[llvm-commits] [llvm] r77407 - in /llvm/trunk: include/llvm/IntrinsicsX86.td lib/Target/X86/X86ISelLowering.cpp lib/Target/X86/X86ISelLowering.h lib/Target/X86/X86InstrSSE.td test/CodeGen/X86/sse41.ll

[Chris Lattner]

On Jul 28, 2009, at 10:44 PM, Evan Cheng wrote:

>> Ok, that's what I feared.  This means that we need conditional flag
>> liveness stuff?  Is there a way to know (e.g. in regalloc, when doing
>> a spill) that only one flag is used?  Do we have flag subregs?
>
> Not yet.
>
> If we care about this, the solution is to lower ptestz and ptestc,
> ptestnzc to different x86isd nodes.

Yes, that would work for commuting at isel time to match the load.   
This wouldn't work for commuting to fold a reload.

-Chris