/usr/include/givaro/montgomery-int32.inl is in libgivaro-dev 4.0.2-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 | // ==========================================================================
// $Id: givmontg32.inl,v 1.14 2011-02-04 14:11:46 jgdumas Exp $
// Copyright(c)'1994-2009 by The Givaro group
// This file is part of Givaro.
// Givaro is governed by the CeCILL-B license under French law
// and abiding by the rules of distribution of free software.
// see the COPYRIGHT file for more details.
// ==========================================================================
#ifndef __GIVARO_mong32_INL
#define __GIVARO_mong32_INL
namespace Givaro {
inline Montgomery<int32_t>::Element Montgomery<int32_t>::redcal(const Element c) const
{
Element c0 = (Element)(c & MASK32); /* c mod B */
c0 = (Element)((c0 * _nim) & MASK32); /* -c/p mod B */
// c0 *= _p;
// c0 += c; /* c = 0 mod B */
c0 = c + c0*_p;
c0 >>= HALF_BITS32;
return (c0>=_p?c0-=_p:c0);
}
inline Montgomery<int32_t>::Element Montgomery<int32_t>::redcsal(const Element c) const
{
Element c0 = (Element)((c * _nim) & MASK32); /* -c/p mod B */
c0 = c + c0 * _p; /* c = 0 mod B */
c0 >>= HALF_BITS32;
return (c0>=_p?c0-=_p:c0);
}
inline Montgomery<int32_t>::Element& Montgomery<int32_t>::redc(Element& r, const Element c) const
{
r = (Element)(c & MASK32); /* c mod B */
r *= _nim;
r &= MASK32;
r *= _p;
r += c;
r >>= HALF_BITS32;
return (r>=_p?r-=_p:r);
}
inline Montgomery<int32_t>::Element& Montgomery<int32_t>::redcs(Element& r, const Element c) const
{
r = (Element)((c * _nim) & MASK32); /* -c/p mod B */
r = c + r * _p; /* c = 0 mod B */
r >>= HALF_BITS32;
return (r>=_p?r-=_p:r);
}
inline Montgomery<int32_t>::Element& Montgomery<int32_t>::redcin(Element& r) const
{
Element c0 = (Element)(r & MASK32); /* c mod B */
c0 = (Element)((c0 * _nim) & MASK32); /* -c/p mod B */
r += c0 * _p; /* c = 0 mod B */
r >>= HALF_BITS32;
return (r>=_p?r-=_p:r);
}
inline Montgomery<int32_t>::Element& Montgomery<int32_t>::redcsin(Element& r) const
{
Element c0 = (Element)((r * _nim) & MASK32); /* -c/p mod B */
r += c0 * _p; /* c = 0 mod B */
r >>= HALF_BITS32;
return (r>=_p?r-=_p:r);
}
} // namespace Givaro
// r = a*b
#define __GIVARO_MONTG32_MUL(r,p,a,b) (redc(r,a*b))
// r *= a
#define __GIVARO_MONTG32_MULIN(r,p,a) (redcin(r*=a))
// r = a - b
#define __GIVARO_MONTG32_SUB(r,p,a,b) ( r = (a>=b)? a-b: (p-b)+a )
// r -= a
//#define __GIVARO_MONTG32_SUBIN(r,p,a) { r -= a; r= (r < 0 ? r+p : r); }
#define __GIVARO_MONTG32_SUBIN(r,p,a) { if (r<a) r+=(p-a); else r-=a; }
// r = a+b
#define __GIVARO_MONTG32_ADD(r,p,a,b) { r = (a+b); r= (r < p ? r : r-p); }
// r += a
#define __GIVARO_MONTG32_ADDIN(r,p,a) { r += a; r= (r < p ? r : r-p); }
// r <- a*b+c % p
//#define __GIVARO_MONTG32_MULADD(r,p,a,b,c) { redc(r,a*b) += c; r= (r < p ? r : r-p); }
#define __GIVARO_MONTG32_MULADD(r,p,a,b,c) { r = redcal(a*b) + c; r= (r < p ? r : r-p); }
#define __GIVARO_MONTG32_MULADDIN(r,p,a,b) { r+=redcal(a*b); r= (r < p ? r : r-p); }
#define __GIVARO_MONTG32_NEG(r,p,a) (r = (a == 0 ? 0 : p-a))
#define __GIVARO_MONTG32_NEGIN(r,p) (r = (r == 0 ? 0 : p-r))
namespace Givaro {
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::mul (Element& r, const Element& a, const Element& b) const
{
return __GIVARO_MONTG32_MUL(r,_p,a,b);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::sub (Element& r, const Element& a, const Element& b) const
{
return __GIVARO_MONTG32_SUB(r,_p,a,b);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::add (Element& r, const Element& a, const Element& b) const
{
__GIVARO_MONTG32_ADD(r,_p,a,b);
return r;
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::neg (Element& r, const Element& a) const
{
