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 tree double_int_to_tree (tree, double_int);
  65 bool double_int_fits_to_tree_p (const_tree, double_int);
  66
  67 /* Constructs double_int from tree CST.  */
  68
  69 #define tree_to_double_int(cst) (TREE_INT_CST (cst))
  70
  71 /* Constructs double_int from integer CST.  The bits over the precision of
  72    HOST_WIDE_INT are filled with the sign bit.  */
  73
  74 static inline double_int
  75 shwi_to_double_int (HOST_WIDE_INT cst)
  76 {
  77   double_int r;
  78
  79   r.low = (unsigned HOST_WIDE_INT) cst;
  80   r.high = cst < 0 ? -1 : 0;
  81
  82   return r;
  83 }
  84
  85 /* Some useful constants.  */
  86
  87 #define double_int_minus_one (shwi_to_double_int (-1))
  88 #define double_int_zero (shwi_to_double_int (0))
  89 #define double_int_one (shwi_to_double_int (1))
  90 #define double_int_two (shwi_to_double_int (2))
  91 #define double_int_ten (shwi_to_double_int (10))
  92
  93 /* Constructs double_int from unsigned integer CST.  The bits over the
  94    precision of HOST_WIDE_INT are filled with zeros.  */
  95
  96 static inline double_int
  97 uhwi_to_double_int (unsigned HOST_WIDE_INT cst)
  98 {
  99   double_int r;
 100
 101   r.low = cst;
 102   r.high = 0;
 103
 104   return r;
 105 }
 106
 107 /* The following operations perform arithmetics modulo 2^precision,
 108    so you do not need to call double_int_ext between them, even if
 109    you are representing numbers with precision less than
 110    2 * HOST_BITS_PER_WIDE_INT bits.  */
 111
 112 double_int double_int_mul (double_int, double_int);
 113 double_int double_int_add (double_int, double_int);
 114 double_int double_int_neg (double_int);
 115
 116 /* You must ensure that double_int_ext is called on the operands
 117    of the following operations, if the precision of the numbers
 118    is less than 2 * HOST_BITS_PER_WIDE_INT bits.  */
 119 bool double_int_fits_in_hwi_p (double_int, bool);
 120 bool double_int_fits_in_shwi_p (double_int);
 121 bool double_int_fits_in_uhwi_p (double_int);
 122 HOST_WIDE_INT double_int_to_shwi (double_int);
 123 unsigned HOST_WIDE_INT double_int_to_uhwi (double_int);
 124 double_int double_int_div (double_int, double_int, bool, unsigned);
 125 double_int double_int_sdiv (double_int, double_int, unsigned);
 126 double_int double_int_udiv (double_int, double_int, unsigned);
 127 double_int double_int_mod (double_int, double_int, bool, unsigned);
 128 double_int double_int_smod (double_int, double_int, unsigned);
 129 double_int double_int_umod (double_int, double_int, unsigned);
 130 double_int double_int_divmod (double_int, double_int, bool, unsigned, double_int *);
 131 double_int double_int_sdivmod (double_int, double_int, unsigned, double_int *);
 132 double_int double_int_udivmod (double_int, double_int, unsigned, double_int *);
 133 double_int double_int_setbit (double_int, unsigned);
 134
 135 /* Logical operations.  */
 136 static inline double_int
 137 double_int_not (double_int a)
 138 {
 139   a.low = ~a.low;
 140   a.high = ~ a.high;
 141   return a;
 142 }
 143
 144 /* Shift operations.  */
 145 double_int double_int_lshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 146 double_int double_int_rshift (double_int, HOST_WIDE_INT, unsigned int, bool);
 147
 148 /* Returns true if CST is negative.  Of course, CST is considered to
 149    be signed.  */
 150
 151 static inline bool
 152 double_int_negative_p (double_int cst)
 153 {
 154   return cst.high < 0;
 155 }
 156
 157 int double_int_cmp (double_int, double_int, bool);
 158 int double_int_scmp (double_int, double_int);
 159 int double_int_ucmp (double_int, double_int);
 160 void dump_double_int (FILE *, double_int, bool);
 161
 162 /* Zero and sign extension of numbers in smaller precisions.  */
 163
 164 double_int double_int_ext (double_int, unsigned, bool);
 165 double_int double_int_sext (double_int, unsigned);
 166 double_int double_int_zext (double_int, unsigned);
 167 double_int double_int_mask (unsigned);
 168
 169 #define ALL_ONES (~((unsigned HOST_WIDE_INT) 0))
 170
 171 /* The operands of the following comparison functions must be processed
 172    with double_int_ext, if their precision is less than
 173    2 * HOST_BITS_PER_WIDE_INT bits.  */
 174
 175 /* Returns true if CST is zero.  */
 176
 177 static inline bool
 178 double_int_zero_p (double_int cst)
 179 {
 180   return cst.low == 0 && cst.high == 0;
 181 }
 182
 183 /* Returns true if CST is one.  */
 184
 185 static inline bool
 186 double_int_one_p (double_int cst)
 187 {
 188   return cst.low == 1 && cst.high == 0;
 189 }
 190
 191 /* Returns true if CST is minus one.  */
 192
 193 static inline bool
 194 double_int_minus_one_p (double_int cst)
 195 {
 196   return (cst.low == ALL_ONES && cst.high == -1);
 197 }
 198
 199 /* Returns true if CST1 == CST2.  */
 200
 201 static inline bool
 202 double_int_equal_p (double_int cst1, double_int cst2)
 203 {
 204   return cst1.low == cst2.low && cst1.high == cst2.high;
 205 }
 206
 207
 208 /* Legacy interface with decomposed high/low parts.  */
 209
 210 extern tree force_fit_type_double (tree, unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 211                                    int, bool);
 212 extern int fit_double_type (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 213                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 214                             const_tree);
 215 extern int add_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 216                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 217                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 218                                  bool);
 219 #define add_double(l1,h1,l2,h2,lv,hv) \
 220   add_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 221 extern int neg_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 222                        unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 223 extern int mul_double_with_sign (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 224                                  unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 225                                  unsigned HOST_WIDE_INT *, HOST_WIDE_INT *,
 226                                  bool);
 227 #define mul_double(l1,h1,l2,h2,lv,hv) \
 228   mul_double_with_sign (l1, h1, l2, h2, lv, hv, false)
 229 extern void lshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 230                            HOST_WIDE_INT, unsigned int,
 231                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 232 extern void rshift_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 233                            HOST_WIDE_INT, unsigned int,
 234                            unsigned HOST_WIDE_INT *, HOST_WIDE_INT *, bool);
 235 extern void lrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 236                             HOST_WIDE_INT, unsigned int,
 237                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 238 extern void rrotate_double (unsigned HOST_WIDE_INT, HOST_WIDE_INT,
 239                             HOST_WIDE_INT, unsigned int,
 240                             unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
 241 extern int div_and_round_double (unsigned, int, unsigned HOST_WIDE_INT,
 242                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT,
 243                                  HOST_WIDE_INT, unsigned HOST_WIDE_INT *,
 244                                  HOST_WIDE_INT *, unsigned HOST_WIDE_INT *,
 245                                  HOST_WIDE_INT *);
 246
 247
 248 #ifndef GENERATOR_FILE
 249 /* Conversion to and from GMP integer representations.  */
 250
 251 void mpz_set_double_int (mpz_t, double_int, bool);
 252 double_int mpz_get_double_int (const_tree, mpz_t, bool);
 253 #endif
 254
 255 #endif /* DOUBLE_INT_H */