Inline memset when there is a constant value and count.

src/IceTargetLoweringX86Base.h

 //===- subzero/src/IceTargetLoweringX86Base.h - x86 lowering ----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 140 matching lines @@
   /// Naive lowering of cmpxchg.
   void lowerAtomicCmpxchg(Variable *DestPrev, Operand *Ptr, Operand *Expected,
                           Operand *Desired);
   /// Attempt a more optimized lowering of cmpxchg. Returns true if optimized.
   bool tryOptimizedCmpxchgCmpBr(Variable *DestPrev, Operand *Ptr,
                                 Operand *Expected, Operand *Desired);
   void lowerAtomicRMW(Variable *Dest, uint32_t Operation, Operand *Ptr,
                       Operand *Val);
   void lowerCountZeros(bool Cttz, Type Ty, Variable *Dest, Operand *FirstVal,
                        Operand *SecondVal);
+  /// Replace a function call with inline instructions.
+  void lowerMemset(Operand *Dest, Operand *Val, Operand *Count);
+
   /// Lower an indirect jump adding sandboxing when needed.
   void lowerIndirectJump(Variable *Target);
 
   /// Check the comparison is in [Min,Max]. The flags register will be modified
   /// with:
   ///   - below equal, if in range
   ///   - above, set if not in range
   /// The index into the range is returned.
   Operand *lowerCmpRange(Operand *Comparison, uint64_t Min, uint64_t Max);
   /// Lowering of a cluster of switch cases. If the case is not matched control
@@ skipping 36 matching lines @@
   /// used by a real load/store operation. Legalizes the operand as well.
   /// This is a nop if the operand is already a legal memory operand.
   typename Traits::X86OperandMem *formMemoryOperand(Operand *Ptr, Type Ty,
                                                     bool DoLegalize = true);
 
   Variable *makeReg(Type Ty, int32_t RegNum = Variable::NoRegister);
   static Type stackSlotType();
 
   Variable *copyToReg(Operand *Src, int32_t RegNum = Variable::NoRegister);
 
-  /// Returns a vector in a register with the given constant entries.
+  /// \name Returns a vector in a register with the given constant entries.
+  /// @{
   Variable *makeVectorOfZeros(Type Ty, int32_t RegNum = Variable::NoRegister);
   Variable *makeVectorOfOnes(Type Ty, int32_t RegNum = Variable::NoRegister);
   Variable *makeVectorOfMinusOnes(Type Ty,
                                   int32_t RegNum = Variable::NoRegister);
   Variable *makeVectorOfHighOrderBits(Type Ty,
                                       int32_t RegNum = Variable::NoRegister);
   Variable *makeVectorOfFabsMask(Type Ty,
                                  int32_t RegNum = Variable::NoRegister);
+  /// @}
 
   /// Return a memory operand corresponding to a stack allocated Variable.
   typename Traits::X86OperandMem *
   getMemoryOperandForStackSlot(Type Ty, Variable *Slot, uint32_t Offset = 0);
 
   void makeRandomRegisterPermutation(
       llvm::SmallVectorImpl<int32_t> &Permutation,
       const llvm::SmallBitVector &ExcludeRegisters) const override;
 
   /// The following are helpers that insert lowered x86 instructions
@@ skipping 386 matching lines @@
   }
 
   BoolFolding FoldingInfo;
 };
 } // end of namespace X86Internal
 } // end of namespace Ice
 
 #include "IceTargetLoweringX86BaseImpl.h"
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX86BASE_H