Implement 128 bits Unsigned Integer Multiplication and Division.

1 files changed, 30 insertions, 0 deletions

diff --git a/src/common/uint128.h b/src/common/uint128.h
new file mode 100644
index 000000000..fda313bcc
--- /dev/null
+++ b/src/common/uint128.h
@@ -0,0 +1,30 @@
+#include <array>
+#include <cstdint>
+#include <utility>
+#include <cstring>
+#include "common/common_types.h"
+
+namespace Common {
+
+#ifdef _MSC_VER
+#include <intrin.h>
+
+#pragma intrinsic(_umul128)
+#endif
+
+inline u128 umul128(u64 a, u64 b) {
+#ifdef _MSC_VER
+u128 result;
+result[0] = _umul128(a, b, &result[1]);
+#else
+unsigned __int128 tmp = a;
+tmp *= b;
+u128 result;
+std::memcpy(&result, &tmp, sizeof(u128));
+#endif
+return result;
+}
+
+std::pair<u64, u64> udiv128(u128 dividend, u64 divisor);
+
+} // namespace Common