Add a new "NewDebugLoc" class which will eventually replace DebugLoc,

and will replace the 'DbgInfo' member in Instruction.

The benefit of NewDebugLoc is that it is compact (8 bytes vs 12/24 
bytes for the DbgInfo member in Instruction on a 32/64 bit system),
it means that we will end up not having to allocate MDNodes to 
represent the "DILocations" in common cases of -O0 -g, and it is
much more efficient to get things out of than the MDNode.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@100072 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/DebugLoc.h

@@ -20,6 +20,61 @@
 
 namespace llvm {
   class MDNode;
+  class LLVMContext;
+  
+  /// DebugLoc - Debug location id.  This is carried by Instruction, SDNode,
+  /// and MachineInstr to compactly encode file/line/scope information for an
+  /// operation.
+  class NewDebugLoc {
+    /// LineCol - This 32-bit value encodes the line and column number for the
+    /// location, encoded as 24-bits for line and 8 bits for col.  A value of 0
+    /// for either means unknown.
+    unsigned LineCol;
+    
+    /// ScopeIdx - This is an opaque ID# for Scope/InlinedAt information,
+    /// decoded by LLVMContext.  0 is unknown.
+    int ScopeIdx;
+  public:
+    NewDebugLoc() : LineCol(0), ScopeIdx(0) {}  // Defaults to unknown.
+    
+    static NewDebugLoc get(unsigned Line, unsigned Col,
+                           MDNode *Scope, MDNode *InlinedAt);
+    
+    /// isUnknown - Return true if this is an unknown location.
+    bool isUnknown() const { return ScopeIdx == 0; }
+    
+    unsigned getLine() const {
+      return (LineCol << 8) >> 8;  // Mask out column.
+    }
+    
+    unsigned getCol() const {
+      return LineCol >> 24;
+    }
+    
+    /// getScope - This returns the scope pointer for this DebugLoc, or null if
+    /// invalid.
+    MDNode *getScope(const LLVMContext &Ctx) const;
+    
+    /// getInlinedAt - This returns the InlinedAt pointer for this DebugLoc, or
+    /// null if invalid or not present.
+    MDNode *getInlinedAt(const LLVMContext &Ctx) const;
+    
+    /// getScopeAndInlinedAt - Return both the Scope and the InlinedAt values.
+    void getScopeAndInlinedAt(MDNode *&Scope, MDNode *&IA,
+                              const LLVMContext &Ctx) const;
+    
+    
+    /// getAsMDNode - This method converts the compressed DebugLoc node into a
+    /// DILocation compatible MDNode.
+    MDNode *getAsMDNode(const LLVMContext &Ctx) const;
+    
+    bool operator==(const NewDebugLoc &DL) const {
+      return LineCol == DL.LineCol && ScopeIdx == DL.ScopeIdx;
+    }
+    bool operator!=(const NewDebugLoc &DL) const { return !(*this == DL); }
+  };
+  
+  
 
   /// DebugLoc - Debug location id. This is carried by SDNode and MachineInstr
   /// to index into a vector of unique debug location tuples.