--- libmalloc/libmalloc-374.60.3/src/platform.h
+++ libmalloc/libmalloc-409.81.2/src/platform.h
@@ -24,11 +24,11 @@
 #ifndef __PLATFORM_H
 #define __PLATFORM_H
 
-#if TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+#if (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) || (TARGET_OS_DRIVERKIT && !MALLOC_TARGET_DK_OSX)
 #define MALLOC_TARGET_IOS 1
-#else // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+#else // (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) || (TARGET_OS_DRIVERKIT && !MALLOC_TARGET_DK_OSX)
 #define MALLOC_TARGET_IOS 0
-#endif // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+#endif // (TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR) || (TARGET_OS_DRIVERKIT && !MALLOC_TARGET_DK_OSX)
 
 #ifdef __LP64__
 #define MALLOC_TARGET_64BIT 1
@@ -96,15 +96,33 @@
 #endif // MALLOC_TARGET_64BIT
 
 // The large last-free cache (aka. death row cache)
-#if MALLOC_TARGET_IOS
+#if TARGET_OS_IOS || TARGET_OS_SIMULATOR || TARGET_OS_DRIVERKIT
+// sdk=iphoneos, simulator, sdk=driverkit
+#define CONFIG_LARGE_CACHE 1
+#elif MALLOC_TARGET_IOS
+// all other embedded
 #define CONFIG_LARGE_CACHE 0
 #else
+// Mac
 #define CONFIG_LARGE_CACHE 1
 #endif
 
 #if CONFIG_LARGE_CACHE
+
+#if MALLOC_TARGET_IOS && MALLOC_TARGET_64BIT
+#define DEFAULT_LARGE_CACHE_ENABLED false
+#define CONFIG_DEFERRED_RECLAIM 1
+
+#elif TARGET_OS_SIMULATOR || (MALLOC_TARGET_IOS && !MALLOC_TARGET_64BIT)
+#define DEFAULT_LARGE_CACHE_ENABLED false
+#define CONFIG_DEFERRED_RECLAIM 0
+
+#else // TARGET_OS_SIMULATOR || (MALLOC_TARGET_IOS && !MALLOC_TARGET_64BIT)
 #define DEFAULT_LARGE_CACHE_ENABLED true
-#endif
+#define CONFIG_DEFERRED_RECLAIM 0
+
+#endif // TARGET_OS_SIMULATOR || (MALLOC_TARGET_IOS && !MALLOC_TARGET_64BIT)
+#endif // CONFIG_LARGE_CACHE
 
 #if MALLOC_TARGET_IOS
 // The VM system on iOS forces malloc-tagged memory to never be marked as
@@ -146,4 +164,16 @@
 #define CONFIG_TINY_USES_HYPER_SHIFT 0
 #define CONFIG_SMALL_USES_HYPER_SHIFT 0
 
+// FIXME: limit number of malloc_create_zone() wrapper zones for watchOS to remove this
+#if TARGET_OS_OSX || TARGET_OS_IOS
+#define CONFIG_PGM_WRAP_CUSTOM_ZONES 1
+#else
+#define CONFIG_PGM_WRAP_CUSTOM_ZONES 0
+#endif
+
+
+#ifndef MALLOC_ZERO_POLICY_DEFAULT
+#define MALLOC_ZERO_POLICY_DEFAULT MALLOC_ZERO_ON_FREE
+#endif
+
 #endif // __PLATFORM_H