1172302Spjd/* Operations with long integers. 2172302Spjd Copyright (C) 2006 Free Software Foundation, Inc. 3172302Spjd 4172302SpjdThis file is part of GCC. 5172302Spjd 6172302SpjdGCC is free software; you can redistribute it and/or modify it 7172302Spjdunder the terms of the GNU General Public License as published by the 8172302SpjdFree Software Foundation; either version 2, or (at your option) any 9172302Spjdlater version. 10172302Spjd 11172302SpjdGCC is distributed in the hope that it will be useful, but WITHOUT 12172302SpjdANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13172302SpjdFITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14172302Spjdfor more details. 15172302Spjd 16172302SpjdYou should have received a copy of the GNU General Public License 17172302Spjdalong with GCC; see the file COPYING. If not, write to the Free 18172302SpjdSoftware Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 19172302Spjd02110-1301, USA. */ 20172302Spjd 21172302Spjd#ifndef DOUBLE_INT_H 22172302Spjd#define DOUBLE_INT_H 23172302Spjd 24172302Spjd/* A large integer is currently represented as a pair of HOST_WIDE_INTs. 25172302Spjd It therefore represents a number with precision of 26172302Spjd 2 * HOST_BITS_PER_WIDE_INT bits (it is however possible that the 27172302Spjd internal representation will change, if numbers with greater precision 28172302Spjd are needed, so the users should not rely on it). The representation does 29172302Spjd not contain any information about signedness of the represented value, so 30172302Spjd it can be used to represent both signed and unsigned numbers. For 31172302Spjd operations where the results depend on signedness (division, comparisons), 32172302Spjd it must be specified separately. For each such operation, there are three 33172302Spjd versions of the function -- double_int_op, that takes an extra UNS argument 34172302Spjd giving the signedness of the values, and double_int_sop and double_int_uop 35172302Spjd that stand for its specializations for signed and unsigned values. 36172302Spjd 37172302Spjd You may also represent with numbers in smaller precision using double_int. 38172302Spjd You however need to use double_int_ext (that fills in the bits of the 39172302Spjd number over the prescribed precision with zeros or with the sign bit) before 40172302Spjd operations that do not perform arithmetics modulo 2^precision (comparisons, 41172302Spjd division), and possibly before storing the results, if you want to keep 42172302Spjd them in some canonical form). In general, the signedness of double_int_ext 43172302Spjd should match the signedness of the operation. 44172302Spjd 45172302Spjd ??? The components of double_int differ in signedness mostly for 46172302Spjd historical reasons (they replace an older structure used to represent 47172302Spjd numbers with precision higher than HOST_WIDE_INT). It might be less 48172302Spjd confusing to have them both signed or both unsigned. */ 49172302Spjd 50172302Spjdtypedef struct 51172302Spjd{ 52172302Spjd unsigned HOST_WIDE_INT low; 53172302Spjd HOST_WIDE_INT high; 54172302Spjd} double_int; 55172302Spjd 56172302Spjdunion tree_node; 57172302Spjd 58172302Spjd/* Constructors and conversions. */ 59172302Spjd 60172302Spjdunion tree_node *double_int_to_tree (union tree_node *, double_int); 61172302Spjddouble_int tree_to_double_int (union tree_node *tree); 62172302Spjd 63172302Spjd/* Constructs double_int from integer CST. The bits over the precision of 64172302Spjd HOST_WIDE_INT are filled with the sign bit. */ 65172302Spjd 66172302Spjdstatic inline double_int 67172302Spjdshwi_to_double_int (HOST_WIDE_INT cst) 68172302Spjd{ 69172302Spjd double_int r; 70172302Spjd 71172302Spjd r.low = (unsigned HOST_WIDE_INT) cst; 72172302Spjd r.high = cst < 0 ? -1 : 0; 73172302Spjd 74172302Spjd return r; 75172302Spjd} 76172302Spjd 77172302Spjd/* Some useful constants. */ 78172302Spjd 79172302Spjd#define double_int_minus_one (shwi_to_double_int (-1)) 80172302Spjd#define