When we swap operands for SLP builds we lose track where exactly
pattern defs are - but we fail to update the any_pattern member
of the operands info. Do so conservatively.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
2021-08-25 Richard Biener <rguent...@suse.de>
PR tree-optimization/102046
* tree-vect-slp.c (vect_build_slp_tree_2): Conservatively
update ->any_pattern when swapping operands.
* gcc.dg/vect/pr102046.c: New testcase.
---
gcc/testsuite/gcc.dg/vect/pr102046.c | 19 +++++++++++++++++++
gcc/tree-vect-slp.c | 4 ++++
2 files changed, 23 insertions(+)
create mode 100644 gcc/testsuite/gcc.dg/vect/pr102046.c
diff --git a/gcc/testsuite/gcc.dg/vect/pr102046.c
b/gcc/testsuite/gcc.dg/vect/pr102046.c
new file mode 100644
index 00000000000..ae48b497dc0
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr102046.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-O3 -fvect-cost-model=dynamic" } */
+/* { dg-additional-options "-march=btver2" { target x86_64-*-* i?86-*-* } } */
+
+struct S
+{
+ unsigned a, b;
+};
+
+struct S g;
+
+void
+foo (struct S *o)
+{
+ struct S s = g;
+ s.b *= 3;
+ s.a -= s.a / 2;
+ *o = s;
+}
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index edc11c62793..4d688c7a267 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -2311,6 +2311,10 @@ out:
}
if (dump_enabled_p ())
dump_printf (MSG_NOTE, "\n");
+ /* After swapping some operands we lost track whether an
+ operand has any pattern defs so be conservative here. */
+ if (oprnds_info[0]->any_pattern || oprnds_info[1]->any_pattern)
+ oprnds_info[0]->any_pattern = oprnds_info[1]->any_pattern = true;
/* And try again with scratch 'matches' ... */
bool *tem = XALLOCAVEC (bool, group_size);
if ((child = vect_build_slp_tree (vinfo, oprnd_info->def_stmts,
--
2.31.1
