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Re: more tidying of x86 feature tests


On Wed, Mar 07, 2007 at 08:13:21AM -0800, H. J. Lu wrote:
> > BTW: Does CORE2 also prefer sahf?
> 
> Compared with what?

Bit tests vs ax.  E.g.

        fnstsw  %ax
        testb   $1, %ah
        jne     .L5
vs
        fnstsw  %ax
        sahf
        jb      .L5

Though I guess it really ought not make any difference
whatsoever, because 64-bit should always use fcomi.


r~


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