Index: compiler-rt/lib/asan/asan_allocator.h
===================================================================
--- compiler-rt/lib/asan/asan_allocator.h
+++ compiler-rt/lib/asan/asan_allocator.h
@@ -118,39 +118,244 @@
   void OnUnmap(uptr p, uptr size) const;
 };
 
-#if SANITIZER_CAN_USE_ALLOCATOR64
+#if defined(__aarch64__)
+// AArch64 supports 39, 42 and 48-bit VMA.
+const uptr kAllocatorSpace = ~(uptr)0;
+# if SANITIZER_ANDROID
+const uptr kAllocatorSize  =  0x2000000000ULL;  // 128G.
+typedef VeryCompactSizeClassMap SizeClassMap64;
+# else
+const uptr kAllocatorSize  = 0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap64;
+# endif
+
+template <typename AddressSpaceViewTy>
+struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
+  static const uptr kSpaceBeg = kAllocatorSpace;
+  static const uptr kSpaceSize = kAllocatorSize;
+  static const uptr kMetadataSize = 0;
+  typedef __asan::SizeClassMap64 SizeClassMap;
+  typedef AsanMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+  using AddressSpaceView = AddressSpaceViewTy;
+};
+template <typename AddressSpaceView>
+using Allocator64ASVT = SizeClassAllocator64<AP64<AddressSpaceView>>;
+using Allocator64 = Allocator64ASVT<LocalAddressSpaceView>;
+
+typedef CompactSizeClassMap SizeClassMap32;
+template <typename AddressSpaceViewTy>
+struct AP32 {
+  static const uptr kSpaceBeg = 0;
+  static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+  static const uptr kMetadataSize = 16;
+  typedef __asan::SizeClassMap32 SizeClassMap;
+  static const uptr kRegionSizeLog = 20;
+  using AddressSpaceView = AddressSpaceViewTy;
+  typedef AsanMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+};
+template <typename AddressSpaceView>
+using Allocator32ASVT = SizeClassAllocator32<AP32<AddressSpaceView>>;
+using Allocator32 = Allocator32ASVT<LocalAddressSpaceView>;
+
+extern bool UseAllocator32;
+
+static inline uptr getKNumClasses() {
+  if (UseAllocator32)
+    return SizeClassMap32::kNumClasses;
+  return SizeClassMap64::kNumClasses;
+}
+
+static inline uptr getKMaxSize() {
+  if (UseAllocator32)
+    return SizeClassMap32::kMaxSize;
+  return SizeClassMap64::kMaxSize;
+}
+
+static inline uptr getClassID(uptr size) {
+  if (UseAllocator32)
+    return SizeClassMap32::ClassID(size);
+  return SizeClassMap64::ClassID(size);
+}
+
+static const uptr kMaxNumberOfSizeClasses =
+  SizeClassMap32::kNumClasses < SizeClassMap64::kNumClasses
+        ? SizeClassMap64::kNumClasses
+        : SizeClassMap32::kNumClasses;
+
+
+template <class A32, class A64>
+class DoubleAllocator {
+  A32 a32;
+  A64 a64;
+
+ public:
+  class DoubleAllocatorCache {
+    typename A32::AllocatorCache a32;
+    typename A64::AllocatorCache a64;
+
+   public:
+    void Init(AllocatorGlobalStats *s) {
+      if (UseAllocator32)
+        a32.Init(s);
+      else
+        a64.Init(s);
+    }
+    void *Allocate(DoubleAllocator *allocator, uptr class_id) {
+      if (UseAllocator32)
+        return a32.Allocate(&allocator->a32, class_id);
+      return a64.Allocate(&allocator->a64, class_id);
+    }
+
+    void Deallocate(DoubleAllocator *allocator, uptr class_id, void *p) {
+      if (UseAllocator32)
+        a32.Deallocate(&allocator->a32, class_id, p);
+      else
+        a64.Deallocate(&allocator->a64, class_id, p);
+    }
+
+    void Drain(DoubleAllocator *allocator) {
+      if (UseAllocator32)
+        a32.Drain(&allocator->a32);
+      else
+        a64.Drain(&allocator->a64);
+    }
+
+    void Destroy(DoubleAllocator *allocator, AllocatorGlobalStats *s) {
+      if (UseAllocator32)
+        a32.Destroy(&allocator->a32, s);
+      else
+        a64.Destroy(&allocator->a64, s);
+    }
+  };
+
+  using MapUnmapCallback = Allocator32::MapUnmapCallback;
+  using AddressSpaceView = Allocator32::AddressSpaceView;
+  using AllocatorCache = DoubleAllocatorCache;
+
+  void Init(s32 release_to_os_interval_ms) {
+    if (UseAllocator32)
+      a32.Init(release_to_os_interval_ms);
+    else
+      a64.Init(release_to_os_interval_ms);
+  }
+
+  static bool CanAllocate(uptr size, uptr alignment) {
+    if (UseAllocator32)
+      return A32::CanAllocate(size, alignment);
