[Mesa-dev] [PATCH] i965: Use NIR by default for vertex shaders on GEN8+

[Jason Ekstrand]

GLSL IR vs. NIR shader-db results for SIMD8 vertex shaders on Broadwell:

   total instructions in shared programs: 2724483 -> 2711790 (-0.47%)
   instructions in affected programs:     1860859 -> 1848166 (-0.68%)
   helped:                                4387
   HURT:                                  4758
   GAINED:                                1499

The gained programs are ARB vertext programs that were previously going
through the vec4 backend.  Now that we have prog_to_nir, ARB vertex
programs can go through the scalar backend so they show up as "gained" in
the shader-db results.
---
 src/mesa/drivers/dri/i965/brw_context.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index fd7420a..8615e5e 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -588,7 +588,7 @@ brw_initialize_context_constants(struct brw_context *brw)
       ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].EmitNoIndirectTemp = true;
       ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].OptimizeForAOS = false;
 
-      if (brw_env_var_as_boolean("INTEL_USE_NIR", false))
+      if (brw_env_var_as_boolean("INTEL_USE_NIR", true))
          ctx->Const.ShaderCompilerOptions[MESA_SHADER_VERTEX].NirOptions = &nir_options;
    }
 
-- 
2.4.0