The following adjusts the SLP build for only-live stmts to not
only consider vect_induction_def and vect_internal_def that are
not part of a reduction but instead consider all non-reduction
defs that are not part of a reduction, specifically in this case
a recurrence def. This is also a missed optimization on the
gcc-15 branch (but IMO a very minor one).
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/121686
* tree-vect-slp.cc (vect_analyze_slp): Consider all only-live
non-reduction defs for discovery.
* gcc.dg/vect/pr121686.c: New testcase.
---
gcc/testsuite/gcc.dg/vect/pr121686.c | 32 ++++++++++++++++++++++++++++
gcc/tree-vect-slp.cc | 5 ++---
2 files changed, 34 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/vect/pr121686.c
diff --git a/gcc/testsuite/gcc.dg/vect/pr121686.c
b/gcc/testsuite/gcc.dg/vect/pr121686.c
new file mode 100644
index 00000000000..5a9284c3d31
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr121686.c
@@ -0,0 +1,32 @@
+/* { dg-additional-options "-O3" } */
+
+#include "tree-vect.h"
+
+signed char a, b, c, f;
+int d, e, g, h;
+
+int main()
+{
+ int j, k;
+ signed char m;
+ check_vect ();
+ while (f < 4) {
+ k = b = 3;
+ for (; b >= 0; b--) {
+ j = a < 0 ? a : a >> h;
+ g = k;
+ e = j;
+ k = 0;
+ while (1) {
+ if (j)
+ break;
+ k = f == 0;
+ break;
+ }
+ }
+ m = g * 87;
+ if (m < 70)
+ __builtin_abort();
+ return 0;
+ }
+}
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 2df9d2b3c6d..86508e22f49 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -5312,9 +5312,8 @@ vect_analyze_slp (vec_info *vinfo, unsigned max_tree_size,
&& ((stmt_info = vect_stmt_to_vectorize (stmt_info)), true)
&& STMT_VINFO_RELEVANT (stmt_info) == vect_used_only_live
&& STMT_VINFO_LIVE_P (stmt_info)
- && (STMT_VINFO_DEF_TYPE (stmt_info) == vect_induction_def
- || (STMT_VINFO_DEF_TYPE (stmt_info) == vect_internal_def
- && STMT_VINFO_REDUC_IDX (stmt_info) == -1)))
+ && !VECTORIZABLE_CYCLE_DEF (STMT_VINFO_DEF_TYPE (stmt_info))
+ && STMT_VINFO_REDUC_IDX (stmt_info) == -1)
{
vec<stmt_vec_info> stmts;
vec<stmt_vec_info> roots = vNULL;
--
2.43.0
