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245 lines
6.6 KiB
245 lines
6.6 KiB
/* |
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* FFT/IFFT transforms |
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* AltiVec-enabled |
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* Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org> |
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* Based on code Copyright (c) 2002 Fabrice Bellard. |
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* |
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* This library is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2 of the License, or (at your option) any later version. |
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* |
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* This library is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with this library; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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#include "../dsputil.h" |
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#include "dsputil_altivec.h" |
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/* |
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those three macros are from libavcodec/fft.c |
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and are required for the reference C code |
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*/ |
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/* butter fly op */ |
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#define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \ |
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{\ |
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FFTSample ax, ay, bx, by;\ |
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bx=pre1;\ |
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by=pim1;\ |
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ax=qre1;\ |
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ay=qim1;\ |
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pre = (bx + ax);\ |
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pim = (by + ay);\ |
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qre = (bx - ax);\ |
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qim = (by - ay);\ |
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} |
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#define MUL16(a,b) ((a) * (b)) |
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#define CMUL(pre, pim, are, aim, bre, bim) \ |
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{\ |
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pre = (MUL16(are, bre) - MUL16(aim, bim));\ |
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pim = (MUL16(are, bim) + MUL16(bre, aim));\ |
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} |
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/** |
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* Do a complex FFT with the parameters defined in fft_init(). The |
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* input data must be permuted before with s->revtab table. No |
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* 1.0/sqrt(n) normalization is done. |
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* AltiVec-enabled |
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* This code assumes that the 'z' pointer is 16 bytes-aligned |
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* It also assumes all FFTComplex are 8 bytes-aligned pair of float |
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* The code is exactly the same as the SSE version, except |
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* that successive MUL + ADD/SUB have been merged into |
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* fused multiply-add ('vec_madd' in altivec) |
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*/ |
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void fft_calc_altivec(FFTContext *s, FFTComplex *z) |
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{ |
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POWERPC_TBL_DECLARE(altivec_fft_num, s->nbits >= 6); |
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#ifdef ALTIVEC_USE_REFERENCE_C_CODE |
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int ln = s->nbits; |
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int j, np, np2; |
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int nblocks, nloops; |
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register FFTComplex *p, *q; |
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FFTComplex *exptab = s->exptab; |
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int l; |
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FFTSample tmp_re, tmp_im; |
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POWERPC_TBL_START_COUNT(altivec_fft_num, s->nbits >= 6); |
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np = 1 << ln; |
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/* pass 0 */ |
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p=&z[0]; |
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j=(np >> 1); |
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do { |
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BF(p[0].re, p[0].im, p[1].re, p[1].im, |
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p[0].re, p[0].im, p[1].re, p[1].im); |
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p+=2; |
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} while (--j != 0); |
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/* pass 1 */ |
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p=&z[0]; |
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j=np >> 2; |
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if (s->inverse) { |
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do { |
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BF(p[0].re, p[0].im, p[2].re, p[2].im, |
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p[0].re, p[0].im, p[2].re, p[2].im); |
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BF(p[1].re, p[1].im, p[3].re, p[3].im, |
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p[1].re, p[1].im, -p[3].im, p[3].re); |
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p+=4; |
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} while (--j != 0); |
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} else { |
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do { |
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BF(p[0].re, p[0].im, p[2].re, p[2].im, |
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p[0].re, p[0].im, p[2].re, p[2].im); |
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BF(p[1].re, p[1].im, p[3].re, p[3].im, |
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p[1].re, p[1].im, p[3].im, -p[3].re); |
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p+=4; |
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} while (--j != 0); |
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} |
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/* pass 2 .. ln-1 */ |
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nblocks = np >> 3; |
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nloops = 1 << 2; |
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np2 = np >> 1; |
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do { |
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p = z; |
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q = z + nloops; |
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for (j = 0; j < nblocks; ++j) { |
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BF(p->re, p->im, q->re, q->im, |
