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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/94911] Failure to optimize comparisons of VLA
 sizes
Date: Fri, 01 May 2020 22:21:13 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94911

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Marc Glisse from comment #1)
> gcc computes sizeof(a) as 4ul*(size_t)n, and unsigned types don't provide
> nice overflow guarantees, so that complicates things.

While the C++ front-end does:
(sizetype) ((ssizetype) n + -1) + 1) * 4)=