mirror/kissfft
1
0
Fork 0
mirror of https://github.com/mborgerding/kissfft.git synced 2025-06-04 01:28:23 -04:00
Code Issues Packages Projects Releases Wiki Activity

reduced calling parameters

Browse Source 
negligible performane impact
This commit is contained in:
Mark Borgerding 2003-10-11 23:07:16 +00:00
parent 0d44569b3b
commit 0d6d61cfce
1 changed files with 8 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
kiss_fft.c
View File

@ -27,7 +27,6 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* }kiss_fft_cpx; * }kiss_fft_cpx;
*/ */
typedef struct { typedef struct {
int nfft; int nfft;
int inverse; int inverse;
@ -65,38 +64,31 @@ kiss_fft_cpx cexp(double phase)
return x; return x;
} }
static kiss_fft_cpx cmul(kiss_fft_cpx a,kiss_fft_cpx b)
{
kiss_fft_cpx c;
C_MUL(c,a,b);
return c;
}
// the heart of the fft // the heart of the fft
static static
void fft_work( void fft_work(
kiss_fft_cpx * Fout, kiss_fft_cpx * Fout,
const kiss_fft_cpx * f, const kiss_fft_cpx * f,
int fstride, int fstride,
int n, int * factors,
int Norig, const kiss_fft_state * st
int inverse,
kiss_fft_cpx * scratch,
kiss_fft_cpx * twiddles,
int * factors
) )
{ {
int m,p=0,q,q1,u,k; int m,p=0,q,q1,u,k;
kiss_fft_cpx t; kiss_fft_cpx t;
kiss_fft_cpx * scratch = st->scratch;
kiss_fft_cpx * twiddles = st->twiddles;
int Norig = st->nfft;
p=*factors++; p=*factors++;
m=*factors++;//m = n/p; m=*factors++;//m = n/p;
for (q=0;q<p;++q) { for (q=0;q<p;++q) {
// TODO f+= fstride; instead of offset below
if (m==1) if (m==1)
*(Fout + m*q) = *(f+q*fstride); *(Fout + m*q) = *(f+q*fstride);
else else
fft_work( Fout + m*q, f+q*fstride, fstride*p, m,Norig,inverse, scratch ,twiddles,factors); fft_work( Fout + m*q, f+q*fstride, fstride*p,factors,st);
} }
for ( u=0; u<m; ++u ) { for ( u=0; u<m; ++u ) {
@ -159,12 +151,6 @@ void * kiss_fft_alloc(int nfft,int inverse_fft)
st->scratch = (kiss_fft_cpx*)(st->tmpbuf + nfft); st->scratch = (kiss_fft_cpx*)(st->tmpbuf + nfft);
st->factors = (int*)(st->scratch + nfft); // just after tmpbuf st->factors = (int*)(st->scratch + nfft); // just after tmpbuf
/*
st->twiddles = (kiss_fft_cpx*)malloc( sizeof(kiss_fft_cpx)*nfft );
st->tmpbuf = (kiss_fft_cpx*)malloc( sizeof(kiss_fft_cpx)*nfft );
st->scratch = (kiss_fft_cpx*)malloc( sizeof(kiss_fft_cpx)*nfft );
st->factors = (int*)malloc( sizeof(int)*nfft );
*/
for (i=0;i<nfft;++i) { for (i=0;i<nfft;++i) {
const double pi=3.14159265358979323846264338327; const double pi=3.14159265358979323846264338327;
@ -200,5 +186,5 @@ void kiss_fft(const void * cfg,kiss_fft_cpx *f)
n = st->nfft; n = st->nfft;
memcpy(st->tmpbuf,f,sizeof(kiss_fft_cpx)*n); memcpy(st->tmpbuf,f,sizeof(kiss_fft_cpx)*n);
fft_work( f, st->tmpbuf, 1, n,n, st->inverse, st->scratch ,st->twiddles,st->factors); fft_work( f, st->tmpbuf, 1, st->factors,st );
} }