diff mbox series

tree-optimization/111082 - bogus promoted min

Message ID 20230821094834.34B663836E92@sourceware.org
State Unresolved
Headers
Series tree-optimization/111082 - bogus promoted min |

Checks

Context Check Description
snail/gcc-patch-check warning Git am fail log

Commit Message

Richard Biener Aug. 21, 2023, 9:47 a.m. UTC 
  vectorize_slp_instance_root_stmt promotes operations with undefined
overflow to unsigned arithmetic but fails to consider operations
that do not overflow like MIN which it turned into MIN with wrong
signedness and in the case of the PR an unsupported operation.
The following rectifies this.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

	PR tree-optimization/111082
	* tree-vect-slp.cc (vectorize_slp_instance_root_stmt): Only
	pun operations that can overflow.

	* gcc.dg/pr111082.c: New testcase.
---
 gcc/testsuite/gcc.dg/pr111082.c | 10 ++++++++++
 gcc/tree-vect-slp.cc            |  3 ++-
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/pr111082.c
diff mbox series

Patch

diff --git a/gcc/testsuite/gcc.dg/pr111082.c b/gcc/testsuite/gcc.dg/pr111082.c
new file mode 100644
index 00000000000..46e36e320d1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr111082.c
@@ -0,0 +1,10 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O3 -fno-vect-cost-model" } */
+/* { dg-additional-options "-mavx512f" { target { x86_64-*-* i?86-*-* } } } */
+
+long minarray2(const long *input)
+{
+  if (input[0] < input[1])
+    return input[0] ;
+  return input[1];
+}
diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc
index 51f3466805c..e8484401bc9 100644
--- a/gcc/tree-vect-slp.cc
+++ b/gcc/tree-vect-slp.cc
@@ -9180,7 +9180,8 @@  vectorize_slp_instance_root_stmt (slp_tree node, slp_instance instance)
       tree vectype = TREE_TYPE (vec_def);
       tree compute_vectype = vectype;
       bool pun_for_overflow_p = (ANY_INTEGRAL_TYPE_P (vectype)
-				 && TYPE_OVERFLOW_UNDEFINED (vectype));
+				 && TYPE_OVERFLOW_UNDEFINED (vectype)
+				 && operation_can_overflow (reduc_code));
       if (pun_for_overflow_p)
 	{
 	  compute_vectype = unsigned_type_for (vectype);