Mail Archives: djgpp/1997/02/08/06:19:04
Marc Singer (elf AT netcom DOT com) wrote:
<snip>
: I have been working on an implementation of a DCT (discrete cosine
: transform) and have found the suprising results that the fixed point
: integer version is slower than the floating point version on both on a
: 486 and on a P5. I am not claiming that this will always be the case,
: but I was astonished to find that the fixed point version was twice as
: slow as the floating point implementation. I intend to look into this
: more and will post again when I have a conclusion.
:
I have the opposite experience, on a P90 a float inverse DCT increases the
run time by 10% over a fixed point inverse DCT. The inverse DCT is about
half of the computation, so the real increase is more like 20%.
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