+    return A64::CanAllocate(size, alignment);
+  }
+
+  static uptr ClassID(uptr size) {
+    if (UseAllocator32)
+      return A32::ClassID(size);
+    return A64::ClassID(size);
+  }
+
+  bool PointerIsMine(const void *p) {
+    if (UseAllocator32)
+      return a32.PointerIsMine(p);
+    return a64.PointerIsMine(p);
+  }
+
+  void *GetMetaData(const void *p) {
+    if (UseAllocator32)
+      return a32.GetMetaData(p);
+    return a64.GetMetaData(p);
+  }
+
+  uptr GetSizeClass(const void *p) {
+    if (UseAllocator32)
+      return a32.GetSizeClass(p);
+    return a64.GetSizeClass(p);
+  }
+
+  void ForEachChunk(ForEachChunkCallback callback, void *arg) {
+    if (UseAllocator32)
+      a32.ForEachChunk(callback, arg);
+    else
+      a64.ForEachChunk(callback, arg);
+  }
+
+  void TestOnlyUnmap() {
+    if (UseAllocator32)
+      a32.TestOnlyUnmap();
+    else
+      a64.TestOnlyUnmap();
+  }
+  void ForceLock() {
+    if (UseAllocator32)
+      a32.ForceLock();
+    else
+      a64.ForceLock();
+  }
+  void ForceUnlock() {
+    if (UseAllocator32)
+      a32.ForceUnlock();
+    else
+      a64.ForceUnlock();
+  }
+  void *GetBlockBegin(const void *p) {
+    if (UseAllocator32)
+      return a32.GetBlockBegin(p);
+    return a64.GetBlockBegin(p);
+  }
+  uptr GetActuallyAllocatedSize(void *p) {
+    if (UseAllocator32)
+      return a32.GetActuallyAllocatedSize(p);
+    return a64.GetActuallyAllocatedSize(p);
+  }
+  void SetReleaseToOSIntervalMs(s32 release_to_os_interval_ms) {
+    if (UseAllocator32)
+      a32.SetReleaseToOSIntervalMs(release_to_os_interval_ms);
+    else
+      a64.SetReleaseToOSIntervalMs(release_to_os_interval_ms);
+  }
+  s32 ReleaseToOSIntervalMs() const {
+    if (UseAllocator32)
+      return a32.ReleaseToOSIntervalMs();
+    return a64.ReleaseToOSIntervalMs();
+  }
+  void ForceReleaseToOS() {
+    if (UseAllocator32)
+      a32.ForceReleaseToOS();
+    else
+      a64.ForceReleaseToOS();
+  }
+  void PrintStats() {
+    if (UseAllocator32)
+      a32.PrintStats();
+    else
+      a64.PrintStats();
+  }
+};
+
+template <typename AddressSpaceView>
+using PrimaryAllocatorASVT = DoubleAllocator<Allocator32ASVT<AddressSpaceView>,
+                                             Allocator64ASVT<AddressSpaceView>>;
+#elif SANITIZER_CAN_USE_ALLOCATOR64
 # if SANITIZER_FUCHSIA
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
-typedef DefaultSizeClassMap SizeClassMap;
 # elif defined(__powerpc64__)
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x20000000000ULL;  // 2T.
-typedef DefaultSizeClassMap SizeClassMap;
-# elif defined(__aarch64__) && SANITIZER_ANDROID
-// Android needs to support 39, 42 and 48 bit VMA.
-const uptr kAllocatorSpace =  ~(uptr)0;
-const uptr kAllocatorSize  =  0x2000000000ULL;  // 128G.
-typedef VeryCompactSizeClassMap SizeClassMap;
-# elif defined(__aarch64__)
-// AArch64/SANITIZER_CAN_USE_ALLOCATOR64 is only for 42-bit VMA
-// so no need to different values for different VMA.
-const uptr kAllocatorSpace =  0x10000000000ULL;
-const uptr kAllocatorSize  =  0x10000000000ULL;  // 3T.
-typedef DefaultSizeClassMap SizeClassMap;
-#elif defined(__sparc__)
+# elif defined(__sparc__)
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize = 0x20000000000ULL;  // 2T.
-typedef DefaultSizeClassMap SizeClassMap;
 # elif SANITIZER_WINDOWS
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x8000000000ULL;  // 500G
-typedef DefaultSizeClassMap SizeClassMap;
 # else
 const uptr kAllocatorSpace = 0x600000000000ULL;
 const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
-typedef DefaultSizeClassMap SizeClassMap;
 # endif
+typedef DefaultSizeClassMap SizeClassMap;
+static inline uptr getKNumClasses() { return SizeClassMap::kNumClasses; }
+static inline uptr getKMaxSize() { return SizeClassMap::kMaxSize; }
+static inline uptr getClassID(uptr size) { return SizeClassMap::ClassID(size); }
+static const uptr kMaxNumberOfSizeClasses = SizeClassMap::kNumClasses;
 template <typename AddressSpaceViewTy>
 struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
   static const uptr kSpaceBeg = kAllocatorSpace;
@@ -164,9 +369,12 @@
 
