[LLVMdev] Need Advice on AVX
dag at cray.com
Tue Dec 1 08:11:19 PST 2009
On Thursday 26 November 2009 14:25, Chris Lattner wrote:
> > Modeling subregisters isn't hard. Do you have some guidance as to when
> > one method is preferable? I am leaning toward using the modifier since
> > conceptually, a vector_extract of element zero on a v4i64 makes sense
> > with AVX (so it is "legal"). You just have to emit the register name as
> > "xmm" rather than "ymm." Why write an additional complicated pattern for
> > this case?
> Please don't use asmprinter modifiers. I'm trying to remove them as part
> of the MCization code. Please use the SUBREG machine instr and (subreg)
> tblgen node as appropriate.
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