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FFmpeg/libavcodec/ppc/fft_altivec.c
Romain Dolbeau e45a2872fa 1) remove TBL support in PPC performance. It's much more useful to use the
PMCs, and with Apple's CHUD it's fairly easy too. No reason to keep useless
    code around
2) make the PPC perf stuff a configure option
3) make put_pixels16_altivec a bit faster by unrolling the loop by 4
patch by (Romain Dolbeau <dolbeau at irisa dot fr>)

Originally committed as revision 2022 to svn://svn.ffmpeg.org/ffmpeg/trunk
2003-07-09 20:18:13 +00:00

248 lines
6.7 KiB
C

/*
* FFT/IFFT transforms
* AltiVec-enabled
* Copyright (c) 2003 Romain Dolbeau <romain@dolbeau.org>
* Based on code Copyright (c) 2002 Fabrice Bellard.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "../dsputil.h"
#include "gcc_fixes.h"
#include "dsputil_altivec.h"
/*
those three macros are from libavcodec/fft.c
and are required for the reference C code
*/
/* butter fly op */
#define BF(pre, pim, qre, qim, pre1, pim1, qre1, qim1) \
{\
FFTSample ax, ay, bx, by;\
bx=pre1;\
by=pim1;\
ax=qre1;\
ay=qim1;\
pre = (bx + ax);\
pim = (by + ay);\
qre = (bx - ax);\
qim = (by - ay);\
}
#define MUL16(a,b) ((a) * (b))
#define CMUL(pre, pim, are, aim, bre, bim) \
{\
pre = (MUL16(are, bre) - MUL16(aim, bim));\
pim = (MUL16(are, bim) + MUL16(bre, aim));\
}
/**
* Do a complex FFT with the parameters defined in 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 pair of float
* The code is exactly the same as the SSE version, except
* that successive MUL + ADD/SUB have been merged into
* fused multiply-add ('vec_madd' in altivec)
*/
void fft_calc_altivec(FFTContext *s, FFTComplex *z)
{
POWERPC_PERF_DECLARE(altivec_fft_num, s->nbits >= 6);
#ifdef ALTIVEC_USE_REFERENCE_C_CODE
int ln = s->nbits;
int j, np, np2;
int nblocks, nloops;
register FFTComplex *p, *q;
FFTComplex *exptab = s->exptab;
int l;
FFTSample tmp_re, tmp_im;
POWERPC_PERF_START_COUNT(altivec_fft_num, s->nbits >= 6);
np = 1 << ln;
/* pass 0 */
p=&z[0];
j=(np >> 1);
do {
BF(p[0].re, p[0].im, p[1].re, p[1].im,
p[0].re, p[0].im, p[1].re, p[1].im);
p+=2;
} while (--j != 0);
/* pass 1 */
p=&z[0];
j=np >> 2;
if (s->inverse) {
do {
BF(p[0].re, p[0].im, p[2].re, p[2].im,
p[0].re, p[0].im, p[2].re, p[2].im);
BF(p[1].re, p[1].im, p[3].re, p[3].im,
p[1].re, p[1].im, -p[3].im, p[3].re);
p+=4;
} while (--j != 0);
} else {
do {
BF(p[0].re, p[0].im, p[2].re, p[2].im,
p[0].re, p[0].im, p[2].re, p[2].im);
BF(p[1].re, p[1].im, p[3].re, p[3].im,
p[1].re, p[1].im, p[3].im, -p[3].re);
p+=4;
} while (--j != 0);
}
/* pass 2 .. ln-1 */
nblocks = np >> 3;
nloops = 1 << 2;
np2 = np >> 1;
do {
p = z;
q = z + nloops;
for (j = 0; j < nblocks; ++j) {
BF(p->re, p->im, q->re, q->im,
p->re, p->im, q->re, q->im);
p++;
q++;
for(l = nblocks; l < np2; l += nblocks) {
CMUL(tmp_re, tmp_im, exptab[l].re, exptab[l].im, q->re, q->im);
BF(p->re, p->im, q->re, q->im,
p->re, p->im, tmp_re, tmp_im);
p++;
q++;
}
p += nloops;
q += nloops;
}
nblocks = nblocks >> 1;
nloops = nloops << 1;
} while (nblocks != 0);
POWERPC_PERF_STOP_COUNT(altivec_fft_num, s->nbits >= 6);
#else /* ALTIVEC_USE_REFERENCE_C_CODE */
#ifdef CONFIG_DARWIN
register const vector float vczero = (const vector float)(0.);
#else
register const vector float vczero = (const vector float){0.,0.,0.,0.};
#endif
int ln = s->nbits;
int j, np, np2;
int nblocks, nloops;
register FFTComplex *p, *q;
FFTComplex *cptr, *cptr1;
int k;
POWERPC_PERF_START_COUNT(altivec_fft_num, s->nbits >= 6);
np = 1 << ln;
{
vector float *r, a, b, a1, c1, c2;
r = (vector float *)&z[0];
c1 = vcii(p,p,n,n);
if (s->inverse)
{
c2 = vcii(p,p,n,p);
}
else
{
c2 = vcii(p,p,p,n);
}
j = (np >> 2);
do {
a = vec_ld(0, r);
a1 = vec_ld(sizeof(vector float), r);
b = vec_perm(a,a,vcprmle(1,0,3,2));
a = vec_madd(a,c1,b);
/* do the pass 0 butterfly */
b = vec_perm(a1,a1,vcprmle(1,0,3,2));
b = vec_madd(a1,c1,b);
/* do the pass 0 butterfly */
/* multiply third by -i */
b = vec_perm(b,b,vcprmle(2,3,1,0));
/* do the pass 1 butterfly */
vec_st(vec_madd(b,c2,a), 0, r);
vec_st(vec_nmsub(b,c2,a), sizeof(vector float), r);
r += 2;
} while (--j != 0);
}
/* pass 2 .. ln-1 */
nblocks = np >> 3;
nloops = 1 << 2;
np2 = np >> 1;
cptr1 = s->exptab1;
do {
p = z;
q = z + nloops;
j = nblocks;
do {
cptr = cptr1;
k = nloops >> 1;
do {
vector float a,b,c,t1;
a = vec_ld(0, (float*)p);
b = vec_ld(0, (float*)q);
/* complex mul */
c = vec_ld(0, (float*)cptr);
/* cre*re cim*re */
t1 = vec_madd(c, vec_perm(b,b,vcprmle(2,2,0,0)),vczero);
c = vec_ld(sizeof(vector float), (float*)cptr);
/* -cim*im cre*im */
b = vec_madd(c, vec_perm(b,b,vcprmle(3,3,1,1)),t1);
/* butterfly */
vec_st(vec_add(a,b), 0, (float*)p);
vec_st(vec_sub(a,b), 0, (float*)q);
p += 2;
q += 2;
cptr += 4;
} while (--k);
p += nloops;
q += nloops;
} while (--j);
cptr1 += nloops * 2;
nblocks = nblocks >> 1;
nloops = nloops << 1;
} while (nblocks != 0);
POWERPC_PERF_STOP_COUNT(altivec_fft_num, s->nbits >= 6);
#endif /* ALTIVEC_USE_REFERENCE_C_CODE */
}