Index: lib/Transforms/Instrumentation/AddressSanitizer.cpp
===================================================================
--- lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -63,6 +63,15 @@
 
 #define DEBUG_TYPE "asan"
 
+// VMA size definition for architecture that support multiple sizes.
+// AArch64 has 3 VMA sizes: 39, 42 and 48.
+#if SANITIZER_AARCH64_VMA != 39 && SANITIZER_AARCH64_VMA != 42
+# error "invalid SANITIZER_AARCH64_VMA size"
+#endif
+#ifndef SANITIZER_AARCH64_VMA
+# define SANITIZER_AARCH64_VMA 39
+#endif
+
 static const uint64_t kDefaultShadowScale = 3;
 static const uint64_t kDefaultShadowOffset32 = 1ULL << 29;
 static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
@@ -72,7 +81,11 @@
 static const uint64_t kPPC64_ShadowOffset64 = 1ULL << 41;
 static const uint64_t kMIPS32_ShadowOffset32 = 0x0aaa0000;
 static const uint64_t kMIPS64_ShadowOffset64 = 1ULL << 37;
+#if SANITIZER_AARCH64_VMA == 39
 static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 36;
+#elif SANITIZER_AARCH64_VMA == 42
+static const uint64_t kAArch64_ShadowOffset64 = 1ULL << 39;
+#endif
 static const uint64_t kFreeBSD_ShadowOffset32 = 1ULL << 30;
 static const uint64_t kFreeBSD_ShadowOffset64 = 1ULL << 46;
 static const uint64_t kWindowsShadowOffset32 = 3ULL << 28;