[NFC][Outliner] Delete default ctors for Candidate & OutlinedFunction.

I think it's good practice to avoid having default ctors unless they're really
valid/useful. For OutlinedFunction the default ctor was used to represent a
bail-out value for getOutliningCandidateInfo(), so I changed the API to return
an optional<getOutliningCandidateInfo> instead which seems a tad cleaner.

Differential Revision: https://reviews.llvm.org/D146375

1 files changed, 5 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/MachineOutliner.cpp b/llvm/lib/CodeGen/MachineOutliner.cpp
index 856b9bf..8d72208 100644
--- a/llvm/lib/CodeGen/MachineOutliner.cpp
+++ b/llvm/lib/CodeGen/MachineOutliner.cpp
@@ -655,21 +655,21 @@ void MachineOutliner::findCandidates(
     const TargetInstrInfo *TII =
         CandidatesForRepeatedSeq[0].getMF()->getSubtarget().getInstrInfo();
 
-    OutlinedFunction OF =
+    std::optional<OutlinedFunction> OF =
         TII->getOutliningCandidateInfo(CandidatesForRepeatedSeq);
 
     // If we deleted too many candidates, then there's nothing worth outlining.
     // FIXME: This should take target-specified instruction sizes into account.
-    if (OF.Candidates.size() < 2)
+    if (!OF || OF->Candidates.size() < 2)
       continue;
 
     // Is it better to outline this candidate than not?
-    if (OF.getBenefit() < 1) {
-      emitNotOutliningCheaperRemark(StringLen, CandidatesForRepeatedSeq, OF);
+    if (OF->getBenefit() < 1) {
+      emitNotOutliningCheaperRemark(StringLen, CandidatesForRepeatedSeq, *OF);
       continue;
     }
 
-    FunctionList.push_back(OF);
+    FunctionList.push_back(*OF);
   }
 }