 template <typename AddressSpaceView>
 using PrimaryAllocatorASVT = SizeClassAllocator64<AP64<AddressSpaceView>>;
-using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 #else  // Fallback to SizeClassAllocator32.
 typedef CompactSizeClassMap SizeClassMap;
+static inline uptr getKNumClasses() { return SizeClassMap::kNumClasses; }
+static inline uptr getKMaxSize() { return SizeClassMap::kMaxSize; }
+static inline uptr getClassID(uptr size) { return SizeClassMap::ClassID(size); }
+static const uptr kMaxNumberOfSizeClasses = SizeClassMap::kNumClasses;
 template <typename AddressSpaceViewTy>
 struct AP32 {
   static const uptr kSpaceBeg = 0;
@@ -180,16 +388,14 @@
 };
 template <typename AddressSpaceView>
 using PrimaryAllocatorASVT = SizeClassAllocator32<AP32<AddressSpaceView> >;
-using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 #endif  // SANITIZER_CAN_USE_ALLOCATOR64
 
-static const uptr kNumberOfSizeClasses = SizeClassMap::kNumClasses;
-
 template <typename AddressSpaceView>
 using AsanAllocatorASVT =
     CombinedAllocator<PrimaryAllocatorASVT<AddressSpaceView>>;
 using AsanAllocator = AsanAllocatorASVT<LocalAddressSpaceView>;
 using AllocatorCache = AsanAllocator::AllocatorCache;
+using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 
 struct AsanThreadLocalMallocStorage {
   uptr quarantine_cache[16];
Index: compiler-rt/lib/asan/asan_allocator.cc
===================================================================
--- compiler-rt/lib/asan/asan_allocator.cc
+++ compiler-rt/lib/asan/asan_allocator.cc
@@ -31,6 +31,7 @@
 #include "lsan/lsan_common.h"
 
 namespace __asan {
+bool UseAllocator32 = false;
 
