ruby--ruby/test/-ext-/bignum/test_pack.rb

# coding: ASCII-8BIT
# frozen_string_literal: false

require 'test/unit'
require "-test-/bignum"

class TestBignum_Pack < Test::Unit::TestCase

  MSWORD_FIRST = Bug::Bignum::INTEGER_PACK_MSWORD_FIRST
  LSWORD_FIRST = Bug::Bignum::INTEGER_PACK_LSWORD_FIRST
  MSBYTE_FIRST = Bug::Bignum::INTEGER_PACK_MSBYTE_FIRST
  LSBYTE_FIRST = Bug::Bignum::INTEGER_PACK_LSBYTE_FIRST
  NATIVE_BYTE_ORDER = Bug::Bignum::INTEGER_PACK_NATIVE_BYTE_ORDER
  TWOCOMP = Bug::Bignum::INTEGER_PACK_2COMP
  LITTLE_ENDIAN = Bug::Bignum::INTEGER_PACK_LITTLE_ENDIAN
  BIG_ENDIAN = Bug::Bignum::INTEGER_PACK_BIG_ENDIAN
  NEGATIVE = Bug::Bignum::INTEGER_PACK_NEGATIVE
  GENERIC = Bug::Bignum::INTEGER_PACK_FORCE_GENERIC_IMPLEMENTATION

  def test_pack_zero
    assert_equal([0, ""], Bug::Bignum.test_pack(0, 0, 1, 0, BIG_ENDIAN))
  end

  def test_pack_argument_check
    assert_raise(ArgumentError) { Bug::Bignum.test_pack_raw(0, "", 2, 1, 0, MSBYTE_FIRST) }
    assert_raise(ArgumentError) { Bug::Bignum.test_pack_raw(0, "", 0, 1, 0, MSWORD_FIRST) }
    assert_raise(ArgumentError) { Bug::Bignum.test_pack_raw(0, "", 0, 0, 0, BIG_ENDIAN) }
    assert_raise(ArgumentError) { Bug::Bignum.test_pack_raw(0, "", 0, 1, 8, BIG_ENDIAN) }

    # assume sizeof(ssize_t) == sizeof(intptr_t)
    assert_raise(ArgumentError) { Bug::Bignum.test_pack_raw(0, "", 1 << ([""].pack("p").length * 8 - 1), 0, BIG_ENDIAN) }
  end

  def test_pack_wordsize
    assert_equal([1, "\x01"], Bug::Bignum.test_pack(1, 1, 1, 0, BIG_ENDIAN))
    assert_equal([1, "\x00\x01"], Bug::Bignum.test_pack(1, 1, 2, 0, BIG_ENDIAN))
    assert_equal([1, "\x00\x00\x01"], Bug::Bignum.test_pack(1, 1, 3, 0, BIG_ENDIAN))
    assert_equal([1, "\x01"], Bug::Bignum.test_pack(1, 1, 1, 0, LITTLE_ENDIAN))
    assert_equal([1, "\x01\x00"], Bug::Bignum.test_pack(1, 1, 2, 0, LITTLE_ENDIAN))
    assert_equal([1, "\x01\x00\x00"], Bug::Bignum.test_pack(1, 1, 3, 0, LITTLE_ENDIAN))
  end

  def test_pack_fixed_buffer
    assert_equal([0, "\x00\x00"], Bug::Bignum.test_pack(0, 2, 1, 0, BIG_ENDIAN))
    assert_equal([1, "\x00\x01"], Bug::Bignum.test_pack(0x01, 2, 1, 0, BIG_ENDIAN))
    assert_equal([1, "\x02\x01"], Bug::Bignum.test_pack(0x0201, 2, 1, 0, BIG_ENDIAN))
    assert_equal([2, "\x02\x01"], Bug::Bignum.test_pack(0x030201, 2, 1, 0, BIG_ENDIAN))
    assert_equal([2, "\x02\x01"], Bug::Bignum.test_pack(0x04030201, 2, 1, 0, BIG_ENDIAN))
    assert_equal([0, "\x00\x00"], Bug::Bignum.test_pack(0, 2, 1, 0, LITTLE_ENDIAN))
    assert_equal([1, "\x01\x00"], Bug::Bignum.test_pack(0x01, 2, 1, 0, LITTLE_ENDIAN))
    assert_equal([1, "\x01\x02"], Bug::Bignum.test_pack(0x0201, 2, 1, 0, LITTLE_ENDIAN))
    assert_equal([2, "\x01\x02"], Bug::Bignum.test_pack(0x030201, 2, 1, 0, LITTLE_ENDIAN))
    assert_equal([2, "\x01\x02"], Bug::Bignum.test_pack(0x04030201, 2, 1, 0, LITTLE_ENDIAN))
  end

