This optimisation does not honour signed zeros, so should not be
enabled except with -fno-signed-zeros.
OK for master? I do not have commit rights for GCC, so if the patch
is fine would someone be able to commit for me? The bug is present
in all GCC versions from 12.1.0 onwards - is it possible to backport
this?
Bootstrapped Regtested on aarch64-none-linux-gnu and no issues.
Thanks,
Joe
gcc/ChangeLog:
* match.pd: Fix truncation pattern for -fno-signed-zeroes
gcc/testsuite/ChangeLog:
* gcc.target/aarch64/no_merge_trunc_signed_zero.c: New test.
---
gcc/match.pd | 2 +-
.../aarch64/no_merge_trunc_signed_zero.c | 24 +++++++++++++++++++
2 files changed, 25 insertions(+), 1 deletion(-)
create mode 100644
gcc/testsuite/gcc.target/aarch64/no_merge_trunc_signed_zero.c
diff --git a/gcc/match.pd b/gcc/match.pd
index 9ce313323a3..45c34c810cf 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -4857,7 +4857,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
#if GIMPLE
(simplify
(float (fix_trunc @0))
- (if (!flag_trapping_math
+ (if (!flag_trapping_math && !HONOR_SIGNED_ZEROS(type)
&& types_match (type, TREE_TYPE (@0))
&& direct_internal_fn_supported_p (IFN_TRUNC, type,
OPTIMIZE_FOR_BOTH))
diff --git a/gcc/testsuite/gcc.target/aarch64/no_merge_trunc_signed_zero.c
b/gcc/testsuite/gcc.target/aarch64/no_merge_trunc_signed_zero.c
new file mode 100644
index 00000000000..b2c93e55567
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/no_merge_trunc_signed_zero.c
@@ -0,0 +1,24 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-trapping-math -fsigned-zeros" } */
+
+#include <math.h>
+
+float
+f1 (float x)
+{
+ return (int) rintf(x);
+}
+
+double
+f2 (double x)
+{
+ return (long) rint(x);
+}
+
+/* { dg-final { scan-assembler "frintx\\ts\[0-9\]+, s\[0-9\]+" } } */
+/* { dg-final { scan-assembler "cvtzs\\ts\[0-9\]+, s\[0-9\]+" } } */
+/* { dg-final { scan-assembler "scvtf\\ts\[0-9\]+, s\[0-9\]+" } } */
+/* { dg-final { scan-assembler "frintx\\td\[0-9\]+, d\[0-9\]+" } } */
+/* { dg-final { scan-assembler "cvtzs\\td\[0-9\]+, d\[0-9\]+" } } */
+/* { dg-final { scan-assembler "scvtf\\td\[0-9\]+, d\[0-9\]+" } } */
+
--
2.27.0
