https://bugs.llvm.org/show_bug.cgi?id=45314
Bug ID: 45314
Summary: Redundant vmov{q,d} before 32-bit splat
Product: libraries
Version: trunk
Hardware: PC
OS: Windows NT
Status: NEW
Severity: enhancement
Priority: P
Component: Backend: X86
Assignee: unassignedb...@nondot.org
Reporter: d...@dsprenkels.com
CC: craig.top...@gmail.com, llvm-bugs@lists.llvm.org,
llvm-...@redking.me.uk, spatel+l...@rotateright.com
The following code:
```
#include <immintrin.h>
__m256i broadcast(const __m256i x) {
return _mm256_set_epi32(x[0], x[0], x[0], x[0], x[0], x[0], x[0], x[0]);
}
```
is compiled to:
```
broadcast: # @broadcast
vmovq rax, xmm0
vmovd xmm0, eax
vpbroadcastd ymm0, xmm0
ret
```
These two vmov operations are redundant.
GCC already omits these operations:
```
broadcast:
vpbroadcastd ymm0, xmm0
ret
```
Godbolt link: https://c.godbolt.org/z/bkVDWj
--
You are receiving this mail because:
You are on the CC list for the bug._______________________________________________
llvm-bugs mailing list
llvm-bugs@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-bugs
