tree cae5e3ae000ef24045c8d7268085f83e45598a50
parent 832984ded28f3095e33164af5c159f97b79b47c7
author Justin Lebar <jlebar@google.com> 1520441809 +0000
committer Justin Lebar <jlebar@google.com> 1520441809 +0000

Re-land: Teach CorrelatedValuePropagation to reduce the width of udiv/urem instructions.

Summary:
If the operands of a udiv/urem can be proved to fit within a smaller
power-of-two-sized type, reduce the width of the udiv/urem.

Backed out for failing an assert in clang bootstrap builds.  Re-landing
with a fix for handling non-power-of-two inputs (e.g. udiv i24).

Original Differential Revision: https://reviews.llvm.org/D44102

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326908 91177308-0d34-0410-b5e6-96231b3b80d8