--- /dev/null
+++ libmalloc/libmalloc-283/src/nano_zone_common.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2018 Apple Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+ 
+#ifndef __NANO_ZONE_COMMON_H
+#define __NANO_ZONE_COMMON_H
+
+#define NANO_MAX_SIZE			256 /* Buckets sized {16, 32, 48, ..., 256} */
+#define SHIFT_NANO_QUANTUM		4
+#define NANO_REGIME_QUANTA_SIZE	(1 << SHIFT_NANO_QUANTUM)	// 16
+#define NANO_QUANTA_MASK		(NANO_REGIME_QUANTA_SIZE - 1)
+#define NANO_SIZE_CLASSES		(NANO_MAX_SIZE/NANO_REGIME_QUANTA_SIZE)
+
+#if TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+
+// Nanozone follows the shared region.
+#define SHIFT_NANO_SIGNATURE	29
+#define NANOZONE_SIGNATURE_BITS	35
+#define NANOZONE_BASE_REGION_ADDRESS (SHARED_REGION_BASE + SHARED_REGION_SIZE)
+#define NANOZONE_SIGNATURE (NANOZONE_BASE_REGION_ADDRESS >> SHIFT_NANO_SIGNATURE)
+
+#else // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+
+#define SHIFT_NANO_SIGNATURE	44
+#define NANOZONE_SIGNATURE_BITS	20
+#define NANOZONE_SIGNATURE		0x6ULL
+#define NANOZONE_BASE_REGION_ADDRESS (NANOZONE_SIGNATURE << SHIFT_NANO_SIGNATURE)
+
+#endif // TARGET_OS_IPHONE && !TARGET_OS_SIMULATOR
+
+static MALLOC_INLINE size_t
+_nano_common_good_size(size_t size)
+{
+	return (size <= NANO_REGIME_QUANTA_SIZE) ? NANO_REGIME_QUANTA_SIZE
+		: (((size + NANO_REGIME_QUANTA_SIZE - 1) >> SHIFT_NANO_QUANTUM) << SHIFT_NANO_QUANTUM);
+}
+
+#endif // __NANO_ZONE_COMMON_H