29 Sep
2007
29 Sep
'07
8:09 p.m.
Jens M Andreasen wrote:
Although you are approximately right in many parts of
this discussion,
you are wrong on the cost of the CPU flags to round twards zero. The
cost is nil.
My memory of this is that changing the FPU flags causes a pipeline flush.
If the happens inside an inner loop, this has a **huge** performance
penalty.
Unlike other forms of Voodoo, we can neasure this.
Have you?
Erik
--
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Erik de Castro Lopo
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Orcad Express 9: "Its a nice demo but I wouldn't want to use it
on a day-to-day basis" -- me