+ir_rvalue *
+ast_switch_statement::hir(exec_list *instructions,
+ struct _mesa_glsl_parse_state *state)
+{
+ void *ctx = state;
+
+ ir_rvalue *const test_expression =
+ this->test_expression->hir(instructions, state);
+
+ /* From page 66 (page 55 of the PDF) of the GLSL 1.50 spec:
+ *
+ * "The type of init-expression in a switch statement must be a
+ * scalar integer."
+ */
+ if (!test_expression->type->is_scalar() ||
+ !test_expression->type->is_integer()) {
+ YYLTYPE loc = this->test_expression->get_location();
+
+ _mesa_glsl_error(& loc,
+ state,
+ "switch-statement expression must be scalar "
+ "integer");
+ }
+
+ /* Track the switch-statement nesting in a stack-like manner.
+ */
+ struct glsl_switch_state saved = state->switch_state;
+
+ state->switch_state.is_switch_innermost = true;
+ state->switch_state.switch_nesting_ast = this;
+ state->switch_state.labels_ht = hash_table_ctor(0, hash_table_pointer_hash,
+ hash_table_pointer_compare);
+ state->switch_state.previous_default = NULL;
+
+ /* Initalize is_fallthru state to false.
+ */
+ ir_rvalue *const is_fallthru_val = new (ctx) ir_constant(false);
+ state->switch_state.is_fallthru_var =
+ new(ctx) ir_variable(glsl_type::bool_type,
+ "switch_is_fallthru_tmp",
+ ir_var_temporary);
+ instructions->push_tail(state->switch_state.is_fallthru_var);
+
+ ir_dereference_variable *deref_is_fallthru_var =
+ new(ctx) ir_dereference_variable(state->switch_state.is_fallthru_var);
+ instructions->push_tail(new(ctx) ir_assignment(deref_is_fallthru_var,
+ is_fallthru_val));
+
+ /* Initalize is_break state to false.
+ */
+ ir_rvalue *const is_break_val = new (ctx) ir_constant(false);
+ state->switch_state.is_break_var = new(ctx) ir_variable(glsl_type::bool_type,
+ "switch_is_break_tmp",
+ ir_var_temporary);
+ instructions->push_tail(state->switch_state.is_break_var);
+
+ ir_dereference_variable *deref_is_break_var =
+ new(ctx) ir_dereference_variable(state->switch_state.is_break_var);
+ instructions->push_tail(new(ctx) ir_assignment(deref_is_break_var,
+ is_break_val));
+
+ /* Cache test expression.
+ */
+ test_to_hir(instructions, state);
+
+ /* Emit code for body of switch stmt.
+ */
+ body->hir(instructions, state);
+
+ hash_table_dtor(state->switch_state.labels_ht);
+
+ state->switch_state = saved;
+
+ /* Switch statements do not have r-values. */
+ return NULL;
+}
+
+
+void
+ast_switch_statement::test_to_hir(exec_list *instructions,
+ struct _mesa_glsl_parse_state *state)
+{
+ void *ctx = state;
+
+ /* Cache value of test expression. */
+ ir_rvalue *const test_val =
+ test_expression->hir(instructions,
+ state);
+
+ state->switch_state.test_var = new(ctx) ir_variable(test_val->type,
+ "switch_test_tmp",
+ ir_var_temporary);
+ ir_dereference_variable *deref_test_var =
+ new(ctx) ir_dereference_variable(state->switch_state.test_var);
+
+ instructions->push_tail(state->switch_state.test_var);
+ instructions->push_tail(new(ctx) ir_assignment(deref_test_var, test_val));
+}
+
+
+ir_rvalue *
+ast_switch_body::hir(exec_list *instructions,
+ struct _mesa_glsl_parse_state *state)
+{
+ if (stmts != NULL)
+ stmts->hir(instructions, state);
+
+ /* Switch bodies do not have r-values. */
+ return NULL;
+}
+
+ir_rvalue *
+ast_case_statement_list::hir(exec_list *instructions,
+ struct _mesa_glsl_parse_state *state)
+{
+ foreach_list_typed (ast_case_statement, case_stmt, link, & this->cases)
+ case_stmt->hir(instructions, state);
+
+ /* Case statements do not have r-values. */
+ return NULL;
+}
+
+ir_rvalue *
+ast_case_statement::hir(exec_list *instructions,
+ struct _mesa_glsl_parse_state *state)
+{
+ labels->hir(instructions, state);
+
+ /* Conditionally set fallthru state based on break state. */
