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| author | Christophe Gisquet <christophe.gisquet@gmail.com> | 2013-04-09 21:57:09 +0000 |
|---|---|---|
| committer | Diego Biurrun <diego@biurrun.de> | 2013-05-03 18:23:30 +0200 |
| commit | 8394d9a676db1ffa1c8e4f6dd239e154d051ce03 (patch) | |
| tree | c020c193da5000aa97be45792e0d403e4775c152 | |
| parent | 5a97469a4fd12ef0327292ad6062f89a5e055a62 (diff) | |
| download | ffmpeg-8394d9a676db1ffa1c8e4f6dd239e154d051ce03.tar.gz | |
sbrdsp: Unroll sbr_autocorrelate_c
1410 cycles to 1148 on Arrandale/Win64
Signed-off-by: Diego Biurrun <diego@biurrun.de>
| -rw-r--r-- | libavcodec/sbrdsp.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/libavcodec/sbrdsp.c b/libavcodec/sbrdsp.c index 781ec83fe8..85b4ebefb4 100644 --- a/libavcodec/sbrdsp.c +++ b/libavcodec/sbrdsp.c @@ -122,9 +122,34 @@ static av_always_inline void autocorrelate(const float x[40][2], static void sbr_autocorrelate_c(const float x[40][2], float phi[3][2][2]) { +#if 0 + /* This code is slower because it multiplies memory accesses. + * It is left for educational purposes and because it may offer + * a better reference for writing arch-specific DSP functions. */ autocorrelate(x, phi, 0); autocorrelate(x, phi, 1); autocorrelate(x, phi, 2); +#else + float real_sum2 = x[0][0] * x[2][0] + x[0][1] * x[2][1]; + float imag_sum2 = x[0][0] * x[2][1] - x[0][1] * x[2][0]; + float real_sum1 = 0.0f, imag_sum1 = 0.0f, real_sum0 = 0.0f; + int i; + for (i = 1; i < 38; i++) { + real_sum0 += x[i][0] * x[i ][0] + x[i][1] * x[i ][1]; + real_sum1 += x[i][0] * x[i + 1][0] + x[i][1] * x[i + 1][1]; + imag_sum1 += x[i][0] * x[i + 1][1] - x[i][1] * x[i + 1][0]; + real_sum2 += x[i][0] * x[i + 2][0] + x[i][1] * x[i + 2][1]; + imag_sum2 += x[i][0] * x[i + 2][1] - x[i][1] * x[i + 2][0]; + } + phi[2 - 2][1][0] = real_sum2; + phi[2 - 2][1][1] = imag_sum2; + phi[2 ][1][0] = real_sum0 + x[ 0][0] * x[ 0][0] + x[ 0][1] * x[ 0][1]; + phi[1 ][0][0] = real_sum0 + x[38][0] * x[38][0] + x[38][1] * x[38][1]; + phi[2 - 1][1][0] = real_sum1 + x[ 0][0] * x[ 1][0] + x[ 0][1] * x[ 1][1]; + phi[2 - 1][1][1] = imag_sum1 + x[ 0][0] * x[ 1][1] - x[ 0][1] * x[ 1][0]; + phi[0 ][0][0] = real_sum1 + x[38][0] * x[39][0] + x[38][1] * x[39][1]; + phi[0 ][0][1] = imag_sum1 + x[38][0] * x[39][1] - x[38][1] * x[39][0]; +#endif } static void sbr_hf_gen_c(float (*X_high)[2], const float (*X_low)[2], |