1 files changed, 32 insertions, 2 deletions
diff --git a/lib/Target/ARM/ThumbInstrInfo.cpp b/lib/Target/ARM/ThumbInstrInfo.cpp
index 075d940bcc..d9a499dacd 100644
--- a/lib/Target/ARM/ThumbInstrInfo.cpp
+++ b/lib/Target/ARM/ThumbInstrInfo.cpp
@@ -23,7 +23,7 @@
 using namespace llvm;
 
 ThumbInstrInfo::ThumbInstrInfo(const ARMSubtarget &STI)
-  : ARMBaseInstrInfo(STI) {
+  : ARMBaseInstrInfo(STI), RI(*this, STI) {
 }
 
 bool ThumbInstrInfo::isMoveInstr(const MachineInstr &MI,
@@ -114,6 +114,37 @@ bool ThumbInstrInfo::copyRegToReg(MachineBasicBlock &MBB,
   return false;
 }
 
+bool ThumbInstrInfo::
+canFoldMemoryOperand(const MachineInstr *MI,
+                     const SmallVectorImpl<unsigned> &Ops) const {
+  if (Ops.size() != 1) return false;
+
+  unsigned OpNum = Ops[0];
+  unsigned Opc = MI->getOpcode();
+  switch (Opc) {
+  default: break;
+  case ARM::tMOVr:
+  case ARM::tMOVlor2hir:
+  case ARM::tMOVhir2lor:
+  case ARM::tMOVhir2hir: {
+    if (OpNum == 0) { // move -> store
+      unsigned SrcReg = MI->getOperand(1).getReg();
+      if (RI.isPhysicalRegister(SrcReg) && !RI.isLowRegister(SrcReg))
+        // tSpill cannot take a high register operand.
+        return false;
+    } else {          // move -> load
+      unsigned DstReg = MI->getOperand(0).getReg();
+      if (RI.isPhysicalRegister(DstReg) && !RI.isLowRegister(DstReg))
+        // tRestore cannot target a high register operand.
+        return false;
+    }
+    return true;
+  }
+  }
+
+  return false;
+}
+
 void ThumbInstrInfo::
 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
                     unsigned SrcReg, bool isKill, int FI,
@@ -244,7 +275,6 @@ MachineInstr *ThumbInstrInfo::
 foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI,
                       const SmallVectorImpl<unsigned> &Ops, int FI) const {
   if (Ops.size() != 1) return NULL;
-  const ARMRegisterInfo &RI = getRegisterInfo();
 
   unsigned OpNum = Ops[0];
   unsigned Opc = MI->getOpcode();