[LLVMdev] Need Advice on AVX

Anton Korobeynikov
Tue, 24 Nov 2009 20:12:20 -0000

Hello, David

> How does ${dst:subreg32} work?
This is just modifier provided to asmprinting code. Here, it seems, 16
bit register is passed to asmprinter, but it sees modifier and grabs
32-bit superreg.

> Can one do the same for sources?
Yes, this is just modifier for printing, nothing more...

> Is it preferable to use the source modifier or write an EXTRACT_SUBREG
> pattern explicitly?
It depends what you're want to do. But I guess you need to model
subreg access properly...

--
With best regards, Anton Korobeynikov
Faculty of Mathematics and Mechanics, Saint Petersburg State University