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From: "arjun.is at lostca dot se" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/95185] Failure to optimize specific kind of
 sign comparison check
Date: Mon, 04 Oct 2021 23:02:38 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D95185

Arjun Shankar <arjun.is at lostca dot se> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |arjun.is at lostca dot se

--- Comment #3 from Arjun Shankar <arjun.is at lostca dot se> ---
If the code is compiled as C, gcc produces essentially the same code as cla=
ng
with some differences in the schedule of instructions:
https://godbolt.org/z/8nsq16Pen

It's when the code is compiled as C++ that gcc does worse:
https://godbolt.org/z/dK8hTEhjr

The difference lies in the front-ends. The C front-end already appears to k=
now
that this is a XOR. testcase.c.004t.original looks like:

  return (int) (x < 0 ^ y <=3D 0);

On the other hand, g++ outputs:

  return <retval> =3D x >=3D 0 =3D=3D y <=3D 0;=