/* Operations with long integers. | |

Copyright (C) 2006-2021 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 | |

/* 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. */ | |

struct double_int | |

{ | |

/* Normally, we would define constructors to create instances. | |

Two things prevent us from doing so. | |

First, defining a constructor makes the class non-POD in C++03, | |

and we certainly want double_int to be a POD. | |

Second, the GCC conding conventions prefer explicit conversion, | |

and explicit conversion operators are not available until C++11. */ | |

static double_int from_uhwi (unsigned HOST_WIDE_INT cst); | |

static double_int from_shwi (HOST_WIDE_INT cst); | |

static double_int from_pair (HOST_WIDE_INT high, unsigned HOST_WIDE_INT low); | |

/* Construct from a fuffer of length LEN. BUFFER will be read according | |

to byte endianness and word endianness. */ | |

static double_int from_buffer (const unsigned char *buffer, int len); | |

/* No copy assignment operator or destructor to keep the type a POD. */ | |

/* There are some special value-creation static member functions. */ | |

static double_int mask (unsigned prec); | |

static double_int max_value (unsigned int prec, bool uns); | |

static double_int min_value (unsigned int prec, bool uns); | |

/* The following functions are mutating operations. */ | |

double_int &operator ++ (); // prefix | |

double_int &operator -- (); // prefix | |

double_int &operator *= (double_int); | |

double_int &operator += (double_int); | |

double_int &operator -= (double_int); | |

double_int &operator &= (double_int); | |

double_int &operator ^= (double_int); | |

double_int &operator |= (double_int); | |

/* The following functions are non-mutating operations. */ | |

/* Conversion functions. */ | |

HOST_WIDE_INT to_shwi () const; | |

unsigned HOST_WIDE_INT to_uhwi () const; | |

/* Conversion query functions. */ | |

bool fits_uhwi () const; | |

bool fits_shwi () const; | |

bool fits_hwi (bool uns) const; | |

/* Attribute query functions. */ | |

int trailing_zeros () const; | |

int popcount () const; | |

/* Arithmetic query operations. */ | |

bool multiple_of (double_int, bool, double_int *) const; | |

/* Arithmetic operation functions. */ | |

/* The following operations perform arithmetics modulo 2^precision, so you | |

do not need to call .ext between them, even if you are representing | |

numbers with precision less than HOST_BITS_PER_DOUBLE_INT bits. */ | |

double_int set_bit (unsigned) const; | |

double_int mul_with_sign (double_int, bool unsigned_p, bool *overflow) const; | |

double_int wide_mul_with_sign (double_int, bool unsigned_p, | |

double_int *higher, bool *overflow) const; | |

double_int add_with_sign (double_int, bool unsigned_p, bool *overflow) const; | |

double_int sub_with_overflow (double_int, bool *overflow) const; | |

double_int neg_with_overflow (bool *overflow) const; | |

double_int operator * (double_int) const; | |

double_int operator + (double_int) const; | |

double_int operator - (double_int) const; | |

double_int operator - () const; | |

double_int operator ~ () const; | |

double_int operator & (double_int) const; | |

double_int operator | (double_int) const; | |

double_int operator ^ (double_int) const; | |

double_int and_not (double_int) const; | |

double_int lshift (HOST_WIDE_INT count) const; | |

double_int lshift (HOST_WIDE_INT count, unsigned int prec, bool arith) const; | |

double_int rshift (HOST_WIDE_INT count) const; | |

double_int rshift (HOST_WIDE_INT count, unsigned int prec, bool arith) const; | |

double_int alshift (HOST_WIDE_INT count, unsigned int prec) const; | |

double_int arshift (HOST_WIDE_INT count, unsigned int prec) const; | |

double_int llshift (HOST_WIDE_INT count, unsigned int prec) const; | |

double_int lrshift (HOST_WIDE_INT count, unsigned int prec) const; | |

double_int lrotate (HOST_WIDE_INT count, unsigned int prec) const; | |

double_int rrotate (HOST_WIDE_INT count, unsigned int prec) const; | |

/* 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 HOST_BITS_PER_DOUBLE_INT bits. */ | |

