Skip to content

amd: lower gl_FragCoord.w rcp in NIR

Georg Lehmann requested to merge DadSchoorse/mesa:amd-lower-wrcp into main

This allows NIR to remove the rcps if the application uses rcp(gl_FragCoord.w). D3D provides w, not 1/w like GL/VK in the shader, so this is commonly used.

Foz-DB Navi21:
Totals from 2068 (2.61% of 79206) affected shaders:
MaxWaves: 45636 -> 45652 (+0.04%)
Instrs: 2173444 -> 2169671 (-0.17%); split: -0.18%, +0.00%
CodeSize: 11881304 -> 11867208 (-0.12%); split: -0.12%, +0.01%
VGPRs: 118000 -> 117968 (-0.03%)
Latency: 35689676 -> 35675909 (-0.04%); split: -0.06%, +0.02%
InvThroughput: 9167199 -> 9159801 (-0.08%); split: -0.08%, +0.00%
VClause: 45076 -> 45078 (+0.00%); split: -0.01%, +0.02%
SClause: 92503 -> 92366 (-0.15%); split: -0.31%, +0.17%
Copies: 140282 -> 140303 (+0.01%); split: -0.13%, +0.14%
Branches: 53347 -> 53346 (-0.00%); split: -0.01%, +0.00%
PreVGPRs: 96495 -> 96465 (-0.03%)
VALU: 1522980 -> 1519252 (-0.24%); split: -0.25%, +0.01%
SALU: 213451 -> 213460 (+0.00%); split: -0.02%, +0.02%

Merge request reports