131d157ae1ac2cd9c787dc3c1d28e64c682803844Jia Liu//===-- Thumb1FrameLowering.cpp - Thumb1 Frame Information ----------------===// 233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// 333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// The LLVM Compiler Infrastructure 433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// 533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// This file is distributed under the University of Illinois Open Source 633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// License. See LICENSE.TXT for details. 733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// 833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov//===----------------------------------------------------------------------===// 933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// 1016c29b5f285f375be53dabaa73e3e91107485fe4Anton Korobeynikov// This file contains the Thumb1 implementation of TargetFrameLowering class. 1133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov// 1233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov//===----------------------------------------------------------------------===// 1333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 1416c29b5f285f375be53dabaa73e3e91107485fe4Anton Korobeynikov#include "Thumb1FrameLowering.h" 1533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov#include "ARMMachineFunctionInfo.h" 1633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov#include "llvm/CodeGen/MachineFrameInfo.h" 1733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov#include "llvm/CodeGen/MachineFunction.h" 1833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov#include "llvm/CodeGen/MachineInstrBuilder.h" 1936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines#include "llvm/CodeGen/MachineModuleInfo.h" 20ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng#include "llvm/CodeGen/MachineRegisterInfo.h" 2133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 2233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikovusing namespace llvm; 2333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 24cd81d94322a39503e4a3e87b6ee03d4fcb3465fbStephen HinesThumb1FrameLowering::Thumb1FrameLowering(const ARMSubtarget &sti) 25cd81d94322a39503e4a3e87b6ee03d4fcb3465fbStephen Hines : ARMFrameLowering(sti) {} 26cd81d94322a39503e4a3e87b6ee03d4fcb3465fbStephen Hines 27b04546ff5b1a7a03eec1076900c945223bf494ccJim Grosbachbool Thumb1FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const{ 28d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov const MachineFrameInfo *FFI = MF.getFrameInfo(); 29d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov unsigned CFSize = FFI->getMaxCallFrameSize(); 30d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov // It's not always a good idea to include the call frame as part of the 31d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov // stack frame. ARM (especially Thumb) has small immediate offset to 32d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov // address the stack frame. So a large call frame can cause poor codegen 33d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov // and may even makes it impossible to scavenge a register. 34d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov if (CFSize >= ((1 << 8) - 1) * 4 / 2) // Half of imm8 * 4 35d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov return false; 36d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov 37d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov return !MF.getFrameInfo()->hasVarSizedObjects(); 38d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov} 39d0c38176690e9602a93a20a43f1bd084564a8116Anton Korobeynikov 403daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikovstatic void 413daccd82d3151fa3629de430b55698a81084fc9eAnton KorobeynikovemitSPUpdate(MachineBasicBlock &MBB, 423daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov MachineBasicBlock::iterator &MBBI, 433daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov const TargetInstrInfo &TII, DebugLoc dl, 443daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov const Thumb1RegisterInfo &MRI, 453daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov int NumBytes, unsigned MIFlags = MachineInstr::NoFlags) { 4657caad7a33ff145b71545f10dcfbbf2fd0f595d3Anton Korobeynikov emitThumbRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes, TII, 473daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov MRI, MIFlags); 4833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov} 4933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 50700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky 51700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Benderskyvoid Thumb1FrameLowering:: 52700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli BenderskyeliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, 53700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky MachineBasicBlock::iterator I) const { 54700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky const Thumb1InstrInfo &TII = 55700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo()); 56700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky const Thumb1RegisterInfo *RegInfo = 57700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo()); 58700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky if (!hasReservedCallFrame(MF)) { 59700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky // If we have alloca, convert as follows: 60700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky // ADJCALLSTACKDOWN -> sub, sp, sp, amount 61700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky // ADJCALLSTACKUP -> add, sp, sp, amount 62700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky MachineInstr *Old = I; 63700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky DebugLoc dl = Old->getDebugLoc(); 64700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky unsigned Amount = Old->getOperand(0).getImm(); 65700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky if (Amount != 0) { 66700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky // We need to keep the stack aligned properly. To do this, we round the 67700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky // amount of space needed for the outgoing arguments up to the next 68700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky // alignment boundary. 