2016-09-29 Richard Biener <rguenther@suse.de>
+ PR middle-end/77407
+ * match.pd: Add X / abs (X) -> X < 0 ? -1 : 1 and
+ X / -X -> -1 simplifications.
+
+2016-09-29 Richard Biener <rguenther@suse.de>
+
PR middle-end/55152
* match.pd: Add max(a,-a) -> abs(a) pattern.
* tree-ssa-phiopt.c (minmax_replacement): Disable for
(op @0 integer_onep)
(non_lvalue @0)))
-/* X / -1 is -X. */
(for div (trunc_div ceil_div floor_div round_div exact_div)
+ /* X / -1 is -X. */
(simplify
(div @0 integer_minus_onep@1)
(if (!TYPE_UNSIGNED (type))
- (negate @0))))
+ (negate @0)))
+ /* X / abs (X) is X < 0 ? -1 : 1. */
+ (simplify
+ (div @0 (abs @0))
+ (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
+ && TYPE_OVERFLOW_UNDEFINED (type))
+ (cond (lt @0 { build_zero_cst (type); })
+ { build_minus_one_cst (type); } { build_one_cst (type); })))
+ /* X / -X is -1. */
+ (simplify
+ (div @0 (negate @0))
+ (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
+ && TYPE_OVERFLOW_UNDEFINED (type))
+ { build_minus_one_cst (type); })))
/* For unsigned integral types, FLOOR_DIV_EXPR is the same as
TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
--- /dev/null
+/* { dg-do compile } */
+/* { dg-options "-O -fstrict-overflow -fdump-tree-gimple" } */
+
+int foo (int c)
+{
+ if (c != 0)
+ c /= __builtin_abs (c);
+ return c;
+}
+
+int bar (int c)
+{
+ if (c != 0)
+ c /= -c;
+ return c;
+}
+
+/* { dg-final { scan-tree-dump-times "/" 0 "gimple" } } */