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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug tree-optimization/103063] [9/10/11/12 Regression] Wrong code
 while using -O3 since r7-2373-g69b806f6a60efcf1
Date: Wed, 19 Jan 2022 16:33:19 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103063

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Unless I'm missing something, the outer loop iterates with a =3D -6,
b is 0, so (unsigned char) (b-- * 6) is 0 (so the inner loop doesn't iterate
further) and b is decremented to 255.
Next a =3D a - 8 makes a =3D -14 out of that, so the outer loop doesn't ite=
rate any
longer, so abort is what the test should do (unless changed to b !=3D 255).=