[llvm-bugs] [Bug 48333] wrong code with "-inline -early-cse-memssa -simplifycfg -instcombine -loop-unroll"

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=48333

Florian Hahn <florian_hahn at apple.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|---                         |INVALID
                 CC|                            |florian_hahn at apple.com

--- Comment #1 from Florian Hahn <florian_hahn at apple.com> ---
I think the program contains at least 2 cases of UB (try -fsanitize=undefined).
d = -19:
* negative shift in `*f = (f == f) >> *f;`
* negative index for `c = b[d];`

I strongly suspect that is the source of the differences with optimizations. I
tried with d = 1 and the test produces consistent result. Please re-open in
case I missed something or if there's a non-UB version of the original program
that shows the issue.

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