tstellarAMD added a subscriber: tstellarAMD. tstellarAMD added a comment. You may need this for non-clang frontends, but for clang, you can mark memmove as unsupported in TargetLibraryInfo. This is what we do on AMDGPU for memcpy and memset. Repository: rL LLVM http://reviews.llvm.org/D11220