libhoomd/extern/_kiss_fft_guts.h

   1 /*
   2 Copyright (c) 2003-2010, Mark Borgerding
   3
   4 All rights reserved.
   5
   6 Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
   7
   8     * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
   9     * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
  10     * Neither the author nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.
  11
  12 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  13 */
  14
  15 /* kiss_fft.h
  16    defines kiss_fft_scalar as either short or a float type
  17    and defines
  18    typedef struct { kiss_fft_scalar r; kiss_fft_scalar i; }kiss_fft_cpx; */
  19 #include "kiss_fft.h"
  20 #include <limits.h>
  21
  22 #define MAXFACTORS 32
  23 /* e.g. an fft of length 128 has 4 factors
  24  as far as kissfft is concerned
  25  4*4*4*2
  26  */
  27
  28 struct kiss_fft_state{
  29     int nfft;
  30     int inverse;
  31     int factors[2*MAXFACTORS];
  32     kiss_fft_cpx twiddles[1];
  33 };
  34
  35 /*
  36   Explanation of macros dealing with complex math:
  37
  38    C_MUL(m,a,b)         : m = a*b
  39    C_FIXDIV( c , div )  : if a fixed point impl., c /= div. noop otherwise
  40    C_SUB( res, a,b)     : res = a - b
  41    C_SUBFROM( res , a)  : res -= a
  42    C_ADDTO( res , a)    : res += a
  43  * */
  44 #ifdef FIXED_POINT
  45 #if (FIXED_POINT==32)
  46 # define FRACBITS 31
  47 # define SAMPPROD int64_t
  48 #define SAMP_MAX 2147483647
  49 #else
  50 # define FRACBITS 15
  51 # define SAMPPROD int32_t
  52 #define SAMP_MAX 32767
  53 #endif
  54
  55 #define SAMP_MIN -SAMP_MAX
  56
  57 #if defined(CHECK_OVERFLOW)
  58 #  define CHECK_OVERFLOW_OP(a,op,b)  \
  59     if ( (SAMPPROD)(a) op (SAMPPROD)(b) > SAMP_MAX || (SAMPPROD)(a) op (SAMPPROD)(b) < SAMP_MIN ) { \
  60         fprintf(stderr,"WARNING:overflow @ " __FILE__ "(%d): (%d " #op" %d) = %ld\n",__LINE__,(a),(b),(SAMPPROD)(a) op (SAMPPROD)(b) );  }
  61 #endif
  62
  63
  64 #   define smul(a,b) ( (SAMPPROD)(a)*(b) )
  65 #   define sround( x )  (kiss_fft_scalar)( ( (x) + (1<<(FRACBITS-1)) ) >> FRACBITS )
  66
  67 #   define S_MUL(a,b) sround( smul(a,b) )
  68
  69 #   define C_MUL(m,a,b) \
  70       do{ (m).r = sround( smul((a).r,(b).r) - smul((a).i,(b).i) ); \
  71           (m).i = sround( smul((a).r,(b).i) + smul((a).i,(b).r) ); }while(0)
  72
  73 #   define DIVSCALAR(x,k) \
  74     (x) = sround( smul(  x, SAMP_MAX/k ) )
  75
  76 #   define C_FIXDIV(c,div) \
  77     do {    DIVSCALAR( (c).r , div);  \
  78         DIVSCALAR( (c).i  , div); }while (0)
  79
  80 #   define C_MULBYSCALAR( c, s ) \
  81     do{ (c).r =  sround( smul( (c).r , s ) ) ;\
  82         (c).i =  sround( smul( (c).i , s ) ) ; }while(0)
  83
  84 #else  /* not FIXED_POINT*/
  85
