diff --git a/compiler-rt/lib/asan/asan_allocator.cpp b/compiler-rt/lib/asan/asan_allocator.cpp
--- a/compiler-rt/lib/asan/asan_allocator.cpp
+++ b/compiler-rt/lib/asan/asan_allocator.cpp
@@ -161,15 +161,16 @@
 };
 
 class LargeChunkHeader {
-  atomic_uint64_t magic;
+  atomic_uintptr_t magic;
   AsanChunk *chunk_header;
-  static constexpr uptr kAllocBegMagic = 0xCC6E96B9;
+  static constexpr uptr kAllocBegMagic =
+      FIRST_32_SECOND_64(0xCC6E96B9, 0xCC6E96B9CC6E96B9ULL);
 
  public:
-  AsanChunk *Get() {
+  AsanChunk *Get() const {
     return atomic_load(&magic, memory_order_acquire) == kAllocBegMagic
                ? chunk_header
-               : reinterpret_cast<AsanChunk *>(this);
+               : nullptr;
   }
 
   void Set(AsanChunk *p) {
@@ -179,7 +180,7 @@
       return;
     }
 
-    u64 old = kAllocBegMagic;
+    uptr old = kAllocBegMagic;
     if (!atomic_compare_exchange_strong(&magic, &old, 0,
                                         memory_order_release)) {
       CHECK_EQ(old, kAllocBegMagic);
@@ -509,13 +510,10 @@
     uptr needed_size = rounded_size + rz_size;
     if (alignment > min_alignment)
       needed_size += alignment;
-    bool using_primary_allocator = true;
     // If we are allocating from the secondary allocator, there will be no
     // automatic right redzone, so add the right redzone manually.
-    if (!PrimaryAllocator::CanAllocate(needed_size, alignment)) {
+    if (!PrimaryAllocator::CanAllocate(needed_size, alignment))
       needed_size += rz_size;
-      using_primary_allocator = false;
-    }
     CHECK(IsAligned(needed_size, min_alignment));
     if (size > kMaxAllowedMallocSize || needed_size > kMaxAllowedMallocSize ||
         size > max_user_defined_malloc_size) {
@@ -567,13 +565,6 @@
     m->alloc_type = alloc_type;
     CHECK(size);
     m->SetUsedSize(size);
-    if (using_primary_allocator) {
-      CHECK(allocator.FromPrimary(allocated));
-    } else {
-      CHECK(!allocator.FromPrimary(allocated));
-      uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(allocated));
-      meta[1] = chunk_beg;
-    }
     m->user_requested_alignment_log = user_requested_alignment_log;
 
     m->SetAllocContext(t ? t->tid() : 0, StackDepotPut(*stack));
@@ -781,15 +772,12 @@
   AsanChunk *GetAsanChunk(void *alloc_beg) {
     if (!alloc_beg)
       return nullptr;
-    AsanChunk *p = nullptr;
-    if (!allocator.FromPrimary(alloc_beg)) {
-      uptr *meta = reinterpret_cast<uptr *>(allocator.GetMetaData(alloc_beg));
-      p = reinterpret_cast<AsanChunk *>(meta[1]);
-    } else {
-      p = reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Get();
+    AsanChunk *p = reinterpret_cast<LargeChunkHeader *>(alloc_beg)->Get();
+    if (!p) {
+      if (!allocator.FromPrimary(alloc_beg))
+        return nullptr;
+      p = reinterpret_cast<AsanChunk *>(alloc_beg);
     }
-    if (!p)
-      return nullptr;
     u8 state = atomic_load(&p->chunk_state, memory_order_relaxed);
     // It does not guaranty that Chunk is initialized, but it's
     // definitely not for any other value.