 // Valid redzone sizes are 16, 32, 64, ... 2048, so we encode them in 3 bits.
 // We use adaptive redzones: for larger allocation larger redzones are used.
@@ -113,7 +114,7 @@
 struct AsanChunk: ChunkBase {
   uptr Beg() { return reinterpret_cast<uptr>(this) + kChunkHeaderSize; }
   uptr UsedSize(bool locked_version = false) {
-    if (user_requested_size != SizeClassMap::kMaxSize)
+    if (user_requested_size != getKMaxSize())
       return user_requested_size;
     return *reinterpret_cast<uptr *>(
                get_allocator().GetMetaData(AllocBeg(locked_version)));
@@ -277,6 +278,12 @@
   }
 
   void InitLinkerInitialized(const AllocatorOptions &options) {
+    // Check whether the address space is 47-bit, that is large enough for the
+    // 64-bit allocator.
+    if (GetMaxVirtualAddress() < (((uptr)1ULL << 48) - 1))
+      UseAllocator32 = true;
+    else
+      UseAllocator32 = false;
     SetAllocatorMayReturnNull(options.may_return_null);
     allocator.InitLinkerInitialized(options.release_to_os_interval_ms);
     SharedInitCode(options);
@@ -499,7 +506,7 @@
       CHECK(allocator.FromPrimary(allocated));
     } else {
       CHECK(!allocator.FromPrimary(allocated));
-      m->user_requested_size = SizeClassMap::kMaxSize;
+      m->user_requested_size = getKMaxSize();
       uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(allocated));
       meta[0] = size;
       meta[1] = chunk_beg;
@@ -524,10 +531,10 @@
     thread_stats.mallocs++;
     thread_stats.malloced += size;
     thread_stats.malloced_redzones += needed_size - size;
-    if (needed_size > SizeClassMap::kMaxSize)
+    if (needed_size > getKMaxSize())
       thread_stats.malloc_large++;
     else
-      thread_stats.malloced_by_size[SizeClassMap::ClassID(needed_size)]++;
+      thread_stats.malloced_by_size[getClassID(needed_size)]++;
 
     void *res = reinterpret_cast<void *>(user_beg);
     if (can_fill && fl.max_malloc_fill_size) {
Index: compiler-rt/lib/asan/asan_stats.h
===================================================================
--- compiler-rt/lib/asan/asan_stats.h
+++ compiler-rt/lib/asan/asan_stats.h
@@ -38,7 +38,7 @@
   uptr munmaps;
   uptr munmaped;
   uptr malloc_large;
-  uptr malloced_by_size[kNumberOfSizeClasses];
+  uptr malloced_by_size[kMaxNumberOfSizeClasses];
 
   // Ctor for global AsanStats (accumulated stats for dead threads).
   explicit AsanStats(LinkerInitialized) { }
Index: compiler-rt/lib/asan/asan_stats.cc
===================================================================
--- compiler-rt/lib/asan/asan_stats.cc
+++ compiler-rt/lib/asan/asan_stats.cc
@@ -30,9 +30,9 @@
 }
 
 static void PrintMallocStatsArray(const char *prefix,
-                                  uptr (&array)[kNumberOfSizeClasses]) {
+                                  uptr *array) {
   Printf("%s", prefix);
-  for (uptr i = 0; i < kNumberOfSizeClasses; i++) {
+  for (uptr i = 0; i < getKNumClasses(); i++) {
     if (!array[i]) continue;
     Printf("%zu:%zu; ", i, array[i]);
   }
Index: compiler-rt/lib/lsan/lsan_allocator.h
===================================================================
--- compiler-rt/lib/lsan/lsan_allocator.h
+++ compiler-rt/lib/lsan/lsan_allocator.h
@@ -49,8 +49,171 @@
   u32 stack_trace_id;
 };
 
