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-rw-r--r--test/-ext-/bignum/test_mul.rb43
1 files changed, 43 insertions, 0 deletions
diff --git a/test/-ext-/bignum/test_mul.rb b/test/-ext-/bignum/test_mul.rb
index ad3b38febd..539b9cf138 100644
--- a/test/-ext-/bignum/test_mul.rb
+++ b/test/-ext-/bignum/test_mul.rb
@@ -6,6 +6,7 @@ class TestBignum < Test::Unit::TestCase
SIZEOF_BDIGITS = Bignum::SIZEOF_BDIGITS
BITSPERDIG = Bignum::BITSPERDIG
+ BDIGMAX = (1 << BITSPERDIG) - 1
def test_mul_normal
x = (1 << BITSPERDIG) | 1
@@ -49,5 +50,47 @@ class TestBignum < Test::Unit::TestCase
assert_equal(z, x.big_mul_karatsuba(y))
end
+ def test_mul_karatsuba_odd_y
+ x = (1 << BITSPERDIG) | 1
+ y = (1 << (2*BITSPERDIG)) | 1
+ assert_equal(x.big_mul_normal(y), x.big_mul_karatsuba(y))
+ end
+
+ def test_mul_karatsuba_odd_xy
+ x = (1 << (2*BITSPERDIG)) | 1
+ y = (1 << (2*BITSPERDIG)) | 1
+ assert_equal(x.big_mul_normal(y), x.big_mul_karatsuba(y))
+ end
+
+ def test_mul_karatsuba_x1_gt_x0
+ x = (2 << BITSPERDIG) | 1
+ y = (1 << BITSPERDIG) | 2
+ assert_equal(x.big_mul_normal(y), x.big_mul_karatsuba(y))
+ end
+
+ def test_mul_karatsuba_y1_gt_y0
+ x = (1 << BITSPERDIG) | 2
+ y = (2 << BITSPERDIG) | 1
+ assert_equal(x.big_mul_normal(y), x.big_mul_karatsuba(y))
+ end
+
+ def test_mul_karatsuba_x1_gt_x0_and_y1_gt_y0
+ x = (2 << BITSPERDIG) | 1
+ y = (2 << BITSPERDIG) | 1
+ assert_equal(x.big_mul_normal(y), x.big_mul_karatsuba(y))
+ end
+
+ def test_mul_karatsuba_carry2
+ x = (1 << BITSPERDIG) | BDIGMAX
+ y = (1 << BITSPERDIG) | BDIGMAX
+ assert_equal(x.big_mul_normal(y), x.big_mul_karatsuba(y))
+ end
+
+ def test_mul_karatsuba_borrow
+ x = (BDIGMAX << BITSPERDIG) | 1
+ y = (BDIGMAX << BITSPERDIG) | 1
+ assert_equal(x.big_mul_normal(y), x.big_mul_karatsuba(y))
+ end
+
end
end