[TII] Use optional destination and source pair as a return value; NFC

Refactor usage of isCopyInstrImpl, isCopyInstr and isAddImmediate methods
to return optional machine operand pair of destination and source
registers.

Patch by Nikola Prica

Differential Revision: https://reviews.llvm.org/D69622

2 files changed, 13 insertions, 10 deletions

diff --git a/llvm/lib/CodeGen/LiveDebugValues.cpp b/llvm/lib/CodeGen/LiveDebugValues.cpp
index b15c594a454..d38840b7d8a 100644
--- a/llvm/lib/CodeGen/LiveDebugValues.cpp
+++ b/llvm/lib/CodeGen/LiveDebugValues.cpp
@@ -997,10 +997,14 @@ void LiveDebugValues::transferRegisterCopy(MachineInstr &MI,
                                            OpenRangesSet &OpenRanges,
                                            VarLocMap &VarLocIDs,
                                            TransferMap &Transfers) {
-  const MachineOperand *SrcRegOp, *DestRegOp;
 
-  if (!TII->isCopyInstr(MI, SrcRegOp, DestRegOp) || !SrcRegOp->isKill() ||
-      !DestRegOp->isDef())
+  auto DestSrc = TII->isCopyInstr(MI);
+  if (!DestSrc)
+    return;
+
+  const MachineOperand &DestRegOp = DestSrc->Destination;
+  const MachineOperand &SrcRegOp = DestSrc->Source;
+  if (!SrcRegOp.isKill() || !DestRegOp.isDef())
     return;
 
   auto isCalleeSavedReg = [&](unsigned Reg) {
@@ -1010,8 +1014,8 @@ void LiveDebugValues::transferRegisterCopy(MachineInstr &MI,
     return false;
   };
 
-  Register SrcReg = SrcRegOp->getReg();
-  Register DestReg = DestRegOp->getReg();
+  Register SrcReg = SrcRegOp.getReg();
+  Register DestReg = DestRegOp.getReg();
 
   // We want to recognize instructions where destination register is callee
   // saved register. If register that could be clobbered by the call is
diff --git a/llvm/lib/CodeGen/TargetInstrInfo.cpp b/llvm/lib/CodeGen/TargetInstrInfo.cpp
index 88fbfcb7784..f5f53b50ab8 100644
--- a/llvm/lib/CodeGen/TargetInstrInfo.cpp
+++ b/llvm/lib/CodeGen/TargetInstrInfo.cpp
@@ -1124,14 +1124,13 @@ Optional<ParamLoadedValue>
 TargetInstrInfo::describeLoadedValue(const MachineInstr &MI) const {
   const MachineFunction *MF = MI.getMF();
   DIExpression *Expr = DIExpression::get(MF->getFunction().getContext(), {});
-  const MachineOperand *SrcRegOp, *DestRegOp;
   int64_t Offset;
 
-  if (isCopyInstr(MI, SrcRegOp, DestRegOp)) {
-    return ParamLoadedValue(*SrcRegOp, Expr);
-  } else if (isAddImmediate(MI, DestRegOp, SrcRegOp, Offset)) {
+  if (auto DestSrc = isCopyInstr(MI)) {
+    return ParamLoadedValue(DestSrc->Source, Expr);
+  } else if (auto DestSrc = isAddImmediate(MI, Offset)) {
     Expr = DIExpression::prepend(Expr, DIExpression::ApplyOffset, Offset);
-    return ParamLoadedValue(*SrcRegOp, Expr);
+    return ParamLoadedValue(DestSrc->Source, Expr);
   }
 
   return None;