According to
https://gcc.gnu.org/pipermail/gcc/2020-November/234344.html, GCC is
allowed to perform optimizations that remove floating point traps,
since they do not affect the modeled control flow. This interferes with
two signaling comparison tests, where (a <= b && a >= b) is turned into
(a <= b && a == b) by test_for_singularity, into ((a <= b) & (a == b))
by vectorizer and then into (a == b) eliminate_redundant_comparison.
Fix by making traps affect the control flow by turning them into
exceptions.
gcc/testsuite/ChangeLog:
2020-12-03 Ilya Leoshkevich <i...@linux.ibm.com>
* gcc.target/s390/zvector/autovec-double-signaling-eq.c: Build
with exceptions.
* gcc.target/s390/zvector/autovec-float-signaling-eq.c:
Likewise.
---
.../gcc.target/s390/zvector/autovec-double-signaling-eq.c | 2 +-
.../gcc.target/s390/zvector/autovec-float-signaling-eq.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git
a/gcc/testsuite/gcc.target/s390/zvector/autovec-double-signaling-eq.c
b/gcc/testsuite/gcc.target/s390/zvector/autovec-double-signaling-eq.c
index a8402b9f705..3645d3cc393 100644
--- a/gcc/testsuite/gcc.target/s390/zvector/autovec-double-signaling-eq.c
+++ b/gcc/testsuite/gcc.target/s390/zvector/autovec-double-signaling-eq.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O3 -march=z14 -mzvector -mzarch" } */
+/* { dg-options "-O3 -march=z14 -mzvector -mzarch -fexceptions
-fnon-call-exceptions" } */
#include "autovec.h"
diff --git a/gcc/testsuite/gcc.target/s390/zvector/autovec-float-signaling-eq.c
b/gcc/testsuite/gcc.target/s390/zvector/autovec-float-signaling-eq.c
index 7dd91a5e6f3..d98aa0c494e 100644
--- a/gcc/testsuite/gcc.target/s390/zvector/autovec-float-signaling-eq.c
+++ b/gcc/testsuite/gcc.target/s390/zvector/autovec-float-signaling-eq.c
@@ -1,5 +1,5 @@
/* { dg-do compile } */
-/* { dg-options "-O3 -march=z14 -mzvector -mzarch" } */
+/* { dg-options "-O3 -march=z14 -mzvector -mzarch -fexceptions
-fnon-call-exceptions" } */
#include "autovec.h"
--
2.25.4
