https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104010
Bug ID: 104010
Summary: [12 regression] short loop no longer vectorized with
Neon after r12-6513
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: clyon at gcc dot gnu.org
Target Milestone: ---
This short loop:
void test_vcmpeq_s32x2 (int32_t * __restrict__ dest, int32_t *a, int32_t *b)
{
int i;
for (i=0; i<4; i++) {
dest[i] = a[i] == b[i];
}
}
used to be vectorized as:
test_vcmpeq_s32x2:
vld1.32 {d16}, [r1]
vmov.i32 d17, #0x1 @ v2si
vld1.32 {d19}, [r2]
vmov.i32 d18, #0 @ v2si
vceq.i32 d16, d16, d19
vbsl d16, d17, d18
vst1.32 {d16}, [r0]
bx lr
After r12-6513, we get:
test_vcmpeq_s32x2:
ldr ip, [r1]
ldr r3, [r1, #4]
str lr, [sp, #-4]!
ldr lr, [r2]
ldr r2, [r2, #4]
sub ip, ip, lr
clz ip, ip
sub r3, r3, r2
lsr ip, ip, #5
clz r3, r3
lsr r3, r3, #5
str ip, [r0]
str r3, [r0, #4]
ldr pc, [sp], #4
when compiling for arm-none-linux-gnueabihf with -mcpu=cortex-a9 -mfpu=neon
