glsl: lower constant arrays to uniform arrays before optimisation loop

Previously the constant array would not get copy propagated until the backend
did its GLSL IR opt loop. I plan on removing that from i965 shortly which
caused huge regressions in Deus-ex and Tomb Raider which have large
constant arrays. Moving lowering before the opt loop in the GLSL linker
fixes this and unexpectedly improves some compute shaders also.

shader-db results BDW:

instructions helped:   shaders/closed/steam/deus-ex-mankind-divided/374.shader_test CS SIMD16: 204 -> 194 (-4.90%)
instructions helped:   shaders/closed/steam/deus-ex-mankind-divided/318.shader_test CS SIMD8: 1010 -> 741 (-26.63%)
instructions helped:   shaders/closed/steam/deus-ex-mankind-divided/144.shader_test CS SIMD8: 542 -> 385 (-28.97%)

cycles helped:   shaders/closed/steam/deus-ex-mankind-divided/318.shader_test CS SIMD8: 1831382 -> 1818492 (-0.70%)
cycles helped:   shaders/closed/steam/deus-ex-mankind-divided/144.shader_test CS SIMD8: 216238 -> 206180 (-4.65%)
cycles helped:   shaders/closed/steam/deus-ex-mankind-divided/374.shader_test CS SIMD16: 18484 -> 16644 (-9.95%)

total instructions in shared programs: 13060313 -> 13059877 (-0.00%)
instructions in affected programs: 1756 -> 1320 (-24.83%)
helped: 3
HURT: 0

total cycles in shared programs: 256586698 -> 256561910 (-0.01%)
cycles in affected programs: 2066104 -> 2041316 (-1.20%)
helped: 3
HURT: 0

V3: only call the opt loop if lowering progressed (Suggested by Eric)

V2: call opts before and after lowering (Suggested by Ken)

Reviewed-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Timothy Arceri
2017-01-24 14:07:04 +11:00
committed by Timothy Arceri
parent c4a0c1efff
commit 34ab9b0947

View File

@@ -4608,6 +4608,24 @@ link_varyings_and_uniforms(unsigned first, unsigned last,
return true; return true;
} }
static void
linker_optimisation_loop(struct gl_context *ctx, exec_list *ir,
unsigned stage)
{
if (ctx->Const.GLSLOptimizeConservatively) {
/* Run it just once. */
do_common_optimization(ir, true, false,
&ctx->Const.ShaderCompilerOptions[stage],
ctx->Const.NativeIntegers);
} else {
/* Repeat it until it stops making changes. */
while (do_common_optimization(ir, true, false,
&ctx->Const.ShaderCompilerOptions[stage],
ctx->Const.NativeIntegers))
;
}
}
void void
link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
{ {
@@ -4882,20 +4900,15 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
lower_tess_level(prog->_LinkedShaders[i]); lower_tess_level(prog->_LinkedShaders[i]);
} }
if (ctx->Const.GLSLOptimizeConservatively) { /* Call opts before lowering const arrays to uniforms so we can const
/* Run it just once. */ * propagate any elements accessed directly.
do_common_optimization(prog->_LinkedShaders[i]->ir, true, false, */
&ctx->Const.ShaderCompilerOptions[i], linker_optimisation_loop(ctx, prog->_LinkedShaders[i]->ir, i);
ctx->Const.NativeIntegers);
} else { /* Call opts after lowering const arrays to copy propagate things. */
/* Repeat it until it stops making changes. */ if (lower_const_arrays_to_uniforms(prog->_LinkedShaders[i]->ir, i))
while (do_common_optimization(prog->_LinkedShaders[i]->ir, true, false, linker_optimisation_loop(ctx, prog->_LinkedShaders[i]->ir, i);
&ctx->Const.ShaderCompilerOptions[i],
ctx->Const.NativeIntegers))
;
}
lower_const_arrays_to_uniforms(prog->_LinkedShaders[i]->ir, i);
propagate_invariance(prog->_LinkedShaders[i]->ir); propagate_invariance(prog->_LinkedShaders[i]->ir);
} }