Merge .debug_loc entries whenever possible to reduce debug_loc size.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124904 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.h b/lib/CodeGen/AsmPrinter/DwarfDebug.h
index 6a01e4b..7df0510 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.h
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.h
@@ -74,6 +74,28 @@
   MCSymbol *getLabel() const { return Label; }
 };
 
+/// DotDebugLocEntry - This struct describes location entries emitted in
+/// .debug_loc section.
+typedef struct DotDebugLocEntry {
+  const MCSymbol *Begin;
+  const MCSymbol *End;
+  MachineLocation Loc;
+  bool Merged;
+  DotDebugLocEntry() : Begin(0), End(0), Merged(false) {}
+  DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, MachineLocation &L) 
+    : Begin(B), End(E), Loc(L), Merged(false) {}
+  /// Empty entries are also used as a trigger to emit temp label. Such
+  /// labels are referenced is used to find debug_loc offset for a given DIE.
+  bool isEmpty() { return Begin == 0 && End == 0; }
+  bool isMerged() { return Merged; }
+  void Merge(DotDebugLocEntry *Next) {
+    if (!(Begin && Loc == Next->Loc && End == Next->Begin))
+      return;
+    Next->Begin = Begin;
+    Merged = true;
+  }
+} DotDebugLocEntry;
+
 class DwarfDebug {
   /// Asm - Target of Dwarf emission.
   AsmPrinter *Asm;
@@ -153,20 +175,6 @@
   /// machine instruction.
   DenseMap<const DbgVariable *, const MachineInstr *> DbgVariableToDbgInstMap;
 
-  /// DotDebugLocEntry - This struct describes location entries emitted in
-  /// .debug_loc section.
-  typedef struct DotDebugLocEntry {
-    const MCSymbol *Begin;
-    const MCSymbol *End;
-    MachineLocation Loc;
-    DotDebugLocEntry() : Begin(0), End(0) {}
-    DotDebugLocEntry(const MCSymbol *B, const MCSymbol *E, 
-                  MachineLocation &L) : Begin(B), End(E), Loc(L) {}
-    /// Empty entries are also used as a trigger to emit temp label. Such
-    /// labels are referenced is used to find debug_loc offset for a given DIE.
-    bool isEmpty() { return Begin == 0 && End == 0; }
-  } DotDebugLocEntry;
-
   /// DotDebugLocEntries - Collection of DotDebugLocEntry.
   SmallVector<DotDebugLocEntry, 4> DotDebugLocEntries;