  def test_pack_wordorder_and_endian
    assert_equal([1, "\x12\x34\x56\x78"], Bug::Bignum.test_pack(0x12345678, 2, 2, 0, MSWORD_FIRST|MSBYTE_FIRST))
    assert_equal([1, "\x34\x12\x78\x56"], Bug::Bignum.test_pack(0x12345678, 2, 2, 0, MSWORD_FIRST|LSBYTE_FIRST))
    assert_equal([1, "\x56\x78\x12\x34"], Bug::Bignum.test_pack(0x12345678, 2, 2, 0, LSWORD_FIRST|MSBYTE_FIRST))
    assert_equal([1, "\x78\x56\x34\x12"], Bug::Bignum.test_pack(0x12345678, 2, 2, 0, LSWORD_FIRST|LSBYTE_FIRST))
  end

  def test_pack_native_endian
    assert_equal([1, [0x1234].pack("S!")], Bug::Bignum.test_pack(0x1234, 1, 2, 0, MSWORD_FIRST|NATIVE_BYTE_ORDER))
  end

  def test_pack_nail
    assert_equal([1, "\x01\x00\x00\x00\x01\x01"], Bug::Bignum.test_pack(0b100011, 6, 1, 7, BIG_ENDIAN))
    assert_equal([1, "\x01\x02\x03\x04\x05\x06\x07\x08"], Bug::Bignum.test_pack(0x12345678, 8, 1, 4, BIG_ENDIAN))
    assert_equal([1, "\x00\x12\x00\x34\x00\x56\x00\x78"], Bug::Bignum.test_pack(0x12345678, 4, 2, 8, BIG_ENDIAN))
  end

  def test_pack_overflow
    assert_equal([-2, "\x1"], Bug::Bignum.test_pack((-0x11), 1, 1, 4, BIG_ENDIAN))
    assert_equal([-2, "\x0"], Bug::Bignum.test_pack((-0x10), 1, 1, 4, BIG_ENDIAN))
    assert_equal([-1, "\xF"], Bug::Bignum.test_pack((-0x0F), 1, 1, 4, BIG_ENDIAN))
    assert_equal([+1, "\xF"], Bug::Bignum.test_pack((+0x0F), 1, 1, 4, BIG_ENDIAN))
    assert_equal([+2, "\x0"], Bug::Bignum.test_pack((+0x10), 1, 1, 4, BIG_ENDIAN))
    assert_equal([+2, "\x1"], Bug::Bignum.test_pack((+0x11), 1, 1, 4, BIG_ENDIAN))

    assert_equal([-2, "\x01"], Bug::Bignum.test_pack((-0x101), 1, 1, 0, BIG_ENDIAN))
    assert_equal([-2, "\x00"], Bug::Bignum.test_pack((-0x100), 1, 1, 0, BIG_ENDIAN))
    assert_equal([-1, "\xFF"], Bug::Bignum.test_pack((-0x0FF), 1, 1, 0, BIG_ENDIAN))
    assert_equal([+1, "\xFF"], Bug::Bignum.test_pack((+0x0FF), 1, 1, 0, BIG_ENDIAN))
    assert_equal([+2, "\x00"], Bug::Bignum.test_pack((+0x100), 1, 1, 0, BIG_ENDIAN))
    assert_equal([+2, "\x01"], Bug::Bignum.test_pack((+0x101), 1, 1, 0, BIG_ENDIAN))

