http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59660
--- Comment #9 from Jan Hubicka <hubicka at ucw dot cz> ---
Hi,
this patch solves the testcase.
The first hunk gets rid of the redundant NOP_EXPR converting TRUTH_EXPR from
INT to BOOL. The second improves gimplifier to not introduce unnecesary
control flow.
If this approach seems to make sense, I will extend it to other booleans and
prepare less hackish patch.
Honza
Index: fold-const.c
===================================================================
--- fold-const.c (revision 206346)
+++ fold-const.c (working copy)
@@ -1977,6 +1977,8 @@ fold_convert_loc (location_t loc, tree t
case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
case OFFSET_TYPE:
+ if (TREE_CODE (arg) == TRUTH_ORIF_EXPR)
+ return fold_build2_loc (loc, TRUTH_ORIF_EXPR, type, TREE_OPERAND (arg, 0),
TREE_OPERAND (arg, 1));
if (TREE_CODE (arg) == INTEGER_CST)
{
tem = fold_convert_const (NOP_EXPR, type, arg);
Index: gimplify.c
===================================================================
--- gimplify.c (revision 206346)
+++ gimplify.c (working copy)
@@ -2931,14 +2931,37 @@ gimplify_cond_expr (tree *expr_p, gimple
result = build_simple_mem_ref_loc (loc, tmp);
}
- /* Build the new then clause, `tmp = then_;'. But don't build the
- assignment if the value is void; in C++ it can be if it's a throw. */
- if (!VOID_TYPE_P (TREE_TYPE (then_)))
- TREE_OPERAND (expr, 1) = build2 (MODIFY_EXPR, type, tmp, then_);
+ /* Convert (A||B) ? true : false
+ as A ? tmp = true : tmp = B != 0. */
- /* Similarly, build the new else clause, `tmp = else_;'. */
- if (!VOID_TYPE_P (TREE_TYPE (else_)))
- TREE_OPERAND (expr, 2) = build2 (MODIFY_EXPR, type, tmp, else_);
+ if (integer_zerop (else_) && integer_onep (then_)
+ && TREE_CODE (TREE_OPERAND (expr, 0)) == TRUTH_ORIF_EXPR)
+ {
+ tree pred = TREE_OPERAND (expr, 0);
+ location_t loc = EXPR_LOCATION (*expr_p);
+ TREE_OPERAND (expr, 0) = TREE_OPERAND (pred, 0);
+ /* Build the new then clause, `tmp = then_;'. But don't build the
+ assignment if the value is void; in C++ it can be if it's a throw.
*/
+ TREE_OPERAND (expr, 1) = build2 (MODIFY_EXPR, type, tmp,
+ fold_convert (type, boolean_true_node));
+
+ /* Similarly, build the new else clause, `tmp = else_;'. */
+ TREE_OPERAND (expr, 2) = build2 (MODIFY_EXPR, type, tmp,
+ fold_build2_loc (loc, NE_EXPR, type, TREE_OPERAND
(pred, 1),
+ fold_convert (TREE_TYPE (TREE_OPERAND (pred,
1)),
+ integer_zero_node)));
+ }
+ else
+ {
+ /* Build the new then clause, `tmp = then_;'. But don't build the
+ assignment if the value is void; in C++ it can be if it's a throw.
*/
+ if (!VOID_TYPE_P (TREE_TYPE (then_)))
+ TREE_OPERAND (expr, 1) = build2 (MODIFY_EXPR, type, tmp, then_);
+
+ /* Similarly, build the new else clause, `tmp = else_;'. */
+ if (!VOID_TYPE_P (TREE_TYPE (else_)))
+ TREE_OPERAND (expr, 2) = build2 (MODIFY_EXPR, type, tmp, else_);
+ }
TREE_TYPE (expr) = void_type_node;
recalculate_side_effects (expr);
