diff --git a/src/osd/eigccx86.h b/src/osd/eigccx86.h
index b3831d21524..3c8f63aa47e 100644
--- a/src/osd/eigccx86.h
+++ b/src/osd/eigccx86.h
@@ -456,6 +456,40 @@ _recip_approx(float value)
 #endif
 
 
+/*-------------------------------------------------
+    mul_64x64 - perform a signed 64 bit x 64 bit
+    multiply and return the full 128 bit result
+-------------------------------------------------*/
+
+#ifdef __x86_64__
+#define mul_64x64 _mul_64x64
+inline int64_t ATTR_FORCE_INLINE
+_mul_64x64(int64_t a, int64_t b, int64_t *hi)
+{
+	__int128 const r(__int128(a) * b);
+	*hi = int64_t(uint64_t((unsigned __int128)r >> 64));
+	return int64_t(uint64_t((unsigned __int128)r));
+}
+#endif
+
+
+/*-------------------------------------------------
+    mulu_64x64 - perform an unsigned 64 bit x 64
+    bit multiply and return the full 128 bit result
+-------------------------------------------------*/
+
+#ifdef __x86_64__
+#define mulu_64x64 _mulu_64x64
+inline uint64_t ATTR_FORCE_INLINE
+_mulu_64x64(uint64_t a, uint64_t b, uint64_t *hi)
+{
+	unsigned __int128 const r((unsigned __int128)a * b);
+	*hi = uint64_t(r >> 64);
+	return uint64_t(r);
+}
+#endif
+
+
 
 /***************************************************************************
     INLINE BIT MANIPULATION FUNCTIONS
diff --git a/src/osd/eminline.h b/src/osd/eminline.h
index 1f543a21b36..eb8ffaa9748 100644
--- a/src/osd/eminline.h
+++ b/src/osd/eminline.h
@@ -268,10 +268,10 @@ inline float recip_approx(float value)
 #ifndef mul_64x64
 inline int64_t mul_64x64(int64_t a, int64_t b, int64_t *hi)
 {
-	uint64_t const a_hi = uint32_t(a >> 32);
-	uint64_t const b_hi = uint32_t(b >> 32);
-	uint64_t const a_lo = uint32_t(a);
-	uint64_t const b_lo = uint32_t(b);
+	uint64_t const a_hi = uint64_t(a) >> 32;
+	uint64_t const b_hi = uint64_t(b) >> 32;
+	uint64_t const a_lo = uint32_t(uint64_t(a));
+	uint64_t const b_lo = uint32_t(uint64_t(b));
 
 	uint64_t const ab_lo = a_lo * b_lo;
 	uint64_t const ab_m1 = a_hi * b_lo;
@@ -317,6 +317,8 @@ inline uint64_t mulu_64x64(uint64_t a, uint64_t b, uint64_t *hi)
 }
 #endif
 
+
+
 /***************************************************************************
     INLINE BIT MANIPULATION FUNCTIONS
 ***************************************************************************/