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made easy to use longs for fixed point

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This commit is contained in:
Mark Borgerding
2005-05-11 02:36:33 +00:00
parent ba105600b4
commit ed1a5f0cfc
5 changed files with 141 additions and 14 deletions
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34
_kiss_fft_guts.h
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@ -17,7 +17,7 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
and defines
typedef struct { kiss_fft_scalar r; kiss_fft_scalar i; }kiss_fft_cpx; */
#include "kiss_fft.h"
#include <limits.h>
#define MAXFACTORS 32
/* e.g. an fft of length 128 has 4 factors
@ -42,16 +42,28 @@ struct kiss_fft_state{
C_ADDTO( res , a) : res += a
* */
#ifdef FIXED_POINT
#if defined(CHECK_OVERFLOW)
# define CHECK_OVERFLOW_OP(a,op,b) \
if ( (long)(a) op (long)(b) > 32767 || (long)(a) op (long)(b) < -32768 ) { \
fprintf(stderr,"WARNING:overflow @ " __FILE__ "(%d): (%d " #op" %d) = %ld\n",__LINE__,(a),(b),(long)(a) op (long)(b) ); }
#if (FIXED_POINT==32)
# define FRACBITS 31
# define SAMPPROD long long
#define SAMP_MAX LONG_MAX
#define SAMP_MIN LONG_MIN
#else
# define FRACBITS 15
# define SAMPPROD long
#define SAMP_MAX SHRT_MAX
#define SAMP_MIN SHRT_MIN
#endif
# define smul(a,b) ( (long)(a)*(b) )
# define sround( x ) (short)( ( (x) + (1<<14) ) >>15 )
#if defined(CHECK_OVERFLOW)
# define CHECK_OVERFLOW_OP(a,op,b) \
if ( (SAMPPROD)(a) op (SAMPPROD)(b) > SAMP_MAX || (SAMPPROD)(a) op (SAMPPROD)(b) < SAMP_MIN ) { \
fprintf(stderr,"WARNING:overflow @ " __FILE__ "(%d): (%d " #op" %d) = %ld\n",__LINE__,(a),(b),(SAMPPROD)(a) op (SAMPPROD)(b) ); }
#endif
# define smul(a,b) ( (SAMPPROD)(a)*(b) )
# define sround( x ) (kiss_fft_scalar)( ( (x) + (1<<(FRACBITS-1)) ) >> FRACBITS )
# define S_MUL(a,b) sround( smul(a,b) )
@ -60,7 +72,7 @@ struct kiss_fft_state{
(m).i = sround( smul((a).r,(b).i) + smul((a).i,(b).r) ); }while(0)
# define DIVSCALAR(x,k) \
(x) = sround( smul( x, 32767/k ) )
(x) = sround( smul( x, SAMP_MAX/k ) )
# define C_FIXDIV(c,div) \
do { DIVSCALAR( (c).r , div); \
@ -119,8 +131,8 @@ static
void kf_cexp(kiss_fft_cpx * x,double phase) /* returns e ** (j*phase) */
{
#ifdef FIXED_POINT
x->r = (kiss_fft_scalar) (32767 * cos (phase));
x->i = (kiss_fft_scalar) (32767 * sin (phase));
x->r = (kiss_fft_scalar) (SAMP_MAX * cos (phase));
x->i = (kiss_fft_scalar) (SAMP_MAX * sin (phase));
#else
x->r = cos (phase);
x->i = sin (phase);