https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113869
Bug ID: 113869
Summary: V4HF->V4SF pattern seems to be missing
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: enhancement
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Target: aarch64
Take:
```
void f( _Float16 * __restrict a, float * __restrict b)
{
b[0] = a[0];
b[1] = a[1];
b[2] = a[2];
b[3] = a[3];
b+=4;a+=4;
#if 0
b[0] = a[0];
b[1] = a[1];
b[2] = a[2];
b[3] = a[3];
#endif
}
```
The pattern that converts V4HF to V4SF seems be to missing and we don't SLP the
above. We able to handle V8HF to V8SF which does:
```
fcvtl v30.4s, v31.4h
fcvtl2 v31.4s, v31.8h
```
But the first fcvtl is exactly what we want for V4HF->V4SF.
