https://gcc.gnu.org/g:df87b300bd13ed047b1159022c93445f130458e6
commit r15-8037-gdf87b300bd13ed047b1159022c93445f130458e6
Author: Richard Sandiford <richard.sandif...@arm.com>
Date: Thu Mar 13 15:13:00 2025 +0000
testsuite: Fix sve/mask_struct_load_3_run.c [PR113965]
Among other things, this testcase tests an addition of the four
values (n*4+[0:3])*9//2 for each n in [0:99]. The addition is
done in multiple integer and floating-point types and the test
is compiled with -ffast-math.
One of the floating-point types is _Float16, and as Andrew says
in the PR, _Float16's limited precision means that the order of the
additions begins to matter for higher n. Specifically, some orders
begin to give different results from others at n=38, and at many
higher n as well.
This patch uses 5/3 rather than 9/2. I tested locally that
all addition orders give the same result over the test range.
gcc/testsuite/
PR testsuite/113965
* gcc.target/aarch64/sve/mask_struct_load_3_run.c: Use an
input range that is suitable for _Float16.
Diff:
---
gcc/testsuite/gcc.target/aarch64/sve/mask_struct_load_3_run.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/testsuite/gcc.target/aarch64/sve/mask_struct_load_3_run.c
b/gcc/testsuite/gcc.target/aarch64/sve/mask_struct_load_3_run.c
index 8bc3b08fcf4d..c0a7416cfafc 100644
--- a/gcc/testsuite/gcc.target/aarch64/sve/mask_struct_load_3_run.c
+++ b/gcc/testsuite/gcc.target/aarch64/sve/mask_struct_load_3_run.c
@@ -18,7 +18,7 @@
asm volatile ("" ::: "memory"); \
} \
for (int i = 0; i < N * 4; ++i) \
- in[i] = i * 9 / 2; \
+ in[i] = i * 5 / 3; \
NAME##_4 (out, in, mask, N); \
for (int i = 0; i < N; ++i) \
{ \