    assert_equal([-2, "\x00\x00\x00\x00\x00\x00\x00\x01"], Bug::Bignum.test_pack((-0x10000000000000001), 2, 4, 0, BIG_ENDIAN))
    assert_equal([-2, "\x00\x00\x00\x00\x00\x00\x00\x00"], Bug::Bignum.test_pack((-0x10000000000000000), 2, 4, 0, BIG_ENDIAN))
    assert_equal([-1, "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"], Bug::Bignum.test_pack((-0x0FFFFFFFFFFFFFFFF), 2, 4, 0, BIG_ENDIAN))
    assert_equal([+1, "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"], Bug::Bignum.test_pack((+0x0FFFFFFFFFFFFFFFF), 2, 4, 0, BIG_ENDIAN))
    assert_equal([+2, "\x00\x00\x00\x00\x00\x00\x00\x00"], Bug::Bignum.test_pack((+0x10000000000000000), 2, 4, 0, BIG_ENDIAN))
    assert_equal([+2, "\x00\x00\x00\x00\x00\x00\x00\x01"], Bug::Bignum.test_pack((+0x10000000000000001), 2, 4, 0, BIG_ENDIAN))

    1.upto(16) {|wordsize|
      1.upto(20) {|numwords|
        w = numwords*wordsize
        n = 256**w
        assert_equal([-2, "\x00"*(w-1)+"\x01"], Bug::Bignum.test_pack((-n-1), numwords, wordsize, 0, BIG_ENDIAN))
        assert_equal([-2, "\x00"*w],            Bug::Bignum.test_pack((-n  ), numwords, wordsize, 0, BIG_ENDIAN))
        assert_equal([-1, "\xFF"*w],            Bug::Bignum.test_pack((-n+1), numwords, wordsize, 0, BIG_ENDIAN))
        assert_equal([+1, "\xFF"*w],            Bug::Bignum.test_pack((+n-1), numwords, wordsize, 0, BIG_ENDIAN))
        assert_equal([+2, "\x00"*w],            Bug::Bignum.test_pack((+n  ), numwords, wordsize, 0, BIG_ENDIAN))
        assert_equal([+2, "\x00"*(w-1)+"\x01"], Bug::Bignum.test_pack((+n+1), numwords, wordsize, 0, BIG_ENDIAN))
      }
    }

    1.upto(16) {|wordsize|
      1.upto(20) {|numwords|
        w = numwords*wordsize
        n = 256**w
        assert_equal([-2, "\x01"+"\x00"*(w-1)], Bug::Bignum.test_pack((-n-1), numwords, wordsize, 0, LITTLE_ENDIAN))
        assert_equal([-2, "\x00"*w],            Bug::Bignum.test_pack((-n  ), numwords, wordsize, 0, LITTLE_ENDIAN))
        assert_equal([-1, "\xFF"*w],            Bug::Bignum.test_pack((-n+1), numwords, wordsize, 0, LITTLE_ENDIAN))
        assert_equal([+1, "\xFF"*w],            Bug::Bignum.test_pack((+n-1), numwords, wordsize, 0, LITTLE_ENDIAN))
        assert_equal([+2, "\x00"*w],            Bug::Bignum.test_pack((+n  ), numwords, wordsize, 0, LITTLE_ENDIAN))
        assert_equal([+2, "\x01"+"\x00"*(w-1)], Bug::Bignum.test_pack((+n+1), numwords, wordsize, 0, LITTLE_ENDIAN))
      }
    }
  end

  def test_pack_sign
    assert_equal([-1, "\x01"], Bug::Bignum.test_pack((-1), 1, 1, 0, BIG_ENDIAN))
    assert_equal([-1, "\x80\x70\x60\x50\x40\x30\x20\x10"], Bug::Bignum.test_pack((-0x8070605040302010), 8, 1, 0, BIG_ENDIAN))
  end

