From 9890d4e8bcda1f34b8eefb481935ef0e4cd8069e Mon Sep 17 00:00:00 2001
From: Kewen Lin <linkw@linux.ibm.com>
Date: Wed, 26 Jul 2023 21:43:09 -0500
Subject: [PATCH] vect: Treat VMAT_ELEMENTWISE as scalar load in costing
[PR110776]
PR110776 exposes one issue that we could query unaligned
load for vector type but actually no unaligned vector load
is supported there. The reason is that the costed load is
with single-lane vector type and its memory access type is
VMAT_ELEMENTWISE, we actually take it as scalar load and
set its alignment_support_scheme as dr_unaligned_supported.
To avoid the ICE as exposed, following Rich's suggestion,
this patch is to make VMAT_ELEMENTWISE be costed as scalar
load.
Co-authored-by: Richard Biener <rguenther@suse.de>
PR tree-optimization/110776
gcc/ChangeLog:
* tree-vect-stmts.cc (vectorizable_load): Always cost VMAT_ELEMENTWISE
as scalar load.
gcc/testsuite/ChangeLog:
* gcc.target/powerpc/pr110776.c: New test.
---
gcc/testsuite/gcc.target/powerpc/pr110776.c | 22 +++++++++++++++++++++
gcc/tree-vect-stmts.cc | 5 ++++-
2 files changed, 26 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.target/powerpc/pr110776.c
diff --git a/gcc/testsuite/gcc.target/powerpc/pr110776.c b/gcc/testsuite/gcc.target/powerpc/pr110776.c
new file mode 100644
index 000000000000..749159fd6754
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr110776.c
@@ -0,0 +1,22 @@
+/* { dg-require-effective-target powerpc_altivec_ok } */
+/* { dg-options "-O2 -mdejagnu-cpu=power6 -maltivec" } */
+
+/* Verify there is no ICE. */
+
+int a;
+long *b;
+int
+c ()
+{
+ long e;
+ int d = 0;
+ for (long f; f; f++)
+ {
+ e = b[f * a];
+ if (e)
+ d = 1;
+ }
+ if (d)
+ for (;;)
+ ;
+}
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 5018bd23e6ec..6a4e8fce126a 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -9876,7 +9876,10 @@ vectorizable_load (vec_info *vinfo,
{
if (costing_p)
{
- if (VECTOR_TYPE_P (ltype))
+ /* For VMAT_ELEMENTWISE, just cost it as scalar_load to
+ avoid ICE, see PR110776. */
+ if (VECTOR_TYPE_P (ltype)
+ && memory_access_type != VMAT_ELEMENTWISE)
vect_get_load_cost (vinfo, stmt_info, 1,
alignment_support_scheme, misalignment,
false, &inside_cost, nullptr, cost_vec,
--
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