Subzero: Improve malloc/free behavior.

src/IceCfg.h

 //===- subzero/src/IceCfg.h - Control flow graph ----------------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the Cfg class, which represents the control flow
@@ skipping 146 matching lines @@
   template <typename T> void deallocateArrayOf(T *Array) {
     Allocator.Deallocate(Array);
   }
 
 private:
   // TODO: for now, everything is allocated from the same allocator. In the
   // future we may want to split this to several allocators, for example in
   // order to use a "Recycler" to preserve memory. If we keep all allocation
   // requests from the Cfg exposed via methods, we can always switch the
   // implementation over at a later point.
-  llvm::BumpPtrAllocator Allocator;
+  llvm::BumpPtrAllocatorImpl<llvm::MallocAllocator, 1024 * 1024> Allocator;
 
   GlobalContext *Ctx;
   IceString FunctionName;
   Type ReturnType;
   bool IsInternalLinkage;
   bool HasError;
   bool FocusedTiming;
   IceString ErrorMessage;
   CfgNode *Entry; // entry basic block
   NodeList Nodes; // linearized node list; Entry should be first
@@ skipping 10 matching lines @@
   // validating Variable::DefNode.  Normally, a traversal over
   // CfgNodes maintains this, but before global operations like
   // register allocation, resetCurrentNode() should be called to avoid
   // spurious validation failures.
   const CfgNode *CurrentNode;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICECFG_H