If there's an unaligned memcpy to/from the stack, don't lower it. Just call the

memcpy library function instead.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43270 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 0 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 610c898d17..71999b44c1 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -4329,6 +4329,19 @@ void SelectionDAGLowering::visitMemIntrinsic(CallInst &I, unsigned Op) {
           }
         }
 
+        // Check to see if there is an unaligned memcpy from/onto the stack. If
+        // so, then ignore it for the present.
+        if (Op1.getOpcode() == ISD::FrameIndex ||
+            Op2.getOpcode() == ISD::FrameIndex) {
+          unsigned TotalSize = 0;
+
+          for (unsigned i = 0; i < NumMemOps; i++)
+            TotalSize += MVT::getSizeInBits(MemOps[i]) / 8;
+
+          if (TotalSize % Align != 0)
+            break;
+        }
+
         for (unsigned i = 0; i < NumMemOps; i++) {
           MVT::ValueType VT = MemOps[i];
           unsigned VTSize = MVT::getSizeInBits(VT) / 8;