69700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky unsigned Align = getStackAlignment(); 70700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky Amount = (Amount+Align-1)/Align*Align; 71700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky 72700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky // Replace the pseudo instruction with a new instruction... 73700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky unsigned Opc = Old->getOpcode(); 74700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) { 75700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky emitSPUpdate(MBB, I, TII, dl, *RegInfo, -Amount); 76700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky } else { 77700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP); 78700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky emitSPUpdate(MBB, I, TII, dl, *RegInfo, Amount); 79700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky } 80700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky } 81700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky } 82700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky MBB.erase(I); 83700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky} 84700ed80d3da5e98e05ceb90e9bfb66058581a6dbEli Bendersky 8516c29b5f285f375be53dabaa73e3e91107485fe4Anton Korobeynikovvoid Thumb1FrameLowering::emitPrologue(MachineFunction &MF) const { 8633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MachineBasicBlock &MBB = MF.front(); 8733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MachineBasicBlock::iterator MBBI = MBB.begin(); 8833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MachineFrameInfo *MFI = MF.getFrameInfo(); 8933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>(); 9036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MachineModuleInfo &MMI = MF.getMMI(); 9136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo(); 9233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov const Thumb1RegisterInfo *RegInfo = 9333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo()); 9433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov const Thumb1InstrInfo &TII = 9533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo()); 9633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 97083bc97344d618884ef04bc1ba1fc4ddf14d867dStepan Dyatkovskiy unsigned Align = MF.getTarget().getFrameLowering()->getStackAlignment(); 98083bc97344d618884ef04bc1ba1fc4ddf14d867dStepan Dyatkovskiy unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize(Align); 9933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned NumBytes = MFI->getStackSize(); 10036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines assert(NumBytes >= ArgRegsSaveSize && 10136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines "ArgRegsSaveSize is included in NumBytes"); 10233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo(); 10333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc(); 10433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned FramePtr = RegInfo->getFrameRegister(MF); 10533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned BasePtr = RegInfo->getBaseRegister(); 10636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines int CFAOffset = 0; 10733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 10833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4. 10933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov NumBytes = (NumBytes + 3) & ~3; 11033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MFI->setStackSize(NumBytes); 11133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 11233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Determine the sizes of each callee-save spill areas and record which frame 11333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // belongs to which callee-save spill areas. 11433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0; 11533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov int FramePtrSpillFI = 0; 11633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 11736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (ArgRegsSaveSize) { 118f65e4932f83ac0c36594d97fca73dc9a9fd26672Stepan Dyatkovskiy emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -ArgRegsSaveSize, 1193daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov MachineInstr::FrameSetup); 12036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines CFAOffset -= ArgRegsSaveSize; 12136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned CFIIndex = MMI.addFrameInst( 12236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset)); 12336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) 12436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines .addCFIIndex(CFIIndex); 12536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 12633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 12733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (!AFI->hasStackFrame()) { 12836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (NumBytes - ArgRegsSaveSize != 0) { 12936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -(NumBytes - ArgRegsSaveSize), 1303daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov MachineInstr::FrameSetup); 13136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines CFAOffset -= NumBytes - ArgRegsSaveSize; 13236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned CFIIndex = MMI.addFrameInst( 13336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset)); 13436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) 