mesa: add gl_constants::GLSLOptimizeConservatively

to reduce the amount of GLSL optimizations for drivers that can do better.

Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/mesa/main/ff_fragment_shader.cpp b/src/mesa/main/ff_fragment_shader.cpp
index fd2c71f93ee..48b84e8fd73 100644
--- a/src/mesa/main/ff_fragment_shader.cpp
+++ b/src/mesa/main/ff_fragment_shader.cpp
@@ -1254,9 +1254,13 @@ create_new_program(struct gl_context *ctx, struct state_key *key)
    const struct gl_shader_compiler_options *options =
       &ctx->Const.ShaderCompilerOptions[MESA_SHADER_FRAGMENT];
 
-   while (do_common_optimization(p.shader->ir, false, false, options,
-                                 ctx->Const.NativeIntegers))
-      ;
+   /* Conservative approach: Don't optimize here, the linker does it too. */
+   if (!ctx->Const.GLSLOptimizeConservatively) {
+      while (do_common_optimization(p.shader->ir, false, false, options,
+                                    ctx->Const.NativeIntegers))
+         ;
+   }
+
    reparent_ir(p.shader->ir, p.shader->ir);
 
    p.shader->CompileStatus = true;