From 88f5588f777d76fe48fded8add745b4da2024ebc Mon Sep 17 00:00:00 2001 From: Ian Romanick Date: Tue, 31 Oct 2017 22:18:10 -0700 Subject: [PATCH] glsl/linker: Optimize swizzles again after linking Without this, the SPIR-V generator has to deal with a bunch of junk like: (swiz z (swiz xxx (swiz x (var_ref packed:binormal.z,light_dir)))) It seems better to cull that stuff out than to add code to deal with it. The problem is the way swizzles to and from scalars have to be handled in SPIR-V. Signed-off-by: Ian Romanick Reviewed-by: Thomas Helland --- src/compiler/glsl/linker.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp index d6f9c2d91ff..33fd76deae9 100644 --- a/src/compiler/glsl/linker.cpp +++ b/src/compiler/glsl/linker.cpp @@ -5079,6 +5079,16 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog) if(!link_varyings_and_uniforms(first, last, ctx, prog, mem_ctx)) goto done; + /* Linking varyings can cause some extra, useless swizzles to be generated + * due to packing and unpacking. + */ + for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) { + if (prog->_LinkedShaders[i] == NULL) + continue; + + optimize_swizzles(prog->_LinkedShaders[i]->ir); + } + /* OpenGL ES < 3.1 requires that a vertex shader and a fragment shader both * be present in a linked program. GL_ARB_ES2_compatibility doesn't say * anything about shader linking when one of the shaders (vertex or -- 2.30.2