[PATCH] D12800: [ValueTracking] Teach isKnownNonZero about monotonically increasing PHIs

James Molloy via llvm-commits llvm-commits at lists.llvm.org
Thu Sep 24 10:21:17 PDT 2015


jmolloy added a comment.

> Adding the analogous case isKnownNonNegative (aka, using it to set the sign bit in computeKnownBits) would be a really good idea. An increasing induction variable starting at zero is pretty much the ideal canonical induction variable and we should exploit that.


It looks like this should already be handled in computeKnownBits (ValueTracking.cpp:1277).


Repository:
  rL LLVM

http://reviews.llvm.org/D12800





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