glsl: Add "built-in" functions to do 64x64 => 64 multiplication

These functions are directly available in shaders.  A #define is added
to detect the presence.  This allows these functions to be tested using
piglit regardless of whether the driver uses them for lowering.  The
GLSL spec says that functions and macros beginning with __ are reserved
for use by the implementation... hey, that's us!

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

src/compiler/glsl/glcpp/glcpp-parse.y

@@ -1334,7 +1334,8 @@ add_builtin_define(glcpp_parser_t *parser, const char *name, int value)
 }
 
 glcpp_parser_t *
-glcpp_parser_create(glcpp_extension_iterator extensions, void *state, gl_api api)
+glcpp_parser_create(const struct gl_extensions *extension_list,
+                    glcpp_extension_iterator extensions, void *state, gl_api api)
 {
    glcpp_parser_t *parser;
 
@@ -1369,6 +1370,7 @@ glcpp_parser_create(glcpp_extension_iterator extensions, void *state, gl_api api
    parser->error = 0;
 
    parser->extensions = extensions;
+   parser->extension_list = extension_list;
    parser->state = state;
    parser->api = api;
    parser->version = 0;
@@ -2335,6 +2337,16 @@ _glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t versio
       parser->extensions(parser->state, add_builtin_define, parser,
                          version, parser->is_gles);
 
+   if (parser->extension_list) {
+      /* If MESA_shader_integer_functions is supported, then the building
+       * blocks required for the 64x64 => 64 multiply exist.  Add defines for
+       * those functions so that they can be tested.
+       */
+      if (parser->extension_list->MESA_shader_integer_functions) {
+         add_builtin_define(parser, "__have_builtin_builtin_umul64", 1);
+      }
+   }
+
    if (explicitly_set) {
       ralloc_asprintf_rewrite_tail(&parser->output, &parser->output_length,
                                    "#version %" PRIiMAX "%s%s", version,

src/compiler/glsl/glcpp/glcpp.h

@@ -205,6 +205,7 @@ struct glcpp_parser {
 	size_t info_log_length;
 	int error;
 	glcpp_extension_iterator extensions;
+	const struct gl_extensions *extension_list;
 	void *state;
 	gl_api api;
 	unsigned version;
@@ -225,7 +226,8 @@ struct glcpp_parser {
 };
 
 glcpp_parser_t *
-glcpp_parser_create (glcpp_extension_iterator extensions, void *state, gl_api api);
+glcpp_parser_create(const struct gl_extensions *extension_list,
+                    glcpp_extension_iterator extensions, void *state, gl_api api);
 
 int
 glcpp_parser_parse (glcpp_parser_t *parser);

src/compiler/glsl/glcpp/pp.c

@@ -218,7 +218,7 @@ glcpp_preprocess(void *ralloc_ctx, const char **shader, char **info_log,
 {
 	int errors;
 	glcpp_parser_t *parser =
-		glcpp_parser_create(extensions, state, gl_ctx->API);
+		glcpp_parser_create(&gl_ctx->Extensions, extensions, state, gl_ctx->API);
 
 	if (! gl_ctx->Const.DisableGLSLLineContinuations)
 		*shader = remove_line_continuations(parser, *shader);