diff --git a/compiler-rt/lib/hwasan/hwasan_allocator.cpp b/compiler-rt/lib/hwasan/hwasan_allocator.cpp
--- a/compiler-rt/lib/hwasan/hwasan_allocator.cpp
+++ b/compiler-rt/lib/hwasan/hwasan_allocator.cpp
@@ -163,7 +163,7 @@
 static void *HwasanAllocate(StackTrace *stack, uptr orig_size, uptr alignment,
                             bool zeroise) {
   // Keep this consistent with LSAN and ASAN behavior.
-  if (orig_size == 0)
+  if (UNLIKELY(orig_size == 0))
     orig_size = 1;
   if (orig_size > kMaxAllowedMallocSize) {
     if (AllocatorMayReturnNull()) {