- /* If-statements can be either 'if (expr)' or 'if (deref)'. We only care
- * about the former here.
- */
- ir_expression *cond = if_stmt->condition->as_expression();
- if (cond == NULL)
- continue;
-
- switch (cond->operation) {
- case ir_binop_less:
- case ir_binop_greater:
- case ir_binop_lequal:
- case ir_binop_gequal: {
- /* The expressions that we care about will either be of the form
- * 'counter < limit' or 'limit < counter'. Figure out which is
- * which.
- */
- ir_rvalue *counter = cond->operands[0]->as_dereference_variable();
- ir_constant *limit = cond->operands[1]->as_constant();
- enum ir_expression_operation cmp = cond->operation;
-
- if (limit == NULL) {
- counter = cond->operands[1]->as_dereference_variable();
- limit = cond->operands[0]->as_constant();
-
- switch (cmp) {
- case ir_binop_less: cmp = ir_binop_gequal; break;
- case ir_binop_greater: cmp = ir_binop_lequal; break;
- case ir_binop_lequal: cmp = ir_binop_greater; break;
- case ir_binop_gequal: cmp = ir_binop_less; break;
- default: assert(!"Should not get here.");
- }
- }
-
- if ((counter == NULL) || (limit == NULL))
- break;
-
- ir_variable *var = counter->variable_referenced();
-
- ir_rvalue *init = find_initial_value(ir, var);
-
- foreach_list(iv_node, &ls->induction_variables) {
- loop_variable *lv = (loop_variable *) iv_node;
-
- if (lv->var == var) {
- const int iterations = calculate_iterations(init, limit,
- lv->increment,
- cmp);
- if (iterations >= 0) {
- /* If the new iteration count is lower than the previously
- * believed iteration count, update the loop control values.
- */
- if (iterations < max_iterations) {
- ir->from = init->clone(ir, NULL);
- ir->to = limit->clone(ir, NULL);
- ir->increment = lv->increment->clone(ir, NULL);
- ir->counter = lv->var;
- ir->cmp = cmp;
-
- max_iterations = iterations;
- }
-
- /* Remove the conditional break statement. The loop
- * controls are now set such that the exit condition will be
- * satisfied.
- */
- if_stmt->remove();
-
- assert(ls->num_loop_jumps > 0);
- ls->num_loop_jumps--;
-
- this->progress = true;
- }
-
- break;
- }
- }
- break;
- }
-
- default:
- break;