[Bug rtl-optimization/110701] [14 Regression] Wrong code at -O1/2/3/s on x86_64-linux-gnu

[roger at nextmovesoftware dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110701

Roger Sayle <roger at nextmovesoftware dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |roger at nextmovesoftware dot com

--- Comment #5 from Roger Sayle <roger at nextmovesoftware dot com> ---
nonzero_bits ((reg:DI 92),SImode) is returning 340, so combine (or more
specifically simplify_and_const_int_1) believes that the AND (ZERO_EXTEND)
isn't unnecessary.  So it's the same nonzero_bits information that allows us to
turn the  XOR into IOR (in insn 16) that's incorrectly telling us the AND 340
(or AND 343, or ZERO_EXTEND) is unnecessary (in insn 17).