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sbrdsp: unroll sbr_autocorrelate_c

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1410 cycles to 1148 on Arrandale/Win64.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Christophe Gisquet 2013-04-06 10:52:12 +00:00 committed by Michael Niedermayer
parent ff50b08304
commit f4ac80227b
1 changed files with 25 additions and 0 deletions
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25
libavcodec/sbrdsp.c
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@ -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 as eucational purpose 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.f, imag_sum1 = 0.f, 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],