return __GIVARO_MONTG32_NEG(r,_p,a);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::inv (Element& r, const Element& a) const
{
// invext(aB) --> 1/a*1/B
// % * B^3 --> B²/a
// redc --> B/a
int32_t t;
invext(t, int32_t(a), int32_t(_p));
if (t < 0) t += _p;
return redc(r, uint32_t(t) * _B3p) ;
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::div (Element& r, const Element& a, const Element& b) const
{
return mulin( inv(r,b), a );
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::mulin (Element& r, const Element& a) const
{
return __GIVARO_MONTG32_MULIN(r,_p, a);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::divin (Element& r, const Element& a) const
{
Montgomery<int32_t>::Element ia;
inv(ia, a);
return mulin(r, ia);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::addin (Element& r, const Element& a) const
{
__GIVARO_MONTG32_ADDIN(r,_p, a);
return r;
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::subin (Element& r, const Element& a) const
{
__GIVARO_MONTG32_SUBIN(r,_p, a);
return r;
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::negin (Element& r) const
{
return __GIVARO_MONTG32_NEGIN(r,_p);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::invin (Element& r) const
{
Element t;
return r = inv(t,r);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::axpy(Element& r, const Element& a, const Element& b, const Element& c) const
{
__GIVARO_MONTG32_MULADD(r, _p, a, b, c);
return r;
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::axpyin(Element& r, const Element& a, const Element& b) const
{
__GIVARO_MONTG32_MULADDIN(r, _p, a, b);
return r;
}
// r <- a*b-c
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::axmy(Element& r, const Element& a, const Element& b, const Element& c) const
{
return this->subin(this->mul(r,a,b), c);
}
// r = c - a*b
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::maxpy(Element& r, const Element& a, const Element& b, const Element& c) const
{
Element t;
return this->sub(r, c, this->mul(t,a,b));
}
// r -= a*b
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::maxpyin(Element& r, const Element& a, const Element& b) const
{
Element t;
return this->subin(r, this->mul(t,a,b));
}
// r = a*b - r
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::axmyin(Element& r, const Element& a, const Element& b) const
{
maxpyin(r,a,b);
return negin(r);
}
// --------------------
// ----- Initialisation
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::init (Element& r, const double a) const
{
r = static_cast<Element>(std::fmod((a < 0.0)? -a : a, double(_p)));
if (a < 0.0) negin(r);
return redc(r, r * _B2p);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::init (Element& r, const int64_t a) const
{
r = static_cast<Element>(std::abs(a) % int64_t(_p));
if (a < 0) negin(r);
return redc(r, r * _B2p);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::init (Element& r, const uint64_t a) const
{
r = static_cast<Element>(a % uint64_t(_p));
return redc(r, r * _B2p);
}
inline Montgomery<int32_t>::Element&
Montgomery<int32_t>::init (Element& r, const Integer& a) const
{
r = static_cast<Element>(((a < 0)? -a : a) % _p);
if (a < 0) negin(r);
return redc(r, r * _B2p);
}
//----- IO
inline std::ostream&
Montgomery<int32_t>::write (std::ostream& s) const
{
return s << "Montgomery<int32_t> modulo " << residu();
}
inline std::istream&
Montgomery<int32_t>::read (std::istream& s, Element& a) const
{
Integer tmp;
s >> tmp;
init(a, tmp);
return s;
}
inline std::ostream&
Montgomery<int32_t>::write (std::ostream& s, const Element& a) const
{
// Element tmp;
// return s << redcs(tmp,a);
Element tmp;
redcs(tmp,a);
return s << tmp;
}
} // namespace Givaro
#endif // __GIVARO_mong32_INL
|