https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123231
Bug ID: 123231
Summary: [Trunk] AArch64: Miscompile at -O2/O3
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: xxs_chy at outlook dot com
Target Milestone: ---
gcc version 16.0.0 20251218 (experimental) (crosstool-NG 1.28.0_rc1)
qemu-aarch64 version 10.1.2
Testcase:
#include <stdint.h>
#include <stdio.h>
#define BS_VEC(type, num) type __attribute__((vector_size(num * sizeof(type))))
uint64_t BS_CHECKSUM;
#define safe_mod_func_uint16_t_u_u(_ui1, _ui2)
\
({
\
uint16_t ui1;
\
uint16_t ui2 = _ui2;
\
ui2 ?: ui1 % ui2;
\
})
volatile int func_39_BS_COND_54;
int32_t *func_39(int32_t *p_40)
{
BS_VEC(uint64_t, 16) BS_VAR_0 = { 9 };
uint64_t LOCAL_CHECKSUM = 0;
int32_t l_82;
int32_t l_77 = -1;
BS_LABEL_3:
l_77 = safe_mod_func_uint16_t_u_u(, l_82 = l_77) > l_77;
if (func_39_BS_COND_54) goto BS_LABEL_3;
int32_t BS_TEMP_516 = l_82;
BS_VAR_0[BS_TEMP_516 < 0] = 0;
for (uint32_t BS_TEMP_517 = 0; BS_TEMP_517 < 6; BS_TEMP_517++)
LOCAL_CHECKSUM ^= BS_VAR_0[BS_TEMP_517];
BS_CHECKSUM += LOCAL_CHECKSUM;
return p_40;
}
int main()
{
func_39(0);
printf("BackSmith Checksum = 0x%016llx\n", BS_CHECKSUM);
}
Command:
> aarch64-unknown-linux-musl-gcc -O1 -march=armv9-a+sve -static a.c
> qemu-aarch64 a.out
BackSmith Checksum = 0x0000000000000009
> aarch64-unknown-linux-musl-gcc -O2 -march=armv9-a+sve -static a.c
> qemu-aarch64 a.out
BackSmith Checksum = 0x0000000000000000
