On 25 November 2015 at 17:19, Paolo Bonzini <pbonz...@redhat.com> wrote: > Ubsan also has warnings for undefined behavior of left shifts. Checks for > left shift overflow and left shift of negative numbers, unfortunately, > cannot be silenced without also silencing the useful ones about out-of-range > shift amounts. -fwrapv ought to shut them up, but doesn't yet > (https://llvm.org/bugs/show_bug.cgi?id=25552; I am taking care of fixing > the same issues in GCC). Luckily ubsan is optional, and the easy > workaround is to use -fsanitize-recover.
We still haven't had any response from the LLVM/clang folks that this interpretation of the meaning of -fwrapv is their interpretation of it, have we? (I can't see any comments on the referenced bug.) thanks -- PMM
