https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112306
Bug ID: 112306
Summary: [AArch64][neon] incorrect combine the (a -1)* b into
fnmsub for fixed vector type
Product: gcc
Version: 13.1.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: zhongyunde at huawei dot com
Target Milestone: ---
* test: https://gcc.godbolt.org/z/sr6Mevf9G
```
float32x4_t test2_float_vec (float32x4_t a, float32x4_t b) {
return -b + a * b;
}
```
* it seems not right for gcc to generate the a single **fnmsub s0, s0, s1,
s1**, because the variables of a and b are vector type, while the output use a
scalar float type registers ?
