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Diffstat (limited to 'include/ruby/internal/arithmetic/long.h')
| -rw-r--r-- | include/ruby/internal/arithmetic/long.h | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/include/ruby/internal/arithmetic/long.h b/include/ruby/internal/arithmetic/long.h new file mode 100644 index 0000000000..6c00dbceb7 --- /dev/null +++ b/include/ruby/internal/arithmetic/long.h @@ -0,0 +1,356 @@ +#ifndef RBIMPL_ARITHMETIC_LONG_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RBIMPL_ARITHMETIC_LONG_H +/** + * @file + * @author Ruby developers <ruby-core@ruby-lang.org> + * @copyright This file is a part of the programming language Ruby. + * Permission is hereby granted, to either redistribute and/or + * modify this file, provided that the conditions mentioned in the + * file COPYING are met. Consult the file for details. + * @warning Symbols prefixed with either `RBIMPL` or `rbimpl` are + * implementation details. Don't take them as canon. They could + * rapidly appear then vanish. The name (path) of this header file + * is also an implementation detail. Do not expect it to persist + * at the place it is now. Developers are free to move it anywhere + * anytime at will. + * @note To ruby-core: remember that this header can be possibly + * recursively included from extension libraries written in C++. + * Do not expect for instance `__VA_ARGS__` is always available. + * We assume C99 for ruby itself but we don't assume languages of + * extension libraries. They could be written in C++98. + * @brief Arithmetic conversion between C's `long` and Ruby's. + * + * ### Q&A ### + * + * - Q: Why are INT2FIX etc. here, not in `int.h`? + * + * - A: Because they are in fact handling `long`. It seems someone did not + * understand the difference of `int` and `long` when they designed those + * macros. + */ +#include "ruby/internal/config.h" +#include "ruby/internal/arithmetic/fixnum.h" /* FIXABLE */ +#include "ruby/internal/arithmetic/intptr_t.h" /* rb_int2big etc.*/ +#include "ruby/internal/assume.h" +#include "ruby/internal/attr/artificial.h" +#include "ruby/internal/attr/cold.h" +#include "ruby/internal/attr/const.h" +#include "ruby/internal/attr/constexpr.h" +#include "ruby/internal/attr/noreturn.h" +#include "ruby/internal/cast.h" +#include "ruby/internal/dllexport.h" +#include "ruby/internal/special_consts.h" /* FIXNUM_FLAG */ +#include "ruby/internal/value.h" +#include "ruby/assert.h" + +#define FIX2LONG RB_FIX2LONG /**< @old{RB_FIX2LONG} */ +#define FIX2ULONG RB_FIX2ULONG /**< @old{RB_FIX2ULONG} */ +#define INT2FIX RB_INT2FIX /**< @old{RB_INT2FIX} */ +#define LONG2FIX RB_INT2FIX /**< @old{RB_INT2FIX} */ +#define LONG2NUM RB_LONG2NUM /**< @old{RB_LONG2NUM} */ +#define NUM2LONG RB_NUM2LONG /**< @old{RB_NUM2LONG} */ +#define NUM2ULONG RB_NUM2ULONG /**< @old{RB_NUM2ULONG} */ +#define RB_FIX2LONG rb_fix2long /**< @alias{rb_fix2long} */ +#define RB_FIX2ULONG rb_fix2ulong /**< @alias{rb_fix2ulong} */ +#define RB_LONG2FIX RB_INT2FIX /**< @alias{RB_INT2FIX} */ +#define RB_LONG2NUM rb_long2num_inline /**< @alias{rb_long2num_inline} */ +#define RB_NUM2LONG rb_num2long_inline /**< @alias{rb_num2long_inline} */ +#define RB_NUM2ULONG rb_num2ulong_inline /**< @alias{rb_num2ulong_inline} */ +#define RB_ULONG2NUM rb_ulong2num_inline /**< @alias{rb_ulong2num_inline} */ +#define ULONG2NUM RB_ULONG2NUM /**< @old{RB_ULONG2NUM} */ +#define rb_fix_new RB_INT2FIX /**< @alias{RB_INT2FIX} */ +#define rb_long2int rb_long2int_inline /**< @alias{rb_long2int_inline} */ + +/** @cond INTERNAL_MACRO */ +#define RB_INT2FIX RB_INT2FIX +/** @endcond */ + +RBIMPL_SYMBOL_EXPORT_BEGIN() + +RBIMPL_ATTR_NORETURN() +RBIMPL_ATTR_COLD() +/** + * This is an utility function to raise an ::rb_eRangeError. + * + * @param[in] num A signed value about to overflow. + * @exception