From d11bcbe166c03f722c0e0d41d6e87ac445758fba Mon Sep 17 00:00:00 2001
From: Richard Biener <rguenther@suse.de>
Date: Wed, 7 Apr 2021 10:02:07 +0200
Subject: [PATCH] tree-optimization/99947 - avoid v.safe_push (v[0])
This avoids (again) the C++ pitfall of pushing a reference to
sth being reallocated.
2021-04-07 Richard Biener <rguenther@suse.de>
PR tree-optimization/99947
* tree-vect-loop.c (vectorizable_induction): Pre-allocate
steps vector to avoid pushing elements from the reallocated
vector.
* gcc.dg/torture/pr99947.c: New testcase.
---
gcc/testsuite/gcc.dg/torture/pr99947.c | 18 ++++++++++++++++++
gcc/tree-vect-loop.c | 3 ++-
2 files changed, 20 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/torture/pr99947.c
diff --git a/gcc/testsuite/gcc.dg/torture/pr99947.c b/gcc/testsuite/gcc.dg/torture/pr99947.c
new file mode 100644
index 000000000000..2cf3ec6aeb80
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr99947.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+
+int a, b, d, e;
+short c;
+void f() {
+ for (; e; e++) {
+ int g = 6;
+ for (; g > 2; g--) {
+ int i = -8;
+ while (i < 20) {
+ i += 5;
+ a += b;
+ }
+ c *= d;
+ }
+ b--;
+ }
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 4e928c65b317..93fa2928e001 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -8202,11 +8202,12 @@ vectorizable_induction (loop_vec_info loop_vinfo,
/* Fill up to the number of vectors we need for the whole group. */
nivs = least_common_multiple (group_size,
const_nunits) / const_nunits;
+ vec_steps.reserve (nivs-ivn);
for (; ivn < nivs; ++ivn)
{
SLP_TREE_VEC_STMTS (slp_node)
.quick_push (SLP_TREE_VEC_STMTS (slp_node)[0]);
- vec_steps.safe_push (vec_steps[0]);
+ vec_steps.quick_push (vec_steps[0]);
}
}
--
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