I missed that indeed SLP permutation code generation can end up
refering to a non-last vectorized stmt in the last SLP_TREE_VEC_STMTS
element as optimization. So walk them all.
Bootstrapped / tested on x86_64-unknown-linux-gnu, pushed.
2020-06-19 Richard Biener <rguent...@suse.de>
PR tree-optimization/95761
* tree-vect-slp.c (vect_schedule_slp_instance): Walk all
vectorized stmts for finding the last one.
* gcc.dg/torture/pr95761.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr95761.c | 25 +++++++++++++++++++++++++
gcc/tree-vect-slp.c | 15 +++++++++------
2 files changed, 34 insertions(+), 6 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr95761.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr95761.c
b/gcc/testsuite/gcc.dg/torture/pr95761.c
new file mode 100644
index 00000000000..65ee0fc1c11
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr95761.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+
+typedef int a[10];
+typedef struct {
+ a b;
+ a c;
+ a d;
+ a e;
+} f;
+f g;
+int *j;
+void k() {
+ for (;;) {
+ a l;
+ j[0] = g.b[0];
+ int *h = g.d;
+ int i = 0;
+ for (; i < 10; i++)
+ h[i] = l[0] - g.e[0];
+ h = g.e;
+ i = 0;
+ for (; i < 10; i++)
+ h[i] = l[1] + g.e[i];
+ }
+}
diff --git a/gcc/tree-vect-slp.c b/gcc/tree-vect-slp.c
index e33b42fbc68..c9ec77b4a97 100644
--- a/gcc/tree-vect-slp.c
+++ b/gcc/tree-vect-slp.c
@@ -4207,7 +4207,6 @@ vect_schedule_slp_instance (vec_info *vinfo,
{
/* Or if we do not have 1:1 matching scalar stmts emit after the
children vectorized defs. */
- gimple *last_in_child;
gimple *last_stmt = NULL;
FOR_EACH_VEC_ELT (SLP_TREE_CHILDREN (node), i, child)
/* ??? With only external defs the following breaks. Note
@@ -4216,11 +4215,15 @@ vect_schedule_slp_instance (vec_info *vinfo,
if (SLP_TREE_DEF_TYPE (child) == vect_internal_def)
{
/* We are emitting all vectorized stmts in the same place and
- the last one is the last. */
- last_in_child = SLP_TREE_VEC_STMTS (child).last ();
- if (!last_stmt
- || vect_stmt_dominates_stmt_p (last_stmt, last_in_child))
- last_stmt = last_in_child;
+ the last one is the last.
+ ??? Unless we have a load permutation applied and that
+ figures to re-use an earlier generated load. */
+ unsigned j;
+ gimple *vstmt;
+ FOR_EACH_VEC_ELT (SLP_TREE_VEC_STMTS (child), j, vstmt)
+ if (!last_stmt
+ || vect_stmt_dominates_stmt_p (last_stmt, vstmt))
+ last_stmt = vstmt;
}
if (is_a <gphi *> (last_stmt))
si = gsi_after_labels (gimple_bb (last_stmt));
--
2.26.2