rb_eRangeError `num` is out of range of `int`. + */ +void rb_out_of_int(SIGNED_VALUE num); + +/** + * Converts an instance of ::rb_cNumeric into C's `long`. + * + * @param[in] num Something numeric. + * @exception rb_eTypeError `num` is not a numeric. + * @exception rb_eRangeError `num` is out of range of `long`. + * @return The passed value converted into C's `long`. + */ +long rb_num2long(VALUE num); + +/** + * Converts an instance of ::rb_cNumeric into C's `unsigned long`. + * + * @param[in] num Something numeric. + * @exception rb_eTypeError `num` is not a numeric. + * @exception rb_eRangeError `num` is out of range of `unsigned long`. + * @return The passed value converted into C's `unsigned long`. + */ +unsigned long rb_num2ulong(VALUE num); +RBIMPL_SYMBOL_EXPORT_END() + +RBIMPL_ATTR_CONST_UNLESS_DEBUG() +RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14) +RBIMPL_ATTR_ARTIFICIAL() +/** + * Converts a C's `long` into an instance of ::rb_cInteger. + * + * @param[in] i Arbitrary `long` value. + * @return An instance of ::rb_cInteger. + */ +static inline VALUE +RB_INT2FIX(long i) +{ + RBIMPL_ASSERT_OR_ASSUME(RB_FIXABLE(i)); + + /* :NOTE: VALUE can be wider than long. As j being unsigned, 2j+1 is fully + * defined. Also it can be compiled into a single LEA instruction. */ + const unsigned long j = RBIMPL_CAST((unsigned long)i); + const unsigned long k = (j << 1) + RUBY_FIXNUM_FLAG; + const long l = RBIMPL_CAST((long)k); + const SIGNED_VALUE m = l; /* Sign extend */ + const VALUE n = RBIMPL_CAST((VALUE)m); + + RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(n)); + return n; +} + +/** + * Checks if `int` can hold the given integer. + * + * @param[in] n Arbitrary `long` value. + * @exception rb_eRangeError `n` is out of range of `int`. + * @return Identical value of type `int` + */ +static inline int +rb_long2int_inline(long n) +{ + int i = RBIMPL_CAST((int)n); + + if /* constexpr */ (sizeof(long) <= sizeof(int)) { + RBIMPL_ASSUME(i == n); + } + + if (i != n) + rb_out_of_int(n); + + return i; +} + +RBIMPL_ATTR_CONST_UNLESS_DEBUG() +RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14) +/** + * @private + * + * This is an implementation detail of rb_fix2long(). People don't use it + * directly. + * + * @param[in] x A Fixnum. + * @return Identical value of type `long` + * @pre Must not pass anything other than a Fixnum. + */ +static inline long +rbimpl_fix2long_by_idiv(VALUE x) +{ + RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(x)); + + /* :NOTE: VALUE can be wider than long. (x-1)/2 never overflows because + * RB_FIXNUM_P(x) holds. Also it has no portability issue like y>>1 + * below. */ + const SIGNED_VALUE y = RBIMPL_CAST((SIGNED_VALUE)(x - RUBY_FIXNUM_FLAG)); + const SIGNED_VALUE z = y / 2; + const long w = RBIMPL_CAST((long)z); + + RBIMPL_ASSERT_OR_ASSUME(RB_FIXABLE(w)); + return w; +} + +RBIMPL_ATTR_CONST_UNLESS_DEBUG() +RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14) +/** + * @private + * + * This is an implementation detail of rb_fix2long(). People don't use it + * directly. + * + * @param[in] x A Fixnum. + * @return Identical value of type `long` + * @pre Must not pass anything other than a Fixnum. + */ +static inline long +rbimpl_fix2long_by_shift(VALUE x) +{ + RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(x)); + + /* :NOTE: VALUE can be wider than long. If right shift is arithmetic, this + * is noticeably faster than above. */ + const SIGNED_VALUE y = RBIMPL_CAST((SIGNED_VALUE)x); + const SIGNED_VALUE z = y >> 1; + const long w = RBIMPL_CAST((long)z); + + RBIMPL_ASSERT_OR_ASSUME(RB_FIXABLE(w)); + return w; +} + +RBIMPL_ATTR_CONST() +RBIMPL_ATTR_CONSTEXPR(CXX11) +/** + * @private + * + * This is an implementation detail of rb_fix2long(). People don't use it + * directly. + * + * @retval true This C compiler's right