_{even,odd}_M
was never used. This is not good for targets with native even/odd
widening multiplication but not lo/hi multiplication.
The fix is actually developed by Richard Biener.
gcc/ChangeLog:
PR tree-optimization/116142
* tree-vect-stmts.cc (supportable_widening_operation): Remove an
redundant and incorrect vect_reduction_def check, and fix the
operand of another vect_reduction_def check.
gcc/testsuite/ChangeLog:
PR tree-optimization/116142
* gcc.target/i386/pr116142.c: New test.
---
Bootstrapped and regtested on x86_64-linux-gnu. Ok for trunk?
gcc/testsuite/gcc.target/i386/pr116142.c | 18 ++++++++++++++++++
gcc/tree-vect-stmts.cc | 3 +--
2 files changed, 19 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr116142.c
diff --git a/gcc/testsuite/gcc.target/i386/pr116142.c
b/gcc/testsuite/gcc.target/i386/pr116142.c
new file mode 100644
index 00000000000..d288a50b237
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr116142.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mavx512f -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump "WIDEN_MULT_EVEN_EXPR" "optimized" } } */
+/* { dg-final { scan-tree-dump "WIDEN_MULT_ODD_EXPR" "optimized" } } */
+
+typedef __INT32_TYPE__ i32;
+typedef __INT64_TYPE__ i64;
+
+i32 x[16], y[16];
+
+i64
+test (void)
+{
+ i64 ret = 0;
+ for (int i = 0; i < 16; i++)
+ ret ^= (i64) x[i] * y[i];
+ return ret;
+}
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 20cae83e820..385e63163c2 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -14179,7 +14179,6 @@ supportable_widening_operation (vec_info *vinfo,
are properly set up for the caller. If we fail, we'll continue with
a VEC_WIDEN_MULT_LO/HI_EXPR check. */
if (vect_loop
- && STMT_VINFO_RELEVANT (stmt_info) == vect_used_by_reduction
&& !nested_in_vect_loop_p (vect_loop, stmt_info)
&& supportable_widening_operation (vinfo, VEC_WIDEN_MULT_EVEN_EXPR,
stmt_info, vectype_out,
@@ -14192,7 +14191,7 @@ supportable_widening_operation (vec_info *vinfo,
same operation. One such an example is s += a * b, where elements
in a and b cannot be reordered. Here we check if the vector
defined
by STMT is only directly used in the reduction statement. */
- tree lhs = gimple_assign_lhs (stmt_info->stmt);
+ tree lhs = gimple_assign_lhs (vect_orig_stmt (stmt_info)->stmt);
stmt_vec_info use_stmt_info = loop_info->lookup_single_use (lhs);
if (use_stmt_info
&& STMT_VINFO_DEF_TYPE (use_stmt_info) == vect_reduction_def)
--
2.46.0
