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 #include <stdint.h>
46 #if (FIXED_POINT==32)
47 # define FRACBITS 31
48 # define SAMPPROD int64_t
49 #define SAMP_MAX INT32_MAX
50 #define SAMP_MIN INT32_MIN
51 #else
52 # define FRACBITS 15
53 # define SAMPPROD int32_t
54 #define SAMP_MAX INT16_MAX
55 #define SAMP_MIN INT16_MIN
56 #endif
57 
58 #if defined(CHECK_OVERFLOW)
59 #ifdef CHRE_KISS_FFT_CAN_USE_STDIO
60 #  define CHECK_OVERFLOW_OP(a,op,b)  \
61 	if ( (SAMPPROD)(a) op (SAMPPROD)(b) > SAMP_MAX || (SAMPPROD)(a) op (SAMPPROD)(b) < SAMP_MIN ) { \
62 		fprintf(stderr,"WARNING:overflow @ " __FILE__ "(%d): (%d " #op" %d) = %ld\n",__LINE__,(a),(b),(SAMPPROD)(a) op (SAMPPROD)(b) );  }
63 #else
64 #define CHECK_OVERFLOW(a, op, b) {}
65 #endif
66 #endif
67 
68 
69 #   define smul(a,b) ( (SAMPPROD)(a)*(b) )
70 #   define sround( x )  (kiss_fft_scalar)( ( (x) + (1<<(FRACBITS-1)) ) >> FRACBITS )
71 
72 #   define S_MUL(a,b) sround( smul(a,b) )
73 
74 #   define C_MUL(m,a,b) \
75       do{ (m).r = sround( smul((a).r,(b).r) - smul((a).i,(b).i) ); \
76           (m).i = sround( smul((a).r,(b).i) + smul((a).i,(b).r) ); }while(0)
77 
78 #   define DIVSCALAR(x,k) \
79 	(x) = sround( smul(  x, SAMP_MAX/k ) )
80 
81 #   define C_FIXDIV(c,div) \
82 	do {    DIVSCALAR( (c).r , div);  \
83 		DIVSCALAR( (c).i  , div); }while (0)
84 
85 #   define C_MULBYSCALAR( c, s ) \
86     do{ (c).r =  sround( smul( (c).r , s ) ) ;\
87         (c).i =  sround( smul( (c).i , s ) ) ; }while(0)
88 
89 #else  /* not FIXED_POINT*/
90 
91 #   define S_MUL(a,b) ( (a)*(b) )
92 #define C_MUL(m,a,b) \
93     do{ (m).r = (a).r*(b).r - (a).i*(b).i;\
94         (m).i = (a).r*(b).i + (a).i*(b).r; }while(0)
95 #   define C_FIXDIV(c,div) /* NOOP */
96 #   define C_MULBYSCALAR( c, s ) \
97     do{ (c).r *= (s);\
98         (c).i *= (s); }while(0)
99 #endif
100 
101 #ifndef CHECK_OVERFLOW_OP
102 #  define CHECK_OVERFLOW_OP(a,op,b) /* noop */
103 #endif
104 
105 #define  C_ADD( res, a,b)\
106     do { \
107 	    CHECK_OVERFLOW_OP((a).r,+,(b).r)\
108 	    CHECK_OVERFLOW_OP((a).i,+,(b).i)\
109 	    (res).r=(a).r+(b).r;  (res).i=(a).i+(b).i; \
110     }while(0)
111 #define  C_SUB( res, a,b)\
112     do { \
113 	    CHECK_OVERFLOW_OP((a).r,-,(b).r)\
114 	    CHECK_OVERFLOW_OP((a).i,-,(b).i)\
115 	    (res).r=(a).r-(b).r;  (res).i=(a).i-(b).i; \
116     }while(0)
117 #define C_ADDTO( res , a)\
118     do { \
119 	    CHECK_OVERFLOW_OP((res).r,+,(a).r)\
120 	    CHECK_OVERFLOW_OP((res).i,+,(a).i)\
121 	    (res).r += (a).r;  (res).i += (a).i;\
122     }while(0)
123 
124 #define C_SUBFROM( res , a)\
125     do {\
126 	    CHECK_OVERFLOW_OP((res).r,-,(a).r)\
127 	    CHECK_OVERFLOW_OP((res).i,-,(a).i)\
128 	    (res).r -= (a).r;  (res).i -= (a).i; \
129     }while(0)
130 
131 
132 #ifdef FIXED_POINT
133 #  define KISS_FFT_COS(phase)  floor(.5+SAMP_MAX * cos (phase))
134 #  define KISS_FFT_SIN(phase)  floor(.5+SAMP_MAX * sin (phase))
135 #  define HALF_OF(x) ((x)>>1)
136 #elif defined(USE_SIMD)
137 #  define KISS_FFT_COS(phase) _mm_set1_ps( cos(phase) )
138 #  define KISS_FFT_SIN(phase) _mm_set1_ps( sin(phase) )
139 #  define HALF_OF(x) ((x)*_mm_set1_ps(.5))
140 #else
141 #  define KISS_FFT_COS(phase) (kiss_fft_scalar) cos(phase)
142 #  define KISS_FFT_SIN(phase) (kiss_fft_scalar) sin(phase)
143 #  define HALF_OF(x) ((x)*.5)
144 #endif
145 
146 #define  kf_cexp(x,phase) \
147 	do{ \
148 		(x)->r = (int16_t)KISS_FFT_COS(phase);\
149 		(x)->i = (int16_t)KISS_FFT_SIN(phase);\
150 	}while(0)
151 
152 
153 #ifdef CHRE_KISS_FFT_CAN_USE_STDIO
154 /* a debugging function */
155 #define pcpx(c)\
156     fprintf(stderr,"%g + %gi\n",(double)((c)->r),(double)((c)->i) )
157 #else
158 #define pcpx(c) {}
159 #endif
160 
161 #ifdef KISS_FFT_USE_ALLOCA
162 // define this to allow use of alloca instead of malloc for temporary buffers
163 // Temporary buffers are used in two case:
164 // 1. FFT sizes that have "bad" factors. i.e. not 2,3 and 5
165 // 2. "in-place" FFTs.  Notice the quotes, since kissfft does not really do an in-place transform.
166 #include <alloca.h>
167 #define  KISS_FFT_TMP_ALLOC(nbytes) alloca(nbytes)
168 #define  KISS_FFT_TMP_FREE(ptr)
169 #else
170 #define  KISS_FFT_TMP_ALLOC(nbytes) KISS_FFT_MALLOC(nbytes)
171 #define  KISS_FFT_TMP_FREE(ptr) KISS_FFT_FREE(ptr)
172 #endif
173