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, 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 *bzeroEntry = 29 (V && V->isNullValue()) ? STI.getBZeroEntry() : nullptr; 30 // For small size (< 256), it is not beneficial to use bzero 31 // instead of memset. 32 if (bzeroEntry && (!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).setChain(Chain) 46 .setCallee(CallingConv::C, Type::getVoidTy(*DAG.getContext()), 47 DAG.getExternalSymbol(bzeroEntry, IntPtr), std::move(Args), 0) 48 .setDiscardResult(); 49 std::pair<SDValue, SDValue> CallResult = TLI.LowerCallTo(CLI); 50 return CallResult.second; 51 } 52 return SDValue(); 53 } 54
