Ruby: include/ruby/internal/arithmetic/fixnum.h Source File

Ruby 3.0.5p211 (2022-11-24 revision ba5cf0f7c52d4d35cc6a173c89eda98ceffa2dcf)

fixnum.h
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1#ifndef RBIMPL_ARITHMETIC_FIXNUM_H /*-*-C++-*-vi:se ft=cpp:*/
2#define RBIMPL_ARITHMETIC_FIXNUM_H
23#include "ruby/backward/2/limits.h"
24
25#define FIXABLE RB_FIXABLE
26#define FIXNUM_MAX RUBY_FIXNUM_MAX
27#define FIXNUM_MIN RUBY_FIXNUM_MIN
28#define NEGFIXABLE RB_NEGFIXABLE
29#define POSFIXABLE RB_POSFIXABLE
30
31/*
32 * FIXABLE can be applied to anything, from double to intmax_t. The problem is
33 * double. On a 64bit system RUBY_FIXNUM_MAX is 4,611,686,018,427,387,903,
34 * which is not representable by a double. The nearest value that a double can
35 * represent is 4,611,686,018,427,387,904, which is not fixable. The
36 * seemingly-stragne "< FIXNUM_MAX + 1" expression below is due to this.
37 */
38#define RB_POSFIXABLE(_) ((_) < RUBY_FIXNUM_MAX + 1)
39#define RB_NEGFIXABLE(_) ((_) >= RUBY_FIXNUM_MIN)
40#define RB_FIXABLE(_) (RB_POSFIXABLE(_) && RB_NEGFIXABLE(_))
41#define RUBY_FIXNUM_MAX (LONG_MAX / 2)
42#define RUBY_FIXNUM_MIN (LONG_MIN / 2)
43
44#endif /* RBIMPL_ARITHMETIC_FIXNUM_H */
limits.h
Historical shim for <limits.h>.