You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
[AMDGPU][True16][CodeGen] fix moveToVALU with proper subreg access in true16 (#132089)
There are V2S copies between vpgr16 and spgr32 in true16 mode. This is
caused by vgpr16 and sgpr32 both selectable by 16bit src in ISel.
When a V2S copy and its useMI are lowered to VALU, this patch check
1. If the generated new VALU is used by a true16 inst. Add subreg access
if necessary.
2. Legalize the V2S copy by replacing it to subreg_to_reg
an example MIR looks like:
```
%2:sgpr_32 = COPY %1:vgpr_16
%3:sgpr_32 = S_OR_B32 %2:sgpr_32, ...
%4:vgpr_16 = V_ADD_F16_t16 %3:sgpr_32, ...
```
currently lowered to
```
%2:vgpr_32 = COPY %1:vgpr_16
%3:vgpr_32 = V_OR_B32 %2:vgpr_32, ...
%4:vgpr_16 = V_ADD_F16_t16 %3:vgpr_32, ...
```
after this patch
```
%2:vgpr_32 = SUBREG_TO_REG 0, %1:vgpr_16, lo16
%3:vgpr_32 = V_OR_B32 %2:vgpr_32, ...
%4:vgpr_16 = V_ADD_F16_t16 %3.lo16:vgpr_32, ...
```
0 commit comments