Before patch: init nbits = 17, get 10000 samples, average cost: 16105 us After patch: init nbits = 17, get 10000 samples, average cost: 15221 us
Signed-off-by: Steven Liu <l...@chinaffmpeg.org> --- libavcodec/fft_template.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/libavcodec/fft_template.c b/libavcodec/fft_template.c index 762c014bc8..2b528be882 100644 --- a/libavcodec/fft_template.c +++ b/libavcodec/fft_template.c @@ -261,17 +261,21 @@ av_cold int ff_fft_init(FFTContext *s, int nbits, int inverse) if (s->fft_permutation == FF_FFT_PERM_AVX) { fft_perm_avx(s); } else { - for(i=0; i<n; i++) { - int k; - j = i; - if (s->fft_permutation == FF_FFT_PERM_SWAP_LSBS) - j = (j&~3) | ((j>>1)&1) | ((j<<1)&2); - k = -split_radix_permutation(i, n, s->inverse) & (n-1); - if (s->revtab) - s->revtab[k] = j; - if (s->revtab32) - s->revtab32[k] = j; - } +#define SPLIT_RADIX_PERMUTATION(num) do { \ + for(i=0; i<n; i++) {\ + int k;\ + j = i;\ + if (s->fft_permutation == FF_FFT_PERM_SWAP_LSBS)\ + j = (j&~3) | ((j>>1)&1) | ((j<<1)&2);\ + k = -split_radix_permutation(i, n, s->inverse) & (n-1);\ + s->revtab##num[k] = j;\ + }\ +} while(0); + if (s->revtab) + SPLIT_RADIX_PERMUTATION() + if (s->revtab32) + SPLIT_RADIX_PERMUTATION(32) +#undef SPLIT_RADIX_PERMUTATION } return 0; -- 2.15.2 (Apple Git-101.1) _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel