1 files changed, 62 insertions, 0 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 929a72ac687e..7833bfc1d1b6 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -167,6 +167,10 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
   // Sub-word ATOMIC_CMP_SWAP need to ensure that the input is zero-extended.
   setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i32, Custom);
 
+  // Custom lower inline assembly to check for special registers.
+  setOperationAction(ISD::INLINEASM, MVT::Other, Custom);
+  setOperationAction(ISD::INLINEASM_BR, MVT::Other, Custom);
+
   // PowerPC has an i16 but no i8 (or i1) SEXTLOAD.
   for (MVT VT : MVT::integer_valuetypes()) {
     setLoadExtAction(ISD::SEXTLOAD, VT, MVT::i1, Promote);
@@ -3461,6 +3465,57 @@ SDValue PPCTargetLowering::LowerADJUST_TRAMPOLINE(SDValue Op,
   return Op.getOperand(0);
 }
 
+SDValue PPCTargetLowering::LowerINLINEASM(SDValue Op, SelectionDAG &DAG) const {
+  MachineFunction &MF = DAG.getMachineFunction();
+  PPCFunctionInfo &MFI = *MF.getInfo<PPCFunctionInfo>();
+
+  assert((Op.getOpcode() == ISD::INLINEASM ||
+          Op.getOpcode() == ISD::INLINEASM_BR) &&
+         "Expecting Inline ASM node.");
+
+  // If an LR store is already known to be required then there is not point in
+  // checking this ASM as well.
+  if (MFI.isLRStoreRequired())
+    return Op;
+
+  // Inline ASM nodes have an optional last operand that is an incoming Flag of
+  // type MVT::Glue. We want to ignore this last operand if that is the case.
+  unsigned NumOps = Op.getNumOperands();
+  if (Op.getOperand(NumOps - 1).getValueType() == MVT::Glue)
+    --NumOps;
+
+  // Check all operands that may contain the LR.
+  for (unsigned i = InlineAsm::Op_FirstOperand; i != NumOps;) {
+    unsigned Flags = cast<ConstantSDNode>(Op.getOperand(i))->getZExtValue();
+    unsigned NumVals = InlineAsm::getNumOperandRegisters(Flags);
+    ++i; // Skip the ID value.
+
+    switch (InlineAsm::getKind(Flags)) {
+    default:
+      llvm_unreachable("Bad flags!");
+    case InlineAsm::Kind_RegUse:
+    case InlineAsm::Kind_Imm:
+    case InlineAsm::Kind_Mem:
+      i += NumVals;
+      break;
+    case InlineAsm::Kind_Clobber:
+    case InlineAsm::Kind_RegDef:
+    case InlineAsm::Kind_RegDefEarlyClobber: {
+      for (; NumVals; --NumVals, ++i) {
+        Register Reg = cast<RegisterSDNode>(Op.getOperand(i))->getReg();
+        if (Reg != PPC::LR && Reg != PPC::LR8)
+          continue;
+        MFI.setLRStoreRequired();
+        return Op;
+      }
+      break;
+    }
+    }
+  }
+
+  return Op;
+}
+
 SDValue PPCTargetLowering::LowerINIT_TRAMPOLINE(SDValue Op,
                                                 SelectionDAG &DAG) const {
   if (Subtarget.isAIXABI())
@@ -10316,6 +10371,8 @@ SDValue PPCTargetLowering::LowerOperation(SDValue Op, SelectionDAG &DAG) const {
   case ISD::INIT_TRAMPOLINE:    return LowerINIT_TRAMPOLINE(Op, DAG);
   case ISD::ADJUST_TRAMPOLINE:  return LowerADJUST_TRAMPOLINE(Op, DAG);
 
+  case ISD::INLINEASM:
+  case ISD::INLINEASM_BR:       return LowerINLINEASM(Op, DAG);
   // Variable argument lowering.
   case ISD::VASTART:            return LowerVASTART(Op, DAG);
   case ISD::VAARG:              return LowerVAARG(Op, DAG);
@@ -15090,6 +15147,11 @@ PPCTargetLowering::getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
       return std::make_pair(0U, &PPC::VSSRCRegClass);
     else
       return std::make_pair(0U, &PPC::VSFRCRegClass);
+  } else if (Constraint == "lr") {
+    if (VT == MVT::i64)
+      return std::make_pair(0U, &PPC::LR8RCRegClass);
+    else
+      return std::make_pair(0U, &PPC::LRRCRegClass);
   }
 
   // If we name a VSX register, we can't defer to the base class because it