Codegen support for the llvm.invariant/lifetime.start/end intrinsics:

just throw them away.

llvm-svn: 86678

2 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/IntrinsicLowering.cpp b/llvm/lib/CodeGen/IntrinsicLowering.cpp
index 3e3b28a8109..8a3bd0bf4e0 100644
--- a/llvm/lib/CodeGen/IntrinsicLowering.cpp
+++ b/llvm/lib/CodeGen/IntrinsicLowering.cpp
@@ -515,6 +515,15 @@ void IntrinsicLowering::LowerIntrinsicCall(CallInst *CI) {
      if (CI->getType() != Type::getVoidTy(Context))
        CI->replaceAllUsesWith(ConstantInt::get(CI->getType(), 1));
      break;
+  case Intrinsic::invariant_start:
+  case Intrinsic::lifetime_start:
+    // Discard region information.
+    CI->replaceAllUsesWith(UndefValue::get(CI->getType()));
+    break;
+  case Intrinsic::invariant_end:
+  case Intrinsic::lifetime_end:
+    // Discard region information.
+    break;
   }
 
   assert(CI->use_empty() &&
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index ee8bf791715..9818e62a404 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -4409,6 +4409,16 @@ SelectionDAGLowering::visitIntrinsicCall(CallInst &I, unsigned Intrinsic) {
     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;
   }
 }