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[IndVars] Widen more comparisons for non-negative induction vars

Authored by sanjoy on Sep 18 2015, 2:21 PM.

Description

[IndVars] Widen more comparisons for non-negative induction vars

Summary:
If an induction variable is provably non-negative, its sign extension is
equal to its zero extension. This means narrow uses like

icmp slt iNarrow %indvar, %rhs

can be widened into

icmp slt iWide zext(%indvar), sext(%rhs)

Reviewers: atrick, mcrosier, hfinkel

Subscribers: hfinkel, reames, llvm-commits

Differential Revision: http://reviews.llvm.org/D12745

llvm-svn: 248045

Details

Committed
sanjoySep 18 2015, 2:21 PM
Differential Revision
D12745: [IndVars] Widen more comparisons for non-negative induction vars.
Parents
rGe8d1c59756d9: Style fix to make it look consistent. NFC.
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