https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96702
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The pattern:
/* X - Y < X is the same as Y > 0 when there is no overflow.
For equality, this is also true with wrapping overflow. */
(for op (simple_comparison)
(simplify
(op:c @0 (minus@2 @0 @1))
(if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
&& (TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))
|| ((op == EQ_EXPR || op == NE_EXPR)
&& TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))))
&& (CONSTANT_CLASS_P (@1) || single_use (@2)))
(op @1 { build_zero_cst (TREE_TYPE (@1)); }))))
https://gcc.gnu.org/pipermail/gcc-patches/2017-October/484606.html describes
why there was a single use but I wonder if ranger now does not cause the need
for the single_use ....
