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Implement HIR conversion for ?: operator

This commit is contained in:
Ian Romanick 2010-03-29 15:33:54 -07:00
parent 5185a5f7d5
commit 96f9cea116
1 changed files with 63 additions and 1 deletions
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64
ast_to_hir.cpp
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@ -699,8 +699,70 @@ ast_expression::hir(exec_list *instructions,
case ast_or_assign:
break;
case ast_conditional:
case ast_conditional: {
op[0] = this->subexpressions[0]->hir(instructions, state);
/* From page 59 (page 65 of the PDF) of the GLSL 1.50 spec:
*
* "The ternary selection operator (?:). It operates on three
* expressions (exp1 ? exp2 : exp3). This operator evaluates the
* first expression, which must result in a scalar Boolean."
*/
if (!op[0]->type->is_boolean() || !op[0]->type->is_scalar()) {
YYLTYPE loc = this->subexpressions[0]->get_location();
_mesa_glsl_error(& loc, state, "?: condition must be scalar boolean");
error_emitted = true;
}
/* The :? operator is implemented by generating an anonymous temporary
* followed by an if-statement. The last instruction in each branch of
* the if-statement assigns a value to the anonymous temporary. This
* temporary is the r-value of the expression.
*/
ir_variable *const tmp = generate_temporary(glsl_type::error_type,
instructions, state);
ir_if *const stmt = new ir_if(op[0]);
instructions->push_tail(stmt);
op[1] = this->subexpressions[1]->hir(& stmt->then_instructions, state);
ir_dereference *const then_deref = new ir_dereference(tmp);
ir_assignment *const then_assign =
new ir_assignment(then_deref, op[1], NULL);
stmt->then_instructions.push_tail(then_assign);
op[2] = this->subexpressions[2]->hir(& stmt->else_instructions, state);
ir_dereference *const else_deref = new ir_dereference(tmp);
ir_assignment *const else_assign =
new ir_assignment(else_deref, op[2], NULL);
stmt->else_instructions.push_tail(else_assign);
/* From page 59 (page 65 of the PDF) of the GLSL 1.50 spec:
*
* "The second and third expressions can be any type, as
* long their types match, or there is a conversion in
* Section 4.1.10 "Implicit Conversions" that can be applied
* to one of the expressions to make their types match. This
* resulting matching type is the type of the entire
* expression."
*/
/* FINISHME: Apply implicit conversions */
if (op[1]->type == op[2]->type) {
tmp->type = op[1]->type;
} else {
YYLTYPE loc = this->subexpressions[1]->get_location();
_mesa_glsl_error(& loc, state, "Second and third operands of ?: "
"operator must have matching types.");
error_emitted = true;
}
result = new ir_dereference(tmp);
type = tmp->type;
break;
}
case ast_pre_inc:
case ast_pre_dec: {