[InstCombine] Canonicalize icmp instructions based on dominating conditions.
Summary:
This patch canonicalizes conditions based on the constant range information
of the dominating branch condition.
For example:
%cmp = icmp slt i64 %a, 0
br i1 %cmp, label %land.lhs.true, label %lor.rhs
lor.rhs:
%cmp2 = icmp sgt i64 %a, 0
Would now be canonicalized into:
%cmp = icmp slt i64 %a, 0
br i1 %cmp, label %land.lhs.true, label %lor.rhs
lor.rhs:
%cmp2 = icmp ne i64 %a, 0
Reviewers: mcrosier, gberry, t.p.northover, llvm-commits, reames, hfinkel, sanjoy, majnemer
Subscribers: MatzeB, majnemer, mcrosier
Differential Revision: http://reviews.llvm.org/D18841
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@268521 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed