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 /* The following operations perform arithmetics modulo 2^precision,
 101    so you do not need to call double_int_ext between them, even if
 102    you are representing numbers with precision less than
 103    2 * HOST_BITS_PER_WIDE_INT bits.  */
 104
 105 double_int double_int_mul (double_int, double_int);
 106 double_int double_int_add (double_int, double_int);
 107 double_int double_int_neg (double_int);
 108
 109 /* You must ensure that double_int_ext is called on the operands
 110    of the following operations, if the precision of the numbers
 111    is less than 2 * HOST_BITS_PER_WIDE_INT bits.  */
 112 bool double_int_fits_in_hwi_p (double_int, bool);
 113 bool double_int_fits_in_shwi_p (double_int);
 114 bool double_int_fits_in_uhwi_p (double_int);
 115 HOST_WIDE_INT double_int_to_shwi (double_int);
 116 unsigned HOST_WIDE_INT double_int_to_uhwi (double_int);
 117 double_int double_int_div (double_int, double_int, bool, unsigned);
 118 double_int double_int_sdiv (double_int, double_int, unsigned);
 119 double_int double_int_udiv (double_int, double_int, unsigned);
 120 double_int double_int_mod (double_int, double_int, bool, unsigned);
 121 double_int double_int_smod (double_int, double_int, unsigned);
 122 double_int double_int_umod (double_int, double_int, unsigned);
 123 double_int double_int_divmod (double_int, double_int, bool, unsigned, double_int *);
 124 double_int double_int_sdivmod (double_int, double_int, unsigned, double_int *);
 125 double_int double_int_udivmod (double_int, double_int, unsigned, double_int *);
 126 double_int double_int_setbit (double_int, unsigned);
 127
 128 /* Logical operations.  */
 129
 130 /* Returns ~A.  */
 131
 132 static inline double_int
 133 double_int_not (double_int a)
 134 {
 135   a.low = ~a.low;
 136   a.high = ~ a.high;
 137   return a;
 138 }
 139
 140 /* Returns A | B.  */
 141
 142 static inline double_int
 143 double_int_ior (double_int a, double_int b)
 144 {
 145   a.low |= b.low;
 146   a.high |= b.high;
 147   return a;
 148 }
 149
 150 /* Returns A & B.  */
 151
 152 static inline double_int
 153 double_int_and (double_int a, double_int b)
 154 {
 155   a.low &= b.low;
 156   a.high &= b.high;
 157   return a;
 158 }
 159
 160 /* Shift operations.  */
 161 double_int double_int_lshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 162 double_int double_int_rshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 163
 164 /* Returns true if CST is negative.  Of course, CST is considered to
 165    be signed.  */
 166
 167 static inline bool
 168 double_int_negative_p (double_int cst)
 169 {
 170   return cst.high < 0;
 171 }
 172
 173 int double_int_cmp (double_int, double_int, bool);
 174 int double_int_scmp (double_int, double_int);
 175 int double_int_ucmp (double_int, double_int);
 176 void dump_double_int (FILE *, double_int, bool);
 177
 178 /* Zero and sign extension of numbers in smaller precisions.  */
 179
 180 double_int double_int_ext (double_int, unsigned, bool);
 181 double_int double_int_sext (double_int, unsigned);
 182 double_int double_int_zext (double_int, unsigned);
 183 double_int double_int_mask (unsigned);
 184
 185 #define ALL_ONES (~((unsigned HOST_WIDE_INT) 0))
 186
 187 /* The operands of the following comparison functions must be processed
 188    with double_int_ext, if their precision is less than
 189    2 * HOST_BITS_PER_WIDE_INT bits.  */
 190
 191 /* Returns true if CST is zero.  */
 192
 193 static inline bool
 194 double_int_zero_p (double_int cst)
 195 {
 196   return cst.low == 0 && cst.high == 0;
 197 }
 198
 199 /* Returns true if CST is one.  */
 200
 201 static inline bool
 202 double_int_one_p (double_int cst)
 203 {
 204   return cst.low == 1 && cst.high == 0;
 205 }
 206
 207 /* Returns true if CST is minus one.  */
 208
 209 static inline bool
 210 double_int_minus_one_p (double_int cst)
 211 {
 212   return (cst.low == ALL_ONES && cst.high == -1);
 213 }
 214
 215 /* Returns true if CST1 == CST2.  */
 216
 217 static inline bool
 218 double_int_equal_p (double_int cst1, double_int cst2)
 219 {
 220   return cst1.low == cst2.low && cst1.high == cst2.high;
 221 }
 222
 223
 224 /* Legacy interface with decomposed high/low parts.  */
 225
 226 extern tree force_fit_type_double (tree, unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 227                                    int, bool);
 228 extern int fit_double_type (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 229                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 230                             const_tree);
 231 extern int add_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 232                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 233                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 234                                  bool);
 235 #define add_double(l1,h1,l2,h2,lv,hv) \
 236   add_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 237 extern int neg_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 238                        unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 239 extern int mul_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 240                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 241                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 242                                  bool);
 243 #define mul_double(l1,h1,l2,h2,lv,hv) \
 244   mul_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 245 extern void lshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 246                            HOST_WIDE_INT, unsigned int,
 247                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 248 extern void rshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 249                            HOST_WIDE_INT, unsigned int,
 250                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 251 extern void lrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 252                             HOST_WIDE_INT, unsigned int,
 253                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 254 extern void rrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 255                             HOST_WIDE_INT, unsigned int,
 256                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 257 extern int div_and_round_double (unsigned, int, unsigned HOST_WIDE_INT,
 258                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT,
 259                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT *,
 260                                  HOST_WIDE_INT *, unsigned HOST_WIDE_INT *,
 261                                  HOST_WIDE_INT *);
 262
 263
 264 #ifndef GENERATOR_FILE
 265 /* Conversion to and from GMP integer representations.  */
 266
 267 void mpz_set_double_int (mpz_t, double_int, bool);
 268 double_int mpz_get_double_int (const_tree, mpz_t, bool);
 269 #endif
 270
 271 #endif /* DOUBLE_INT_H */