Subzero: Decorate the text asm output with register availability info.

src/IceTargetLowering.h

 //===- subzero/src/IceTargetLowering.h - Lowering interface -----*- 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 the TargetLowering and LoweringContext
@@ skipping 135 matching lines @@
   // Lowers a list of "parallel" assignment instructions representing
   // a topological sort of the Phi instructions.
   virtual void lowerPhiAssignments(CfgNode *Node,
                                    const AssignList &Assignments) = 0;
   // Tries to do branch optimization on a single instruction.  Returns
   // true if some optimization was done.
   virtual bool doBranchOpt(Inst * /*I*/, const CfgNode * /*NextNode*/) {
     return false;
   }
 
+  virtual SizeT getNumRegisters() const = 0;
   // Returns a variable pre-colored to the specified physical
   // register.  This is generally used to get very direct access to
   // the register such as in the prolog or epilog or for marking
   // scratch registers as killed by a call.  If a Type is not
   // provided, a target-specific default type is used.
   virtual Variable *getPhysicalRegister(SizeT RegNum,
                                         Type Ty = IceType_void) = 0;
   // Returns a printable name for the register.
   virtual IceString getRegName(SizeT RegNum, Type Ty) const = 0;
 
@@ skipping 102 matching lines @@
   virtual void lower(const VariableDeclaration &Var) = 0;
 
 protected:
   TargetGlobalInitLowering(GlobalContext *Ctx) : Ctx(Ctx) {}
   GlobalContext *Ctx;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERING_H