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There are 2 parts to this patch made simultaneously to avoid a regression. We're reversing the canonicalization that moves bitwise vector ops before bitcasts. We're moving bitwise vector ops *after* bitcasts instead. That's the 1st and 3rd hunks of the patch. The motivation is that there's only one fold that currently depends on the existing canonicalization (see next), but there are many folds that would automatically benefit from the new canonicalization. PR33138 ( https://bugs.llvm.org/show_bug.cgi?id=33138 ) shows why/how we have these patterns in IR. There's an or(and,andn) pattern that requires an adjustment in order to continue matching to 'select' because the bitcast changes position. This match is unfortunately complicated because it requires 4 logic ops with optional bitcast and sext ops. Test diffs: 1. The bitcast.ll and bitcast-bigendian.ll changes show the most basic difference - bitcast comes before logic. 2. There are also tests with no diffs in bitcast.ll that verify that we're still doing folds that were enabled by the previous canonicalization. 3. icmp-xor-signbit.ll shows the payoff. We don't need to adjust existing icmp patterns to look through bitcasts. 4. logical-select.ll contains several tests for the or(and,andn) --> select fold to verify that we are still handling those cases. The lone diff shows the movement of the bitcast from the new canonicalization rule. Differential Revision: https://reviews.llvm.org/D33517 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306011 91177308-0d34-0410-b5e6-96231b3b80d8
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