Have LowerOperandForConstraint handle multiple character constraints.

Part of rdar://9119939


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132510 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCISelLowering.cpp b/lib/Target/PowerPC/PPCISelLowering.cpp
index a5a3b01..5031a79 100644
--- a/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -5439,10 +5439,16 @@
 
 /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
 /// vector.  If it is invalid, don't add anything to Ops.
-void PPCTargetLowering::LowerAsmOperandForConstraint(SDValue Op, char Letter,
+void PPCTargetLowering::LowerAsmOperandForConstraint(SDValue Op, 
+                                                     std::string &Constraint,
                                                      std::vector<SDValue>&Ops,
                                                      SelectionDAG &DAG) const {
   SDValue Result(0,0);
+  
+  // Only support length 1 constraints.
+  if (Constraint.length() > 1) return;
+  
+  char Letter = Constraint[0];
   switch (Letter) {
   default: break;
   case 'I':
@@ -5498,7 +5504,7 @@
   }
 
   // Handle standard constraint letters.
-  TargetLowering::LowerAsmOperandForConstraint(Op, Letter, Ops, DAG);
+  TargetLowering::LowerAsmOperandForConstraint(Op, Constraint, Ops, DAG);
 }
 
 // isLegalAddressingMode - Return true if the addressing mode represented
diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 64a57a1..986b4e7 100644
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -328,7 +328,7 @@
     /// LowerAsmOperandForConstraint - Lower the specified operand into the Ops
     /// vector.  If it is invalid, don't add anything to Ops.
     virtual void LowerAsmOperandForConstraint(SDValue Op,
-                                              char ConstraintLetter,
+                                              std::string &Constraint,
                                               std::vector<SDValue> &Ops,
                                               SelectionDAG &DAG) const;