13536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines .addCFIIndex(CFIIndex); 13636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 13733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov return; 13833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 13933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 14033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov for (unsigned i = 0, e = CSI.size(); i != e; ++i) { 14133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned Reg = CSI[i].getReg(); 14233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov int FI = CSI[i].getFrameIdx(); 14333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov switch (Reg) { 14436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R8: 14536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R9: 14636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R10: 14736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R11: 14836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (STI.isTargetMachO()) { 14936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines GPRCS2Size += 4; 15036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines break; 15136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 15236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines // fallthrough 15333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov case ARM::R4: 15433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov case ARM::R5: 15533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov case ARM::R6: 15633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov case ARM::R7: 15733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov case ARM::LR: 15833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (Reg == FramePtr) 15933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov FramePtrSpillFI = FI; 16033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov GPRCS1Size += 4; 16133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov break; 16233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov default: 16333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov DPRCSSize += 8; 16433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 16533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 16633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 16733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) { 16833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov ++MBBI; 16933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (MBBI != MBB.end()) 17033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov dl = MBBI->getDebugLoc(); 17133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 17233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 17333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Determine starting offsets of spill areas. 17436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned DPRCSOffset = NumBytes - ArgRegsSaveSize - (GPRCS1Size + GPRCS2Size + DPRCSSize); 17533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize; 17633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size; 177af3a5420aeb421e83694745c53141683caa123cbLogan Chien bool HasFP = hasFP(MF); 178af3a5420aeb421e83694745c53141683caa123cbLogan Chien if (HasFP) 179af3a5420aeb421e83694745c53141683caa123cbLogan Chien AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + 180af3a5420aeb421e83694745c53141683caa123cbLogan Chien NumBytes); 18133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset); 18233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset); 18333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset); 18433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov NumBytes = DPRCSOffset; 185ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng 186323ac85d6ad7ba5d9593d8e151d879bd91d82e08Tim Northover int FramePtrOffsetInBlock = 0; 18736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned adjustedGPRCS1Size = GPRCS1Size; 18836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (tryFoldSPUpdateIntoPushPop(STI, MF, std::prev(MBBI), NumBytes)) { 189323ac85d6ad7ba5d9593d8e151d879bd91d82e08Tim Northover FramePtrOffsetInBlock = NumBytes; 19036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines adjustedGPRCS1Size += NumBytes; 191323ac85d6ad7ba5d9593d8e151d879bd91d82e08Tim Northover NumBytes = 0; 192323ac85d6ad7ba5d9593d8e151d879bd91d82e08Tim Northover } 193323ac85d6ad7ba5d9593d8e151d879bd91d82e08Tim Northover 19436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (adjustedGPRCS1Size) { 19536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines CFAOffset -= adjustedGPRCS1Size; 19636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned CFIIndex = MMI.addFrameInst( 19736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset)); 19836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) 19936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines .addCFIIndex(CFIIndex); 20036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 20136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(), 20236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines E = CSI.end(); I != E; ++I) { 20336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned Reg = I->getReg(); 20436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines int FI = I->getFrameIdx(); 20536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines switch (Reg) { 20636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R8: 20736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R9: 20836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R10: 20936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R11: 21036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R12: 21136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (STI.isTargetMachO()) 21236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines break; 21336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines // fallthough 21436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R0: 21536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R1: 