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      1 //===-- AArch64SelectionDAGInfo.cpp - AArch64 SelectionDAG Info -----------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file implements the AArch64SelectionDAGInfo class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "AArch64TargetMachine.h"
     15 using namespace llvm;
     16 
     17 #define DEBUG_TYPE "aarch64-selectiondag-info"
     18 
     19 SDValue AArch64SelectionDAGInfo::EmitTargetCodeForMemset(
     20     SelectionDAG &DAG, const SDLoc &dl, SDValue Chain, SDValue Dst, SDValue Src,
     21     SDValue Size, unsigned Align, bool isVolatile,
     22     MachinePointerInfo DstPtrInfo) const {
     23   // Check to see if there is a specialized entry-point for memory zeroing.
     24   ConstantSDNode *V = dyn_cast<ConstantSDNode>(Src);
     25   ConstantSDNode *SizeValue = dyn_cast<ConstantSDNode>(Size);
     26   const AArch64Subtarget &STI =
     27       DAG.getMachineFunction().getSubtarget<AArch64Subtarget>();
     28   const char *bzeroName = (V && V->isNullValue())
     29       ? DAG.getTargetLoweringInfo().getLibcallName(RTLIB::BZERO) : nullptr;
     30   // For small size (< 256), it is not beneficial to use bzero
     31   // instead of memset.
     32   if (bzeroName && (!SizeValue || SizeValue->getZExtValue() > 256)) {
     33     const AArch64TargetLowering &TLI = *STI.getTargetLowering();
     34 
     35     EVT IntPtr = TLI.getPointerTy(DAG.getDataLayout());
     36     Type *IntPtrTy = DAG.getDataLayout().getIntPtrType(*DAG.getContext());
     37     TargetLowering::ArgListTy Args;
     38     TargetLowering::ArgListEntry Entry;
     39     Entry.Node = Dst;
     40     Entry.Ty = IntPtrTy;
     41     Args.push_back(Entry);
     42     Entry.Node = Size;
     43     Args.push_back(Entry);
     44     TargetLowering::CallLoweringInfo CLI(DAG);
     45     CLI.setDebugLoc(dl)
     46         .setChain(Chain)
     47         .setLibCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()),
     48                       DAG.getExternalSymbol(bzeroName, IntPtr),
     49                       std::move(Args))
     50         .setDiscardResult();
     51     std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI);
     52     return CallResult.second;
     53   }
     54   return SDValue();
     55 }
     56 bool AArch64SelectionDAGInfo::generateFMAsInMachineCombiner(
     57     CodeGenOpt::Level OptLevel) const {
     58   return OptLevel >= CodeGenOpt::Aggressive;
     59 }
     60