+
+
+/**
+ * Initialize compute shader variables with values that are derived from other
+ * compute shader variable.
+ */
+static void
+initialize_cs_derived_variables(gl_shader *shader,
+ ir_function_signature *const main_sig)
+{
+ assert(shader->Stage == MESA_SHADER_COMPUTE);
+
+ ir_variable *gl_GlobalInvocationID =
+ shader->symbols->get_variable("gl_GlobalInvocationID");
+ assert(gl_GlobalInvocationID);
+ ir_variable *gl_WorkGroupID =
+ shader->symbols->get_variable("gl_WorkGroupID");
+ assert(gl_WorkGroupID);
+ ir_variable *gl_WorkGroupSize =
+ shader->symbols->get_variable("gl_WorkGroupSize");
+ if (gl_WorkGroupSize == NULL) {
+ void *const mem_ctx = ralloc_parent(shader->ir);
+ gl_WorkGroupSize = new(mem_ctx) ir_variable(glsl_type::uvec3_type,
+ "gl_WorkGroupSize",
+ ir_var_auto);
+ gl_WorkGroupSize->data.how_declared = ir_var_declared_implicitly;
+ gl_WorkGroupSize->data.read_only = true;
+ shader->ir->push_head(gl_WorkGroupSize);
+ }
+ ir_variable *gl_LocalInvocationID =
+ shader->symbols->get_variable("gl_LocalInvocationID");
+ assert(gl_LocalInvocationID);
+
+ /* gl_GlobalInvocationID =
+ * gl_WorkGroupID * gl_WorkGroupSize + gl_LocalInvocationID
+ */
+ ir_instruction *inst =
+ assign(gl_GlobalInvocationID,
+ add(mul(gl_WorkGroupID, gl_WorkGroupSize),
+ gl_LocalInvocationID));
+ main_sig->body.push_head(inst);
+
+ /* gl_LocalInvocationIndex =
+ * gl_LocalInvocationID.z * gl_WorkGroupSize.x * gl_WorkGroupSize.y +
+ * gl_LocalInvocationID.y * gl_WorkGroupSize.x +
+ * gl_LocalInvocationID.x;
+ */
+ ir_expression *index_z =
+ mul(mul(swizzle_z(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize)),
+ swizzle_y(gl_WorkGroupSize));
+ ir_expression *index_y =
+ mul(swizzle_y(gl_LocalInvocationID), swizzle_x(gl_WorkGroupSize));
+ ir_expression *index_y_plus_z = add(index_y, index_z);
+ operand index_x(swizzle_x(gl_LocalInvocationID));
+ ir_expression *index_x_plus_y_plus_z = add(index_y_plus_z, index_x);
+ ir_variable *gl_LocalInvocationIndex =
+ shader->symbols->get_variable("gl_LocalInvocationIndex");
+ assert(gl_LocalInvocationIndex);
+ inst = assign(gl_LocalInvocationIndex, index_x_plus_y_plus_z);
+ main_sig->body.push_head(inst);
+}
+
+
+/**
+ * Initialize builtin variables with values based on other builtin variables.
+ * These are initialized in the main function.
+ */
+void
+_mesa_glsl_initialize_derived_variables(gl_shader *shader)
+{
+ /* We only need to set CS variables currently. */
+ if (shader->Stage != MESA_SHADER_COMPUTE)
+ return;
+
+ ir_function_signature *const main_sig =
+ _mesa_get_main_function_signature(shader);
+ if (main_sig == NULL)
+ return;
+
+ initialize_cs_derived_variables(shader, main_sig);
+}