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minor doc changes

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Mark Borgerding 2004-04-04 22:02:02 +00:00
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@ -7,6 +7,9 @@ Speed:
-ffast-math -ffast-math
-fomit-frame-pointer -fomit-frame-pointer
* If the input data has no imaginary component, use the kiss_fftr code under tools/.
Real ffts are roughly twice as fast as complex.
Reducing code size: Reducing code size:
* remove some of the butterflies. There are currently butterflies optimized for radices * remove some of the butterflies. There are currently butterflies optimized for radices
2,3,4,5. It is worth mentioning that you can still use FFT sizes that contain 2,3,4,5. It is worth mentioning that you can still use FFT sizes that contain
@ -14,3 +17,7 @@ Reducing code size:
whether to keep radix 2 or 4. If you do some work in this area, let me whether to keep radix 2 or 4. If you do some work in this area, let me
know what you find. know what you find.
* For platforms where ROM/code space is more plentiful than RAM,
consider creating a hardcoded kiss_fft_state. In other words, decide which
FFT size(s) you want and make a structure with the correct factors and twiddles.