This is PR37104.
PR6773 will introduce an IR canonicalization that is likely bad for the end assembly.
Previously, andl+andn/andps+andnps / bic/bsl would be generated. (see @out)
Now, they would no longer be generated (see @in).
I'm guessing llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp should be able to unfold this.
Not sure this RUN adds much value - I think SSE is required by the x86-64 ABI, so we may already be in undefined territory with these tests. :)
A target with -mattr=avx may be slightly more interesting, but there might not be enough ISA difference there to even make that worthwhile.