X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FAsmPrinter%2FDbgValueHistoryCalculator.h;h=4b6200717d26721845675f9b4b01b1b7a4617daa;hb=f6456a560c2d483608372890ac125d79ba7572e2;hp=2945c1522de3a20163a99a160bd6ae7bc2918fae;hpb=5c91f4db1f5229b8e933c49d91e93c2bc7a6e4d9;p=oota-llvm.git

diff --git a/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h b/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
index 2945c1522de..4b6200717d2 100644
--- a/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
+++ b/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
@@ -7,8 +7,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H_
-#define CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H_
+#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H
+#define LLVM_LIB_CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H
 
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SmallVector.h"
@@ -20,11 +20,33 @@ class MachineInstr;
 class MDNode;
 class TargetRegisterInfo;
 
-// For each user variable, keep a list of DBG_VALUE instructions in order.
-// The list can also contain normal instructions that clobber the previous
-// DBG_VALUE. The variables are listed in order of appearance.
-typedef MapVector<const MDNode *, SmallVector<const MachineInstr *, 4>>
-DbgValueHistoryMap;
+// For each user variable, keep a list of instruction ranges where this variable
+// is accessible. The variables are listed in order of appearance.
+class DbgValueHistoryMap {
+  // Each instruction range starts with a DBG_VALUE instruction, specifying the
+  // location of a variable, which is assumed to be valid until the end of the
+  // range. If end is not specified, location is valid until the start
+  // instruction of the next instruction range, or until the end of the
+  // function.
+public:
+  typedef std::pair<const MachineInstr *, const MachineInstr *> InstrRange;
+  typedef SmallVector<InstrRange, 4> InstrRanges;
+  typedef MapVector<const MDNode *, InstrRanges> InstrRangesMap;
+private:
+  InstrRangesMap VarInstrRanges;
+
+public:
+  void startInstrRange(const MDNode *Var, const MachineInstr &MI);
+  void endInstrRange(const MDNode *Var, const MachineInstr &MI);
+  // Returns register currently describing @Var. If @Var is currently
+  // unaccessible or is not described by a register, returns 0.
+  unsigned getRegisterForVar(const MDNode *Var) const;
+
+  bool empty() const { return VarInstrRanges.empty(); }
+  void clear() { VarInstrRanges.clear(); }
+  InstrRangesMap::const_iterator begin() const { return VarInstrRanges.begin(); }
+  InstrRangesMap::const_iterator end() const { return VarInstrRanges.end(); }
+};
 
 void calculateDbgValueHistory(const MachineFunction *MF,
                               const TargetRegisterInfo *TRI,