https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100088
Bug ID: 100088
Summary: ymm store split into two xmm stores
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: yyc1992 at gmail dot com
Target Milestone: ---
The following code
```
__attribute__((target("avx2")))
void fill_avx2(double *__restrict__ data, int n, double value)
{
for (int i = 0; i < n * 16; i++) {
data[i] = value;
}
}
```
compiles to
```
fill_avx2:
sall $4, %esi
testl %esi, %esi
jle .L5
shrl $2, %esi
vbroadcastsd %xmm0, %ymm0
movl %esi, %eax
salq $5, %rax
addq %rdi, %rax
.p2align 4,,10
.p2align 3
.L3:
vmovupd %xmm0, (%rdi)
vextractf128 $0x1, %ymm0, 16(%rdi)
addq $32, %rdi
cmpq %rax, %rdi
jne .L3
vzeroupper
.L5:
ret
```
Note that AFAICT
```
vmovupd %xmm0, (%rdi)
vextractf128 $0x1, %ymm0, 16(%rdi)
```
is equivalent to
```
vmovupd %ymm0, (%rdi)
```
This issue does not exist for sse or avx512f. Setting `-march=haswell` or
`-mtune=haswell` on the command line also seems to fix this but neither of
these works when added to the target attribute.
