tree ca6d2e866feaecfdd1da150740c7b0d0aeeabf69
parent f237196b1b443088a357fed5435082990b9794c8
author Sanjay Patel <spatel@rotateright.com> 1550764908 +0000
committer Sanjay Patel <spatel@rotateright.com> 1550764908 +0000

[DAGCombiner] prevent infinite looping by truncating 'and' (PR40793)

This fold can occur during legalization, so it can fight with promotion
to the larger type. It apparently takes a special sequence and subtarget
to avoid more basic simplifications that would hide the problem.

But there's a bigger question raised here: why does distributeTruncateThroughAnd()
even exist? It duplicates functionality from a more minimal pattern that we
already have. But getting rid of this function requires some preliminary steps.

https://bugs.llvm.org/show_bug.cgi?id=40793

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354594 91177308-0d34-0410-b5e6-96231b3b80d8