21636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R2: 21736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R3: 21836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R4: 21936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R5: 22036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R6: 22136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::R7: 22236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines case ARM::LR: 22336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset( 22436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines nullptr, MRI->getDwarfRegNum(Reg, true), MFI->getObjectOffset(FI))); 22536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) 22636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines .addCFIIndex(CFIIndex); 22736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines break; 22836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 22936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 23036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 23136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines 232ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng // Adjust FP so it point to the stack slot that contains the previous FP. 233af3a5420aeb421e83694745c53141683caa123cbLogan Chien if (HasFP) { 23436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines FramePtrOffsetInBlock += MFI->getObjectOffset(FramePtrSpillFI) 23536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines + GPRCS1Size + ArgRegsSaveSize; 2365b81584f7403ffdb9cc6babaaeb0411c080e0f81Jim Grosbach AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr) 237323ac85d6ad7ba5d9593d8e151d879bd91d82e08Tim Northover .addReg(ARM::SP).addImm(FramePtrOffsetInBlock / 4) 2385b81584f7403ffdb9cc6babaaeb0411c080e0f81Jim Grosbach .setMIFlags(MachineInstr::FrameSetup)); 23936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if(FramePtrOffsetInBlock) { 24036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines CFAOffset += FramePtrOffsetInBlock; 24136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfa( 24236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines nullptr, MRI->getDwarfRegNum(FramePtr, true), CFAOffset)); 24336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) 24436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines .addCFIIndex(CFIIndex); 24536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } else { 24636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned CFIIndex = 24736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister( 24836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines nullptr, MRI->getDwarfRegNum(FramePtr, true))); 24936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) 25036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines .addCFIIndex(CFIIndex); 25136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 2527980f61f5ff408b947474cd1c3715896d28ea578Jim Grosbach if (NumBytes > 508) 2537980f61f5ff408b947474cd1c3715896d28ea578Jim Grosbach // If offset is > 508 then sp cannot be adjusted in a single instruction, 254ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng // try restoring from fp instead. 255ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng AFI->setShouldRestoreSPFromFP(true); 256ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng } 257ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng 25836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (NumBytes) { 25933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Insert it after all the callee-save spills. 2603daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes, 2613daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov MachineInstr::FrameSetup); 26236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (!HasFP) { 26336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines CFAOffset -= NumBytes; 26436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines unsigned CFIIndex = MMI.addFrameInst( 26536b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset)); 26636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION)) 26736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines .addCFIIndex(CFIIndex); 26836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 26936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } 27033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 271af3a5420aeb421e83694745c53141683caa123cbLogan Chien if (STI.isTargetELF() && HasFP) 27233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() - 27333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->getFramePtrSpillOffset()); 27433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 27533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->setGPRCalleeSavedArea1Size(GPRCS1Size); 27633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->setGPRCalleeSavedArea2Size(GPRCS2Size); 27733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->setDPRCalleeSavedAreaSize(DPRCSSize); 27833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 2796690bca623d1f6405b95db5b1760f7ba8436e3fbChad Rosier // Thumb1 does not currently support dynamic stack realignment. Report a 2806690bca623d1f6405b95db5b1760f7ba8436e3fbChad Rosier // fatal error rather then silently generate bad code. 2816690bca623d1f6405b95db5b1760f7ba8436e3fbChad Rosier if (RegInfo->needsStackRealignment(MF)) 2826690bca623d1f6405b95db5b1760f7ba8436e3fbChad Rosier report_fatal_error("Dynamic stack realignment not supported for thumb1."); 283d73462a1c9e9abae6d404c7830224814ef293f0dChad Rosier 28433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // If we need a base pointer, set it up here. It's whatever the value 28533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // of the stack pointer is at this point. Any variable size objects 28633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // will be allocated after this, so we can still use the base pointer 28733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // to reference locals. 