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Re: Vector subregs


On Fri, Dec 14, 2001 at 04:59:39PM -0200, Alexandre Oliva wrote:
> On Dec 14, 2001, Dale Johannesen <dalej@apple.com> wrote:
> 
> > Subreg's of vectors don't have a register implementation on any
> > hardware AFAIK, so there is no reason to support them.
> 
> Hmm...  The SH4 can use 4 FP registers as a V4SF unit for some
> operations, as well as 4 of these sets as a 4x4 SF matrix.  I suppose
> it would be reasonable to be able to use subregs to refer to
> individual registers that compose such vectors and matrices, wouldn't
> it?

Similarly on SPARC, e.g. for V2SI register you can access the 32-bit subregs
individually.

	Jakub


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