-#if defined(__mips64) || defined(__aarch64__) || defined(__i386__) || \
-    defined(__arm__)
+#if defined(__aarch64__)
+
+template <typename AddressSpaceViewTy>
+struct AP32 {
+  static const uptr kSpaceBeg = 0;
+  static const u64 kSpaceSize = SANITIZER_MMAP_RANGE_SIZE;
+  static const uptr kMetadataSize = sizeof(ChunkMetadata);
+  typedef __sanitizer::CompactSizeClassMap SizeClassMap;
+  static const uptr kRegionSizeLog = 20;
+  using AddressSpaceView = AddressSpaceViewTy;
+  typedef NoOpMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+};
+
+const uptr kAllocatorSpace = 0x600000000000ULL;
+const uptr kAllocatorSize  = 0x40000000000ULL;  // 4T.
+
+template <typename AddressSpaceViewTy>
+struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
+  static const uptr kSpaceBeg = kAllocatorSpace;
+  static const uptr kSpaceSize = kAllocatorSize;
+  static const uptr kMetadataSize = sizeof(ChunkMetadata);
+  typedef DefaultSizeClassMap SizeClassMap;
+  typedef NoOpMapUnmapCallback MapUnmapCallback;
+  static const uptr kFlags = 0;
+  using AddressSpaceView = AddressSpaceViewTy;
+};
+
+template <typename AddressSpaceView>
+using Allocator32ASVT = SizeClassAllocator32<AP32<AddressSpaceView>>;
+template <typename AddressSpaceView>
+using Allocator64ASVT = SizeClassAllocator64<AP64<AddressSpaceView>>;
+
+using Allocator32 = Allocator32ASVT<LocalAddressSpaceView>;
+using Allocator64 = Allocator64ASVT<LocalAddressSpaceView>;
+
+extern bool UseAllocator32;
+
+template <class A32, class A64>
+class DoubleAllocator {
+  A32 a32;
+  A64 a64;
+
+ public:
+  class DoubleAllocatorCache {
+    typename A32::AllocatorCache a32;
+    typename A64::AllocatorCache a64;
+
+   public:
+    void Init(AllocatorGlobalStats *s) {
+      if (UseAllocator32)
+        a32.Init(s);
+      else
+        a64.Init(s);
+    }
+    void *Allocate(DoubleAllocator *allocator, uptr class_id) {
+      if (UseAllocator32)
+        return a32.Allocate(&allocator->a32, class_id);
+      return a64.Allocate(&allocator->a64, class_id);
+    }
+
+    void Deallocate(DoubleAllocator *allocator, uptr class_id, void *p) {
+      if (UseAllocator32)
+        a32.Deallocate(&allocator->a32, class_id, p);
+      else
+        a64.Deallocate(&allocator->a64, class_id, p);
+    }
+
+    void Drain(DoubleAllocator *allocator) {
+      if (UseAllocator32)
+        a32.Drain(&allocator->a32);
+      else
+        a64.Drain(&allocator->a64);
+    }
+
+    void Destroy(DoubleAllocator *allocator, AllocatorGlobalStats *s) {
+      if (UseAllocator32)
+        a32.Destroy(&allocator->a32, s);
+      else
+        a64.Destroy(&allocator->a64, s);
+    }
+  };
+
+  using MapUnmapCallback = Allocator32::MapUnmapCallback;
+  using AddressSpaceView = Allocator32::AddressSpaceView;
+  using AllocatorCache = DoubleAllocatorCache;
+
+  void Init(s32 release_to_os_interval_ms) {
+    if (UseAllocator32)
+      a32.Init(release_to_os_interval_ms);
+    else
+      a64.Init(release_to_os_interval_ms);
+  }
+
+  static bool CanAllocate(uptr size, uptr alignment) {
+    if (UseAllocator32)
+      return A32::CanAllocate(size, alignment);
+    return A64::CanAllocate(size, alignment);
+  }
+
+  static uptr ClassID(uptr size) {
+    if (UseAllocator32)
+      return A32::ClassID(size);
+    return A64::ClassID(size);
+  }
+
+  bool PointerIsMine(const void *p) {
+    if (UseAllocator32)
+      return a32.PointerIsMine(p);
+    return a64.PointerIsMine(p);
+  }
+
+  void *GetMetaData(const void *p) {
+    if (UseAllocator32)
+      return a32.GetMetaData(p);
+    return a64.GetMetaData(p);
+  }
+
+  uptr GetSizeClass(const void *p) {
+    if (UseAllocator32)
+      return a32.GetSizeClass(p);
+    return a64.GetSizeClass(p);
+  }
+
+  void ForEachChunk(ForEachChunkCallback callback, void *arg) {
+    if (UseAllocator32)
+      a32.ForEachChunk(callback, arg);
+    else
+      a64.ForEachChunk(callback, arg);
+  }
+
+  void TestOnlyUnmap() {
+    if (UseAllocator32)
+      a32.TestOnlyUnmap();
+    else
+      a64.TestOnlyUnmap();
+  }
+  void ForceLock() {
+    if (UseAllocator32)
+      a32.ForceLock();
+    else
+      a64.ForceLock();
+  }
+  void ForceUnlock() {
+    if (UseAllocator32)
+      a32.ForceUnlock();
+    else
+      a64.ForceUnlock();
+  }
+  void *GetBlockBegin(const void *p) {
+    if (UseAllocator32)
+      return a32.GetBlockBegin(p);
+    return a64.GetBlockBegin(p);
+  }
+  uptr GetActuallyAllocatedSize(void *p) {
+    if (UseAllocator32)
+      return a32.GetActuallyAllocatedSize(p);
+    return a64.GetActuallyAllocatedSize(p);
+  }
+};
+
+template <typename AddressSpaceView>
+using PrimaryAllocatorASVT = DoubleAllocator<Allocator32ASVT<AddressSpaceView>,
+                                             Allocator64ASVT<AddressSpaceView>>;
+#elif defined(__mips64) || defined(__i386__) || defined(__arm__)
 template <typename AddressSpaceViewTy>
 struct AP32 {
   static const uptr kSpaceBeg = 0;
@@ -64,7 +227,6 @@
 };
 template <typename AddressSpaceView>
 using PrimaryAllocatorASVT = SizeClassAllocator32<AP32<AddressSpaceView>>;
-using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 #elif defined(__x86_64__) || defined(__powerpc64__)
 # if defined(__powerpc64__)
 const uptr kAllocatorSpace = 0xa0000000000ULL;
@@ -86,13 +248,13 @@
 
