Codegen support for the llvm.invariant/lifetime.start/end intrinsics:
just throw them away.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86678 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index ee8bf79..9818e62 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -4409,6 +4409,16 @@
     return implVisitBinaryAtomic(I, ISD::ATOMIC_LOAD_UMAX);
   case Intrinsic::atomic_swap:
     return implVisitBinaryAtomic(I, ISD::ATOMIC_SWAP);
+
+  case Intrinsic::invariant_start:
+  case Intrinsic::lifetime_start:
+    // Discard region information.
+    setValue(&I, DAG.getUNDEF(TLI.getPointerTy()));
+    return 0;
+  case Intrinsic::invariant_end:
+  case Intrinsic::lifetime_end:
+    // Discard region information.
+    return 0;
   }
 }