gcc/double-int.h

   1 /* Operations with long integers.
   2    Copyright (C) 2006, 2007, 2008, 2010 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it
   7 under the terms of the GNU General Public License as published by the
   8 Free Software Foundation; either version 3, or (at your option) any
   9 later version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT
  12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef DOUBLE_INT_H
  21 #define DOUBLE_INT_H
  22
  23 #ifndef GENERATOR_FILE
  24 #include <gmp.h>
  25 #endif
  26 #include "coretypes.h"
  27
  28 /* A large integer is currently represented as a pair of HOST_WIDE_INTs.
  29    It therefore represents a number with precision of
  30    2 * HOST_BITS_PER_WIDE_INT bits (it is however possible that the
  31    internal representation will change, if numbers with greater precision
  32    are needed, so the users should not rely on it).  The representation does
  33    not contain any information about signedness of the represented value, so
  34    it can be used to represent both signed and unsigned numbers.  For
  35    operations where the results depend on signedness (division, comparisons),
  36    it must be specified separately.  For each such operation, there are three
  37    versions of the function -- double_int_op, that takes an extra UNS argument
  38    giving the signedness of the values, and double_int_sop and double_int_uop
  39    that stand for its specializations for signed and unsigned values.
  40
  41    You may also represent with numbers in smaller precision using double_int.
  42    You however need to use double_int_ext (that fills in the bits of the
  43    number over the prescribed precision with zeros or with the sign bit) before
  44    operations that do not perform arithmetics modulo 2^precision (comparisons,
  45    division), and possibly before storing the results, if you want to keep
  46    them in some canonical form).  In general, the signedness of double_int_ext
  47    should match the signedness of the operation.
  48
  49    ??? The components of double_int differ in signedness mostly for
  50    historical reasons (they replace an older structure used to represent
  51    numbers with precision higher than HOST_WIDE_INT).  It might be less
  52    confusing to have them both signed or both unsigned.  */
  53
  54 typedef struct
  55 {
  56   unsigned HOST_WIDE_INT low;
  57   HOST_WIDE_INT high;
  58 } double_int;
  59
  60 #define HOST_BITS_PER_DOUBLE_INT (2 * HOST_BITS_PER_WIDE_INT)
  61
  62 /* Constructors and conversions.  */
  63
  64 /* Constructs double_int from integer CST.  The bits over the precision of
  65    HOST_WIDE_INT are filled with the sign bit.  */
  66
  67 static inline double_int
  68 shwi_to_double_int (HOST_WIDE_INT cst)
  69 {
  70   double_int r;
  71
  72   r.low = (unsigned HOST_WIDE_INT) cst;
  73   r.high = cst < 0 ? -1 : 0;
  74
  75   return r;
  76 }
  77
  78 /* Some useful constants.  */
  79
  80 #define double_int_minus_one (shwi_to_double_int (-1))
  81 #define double_int_zero (shwi_to_double_int (0))
  82 #define double_int_one (shwi_to_double_int (1))
  83 #define double_int_two (shwi_to_double_int (2))
  84 #define double_int_ten (shwi_to_double_int (10))
  85
  86 /* Constructs double_int from unsigned integer CST.  The bits over the
  87    precision of HOST_WIDE_INT are filled with zeros.  */
  88
  89 static inline double_int
  90 uhwi_to_double_int (unsigned HOST_WIDE_INT cst)
  91 {
  92   double_int r;
  93
  94   r.low = cst;
  95   r.high = 0;
  96
  97   return r;
  98 }
  99
 100 /* Returns value of CST as a signed number.  CST must satisfy
 101    double_int_fits_in_shwi_p.  */
 102
 103 static inline HOST_WIDE_INT
 104 double_int_to_shwi (double_int cst)
 105 {
 106   return (HOST_WIDE_INT) cst.low;
 107 }
 108
 109 /* Returns value of CST as an unsigned number.  CST must satisfy
 110    double_int_fits_in_uhwi_p.  */
 111
 112 static inline unsigned HOST_WIDE_INT
 113 double_int_to_uhwi (double_int cst)
 114 {
 115   return cst.low;
 116 }
 117
 118 bool double_int_fits_in_hwi_p (double_int, bool);
 119 bool double_int_fits_in_shwi_p (double_int);
 120
 121 /* Returns true if CST fits in unsigned HOST_WIDE_INT.  */
 122
 123 static inline bool
 124 double_int_fits_in_uhwi_p (double_int cst)
 125 {
 126   return cst.high == 0;
 127 }
 128
 129 /* The following operations perform arithmetics modulo 2^precision,
 130    so you do not need to call double_int_ext between them, even if
 131    you are representing numbers with precision less than
 132    2 * HOST_BITS_PER_WIDE_INT bits.  */
 133
 134 double_int double_int_mul (double_int, double_int);
 135 double_int double_int_add (double_int, double_int);
 136 double_int double_int_sub (double_int, double_int);
 137 double_int double_int_neg (double_int);
 138
 139 /* You must ensure that double_int_ext is called on the operands
 140    of the following operations, if the precision of the numbers
 141    is less than 2 * HOST_BITS_PER_WIDE_INT bits.  */
 142 double_int double_int_div (double_int, double_int, bool, unsigned);
 143 double_int double_int_sdiv (double_int, double_int, unsigned);
 144 double_int double_int_udiv (double_int, double_int, unsigned);
 145 double_int double_int_mod (double_int, double_int, bool, unsigned);
 146 double_int double_int_smod (double_int, double_int, unsigned);
 147 double_int double_int_umod (double_int, double_int, unsigned);
 148 double_int double_int_divmod (double_int, double_int, bool, unsigned, double_int *);
