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Re: speed of double-precision divide


On Sat, Jan 23, 2010 at 8:47 AM, Steve White <swhite@aip.de> wrote:
> gcc has this (gcc -std=c99 -O3 -msse2 -mfpmath=sse -lm -S dt.c)
> icc has this (icc -Wall -w2 -fast -c dt.c)

icc's -fast is equivalent to gcc's -ffast-math option which you did
not supply so you comparing apples to oranges.

Note supplying -ffast-math will have gcc to pull out the division out
of the loop which should speed up your program with some loss of
precision.

Thanks,
Andrew Pinski


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