https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124108
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |law at gcc dot gnu.org,
| |smunnangi1 at ventanamicro dot
com
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
/* In this case the XOR flips bits that originate from the result of the
right shift and do not impact the result of the left shift. We can
reassociate the XOR to work on the final result and simplify the rest
to a rotate. */
(simplify
(bit_ior:c (lshift @0 INTEGER_CST@1)
(bit_xor (rshift @2 INTEGER_CST@3) INTEGER_CST@4))
(if (tree_fits_uhwi_p (@1)
&& tree_fits_uhwi_p (@3)
&& tree_fits_uhwi_p (@4)
&& ((~((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 (tree_fits_uhwi_p (@1)
&& tree_fits_uhwi_p (@2)
&& tree_fits_uhwi_p (@4)
&& (((((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)))
These 2 patterns need `type_has_mode_precision_p (type)`.
