mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
133 lines
3.9 KiB
133 lines
3.9 KiB
/* |
|
* 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 "dsputil_altivec.h" |
|
|
|
/** |
|
* 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) |
|
{ |
|
register const vector float vczero = (vector float)( 0., 0., 0., 0.); |
|
|
|
int ln = s->nbits; |
|
int j, np, np2; |
|
int nblocks, nloops; |
|
register FFTComplex *p, *q; |
|
FFTComplex *cptr, *cptr1; |
|
int k; |
|
|
|
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); |
|
} |
|
|
|
|