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re-added radix 3 butterfly

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This commit is contained in:
Mark Borgerding 2003-10-30 02:02:29 +00:00
parent ca4c74e07c
commit d4f87befda
4 changed files with 81 additions and 25 deletions
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60
kiss_fft.c
View File

@ -59,6 +59,8 @@ typedef struct {
# define C_FIXDIV(c,div) /* NOOP */ # define C_FIXDIV(c,div) /* NOOP */
#endif #endif
#define C_ADD( res, a,b)\
do { (res).r=(a).r+(b).r; (res).i=(a).i+(b).i; }while(0)
#define C_SUB( res, a,b)\ #define C_SUB( res, a,b)\
do { (res).r=(a).r-(b).r; (res).i=(a).i-(b).i; }while(0) do { (res).r=(a).r-(b).r; (res).i=(a).i-(b).i; }while(0)
#define C_ADDTO( res , a)\ #define C_ADDTO( res , a)\
@ -162,6 +164,59 @@ void bfly4(
}while(--m); }while(--m);
} }
void bfly3(
kiss_fft_cpx * Fout,
int fstride,
const kiss_fft_state * st,
int m
)
{
kiss_fft_cpx *Fout0,*Fout1,*Fout2;
kiss_fft_cpx *tw1,*tw2;
kiss_fft_cpx * scratch = st->scratch;
kiss_fft_cpx * twiddles = st->twiddles;
kiss_fft_cpx epi3;
epi3 = twiddles[fstride*m];
Fout0=Fout;
Fout1=Fout0+m;
Fout2=Fout0+2*m;
tw1=tw2=twiddles;
do{
C_FIXDIV(*Fout,3); C_FIXDIV(*Fout1,3); C_FIXDIV(*Fout2,3);
scratch[0] = *Fout0;
C_MUL(scratch[1],*Fout1 , *tw1);
C_MUL(scratch[2],*Fout2 , *tw2);
tw1 += fstride;
tw2 += fstride*2;
C_ADD(scratch[4],scratch[1],scratch[2]);
C_ADD(*Fout0,scratch[0],scratch[4]);
scratch[4].r /= -2;
scratch[4].i /= -2;
C_SUB(scratch[5],scratch[1],scratch[2]);
scratch[5].r *= epi3.i;
scratch[5].i *= epi3.i;
scratch[3].r = scratch[4].r - scratch[5].i ;
scratch[3].i = scratch[4].i + scratch[5].r ;
C_ADD( *Fout1, scratch[0] , scratch[3] );
scratch[3].r = scratch[4].r + scratch[5].i;
scratch[3].i = scratch[4].i - scratch[5].r;
C_ADD( *Fout2, scratch[0] , scratch[3] );
++Fout0;++Fout1;++Fout2;
}while(--m);
}
/* perform the butterfly for one stage of a mixed radix FFT */ /* perform the butterfly for one stage of a mixed radix FFT */
void bfly_generic( void bfly_generic(
kiss_fft_cpx * Fout, kiss_fft_cpx * Fout,
@ -221,8 +276,11 @@ void fft_work(
} }
switch (p) { switch (p) {
case 4: bfly4(Fout,fstride,st,m); break;
case 2: bfly2(Fout,fstride,st,m); break; case 2: bfly2(Fout,fstride,st,m); break;
#if 1
case 3: bfly3(Fout,fstride,st,m); break;
#endif
case 4: bfly4(Fout,fstride,st,m); break;
default: bfly_generic(Fout,fstride,st,m,p); break; default: bfly_generic(Fout,fstride,st,m,p); break;
} }
} }

