search for: matchbswaphwordlow

...l, the tests from https://reviews.llvm.org/rL133503 are still in the tree. I looked at those, but none of them include the full pattern that decomposes into bswap and rol. I debugged through the X86 bswap.ll test and verified none of those cases make it through MatchBSwapHWord (they get handled in MatchBSwapHWordLow instead). >> I don't think there is any existing code to match this particular pattern in instcombine. I guess it wouldn't be hard to add, though. Yes, I guess the InstCombiner::MatchBSwap() function is very similar but not identical. It looks for patterns that match the bswap exac...

I’m looking into problems with the function DAGCombiner::MatchBSwapHWord and had a couple questions on how to proceed (I’m new here, and to llvm). It looks like there was never any test coverage for this code, and it doesn’t match the patterns it claims to be looking for. I found a fix for this in our fork, but the fix is even worse in that it matches a whole bunch of invalid patterns as well as