  def test_pack_orders
    [MSWORD_FIRST, LSWORD_FIRST].each {|word_order|
      [MSBYTE_FIRST, LSBYTE_FIRST, NATIVE_BYTE_ORDER].each {|byte_order|
        1.upto(16) {|wordsize|
          1.upto(20) {|numwords|
            w = numwords*wordsize
            n = 0;
            0.upto(w) {|i|
              n |= ((i+1) % 256) << (i*8)
            }
            assert_equal(Bug::Bignum.test_pack(n, numwords, wordsize, 0, word_order|byte_order|GENERIC),
                         Bug::Bignum.test_pack(n, numwords, wordsize, 0, word_order|byte_order),
                        "#{'%#x' % n}.test_pack(#{numwords}, #{wordsize}, 0, #{'%#x' % (word_order|byte_order)})")
          }
        }
      }
    }
  end

  def test_pack2comp_zero
    assert_equal([0, ""], Bug::Bignum.test_pack(0, 0, 1, 0, TWOCOMP|BIG_ENDIAN))
  end

  def test_pack2comp_emptybuf
    assert_equal([-2, ""], Bug::Bignum.test_pack((-3), 0, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([-2, ""], Bug::Bignum.test_pack((-2), 0, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, ""], Bug::Bignum.test_pack((-1), 0, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([ 0, ""], Bug::Bignum.test_pack(0, 0, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, ""], Bug::Bignum.test_pack(1, 0, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, ""], Bug::Bignum.test_pack(2, 0, 1, 0, TWOCOMP|BIG_ENDIAN))
  end

  def test_pack2comp_nearly_zero
    assert_equal([-1, "\xFE"], Bug::Bignum.test_pack((-2), 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, "\xFF"], Bug::Bignum.test_pack((-1), 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([ 0, "\x00"], Bug::Bignum.test_pack(0, 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+1, "\x01"], Bug::Bignum.test_pack(1, 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+1, "\x02"], Bug::Bignum.test_pack(2, 1, 1, 0, TWOCOMP|BIG_ENDIAN))
  end

  def test_pack2comp_overflow
    assert_equal([-2, "\xF"], Bug::Bignum.test_pack((-0x11), 1, 1, 4, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, "\x0"], Bug::Bignum.test_pack((-0x10), 1, 1, 4, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, "\x1"], Bug::Bignum.test_pack((-0x0F), 1, 1, 4, TWOCOMP|BIG_ENDIAN))
    assert_equal([+1, "\xF"], Bug::Bignum.test_pack((+0x0F), 1, 1, 4, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, "\x0"], Bug::Bignum.test_pack((+0x10), 1, 1, 4, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, "\x1"], Bug::Bignum.test_pack((+0x11), 1, 1, 4, TWOCOMP|BIG_ENDIAN))

    assert_equal([-2, "\xFF"], Bug::Bignum.test_pack((-0x101), 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, "\x00"], Bug::Bignum.test_pack((-0x100), 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, "\x01"], Bug::Bignum.test_pack((-0x0FF), 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+1, "\xFF"], Bug::Bignum.test_pack((+0x0FF), 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, "\x00"], Bug::Bignum.test_pack((+0x100), 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, "\x01"], Bug::Bignum.test_pack((+0x101), 1, 1, 0, TWOCOMP|BIG_ENDIAN))

    assert_equal([-2, "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"], Bug::Bignum.test_pack((-0x10000000000000001), 2, 4, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, "\x00\x00\x00\x00\x00\x00\x00\x00"], Bug::Bignum.test_pack((-0x10000000000000000), 2, 4, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([-1, "\x00\x00\x00\x00\x00\x00\x00\x01"], Bug::Bignum.test_pack((-0x0FFFFFFFFFFFFFFFF), 2, 4, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+1, "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"], Bug::Bignum.test_pack((+0x0FFFFFFFFFFFFFFFF), 2, 4, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, "\x00\x00\x00\x00\x00\x00\x00\x00"], Bug::Bignum.test_pack((+0x10000000000000000), 2, 4, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal([+2, "\x00\x00\x00\x00\x00\x00\x00\x01"], Bug::Bignum.test_pack((+0x10000000000000001), 2, 4, 0, TWOCOMP|BIG_ENDIAN))

