glsl/linker: find built-in variable assignments by location instead of name

This is faster and more compatible with SPIR-V.

1 files changed, 17 insertions, 13 deletions

diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index a051c9d7e3..535a122b3f 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -92,10 +92,12 @@
 namespace {
 
 struct find_variable {
-   const char *name;
+   enum ir_variable_mode mode;
+   unsigned location;
    bool found;
 
-   find_variable(const char *name) : name(name), found(false) {}
+   find_variable(enum ir_variable_mode mode, unsigned location) :
+      mode(mode), location(location), found(false) {}
 };
 
 /**
@@ -115,7 +117,7 @@ public:
    {
       ir_variable *const var = ir->lhs->variable_referenced();
 
-      return check_variable_name(var->name);
+      return check_variable(var);
    }
 
    virtual ir_visitor_status visit_enter(ir_call *ir)
@@ -128,7 +130,7 @@ public:
          if (sig_param->data.mode == ir_var_function_out ||
              sig_param->data.mode == ir_var_function_inout) {
             ir_variable *var = param_rval->variable_referenced();
-            if (var && check_variable_name(var->name) == visit_stop)
+            if (var && check_variable(var) == visit_stop)
                return visit_stop;
          }
       }
@@ -136,7 +138,7 @@ public:
       if (ir->return_deref != NULL) {
          ir_variable *const var = ir->return_deref->variable_referenced();
 
-         if (check_variable_name(var->name) == visit_stop)
+         if (check_variable(var) == visit_stop)
             return visit_stop;
       }
 
@@ -144,10 +146,12 @@ public:
    }
 
 private:
-   ir_visitor_status check_variable_name(const char *name)
+   ir_visitor_status check_variable(ir_variable *var)
    {
       for (unsigned i = 0; i < num_variables; ++i) {
-         if (strcmp(variables[i]->name, name) == 0) {
+         if (variables[i]->mode == var->data.mode &&
+             var->data.explicit_location &&
+             variables[i]->location == var->data.location) {
             if (!variables[i]->found) {
                variables[i]->found = true;
 
@@ -608,9 +612,9 @@ analyze_clip_cull_usage(struct gl_shader_program *prog,
        * gl_ClipVertex nor gl_ClipDistance. However with
        * GL_EXT_clip_cull_distance, this functionality is exposed in ES 3.0.
        */
-      find_variable gl_ClipDistance("gl_ClipDistance");
-      find_variable gl_CullDistance("gl_CullDistance");
-      find_variable gl_ClipVertex("gl_ClipVertex");
+      find_variable gl_ClipDistance(ir_var_shader_out, VARYING_SLOT_CLIP_DIST0);
+      find_variable gl_CullDistance(ir_var_shader_out, VARYING_SLOT_CULL_DIST0);
+      find_variable gl_ClipVertex(ir_var_shader_out, VARYING_SLOT_CLIP_VERTEX);
       find_variable * const variables[] = {
          &gl_ClipDistance,
          &gl_CullDistance,
@@ -718,7 +722,7 @@ validate_vertex_shader_executable(struct gl_shader_program *prog,
     * gl_Position is not an error.
     */
    if (prog->data->Version < (prog->IsES ? 300 : 140)) {
-      find_variable gl_Position("gl_Position");
+      find_variable gl_Position(ir_var_shader_out, VARYING_SLOT_POS);
       find_assignments(shader->ir, &gl_Position);
       if (!gl_Position.found) {
         if (prog->IsES) {
@@ -764,8 +768,8 @@ validate_fragment_shader_executable(struct gl_shader_program *prog,
    if (shader == NULL)
       return;
 
-   find_variable gl_FragColor("gl_FragColor");
-   find_variable gl_FragData("gl_FragData");
+   find_variable gl_FragColor(ir_var_shader_out, FRAG_RESULT_COLOR);
+   find_variable gl_FragData(ir_var_shader_out, FRAG_RESULT_DATA0);
    find_variable * const variables[] = { &gl_FragColor, &gl_FragData, NULL };
    find_assignments(shader->ir, variables);