[PATCH] Simplify replace_trapping_overflow

[Richard Biener]

Bootstrap & regtest running on x86_64-unknown-linux-gnu.

Richard.

2018-10-30  Richard Biener  <rguent...@suse.de>

        * tree-eh.c (replace_trapping_overflow): Simplify ABS_EXPR case
        using ABSU_EXPR.

diff --git a/gcc/tree-eh.c b/gcc/tree-eh.c
index 1c7d9dc1d59..046405b8a15 100644
--- a/gcc/tree-eh.c
+++ b/gcc/tree-eh.c
@@ -2759,27 +2759,9 @@ replace_trapping_overflow (tree *tp, int *walk_subtrees, 
void *data)
 
       if (TREE_CODE (*tp) == ABS_EXPR)
        {
-         tree op = TREE_OPERAND (*tp, 0);
-         op = save_expr (op);
-         /* save_expr skips simple arithmetics, which is undesirable
-            here, if it might trap due to flag_trapv.  We need to
-            force a SAVE_EXPR in the COND_EXPR condition, to evaluate
-            it before the comparison.  */
-         if (EXPR_P (op)
-             && TREE_CODE (op) != SAVE_EXPR
-             && walk_tree (&op, find_trapping_overflow, NULL, NULL))
-           {
-             op = build1_loc (EXPR_LOCATION (op), SAVE_EXPR, type, op);
-             TREE_SIDE_EFFECTS (op) = 1;
-           }
-         /* Change abs (op) to op < 0 ? -op : op and handle the NEGATE_EXPR
-            like other signed integer trapping operations.  */
-         tree cond = fold_build2 (LT_EXPR, boolean_type_node,
-                                  op, build_int_cst (type, 0));
-         tree neg = fold_build1 (NEGATE_EXPR, utype,
-                                 fold_convert (utype, op));
-         *tp = fold_build3 (COND_EXPR, type, cond,
-                            fold_convert (type, neg), op);
+         TREE_SET_CODE (*tp, ABSU_EXPR);
+         TREE_TYPE (*tp, utype);
+         *tp = fold_convert (type, *tp);
        }
       else
        {