[MachineOutliner] Exit getOutliningCandidateInfo when we erase all candidates

There was a missing check for if a candidate list was entirely deleted. This
adds that check.

This fixes an asan failure caused by running test/CodeGen/AArch64/addsub_ext.ll
with the MachineOutliner enabled.

llvm-svn: 338148

1 files changed, 4 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
index dc3fa4f8c1d..230480cf1ce 100644
--- a/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
@@ -4967,6 +4967,10 @@ AArch64InstrInfo::getOutliningCandidateInfo(
                                             CantGuaranteeValueAcrossCall),
                              RepeatedSequenceLocs.end());
 
+  // If the sequence is empty, we're done.
+  if (RepeatedSequenceLocs.empty())
+    return outliner::OutlinedFunction();
+
   // At this point, we have only "safe" candidates to outline. Figure out
   // frame + call instruction information.