--- libmalloc/libmalloc-140.40.1/src/platform.h
+++ libmalloc/libmalloc-317.40.8/src/platform.h
@@ -24,11 +24,11 @@
 #ifndef __PLATFORM_H
 #define __PLATFORM_H
 
-#if TARGET_OS_EMBEDDED
+#if TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
 #define MALLOC_TARGET_IOS 1
-#else // MALLOC_TARGET_IOS
+#else // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
 #define MALLOC_TARGET_IOS 0
-#endif // MALLOC_TARGET_IOS
+#endif // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
 
 #ifdef __LP64__
 #define MALLOC_TARGET_64BIT 1
@@ -44,12 +44,13 @@
 #endif // MALLOC_TARGET_IOS
 
 // <rdar://problem/12596555>
+#define CONFIG_RECIRC_DEPOT 1
+#define CONFIG_AGGRESSIVE_MADVISE 1
+
 #if MALLOC_TARGET_IOS
-# define CONFIG_RECIRC_DEPOT 0
-# define CONFIG_AGGRESSIVE_MADVISE 1
+# define DEFAULT_AGGRESSIVE_MADVISE_ENABLED true
 #else // MALLOC_TARGET_IOS
-# define CONFIG_RECIRC_DEPOT 1
-# define CONFIG_AGGRESSIVE_MADVISE 0
+# define DEFAULT_AGGRESSIVE_MADVISE_ENABLED false
 #endif // MALLOC_TARGET_IOS
 
 // <rdar://problem/10397726>
@@ -57,15 +58,6 @@
 
 // <rdar://problem/19818071>
 #define CONFIG_MADVISE_STYLE MADV_FREE_REUSABLE
-
-// <rdar://problem/13807682>
-#if TARGET_OS_SIMULATOR
-#define CONFIG_OS_LOCK_HANDOFF 1
-#elif MALLOC_TARGET_IOS
-#define CONFIG_OS_LOCK_UNFAIR 1
-#else // MALLOC_TARGET_IOS
-#define CONFIG_OS_LOCK_UNFAIR 1
-#endif // MALLOC_TARGET_IOS
 
 #if MALLOC_TARGET_64BIT
 #define CONFIG_NANOZONE 1
@@ -81,6 +73,18 @@
 // This governs a last-free cache of 1 that bypasses the free-list for each region size
 #define CONFIG_TINY_CACHE 1
 #define CONFIG_SMALL_CACHE 1
+#define CONFIG_MEDIUM_CACHE 1
+
+// medium allocator enabled or disabled
+#if MALLOC_TARGET_64BIT
+#if MALLOC_TARGET_IOS
+#define CONFIG_MEDIUM_ALLOCATOR 0
+#else // MALLOC_TARGET_IOS
+#define CONFIG_MEDIUM_ALLOCATOR 1
+#endif // MALLOC_TARGET_IOS
+#else // MALLOC_TARGET_64BIT
+#define CONFIG_MEDIUM_ALLOCATOR 0
+#endif // MALLOC_TARGET_64BIT
 
 // The large last-free cache (aka. death row cache)
 #if MALLOC_TARGET_IOS
@@ -89,20 +93,17 @@
 #define CONFIG_LARGE_CACHE 1
 #endif
 
-// <rdar://problem/26823590> compile-time MALLOC_SMALL cut-off size
+#if CONFIG_LARGE_CACHE
+#define DEFAULT_LARGE_CACHE_ENABLED true
+#endif
+
 #if MALLOC_TARGET_IOS
-#define CONFIG_SMALL_CUTTOFF_127KB 0
+// The VM system on iOS forces malloc-tagged memory to never be marked as
+// copy-on-write, this would include calls we make to vm_copy. Given that the
+// kernel would just be doing a memcpy, we force it to happen in userpsace.
+#define CONFIG_REALLOC_CAN_USE_VMCOPY 0
 #else
-#define CONFIG_SMALL_CUTTOFF_127KB 1
-#endif // MALLOC_TARGET_IOS
-
-#if CONFIG_NANOZONE
-// <rdar://problem/35305995>
-#if MALLOC_TARGET_IOS && TARGET_OS_IOS
-#define CONFIG_NANO_SMALLMEM_DYNAMIC_DISABLE_35305995 1
-#else
-#define CONFIG_NANO_SMALLMEM_DYNAMIC_DISABLE_35305995 0
-#endif
+#define CONFIG_REALLOC_CAN_USE_VMCOPY 1
 #endif
 
 // memory resource exception handling
@@ -112,10 +113,21 @@
 #define ENABLE_MEMORY_RESOURCE_EXCEPTION_HANDLING 1
 #endif
 
+#if !TARGET_OS_DRIVERKIT && (!TARGET_OS_OSX || MALLOC_TARGET_64BIT)
+#define CONFIG_FEATUREFLAGS_SIMPLE 1
+#else
+#define CONFIG_FEATUREFLAGS_SIMPLE 0
+#endif
+
 // presence of commpage memsize
 #define CONFIG_HAS_COMMPAGE_MEMSIZE 1
 
 // presence of commpage number of cpu count
 #define CONFIG_HAS_COMMPAGE_NCPUS 1
 
+// Use of hyper-shift for magazine selection.
+#define CONFIG_NANO_USES_HYPER_SHIFT 0
+#define CONFIG_TINY_USES_HYPER_SHIFT 0
+#define CONFIG_SMALL_USES_HYPER_SHIFT 0
+
 #endif // __PLATFORM_H