/* * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #ifndef AVUTIL_SOFTFLOAT_H#define AVUTIL_SOFTFLOAT_H #include <stdint.h>#include "common.h" #define MIN_EXP -126#define MAX_EXP  126#define ONE_BITS 29 typedef struct SoftFloat{    int32_t  exp;    int32_t mant;}SoftFloat; static av_const SoftFloat av_normalize_sf(SoftFloat a){    if(a.mant){#if 1        while((a.mant + 0x20000000U)<0x40000000U){            a.mant += a.mant;            a.exp  -= 1;        }#else        int s=ONE_BITS + 1 - av_log2(a.mant ^ (a.mant<<1));        a.exp   -= s;        a.mant <<= s;#endif        if(a.exp < MIN_EXP){            a.exp = MIN_EXP;            a.mant= 0;        }    }else{        a.exp= MIN_EXP;    }    return a;} static inline av_const SoftFloat av_normalize1_sf(SoftFloat a){#if 1    if(a.mant + 0x40000000 < 0){        a.exp++;        a.mant>>=1;    }    return a;#elif 1    int t= a.mant + 0x40000000 < 0;    return (SoftFloat){a.exp+t, a.mant>>t};#else    int t= (a.mant + 0x40000000U)>>31;    return (SoftFloat){a.exp+t, a.mant>>t};#endif} /** * @return Will not be more denormalized than a+b. So if either input is *         normalized, then the output will not be worse then the other input. *         If both are normalized, then the output will be normalized. */static inline av_const SoftFloat av_mul_sf(SoftFloat a, SoftFloat b){    a.exp += b.exp;    a.mant = (a.mant * (int64_t)b.mant) >> ONE_BITS;    return av_normalize1_sf(a);} /** * b has to be normalized and not zero. * @return Will not be more denormalized than a. */static av_const SoftFloat av_div_sf(SoftFloat a, SoftFloat b){    a.exp -= b.exp+1;    a.mant = ((int64_t)a.mant<<(ONE_BITS+1)) / b.mant;    return av_normalize1_sf(a);} static inline av_const int av_cmp_sf(SoftFloat a, SoftFloat b){    int t= a.exp - b.exp;    if(t<0) return (a.mant >> (-t)) -  b.mant      ;    else    return  a.mant          - (b.mant >> t);} static inline av_const SoftFloat av_add_sf(SoftFloat a, SoftFloat b){    int t= a.exp - b.exp;    if(t<0) return av_normalize1_sf((SoftFloat){b.exp, b.mant + (a.mant >> (-t))});    else    return av_normalize1_sf((SoftFloat){a.exp, a.mant + (b.mant >>   t )});} static inline av_const SoftFloat av_sub_sf(SoftFloat a, SoftFloat b){    return av_add_sf(a, (SoftFloat){b.exp, -b.mant});} //FIXME sqrt, log, exp, pow, sin, cos static inline av_const SoftFloat av_int2sf(int v, int frac_bits){    return av_normalize_sf((SoftFloat){ONE_BITS-frac_bits, v});} /** * Rounding is to -inf. */static inline av_const int av_sf2int(SoftFloat v, int frac_bits){    v.exp += frac_bits - ONE_BITS;    if(v.exp >= 0) return v.mant <<  v.exp ;    else           return v.mant >>(-v.exp);} #endif /* AVUTIL_SOFTFLOAT_H */