initial support for frame pointers


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31197 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelDAGToDAG.cpp b/lib/Target/ARM/ARMISelDAGToDAG.cpp
index b57bf59..7221818 100644
--- a/lib/Target/ARM/ARMISelDAGToDAG.cpp
+++ b/lib/Target/ARM/ARMISelDAGToDAG.cpp
@@ -91,10 +91,13 @@
   setOperationAction(ISD::VASTART,       MVT::Other, Custom);
   setOperationAction(ISD::VACOPY,            MVT::Other, Expand);
   setOperationAction(ISD::VAEND,         MVT::Other, Expand);
+  setOperationAction(ISD::DYNAMIC_STACKALLOC, MVT::i32, Expand);
 
   setOperationAction(ISD::ConstantFP, MVT::f64, Expand);
   setOperationAction(ISD::ConstantFP, MVT::f32, Expand);
 
+  setStackPointerRegisterToSaveRestore(ARM::R13);
+
   setSchedulingPreference(SchedulingForRegPressure);
   computeRegisterProperties();
 }