SphinxBase  0.6
fixpoint.h
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35 
36 /* Fixed-point arithmetic macros.
37  *
38  * Author: David Huggins-Daines <dhuggins@cs.cmu.edu>
39  */
40 
41 #ifndef _FIXPOINT_H_
42 #define _FIXPOINT_H_
43 
44 #include <limits.h>
45 
46 /* Win32/WinCE DLL gunk */
47 #include <sphinxbase/sphinxbase_export.h>
48 #include <sphinxbase/prim_type.h>
49 
50 #ifdef __cplusplus
51 extern "C" {
52 #endif
53 #if 0
54 /* Fool Emacs. */
55 }
56 #endif
57 
58 #ifndef DEFAULT_RADIX
59 #define DEFAULT_RADIX 12
60 #endif
61 
63 typedef int32 fixed32;
64 
66 #define FLOAT2FIX_ANY(x,radix) \
67  (((x)<0.0) ? \
68  ((fixed32)((x)*(float32)(1<<(radix)) - 0.5)) \
69  : ((fixed32)((x)*(float32)(1<<(radix)) + 0.5)))
70 #define FLOAT2FIX(x) FLOAT2FIX_ANY(x,DEFAULT_RADIX)
71 
72 #define FIX2FLOAT_ANY(x,radix) ((float32)(x)/(1<<(radix)))
73 #define FIX2FLOAT(x) FIX2FLOAT_ANY(x,DEFAULT_RADIX)
74 
83 /*
84  * This works on most modern ARMs but *only* in ARM mode (for obvious
85  * reasons), so don't use it in Thumb mode (but why are you building
86  * signal processing code in Thumb mode?!)
87  */
88 #if defined(__arm__) && !defined(__thumb__)
89 #define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX)
90 #define FIXMUL_ANY(a,b,r) ({ \
91  int cl, ch, _a = a, _b = b; \
92  __asm__ ("smull %0, %1, %2, %3\n" \
93  "mov %0, %0, lsr %4\n" \
94  "orr %0, %0, %1, lsl %5\n" \
95  : "=&r" (cl), "=&r" (ch) \
96  : "r" (_a), "r" (_b), "i" (r), "i" (32-(r)));\
97  cl; })
98 #elif defined(BFIN) && DEFAULT_RADIX == 16
99 /* Blackfin magic */
100 #undef FIXMUL
101 /* Use the accumulators for the 16.16 case (probably not as efficient as it could be). */
102 #define FIXMUL(a,b) ({ \
103  int c, _a = a, _b = b; \
104  __asm__("%0.L = %1.l * %2.l (FU);\n\t" \
105  "%0.H = %1.h * %2.h (IS);\n\t" \
106  "A1 = %0;\n\t" \
107  "A1 += %1.h * %2.l (IS, M);\n\t" \
108  "%0 = (A1 += %2.h * %1.l) (IS, M);\n\t" \
109  : "=&W" (c) \
110  : "d" (_a), "d" (_b) \
111  : "A1", "cc"); \
112  c; })
113 #define FIXMUL_ANY(a,b,radix) ((fixed32)(((int64)(a)*(b))>>(radix)))
114 #elif defined(_MSC_VER) || (defined(HAVE_LONG_LONG) && SIZEOF_LONG_LONG == 8)
115 #define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX)
116 #define FIXMUL_ANY(a,b,radix) ((fixed32)(((int64)(a)*(b))>>(radix)))
117 #else /* Most general case where 'long long' doesn't exist or is slow. */
118 #define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX)
119 #define FIXMUL_ANY(a,b,radix) \
120  (fixed32)(((((uint32)(a))&((1<<(radix))-1)) \
121  * (((uint32)(b))&((1<<(radix))-1)) >> (radix)) \
122  + (((((int32)(a))>>(radix)) * (((int32)(b))>>(radix))) << (radix)) \
123  + ((((uint32)(a))&((1<<(radix))-1)) * (((int32)(b))>>(radix))) \
124  + ((((uint32)(b))&((1<<(radix))-1)) * (((int32)(a))>>(radix))))
125 #endif
126 
127 /* Various fixed-point logarithmic functions that we need. */
129 #define MIN_FIXLOG -2829416 /* log(1e-300) * (1<<DEFAULT_RADIX) */
130 #define MIN_FIXLOG2 -4081985 /* log2(1e-300) * (1<<DEFAULT_RADIX) */
131 
132 #define FIXLN_2 ((fixed32)(0.693147180559945 * (1<<DEFAULT_RADIX)))
133 
134 #define FIXLN(x) (fixlog(x) - (FIXLN_2 * DEFAULT_RADIX))
135 
139 int32 fixlog(uint32 x);
144 int32 fixlog2(uint32 x);
145 
146 #ifdef __cplusplus
147 }
148 #endif
149 
150 
151 #endif /* _FIXPOINT_H_ */
Basic type definitions used in Sphinx.