[PATCH] D118317: [InstCombine] Fold and-reduce idiom

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev created this revision.
mkazantsev added reviewers: spatel, nikic, greened, RKSimon, dmakogon.
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This patch introduces folding of add-reduce idiom and generates code
that is easier to read and which is lest costly in terms of icmp operations.
The folding is

  icmp eq (bitcast(icmp ne (lhs, rhs)), 0)

into

  icmp eq(bitcast(lhs), bitcast(rhs))


https://reviews.llvm.org/D118317

Files:
  llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
  llvm/test/Transforms/InstCombine/icmp-vec.ll
  llvm/test/Transforms/InstCombine/reduction-and-sext-zext-i1.ll
  llvm/test/Transforms/InstCombine/reduction-or-sext-zext-i1.ll

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