Change representation of instruction ranges where variable is accessible.
Use more straightforward way to represent the set of instruction
ranges where the location of a user variable is defined - vector of pairs
of instructions (defining start/end of each range),
instead of a flattened vector of instructions where some instructions
are supposed to start the range, and the rest are supposed to "clobber" it.
Simplify the code which generates actual .debug_loc entries.
No functionality change.
llvm-svn: 209698
diff --git a/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h b/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
index db5116d..b9177f0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
+++ b/llvm/lib/CodeGen/AsmPrinter/DbgValueHistoryCalculator.h
@@ -20,12 +20,31 @@
class MDNode;
class TargetRegisterInfo;
-// For each user variable, keep a list of DBG_VALUE instructions for it
-// in the order of appearance. The list can also contain another
-// instructions, which are assumed to 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.
+ typedef std::pair<const MachineInstr *, const MachineInstr *> InstrRange;
+ typedef SmallVector<InstrRange, 4> InstrRanges;
+ typedef MapVector<const MDNode *, InstrRanges> InstrRangesMap;
+ 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,