  86 #   define S_MUL(a,b) ( (a)*(b) )
  87 #define C_MUL(m,a,b) \
  88     do{ (m).r = (a).r*(b).r - (a).i*(b).i;\
  89         (m).i = (a).r*(b).i + (a).i*(b).r; }while(0)
  90 #   define C_FIXDIV(c,div) /* NOOP */
  91 #   define C_MULBYSCALAR( c, s ) \
  92     do{ (c).r *= (s);\
  93         (c).i *= (s); }while(0)
  94 #endif
  95
  96 #ifndef CHECK_OVERFLOW_OP
  97 #  define CHECK_OVERFLOW_OP(a,op,b) /* noop */
  98 #endif
  99
 100 #define  C_ADD( res, a,b)\
 101     do { \
 102         CHECK_OVERFLOW_OP((a).r,+,(b).r)\
 103         CHECK_OVERFLOW_OP((a).i,+,(b).i)\
 104         (res).r=(a).r+(b).r;  (res).i=(a).i+(b).i; \
 105     }while(0)
 106 #define  C_SUB( res, a,b)\
 107     do { \
 108         CHECK_OVERFLOW_OP((a).r,-,(b).r)\
 109         CHECK_OVERFLOW_OP((a).i,-,(b).i)\
 110         (res).r=(a).r-(b).r;  (res).i=(a).i-(b).i; \
 111     }while(0)
 112 #define C_ADDTO( res , a)\
 113     do { \
 114         CHECK_OVERFLOW_OP((res).r,+,(a).r)\
 115         CHECK_OVERFLOW_OP((res).i,+,(a).i)\
 116         (res).r += (a).r;  (res).i += (a).i;\
 117     }while(0)
 118
 119 #define C_SUBFROM( res , a)\
 120     do {\
 121         CHECK_OVERFLOW_OP((res).r,-,(a).r)\
 122         CHECK_OVERFLOW_OP((res).i,-,(a).i)\
 123         (res).r -= (a).r;  (res).i -= (a).i; \
 124     }while(0)
 125
 126
 127 #ifdef FIXED_POINT
 128 #  define KISS_FFT_COS(phase)  floor(.5+SAMP_MAX * cos (phase))
 129 #  define KISS_FFT_SIN(phase)  floor(.5+SAMP_MAX * sin (phase))
 130 #  define HALF_OF(x) ((x)>>1)
 131 #elif defined(USE_SIMD)
 132 #  define KISS_FFT_COS(phase) _mm_set1_ps( cos(phase) )
 133 #  define KISS_FFT_SIN(phase) _mm_set1_ps( sin(phase) )
 134 #  define HALF_OF(x) ((x)*_mm_set1_ps(.5))
 135 #else
 136 #  define KISS_FFT_COS(phase) (kiss_fft_scalar) cos(phase)
 137 #  define KISS_FFT_SIN(phase) (kiss_fft_scalar) sin(phase)
 138 #  define HALF_OF(x) ((x)*.5)
 139 #endif
 140
 141 #define  kf_cexp(x,phase) \
 142     do{ \
 143         (x)->r = KISS_FFT_COS(phase);\
 144         (x)->i = KISS_FFT_SIN(phase);\
 145     }while(0)
 146
 147
 148 /* a debugging function */
 149 #define pcpx(c)\
 150     fprintf(stderr,"%g + %gi\n",(double)((c)->r),(double)((c)->i) )
 151
 152
 153 #ifdef KISS_FFT_USE_ALLOCA
 154 // define this to allow use of alloca instead of malloc for temporary buffers
 155 // Temporary buffers are used in two case:
 156 // 1. FFT sizes that have "bad" factors. i.e. not 2,3 and 5
 157 // 2. "in-place" FFTs.  Notice the quotes, since kissfft does not really do an in-place transform.
 158 #include <alloca.h>
 159 #define  KISS_FFT_TMP_ALLOC(nbytes) alloca(nbytes)
 160 #define  KISS_FFT_TMP_FREE(ptr)
 161 #else
 162 #define  KISS_FFT_TMP_ALLOC(nbytes) KISS_FFT_MALLOC(nbytes)
 163 #define  KISS_FFT_TMP_FREE(ptr) KISS_FFT_FREE(ptr)
 164 #endif