 template <typename AddressSpaceView>
 using PrimaryAllocatorASVT = SizeClassAllocator64<AP64<AddressSpaceView>>;
-using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 #endif
 
 template <typename AddressSpaceView>
 using AllocatorASVT = CombinedAllocator<PrimaryAllocatorASVT<AddressSpaceView>>;
 using Allocator = AllocatorASVT<LocalAddressSpaceView>;
 using AllocatorCache = Allocator::AllocatorCache;
+using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 
 Allocator::AllocatorCache *GetAllocatorCache();
 
Index: compiler-rt/lib/lsan/lsan_allocator.cc
===================================================================
--- compiler-rt/lib/lsan/lsan_allocator.cc
+++ compiler-rt/lib/lsan/lsan_allocator.cc
@@ -35,8 +35,16 @@
 #endif
 
 static Allocator allocator;
+bool UseAllocator32 = false;
 
 void InitializeAllocator() {
+  // Check whether the address space is 47-bit, that is large enough for the
+  // 64-bit allocator.
+  if (GetMaxVirtualAddress() < (((uptr)1 << 48) - 1))
+    UseAllocator32 = true;
+  else
+    UseAllocator32 = false;
+
   SetAllocatorMayReturnNull(common_flags()->allocator_may_return_null);
   allocator.InitLinkerInitialized(
       common_flags()->allocator_release_to_os_interval_ms);
Index: compiler-rt/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
===================================================================
--- compiler-rt/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
+++ compiler-rt/lib/sanitizer_common/tests/sanitizer_allocator_test.cc
@@ -690,6 +690,123 @@
   TestCombinedAllocator<Allocator64Dynamic>();
 }
 
