vsk added inline comments.
================ Comment at: compiler-rt/test/ubsan/TestCases/Integer/unsigned-shift.cpp:6 + volatile unsigned _v = (val); \ + volatile unsigned _a = (amount); \ + unsigned res = _v << _a; \ ---------------- jfb wrote: > vsk wrote: > > Does the test not work without the volatiles? > It seems that LLVM sees too much without volatile, yes. The optimizer isn't running. Perhaps this is necessary because clang's constant folder kicks in? ================ Comment at: llvm/docs/ReleaseNotes.rst:151 + +One can silence the check with masking, for example: + ---------------- This could use some more explanation, maybe s/with masking/by clearing bits that would be shifted out/? ================ Comment at: llvm/docs/ReleaseNotes.rst:153 + + `(lhs & ~(~1U << ((sizeof(lhs)*CHAR_BIT) - rhs))) << rhs` + ---------------- jfb wrote: > lebedev.ri wrote: > > Surely not `~1U`. > Indeed, fixed. I don't think this pattern works when rhs = 0 (https://godbolt.org/z/rvEGqh). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D86000/new/ https://reviews.llvm.org/D86000 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
