glsl: Defer initialization of built-in functions until they're needed.

Very simple shaders don't actually use GLSL built-ins.  For example:
- gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
- gl_FragColor = vec4(0.0);
Both of the shaders used by _mesa_meta_glsl_Clear() also qualify.

By waiting to initialize the built-ins until the first time we need to
look for a signature, we can avoid the overhead entirely in these cases.

Makes piglit run roughly 18% faster (255 vs. 312 seconds).

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>

1 files changed, 0 insertions, 1 deletions

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index ce29d5a87aa..91a2231605d 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -60,7 +60,6 @@ void
 _mesa_ast_to_hir(exec_list *instructions, struct _mesa_glsl_parse_state *state)
 {
    _mesa_glsl_initialize_variables(instructions, state);
-   _mesa_glsl_initialize_functions(state);
 
    state->symbols->language_version = state->language_version;