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Re: Calculating cosinus/sinus


On 5/11/2013 5:42 AM, jacob navia wrote:

1) The fsin instruction is ONE instruction! The sin routine is (at
least) thousand instructions!
     Even if the fsin instruction itself is "slow" it should be thousand
times faster than the
     complicated routine gcc calls.
2) The FPU is at 64 bits mantissa using gcc, i.e. fsin will calculate
with 64 bits mantissa and
     NOT only 53 as SSE2. The fsin instruction is more precise!

You are making conclusions based on naive assumptions here.

I think that gcc has a problem here. I am pointing you to this problem,
but please keep in mind
I am no newbee...

Sure, but that does not mean you are familiar with the intracacies
of accurate computation of transcendental functions!

jacob



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