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-rw-r--r--src/common/CMakeLists.txt2
-rw-r--r--src/common/uint128.cpp41
-rw-r--r--src/common/uint128.h14
3 files changed, 57 insertions, 0 deletions
diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 3d30f0e3e..c538c6415 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -114,6 +114,8 @@ add_library(common STATIC
threadsafe_queue.h
timer.cpp
timer.h
+ uint128.cpp
+ uint128.h
vector_math.h
web_result.h
)
diff --git a/src/common/uint128.cpp b/src/common/uint128.cpp
new file mode 100644
index 000000000..2238a52c5
--- /dev/null
+++ b/src/common/uint128.cpp
@@ -0,0 +1,41 @@
+#ifdef _MSC_VER
+#include <intrin.h>
+
+#pragma intrinsic(_umul128)
+#endif
+#include <cstring>
+#include "common/uint128.h"
+
+namespace Common {
+
+u128 Multiply64Into128(u64 a, u64 b) {
+ u128 result;
+#ifdef _MSC_VER
+ result[0] = _umul128(a, b, &result[1]);
+#else
+ unsigned __int128 tmp = a;
+ tmp *= b;
+ std::memcpy(&result, &tmp, sizeof(u128));
+#endif
+ return result;
+}
+
+std::pair<u64, u64> Divide128On32(u128 dividend, u32 divisor) {
+ u64 remainder = dividend[0] % divisor;
+ u64 accum = dividend[0] / divisor;
+ if (dividend[1] == 0)
+ return {accum, remainder};
+ // We ignore dividend[1] / divisor as that overflows
+ const u64 first_segment = (dividend[1] % divisor) << 32;
+ accum += (first_segment / divisor) << 32;
+ const u64 second_segment = (first_segment % divisor) << 32;
+ accum += (second_segment / divisor);
+ remainder += second_segment % divisor;
+ if (remainder >= divisor) {
+ accum++;
+ remainder -= divisor;
+ }
+ return {accum, remainder};
+}
+
+} // namespace Common
diff --git a/src/common/uint128.h b/src/common/uint128.h
new file mode 100644
index 000000000..52e6b46eb
--- /dev/null
+++ b/src/common/uint128.h
@@ -0,0 +1,14 @@
+
+#include <utility>
+#include "common/common_types.h"
+
+namespace Common {
+
+// This function multiplies 2 u64 values and produces a u128 value;
+u128 Multiply64Into128(u64 a, u64 b);
+
+// This function divides a u128 by a u32 value and produces two u64 values:
+// the result of division and the remainder
+std::pair<u64, u64> Divide128On32(u128 dividend, u32 divisor);
+
+} // namespace Common