Cleanup collectChangingRegs

The handling of the epilogue is best expressed as an early exit and
there is no reason to look for register defs in DbgValue MIs.

Patch by Frederic Riss!

llvm-svn: 214986

1 files changed, 4 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp b/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
index f557ccddb47..143b0135c8c 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
@@ -152,10 +152,11 @@ static void collectChangingRegs(const MachineFunction *MF,
                                 std::set<unsigned> &Regs) {
   for (const auto &MBB : *MF) {
     auto FirstEpilogueInst = getFirstEpilogueInst(MBB);
-    bool IsInEpilogue = false;
+
     for (const auto &MI : MBB) {
-      IsInEpilogue |= &MI == FirstEpilogueInst;
-      if (!MI.getFlag(MachineInstr::FrameSetup) && !IsInEpilogue)
+      if (&MI == FirstEpilogueInst)
+        break;
+      if (!MI.getFlag(MachineInstr::FrameSetup))
         collectClobberedRegisters(MI, TRI, Regs);
     }
   }