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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug sanitizer/115156] [14/15 Regression] passing zero to
 __builtin_clzl() check missing
Date: Sun, 19 May 2024 15:14:34 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D115156

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

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

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r14-1880-g827e208fa64771f15fc8e53970a2297e637277b5
Note, the functions in question are const, so they can be dead code elimina=
ted
at any time, and the UBSAN instrumentation in this case is done only in the
ubsan pass, so if it gets folded away before that it won't be instrumented.
At -O1 or higher it would be a clear non-bug, with optimizations sanitizers
often diagnose only UB in code that isn't dead, in this case a question is =
why
we are folding this at -O0.=