double_int div (double_int, bool, unsigned) const; | |

double_int sdiv (double_int, unsigned) const; | |

double_int udiv (double_int, unsigned) const; | |

double_int mod (double_int, bool, unsigned) const; | |

double_int smod (double_int, unsigned) const; | |

double_int umod (double_int, unsigned) const; | |

double_int divmod_with_overflow (double_int, bool, unsigned, | |

double_int *, bool *) const; | |

double_int divmod (double_int, bool, unsigned, double_int *) const; | |

double_int sdivmod (double_int, unsigned, double_int *) const; | |

double_int udivmod (double_int, unsigned, double_int *) const; | |

/* Precision control functions. */ | |

double_int ext (unsigned prec, bool uns) const; | |

double_int zext (unsigned prec) const; | |

double_int sext (unsigned prec) const; | |

/* Comparative functions. */ | |

bool is_zero () const; | |

bool is_one () const; | |

bool is_minus_one () const; | |

bool is_negative () const; | |

int cmp (double_int b, bool uns) const; | |

int ucmp (double_int b) const; | |

int scmp (double_int b) const; | |

bool ult (double_int b) const; | |

bool ule (double_int b) const; | |

bool ugt (double_int b) const; | |

bool slt (double_int b) const; | |

bool sle (double_int b) const; | |

bool sgt (double_int b) const; | |

double_int max (double_int b, bool uns); | |

double_int smax (double_int b); | |

double_int umax (double_int b); | |

double_int min (double_int b, bool uns); | |

double_int smin (double_int b); | |

double_int umin (double_int b); | |

bool operator == (double_int cst2) const; | |

bool operator != (double_int cst2) const; | |

/* Please migrate away from using these member variables publicly. */ | |

unsigned HOST_WIDE_INT low; | |

HOST_WIDE_INT high; | |

}; | |

#define HOST_BITS_PER_DOUBLE_INT (2 * HOST_BITS_PER_WIDE_INT) | |

/* Constructors and conversions. */ | |

/* Constructs double_int from integer CST. The bits over the precision of | |

HOST_WIDE_INT are filled with the sign bit. */ | |

inline double_int | |

double_int::from_shwi (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. */ | |

