From 4d9a167f56025cfbacc104f30c88731a087726c9 Mon Sep 17 00:00:00 2001
From: Nekotekina <nekotekina@gmail.com>
Date: Sat, 24 Apr 2021 19:05:24 +0300
Subject: [PATCH] u128: add multiplication support (for MSVC)

---
 rpcs3/util/types.hpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/rpcs3/util/types.hpp b/rpcs3/util/types.hpp
index 46469cca3c..35a26f8a2e 100644
--- a/rpcs3/util/types.hpp
+++ b/rpcs3/util/types.hpp
@@ -204,6 +204,7 @@ extern "C"
 	uchar _subborrow_u64(uchar, u64, u64, u64*);
 	u64 __shiftleft128(u64, u64, uchar);
 	u64 __shiftright128(u64, u64, uchar);
+	u64 _umul128(u64, u64, u64*);
 }
 
 // Unsigned 128-bit integer implementation (TODO)
@@ -251,6 +252,13 @@ struct alignas(16) u128
 		return value;
 	}
 
+	constexpr friend u128 operator*(const u128& l, const u128& r)
+	{
+		u128 value = l;
+		value *= r;
+		return value;
+	}
+
 	constexpr u128 operator+() const
 	{
 		return *this;
@@ -365,6 +373,24 @@ struct alignas(16) u128
 		return *this;
 	}
 
+	constexpr u128& operator*=(const u128& r)
+	{
+		const u64 _hi = r.hi * lo + r.lo * hi;
+
+		if (std::is_constant_evaluated())
+		{
+			hi = (lo >> 32) * (r.lo >> 32) + (((lo >> 32) * (r.lo & 0xffffffff)) >> 32) + (((r.lo >> 32) * (lo & 0xffffffff)) >> 32);
+			lo = lo * r.lo;
+		}
+		else
+		{
+			lo = _umul128(lo, r.lo, &hi);
+		}
+
+		hi += _hi;
+		return *this;
+	}
+
 	constexpr u128& operator<<=(const u128& r)
 	{
 		if (std::is_constant_evaluated())