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 /* Shift operations.  */
 151 double_int double_int_lshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 152 double_int double_int_rshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 153
 154 /* Returns true if CST is negative.  Of course, CST is considered to
 155    be signed.  */
 156
 157 static inline bool
 158 double_int_negative_p (double_int cst)
 159 {
 160   return cst.high < 0;
 161 }
 162
 163 int double_int_cmp (double_int, double_int, bool);
 164 int double_int_scmp (double_int, double_int);
 165 int double_int_ucmp (double_int, double_int);
 166 void dump_double_int (FILE *, double_int, bool);
 167
 168 /* Zero and sign extension of numbers in smaller precisions.  */
 169
 170 double_int double_int_ext (double_int, unsigned, bool);
 171 double_int double_int_sext (double_int, unsigned);
 172 double_int double_int_zext (double_int, unsigned);
 173 double_int double_int_mask (unsigned);
 174
 175 #define ALL_ONES (~((unsigned HOST_WIDE_INT) 0))
 176
 177 /* The operands of the following comparison functions must be processed
 178    with double_int_ext, if their precision is less than
 179    2 * HOST_BITS_PER_WIDE_INT bits.  */
 180
 181 /* Returns true if CST is zero.  */
 182
 183 static inline bool
 184 double_int_zero_p (double_int cst)
 185 {
 186   return cst.low == 0 && cst.high == 0;
 187 }
 188
 189 /* Returns true if CST is one.  */
 190
 191 static inline bool
 192 double_int_one_p (double_int cst)
 193 {
 194   return cst.low == 1 && cst.high == 0;
 195 }
 196
 197 /* Returns true if CST is minus one.  */
 198
 199 static inline bool
 200 double_int_minus_one_p (double_int cst)
 201 {
 202   return (cst.low == ALL_ONES && cst.high == -1);
 203 }
 204
 205 /* Returns true if CST1 == CST2.  */
 206
 207 static inline bool
 208 double_int_equal_p (double_int cst1, double_int cst2)
 209 {
 210   return cst1.low == cst2.low && cst1.high == cst2.high;
 211 }
 212
 213
 214 /* Legacy interface with decomposed high/low parts.  */
 215
 216 extern tree force_fit_type_double (tree, unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 217                                    int, bool);
 218 extern int fit_double_type (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 219                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 220                             const_tree);
 221 extern int add_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 222                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 223                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 224                                  bool);
 225 #define add_double(l1,h1,l2,h2,lv,hv) \
 226   add_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 227 extern int neg_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 228                        unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 229 extern int mul_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 230                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 231                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 232                                  bool);
 233 #define mul_double(l1,h1,l2,h2,lv,hv) \
 234   mul_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 235 extern void lshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 236                            HOST_WIDE_INT, unsigned int,
 237                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 238 extern void rshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 239                            HOST_WIDE_INT, unsigned int,
 240                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 241 extern void lrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 242                             HOST_WIDE_INT, unsigned int,
 243                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 244 extern void rrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 245                             HOST_WIDE_INT, unsigned int,
 246                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 247 extern int div_and_round_double (unsigned, int, unsigned HOST_WIDE_INT,
 248                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT,
 249                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT *,
 250                                  HOST_WIDE_INT *, unsigned HOST_WIDE_INT *,
 251                                  HOST_WIDE_INT *);
 252
 253
 254 #ifndef GENERATOR_FILE
 255 /* Conversion to and from GMP integer representations.  */
 256
 257 void mpz_set_double_int (mpz_t, double_int, bool);
 258 double_int mpz_get_double_int (const_tree, mpz_t, bool);
 259 #endif
 260
 261 #endif /* DOUBLE_INT_H */