interpreter/preprocessor/faust-0.9.47mr3/compiler/headers/interval.hh

   1 /************************************************************************
   2  ************************************************************************
   3     FAUST compiler
   4         Copyright (C) 2003-2004 GRAME, Centre National de Creation Musicale
   5     ---------------------------------------------------------------------
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  ************************************************************************
  20  ************************************************************************/
  21
  22
  23
  24 #ifndef __signals_intervals__
  25 #define __signals_intervals__
  26
  27 #include <math.h>
  28 #include <iostream>
  29
  30 #ifdef WIN32
  31 inline double log2(double e) { return log(e)/log(double(2)); }
  32 #endif
  33
  34 using namespace std;
  35
  36 struct interval
  37 {
  38         bool    valid;                  ///< true if it is a valid interval
  39         double  lo;                             ///< minimal value
  40         double  hi;                             ///< maximal value
  41
  42     interval ()                                         : valid(false), lo(-HUGE_VAL), hi(HUGE_VAL) {}
  43     interval (double n)                         : valid(true), lo(n), hi(n) {}
  44         interval (double n, double m)   : valid(true), lo(min(n,m)), hi(max(n,m)) {}
  45     interval (const interval& r)        : valid(r.valid), lo(r.lo), hi(r.hi) {}
  46
  47         bool isconst() { return valid & (lo == hi); }
  48 };
  49
  50 inline ostream& operator<<(ostream& dst, const interval& i)
  51 {
  52         if (i.valid) {
  53                 return  dst << "interval(" << i.lo << ", " << i.hi << ")";
  54         } else {
  55                 return  dst << "interval()";
  56         }
  57 }
  58
  59 inline double min(double x, double y) { return (x<y) ? x:y; }
  60 inline double max(double x, double y) { return (x>y) ? x:y; }
  61 inline double min4(double a, double b, double c, double d)      { return min(min(a,b),min(c,d)); }
  62 inline double max4(double a, double b, double c, double d)      { return max(max(a,b),max(c,d)); }
  63
  64 inline interval reunion(const interval& x, const interval& y)
  65 {
  66         if (x.valid & y.valid) {
  67                 return interval(min(x.lo,y.lo), max(x.hi,y.hi));
  68         } else {
  69                 return interval();
  70         }
  71 }
  72
  73
  74 inline interval operator+(const interval& x, const interval& y)
  75 {
  76         return (x.valid&y.valid) ? interval(x.lo+y.lo, x.hi+y.hi) : interval();
  77 }
  78
  79 inline interval operator-(const interval& x, const interval& y)
  80 {
  81         return (x.valid & y.valid) ? interval(x.lo-y.hi, x.hi-y.lo) : interval();;
  82 }
  83
  84 inline interval operator*(const interval& x, const interval& y)
  85 {
  86         if (x.valid&y.valid) {
  87                 double a=x.lo*y.lo;
  88                 double b=x.lo*y.hi;
  89                 double c=x.hi*y.lo;
  90                 double d=x.hi*y.hi;
  91                 return interval(min4(a,b,c,d), max4(a,b,c,d));
  92         } else {
  93                 return interval();
  94         }
  95 }
  96
  97 inline interval operator/(const interval& x, const interval& y)
  98 {
  99         return (x.valid && y.valid && (y.lo > 0 | y.hi < 0))
 100                         ? x * interval(1/y.hi,1/y.lo)
 101                         : interval();
 102 }
 103
 104 inline interval operator%(const interval& x, const interval& y)
 105 {
 106         return (x.valid && y.valid && x.lo >= 0 && y.lo > 0)
 107                         ? interval(0,y.hi)
 108                         : interval();
 109 }
 110
 111 /**
 112  * Convert a number 1bbb..b into a bit mask 1111..1 of same width
 113  */
 114 inline int bitmask (double x)   {
 115     int v = int(x);
 116     for (int i=1; i<32; i*=2)   { v |= v>>i; }
 117     return v;
 118 }
 119
 120 //----------------------booleans&bits--------------------------------------
 121
 122 inline interval operator&(const interval& x, const interval& y)
 123 {
 124         if (x.valid && y.valid) {
 125                 if (x.lo >= 0 & y.lo >= 0) {
 126                         return interval(0, bitmask(x.hi) & bitmask(y.hi));
 127                 } else if (y.lo >= 0) {
 128                         return interval(0, bitmask(y.hi));
 129                 } else if (x.lo >= 0) {
 130                         return interval(0, bitmask(y.hi));
 131                 } else {
 132                         return interval();
 133                 }
 134         } else if (x.valid & x.lo >= 0) {
 135                 return interval(0, bitmask(x.hi));
 136         } else if (y.valid & y.lo >= 0) {
 137                 return interval(0, bitmask(y.hi));
 138         } else {
 139                 return interval();
 140         }
 141 }
 142
 143 inline interval operator|(const interval& x, const interval& y)
 144 {
 145         if (x.valid && y.valid && x.lo >= 0 && y.lo >= 0) {
 146                 return interval(0, bitmask(x.hi) | bitmask(y.hi));
 147         } else {
 148                 return interval();
 149         }
 150 }
 151
 152 inline interval operator^(const interval&, const interval&)
 153 {
 154         return interval();
 155 }
 156
 157 inline interval operator<<(const interval&, const interval&)
 158 {
 159         return interval();
 160 }
 161
 162 inline interval operator>>(const interval&, const interval&)
 163 {
 164         return interval();
 165 }
 166
 167 // ---------------------comparaisons------------------------------
 168 // note : les comparaisons ne portent pas sur les intervals
 169 // mais l'interval des comparaisons de signaux
 170
 171 inline interval operator<(const interval&, const interval&)
 172 {
 173         return interval(0,1);
 174 }
 175
 176 inline interval operator<=(const interval&, const interval&)
 177 {
 178         return interval(0,1);
 179 }
 180
 181 inline interval operator>(const interval&, const interval&)
 182 {
 183         return interval(0,1);
 184 }
 185
 186 inline interval operator>=(const interval&, const interval&)
 187 {
 188         return interval(0,1);
 189 }
 190
 191 inline interval operator==(const interval&, const interval&)
 192 {
 193         return interval(0,1);
 194 }
 195
 196 inline interval operator!=(const interval&, const interval&)
 197 {
 198         return interval(0,1);
 199 }
 200
 201 //-----------------------------------------------------------------------
 202
 203 inline interval min(const interval& x, const interval& y)
 204 {
 205         return interval(min(x.lo,y.lo), min(x.hi,y.hi));
 206 }
 207
 208 inline interval max(const interval& x, const interval& y)
 209 {
 210         return interval(max(x.lo,y.lo), max(x.hi,y.hi));
 211 }
 212
 213 inline interval abs(const interval& x)
 214 {
 215         if (x.valid) {
 216                 if (x.lo >= 0) {
 217                         return x;
 218                 } else if (x.hi < 0) {
 219                         return interval(fabs(x.hi), fabs(x.lo));
 220                 } else {
 221                         return interval(0, max(fabs(x.lo), x.hi));
 222                 }
 223         } else {
 224                 return x;
 225         }
 226 }
 227
 228 #endif