Don't pre-populate the set of keys in the map with variable locations history.

Current implementation of calculateDbgValueHistory already creates the
keys in the expected order (user variables are listed in order of appearance),
and should do so later by contract.

No functionality change.

llvm-svn: 209690

2 files changed, 3 insertions, 11 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp b/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
index c9bf1ecf907..450d1541384 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.cpp
@@ -144,6 +144,7 @@ void calculateDbgValueHistory(const MachineFunction *MF,
         continue;
       }
 
+      assert(MI.getNumOperands() > 1 && "Invalid DBG_VALUE instruction!");
       const MDNode *Var = MI.getDebugVariable();
       auto &History = Result[Var];
 
diff --git a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 967c7b1b596..dad44b84a15 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -1404,17 +1404,8 @@ void DwarfDebug::beginFunction(const MachineFunction *MF) {
   // Collect user variables, find the end of the prologue.
   for (const auto &MBB : *MF) {
     for (const auto &MI : MBB) {
-      if (MI.isDebugValue()) {
-        assert(MI.getNumOperands() > 1 && "Invalid machine instruction!");
-        // Keep track of user variables in order of appearance. Create the
-        // empty history for each variable so that the order of keys in
-        // DbgValues is correct. Actual history will be populated in
-        // calculateDbgValueHistory() function.
-        const MDNode *Var = MI.getDebugVariable();
-        DbgValues.insert(
-            std::make_pair(Var, SmallVector<const MachineInstr *, 4>()));
-      } else if (!MI.getFlag(MachineInstr::FrameSetup) &&
-                 PrologEndLoc.isUnknown() && !MI.getDebugLoc().isUnknown()) {
+      if (!MI.isDebugValue() && !MI.getFlag(MachineInstr::FrameSetup) &&
+          PrologEndLoc.isUnknown() && !MI.getDebugLoc().isUnknown()) {
         // First known non-DBG_VALUE and non-frame setup location marks
         // the beginning of the function body.
         PrologEndLoc = MI.getDebugLoc();