glsl: Convert ir_function_signature::is_builtin to a method.

A signature is a built-in if and only if builtin_info != NULL, so we
don't actually need a separate flag bit.  Making a boolean-valued
method allows existing code to ask the same question while not worrying
about the internal representation.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Paul Berry <stereotype441@gmail.com>

src/glsl/ir.cpp

@@ -1585,11 +1585,17 @@ ir_function_signature::ir_function_signature(const glsl_type *return_type,
      _function(NULL)
 {
    this->ir_type = ir_type_function_signature;
-   this->is_builtin = builtin_info != NULL;
    this->origin = NULL;
 }
 
 
+bool
+ir_function_signature::is_builtin() const
+{
+   return builtin_info != NULL;
+}
+
+
 static bool
 modes_match(unsigned a, unsigned b)
 {
@@ -1661,7 +1667,7 @@ ir_function::has_user_signature()
 {
    foreach_list(n, &this->signatures) {
       ir_function_signature *const sig = (ir_function_signature *) n;
-      if (!sig->is_builtin)
+      if (!sig->is_builtin())
 	 return true;
    }
    return false;

src/glsl/ir.h

@@ -684,7 +684,7 @@ public:
    unsigned is_defined:1;
 
    /** Whether or not this function signature is a built-in. */
-   unsigned is_builtin:1;
+   bool is_builtin() const;
 
    /** Body of instructions in the function. */
    struct exec_list body;
@@ -1321,7 +1321,7 @@ public:
       ir_type = ir_type_call;
       assert(callee->return_type != NULL);
       actual_parameters->move_nodes_to(& this->actual_parameters);
-      this->use_builtin = callee->is_builtin;
+      this->use_builtin = callee->is_builtin();
    }
 
    virtual ir_call *clone(void *mem_ctx, struct hash_table *ht) const;

src/glsl/ir_clone.cpp

@@ -329,7 +329,6 @@ ir_function_signature::clone_prototype(void *mem_ctx, struct hash_table *ht) con
       new(mem_ctx) ir_function_signature(this->return_type);
 
    copy->is_defined = false;
-   copy->is_builtin = this->is_builtin;
    copy->builtin_info = this->builtin_info;
    copy->origin = this;
 

src/glsl/ir_constant_expression.cpp

@@ -1840,7 +1840,7 @@ ir_function_signature::constant_expression_value(exec_list *actual_parameters, s
     * "Function calls to user-defined functions (non-built-in functions)
     *  cannot be used to form constant expressions."
     */
-   if (!this->is_builtin)
+   if (!this->is_builtin())
       return NULL;
 
    /*

src/glsl/link_functions.cpp

@@ -116,7 +116,7 @@ public:
 	 f->exact_matching_signature(&callee->parameters);
       if ((linked_sig == NULL)
 	  || ((linked_sig != NULL)
-	      && (linked_sig->is_builtin != ir->use_builtin))) {
+	      && (linked_sig->is_builtin() != ir->use_builtin))) {
 	 linked_sig = new(linked) ir_function_signature(callee->return_type);
 	 f->add_signature(linked_sig);
       }
@@ -297,7 +297,7 @@ find_matching_signature(const char *name, const exec_list *actual_parameters,
        * signature that we found isn't a built-in, keep looking.  Also keep
        * looking if we expect a non-built-in but found a built-in.
        */
-      if (use_builtin != sig->is_builtin)
+      if (use_builtin != sig->is_builtin())
 	    continue;
 
       return sig;

src/glsl/linker.cpp

@@ -1163,14 +1163,14 @@ link_intrastage_shaders(void *mem_ctx,
 	       ir_function_signature *sig =
 		  (ir_function_signature *) iter.get();
 
-	       if (!sig->is_defined || sig->is_builtin)
+	       if (!sig->is_defined || sig->is_builtin())
 		  continue;
 
 	       ir_function_signature *other_sig =
 		  other->exact_matching_signature(& sig->parameters);
 
 	       if ((other_sig != NULL) && other_sig->is_defined
-		   && !other_sig->is_builtin) {
+		   && !other_sig->is_builtin()) {
 		  linker_error(prog, "function `%s' is multiply defined",
 			       f->name);
 		  return NULL;