Did a test build of the 0.12 RC with mingw-w64 on GCC-8.2.0, getting: Build error: '_mm_crc32_u64' was not declared in this scope. Full log: https://ci.appveyor.com/project/jeroen/rtools-packages/build/job/c619b6ibu1uqeqln
I'm not sure what this does but I would guess that you should be using _mm_crc32_u32 instead of _mm_crc32_u64 on 32bit (or disable SSE4 extensions all together)?
