glsl: process local_size_variable input qualifier

This is the new layout qualifier introduced by
ARB_compute_variable_group_size which allows to use a variable work
group size.

v4: - add missing '%s' in the monster format string

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

src/compiler/glsl/ast.h

@@ -553,6 +553,11 @@ struct ast_type_qualifier {
           */
          unsigned local_size:3;
 
+	 /** \name Layout qualifiers for ARB_compute_variable_group_size. */
+	 /** \{ */
+	 unsigned local_size_variable:1;
+	 /** \} */
+
 	 /** \name Layout and memory qualifiers for ARB_shader_image_load_store. */
 	 /** \{ */
 	 unsigned early_fragment_tests:1;

src/compiler/glsl/ast_type.cpp

@@ -497,6 +497,7 @@ ast_type_qualifier::merge_in_qualifier(YYLTYPE *loc,
          state->in_qualifier->flags.q.local_size == 0;
 
       valid_in_mask.flags.q.local_size = 7;
+      valid_in_mask.flags.q.local_size_variable = 1;
       break;
    default:
       _mesa_glsl_error(loc, state,
@@ -573,6 +574,10 @@ ast_type_qualifier::merge_in_qualifier(YYLTYPE *loc,
       this->point_mode = q.point_mode;
    }
 
+   if (q.flags.q.local_size_variable) {
+      state->cs_input_local_size_variable_specified = true;
+   }
+
    if (create_node) {
       if (create_gs_ast) {
          node = new(mem_ctx) ast_gs_input_layout(*loc, q.prim_type);
@@ -607,7 +612,7 @@ ast_type_qualifier::validate_flags(YYLTYPE *loc,
                     "%s '%s':"
                     "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s"
                     "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s"
-                    "%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
+                    "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n",
                     message, name,
                     bad.flags.q.invariant ? " invariant" : "",
                     bad.flags.q.precise ? " precise" : "",
@@ -646,6 +651,7 @@ ast_type_qualifier::validate_flags(YYLTYPE *loc,
                     bad.flags.q.prim_type ? " prim_type" : "",
                     bad.flags.q.max_vertices ? " max_vertices" : "",
                     bad.flags.q.local_size ? " local_size" : "",
+                    bad.flags.q.local_size_variable ? " local_size_variable" : "",
                     bad.flags.q.early_fragment_tests ? " early_fragment_tests" : "",
                     bad.flags.q.explicit_image_format ? " image_format" : "",
                     bad.flags.q.coherent ? " coherent" : "",

src/compiler/glsl/glsl_parser.yy

@@ -1491,6 +1491,19 @@ layout_qualifier_id:
          }
       }
 
+      /* Layout qualifiers for ARB_compute_variable_group_size. */
+      if (!$$.flags.i) {
+         if (match_layout_qualifier($1, "local_size_variable", state) == 0) {
+            $$.flags.q.local_size_variable = 1;
+         }
+
+         if ($$.flags.i && !state->ARB_compute_variable_group_size_enable) {
+            _mesa_glsl_error(& @1, state,
+                             "qualifier `local_size_variable` requires "
+                             "ARB_compute_variable_group_size");
+         }
+      }
+
       if (!$$.flags.i) {
          _mesa_glsl_error(& @1, state, "unrecognized layout identifier "
                           "`%s'", $1);

src/compiler/glsl/glsl_parser_extras.cpp

@@ -297,6 +297,8 @@ _mesa_glsl_parse_state::_mesa_glsl_parse_state(struct gl_context *_ctx,
           sizeof(this->atomic_counter_offsets));
    this->allow_extension_directive_midshader =
       ctx->Const.AllowGLSLExtensionDirectiveMidShader;
+
+   this->cs_input_local_size_variable_specified = false;
 }
 
 /**
@@ -1676,6 +1678,7 @@ set_shader_inout_layout(struct gl_shader *shader,
    if (shader->Stage != MESA_SHADER_COMPUTE) {
       /* Should have been prevented by the parser. */
       assert(!state->cs_input_local_size_specified);
+      assert(!state->cs_input_local_size_variable_specified);
    }
 
    if (shader->Stage != MESA_SHADER_FRAGMENT) {
@@ -1791,6 +1794,9 @@ set_shader_inout_layout(struct gl_shader *shader,
          for (int i = 0; i < 3; i++)
             shader->info.Comp.LocalSize[i] = 0;
       }
+
+      shader->info.Comp.LocalSizeVariable =
+         state->cs_input_local_size_variable_specified;
       break;
 
    case MESA_SHADER_FRAGMENT:

src/compiler/glsl/glsl_parser_extras.h

@@ -404,6 +404,12 @@ struct _mesa_glsl_parse_state {
     */
    unsigned cs_input_local_size[3];
 
+   /**
+    * True if a compute shader input local variable size was specified using
+    * a layout directive as specified by ARB_compute_variable_group_size.
+    */
+   bool cs_input_local_size_variable_specified;
+
    /**
     * Output layout qualifiers from GLSL 1.50 (geometry shader controls),
     * and GLSL 4.00 (tessellation control shader).