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Diffstat (limited to 'include/ruby/impl/arithmetic/long.h')
| -rw-r--r-- | include/ruby/impl/arithmetic/long.h | 244 |
1 files changed, 244 insertions, 0 deletions
diff --git a/include/ruby/impl/arithmetic/long.h b/include/ruby/impl/arithmetic/long.h new file mode 100644 index 0000000000..3263c616b0 --- /dev/null +++ b/include/ruby/impl/arithmetic/long.h @@ -0,0 +1,244 @@ +#ifndef RUBY3_ARITHMETIC_LONG_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RUBY3_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 `RUBY3` or `ruby3` 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/3/config.h" +#include "ruby/3/arithmetic/fixnum.h" /* FIXABLE */ +#include "ruby/3/arithmetic/intptr_t.h" /* rb_int2big etc.*/ +#include "ruby/3/assume.h" +#include "ruby/3/attr/artificial.h" +#include "ruby/3/attr/cold.h" +#include "ruby/3/attr/const.h" +#include "ruby/3/attr/constexpr.h" +#include "ruby/3/attr/noreturn.h" +#include "ruby/3/cast.h" +#include "ruby/3/dllexport.h" +#include "ruby/3/special_consts.h" /* FIXNUM_FLAG */ +#include "ruby/3/value.h" +#include "ruby/assert.h" + +#define FIX2LONG RB_FIX2LONG +#define FIX2ULONG RB_FIX2ULONG +#define INT2FIX RB_INT2FIX +#define LONG2FIX RB_INT2FIX +#define LONG2NUM RB_LONG2NUM +#define NUM2LONG RB_NUM2LONG +#define NUM2ULONG RB_NUM2ULONG +#define RB_FIX2LONG rb_fix2long +#define RB_FIX2ULONG rb_fix2ulong +#define RB_LONG2FIX RB_INT2FIX +#define RB_LONG2NUM rb_long2num_inline +#define RB_NUM2LONG rb_num2long_inline +#define RB_NUM2ULONG rb_num2ulong_inline +#define RB_ULONG2NUM rb_ulong2num_inline +#define ULONG2NUM RB_ULONG2NUM +#define rb_fix_new RB_INT2FIX +#define rb_long2int rb_long2int_inline + +/** @cond INTERNAL_MACRO */ +#define RB_INT2FIX RB_INT2FIX +/** @endcond */ + +RUBY3_SYMBOL_EXPORT_BEGIN() + +RUBY3_ATTR_NORETURN() +RUBY3_ATTR_COLD() +void rb_out_of_int(SIGNED_VALUE num); + +long rb_num2long(VALUE num); +unsigned long rb_num2ulong(VALUE num); +RUBY3_SYMBOL_EXPORT_END() + +RUBY3_ATTR_CONST_ON_NDEBUG() +RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(CXX14) +RUBY3_ATTR_ARTIFICIAL() +static inline VALUE +RB_INT2FIX(long i) +{ + RUBY3_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 = i; + const unsigned long k = 2 * j + RUBY_FIXNUM_FLAG; + const long l = k; + const SIGNED_VALUE m = l; /* Sign extend */ + const VALUE n = m; + + RUBY3_ASSERT_OR_ASSUME(RB_FIXNUM_P(n)); + return n; +} + +static inline int +rb_long2int_inline(long n) +{ + int i = RUBY3_CAST((int)n); + + if /* constexpr */ (sizeof(long) <= sizeof(int)) { + RUBY3_ASSUME(i == n); + } + + if (i != n) + rb_out_of_int(n); + + return i; +} + +RUBY3_ATTR_CONST_ON_NDEBUG() +RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(CXX14) +static inline long +ruby3_fix2long_by_idiv(VALUE x) +{ + RUBY3_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 = x - RUBY_FIXNUM_FLAG; + const SIGNED_VALUE z = y / 2; + const long w = RUBY3_CAST((long)z); + + RUBY3_ASSERT_OR_ASSUME(RB_FIXABLE(w)); + return w; +} + +RUBY3_ATTR_CONST_ON_NDEBUG() +RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(CXX14) +static inline long +ruby3_fix2long_by_shift(VALUE x) +{ + RUBY3_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 = x; + const SIGNED_VALUE z = y >> 1; + const long w = RUBY3_CAST((long)z); + + RUBY3_ASSERT_OR_ASSUME(RB_FIXABLE(w)); + return w; +} + +RUBY3_ATTR_CONST() +RUBY3_ATTR_CONSTEXPR(CXX11) +static inline bool +ruby3_right_shift_is_arithmetic_p(void) +{ + return (-1 >> 1) == -1; +} + +RUBY3_ATTR_CONST_ON_NDEBUG() +RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(CXX14) +static inline long +rb_fix2long(VALUE x) +{ + if /* constexpr */ (ruby3_right_shift_is_arithmetic_p()) { + return ruby3_fix2long_by_shift(x); + } + else { + return ruby3_fix2long_by_idiv(x); + } +} + +RUBY3_ATTR_CONST_ON_NDEBUG() +RUBY3_ATTR_CONSTEXPR_ON_NDEBUG(CXX14) +static inline unsigned long +rb_fix2ulong(VALUE x) +{ + RUBY3_ASSERT_OR_ASSUME(RB_FIXNUM_P(x)); + return rb_fix2long(x); +} + +static inline long +rb_num2long_inline(VALUE x) +{ + if (RB_FIXNUM_P(x)) + return RB_FIX2LONG(x); + else + return rb_num2long(x); +} + +static inline unsigned long +rb_num2ulong_inline(VALUE x) +{ + /* 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 also: + * https://bugs.ruby-lang.org/issues/9089 */ + if (RB_FIXNUM_P(x)) + return RB_FIX2ULONG(x); + else + return rb_num2ulong(x); +} + +static inline VALUE +rb_long2num_inline(long v) +{ + if (RB_FIXABLE(v)) + return RB_LONG2FIX(v); + else + return rb_int2big(v); +} + +static inline VALUE +rb_ulong2num_inline(unsigned long v) +{ + if (RB_POSFIXABLE(v)) + return RB_LONG2FIX(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 RUBY3_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) (RUBY3_CAST((VALUE)(i)) << 1 | RUBY_FIXNUM_FLAG) + +#else +# undef INT2FIX +# define INT2FIX(i) \ + __builtin_choose_expr( \ + __builtin_constant_p(i), \ + RUBY3_CAST((VALUE)(i)) << 1 | RUBY_FIXNUM_FLAG, \ + RB_INT2FIX(i)) +#endif +/** @endcond */ + +#endif /* RUBY3_ARITHMETIC_LONG_H */ |