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!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214986 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp b/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
index f557ccddb47dce36380f60cffc7e83fca9c8cf93..143b0135c8c8432c3b233ac355765683fb762cb4 100644 (file)
--- a/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
+++ b/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);
     }
   }