[PATCH] D11592: [mips][FastISel] Apply only zero-extension to constants prior to their materialization.

[Daniel Sanders]

dsanders accepted this revision.
dsanders added a comment.
This revision is now accepted and ready to land.

LGTM. I agree that the real issue is that the analysis of known bits is getting the excess bits wrong and we ought to fix that but this patch at least fixes the known issues in Mips's Fast ISel. We can follow up on the known-bits analysis afterwards.

> More specifically, ComputePHILiveOutRegInfo() zero-extends (or

>  truncates to the bitwidth of destination-type) ...


These aren't quite the same thing. Is it assuming values are zero extended in their container or is considering the excess bits to be undefined? From your later comments I'm sure it's the former.

> AzzertZero


Nit: Typo


http://reviews.llvm.org/D11592