    1.upto(16) {|wordsize|
      1.upto(20) {|numwords|
        w = numwords*wordsize
        n = 256**w
        assert_equal([-2, "\xFF"*w           ], Bug::Bignum.test_pack((-n-1), numwords, wordsize, 0, TWOCOMP|BIG_ENDIAN))
        assert_equal([-1, "\x00"*w],            Bug::Bignum.test_pack((-n  ), numwords, wordsize, 0, TWOCOMP|BIG_ENDIAN))
        assert_equal([-1, "\x00"*(w-1)+"\x01"], Bug::Bignum.test_pack((-n+1), numwords, wordsize, 0, TWOCOMP|BIG_ENDIAN))
        assert_equal([+1, "\xFF"*w],            Bug::Bignum.test_pack((+n-1), numwords, wordsize, 0, TWOCOMP|BIG_ENDIAN))
        assert_equal([+2, "\x00"*w],            Bug::Bignum.test_pack((+n  ), numwords, wordsize, 0, TWOCOMP|BIG_ENDIAN))
        assert_equal([+2, "\x00"*(w-1)+"\x01"], Bug::Bignum.test_pack((+n+1), numwords, wordsize, 0, TWOCOMP|BIG_ENDIAN))
      }
    }

    1.upto(16) {|wordsize|
      1.upto(20) {|numwords|
        w = numwords*wordsize
        n = 256**w
        assert_equal([-2, "\xFF"*w           ], Bug::Bignum.test_pack((-n-1), numwords, wordsize, 0, TWOCOMP|LITTLE_ENDIAN))
        assert_equal([-1, "\x00"*w],            Bug::Bignum.test_pack((-n  ), numwords, wordsize, 0, TWOCOMP|LITTLE_ENDIAN))
        assert_equal([-1, "\x01"+"\x00"*(w-1)], Bug::Bignum.test_pack((-n+1), numwords, wordsize, 0, TWOCOMP|LITTLE_ENDIAN))
        assert_equal([+1, "\xFF"*w],            Bug::Bignum.test_pack((+n-1), numwords, wordsize, 0, TWOCOMP|LITTLE_ENDIAN))
        assert_equal([+2, "\x00"*w],            Bug::Bignum.test_pack((+n  ), numwords, wordsize, 0, TWOCOMP|LITTLE_ENDIAN))
        assert_equal([+2, "\x01"+"\x00"*(w-1)], Bug::Bignum.test_pack((+n+1), numwords, wordsize, 0, TWOCOMP|LITTLE_ENDIAN))
      }
    }

    2.upto(16) {|wordsize|
      w = wordsize
      b = 8*wordsize-1
      n = 2**b
      assert_equal([-2, "\x7F"+"\xFF"*(w-2)+"\xFF"], Bug::Bignum.test_pack((-n-1), 1, wordsize, 1, TWOCOMP|MSBYTE_FIRST))
      assert_equal([-1, "\x00"+"\x00"*(w-2)+"\x00"], Bug::Bignum.test_pack((-n  ), 1, wordsize, 1, TWOCOMP|MSBYTE_FIRST))
      assert_equal([-1, "\x00"+"\x00"*(w-2)+"\x01"], Bug::Bignum.test_pack((-n+1), 1, wordsize, 1, TWOCOMP|MSBYTE_FIRST))
      assert_equal([+1, "\x7F"+"\xFF"*(w-2)+"\xFF"], Bug::Bignum.test_pack((+n-1), 1, wordsize, 1, TWOCOMP|MSBYTE_FIRST))
      assert_equal([+2, "\x00"+"\x00"*(w-2)+"\x00"], Bug::Bignum.test_pack((+n  ), 1, wordsize, 1, TWOCOMP|MSBYTE_FIRST))
      assert_equal([+2, "\x00"+"\x00"*(w-2)+"\x01"], Bug::Bignum.test_pack((+n+1), 1, wordsize, 1, TWOCOMP|MSBYTE_FIRST))
    }

