/* * libmad - MPEG audio decoder library * Copyright (C) 2000-2004 Underbit Technologies, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * * $Id: fixed.h,v 1.38 2004/02/17 02:02:03 rob Exp $ */# ifndef LIBMAD_FIXED_H# define LIBMAD_FIXED_H# if SIZEOF_INT >= 4typedef   signed int mad_fixed_t;typedef   signed int mad_fixed64hi_t;typedef unsigned int mad_fixed64lo_t;# elsetypedef   signed long mad_fixed_t;typedef   signed long mad_fixed64hi_t;typedef unsigned long mad_fixed64lo_t;# endif# if defined(_MSC_VER)#  define mad_fixed64_t  signed __int64# elif 1 || defined(__GNUC__)#  define mad_fixed64_t  signed long long# endif# if defined(FPM_FLOAT)typedef double mad_sample_t;# elsetypedef mad_fixed_t mad_sample_t;# endif/* * Fixed-point format: 0xABBBBBBB * A == whole part      (sign + 3 bits) * B == fractional part (28 bits) * * Values are signed two's complement, so the effective range is: * 0x80000000 to 0x7fffffff *       -8.0 to +7.9999999962747097015380859375 * * The smallest representable value is: * 0x00000001 == 0.0000000037252902984619140625 (i.e. about 3.725e-9) * * 28 bits of fractional accuracy represent about * 8.6 digits of decimal accuracy. * * Fixed-point numbers can be added or subtracted as normal * integers, but multiplication requires shifting the 64-bit result * from 56 fractional bits back to 28 (and rounding.) * * Changing the definition of MAD_F_FRACBITS is only partially * supported, and must be done with care. */# define MAD_F_FRACBITS		28# if MAD_F_FRACBITS == 28#  define MAD_F(x)		((mad_fixed_t) (x##L))# else#  if MAD_F_FRACBITS < 28#   warning "MAD_F_FRACBITS < 28"#   define MAD_F(x)		((mad_fixed_t)  \				 (((x##L) +  \				   (1L << (28 - MAD_F_FRACBITS - 1))) >>  \				  (28 - MAD_F_FRACBITS)))#  elif MAD_F_FRACBITS > 28#   error "MAD_F_FRACBITS > 28 not currently supported"#   define MAD_F(x)		((mad_fixed_t)  \				 ((x##L) << (MAD_F_FRACBITS - 28)))#  endif# endif# define MAD_F_MIN		((mad_fixed_t) -0x80000000L)# define MAD_F_MAX		((mad_fixed_t) +0x7fffffffL)# define MAD_F_ONE		MAD_F(0x10000000)# define mad_f_tofixed(x)	((mad_fixed_t)  \				 ((x) * (double) (1L << MAD_F_FRACBITS) + 0.5))# define mad_f_todouble(x)	((double)  \				 ((x) / (double) (1L << MAD_F_FRACBITS)))# define mad_f_intpart(x)	((x) >> MAD_F_FRACBITS)# define mad_f_fracpart(x)	((x) & ((1L << MAD_F_FRACBITS) - 1))				/* (x should be positive) */# define mad_f_fromint(x)	((x) << MAD_F_FRACBITS)# define mad_f_add(x, y)	((x) + (y))# define mad_f_sub(x, y)	((x) - (y))# if defined(FPM_FLOAT)#  error "FPM_FLOAT not yet supported"#  undef MAD_F#  define MAD_F(x)		mad_f_todouble(x)#  define mad_f_mul(x, y)	((x) * (y))#  define mad_f_scale64#  undef ASO_ZEROCHECK# elif defined(FPM_64BIT)/* * This version should be the most accurate if 64-bit types are supported by * the compiler, although it may not be the most efficient. *///#  if defined(OPT_ACCURACY)//#   define mad_f_mul(x, y)  \    ((mad_fixed_t)  \     ((((mad_fixed64_t) (x) * (y)) +  \       (1L << (MAD_F_SCALEBITS - 1))) >> MAD_F_SCALEBITS))//#  else#   define mad_f_mul(x, y)  \    ((mad_fixed_t) (((mad_fixed64_t) (x) * (y)) >> MAD_F_SCALEBITS))//#  endif#  define MAD_F_SCALEBITS  MAD_F_FRACBITS/* --- Intel --------------------------------------------------------------- */#  define MAD_F_SCALEBITS  MAD_F_FRACBITS/* --- Default ------------------------------------------------------------- */# elif defined(FPM_DEFAULT)/* * This version is the most portable but it loses significant accuracy. * Furthermore, accuracy is biased against the second argument, so care * should be taken when ordering operands. * * The scale factors are constant as this is not used with SSO. * * Pre-rounding is required to stay within the limits of compliance. *///#  if defined(OPT_SPEED)***********************************//#   define mad_f_mul(x, y)	(((x) >> 12) * ((y) >> 16))//#  else#   define mad_f_mul(x, y)	((((x) + (1L << 11)) >> 12) *  \				 (((y) + (1L << 15)) >> 16))//#  endif****************************************************/* ------------------------------------------------------------------------- *///# else******************************************************//#  error "no FPM selected"**********************************# endif/* default implementations *//**************************************************************# if !defined(mad_f_mul)#  define mad_f_mul(x, y)  \    ({ register mad_fixed64hi_t __hi;  \       register mad_fixed64lo_t __lo;  \       MAD_F_MLX(__hi, __lo, (x), (y));  \       mad_f_scale64(__hi, __lo);  \    })# endif*/# if !defined(MAD_F_MLA)#  define MAD_F_ML0(hi, lo, x, y)	((lo)  = mad_f_mul((x), (y)))#  define MAD_F_MLA(hi, lo, x, y)	((lo) += mad_f_mul((x), (y)))#  define MAD_F_MLN(hi, lo)		((lo)  = -(lo))#  define MAD_F_MLZ(hi, lo)		((void) (hi), (mad_fixed_t) (lo))# endif//# if !defined(MAD_F_ML0)********************************//#  define MAD_F_ML0(hi, lo, x, y)	MAD_F_MLX((hi), (lo), (x), (y))//# endif************************************************# if !defined(MAD_F_MLN)#  define MAD_F_MLN(hi, lo)		((hi) = ((lo) = -(lo)) ? ~(hi) : -(hi))# endif# if !defined(MAD_F_MLZ)#  define MAD_F_MLZ(hi, lo)		mad_f_scale64((hi), (lo))# endif# if !defined(mad_f_scale64)#  if defined(OPT_ACCURACY)#   define mad_f_scale64(hi, lo)  \    ((((mad_fixed_t)  \       (((hi) << (32 - (MAD_F_SCALEBITS - 1))) |  \	((lo) >> (MAD_F_SCALEBITS - 1)))) + 1) >> 1)#  else#   define mad_f_scale64(hi, lo)  \    ((mad_fixed_t)  \     (((hi) << (32 - MAD_F_SCALEBITS)) |  \      ((lo) >> MAD_F_SCALEBITS)))#  endif#  define MAD_F_SCALEBITS  MAD_F_FRACBITS# endif/* C routines */mad_fixed_t mad_f_abs(mad_fixed_t);mad_fixed_t mad_f_div(mad_fixed_t, mad_fixed_t);# endif