| commit | e15387964886dcb3d919648218da958f9707d988 | |
| author | James Molloy <james.molloy@arm.com> | |
| Fri, 11 Dec 2015 10:04:51 +0000 (11 10:04 +0000) | ||
| committer | James Molloy <james.molloy@arm.com> | |
| Fri, 11 Dec 2015 10:04:51 +0000 (11 10:04 +0000) | ||
| tree | c2dab2e9c31086e69909ee97613a8475b19446de | treesnapshot (tar.gz zip) |
| parent | 11663248fea4f05ded465b0d7c03c8bfb2772af8 | commitdiff |
[InstCombine] Make MatchBSwap also match bit reversals
MatchBSwap has most of the functionality to match bit reversals already. If we switch it from looking at bytes to individual bits and remove a few early exits, we can extend the main recursive function to match any sequence of ORs, ANDs and shifts that assemble a value from different parts of another, base value. Once we have this bit->bit mapping, we can very simply detect if it is appropriate for a bswap or bitreverse.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255334 91177308-0d34-0410-b5e6-96231b3b80d8
MatchBSwap has most of the functionality to match bit reversals already. If we switch it from looking at bytes to individual bits and remove a few early exits, we can extend the main recursive function to match any sequence of ORs, ANDs and shifts that assemble a value from different parts of another, base value. Once we have this bit->bit mapping, we can very simply detect if it is appropriate for a bswap or bitreverse.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255334 91177308-0d34-0410-b5e6-96231b3b80d8