    2.upto(16) {|wordsize|
      w = wordsize
      b = 8*wordsize-1
      n = 2**b
      assert_equal([-2, "\xFF"+"\xFF"*(w-2)+"\x7F"], Bug::Bignum.test_pack((-n-1), 1, wordsize, 1, TWOCOMP|LSBYTE_FIRST))
      assert_equal([-1, "\x00"+"\x00"*(w-2)+"\x00"], Bug::Bignum.test_pack((-n  ), 1, wordsize, 1, TWOCOMP|LSBYTE_FIRST))
      assert_equal([-1, "\x01"+"\x00"*(w-2)+"\x00"], Bug::Bignum.test_pack((-n+1), 1, wordsize, 1, TWOCOMP|LSBYTE_FIRST))
      assert_equal([+1, "\xFF"+"\xFF"*(w-2)+"\x7F"], Bug::Bignum.test_pack((+n-1), 1, wordsize, 1, TWOCOMP|LSBYTE_FIRST))
      assert_equal([+2, "\x00"+"\x00"*(w-2)+"\x00"], Bug::Bignum.test_pack((+n  ), 1, wordsize, 1, TWOCOMP|LSBYTE_FIRST))
      assert_equal([+2, "\x01"+"\x00"*(w-2)+"\x00"], Bug::Bignum.test_pack((+n+1), 1, wordsize, 1, TWOCOMP|LSBYTE_FIRST))
    }

  end

  def test_unpack_zero
    assert_equal(0, Bug::Bignum.test_unpack("", 0, 1, 0, BIG_ENDIAN))
  end

  def test_unpack_argument_check
    assert_raise(ArgumentError) { Bug::Bignum.test_unpack("x", 2, 1, 0, MSBYTE_FIRST) }
    assert_raise(ArgumentError) { Bug::Bignum.test_unpack("x", 1, 1, 0, MSWORD_FIRST) }
    assert_raise(ArgumentError) { Bug::Bignum.test_unpack("x", 1, 0, 0, BIG_ENDIAN) }
    assert_raise(ArgumentError) { Bug::Bignum.test_unpack("x", 1, 1, 8, BIG_ENDIAN) }

    # assume sizeof(ssize_t) == sizeof(intptr_t)
    assert_raise(ArgumentError) { Bug::Bignum.test_unpack("x", 1, 1 << ([""].pack("p").length * 8 - 1), 0, BIG_ENDIAN) }
  end

  def test_unpack_wordsize
    assert_equal(1, Bug::Bignum.test_unpack("\x01", 1, 1, 0, BIG_ENDIAN))
    assert_equal(1, Bug::Bignum.test_unpack("\x00\x01", 1, 2, 0, BIG_ENDIAN))
    assert_equal(1, Bug::Bignum.test_unpack("\x00\x00\x01", 1, 3, 0, BIG_ENDIAN))
    assert_equal(1, Bug::Bignum.test_unpack("\x01", 1, 1, 0, LITTLE_ENDIAN))
    assert_equal(1, Bug::Bignum.test_unpack("\x01\x00", 1, 2, 0, LITTLE_ENDIAN))
    assert_equal(1, Bug::Bignum.test_unpack("\x01\x00\x00", 1, 3, 0, LITTLE_ENDIAN))
  end

  def test_unpack_wordorder_and_endian
    assert_equal(0x01020304, Bug::Bignum.test_unpack("\x01\x02\x03\x04", 2, 2, 0, MSWORD_FIRST|MSBYTE_FIRST))
    assert_equal(0x02010403, Bug::Bignum.test_unpack("\x01\x02\x03\x04", 2, 2, 0, MSWORD_FIRST|LSBYTE_FIRST))
    assert_equal(0x03040102, Bug::Bignum.test_unpack("\x01\x02\x03\x04", 2, 2, 0, LSWORD_FIRST|MSBYTE_FIRST))
    assert_equal(0x04030201, Bug::Bignum.test_unpack("\x01\x02\x03\x04", 2, 2, 0, LSWORD_FIRST|LSBYTE_FIRST))
  end

  def test_unpack_native_endian
    assert_equal("\x12\x34".unpack("S!")[0], Bug::Bignum.test_unpack("\x12\x34", 1, 2, 0, MSWORD_FIRST|NATIVE_BYTE_ORDER))
  end