double_int_zero (shwi_to_double_int (0)) 81172302Spjd#define double_int_one (shwi_to_double_int (1)) 82172302Spjd#define double_int_two (shwi_to_double_int (2)) 83172302Spjd#define double_int_ten (shwi_to_double_int (10)) 84172302Spjd 85172302Spjd/* Constructs double_int from unsigned integer CST. The bits over the 86172302Spjd precision of HOST_WIDE_INT are filled with zeros. */ 87172302Spjd 88172302Spjdstatic inline double_int 89172302Spjduhwi_to_double_int (unsigned HOST_WIDE_INT cst) 90172302Spjd{ 91172302Spjd double_int r; 92172302Spjd 93172302Spjd r.low = cst; 94172302Spjd r.high = 0; 95172302Spjd 96172302Spjd return r; 97172302Spjd} 98172302Spjd 99172302Spjd/* The following operations perform arithmetics modulo 2^precision, 100172302Spjd so you do not need to call double_int_ext between them, even if 101172302Spjd you are representing numbers with precision less than 102172302Spjd 2 * HOST_BITS_PER_WIDE_INT bits. */ 103172302Spjd 104172302Spjddouble_int double_int_mul (double_int, double_int); 105172302Spjddouble_int double_int_add (double_int, double_int); 106172302Spjddouble_int double_int_neg (double_int); 107172302Spjd 108172302Spjd/* You must ensure that double_int_ext is called on the operands 109172302Spjd of the following operations, if the precision of the numbers 110172302Spjd is less than 2 * HOST_BITS_PER_WIDE_INT bits. */ 111172302Spjdbool double_int_fits_in_hwi_p (double_int, bool); 112172302Spjdbool double_int_fits_in_shwi_p (double_int); 113172302Spjdbool double_int_fits_in_uhwi_p (double_int); 114172302SpjdHOST_WIDE_INT double_int_to_shwi (double_int); 115172302Spjdunsigned HOST_WIDE_INT double_int_to_uhwi (double_int); 116172302Spjddouble_int double_int_div (double_int, double_int, bool, unsigned); 117172302Spjddouble_int double_int_sdiv (double_int, double_int, unsigned); 118172302Spjddouble_int double_int_udiv (double_int, double_int, unsigned); 119172302Spjddouble_int double_int_mod (double_int, double_int, bool, unsigned); 120172302Spjddouble_int double_int_smod (double_int, double_int, unsigned); 121172302Spjddouble_int double_int_umod (double_int, double_int, unsigned); 122172302Spjddouble_int double_int_divmod (double_int, double_int, bool, unsigned, double_int *); 123172302Spjddouble_int double_int_sdivmod (double_int, double_int, unsigned, double_int *); 124172302Spjddouble_int double_int_udivmod (double_int, double_int, unsigned, double_int *); 125172302Spjdbool double_int_negative_p (double_int); 126172302Spjdint double_int_cmp (double_int, double_int, bool); 127172302Spjdint double_int_scmp (double_int, double_int); 128172302Spjdint double_int_ucmp (double_int, double_int); 129172302Spjdvoid dump_double_int (FILE *, double_int, bool); 130172302Spjd 131172302Spjd/* Zero and sign extension of numbers in smaller precisions. */ 132172302Spjd 133172302Spjddouble_int double_int_ext (double_int, unsigned, bool); 134172302Spjddouble_int double_int_sext (double_int, unsigned); 135172302Spjddouble_int double_int_zext (double_int, unsigned); 136 137#define ALL_ONES (~((unsigned HOST_WIDE_INT) 0)) 138 139/* The operands of the following comparison functions must be processed 140 with double_int_ext, if their precision is less than 141 2 * HOST_BITS_PER_WIDE_INT bits. */ 142 143/* Returns true if CST is zero. */ 144 145static inline bool 146double_int_zero_p (double_int cst) 147{ 148 return cst.low == 0 && cst.high == 0; 149} 150 151/* Returns true if CST is one. */ 152 153static inline bool 154double_int_one_p (double_int cst) 155{ 156 return cst.low == 1 && cst.high == 0; 157} 158 159/* Returns true if CST is minus one. */ 160 161static inline bool 162double_int_minus_one_p (double_int cst) 163{ 164 return (cst.low == ALL_ONES && cst.high == -1); 165} 166 167/* Returns true if CST1 == CST2. */ 168 169static inline bool 170double_int_equal_p (double_int cst1, double_int cst2) 171{ 172 return cst1.low == cst2.low && cst1.high == cst2.high; 173} 174 175#endif /* DOUBLE_INT_H */ 176