Using mmx instructions.

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Frans Morsch

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Feb 3, 2000, 3:00:00 AM2/3/00
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Hi,

I am doing some 64 bit programming using mmx registers.

The problem is that none of the mmx instructions set
the flags. So how do you know for example if a mmx
register is zero. The best that I was able to come up
with is:
movd eax,mm0 ;Test if mm0 is null.
pslrq mm0,32 ;shift rigth
movd ebx,mm0
or eax,ebx
je .....

There must be a better (faster) way to do this, what
about using floating point instructions. I know that
mmx and fp aren't supposed to be mixed, but...

Hints, tips anyone ?


fmo...@xs4all.nl
Frans Morsch


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