+static bool use1 = false;
+
+template <class A1, class A2>
+class DoubleAllocator {
+  A1 a1;
+  A2 a2;
+
+ public:
+  class DoubleAllocatorCache {
+    typename A1::AllocatorCache a1;
+    typename A2::AllocatorCache a2;
+
+   public:
+    void Init(AllocatorGlobalStats *s) {
+      if (use1)
+        return a1.Init(s);
+      else
+        return a2.Init(s);
+    }
+    void *Allocate(DoubleAllocator *allocator, uptr class_id) {
+      if (use1)
+        return a1.Allocate(&allocator->a1, class_id);
+      else
+        return a2.Allocate(&allocator->a2, class_id);
+    }
+
+    void Deallocate(DoubleAllocator *allocator, uptr class_id, void *p) {
+      if (use1)
+        return a1.Deallocate(&allocator->a1, class_id, p);
+      else
+        return a2.Deallocate(&allocator->a2, class_id, p);
+    }
+
+    void Drain(DoubleAllocator *allocator) {
+      if (use1)
+        return a1.Drain(&allocator->a1);
+      else
+        return a2.Drain(&allocator->a2);
+    }
+
+    void Destroy(DoubleAllocator *allocator, AllocatorGlobalStats *s) {
+      if (use1)
+        return a1.Destroy(&allocator->a1, s);
+      else
+        return a2.Destroy(&allocator->a2, s);
+    }
+  };
+
+  using MapUnmapCallback = Allocator32Compact::MapUnmapCallback;
+  using AddressSpaceView = Allocator32Compact::AddressSpaceView;
+  using AllocatorCache = DoubleAllocatorCache;
+
+  void Init(s32 release_to_os_interval_ms) {
+    if (use1)
+      return a1.Init(release_to_os_interval_ms);
+    else
+      return a2.Init(release_to_os_interval_ms);
+  }
+
+  static bool CanAllocate(uptr size, uptr alignment) {
+    if (use1)
+      return A1::CanAllocate(size, alignment);
+    else
+      return A2::CanAllocate(size, alignment);
+  }
+
+  static uptr ClassID(uptr size) {
+    if (use1)
+      return A1::ClassID(size);
+    else
+      return A2::ClassID(size);
+  }
+
+  bool PointerIsMine(const void *p) {
+    if (use1)
+      return a1.PointerIsMine(p);
+    else
+      return a2.PointerIsMine(p);
+  }
+
+  void *GetMetaData(const void *p) {
+    if (use1)
+      return a1.GetMetaData(p);
+    else
+      return a2.GetMetaData(p);
+  }
+
+  uptr GetSizeClass(const void *p) {
+    if (use1)
+      return a1.GetSizeClass(p);
+    else
+      return a2.GetSizeClass(p);
+  }
+
+  void ForEachChunk(ForEachChunkCallback callback, void *arg) {
+    if (use1)
+      return a1.ForEachChunk(callback, arg);
+    else
+      return a2.ForEachChunk(callback, arg);
+  }
+
+  void TestOnlyUnmap() {
+    if (use1)
+      return a1.TestOnlyUnmap();
+    else
+      return a2.TestOnlyUnmap();
+  }
+};
+
+TEST(SanitizerCommon, CombinedDoubleAllocator) {
+  TestCombinedAllocator<
+      DoubleAllocator<Allocator32Compact, Allocator64Compact>>();
+  use1 = true;
+  TestCombinedAllocator<
+      DoubleAllocator<Allocator32Compact, Allocator64Compact>>();
+}
+
 #if !SANITIZER_ANDROID
 TEST(SanitizerCommon, CombinedAllocator64Compact) {
   TestCombinedAllocator<Allocator64Compact>();