denormals (was: Re: [PD] Lost at compilig cyclone ;-(((()

Tim Blechmann TimBlechmann at gmx.net
Sat Jun 26 20:37:22 CEST 2004


hi all,

pd's handling of denormals could definitely be inproved ...

the question is, if a branch free algorithm improves the performance...
the quantization relies on two floating point performances, if the
number is a denormal, it will cause one denormal operation. the
PD_BADFLOAT macro does no floating point operation at all ...

another branch free possibility would be to do something like:

f*= !PD_BADFLOAT(f);

which would be branch free. the question is, it that would cause a
denormal operation, concerning jan depner, it depends on the compiler,
but pd is supposed to built on various compilers (gcc, icc, msvc ...)

it would probably be neccessary to do a few benchmarks in order to
figure out, what's giving the best performance ... the most efficient
solution would probably be to rewrite the specific functions using sse
instructions if available, on the specific platform... 

cheers ... tim

-- 
mailto:TimBlechmann at gmx.de    ICQ: 96771783

After one look at this planet any visitor from outer space 
would say "I want to see the manager."
				      William S. Burroughs




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