Mercurial > hg > CbC > CbC_gcc
diff gcc/double-int.h @ 0:a06113de4d67
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author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
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children | 77e2b8dfacca |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gcc/double-int.h Fri Jul 17 14:47:48 2009 +0900 @@ -0,0 +1,188 @@ +/* Operations with long integers. + Copyright (C) 2006, 2007, 2008 Free Software Foundation, Inc. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it +under the terms of the GNU General Public License as published by the +Free Software Foundation; either version 3, or (at your option) any +later version. + +GCC is distributed in the hope that it will be useful, but WITHOUT +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#ifndef DOUBLE_INT_H +#define DOUBLE_INT_H + +#ifndef GENERATOR_FILE +#include <gmp.h> +#endif +#include "coretypes.h" + +/* A large integer is currently represented as a pair of HOST_WIDE_INTs. + It therefore represents a number with precision of + 2 * HOST_BITS_PER_WIDE_INT bits (it is however possible that the + internal representation will change, if numbers with greater precision + are needed, so the users should not rely on it). The representation does + not contain any information about signedness of the represented value, so + it can be used to represent both signed and unsigned numbers. For + operations where the results depend on signedness (division, comparisons), + it must be specified separately. For each such operation, there are three + versions of the function -- double_int_op, that takes an extra UNS argument + giving the signedness of the values, and double_int_sop and double_int_uop + that stand for its specializations for signed and unsigned values. + + You may also represent with numbers in smaller precision using double_int. + You however need to use double_int_ext (that fills in the bits of the + number over the prescribed precision with zeros or with the sign bit) before + operations that do not perform arithmetics modulo 2^precision (comparisons, + division), and possibly before storing the results, if you want to keep + them in some canonical form). In general, the signedness of double_int_ext + should match the signedness of the operation. + + ??? The components of double_int differ in signedness mostly for + historical reasons (they replace an older structure used to represent + numbers with precision higher than HOST_WIDE_INT). It might be less + confusing to have them both signed or both unsigned. */ + +typedef struct +{ + unsigned HOST_WIDE_INT low; + HOST_WIDE_INT high; +} double_int; + +union tree_node; + +/* Constructors and conversions. */ + +union tree_node *double_int_to_tree (union tree_node *, double_int); +bool double_int_fits_to_tree_p (const union tree_node *, double_int); +double_int tree_to_double_int (const union tree_node *); + +/* Constructs double_int from integer CST. The bits over the precision of + HOST_WIDE_INT are filled with the sign bit. */ + +static inline double_int +shwi_to_double_int (HOST_WIDE_INT cst) +{ + double_int r; + + r.low = (unsigned HOST_WIDE_INT) cst; + r.high = cst < 0 ? -1 : 0; + + return r; +} + +/* Some useful constants. */ + +#define double_int_minus_one (shwi_to_double_int (-1)) +#define double_int_zero (shwi_to_double_int (0)) +#define double_int_one (shwi_to_double_int (1)) +#define double_int_two (shwi_to_double_int (2)) +#define double_int_ten (shwi_to_double_int (10)) + +/* Constructs double_int from unsigned integer CST. The bits over the + precision of HOST_WIDE_INT are filled with zeros. */ + +static inline double_int +uhwi_to_double_int (unsigned HOST_WIDE_INT cst) +{ + double_int r; + + r.low = cst; + r.high = 0; + + return r; +} + +/* The following operations perform arithmetics modulo 2^precision, + so you do not need to call double_int_ext between them, even if + you are representing numbers with precision less than + 2 * HOST_BITS_PER_WIDE_INT bits. */ + +double_int double_int_mul (double_int, double_int); +double_int double_int_add (double_int, double_int); +double_int double_int_neg (double_int); + +/* You must ensure that double_int_ext is called on the operands + of the following operations, if the precision of the numbers + is less than 2 * HOST_BITS_PER_WIDE_INT bits. */ +bool double_int_fits_in_hwi_p (double_int, bool); +bool double_int_fits_in_shwi_p (double_int); +bool double_int_fits_in_uhwi_p (double_int); +HOST_WIDE_INT double_int_to_shwi (double_int); +unsigned HOST_WIDE_INT double_int_to_uhwi (double_int); +double_int double_int_div (double_int, double_int, bool, unsigned); +double_int double_int_sdiv (double_int, double_int, unsigned); +double_int double_int_udiv (double_int, double_int, unsigned); +double_int double_int_mod (double_int, double_int, bool, unsigned); +double_int double_int_smod (double_int, double_int, unsigned); +double_int double_int_umod (double_int, double_int, unsigned); +double_int double_int_divmod (double_int, double_int, bool, unsigned, double_int *); +double_int double_int_sdivmod (double_int, double_int, unsigned, double_int *); +double_int double_int_udivmod (double_int, double_int, unsigned, double_int *); +bool double_int_negative_p (double_int); +int double_int_cmp (double_int, double_int, bool); +int double_int_scmp (double_int, double_int); +int double_int_ucmp (double_int, double_int); +void dump_double_int (FILE *, double_int, bool); + +/* Zero and sign extension of numbers in smaller precisions. */ + +double_int double_int_ext (double_int, unsigned, bool); +double_int double_int_sext (double_int, unsigned); +double_int double_int_zext (double_int, unsigned); +double_int double_int_mask (unsigned); + +#define ALL_ONES (~((unsigned HOST_WIDE_INT) 0)) + +/* The operands of the following comparison functions must be processed + with double_int_ext, if their precision is less than + 2 * HOST_BITS_PER_WIDE_INT bits. */ + +/* Returns true if CST is zero. */ + +static inline bool +double_int_zero_p (double_int cst) +{ + return cst.low == 0 && cst.high == 0; +} + +/* Returns true if CST is one. */ + +static inline bool +double_int_one_p (double_int cst) +{ + return cst.low == 1 && cst.high == 0; +} + +/* Returns true if CST is minus one. */ + +static inline bool +double_int_minus_one_p (double_int cst) +{ + return (cst.low == ALL_ONES && cst.high == -1); +} + +/* Returns true if CST1 == CST2. */ + +static inline bool +double_int_equal_p (double_int cst1, double_int cst2) +{ + return cst1.low == cst2.low && cst1.high == cst2.high; +} + +#ifndef GENERATOR_FILE +/* Conversion to and from GMP integer representations. */ + +void mpz_set_double_int (mpz_t, double_int, bool); +double_int mpz_get_double_int (const_tree, mpz_t, bool); +#endif + +#endif /* DOUBLE_INT_H */