OT : Approximate / fast math libraries ?

Mike McCarty Mike.McCarty at sbcglobal.net
Wed Sep 5 02:49:46 UTC 2007


Bruno Wolff III wrote:
> On Tue, Sep 04, 2007 at 17:32:45 -0700,
>   Les <hlhowell at pacbell.net> wrote:
> 
>>	The same is true of Floating point operations vs integers.  When floats
>>had to be calculated by loops with an integer processor, they were
>>expensive and integers were faster.  Now with high speed floating point
>>units, simple float operations are quite fast if done in line.  Ditto
> 
> 
> On some models of crays the floating point units were faster than the
> integer units. I don't remember if that was because interger operations
> may not have been vectorizable or if there was some other reason for it.
> 

Some models of CRAYS had no fixed point instructions at all.
Today, the 486 and later machines in the Intel architecture
are FASTER at floating point than with integers.

The best way to get the speed this fellow is looking for is
to ensure that the fp hardware is actually being used.

Mike
-- 
p="p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);}
Oppose globalization and One World Governments like the UN.
This message made from 100% recycled bits.
You have found the bank of Larn.
I can explain it for you, but I can't understand it for you.
I speak only for myself, and I am unanimous in that!




More information about the fedora-list mailing list