radeonsi/nir: disable GLSL IR loop unrolling

Delaying unrolling and allowing NIR to do it instead has been shown
to result in better code in drivers such as i965. shader-db results
appear to show the same is true for radeonsi.

The other advantage is that using NIR unrolling improves compile
times significantly.

Totals from affected shaders:
SGPRS: 9624 -> 10016 (4.07 %)
VGPRS: 6800 -> 6464 (-4.94 %)
Spilled SGPRs: 0 -> 2 (0.00 %)
Spilled VGPRs: 0 -> 0 (0.00 %)
Private memory VGPRs: 0 -> 0 (0.00 %)
Scratch size: 0 -> 0 (0.00 %) dwords per thread
Code Size: 359176 -> 332264 (-7.49 %) bytes
LDS: 0 -> 0 (0.00 %) blocks
Max Waves: 1355 -> 1432 (5.68 %)
Wait states: 0 -> 0 (0.00 %)

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
This commit is contained in:
Timothy Arceri 2018-02-21 12:30:30 +11:00
parent e6269ffc2e
commit 79dc94828a
1 changed files with 2 additions and 0 deletions

View File

@ -441,6 +441,8 @@ static int si_get_shader_param(struct pipe_screen* pscreen,
case PIPE_SHADER_CAP_MAX_SHADER_IMAGES:
return SI_NUM_IMAGES;
case PIPE_SHADER_CAP_MAX_UNROLL_ITERATIONS_HINT:
if (sscreen->debug_flags & DBG(NIR))
return 0;
return 32;
case PIPE_SHADER_CAP_PREFERRED_IR:
if (sscreen->debug_flags & DBG(NIR))