When we classify a conditional reduction chain as CONST_COND_REDUCTION
we fail to verify all involved conditionals have the same constant.
That's a quite unlikely situation so the following simply disables
such classification when there's more than one reduction statement.
Bootstrapped and tested on x86_64-unkown-linux-gnu, pushed.
Richard.
PR tree-optimization/114027
* tree-vect-loop.cc (vecctorizable_reduction): Use optimized
condition reduction classification only for single-element
chains.
* gcc.dg/vect/pr114027.c: New testcase.
---
gcc/testsuite/gcc.dg/vect/pr114027.c | 26 ++++++++++++++++++++++++++
gcc/tree-vect-loop.cc | 11 ++++++-----
2 files changed, 32 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/vect/pr114027.c
diff --git a/gcc/testsuite/gcc.dg/vect/pr114027.c
b/gcc/testsuite/gcc.dg/vect/pr114027.c
new file mode 100644
index 00000000000..ead9cdd982d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr114027.c
@@ -0,0 +1,26 @@
+#include "tree-vect.h"
+
+int __attribute__((noipa))
+foo (int *f, int n)
+{
+ int res = 0;
+ for (int i = 0; i < n; ++i)
+ {
+ if (f[2*i])
+ res = 2;
+ if (f[2*i+1])
+ res = -2;
+ }
+ return res;
+}
+
+int f[] = { 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 0 };
+
+int
+main ()
+{
+ if (foo (f, 16) != 2)
+ __builtin_abort ();
+ return 0;
+}
diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc
index 5a5865c42fc..35f1f8c7d42 100644
--- a/gcc/tree-vect-loop.cc
+++ b/gcc/tree-vect-loop.cc
@@ -7759,17 +7759,18 @@ vectorizable_reduction (loop_vec_info loop_vinfo,
< GET_MODE_SIZE (SCALAR_TYPE_MODE (TREE_TYPE
(vectype_op[i]))))))
vectype_in = vectype_op[i];
- if (op.code == COND_EXPR)
+ /* Record how the non-reduction-def value of COND_EXPR is defined.
+ ??? For a chain of multiple CONDs we'd have to match them up all. */
+ if (op.code == COND_EXPR && reduc_chain_length == 1)
{
- /* Record how the non-reduction-def value of COND_EXPR is defined. */
if (dt == vect_constant_def)
{
cond_reduc_dt = dt;
cond_reduc_val = op.ops[i];
}
- if (dt == vect_induction_def
- && def_stmt_info
- && is_nonwrapping_integer_induction (def_stmt_info, loop))
+ else if (dt == vect_induction_def
+ && def_stmt_info
+ && is_nonwrapping_integer_induction (def_stmt_info, loop))
{
cond_reduc_dt = dt;
cond_stmt_vinfo = def_stmt_info;
--
2.35.3
