#include <limits.h> #include "ruby.h" int signbit(double x) { enum {double_per_long = sizeof(double) / sizeof(long)}; enum {long_msb = sizeof(long) * CHAR_BIT - 1}; union {double d; unsigned long i[double_per_long];} u; unsigned long l; u.d = x; #ifdef WORDS_BIGENDIAN l = u.i[0]; #else l = u.i[double_per_long - 1]; #endif return (int)(l >> long_msb); }