https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123530
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |ASSIGNED
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The match patterns:
```
(simplify
(bit_ior:c (lshift @0 INTEGER_CST@1)
(bit_xor (rshift @2 INTEGER_CST@3) INTEGER_CST@4))
(if (((~((HOST_WIDE_INT_1U << tree_to_uhwi (@1)) - 1)) & tree_to_uhwi (@4))
== 0
&& (tree_to_uhwi (@1) + tree_to_uhwi (@3)) == TYPE_PRECISION (type)
&& TYPE_UNSIGNED (type)
&& @0 == @2)
(bit_xor (rrotate @0 @3) @4)))
/* Similarly, but in this case the XOR flips bits that originate from the
result of the left shift. */
(simplify
(bit_ior:c (bit_xor (lshift @0 INTEGER_CST@1) INTEGER_CST@2)
(rshift @3 INTEGER_CST@4))
(if ((((((HOST_WIDE_INT_1U << tree_to_uhwi (@1)) - 1)) & tree_to_uhwi (@2))
== 0)
&& (tree_to_uhwi (@1) + tree_to_uhwi (@4)) == TYPE_PRECISION (type)
&& TYPE_UNSIGNED (type)
&& @0 == @3)
(bit_xor (rrotate @0 @4) @2)))
```
Assume the shift's rhs was in the defined range. But in this case it is -1
signed int which is not well defined range.
