https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123544
Bug ID: 123544
Summary: [16 Regression] AArch64: Wrong code at -O1
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 20260108 (experimental)
qemu-aarch64 version 10.1.2
Testcase:
#include <stdint.h>
#include <stdio.h>
#define BS_VEC(type, num) type __attribute__((vector_size(num)))
uint64_t BS_CHECKSUM;
int8_t backsmith_pure_0() {}
uint32_t backsmith_pure_4(BS_VEC(uint8_t, 4) BS_ARG_1, int16_t BS_ARG_2,
int64_t BS_ARG_5)
{
_BitInt(15) BS_VAR_0 = 828;
BS_VAR_0 &= (unsigned)BS_ARG_5 < 5 ? 0 : (unsigned)BS_ARG_1[1];
if (BS_ARG_2) return BS_VAR_0;
for (uint16_t BS_INC_0; BS_INC_0;)
;
}
int32_t func_8(uint8_t p_9)
{
uint64_t BS_VAR_0[] = {};
uint64_t LOCAL_CHECKSUM =
backsmith_pure_4((BS_VEC(uint8_t, 4)){ 1, 1, 1 }, 1, -1);
if (p_9)
{
BS_CHECKSUM += LOCAL_CHECKSUM;
return 0;
}
BS_VAR_0[backsmith_pure_4((BS_VEC(uint8_t, 4)){}, 0, backsmith_pure_0())];
}
int main()
{
func_8(1);
printf("BackSmith Checksum = 0x%016llx\n", BS_CHECKSUM);
}
Command:
> aarch64-unknown-linux-musl-gcc -O1 -static a.c
> qemu-aarch64 a.out
Output:
> BackSmith Checksum = 0x0000000000000100
Command:
> aarch64-unknown-linux-musl-gcc -O0 -static a.c
> qemu-aarch64 a.out
Output:
> BackSmith Checksum = 0x0000000000000000
