[Mesa-dev] [PATCH v2] radv: compact varyings after removing unused ones

[Samuel Pitoiset]

It makes no sense to compact before, and the description of
nir_compact_varyings() confirms that.

Polaris10:
Totals from affected shaders:
SGPRS: 108528 -> 108128 (-0.37 %)
VGPRS: 74548 -> 74500 (-0.06 %)
Spilled SGPRs: 844 -> 814 (-3.55 %)
Code Size: 3007328 -> 2992932 (-0.48 %) bytes
Max Waves: 16019 -> 16009 (-0.06 %)

Totals from affected shaders:
Vega10:
SGPRS: 108528 -> 108128 (-0.37 %)
VGPRS: 74548 -> 74500 (-0.06 %)
Spilled SGPRs: 844 -> 814 (-3.55 %)
Code Size: 3007328 -> 2992932 (-0.48 %) bytes
Max Waves: 16019 -> 16009 (-0.06 %)

v2: - compact varyings even if no varyings were removed
    - update shader stats (which are better than v1)

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/vulkan/radv_pipeline.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/amd/vulkan/radv_pipeline.c b/src/amd/vulkan/radv_pipeline.c
index 0d1958fc93..88646fda2f 100644
--- a/src/amd/vulkan/radv_pipeline.c
+++ b/src/amd/vulkan/radv_pipeline.c
@@ -1524,6 +1524,9 @@ radv_link_shaders(struct radv_pipeline *pipeline, nir_shader **shaders)
 		bool progress = nir_remove_unused_varyings(ordered_shaders[i],
 							   ordered_shaders[i - 1]);
 
+		nir_compact_varyings(ordered_shaders[i],
+				     ordered_shaders[i - 1], true);
+
 		if (progress) {
 			if (nir_lower_global_vars_to_local(ordered_shaders[i])) {
 				radv_lower_indirect_derefs(ordered_shaders[i],
@@ -1722,7 +1725,6 @@ void radv_create_shaders(struct radv_pipeline *pipeline,
 		last = i;
 	}
 
-	int prev = -1;
 	for (unsigned i = 0; i < MESA_SHADER_STAGES; ++i) {
 		const VkPipelineShaderStageCreateInfo *stage = pStages[i];
 
@@ -1753,11 +1755,6 @@ void radv_create_shaders(struct radv_pipeline *pipeline,
 			nir_lower_io_to_scalar_early(nir[i], mask);
 			radv_optimize_nir(nir[i]);
 		}
-
-		if (prev != -1) {
-			nir_compact_varyings(nir[prev], nir[i], true);
-		}
-		prev = i;
 	}
 
 	if (nir[MESA_SHADER_TESS_CTRL]) {
-- 
2.16.1