/* * FFT/IFFT transforms * AltiVec-enabled * Copyright (c) 2009 Loren Merritt * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "config.h"#include "libavutil/cpu.h"#include "libavutil/ppc/cpu.h"#include "libavutil/ppc/types_altivec.h"#include "libavutil/ppc/util_altivec.h"#include "libavcodec/fft.h" /** * Do a complex FFT with the parameters defined in ff_fft_init(). * The input data must be permuted before with s->revtab table. * No 1.0 / sqrt(n) normalization is done. * AltiVec-enabled: * This code assumes that the 'z' pointer is 16 bytes-aligned. * It also assumes all FFTComplex are 8 bytes-aligned pairs of floats. */ #if HAVE_VSX#include "fft_vsx.h"#elsevoid ff_fft_calc_altivec(FFTContext *s, FFTComplex *z);void ff_fft_calc_interleave_altivec(FFTContext *s, FFTComplex *z);#endif #if HAVE_GNU_AS && HAVE_ALTIVECstatic void imdct_half_altivec(FFTContext *s, FFTSample *output, const FFTSample *input){    int j, k;    int n = 1 << s->mdct_bits;    int n4 = n >> 2;    int n8 = n >> 3;    int n32 = n >> 5;    const uint16_t *revtabj = s->revtab;    const uint16_t *revtabk = s->revtab+n4;    const vec_f *tcos = (const vec_f*)(s->tcos+n8);    const vec_f *tsin = (const vec_f*)(s->tsin+n8);    const vec_f *pin = (const vec_f*)(input+n4);    vec_f *pout = (vec_f*)(output+n4);     /* pre rotation */    k = n32-1;    do {        vec_f cos,sin,cos0,sin0,cos1,sin1,re,im,r0,i0,r1,i1,a,b,c,d;#define CMULA(p,o0,o1,o2,o3)\        a = pin[ k*2+p];                       /* { z[k].re,    z[k].im,    z[k+1].re,  z[k+1].im  } */\        b = pin[-k*2-p-1];                     /* { z[-k-2].re, z[-k-2].im, z[-k-1].re, z[-k-1].im } */\        re = vec_perm(a, b, vcprm(0,2,s0,s2)); /* { z[k].re,    z[k+1].re,  z[-k-2].re, z[-k-1].re } */\        im = vec_perm(a, b, vcprm(s3,s1,3,1)); /* { z[-k-1].im, z[-k-2].im, z[k+1].im,  z[k].im    } */\        cos = vec_perm(cos0, cos1, vcprm(o0,o1,s##o2,s##o3)); /* { cos[k], cos[k+1], cos[-k-2], cos[-k-1] } */\        sin = vec_perm(sin0, sin1, vcprm(o0,o1,s##o2,s##o3));\        r##p = im*cos - re*sin;\        i##p = re*cos + im*sin;#define STORE2(v,dst)\        j = dst;\        vec_ste(v, 0, output+j*2);\        vec_ste(v, 4, output+j*2);#define STORE8(p)\        a = vec_perm(r##p, i##p, vcprm(0,s0,0,s0));\        b = vec_perm(r##p, i##p, vcprm(1,s1,1,s1));\        c = vec_perm(r##p, i##p, vcprm(2,s2,2,s2));\        d = vec_perm(r##p, i##p, vcprm(3,s3,3,s3));\        STORE2(a, revtabk[ p*2-4]);\        STORE2(b, revtabk[ p*2-3]);\        STORE2(c, revtabj[-p*2+2]);\        STORE2(d, revtabj[-p*2+3]);         cos0 = tcos[k];        sin0 = tsin[k];        cos1 = tcos[-k-1];        sin1 = tsin[-k-1];        CMULA(0, 0,1,2,3);        CMULA(1, 2,3,0,1);        STORE8(0);        STORE8(1);        revtabj += 4;        revtabk -= 4;        k--;    } while(k >= 0); #if HAVE_VSX    ff_fft_calc_vsx(s, (FFTComplex*)output);#else    ff_fft_calc_altivec(s, (FFTComplex*)output);#endif     /* post rotation + reordering */    j = -n32;    k = n32-1;    do {        vec_f cos,sin,re,im,a,b,c,d;#define CMULB(d0,d1,o)\        re = pout[o*2];\        im = pout[o*2+1];\        cos = tcos[o];\        sin = tsin[o];\        d0 = im*sin - re*cos;\        d1 = re*sin + im*cos;         CMULB(a,b,j);        CMULB(c,d,k);        pout[2*j]   = vec_perm(a, d, vcprm(0,s3,1,s2));        pout[2*j+1] = vec_perm(a, d, vcprm(2,s1,3,s0));        pout[2*k]   = vec_perm(c, b, vcprm(0,s3,1,s2));        pout[2*k+1] = vec_perm(c, b, vcprm(2,s1,3,s0));        j++;        k--;    } while(k >= 0);} static void imdct_calc_altivec(FFTContext *s, FFTSample *output, const FFTSample *input){    int k;    int n = 1 << s->mdct_bits;    int n4 = n >> 2;    int n16 = n >> 4;    vec_u32 sign = {1U<<31,1U<<31,1U<<31,1U<<31};    vec_u32 *p0 = (vec_u32*)(output+n4);    vec_u32 *p1 = (vec_u32*)(output+n4*3);     imdct_half_altivec(s, output + n4, input);     for (k = 0; k < n16; k++) {        vec_u32 a = p0[k] ^ sign;        vec_u32 b = p1[-k-1];        p0[-k-1] = vec_perm(a, a, vcprm(3,2,1,0));        p1[k]    = vec_perm(b, b, vcprm(3,2,1,0));    }}#endif /* HAVE_GNU_AS && HAVE_ALTIVEC && HAVE_BIGENDIAN */ av_cold void ff_fft_init_ppc(FFTContext *s){#if HAVE_GNU_AS && HAVE_ALTIVEC    if (!PPC_ALTIVEC(av_get_cpu_flags()))        return; #if HAVE_VSX    s->fft_calc = ff_fft_calc_interleave_vsx;#else    s->fft_calc   = ff_fft_calc_interleave_altivec;#endif    if (s->mdct_bits >= 5) {        s->imdct_calc = imdct_calc_altivec;        s->imdct_half = imdct_half_altivec;    }#endif /* HAVE_GNU_AS && HAVE_ALTIVEC && HAVE_BIGENDIAN */}