Subzero: Initial O2 lowering

src/IceDefs.h

 //===- subzero/src/IceDefs.h - Common Subzero declaraions -------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares various useful types and classes that have
@@ skipping 32 matching lines @@
 
 namespace Ice {
 
 class Cfg;
 class CfgNode;
 class Constant;
 class GlobalContext;
 class Inst;
 class InstPhi;
 class InstTarget;
+class LiveRange;
+class Liveness;
 class Operand;
 class TargetLowering;
 class Variable;
 
 // TODO: Switch over to LLVM's ADT container classes.
 // http://llvm.org/docs/ProgrammersManual.html#picking-the-right-data-structure-for-a-task
 typedef std::string IceString;
 typedef std::list<Inst *> InstList;
 typedef std::list<InstPhi *> PhiList;
 typedef std::vector<Variable *> VarList;
 typedef std::vector<CfgNode *> NodeList;
 typedef std::vector<Constant *> ConstantList;
 
 // SizeT is for holding small-ish limits like number of source
 // operands in an instruction.  It is used instead of size_t (which
 // may be 64-bits wide) when we want to save space.
 typedef uint32_t SizeT;
 
+// InstNumberT is for holding an instruction number.  Instruction
+// numbers are used for representing Variable live ranges.
+typedef int32_t InstNumberT;
+
+enum LivenessMode {
+  // Basic version of live-range-end calculation.  Marks the last uses
+  // of variables based on dataflow analysis.  Records the set of
+  // live-in and live-out variables for each block.  Identifies and
+  // deletes dead instructions (primarily stores).
+  Liveness_Basic,
+
+  // In addition to Liveness_Basic, also calculate the complete
+  // live range for each variable in a form suitable for interference
+  // calculation and register allocation.
+  Liveness_Intervals
+};
+
 enum VerboseItem {
   IceV_None = 0,
   IceV_Instructions = 1 << 0,
   IceV_Deleted = 1 << 1,
   IceV_InstNumbers = 1 << 2,
   IceV_Preds = 1 << 3,
   IceV_Succs = 1 << 4,
   IceV_Liveness = 1 << 5,
   IceV_RegManager = 1 << 6,
   IceV_RegOrigins = 1 << 7,
@@ skipping 40 matching lines @@
 
 private:
   const llvm::TimeRecord Start;
   Timer(const Timer &) LLVM_DELETED_FUNCTION;
   Timer &operator=(const Timer &) LLVM_DELETED_FUNCTION;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEDEFS_H