commit 3842b94c4e7292de5f9e368bd60c64fc084c1bbe
author Simon Pilgrim <llvm-dev@redking.me.uk> Thu Oct 31 17:58:15 2019 +0000
committer Simon Pilgrim <llvm-dev@redking.me.uk> Thu Oct 31 18:00:29 2019 +0000
tree cd3c53f5d0df19bd7cea8da654ec063498fdbfaa
parent 05a2d70d963b83f1ed68eddd91b017b5f0a0fa72

Revert rG57ee0435bd47f23f3939f402914c231b4f65ca5e - [TII] Use optional destination and source pair as a return value; NFC

This is breaking MSVC builds: http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/20375

llvm/lib/CodeGen/LiveDebugValues.cpp

diff --git a/llvm/lib/CodeGen/LiveDebugValues.cpp b/llvm/lib/CodeGen/LiveDebugValues.cpp
index d38840b..b15c594 100644
--- a/llvm/lib/CodeGen/LiveDebugValues.cpp
+++ b/llvm/lib/CodeGen/LiveDebugValues.cpp
@@ -997,14 +997,10 @@
                                            OpenRangesSet &OpenRanges,
                                            VarLocMap &VarLocIDs,
                                            TransferMap &Transfers) {
+  const MachineOperand *SrcRegOp, *DestRegOp;
 
-  auto DestSrc = TII->isCopyInstr(MI);
-  if (!DestSrc)
-    return;
-
-  const MachineOperand &DestRegOp = DestSrc->Destination;
-  const MachineOperand &SrcRegOp = DestSrc->Source;
-  if (!SrcRegOp.isKill() || !DestRegOp.isDef())
+  if (!TII->isCopyInstr(MI, SrcRegOp, DestRegOp) || !SrcRegOp->isKill() ||
+      !DestRegOp->isDef())
     return;
 
   auto isCalleeSavedReg = [&](unsigned Reg) {
@@ -1014,8 +1010,8 @@
     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