#include "ir_visitor.h"
#include "ir_optimization.h"
#include "glsl_types.h"
+#include "main/macros.h"
/**
* Visitor class for replacing expressions with ir_constant values.
*/
+namespace {
+
class ir_vec_index_to_swizzle_visitor : public ir_hierarchical_visitor {
public:
ir_vec_index_to_swizzle_visitor()
progress = false;
}
- ir_rvalue *convert_vec_index_to_swizzle(ir_rvalue *val);
+ ir_rvalue *convert_vector_extract_to_swizzle(ir_rvalue *val);
virtual ir_visitor_status visit_enter(ir_expression *);
virtual ir_visitor_status visit_enter(ir_swizzle *);
bool progress;
};
+} /* anonymous namespace */
+
ir_rvalue *
-ir_vec_index_to_swizzle_visitor::convert_vec_index_to_swizzle(ir_rvalue *ir)
+ir_vec_index_to_swizzle_visitor::convert_vector_extract_to_swizzle(ir_rvalue *ir)
{
- ir_dereference_array *deref = ir->as_dereference_array();
- ir_constant *ir_constant;
-
- if (!deref)
- return ir;
-
- if (deref->array->type->is_matrix() || deref->array->type->is_array())
+ ir_expression *const expr = ir->as_expression();
+ if (expr == NULL || expr->operation != ir_binop_vector_extract)
return ir;
- assert(deref->array_index->type->base_type == GLSL_TYPE_INT);
- ir_constant = deref->array_index->constant_expression_value();
- if (!ir_constant)
+ ir_constant *const idx = expr->operands[1]->constant_expression_value();
+ if (idx == NULL)
return ir;
void *ctx = ralloc_parent(ir);
this->progress = true;
- return new(ctx) ir_swizzle(deref->array,
- ir_constant->value.i[0], 0, 0, 0, 1);
+
+ /* Page 40 of the GLSL 1.20 spec says:
+ *
+ * "When indexing with non-constant expressions, behavior is undefined
+ * if the index is negative, or greater than or equal to the size of
+ * the vector."
+ *
+ * The quoted spec text mentions non-constant expressions, but this code
+ * operates on constants. These constants are the result of non-constant
+ * expressions that have been optimized to constants. The common case here
+ * is a loop counter from an unrolled loop that is used to index a vector.
+ *
+ * The ir_swizzle constructor gets angry if the index is negative or too
+ * large. For simplicity sake, just clamp the index to [0, size-1].
+ */
+ const int i = CLAMP(idx->value.i[0], 0,
+ (int) expr->operands[0]->type->vector_elements - 1);
+
+ return new(ctx) ir_swizzle(expr->operands[0], i, 0, 0, 0, 1);
}
ir_visitor_status
unsigned int i;
for (i = 0; i < ir->get_num_operands(); i++) {
- ir->operands[i] = convert_vec_index_to_swizzle(ir->operands[i]);
+ ir->operands[i] = convert_vector_extract_to_swizzle(ir->operands[i]);
}
return visit_continue;
* the result of indexing a vector is. But maybe at some point we'll end up
* using swizzling of scalars for vector construction.
*/
- ir->val = convert_vec_index_to_swizzle(ir->val);
+ ir->val = convert_vector_extract_to_swizzle(ir->val);
return visit_continue;
}
ir_visitor_status
ir_vec_index_to_swizzle_visitor::visit_enter(ir_assignment *ir)
{
- ir->set_lhs(convert_vec_index_to_swizzle(ir->lhs));
- ir->rhs = convert_vec_index_to_swizzle(ir->rhs);
+ ir->rhs = convert_vector_extract_to_swizzle(ir->rhs);
return visit_continue;
}
ir_visitor_status
ir_vec_index_to_swizzle_visitor::visit_enter(ir_call *ir)
{
- foreach_iter(exec_list_iterator, iter, *ir) {
- ir_rvalue *param = (ir_rvalue *)iter.get();
- ir_rvalue *new_param = convert_vec_index_to_swizzle(param);
+ foreach_in_list_safe(ir_rvalue, param, &ir->actual_parameters) {
+ ir_rvalue *new_param = convert_vector_extract_to_swizzle(param);
if (new_param != param) {
param->replace_with(new_param);
ir_vec_index_to_swizzle_visitor::visit_enter(ir_return *ir)
{
if (ir->value) {
- ir->value = convert_vec_index_to_swizzle(ir->value);
+ ir->value = convert_vector_extract_to_swizzle(ir->value);
}
return visit_continue;
ir_visitor_status
ir_vec_index_to_swizzle_visitor::visit_enter(ir_if *ir)
{
- ir->condition = convert_vec_index_to_swizzle(ir->condition);
+ ir->condition = convert_vector_extract_to_swizzle(ir->condition);
return visit_continue;
}