1 files changed, 16 insertions, 0 deletions

diff --git a/contrib/llvm/lib/CodeGen/MachineLoopInfo.cpp b/contrib/llvm/lib/CodeGen/MachineLoopInfo.cpp
index fdeaf7b71161..a9aa1d954e70 100644
--- a/contrib/llvm/lib/CodeGen/MachineLoopInfo.cpp
+++ b/contrib/llvm/lib/CodeGen/MachineLoopInfo.cpp
@@ -87,6 +87,22 @@ MachineBasicBlock *MachineLoop::findLoopControlBlock() {
   return nullptr;
 }
 
+DebugLoc MachineLoop::getStartLoc() const {
+  // Try the pre-header first.
+  if (MachineBasicBlock *PHeadMBB = getLoopPreheader())
+    if (const BasicBlock *PHeadBB = PHeadMBB->getBasicBlock())
+      if (DebugLoc DL = PHeadBB->getTerminator()->getDebugLoc())
+        return DL;
+
+  // If we have no pre-header or there are no instructions with debug
+  // info in it, try the header.
+  if (MachineBasicBlock *HeadMBB = getHeader())
+    if (const BasicBlock *HeadBB = HeadMBB->getBasicBlock())
+      return HeadBB->getTerminator()->getDebugLoc();
+
+  return DebugLoc();
+}
+
 MachineBasicBlock *
 MachineLoopInfo::findLoopPreheader(MachineLoop *L,
                                    bool SpeculativePreheader) const {