diff --git a/3rdparty/softfloat3/build/MAME/platform.h b/3rdparty/softfloat3/build/MAME/platform.h
index 4a2cb42f299..441fdc8d05a 100644
--- a/3rdparty/softfloat3/build/MAME/platform.h
+++ b/3rdparty/softfloat3/build/MAME/platform.h
@@ -54,12 +54,21 @@ Softfloat 3 MAME modifications
 /*----------------------------------------------------------------------------
 *----------------------------------------------------------------------------*/
 
-// may not be true for MSVC?  true for GCC and Clang on Intel and ARM at least.
+// true for GCC and Clang on Intel and ARM, and MSVC on Intel.
 #define SOFTFLOAT_BUILTIN_CLZ 1
 
+#ifdef _MSC_VER
+#define _INC_MALLOC 0
+#include <intrin.h>
+
+// MSVC has __lzcnt16 as well, but opts-GCC.h expects __lzcnt for uint16_t and uint32_t
+#define __builtin_clz __lzcnt
+#define __builtin_clzll __lzcnt64
+#else
 #if defined(PTR64)
 #define SOFTFLOAT_INTRINSIC_INT128 1
 #endif
+#endif
 
 #include "opts-GCC.h"
 
diff --git a/scripts/src/3rdparty.lua b/scripts/src/3rdparty.lua
index 94879049604..7c1cc4acf4c 100644
--- a/scripts/src/3rdparty.lua
+++ b/scripts/src/3rdparty.lua
@@ -196,6 +196,12 @@ includedirs {
 	MAME_DIR .. "3rdparty/softfloat3/source/8086",
 }
 
+configuration { "vs*" }
+buildoptions {
+	"/wd4701", -- warning C4701: potentially uninitialized local variable 'xxx' used
+	"/wd4703", -- warning C4703: potentially uninitialized local pointer variable 'xxx' used
+}
+
 configuration { }
 defines {
 	"SOFTFLOAT_ROUND_ODD",