tree 53d8e9aad7c2707137b781b87842f82e3a52c61e
parent 3656c75e619b824aaea38f1373e31dad699d7a48
author Sanjay Patel <spatel@rotateright.com> 1504653193 +0000
committer Sanjay Patel <spatel@rotateright.com> 1504653193 +0000

[ValueTracking, InstCombine] canonicalize fcmp ord/uno with non-NAN ops to null constants

This is a preliminary step towards solving the remaining part of PR27145 - IR for isfinite():
https://bugs.llvm.org/show_bug.cgi?id=27145

In order to solve that one more generally, we need to add matching for and/or of fcmp ord/uno
with a constant operand.

But while looking at those patterns, I realized we were missing a canonicalization for nonzero
constants. Rather than limiting to just folds for constants, we're adding a general value
tracking method for this based on an existing DAG helper.

By transforming everything to 0.0, we can simplify the existing code in foldLogicOfFCmps()
and pick up missing vector folds.

Differential Revision: https://reviews.llvm.org/D37427


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312591 91177308-0d34-0410-b5e6-96231b3b80d8