[PATCH] D44548: [DAGCombiner] Expand combining of FP logical operations to sign-setting FP operations

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai added a comment.

In https://reviews.llvm.org/D44548#1258889, @spatel wrote:

> How about enabling the hook for PPC before adding to the generic DAG combine...
>  Right now, you'll get something horrible for normal fabs (and fneg?) without this patch, right?
>
>   	xscvdpspn 0, 1
>   	xxsldwi 0, 0, 0, 3
>   	mfvsrwz 3, 0
>   	rlwinm 3, 3, 0, 1, 31
>   	mtvsrd 0, 3
>   	xxsldwi 0, 0, 0, 1
>   	xscvspdpn 1, 0
>  
>


Yes. Although that is the worst case (since PPC `f32` isn't 32 bits in a register).
No doubt, the PPC-specific portion of this needs to go in and can certainly go in first. I can commit this as the PPC portion first (with the `fnabs` test missing). And then the generic part (adding the `fnabs` test).
The question is do I need to split this into two patches and post for review or can I just commit it as two separate patches (or maybe just commit the PPC-portion and post the generic portion for review)?


Repository:
  rL LLVM

https://reviews.llvm.org/D44548