tree 62f4025df2866dcfe137a5ab45dfa4db401bb0e2
parent 2b0c82a99f57f3314f5a97692791a9e5767bdf72
author Nikita Popov <nikita.ppv@gmail.com> 1571602782 +0000
committer Nikita Popov <nikita.ppv@gmail.com> 1571602782 +0000

[InstCombine] Fold uadd.sat(a, b) == 0 and usub.sat(a, b) == 0

This adds folds for comparing uadd.sat/usub.sat with zero:

 * uadd.sat(a, b) == 0 => a == 0 && b == 0 => (a | b) == 0
 * usub.sat(a, b) == 0 => a <= b

And inverted forms for !=.

Differential Revision: https://reviews.llvm.org/D69224

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375374 91177308-0d34-0410-b5e6-96231b3b80d8