28833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (RegInfo->hasBasePointer(MF)) 2892a7b41ba4d3eb3c6003f6768dc20b28d83eac265Jim Grosbach AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), BasePtr) 29063b46faeb8acae9b7e5f865b7417dc00b9b9dad3Jim Grosbach .addReg(ARM::SP)); 2913daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov 29294bb7b561c16878ae442adeb13dd42140b55d027Eric Christopher // If the frame has variable sized objects then the epilogue must restore 29394bb7b561c16878ae442adeb13dd42140b55d027Eric Christopher // the sp from fp. We can assume there's an FP here since hasFP already 29494bb7b561c16878ae442adeb13dd42140b55d027Eric Christopher // checks for hasVarSizedObjects. 29594bb7b561c16878ae442adeb13dd42140b55d027Eric Christopher if (MFI->hasVarSizedObjects()) 29694bb7b561c16878ae442adeb13dd42140b55d027Eric Christopher AFI->setShouldRestoreSPFromFP(true); 29733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov} 29833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 299dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hinesstatic bool isCSRestore(MachineInstr *MI, const MCPhysReg *CSRegs) { 30074472b4bf963c424da04f42dffdb94c85ef964bcJim Grosbach if (MI->getOpcode() == ARM::tLDRspi && 30133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MI->getOperand(1).isFI() && 30233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs)) 30333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov return true; 30433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov else if (MI->getOpcode() == ARM::tPOP) { 30533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // The first two operands are predicates. The last two are 30633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // imp-def and imp-use of SP. Check everything in between. 30733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov for (int i = 2, e = MI->getNumOperands() - 2; i != e; ++i) 30833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (!isCalleeSavedRegister(MI->getOperand(i).getReg(), CSRegs)) 30933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov return false; 31033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov return true; 31133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 31233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov return false; 31333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov} 31433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 31516c29b5f285f375be53dabaa73e3e91107485fe4Anton Korobeynikovvoid Thumb1FrameLowering::emitEpilogue(MachineFunction &MF, 31633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MachineBasicBlock &MBB) const { 3174f28c1c71450c711e96aa283de53739d8b4504cdJakob Stoklund Olesen MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr(); 31833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov assert((MBBI->getOpcode() == ARM::tBX_RET || 31933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MBBI->getOpcode() == ARM::tPOP_RET) && 32033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov "Can only insert epilog into returning blocks"); 32133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov DebugLoc dl = MBBI->getDebugLoc(); 32233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MachineFrameInfo *MFI = MF.getFrameInfo(); 32333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>(); 32433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov const Thumb1RegisterInfo *RegInfo = 32533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov static_cast<const Thumb1RegisterInfo*>(MF.getTarget().getRegisterInfo()); 32633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov const Thumb1InstrInfo &TII = 32733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov *static_cast<const Thumb1InstrInfo*>(MF.getTarget().getInstrInfo()); 32833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 329083bc97344d618884ef04bc1ba1fc4ddf14d867dStepan Dyatkovskiy unsigned Align = MF.getTarget().getFrameLowering()->getStackAlignment(); 330083bc97344d618884ef04bc1ba1fc4ddf14d867dStepan Dyatkovskiy unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize(Align); 33133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov int NumBytes = (int)MFI->getStackSize(); 33236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines assert((unsigned)NumBytes >= ArgRegsSaveSize && 33336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines "ArgRegsSaveSize is included in NumBytes"); 334dce4a407a24b04eebc6a376f8e62b41aaa7b071fStephen Hines const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegs(); 33533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov unsigned FramePtr = RegInfo->getFrameRegister(MF); 33633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 33733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (!AFI->hasStackFrame()) { 33836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (NumBytes - ArgRegsSaveSize != 0) 33936b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, NumBytes - ArgRegsSaveSize); 34033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } else { 34133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Unwind MBBI to point to first LDR / VLDRD. 