1 files changed, 3 insertions, 0 deletions
diff --git a/include/llvm/Target/TargetMachine.h b/include/llvm/Target/TargetMachine.h
index 7f04119ae6..fd7228a513 100644
--- a/include/llvm/Target/TargetMachine.h
+++ b/include/llvm/Target/TargetMachine.h
@@ -102,11 +102,14 @@ public:
   void resetTargetOptions(const MachineFunction *MF) const;
 
   // Interfaces to the major aspects of target machine information:
+  // 
   // -- Instruction opcode and operand information
   // -- Pipelines and scheduling information
   // -- Stack frame information
   // -- Selection DAG lowering information
   //
+  // N.B. These objects may change during compilation. It's not safe to cache
+  // them between functions.
   virtual const TargetInstrInfo         *getInstrInfo() const { return 0; }
   virtual const TargetFrameLowering *getFrameLowering() const { return 0; }
   virtual const TargetLowering    *getTargetLowering() const { return 0; }