[RegisterScavenger] Fix debug print

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@338231 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/RegisterScavenging.cpp b/lib/CodeGen/RegisterScavenging.cpp
index a878c34..3660586 100644 (file)
--- a/lib/CodeGen/RegisterScavenging.cpp
+++ b/lib/CodeGen/RegisterScavenging.cpp
@@ -594,7 +594,8 @@ unsigned RegScavenger::scavengeRegisterBackwards(const TargetRegisterClass &RC,
     MachineBasicBlock::iterator ReloadAfter =
       RestoreAfter ? std::next(MBBI) : MBBI;
     MachineBasicBlock::iterator ReloadBefore = std::next(ReloadAfter);
-    LLVM_DEBUG(dbgs() << "Reload before: " << *ReloadBefore << '\n');
+    if (ReloadBefore != MBB.end())
+      LLVM_DEBUG(dbgs() << "Reload before: " << *ReloadBefore << '\n');
     ScavengedInfo &Scavenged = spill(Reg, RC, SPAdj, SpillBefore, ReloadBefore);
     Scavenged.Restore = &*std::prev(SpillBefore);
     LiveUnits.removeReg(Reg);