34233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (MBBI != MBB.begin()) { 34333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov do 34433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov --MBBI; 34533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov while (MBBI != MBB.begin() && isCSRestore(MBBI, CSRegs)); 34633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (!isCSRestore(MBBI, CSRegs)) 34733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov ++MBBI; 34833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 34933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 35033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Move SP to start of FP callee save spill area. 35133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov NumBytes -= (AFI->getGPRCalleeSavedArea1Size() + 35233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AFI->getGPRCalleeSavedArea2Size() + 35336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines AFI->getDPRCalleeSavedAreaSize() + 35436b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines ArgRegsSaveSize); 35533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 35633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (AFI->shouldRestoreSPFromFP()) { 35733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov NumBytes = AFI->getFramePtrSpillOffset() - NumBytes; 35833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Reset SP based on frame pointer only if the stack frame extends beyond 35994bb7b561c16878ae442adeb13dd42140b55d027Eric Christopher // frame pointer stack slot, the target is ELF and the function has FP, or 36094bb7b561c16878ae442adeb13dd42140b55d027Eric Christopher // the target uses var sized objects. 361ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng if (NumBytes) { 362ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng assert(MF.getRegInfo().isPhysRegUsed(ARM::R4) && 363ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng "No scratch register to restore SP from FP!"); 36457caad7a33ff145b71545f10dcfbbf2fd0f595d3Anton Korobeynikov emitThumbRegPlusImmediate(MBB, MBBI, dl, ARM::R4, FramePtr, -NumBytes, 36557caad7a33ff145b71545f10dcfbbf2fd0f595d3Anton Korobeynikov TII, *RegInfo); 3662a7b41ba4d3eb3c6003f6768dc20b28d83eac265Jim Grosbach AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), 36763b46faeb8acae9b7e5f865b7417dc00b9b9dad3Jim Grosbach ARM::SP) 36863b46faeb8acae9b7e5f865b7417dc00b9b9dad3Jim Grosbach .addReg(ARM::R4)); 369ab5c703fdb0b07c6d89271519fd1cca7105b3eaeEvan Cheng } else 3702a7b41ba4d3eb3c6003f6768dc20b28d83eac265Jim Grosbach AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), 37163b46faeb8acae9b7e5f865b7417dc00b9b9dad3Jim Grosbach ARM::SP) 37263b46faeb8acae9b7e5f865b7417dc00b9b9dad3Jim Grosbach .addReg(FramePtr)); 37333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } else { 37433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov if (MBBI->getOpcode() == ARM::tBX_RET && 37533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov &MBB.front() != MBBI && 37636b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines std::prev(MBBI)->getOpcode() == ARM::tPOP) { 37736b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MachineBasicBlock::iterator PMBBI = std::prev(MBBI); 37836b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines if (!tryFoldSPUpdateIntoPushPop(STI, MF, PMBBI, NumBytes)) 379323ac85d6ad7ba5d9593d8e151d879bd91d82e08Tim Northover emitSPUpdate(MBB, PMBBI, TII, dl, *RegInfo, NumBytes); 38036b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines } else if (!tryFoldSPUpdateIntoPushPop(STI, MF, MBBI, NumBytes)) 38133464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, NumBytes); 38233464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 38333464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 38433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 385f65e4932f83ac0c36594d97fca73dc9a9fd26672Stepan Dyatkovskiy if (ArgRegsSaveSize) { 38633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Unlike T2 and ARM mode, the T1 pop instruction cannot restore 38733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // to LR, and we can't pop the value directly to the PC since 38833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // we need to update the SP after popping the value. Therefore, we 38933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // pop the old LR into R3 as a temporary. 39033464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 39136b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines // Get the last instruction, tBX_RET 39236b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines MBBI = MBB.getLastNonDebugInstr(); 39336b56886974eae4f9c5ebc96befd3e7bfe5de338Stephen Hines assert (MBBI->getOpcode() == ARM::tBX_RET); 39433464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // Epilogue for vararg functions: pop LR to R3 and branch off it. 39533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tPOP))) 39633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov .addReg(ARM::R3, RegState::Define); 39733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 398f65e4932f83ac0c36594d97fca73dc9a9fd26672Stepan Dyatkovskiy emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, ArgRegsSaveSize); 39933464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov 40079aa048d2102a7d4c8abbba82b4b8a41dbc32214Evan Cheng MachineInstrBuilder MIB = 40179aa048d2102a7d4c8abbba82b4b8a41dbc32214Evan Cheng BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX_RET_vararg)) 40279aa048d2102a7d4c8abbba82b4b8a41dbc32214Evan Cheng .addReg(ARM::R3, RegState::Kill); 40379aa048d2102a7d4c8abbba82b4b8a41dbc32214Evan Cheng AddDefaultPred(MIB); 404be06aacaa9a270384599bbfa850b967e9996b9fbJakob Stoklund Olesen MIB.copyImplicitOps(&*MBBI); 40533464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov // erase the old tBX_RET instruction 40633464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov MBB.erase(MBBI); 40733464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov } 40833464912237efaa0ed7060829e66b59055bdd48bAnton Korobeynikov} 409cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 41016c29b5f285f375be53dabaa73e3e91107485fe4Anton Korobeynikovbool Thumb1FrameLowering:: 411cd775ceff0b25a0b026f643a7990c2924bd310a3Anton KorobeynikovspillCalleeSavedRegisters(MachineBasicBlock &MBB, 412cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MachineBasicBlock::iterator MI, 413cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov const std::vector<CalleeSavedInfo> &CSI, 414cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov const TargetRegisterInfo *TRI) const { 415cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (CSI.empty()) 416cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov return false; 417cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 418cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov DebugLoc DL; 419cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MachineFunction &MF = *MBB.getParent(); 420cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo(); 421cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 422cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (MI != MBB.end()) DL = MI->getDebugLoc(); 423cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 424cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MachineInstrBuilder MIB = BuildMI(MBB, MI, DL, TII.get(ARM::tPUSH)); 425cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov AddDefaultPred(MIB); 426cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov for (unsigned i = CSI.size(); i != 0; --i) { 427cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov unsigned Reg = CSI[i-1].getReg(); 428cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov bool isKill = true; 429cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 430cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov // Add the callee-saved register as live-in unless it's LR and 431cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov // @llvm.returnaddress is called. If LR is returned for @llvm.returnaddress 432cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov // then it's already added to the function and entry block live-in sets. 433cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (Reg == ARM::LR) { 434cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MachineFunction &MF = *MBB.getParent(); 435cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (MF.getFrameInfo()->isReturnAddressTaken() && 436cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MF.getRegInfo().isLiveIn(Reg)) 437cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov isKill = false; 438cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov } 439cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 440cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (isKill) 441cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MBB.addLiveIn(Reg); 442cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 443cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MIB.addReg(Reg, getKillRegState(isKill)); 444cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov } 4453daccd82d3151fa3629de430b55698a81084fc9eAnton Korobeynikov MIB.setMIFlags(MachineInstr::FrameSetup); 446cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov return true; 447cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov} 448cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 44916c29b5f285f375be53dabaa73e3e91107485fe4Anton Korobeynikovbool Thumb1FrameLowering:: 450cd775ceff0b25a0b026f643a7990c2924bd310a3Anton KorobeynikovrestoreCalleeSavedRegisters(MachineBasicBlock &MBB, 451cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MachineBasicBlock::iterator MI, 452cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov const std::vector<CalleeSavedInfo> &CSI, 453cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov const TargetRegisterInfo *TRI) const { 454cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (CSI.empty()) 455cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov return false; 456cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 457cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MachineFunction &MF = *MBB.getParent(); 458cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>(); 459cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo(); 460cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 461f65e4932f83ac0c36594d97fca73dc9a9fd26672Stepan Dyatkovskiy bool isVarArg = AFI->getArgRegsSaveSize() > 0; 462cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov DebugLoc DL = MI->getDebugLoc(); 463cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MachineInstrBuilder MIB = BuildMI(MF, DL, TII.get(ARM::tPOP)); 464cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov AddDefaultPred(MIB); 465cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 466cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov bool NumRegs = false; 467cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov for (unsigned i = CSI.size(); i != 0; --i) { 468cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov unsigned Reg = CSI[i-1].getReg(); 469cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (Reg == ARM::LR) { 470cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov // Special epilogue for vararg functions. See emitEpilogue 471cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (isVarArg) 472cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov continue; 473cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov Reg = ARM::PC; 474cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov (*MIB).setDesc(TII.get(ARM::tPOP_RET)); 475be06aacaa9a270384599bbfa850b967e9996b9fbJakob Stoklund Olesen MIB.copyImplicitOps(&*MI); 476cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MI = MBB.erase(MI); 477cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov } 478cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MIB.addReg(Reg, getDefRegState(true)); 479cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov NumRegs = true; 480cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov } 481cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 482cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov // It's illegal to emit pop instruction without operands. 483cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov if (NumRegs) 484cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MBB.insert(MI, &*MIB); 485cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov else 486cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov MF.DeleteMachineInstr(MIB); 487cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov 488cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov return true; 489cd775ceff0b25a0b026f643a7990c2924bd310a3Anton Korobeynikov} 490