1 /* Operations with long integers. 2 Copyright (C) 2006, 2007, 2008 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 union tree_node; 61 62 /* Constructors and conversions. */ 63 64 union tree_node *double_int_to_tree (union tree_node *, double_int); 65 bool double_int_fits_to_tree_p (const union tree_node *, double_int); 66 double_int tree_to_double_int (const union tree_node *); 67 68 /* Constructs double_int from integer CST. The bits over the precision of 69 HOST_WIDE_INT are filled with the sign bit. */ 70 71 static inline double_int 72 shwi_to_double_int (HOST_WIDE_INT cst) 73 { 74 double_int r; 75 76 r.low = (unsigned HOST_WIDE_INT) cst; 77 r.high = cst < 0 ? -1 : 0; 78 79 return r; 80 } 81 82 /* Some useful constants. */ 83 84 #define double_int_minus_one (shwi_to_double_int (-1)) 85 #define double_int_zero (shwi_to_double_int (0)) 86 #define double_int_one (shwi_to_double_int (1)) 87 #define double_int_two (shwi_to_double_int (2)) 88 #define double_int_ten (shwi_to_double_int (10)) 89 90 /* Constructs double_int from unsigned integer CST. The bits over the 91 precision of HOST_WIDE_INT are filled with zeros. */ 92 93 static inline double_int 94 uhwi_to_double_int (unsigned HOST_WIDE_INT cst) 95 { 96 double_int r; 97 98 r.low = cst; 99 r.high = 0; 100 101 return r; 102 } 103 104 /* The following operations perform arithmetics modulo 2^precision, 105 so you do not need to call double_int_ext between them, even if 106 you are representing numbers with precision less than 107 2 * HOST_BITS_PER_WIDE_INT bits. */ 108 109 double_int double_int_mul (double_int, double_int); 110 double_int double_int_add (double_int, double_int); 111 double_int double_int_neg (double_int); 112 113 /* You must ensure that double_int_ext is called on the operands 114 of the following operations, if the precision of the numbers 115 is less than 2 * HOST_BITS_PER_WIDE_INT bits. */ 116 bool double_int_fits_in_hwi_p (double_int, bool); 117 bool double_int_fits_in_shwi_p (double_int); 118 bool double_int_fits_in_uhwi_p (double_int); 119 HOST_WIDE_INT double_int_to_shwi (double_int); 120 unsigned HOST_WIDE_INT double_int_to_uhwi (double_int); 121 double_int double_int_div (double_int, double_int, bool, unsigned); 122 double_int double_int_sdiv (double_int, double_int, unsigned); 123 double_int double_int_udiv (double_int, double_int, unsigned); 124 double_int double_int_mod (double_int, double_int, bool, unsigned); 125 double_int double_int_smod (double_int, double_int, unsigned); 126 double_int double_int_umod (double_int, double_int, unsigned); 127 double_int double_int_divmod (double_int, double_int, bool, unsigned, double_int *); 128 double_int double_int_sdivmod (double_int, double_int, unsigned, double_int *); 129 double_int double_int_udivmod (double_int, double_int, unsigned, double_int *); 130 bool double_int_negative_p (double_int); 131 int double_int_cmp (double_int, double_int, bool); 132 int double_int_scmp (double_int, double_int); 133 int double_int_ucmp (double_int, double_int); 134 void dump_double_int (FILE *, double_int, bool); 135 136 /* Zero and sign extension of numbers in smaller precisions. */ 137 138 double_int double_int_ext (double_int, unsigned, bool); 139 double_int double_int_sext (double_int, unsigned); 140 double_int double_int_zext (double_int, unsigned); 141 double_int double_int_mask (unsigned); 142 143 #define ALL_ONES (~((unsigned HOST_WIDE_INT) 0)) 144 145 /* The operands of the following comparison functions must be processed 146 with double_int_ext, if their precision is less than 147 2 * HOST_BITS_PER_WIDE_INT bits. */ 148 149 /* Returns true if CST is zero. */ 150 151 static inline bool 152 double_int_zero_p (double_int cst) 153 { 154 return cst.low == 0 && cst.high == 0; 155 } 156 157 /* Returns true if CST is one. */ 158 159 static inline bool 160 double_int_one_p (double_int cst) 161 { 162 return cst.low == 1 && cst.high == 0; 163 } 164 165 /* Returns true if CST is minus one. */ 166 167 static inline bool 168 double_int_minus_one_p (double_int cst) 169 { 170 return (cst.low == ALL_ONES && cst.high == -1); 171 } 172 173 /* Returns true if CST1 == CST2. */ 174 175 static inline bool 176 double_int_equal_p (double_int cst1, double_int cst2) 177 { 178 return cst1.low == cst2.low && cst1.high == cst2.high; 179 } 180 181 #ifndef GENERATOR_FILE 182 /* Conversion to and from GMP integer representations. */ 183 184 void mpz_set_double_int (mpz_t, double_int, bool); 185 double_int mpz_get_double_int (const_tree, mpz_t, bool); 186 #endif 187 188 #endif /* DOUBLE_INT_H */ 189