shift operator is arithmetic. + * @retval false This C compiler's right shift operator is logical. + */ +static inline bool +rbimpl_right_shift_is_arithmetic_p(void) +{ + return (-1 >> 1) == -1; +} + +RBIMPL_ATTR_CONST_UNLESS_DEBUG() +RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14) +/** + * Converts a Fixnum into C's `long`. + * + * @param[in] x Some Fixnum. + * @pre Must not pass anything other than a Fixnum. + * @return The passed value converted into C's `long`. + */ +static inline long +rb_fix2long(VALUE x) +{ + if /* constexpr */ (rbimpl_right_shift_is_arithmetic_p()) { + return rbimpl_fix2long_by_shift(x); + } + else { + return rbimpl_fix2long_by_idiv(x); + } +} + +RBIMPL_ATTR_CONST_UNLESS_DEBUG() +RBIMPL_ATTR_CONSTEXPR_UNLESS_DEBUG(CXX14) +/** + * Converts a Fixnum into C's `unsigned long`. + * + * @param[in] x Some Fixnum. + * @pre Must not pass anything other than a Fixnum. + * @return The passed value converted into C's `unsigned long`. + * @note Negative fixnums will be converted into large unsigned longs. + */ +static inline unsigned long +rb_fix2ulong(VALUE x) +{ + RBIMPL_ASSERT_OR_ASSUME(RB_FIXNUM_P(x)); + return RBIMPL_CAST((unsigned long)rb_fix2long(x)); +} + +/** + * Converts an instance of ::rb_cNumeric into C's `long`. + * + * @param[in] x Something numeric. + * @exception rb_eTypeError `x` is not a numeric. + * @exception rb_eRangeError `x` is out of range of `long`. + * @return The passed value converted into C's `long`. + */ +static inline long +rb_num2long_inline(VALUE x) +{ + if (RB_FIXNUM_P(x)) + return RB_FIX2LONG(x); + else + return rb_num2long(x); +} + +/** + * Converts an instance of ::rb_cNumeric into C's `unsigned long`. + * + * @param[in] x Something numeric. + * @exception rb_eTypeError `x` is not a numeric. + * @exception rb_eRangeError `x` is out of range of `unsigned long`. + * @return The passed value converted into C's `unsigned long`. + * + * @internal + * + * This (negative fixnum would become a large unsigned long while negative + * bignum is an exception) has been THE behaviour of NUM2ULONG since the + * beginning. It is strange, but we can no longer change how it works at this + * moment. We have to get by with it. + * + * @see https://bugs.ruby-lang.org/issues/9089 + */ +static inline unsigned long +rb_num2ulong_inline(VALUE x) +{ + if (RB_FIXNUM_P(x)) + return RB_FIX2ULONG(x); + else + return rb_num2ulong(x); +} + +/** + * Converts a C's `long` into an instance of ::rb_cInteger. + * + * @param[in] v Arbitrary `long` value. + * @return An instance of ::rb_cInteger. + */ +static inline VALUE +rb_long2num_inline(long v) +{ + if (RB_FIXABLE(v)) + return RB_LONG2FIX(v); + else + return rb_int2big(v); +} + +/** + * Converts a C's `unsigned long` into an instance of ::rb_cInteger. + * + * @param[in] v Arbitrary `unsigned long` value. + * @return An instance of ::rb_cInteger. + */ +static inline VALUE +rb_ulong2num_inline(unsigned long v) +{ + if (RB_POSFIXABLE(v)) + return RB_LONG2FIX(RBIMPL_CAST((long)v)); + else + return rb_uint2big(v); +} + +/** + * @cond INTERNAL_MACRO + * + * Following overload is necessary because sometimes INT2FIX is used as a enum + * value (e.g. `enum { FOO = INT2FIX(0) };`). THIS IS NG in theory because a + * VALUE does not fit into an enum (which must be a signed int). But we cannot + * break existing codes. + */ +#if RBIMPL_HAS_ATTR_CONSTEXPR_CXX14 +# /* C++ can write constexpr as enum values. */ + +#elif ! defined(HAVE_BUILTIN___BUILTIN_CHOOSE_EXPR_CONSTANT_P) +# undef INT2FIX +# define INT2FIX(i) (RBIMPL_CAST((VALUE)(i)) << 1 | RUBY_FIXNUM_FLAG) + +#else +# undef INT2FIX +# define INT2FIX(i) \ + __builtin_choose_expr( \ + __builtin_constant_p(i), \ + RBIMPL_CAST((VALUE)(i)) << 1 | RUBY_FIXNUM_FLAG, \ + RB_INT2FIX(i)) +#endif +/** @endcond */ + +#endif /* RBIMPL_ARITHMETIC_LONG_H */ |