+ ir_constant *const false_val = new(state) ir_constant(false);
+ ir_dereference_variable *const deref_is_fallthru_var =
+ new(state) ir_dereference_variable(state->switch_state.is_fallthru_var);
+ ir_dereference_variable *const deref_is_break_var =
+ new(state) ir_dereference_variable(state->switch_state.is_break_var);
+ ir_assignment *const reset_fallthru_on_break =
+ new(state) ir_assignment(deref_is_fallthru_var,
+ false_val,
+ deref_is_break_var);
+ instructions->push_tail(reset_fallthru_on_break);
+
+ /* Guard case statements depending on fallthru state. */
+ ir_dereference_variable *const deref_fallthru_guard =
+ new(state) ir_dereference_variable(state->switch_state.is_fallthru_var);
+ ir_if *const test_fallthru = new(state) ir_if(deref_fallthru_guard);
+
+ foreach_list_typed (ast_node, stmt, link, & this->stmts)
+ stmt->hir(& test_fallthru->then_instructions, state);
+
+ instructions->push_tail(test_fallthru);
+
+ /* Case statements do not have r-values. */
+ return NULL;
+}
+
+
+ir_rvalue *
+ast_case_label_list::hir(exec_list *instructions,
+ struct _mesa_glsl_parse_state *state)
+{
+ foreach_list_typed (ast_case_label, label, link, & this->labels)
+ label->hir(instructions, state);
+
+ /* Case labels do not have r-values. */
+ return NULL;
+}
+
+ir_rvalue *
+ast_case_label::hir(exec_list *instructions,
+ struct _mesa_glsl_parse_state *state)
+{
+ void *ctx = state;
+
+ ir_dereference_variable *deref_fallthru_var =
+ new(ctx) ir_dereference_variable(state->switch_state.is_fallthru_var);
+
+ ir_rvalue *const true_val = new(ctx) ir_constant(true);
+
+ /* If not default case, ... */
+ if (this->test_value != NULL) {
+ /* Conditionally set fallthru state based on
+ * comparison of cached test expression value to case label.
+ */
+ ir_rvalue *const label_rval = this->test_value->hir(instructions, state);
+ ir_constant *label_const = label_rval->constant_expression_value();
+
+ if (!label_const) {
+ YYLTYPE loc = this->test_value->get_location();
+
+ _mesa_glsl_error(& loc, state,
+ "switch statement case label must be a "
+ "constant expression");
+
+ /* Stuff a dummy value in to allow processing to continue. */
+ label_const = new(ctx) ir_constant(0);
+ } else {
+ ast_expression *previous_label = (ast_expression *)
+ hash_table_find(state->switch_state.labels_ht,
+ (void *)(uintptr_t)label_const->value.u[0]);
+
+ if (previous_label) {
+ YYLTYPE loc = this->test_value->get_location();
+ _mesa_glsl_error(& loc, state,
+ "duplicate case value");
+
+ loc = previous_label->get_location();
+ _mesa_glsl_error(& loc, state,
+ "this is the previous case label");
+ } else {
+ hash_table_insert(state->switch_state.labels_ht,
+ this->test_value,
+ (void *)(uintptr_t)label_const->value.u[0]);
+ }
+ }
+
+ ir_dereference_variable *deref_test_var =
+ new(ctx) ir_dereference_variable(state->switch_state.test_var);
+
+ ir_rvalue *const test_cond = new(ctx) ir_expression(ir_binop_all_equal,
+ label_const,
+ deref_test_var);
+
+ ir_assignment *set_fallthru_on_test =
+ new(ctx) ir_assignment(deref_fallthru_var,
+ true_val,
+ test_cond);
+
+ instructions->push_tail(set_fallthru_on_test);
+ } else { /* default case */
+ if (state->switch_state.previous_default) {
+ YYLTYPE loc = this->get_location();
+ _mesa_glsl_error(& loc, state,
+ "multiple default labels in one switch");
+
+ loc = state->switch_state.previous_default->get_location();
+ _mesa_glsl_error(& loc, state,
+ "this is the first default label");
+ }
+ state->switch_state.previous_default = this;
+
+ /* Set falltrhu state. */
+ ir_assignment *set_fallthru =
+ new(ctx) ir_assignment(deref_fallthru_var, true_val);
+
+ instructions->push_tail(set_fallthru);
+ }
+
+ /* Case statements do not have r-values. */
+ return NULL;
+}
+