1 files changed, 53 insertions, 0 deletions
diff --git a/test/-ext-/bignum/test_mul.rb b/test/-ext-/bignum/test_mul.rb
new file mode 100644
index 0000000000..ad3b38febd
--- /dev/null
+++ b/test/-ext-/bignum/test_mul.rb
@@ -0,0 +1,53 @@
+require 'test/unit'
+require "-test-/bignum"
+
+class TestBignum < Test::Unit::TestCase
+  class TestMul < Test::Unit::TestCase
+
+    SIZEOF_BDIGITS = Bignum::SIZEOF_BDIGITS
+    BITSPERDIG = Bignum::BITSPERDIG
+
+    def test_mul_normal
+      x = (1 << BITSPERDIG) | 1
+      y = (1 << BITSPERDIG) | 1
+      z = (1 << (BITSPERDIG*2)) | (2 << BITSPERDIG) | 1
+      assert_equal(z, x.big_mul_normal(y))
+    end
+
+    def test_mul_normal_zero_in_x
+      x = (1 << (2*BITSPERDIG)) | 1
+      y = (1 << BITSPERDIG) | 1
+      z = (1 << (BITSPERDIG*3)) | (1 << (BITSPERDIG*2)) | (1 << BITSPERDIG) | 1
+      assert_equal(z, x.big_mul_normal(y))
+    end
+
+    def test_mul_normal_zero_in_y
+      x = (1 << BITSPERDIG) | 1
+      y = (1 << (2*BITSPERDIG)) | 1
+      z = (1 << (BITSPERDIG*3)) | (1 << (BITSPERDIG*2)) | (1 << BITSPERDIG) | 1
+      assert_equal(z, x.big_mul_normal(y))
+    end
+
+    def test_mul_normal_max_max
+      x = (1 << (2*BITSPERDIG)) - 1
+      y = (1 << (2*BITSPERDIG)) - 1
+      z = (1 << (4*BITSPERDIG)) - (1 << (2*BITSPERDIG+1)) + 1
+      assert_equal(z, x.big_mul_normal(y))
+    end
+
+    def test_mul_balance
+      x = (1 << BITSPERDIG) | 1
+      y = (1 << BITSPERDIG) | 1
+      z = (1 << (BITSPERDIG*2)) | (2 << BITSPERDIG) | 1
+      assert_equal(z, x.big_mul_balance(y))
+    end
+
+    def test_mul_karatsuba
+      x = (1 << BITSPERDIG) | 1
+      y = (1 << BITSPERDIG) | 1
+      z = (1 << (BITSPERDIG*2)) | (2 << BITSPERDIG) | 1
+      assert_equal(z, x.big_mul_karatsuba(y))
+    end
+
+  end
+end