[Mesa-dev] [PATCH V3 2/2] glsl: don't run the GLSL pre-processor when we are skipping compilation

[Timothy Arceri]

Improves Deus Ex start-up times with a warm cache from ~30 seconds to
~22 seconds.

Also fixes the leaking of state.

V2: fix indentation

v3: add the value of MESA_EXTENSION_OVERRIDE to the hash of the shader.

Tested-by (v2): Grazvydas Ignotas <notasas at gmail.com>
---
 src/compiler/glsl/glsl_parser_extras.cpp | 19 ++++++++++---------
 src/compiler/glsl/shader_cache.cpp       | 10 ++++++++++
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/compiler/glsl/glsl_parser_extras.cpp b/src/compiler/glsl/glsl_parser_extras.cpp
index ca74b55..eb12eff 100644
--- a/src/compiler/glsl/glsl_parser_extras.cpp
+++ b/src/compiler/glsl/glsl_parser_extras.cpp
@@ -1998,32 +1998,23 @@ opt_shader_and_create_symbol_table(struct gl_context *ctx,
       }
    }
 
    _mesa_glsl_initialize_derived_variables(ctx, shader);
 }
 
 void
 _mesa_glsl_compile_shader(struct gl_context *ctx, struct gl_shader *shader,
                           bool dump_ast, bool dump_hir, bool force_recompile)
 {
-   struct _mesa_glsl_parse_state *state =
-      new(shader) _mesa_glsl_parse_state(ctx, shader->Stage, shader);
    const char *source = force_recompile && shader->FallbackSource ?
       shader->FallbackSource : shader->Source;
 
-   if (ctx->Const.GenerateTemporaryNames)
-      (void) p_atomic_cmpxchg(&ir_variable::temporaries_allocate_names,
-                              false, true);
-
-   state->error = glcpp_preprocess(state, &source, &state->info_log,
-                             add_builtin_defines, state, ctx);
-
    if (!force_recompile) {
       if (ctx->Cache) {
          char buf[41];
          disk_cache_compute_key(ctx->Cache, source, strlen(source),
                                 shader->sha1);
          if (disk_cache_has_key(ctx->Cache, shader->sha1)) {
             /* We've seen this shader before and know it compiles */
             if (ctx->_Shader->Flags & GLSL_CACHE_INFO) {
                _mesa_sha1_format(buf, shader->sha1);
                fprintf(stderr, "deferring compile of shader: %s\n", buf);
@@ -2043,20 +2034,30 @@ _mesa_glsl_compile_shader(struct gl_context *ctx, struct gl_shader *shader,
       if (shader->CompileStatus == compile_success)
          return;
 
       if (shader->CompileStatus == compiled_no_opts) {
          opt_shader_and_create_symbol_table(ctx, shader);
          shader->CompileStatus = compile_success;
          return;
       }
    }
 
+   struct _mesa_glsl_parse_state *state =
+      new(shader) _mesa_glsl_parse_state(ctx, shader->Stage, shader);
+
+   if (ctx->Const.GenerateTemporaryNames)
+      (void) p_atomic_cmpxchg(&ir_variable::temporaries_allocate_names,
+                              false, true);
+
+   state->error = glcpp_preprocess(state, &source, &state->info_log,
+                                   add_builtin_defines, state, ctx);
+
    if (!state->error) {
      _mesa_glsl_lexer_ctor(state, source);
      _mesa_glsl_parse(state);
      _mesa_glsl_lexer_dtor(state);
      do_late_parsing_checks(state);
    }
 
    if (dump_ast) {
       foreach_list_typed(ast_node, ast, link, &state->translation_unit) {
          ast->print();
diff --git a/src/compiler/glsl/shader_cache.cpp b/src/compiler/glsl/shader_cache.cpp
index e51fecd..738e548 100644
--- a/src/compiler/glsl/shader_cache.cpp
+++ b/src/compiler/glsl/shader_cache.cpp
@@ -1312,20 +1312,30 @@ shader_cache_read_program_metadata(struct gl_context *ctx,
                           prog->SeparateShader ? "T" : "F");
 
    /* A shader might end up producing different output depending on the glsl
     * version supported by the compiler. For example a different path might be
     * taken by the preprocessor, so add the version to the hash input.
     */
    ralloc_asprintf_append(&buf, "api: %d glsl: %d fglsl: %d\n",
                           ctx->API, ctx->Const.GLSLVersion,
                           ctx->Const.ForceGLSLVersion);
 
+   /* We run the preprocessor on shaders after hashing them, so we need to
+    * add any extension override vars to the hash. If we don't do this the
+    * preprocessor could result in different output and we could load the
+    * wrong shader.
+    */
+   char *ext_override = getenv("MESA_EXTENSION_OVERRIDE");
+   if (ext_override) {
+      ralloc_asprintf_append(&buf, "ext:%s", ext_override);
+   }
+
    /* DRI config options may also change the output from the compiler so
     * include them as an input to sha1 creation.
     */
    char sha1buf[41];
    _mesa_sha1_format(sha1buf, ctx->Const.dri_config_options_sha1);
    ralloc_strcat(&buf, sha1buf);
 
    for (unsigned i = 0; i < prog->NumShaders; i++) {
       struct gl_shader *sh = prog->Shaders[i];
       _mesa_sha1_format(sha1buf, sh->sha1);
-- 
2.9.3