Subzero: Make the register allocator more robust with -reg-use and -reg-exclude.

src/IceRegAlloc.h

 //===- subzero/src/IceRegAlloc.h - Linear-scan reg. allocation --*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 43 matching lines @@
     IterationState(const IterationState &) = delete;
     IterationState operator=(const IterationState &) = delete;
 
   public:
     IterationState() = default;
     Variable *Cur = nullptr;
     Variable *Prefer = nullptr;
     int32_t PreferReg = Variable::NoRegister;
     bool AllowOverlap = false;
     llvm::SmallBitVector RegMask;
+    llvm::SmallBitVector RegMaskUnfiltered;
     llvm::SmallBitVector Free;
+    llvm::SmallBitVector FreeUnfiltered;
     llvm::SmallBitVector PrecoloredUnhandledMask; // Note: only used for dumping
     llvm::SmallVector<RegWeight, REGS_SIZE> Weights;
   };
 
   bool livenessValidateIntervals(const DefUseErrorList &DefsWithoutUses,
                                  const DefUseErrorList &UsesBeforeDefs,
                                  const CfgVector<InstNumberT> &LRBegin,
                                  const CfgVector<InstNumberT> &LREnd) const;
   void initForGlobal();
   void initForInfOnly();
@@ skipping 16 matching lines @@
   void addSpillFill(IterationState &Iter);
   /// Check for active ranges that have expired or become inactive.
   void handleActiveRangeExpiredOrInactive(const Variable *Cur);
   /// Check for inactive ranges that have expired or reactivated.
   void handleInactiveRangeExpiredOrReactivated(const Variable *Cur);
   void findRegisterPreference(IterationState &Iter);
   void filterFreeWithInactiveRanges(IterationState &Iter);
   void filterFreeWithPrecoloredRanges(IterationState &Iter);
   void allocatePrecoloredRegister(Variable *Cur);
   void allocatePreferredRegister(IterationState &Iter);
-  void allocateFreeRegister(IterationState &Iter);
+  void allocateFreeRegister(IterationState &Iter, bool Filtered);
   void handleNoFreeRegisters(IterationState &Iter);
   void assignFinalRegisters(const llvm::SmallBitVector &RegMaskFull,
                             const llvm::SmallBitVector &PreDefinedRegisters,
                             bool Randomized);
   /// @}
 
   void dumpLiveRangeTrace(const char *Label, const Variable *Item);
 
   Cfg *const Func;
   GlobalContext *const Ctx;
@@ skipping 11 matching lines @@
   /// currently assigned to. It can be greater than 1 as a result of
   /// AllowOverlap inference.
   llvm::SmallVector<int32_t, REGS_SIZE> RegUses;
   // TODO(jpp): for some architectures a SmallBitVector might not be big
   // enough. Evaluate what the performance impact on those architectures is.
   llvm::SmallVector<const llvm::SmallBitVector *, REGS_SIZE> RegAliases;
   bool FindPreference = false;
   bool FindOverlap = false;
 
   const bool Verbose;
+  const bool UseReserve;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEREGALLOC_H