  def test_unpack_nail
    assert_equal(0b100011, Bug::Bignum.test_unpack("\x01\x00\x00\x00\x01\x01", 6, 1, 7, BIG_ENDIAN))
    assert_equal(0x12345678, Bug::Bignum.test_unpack("\x01\x02\x03\x04\x05\x06\x07\x08", 8, 1, 4, BIG_ENDIAN))
    assert_equal(0x12345678, Bug::Bignum.test_unpack("\x00\x12\x00\x34\x00\x56\x00\x78", 4, 2, 8, BIG_ENDIAN))
  end

  def test_unpack_sign
    assert_equal(-1, Bug::Bignum.test_unpack("\x01", 1, 1, 0, BIG_ENDIAN|NEGATIVE))
    assert_equal(-0x8070605040302010, Bug::Bignum.test_unpack("\x80\x70\x60\x50\x40\x30\x20\x10", 8, 1, 0, BIG_ENDIAN|NEGATIVE))
  end

  def test_unpack_orders
    [MSWORD_FIRST, LSWORD_FIRST].each {|word_order|
      [MSBYTE_FIRST, LSBYTE_FIRST, NATIVE_BYTE_ORDER].each {|byte_order|
        1.upto(16) {|wordsize|
          1.upto(20) {|numwords|
            w = numwords*wordsize
            ary = []
            0.upto(w) {|i|
              ary << ((i+1) % 256);
            }
            str = ary.pack("C*")
            flags = word_order|byte_order
            assert_equal(Bug::Bignum.test_unpack(str, numwords, wordsize, 0, flags|GENERIC),
                         Bug::Bignum.test_unpack(str, numwords, wordsize, 0, flags),
                        "Bug::Bignum.test_unpack(#{str.dump}, #{numwords}, #{wordsize}, 0, #{'%#x' % flags})")
          }
        }
      }
    }
  end

  def test_unpack2comp_single_byte
    assert_equal(-128, Bug::Bignum.test_unpack("\x80", 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(  -2, Bug::Bignum.test_unpack("\xFE", 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(  -1, Bug::Bignum.test_unpack("\xFF", 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(   0, Bug::Bignum.test_unpack("\x00", 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(   1, Bug::Bignum.test_unpack("\x01", 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(   2, Bug::Bignum.test_unpack("\x02", 1, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal( 127, Bug::Bignum.test_unpack("\x7F", 1, 1, 0, TWOCOMP|BIG_ENDIAN))
  end

  def test_unpack2comp_sequence_of_ff
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*2, 2, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*3, 3, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*4, 4, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*5, 5, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*6, 6, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*7, 7, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*8, 8, 1, 0, TWOCOMP|BIG_ENDIAN))
    assert_equal(-1, Bug::Bignum.test_unpack("\xFF"*9, 9, 1, 0, TWOCOMP|BIG_ENDIAN))
  end

  def test_unpack2comp_negative_single_byte
    assert_equal(-256, Bug::Bignum.test_unpack("\x00", 1, 1, 0, TWOCOMP|BIG_ENDIAN|NEGATIVE))
    assert_equal(-255, Bug::Bignum.test_unpack("\x01", 1, 1, 0, TWOCOMP|BIG_ENDIAN|NEGATIVE))
    assert_equal(-254, Bug::Bignum.test_unpack("\x02", 1, 1, 0, TWOCOMP|BIG_ENDIAN|NEGATIVE))
    assert_equal(-129, Bug::Bignum.test_unpack("\x7F", 1, 1, 0, TWOCOMP|BIG_ENDIAN|NEGATIVE))
    assert_equal(-128, Bug::Bignum.test_unpack("\x80", 1, 1, 0, TWOCOMP|BIG_ENDIAN|NEGATIVE))
    assert_equal(  -2, Bug::Bignum.test_unpack("\xFE", 1, 1, 0, TWOCOMP|BIG_ENDIAN|NEGATIVE))
    assert_equal(  -1, Bug::Bignum.test_unpack("\xFF", 1, 1, 0, TWOCOMP|BIG_ENDIAN|NEGATIVE))
  end