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p->re, p->im, q->re, q->im); |
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p++; |
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q++; |
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for(l = nblocks; l < np2; l += nblocks) { |
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CMUL(tmp_re, tmp_im, exptab[l].re, exptab[l].im, q->re, q->im); |
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BF(p->re, p->im, q->re, q->im, |
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p->re, p->im, tmp_re, tmp_im); |
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p++; |
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q++; |
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} |
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p += nloops; |
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q += nloops; |
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} |
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nblocks = nblocks >> 1; |
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nloops = nloops << 1; |
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} while (nblocks != 0); |
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POWERPC_TBL_STOP_COUNT(altivec_fft_num, s->nbits >= 6); |
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#else /* ALTIVEC_USE_REFERENCE_C_CODE */ |
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#ifdef CONFIG_DARWIN |
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register const vector float vczero = (const vector float)(0.); |
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#else |
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register const vector float vczero = (const vector float){0.,0.,0.,0.}; |
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#endif |
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int ln = s->nbits; |
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int j, np, np2; |
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int nblocks, nloops; |
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register FFTComplex *p, *q; |
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FFTComplex *cptr, *cptr1; |
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int k; |
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POWERPC_TBL_START_COUNT(altivec_fft_num, s->nbits >= 6); |
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np = 1 << ln; |
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{ |
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vector float *r, a, b, a1, c1, c2; |
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r = (vector float *)&z[0]; |
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c1 = vcii(p,p,n,n); |
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if (s->inverse) |
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{ |
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c2 = vcii(p,p,n,p); |
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} |
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else |
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{ |
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c2 = vcii(p,p,p,n); |
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} |
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j = (np >> 2); |
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do { |
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a = vec_ld(0, r); |
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a1 = vec_ld(sizeof(vector float), r); |
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b = vec_perm(a,a,vcprmle(1,0,3,2)); |
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a = vec_madd(a,c1,b); |
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/* do the pass 0 butterfly */ |
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b = vec_perm(a1,a1,vcprmle(1,0,3,2)); |
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b = vec_madd(a1,c1,b); |
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/* do the pass 0 butterfly */ |
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/* multiply third by -i */ |
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b = vec_perm(b,b,vcprmle(2,3,1,0)); |
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/* do the pass 1 butterfly */ |
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vec_st(vec_madd(b,c2,a), 0, r); |
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vec_st(vec_nmsub(b,c2,a), sizeof(vector float), r); |
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r += 2; |
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} while (--j != 0); |
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} |
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/* pass 2 .. ln-1 */ |
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nblocks = np >> 3; |
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nloops = 1 << 2; |
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np2 = np >> 1; |
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cptr1 = s->exptab1; |
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do { |
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p = z; |
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q = z + nloops; |
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j = nblocks; |
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do { |
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cptr = cptr1; |
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k = nloops >> 1; |
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do { |
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vector float a,b,c,t1; |
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a = vec_ld(0, (float*)p); |
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b = vec_ld(0, (float*)q); |
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/* complex mul */ |
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c = vec_ld(0, (float*)cptr); |
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/* cre*re cim*re */ |
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t1 = vec_madd(c, vec_perm(b,b,vcprmle(2,2,0,0)),vczero); |
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c = vec_ld(sizeof(vector float), (float*)cptr); |
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/* -cim*im cre*im */ |
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b = vec_madd(c, vec_perm(b,b,vcprmle(3,3,1,1)),t1); |
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/* butterfly */ |
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vec_st(vec_add(a,b), 0, (float*)p); |
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vec_st(vec_sub(a,b), 0, (float*)q); |
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p += 2; |
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q += 2; |
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cptr += 4; |
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} while (--k); |
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p += nloops; |
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q += nloops; |
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} while (--j); |
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cptr1 += nloops * 2; |
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nblocks = nblocks >> 1; |
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nloops = nloops << 1; |
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} while (nblocks != 0); |
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POWERPC_TBL_STOP_COUNT(altivec_fft_num, s->nbits >= 6); |
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#endif /* ALTIVEC_USE_REFERENCE_C_CODE */ |
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}
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