From dca234a5dc9d5bb39c906d833c43305ce95508fb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?=E5=8D=9C=E9=83=A8=E6=98=8C=E5=B9=B3?= Date: Mon, 4 May 2020 15:26:12 +0900 Subject: mv include/ruby/{3,impl} Devs do not love "3". --- include/ruby/impl/arithmetic/fixnum.h | 44 +++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 include/ruby/impl/arithmetic/fixnum.h (limited to 'include/ruby/impl/arithmetic/fixnum.h') diff --git a/include/ruby/impl/arithmetic/fixnum.h b/include/ruby/impl/arithmetic/fixnum.h new file mode 100644 index 0000000000..d7214e080b --- /dev/null +++ b/include/ruby/impl/arithmetic/fixnum.h @@ -0,0 +1,44 @@ +#ifndef RUBY3_ARITHMETIC_FIXNUM_H /*-*-C++-*-vi:se ft=cpp:*/ +#define RUBY3_ARITHMETIC_FIXNUM_H +/** + * @file + * @author Ruby developers + * @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 Handling of integers formerly known as Fixnums. + */ +#include "ruby/backward/2/limits.h" + +#define FIXABLE RB_FIXABLE +#define FIXNUM_MAX RUBY_FIXNUM_MAX +#define FIXNUM_MIN RUBY_FIXNUM_MIN +#define NEGFIXABLE RB_NEGFIXABLE +#define POSFIXABLE RB_POSFIXABLE + +/* + * FIXABLE can be applied to anything, from double to intmax_t. The problem is + * double. On a 64bit system RUBY_FIXNUM_MAX is 4,611,686,018,427,387,903, + * which is not representable by a double. The nearest value that a double can + * represent is 4,611,686,018,427,387,904, which is not fixable. The + * seemingly-stragne "< FIXNUM_MAX + 1" expression below is due to this. + */ +#define RB_POSFIXABLE(_) ((_) < RUBY_FIXNUM_MAX + 1) +#define RB_NEGFIXABLE(_) ((_) >= RUBY_FIXNUM_MIN) +#define RB_FIXABLE(_) (RB_POSFIXABLE(_) && RB_NEGFIXABLE(_)) +#define RUBY_FIXNUM_MAX (LONG_MAX / 2) +#define RUBY_FIXNUM_MIN (LONG_MIN / 2) + +#endif /* RUBY3_ARITHMETIC_FIXNUM_H */ -- cgit v1.2.3