  def test_unpack2comp_negative_zero
    0.upto(100) {|n|
      str = "\x00"*n
      flags = TWOCOMP|BIG_ENDIAN|NEGATIVE
      assert_equal(-(256**n), Bug::Bignum.test_unpack(str, n, 1, 0, flags))
      flags = TWOCOMP|LITTLE_ENDIAN|NEGATIVE
      assert_equal(-(256**n), Bug::Bignum.test_unpack(str, n, 1, 0, flags),
                  "Bug::Bignum.test_unpack(#{str.dump}, #{n}, 1, 0, #{'%#x' % flags})")
    }
  end

  def test_numbits_2comp
    assert_equal(4, Bug::Bignum.test_numbits_2comp_without_sign(-9))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(-8))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(-7))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(-6))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(-5))
    assert_equal(2, Bug::Bignum.test_numbits_2comp_without_sign(-4))
    assert_equal(2, Bug::Bignum.test_numbits_2comp_without_sign(-3))
    assert_equal(1, Bug::Bignum.test_numbits_2comp_without_sign(-2))
    assert_equal(0, Bug::Bignum.test_numbits_2comp_without_sign(-1))
    assert_equal(0, Bug::Bignum.test_numbits_2comp_without_sign(0))
    assert_equal(1, Bug::Bignum.test_numbits_2comp_without_sign(1))
    assert_equal(2, Bug::Bignum.test_numbits_2comp_without_sign(2))
    assert_equal(2, Bug::Bignum.test_numbits_2comp_without_sign(3))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(4))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(5))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(6))
    assert_equal(3, Bug::Bignum.test_numbits_2comp_without_sign(7))
    assert_equal(4, Bug::Bignum.test_numbits_2comp_without_sign(8))
    assert_equal(4, Bug::Bignum.test_numbits_2comp_without_sign(9))
  end

  def test_numbytes_2comp
    assert_equal(6, Bug::Bignum.test_numbytes_2comp_with_sign(-0x8000000001))
    assert_equal(5, Bug::Bignum.test_numbytes_2comp_with_sign(-0x8000000000))
    assert_equal(5, Bug::Bignum.test_numbytes_2comp_with_sign(-0x80000001))
    assert_equal(4, Bug::Bignum.test_numbytes_2comp_with_sign(-0x80000000))
    assert_equal(4, Bug::Bignum.test_numbytes_2comp_with_sign(-0x800001))
    assert_equal(3, Bug::Bignum.test_numbytes_2comp_with_sign(-0x800000))
    assert_equal(3, Bug::Bignum.test_numbytes_2comp_with_sign(-0x8001))
    assert_equal(2, Bug::Bignum.test_numbytes_2comp_with_sign(-0x8000))
    assert_equal(2, Bug::Bignum.test_numbytes_2comp_with_sign(-0x81))
    assert_equal(1, Bug::Bignum.test_numbytes_2comp_with_sign(-0x80))
    assert_equal(1, Bug::Bignum.test_numbytes_2comp_with_sign(-1))
    assert_equal(1, Bug::Bignum.test_numbytes_2comp_with_sign(0))
    assert_equal(1, Bug::Bignum.test_numbytes_2comp_with_sign(1))
    assert_equal(1, Bug::Bignum.test_numbytes_2comp_with_sign(0x7f))
    assert_equal(2, Bug::Bignum.test_numbytes_2comp_with_sign(0x80))
    assert_equal(2, Bug::Bignum.test_numbytes_2comp_with_sign(0x7fff))
    assert_equal(3, Bug::Bignum.test_numbytes_2comp_with_sign(0x8000))
    assert_equal(3, Bug::Bignum.test_numbytes_2comp_with_sign(0x7fffff))
    assert_equal(4, Bug::Bignum.test_numbytes_2comp_with_sign(0x800000))
    assert_equal(4, Bug::Bignum.test_numbytes_2comp_with_sign(0x7fffffff))
    assert_equal(5, Bug::Bignum.test_numbytes_2comp_with_sign(0x80000000))
    assert_equal(5, Bug::Bignum.test_numbytes_2comp_with_sign(0x7fffffffff))
    assert_equal(6, Bug::Bignum.test_numbytes_2comp_with_sign(0x8000000000))
  end
end