We already do the following combines:
(bitcast int (and (bitcast fp X to int), 0x7fff...) to fp) -> fabs X
(bitcast int (xor (bitcast fp X to int), 0x8000...) to fp) -> fneg X
When the target has "bit preserving fp logic". This patch just extends it
to also combine:
(bitcast int (or (bitcast fp X to int), 0x8000...) to fp) -> fneg (fabs X)
As some targets have fnabs and even those that don't can efficiently lower
both the fabs and the fneg.
Differential revision: https://reviews.llvm.org/D44548
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344093 91177308-0d34-0410-b5e6-96231b3b80d8
This just adds the test case so that the different code gen is clearly visible
when the DAG Combine lands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344091 91177308-0d34-0410-b5e6-96231b3b80d8
This is the PPC-specific non-controversial part of
https://reviews.llvm.org/D44548 that simply enables this combine for PPC
since PPC has these instructions.
This commit will allow the target-independent portion to be truly target
independent.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@344077 91177308-0d34-0410-b5e6-96231b3b80d8