/* FIXME(crowl): Maybe remove after converting callers? | |

The problem is that a named constant would not be as optimizable, | |

while the functional syntax is more verbose. */ | |

#define double_int_minus_one (double_int::from_shwi (-1)) | |

#define double_int_zero (double_int::from_shwi (0)) | |

#define double_int_one (double_int::from_shwi (1)) | |

#define double_int_two (double_int::from_shwi (2)) | |

#define double_int_ten (double_int::from_shwi (10)) | |

/* Constructs double_int from unsigned integer CST. The bits over the | |

precision of HOST_WIDE_INT are filled with zeros. */ | |

inline double_int | |

double_int::from_uhwi (unsigned HOST_WIDE_INT cst) | |

{ | |

double_int r; | |

r.low = cst; | |

r.high = 0; | |

return r; | |

} | |

inline double_int | |

double_int::from_pair (HOST_WIDE_INT high, unsigned HOST_WIDE_INT low) | |

{ | |

double_int r; | |

r.low = low; | |

r.high = high; | |

return r; | |

} | |

inline double_int & | |

double_int::operator ++ () | |

{ | |

*this += double_int_one; | |

return *this; | |

} | |

inline double_int & | |

double_int::operator -- () | |

{ | |

*this -= double_int_one; | |

return *this; | |

} | |

inline double_int & | |

double_int::operator &= (double_int b) | |

{ | |

*this = *this & b; | |

return *this; | |

} | |

inline double_int & | |

double_int::operator ^= (double_int b) | |

{ | |

*this = *this ^ b; | |

return *this; | |

} | |

inline double_int & | |

double_int::operator |= (double_int b) | |

{ | |

*this = *this | b; | |

return *this; | |

} | |

/* Returns value of CST as a signed number. CST must satisfy | |

double_int::fits_signed. */ | |

inline HOST_WIDE_INT | |

double_int::to_shwi () const | |

{ | |

return (HOST_WIDE_INT) low; | |

} | |

/* Returns value of CST as an unsigned number. CST must satisfy | |

double_int::fits_unsigned. */ | |

inline unsigned HOST_WIDE_INT | |

double_int::to_uhwi () const | |

{ | |

return low; | |

} | |

/* Returns true if CST fits in unsigned HOST_WIDE_INT. */ | |

inline bool | |

double_int::fits_uhwi () const | |

{ | |

return high == 0; | |

} | |

/* Logical operations. */ | |

/* Returns ~A. */ | |

inline double_int | |

double_int::operator ~ () const | |

{ | |

double_int result; | |

result.low = ~low; | |

result.high = ~high; | |

return result; | |

} | |

/* Returns A | B. */ | |

inline double_int | |

double_int::operator | (double_int b) const | |

{ | |

double_int result; | |

result.low = low | b.low; | |

result.high = high | b.high; | |

return result; | |

} | |

/* Returns A & B. */ | |

inline double_int | |

double_int::operator & (double_int b) const | |

{ | |

double_int result; | |

result.low = low & b.low; | |

result.high = high & b.high; | |

return result; | |

} | |

/* Returns A & ~B. */ | |

inline double_int | |

double_int::and_not (double_int b) const | |

{ | |

double_int result; | |

result.low = low & ~b.low; | |

result.high = high & ~b.high; | |

return result; | |

} | |

/* Returns A ^ B. */ | |

inline double_int | |

double_int::operator ^ (double_int b) const | |

{ | |

double_int result; | |

result.low = low ^ b.low; | |

result.high = high ^ b.high; | |

return result; | |

} | |

void dump_double_int (FILE *, double_int, bool); | |

#define ALL_ONES HOST_WIDE_INT_M1U | |

/* The operands of the following comparison functions must be processed | |

with double_int_ext, if their precision is less than | |

HOST_BITS_PER_DOUBLE_INT bits. */ | |

/* Returns true if CST is zero. */ | |

inline bool | |

double_int::is_zero () const | |

{ | |

return low == 0 && high == 0; | |

} | |

/* Returns true if CST is one. */ | |

inline bool | |

double_int::is_one () const | |

{ | |

return low == 1 && high == 0; | |

} | |

/* Returns true if CST is minus one. */ | |

inline bool | |

double_int::is_minus_one () const | |

{ | |

return low == ALL_ONES && high == -1; | |

} | |

/* Returns true if CST is negative. */ | |

inline bool | |

double_int::is_negative () const | |

{ | |

return high < 0; | |

} | |

/* Returns true if CST1 == CST2. */ | |

inline bool | |

double_int::operator == (double_int cst2) const | |

{ | |

return low == cst2.low && high == cst2.high; | |

} | |

/* Returns true if CST1 != CST2. */ | |

inline bool | |

double_int::operator != (double_int cst2) const | |

{ | |

return low != cst2.low || high != cst2.high; | |

} | |

/* Return number of set bits of CST. */ | |

inline int | |

double_int::popcount () const | |

{ | |

return popcount_hwi (high) + popcount_hwi (low); | |

} | |

#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 | |

namespace wi | |

{ | |

template <> | |

struct int_traits <double_int> | |

{ | |

static const enum precision_type precision_type = CONST_PRECISION; | |

static const bool host_dependent_precision = true; | |

static const unsigned int precision = HOST_BITS_PER_DOUBLE_INT; | |

static unsigned int get_precision (const double_int &); | |

static wi::storage_ref decompose (HOST_WIDE_INT *, unsigned int, | |

const double_int &); | |

}; | |

} | |

inline unsigned int | |

wi::int_traits <double_int>::get_precision (const double_int &) | |

{ | |

return precision; | |

} | |

inline wi::storage_ref | |

wi::int_traits <double_int>::decompose (HOST_WIDE_INT *scratch, unsigned int p, | |

const double_int &x) | |

{ | |

gcc_checking_assert (precision == p); | |

scratch[0] = x.low; | |

if ((x.high == 0 && scratch[0] >= 0) || (x.high == -1 && scratch[0] < 0)) | |

return wi::storage_ref (scratch, 1, precision); | |

scratch[1] = x.high; | |

return wi::storage_ref (scratch, 2, precision); | |

} | |

#endif /* DOUBLE_INT_H */ |