blob: 1c4c518345ff8fe5e758c7a99363b2632ee6e37e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
|
require File.expand_path('../../../spec_helper', __FILE__)
describe "Bignum#bit_length" do
it "returns the position of the leftmost bit of a positive number" do
(2**1000-1).bit_length.should == 1000
(2**1000).bit_length.should == 1001
(2**1000+1).bit_length.should == 1001
(2**10000-1).bit_length.should == 10000
(2**10000).bit_length.should == 10001
(2**10000+1).bit_length.should == 10001
(1 << 100).bit_length.should == 101
(1 << 100).succ.bit_length.should == 101
(1 << 100).pred.bit_length.should == 100
(1 << 10000).bit_length.should == 10001
end
it "returns the position of the leftmost 0 bit of a negative number" do
(-2**10000-1).bit_length.should == 10001
(-2**10000).bit_length.should == 10000
(-2**10000+1).bit_length.should == 10000
(-2**1000-1).bit_length.should == 1001
(-2**1000).bit_length.should == 1000
(-2**1000+1).bit_length.should == 1000
((-1 << 100)-1).bit_length.should == 101
((-1 << 100)-1).succ.bit_length.should == 100
((-1 << 100)-1).pred.bit_length.should == 101
((-1 << 10000)-1).bit_length.should == 10001
end
end
|
