Index: include/llvm/Support/Allocator.h
===================================================================
--- include/llvm/Support/Allocator.h
+++ include/llvm/Support/Allocator.h
@@ -201,9 +201,6 @@
 
   /// \brief Allocate space at the specified alignment.
   void *Allocate(size_t Size, size_t Alignment) {
-    if (!CurPtr) // Start a new slab if we haven't allocated one already.
-      StartNewSlab();
-
     // Keep track of how many bytes we've allocated.
     BytesAllocated += Size;
 
Index: unittests/Support/AllocatorTest.cpp
===================================================================
--- unittests/Support/AllocatorTest.cpp
+++ unittests/Support/AllocatorTest.cpp
@@ -112,7 +112,7 @@
   BumpPtrAllocator Alloc;
 
   Alloc.Allocate(8000, 0);
-  EXPECT_EQ(2U, Alloc.GetNumSlabs());
+  EXPECT_EQ(1U, Alloc.GetNumSlabs());
 }
 
 // Mock slab allocator that returns slabs aligned on 4096 bytes.  There is no