These intrinsics exist in icc. They can be found on the Intel Intrinsics Guide website.
All the backend support is in place to pattern match a load+bswap or a bswap+store pattern to the MOVBE instructions. So we just need to get the frontend to emit the correct IR. The pointer arguments in icc are declared as void so I had to jump through a packed struct to forcing a specific alignment on the load/store. Same trick we use in the unaligned vector load/store intrinsics
Differential Revision: https://reviews.llvm.org/D52586
llvm-svn: 343343
Craig Topper