15
test/Makefile
View File

@ -1,11 +1,10 @@
ifeq "$(NFFT)" "" ifeq "$(NFFT)" ""
NFFT=1024 NFFT=1024
endif endif
ifeq "$(NUMFFTS)" "" ifeq "$(NUMFFTS)" ""
NUMFFTS=10000 NUMFFTS=10000
endif endif
UTILSRC=../kiss_fft.c fftutil.c UTILSRC=../kiss_fft.c fftutil.c
@ -13,7 +12,7 @@ UTILSRC=../kiss_fft.c fftutil.c
CFLAGS=-Wall -O3 -lm -I.. -ansi -pedantic CFLAGS=-Wall -O3 -lm -I.. -ansi -pedantic
ifeq "$(DATATYPE)" "" ifeq "$(DATATYPE)" ""
DATATYPE=float DATATYPE=float
endif endif
UTIL=fftutil_$(DATATYPE) UTIL=fftutil_$(DATATYPE)
@ -21,9 +20,9 @@ UTIL=fftutil_$(DATATYPE)
all: $(UTIL) all: $(UTIL)
ifeq "$(DATATYPE)" "short" ifeq "$(DATATYPE)" "short"
TYPEFLAGS=-DFIXED_POINT -Dkiss_fft_scalar=short TYPEFLAGS=-DFIXED_POINT -Dkiss_fft_scalar=short
else else
TYPEFLAGS=-Dkiss_fft_scalar=$(DATATYPE) TYPEFLAGS=-Dkiss_fft_scalar=$(DATATYPE)
endif endif
$(UTIL): $(UTILSRC) $(UTIL): $(UTILSRC)
@ -47,7 +46,7 @@ time: all $(RANDDAT)
POW2=256 512 1024 2048 POW2=256 512 1024 2048
POW3=243 729 2187 POW3=243 729 2187
mtime: all mtime: all
@for n in $(POW2) $(POW3) ;do \ @for n in $(POW3) ;do \
export NFFT=$$n;make time; \ export NFFT=$$n;make time; \
done done
@ -56,7 +55,7 @@ snr: all
@echo @echo
@echo "### testing SNR for $(NFFT) point FFTs" @echo "### testing SNR for $(NFFT) point FFTs"
@echo "#### $(DATATYPE)" @echo "#### $(DATATYPE)"
@echo "testkiss($(NFFT),'$(DATATYPE)',1,1/$(NFFT));" | octave -q @echo "testkiss( $(NFFT) , '$(DATATYPE)' );" | octave -q
test: snr time test: snr time

16
test/testkiss.m
View File

@ -1,11 +1,11 @@
function snr= testkiss( nfft , prec ,scale_t2f ,scale_f2t ) function snr= testkiss( nfft , prec )
if nargin<1, nfft=1024
endif if strcmp( prec ,'short')
if nargin<2, prec='float' scale_t2f=nfft;
endif scale_f2t=nfft;
if nargin<3, scale_t2f=1 else
endif scale_t2f=1;
if nargin<4, scale_f2t=1 scale_f2t=1/nfft;
endif endif
kfft= sprintf('./fftutil_%s',prec); kfft= sprintf('./fftutil_%s',prec);

15
tools/Makefile
View File

@ -1,11 +1,10 @@
ifeq "$(NFFT)" "" ifeq "$(NFFT)" ""
NFFT=1024 NFFT=1024
endif endif
ifeq "$(NUMFFTS)" "" ifeq "$(NUMFFTS)" ""
NUMFFTS=10000 NUMFFTS=10000
endif endif
UTILSRC=../kiss_fft.c fftutil.c UTILSRC=../kiss_fft.c fftutil.c
@ -13,7 +12,7 @@ UTILSRC=../kiss_fft.c fftutil.c
CFLAGS=-Wall -O3 -lm -I.. -ansi -pedantic CFLAGS=-Wall -O3 -lm -I.. -ansi -pedantic
ifeq "$(DATATYPE)" "" ifeq "$(DATATYPE)" ""
DATATYPE=float DATATYPE=float
endif endif
UTIL=fftutil_$(DATATYPE) UTIL=fftutil_$(DATATYPE)
@ -21,9 +20,9 @@ UTIL=fftutil_$(DATATYPE)
all: $(UTIL) all: $(UTIL)
ifeq "$(DATATYPE)" "short" ifeq "$(DATATYPE)" "short"
TYPEFLAGS=-DFIXED_POINT -Dkiss_fft_scalar=short TYPEFLAGS=-DFIXED_POINT -Dkiss_fft_scalar=short
else else
TYPEFLAGS=-Dkiss_fft_scalar=$(DATATYPE) TYPEFLAGS=-Dkiss_fft_scalar=$(DATATYPE)
endif endif
$(UTIL): $(UTILSRC) $(UTIL): $(UTILSRC)
@ -47,7 +46,7 @@ time: all $(RANDDAT)
POW2=256 512 1024 2048 POW2=256 512 1024 2048
POW3=243 729 2187 POW3=243 729 2187
mtime: all mtime: all
@for n in $(POW2) $(POW3) ;do \ @for n in $(POW3) ;do \
export NFFT=$$n;make time; \ export NFFT=$$n;make time; \
done done
@ -56,7 +55,7 @@ snr: all
@echo @echo
@echo "### testing SNR for $(NFFT) point FFTs" @echo "### testing SNR for $(NFFT) point FFTs"
@echo "#### $(DATATYPE)" @echo "#### $(DATATYPE)"
@echo "testkiss($(NFFT),'$(DATATYPE)',1,1/$(NFFT));" | octave -q @echo "testkiss( $(NFFT) , '$(DATATYPE)' );" | octave -q
test: snr time test: snr time