 149 double_int double_int_sdivmod (double_int, double_int, unsigned, double_int *);
 150 double_int double_int_udivmod (double_int, double_int, unsigned, double_int *);
 151 double_int double_int_setbit (double_int, unsigned);
 152
 153 /* Logical operations.  */
 154
 155 /* Returns ~A.  */
 156
 157 static inline double_int
 158 double_int_not (double_int a)
 159 {
 160   a.low = ~a.low;
 161   a.high = ~ a.high;
 162   return a;
 163 }
 164
 165 /* Returns A | B.  */
 166
 167 static inline double_int
 168 double_int_ior (double_int a, double_int b)
 169 {
 170   a.low |= b.low;
 171   a.high |= b.high;
 172   return a;
 173 }
 174
 175 /* Returns A & B.  */
 176
 177 static inline double_int
 178 double_int_and (double_int a, double_int b)
 179 {
 180   a.low &= b.low;
 181   a.high &= b.high;
 182   return a;
 183 }
 184
 185 /* Returns A ^ B.  */
 186
 187 static inline double_int
 188 double_int_xor (double_int a, double_int b)
 189 {
 190   a.low ^= b.low;
 191   a.high ^= b.high;
 192   return a;
 193 }
 194
 195
 196 /* Shift operations.  */
 197 double_int double_int_lshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 198 double_int double_int_rshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 199 double_int double_int_lrotate (double_int, HOST_WIDE_INT, unsigned int);
 200 double_int double_int_rrotate (double_int, HOST_WIDE_INT, unsigned int);
 201
 202 /* Returns true if CST is negative.  Of course, CST is considered to
 203    be signed.  */
 204
 205 static inline bool
 206 double_int_negative_p (double_int cst)
 207 {
 208   return cst.high < 0;
 209 }
 210
 211 int double_int_cmp (double_int, double_int, bool);
 212 int double_int_scmp (double_int, double_int);
 213 int double_int_ucmp (double_int, double_int);
 214
 215 double_int double_int_max (double_int, double_int, bool);
 216 double_int double_int_smax (double_int, double_int);
 217 double_int double_int_umax (double_int, double_int);
 218
 219 double_int double_int_min (double_int, double_int, bool);
 220 double_int double_int_smin (double_int, double_int);
 221 double_int double_int_umin (double_int, double_int);
 222
 223 void dump_double_int (FILE *, double_int, bool);
 224
 225 /* Zero and sign extension of numbers in smaller precisions.  */
 226
 227 double_int double_int_ext (double_int, unsigned, bool);
 228 double_int double_int_sext (double_int, unsigned);
 229 double_int double_int_zext (double_int, unsigned);
 230 double_int double_int_mask (unsigned);
 231
 232 #define ALL_ONES (~((unsigned HOST_WIDE_INT) 0))
 233
 234 /* The operands of the following comparison functions must be processed
 235    with double_int_ext, if their precision is less than
 236    2 * HOST_BITS_PER_WIDE_INT bits.  */
 237
 238 /* Returns true if CST is zero.  */
 239
 240 static inline bool
 241 double_int_zero_p (double_int cst)
 242 {
 243   return cst.low == 0 && cst.high == 0;
 244 }
 245
 246 /* Returns true if CST is one.  */
 247
 248 static inline bool
 249 double_int_one_p (double_int cst)
 250 {
 251   return cst.low == 1 && cst.high == 0;
 252 }
 253
 254 /* Returns true if CST is minus one.  */
 255
 256 static inline bool
 257 double_int_minus_one_p (double_int cst)
 258 {
 259   return (cst.low == ALL_ONES && cst.high == -1);
 260 }
 261
 262 /* Returns true if CST1 == CST2.  */
 263
 264 static inline bool
 265 double_int_equal_p (double_int cst1, double_int cst2)
 266 {
 267   return cst1.low == cst2.low && cst1.high == cst2.high;
 268 }
 269
 270
 271 /* Legacy interface with decomposed high/low parts.  */
 272
 273 extern int add_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 274                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 275                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 276                                  bool);
 277 #define add_double(l1,h1,l2,h2,lv,hv) \
 278   add_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 279 extern int neg_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 280                        unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 281 extern int mul_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 282                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 283                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 284                                  bool);
 285 #define mul_double(l1,h1,l2,h2,lv,hv) \
 286   mul_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 287 extern void lshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 288                            HOST_WIDE_INT, unsigned int,
 289                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 290 extern void rshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 291                            HOST_WIDE_INT, unsigned int,
 292                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 293 extern int div_and_round_double (unsigned, int, unsigned HOST_WIDE_INT,
 294                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT,
 295                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT *,
 296                                  HOST_WIDE_INT *, unsigned HOST_WIDE_INT *,
 297                                  HOST_WIDE_INT *);
 298
 299
 300 #ifndef GENERATOR_FILE
 301 /* Conversion to and from GMP integer representations.  */
 302
 303 void mpz_set_double_int (mpz_t, double_int, bool);
 304 double_int mpz_get_double_int (const_tree, mpz_t, bool);
 305 #endif
 306
 307 #endif /* DOUBLE_INT_H */