Add dummy inline asm handling for 'r' constraint. This fixes PR4778

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80085 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/MSP430/AsmPrinter/MSP430AsmPrinter.cpp b/lib/Target/MSP430/AsmPrinter/MSP430AsmPrinter.cpp
index 8724eef..6e2e959 100644
--- a/lib/Target/MSP430/AsmPrinter/MSP430AsmPrinter.cpp
+++ b/lib/Target/MSP430/AsmPrinter/MSP430AsmPrinter.cpp
@@ -58,6 +58,9 @@
     void printCCOperand(const MachineInstr *MI, int OpNum);
     void printInstruction(const MachineInstr *MI);  // autogenerated.
     void printMachineInstruction(const MachineInstr * MI);
+    bool PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
+                         unsigned AsmVariant,
+                         const char *ExtraCode);
 
     void emitFunctionHeader(const MachineFunction &MF);
     bool runOnMachineFunction(MachineFunction &F);
@@ -243,6 +246,19 @@
   }
 }
 
+/// PrintAsmOperand - Print out an operand for an inline asm expression.
+///
+bool MSP430AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
+                                       unsigned AsmVariant,
+                                       const char *ExtraCode) {
+  // Does this asm operand have a single letter operand modifier?
+  if (ExtraCode && ExtraCode[0])
+    return true; // Unknown modifier.
+
+  printOperand(MI, OpNo);
+  return false;
+}
+
 // Force static initialization.
 extern "C" void LLVMInitializeMSP430AsmPrinter() {
   RegisterAsmPrinter<MSP430AsmPrinter> X(TheMSP430Target);
diff --git a/lib/Target/MSP430/MSP430ISelLowering.cpp b/lib/Target/MSP430/MSP430ISelLowering.cpp
index 3e6169e..4c3e398 100644
--- a/lib/Target/MSP430/MSP430ISelLowering.cpp
+++ b/lib/Target/MSP430/MSP430ISelLowering.cpp
@@ -151,6 +151,44 @@
 }
 
 //===----------------------------------------------------------------------===//
+//                       MSP430 Inline Assembly Support
+//===----------------------------------------------------------------------===//
+
+/// getConstraintType - Given a constraint letter, return the type of
+/// constraint it is for this target.
+TargetLowering::ConstraintType
+MSP430TargetLowering::getConstraintType(const std::string &Constraint) const {
+  if (Constraint.size() == 1) {
+    switch (Constraint[0]) {
+    case 'r':
+      return C_RegisterClass;
+    default:
+      break;
+    }
+  }
+  return TargetLowering::getConstraintType(Constraint);
+}
+
+std::pair<unsigned, const TargetRegisterClass*>
+MSP430TargetLowering::
+getRegForInlineAsmConstraint(const std::string &Constraint,
+                             EVT VT) const {
+  if (Constraint.size() == 1) {
+    // GCC Constraint Letters
+    switch (Constraint[0]) {
+    default: break;
+    case 'r':   // GENERAL_REGS
+      if (VT == MVT::i8)
+        return std::make_pair(0U, MSP430::GR8RegisterClass);
+
+      return std::make_pair(0U, MSP430::GR16RegisterClass);
+    }
+  }
+
+  return TargetLowering::getRegForInlineAsmConstraint(Constraint, VT);
+}
+
+//===----------------------------------------------------------------------===//
 //                      Calling Convention Implementation
 //===----------------------------------------------------------------------===//
 
diff --git a/lib/Target/MSP430/MSP430ISelLowering.h b/lib/Target/MSP430/MSP430ISelLowering.h
index 1339ccd..7947b0f 100644
--- a/lib/Target/MSP430/MSP430ISelLowering.h
+++ b/lib/Target/MSP430/MSP430ISelLowering.h
@@ -84,6 +84,11 @@
     SDValue LowerSELECT_CC(SDValue Op, SelectionDAG &DAG);
     SDValue LowerSIGN_EXTEND(SDValue Op, SelectionDAG &DAG);
 
+    TargetLowering::ConstraintType
+    getConstraintType(const std::string &Constraint) const;
+    std::pair<unsigned, const TargetRegisterClass*>
+    getRegForInlineAsmConstraint(const std::string &Constraint, EVT VT) const;
+
     MachineBasicBlock* EmitInstrWithCustomInserter(MachineInstr *MI,
                                                    MachineBasicBlock *BB) const;