diff options
Diffstat (limited to 'numeric.c')
-rw-r--r-- | numeric.c | 39 |
1 files changed, 32 insertions, 7 deletions
@@ -4121,6 +4121,15 @@ fix_size(VALUE fix) return INT2FIX(sizeof(long)); } +static VALUE +rb_fix_bit_length(VALUE fix) +{ + long v = FIX2LONG(fix); + if (v < 0) + v = ~v; + return LONG2FIX(bit_length(v)); +} + /* * call-seq: * int.bit_length -> integer @@ -4133,7 +4142,14 @@ fix_size(VALUE fix) * If there is no such bit (zero or minus one), zero is returned. * * I.e. This method returns ceil(log2(int < 0 ? -int : int+1)). - * + + + * (-2**10000-1).bit_length #=> 10001 + * (-2**10000).bit_length #=> 10000 + * (-2**10000+1).bit_length #=> 10000 + * (-2**1000-1).bit_length #=> 1001 + * (-2**1000).bit_length #=> 1000 + * (-2**1000+1).bit_length #=> 1000 * (-2**12-1).bit_length #=> 13 * (-2**12).bit_length #=> 12 * (-2**12+1).bit_length #=> 12 @@ -4149,6 +4165,12 @@ fix_size(VALUE fix) * (2**12-1).bit_length #=> 12 * (2**12).bit_length #=> 13 * (2**12+1).bit_length #=> 13 + * (2**1000-1).bit_length #=> 1000 + * (2**1000).bit_length #=> 1001 + * (2**1000+1).bit_length #=> 1001 + * (2**10000-1).bit_length #=> 10000 + * (2**10000).bit_length #=> 10001 + * (2**10000+1).bit_length #=> 10001 * * This method can be used to detect overflow in Array#pack as follows. * @@ -4160,12 +4182,15 @@ fix_size(VALUE fix) */ static VALUE -rb_fix_bit_length(VALUE fix) +rb_int_bit_length(VALUE num) { - long v = FIX2LONG(fix); - if (v < 0) - v = ~v; - return LONG2FIX(bit_length(v)); + if (FIXNUM_P(num)) { + return rb_fix_bit_length(num); + } + else if (RB_TYPE_P(num, T_BIGNUM)) { + return rb_big_bit_length(num); + } + return Qnil; } static VALUE @@ -4645,7 +4670,7 @@ Init_Numeric(void) rb_define_method(rb_cFixnum, ">>", rb_fix_rshift, 1); rb_define_method(rb_cFixnum, "size", fix_size, 0); - rb_define_method(rb_cFixnum, "bit_length", rb_fix_bit_length, 0); + rb_define_method(rb_cInteger, "bit_length", rb_int_bit_length, 0); rb_define_method(rb_cFixnum, "succ", fix_succ, 0); rb_cFloat = rb_define_class("Float", rb_cNumeric); |