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Diffstat (limited to 'media/sphinxbase/sphinxbase/fixpoint.h')
| -rw-r--r-- | media/sphinxbase/sphinxbase/fixpoint.h | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/media/sphinxbase/sphinxbase/fixpoint.h b/media/sphinxbase/sphinxbase/fixpoint.h new file mode 100644 index 000000000..30b5cb202 --- /dev/null +++ b/media/sphinxbase/sphinxbase/fixpoint.h @@ -0,0 +1,145 @@ +/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */ +/* ==================================================================== + * Copyright (c) 2005 Carnegie Mellon University. All rights + * reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. 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. + * + * This work was supported in part by funding from the Defense Advanced + * Research Projects Agency and the National Science Foundation of the + * United States of America, and the CMU Sphinx Speech Consortium. + * + * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND + * ANY EXPRESSED 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 CARNEGIE MELLON UNIVERSITY + * NOR ITS EMPLOYEES 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. + * + * ==================================================================== */ + +/* Fixed-point arithmetic macros. + * + * Author: David Huggins-Daines <dhuggins@cs.cmu.edu> + */ + +#ifndef _FIXPOINT_H_ +#define _FIXPOINT_H_ + +#include <limits.h> + +/* Win32/WinCE DLL gunk */ +#include <sphinxbase/sphinxbase_export.h> +#include <sphinxbase/prim_type.h> + +#ifdef __cplusplus +extern "C" { +#endif +#if 0 +/* Fool Emacs. */ +} +#endif + +#ifndef DEFAULT_RADIX +#define DEFAULT_RADIX 12 +#endif + +/** Fixed-point computation type. */ +typedef int32 fixed32; + +/** Convert floating point to fixed point. */ +#define FLOAT2FIX_ANY(x,radix) \ + (((x)<0.0) ? \ + ((fixed32)((x)*(float32)(1<<(radix)) - 0.5)) \ + : ((fixed32)((x)*(float32)(1<<(radix)) + 0.5))) +#define FLOAT2FIX(x) FLOAT2FIX_ANY(x,DEFAULT_RADIX) +/** Convert fixed point to floating point. */ +#define FIX2FLOAT_ANY(x,radix) ((float32)(x)/(1<<(radix))) +#define FIX2FLOAT(x) FIX2FLOAT_ANY(x,DEFAULT_RADIX) + +/** + * Multiply two fixed point numbers with an arbitrary radix point. + * + * A veritable multiplicity of implementations exist, starting with + * the fastest ones... + */ + +#if defined(__arm__) && !defined(__thumb__) +/* + * This works on most modern ARMs but *only* in ARM mode (for obvious + * reasons), so don't use it in Thumb mode (but why are you building + * signal processing code in Thumb mode?!) + */ +#define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX) +#define FIXMUL_ANY(a,b,r) ({ \ + int cl, ch, _a = a, _b = b; \ + __asm__ ("smull %0, %1, %2, %3\n" \ + "mov %0, %0, lsr %4\n" \ + "orr %0, %0, %1, lsl %5\n" \ + : "=&r" (cl), "=&r" (ch) \ + : "r" (_a), "r" (_b), "i" (r), "i" (32-(r)));\ + cl; }) + +#elif defined(_MSC_VER) || (defined(HAVE_LONG_LONG) && SIZEOF_LONG_LONG == 8) +/* Standard systems*/ +#define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX) +#define FIXMUL_ANY(a,b,radix) ((fixed32)(((int64)(a)*(b))>>(radix))) + +#else +/* Most general case where 'long long' doesn't exist or is slow. */ +#define FIXMUL(a,b) FIXMUL_ANY(a,b,DEFAULT_RADIX) +#define FIXMUL_ANY(a,b,radix) ({ \ + int32 _ah, _bh; \ + uint32 _al, _bl, _t, c; \ + _ah = ((int32)(a)) >> 16; \ + _bh = ((int32)(b)) >> 16; \ + _al = ((uint32)(a)) & 0xffff; \ + _bl = ((uint32)(b)) & 0xffff; \ + _t = _ah * _bl + _al * _bh; \ + c = (fixed32)(((_al * _bl) >> (radix)) \ + + ((_ah * _bh) << (32 - (radix))) \ + + ((radix) > 16 ? (_t >> (radix - 16)) : (_t << (16 - radix)))); \ + c;}) +#endif + +/* Various fixed-point logarithmic functions that we need. */ +/** Minimum value representable in log format. */ +#define MIN_FIXLOG -2829416 /* log(1e-300) * (1<<DEFAULT_RADIX) */ +#define MIN_FIXLOG2 -4081985 /* log2(1e-300) * (1<<DEFAULT_RADIX) */ +/** Fixed-point representation of log(2) */ +#define FIXLN_2 ((fixed32)(0.693147180559945 * (1<<DEFAULT_RADIX))) +/** Take natural logarithm of a fixedpoint number. */ +#define FIXLN(x) (fixlog(x) - (FIXLN_2 * DEFAULT_RADIX)) + +/** + * Take natural logarithm of an integer, yielding a fixedpoint number + * with DEFAULT_RADIX as radix point. + */ +int32 fixlog(uint32 x); +/** + * Take base-2 logarithm of an integer, yielding a fixedpoint number + * with DEFAULT_RADIX as radix point. + */ +int32 fixlog2(uint32 x); + +#ifdef __cplusplus +} +#endif + + +#endif /* _FIXPOINT_H_ */ |