/* Copyright (C) 2005 Jean-Marc Valin *//**   @file pseudofloat.h   @brief Pseudo-floating point *//*   Redistribution and use in source and binary forms, with or without   modification, are permitted provided that the following conditions   are met:      - Redistributions of source code must retain the above copyright   notice, this list of conditions and the following disclaimer.      - 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.      - Neither the name of the Xiph.org Foundation nor the names of its   contributors may be used to endorse or promote products derived from   this software without specific prior written permission.      THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS   ``AS IS'' AND ANY EXPRESS 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 THE FOUNDATION OR   CONTRIBUTORS 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.*/#ifndef PSEUDOFLOAT_H#define PSEUDOFLOAT_H#include "misc.h"#include <math.h>#ifdef FIXED_POINTtypedef struct {   spx_int16_t m;   spx_int16_t e;} spx_float_t;#if 0#define FLOAT_ZERO ((spx_float_t){0,0})#define FLOAT_ONE ((spx_float_t){16384,-14})#define FLOAT_HALF ((spx_float_t){16384,-15})#else#define FLOAT_ZERO {0,0}#define FLOAT_ONE {16384,-14}#define FLOAT_HALF {16384,-15}#endif#define MIN(a,b) ((a)<(b)?(a):(b))static _inline spx_float_t PSEUDOFLOAT(spx_int32_t x){   int e=0;   int sign=0;   if (x<0)   {      sign = 1;      x = -x;   }   if (x==0) {	   spx_float_t tmp;	   tmp.e = 0;	   tmp.m = 0;	   return tmp;	/*      return (spx_float_t) {0,0};	*/   }   while (x>32767)   {      x >>= 1;      /*x *= .5;*/      e++;   }   while (x<16383)   {      x <<= 1;      /*x *= 2;*/      e--;   }#if 0   if (sign)      return (spx_float_t) {-x,e};   else            return (spx_float_t) {x,e};#else   {		spx_float_t tmp;		tmp.e = e;		if (sign) {			tmp.m = -x;		}		else {			tmp.m = x;		}		return tmp;   }#endif}static _inline spx_float_t FLOAT_ADD(spx_float_t a, spx_float_t b){   spx_float_t r;   if (a.m==0)      return b;   else if (b.m==0)      return a;#if 0   r = (a).e > (b).e ? (spx_float_t) {((a).m>>1) + ((b).m>>MIN(15,(a).e-(b).e+1)),(a).e+1} : (spx_float_t) {((b).m>>1) + ((a).m>>MIN(15,(b).e-(a).e+1)),(b).e+1};#else   {		spx_float_t tmp;	    if (a.e > b.e) {			tmp.m = (a.m>>1) + (b.m>>MIN(15, a.e-b.e+1));			tmp.e = a.e + 1;		}		else {			tmp.m = (b.m>>1) + (a.m>>MIN(15, b.e-a.e+1));			tmp.e = b.e+1;		}		r = tmp;   }#endif   if (r.m>0)   {      if (r.m<16384)      {         r.m<<=1;         r.e-=1;      }   } else {      if (r.m>-16384)      {         r.m<<=1;         r.e-=1;      }   }   /*printf ("%f + %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/   return r;}static _inline spx_float_t FLOAT_SUB(spx_float_t a, spx_float_t b){   spx_float_t r;   if (a.m==0)      return b;   else if (b.m==0)      return a;#if 0   r = (a).e > (b).e ? (spx_float_t) {((a).m>>1) - ((b).m>>MIN(15,(a).e-(b).e+1)),(a).e+1} : (spx_float_t) {((a).m>>MIN(15,(b).e-(a).e+1)) - ((b).m>>1) ,(b).e+1};#else   {		spx_float_t tmp;	    if (a.e > b.e) {			tmp.m = (a.m>>1) - (b.m>>MIN(15, a.e-b.e+1));			tmp.e = a.e + 1;		}		else {			tmp.m = (a.m>>MIN(15, b.e-a.e+1)) - (b.m>>1);			tmp.e = b.e+1;		}		r = tmp;   }#endif   if (r.m>0)   {      if (r.m<16384)      {         r.m<<=1;         r.e-=1;      }   } else {      if (r.m>-16384)      {         r.m<<=1;         r.e-=1;      }   }   /*printf ("%f + %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/   return r;}static _inline int FLOAT_LT(spx_float_t a, spx_float_t b){   if (a.m==0)      return b.m<0;   else if (b.m==0)      return a.m>0;      if ((a).e > (b).e)      return ((a).m>>1) < ((b).m>>MIN(15,(a).e-(b).e+1));   else       return ((b).m>>1) > ((a).m>>MIN(15,(b).e-(a).e+1));}static _inline int FLOAT_GT(spx_float_t a, spx_float_t b){   return FLOAT_LT(b,a);}static _inline spx_float_t FLOAT_MULT(spx_float_t a, spx_float_t b){#if 0   spx_float_t r = (spx_float_t) {(spx_int16_t)((spx_int32_t)(a).m*(b).m>>15), (a).e+(b).e+15};#else   spx_float_t r;   {		spx_float_t tmp;		tmp.m = (spx_int16_t)((spx_int32_t)(a).m*(b).m>>15);		tmp.e = (a).e+(b).e+15;		r = tmp;   }#endif   if (r.m>0)   {      if (r.m<16384)      {         r.m<<=1;         r.e-=1;      }   } else {      if (r.m>-16384)      {         r.m<<=1;         r.e-=1;      }   }   /*printf ("%f * %f = %f\n", REALFLOAT(a), REALFLOAT(b), REALFLOAT(r));*/   return r;   }static _inline spx_float_t FLOAT_SHL(spx_float_t a, int b){#if 0	return (spx_float_t) {a.m,a.e+b};#else	{		spx_float_t tmp;		tmp.m = a.m;		tmp.e = a.e + b;		return tmp;	}#endif}static _inline spx_int16_t FLOAT_EXTRACT16(spx_float_t a){   if (a.e<0)      return (a.m+(1<<(-a.e-1)))>>-a.e;   else      return a.m<<a.e;}static _inline spx_int32_t FLOAT_MUL32(spx_float_t a, spx_word32_t b){   if (a.e<-15)      return SHR32(MULT16_32_Q15(a.m, b),-a.e-15);   else      return SHL32(MULT16_32_Q15(a.m, b),15+a.e);}static _inline spx_float_t FLOAT_MUL32U(spx_word32_t a, spx_word32_t b){   int e=0;   /* FIXME: Handle the sign */   if (a==0) {#if 0      return (spx_float_t) {0,0};#else		spx_float_t tmp;		tmp.m = 0;		tmp.e = 0;		return tmp;#endif   }   while (a>32767)   {      a >>= 1;      e++;   }   while (a<16384)   {      a <<= 1;      e--;   }   while (b>32767)   {      b >>= 1;      e++;   }   while (b<16384)   {      b <<= 1;      e--;   }#if 0   return (spx_float_t) {MULT16_16_Q15(a,b),e+15};#else   {	spx_float_t tmp;	tmp.m = MULT16_16_Q15(a, b);	tmp.e = e+15;	return tmp;   }#endif}static _inline spx_float_t FLOAT_DIV32_FLOAT(spx_word32_t a, spx_float_t b){   int e=0;   /* FIXME: Handle the sign */   if (a==0) {#if 0      return (spx_float_t) {0,0};#else		spx_float_t tmp;		tmp.m = 0;		tmp.e = 0;		return tmp;#endif	}   while (a<SHL32(b.m,14))   {      a <<= 1;      e--;   }   while (a>=SHL32(b.m-1,15))   {      a >>= 1;      e++;   }#if 0   return (spx_float_t) {DIV32_16(a,b.m),e-b.e};#else   {	spx_float_t tmp;	tmp.m = DIV32_16(a,b.m);	tmp.e = e-b.e;	return tmp;   }#endif}static _inline spx_float_t FLOAT_DIV32(spx_word32_t a, spx_word32_t b){   int e=0;   /* FIXME: Handle the sign */   if (a==0){#if 0      return (spx_float_t) {0,0};#else		spx_float_t tmp;		tmp.m = 0;		tmp.e = 0;		return tmp;#endif	}   while (b>32767)   {      b >>= 1;      e--;   }   while (a<SHL32(b,14))   {      a <<= 1;      e--;   }   while (a>=SHL32(b-1,15))   {      a >>= 1;      e++;   }#if 0   return (spx_float_t) {DIV32_16(a,b),e};#else   {	   spx_float_t tmp = {DIV32_16(a,b),e};	   return tmp;   }#endif}static _inline spx_float_t FLOAT_DIVU(spx_float_t a, spx_float_t b){   int e=0;   spx_int32_t num;   num = a.m;   while (a.m >= b.m)   {      e++;      a.m >>= 1;   }   num = num << (15-e);#if 0   return (spx_float_t) {DIV32_16(num,b.m),a.e-b.e-15+e};#else   {	spx_float_t tmp;	tmp.m = DIV32_16(num, b.m);	tmp.e = a.e-b.e-15+e;	return tmp;  }#endif}#else#define spx_float_t float#define FLOAT_ZERO 0.f#define FLOAT_ONE 1.f#define FLOAT_HALF 0.5f#define PSEUDOFLOAT(x) (x)#define FLOAT_MULT(a,b) ((a)*(b))#define FLOAT_MUL32(a,b) ((a)*(b))#define FLOAT_DIV32(a,b) ((a)/(b))#define FLOAT_EXTRACT16(a) (a)#define FLOAT_ADD(a,b) ((a)+(b))#define FLOAT_SUB(a,b) ((a)-(b))#define REALFLOAT(x) (x)#define FLOAT_DIV32_FLOAT(a,b) ((a)/(b))#define FLOAT_MUL32U(a,b) ((a)*(b))#define FLOAT_SHL(a,b) (a)#define FLOAT_LT(a,b) ((a)<(b))#define FLOAT_GT(a,b) ((a)>(b))#define FLOAT_DIVU(a,b) ((a)/(b))#endif#endif