Point Cloud Library (PCL)  1.9.1-dev
_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  struct kiss_fft_cpx { kiss_fft_scalar r; kiss_fft_scalar i; }; */
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 
29  int nfft;
30  int inverse;
31  int factors[2*MAXFACTORS];
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
int factors[2 *MAXFACTORS]
kiss_fft_cpx twiddles[1]