SphinxBase 5prealpha
fixpoint.h
1/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
2/* ====================================================================
3 * Copyright (c) 2005 Carnegie Mellon University. All rights
4 * reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 *
18 * This work was supported in part by funding from the Defense Advanced
19 * Research Projects Agency and the National Science Foundation of the
20 * United States of America, and the CMU Sphinx Speech Consortium.
21 *
22 * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND
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34 * ==================================================================== */
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>
49
50#ifdef __cplusplus
51extern "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
63typedef 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)
72#define FIX2FLOAT_ANY(x,radix) ((float32)(x)/(1<<(radix)))
73#define FIX2FLOAT(x) FIX2FLOAT_ANY(x,DEFAULT_RADIX)
74
82#if defined(__arm__) && !defined(__thumb__)
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#define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX)
89#define FIXMUL_ANY(a,b,r) ({ \
90 int cl, ch, _a = a, _b = b; \
91 __asm__ ("smull %0, %1, %2, %3\n" \
92 "mov %0, %0, lsr %4\n" \
93 "orr %0, %0, %1, lsl %5\n" \
94 : "=&r" (cl), "=&r" (ch) \
95 : "r" (_a), "r" (_b), "i" (r), "i" (32-(r)));\
96 cl; })
97
98#elif defined(_MSC_VER) || (defined(HAVE_LONG_LONG) && SIZEOF_LONG_LONG == 8)
99/* Standard systems*/
100#define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX)
101#define FIXMUL_ANY(a,b,radix) ((fixed32)(((int64)(a)*(b))>>(radix)))
102
103#else
104/* Most general case where 'long long' doesn't exist or is slow. */
105#define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX)
106#define FIXMUL_ANY(a,b,radix) ({ \
107 int32 _ah, _bh; \
108 uint32 _al, _bl, _t, c; \
109 _ah = ((int32)(a)) >> 16; \
110 _bh = ((int32)(b)) >> 16; \
111 _al = ((uint32)(a)) & 0xffff; \
112 _bl = ((uint32)(b)) & 0xffff; \
113 _t = _ah * _bl + _al * _bh; \
114 c = (fixed32)(((_al * _bl) >> (radix)) \
115 + ((_ah * _bh) << (32 - (radix))) \
116 + ((radix) > 16 ? (_t >> (radix - 16)) : (_t << (16 - radix)))); \
117 c;})
118#endif
119
120/* Various fixed-point logarithmic functions that we need. */
122#define MIN_FIXLOG -2829416 /* log(1e-300) * (1<<DEFAULT_RADIX) */
123#define MIN_FIXLOG2 -4081985 /* log2(1e-300) * (1<<DEFAULT_RADIX) */
125#define FIXLN_2 ((fixed32)(0.693147180559945 * (1<<DEFAULT_RADIX)))
127#define FIXLN(x) (fixlog(x) - (FIXLN_2 * DEFAULT_RADIX))
128
133int32 fixlog(uint32 x);
138int32 fixlog2(uint32 x);
139
140#ifdef __cplusplus
141}
142#endif
143
144
145#endif /* _FIXPOINT_H_ */
Basic type definitions used in Sphinx.