void XCoreFrameLowering::
processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
RegScavenger *RS) const {
XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
bool LRUsed = MF.getRegInfo().isPhysRegUsed(XCore::LR);
if (!LRUsed && !MF.getFunction()->isVarArg() &&
MF.getFrameInfo()->estimateStackSize(MF))
// If we need to extend the stack it is more efficient to use entsp / retsp.
// We force the LR to be saved so these instructions are used.
LRUsed = true;
if (MF.getMMI().callsUnwindInit() || MF.getMMI().callsEHReturn()) {
// The unwinder expects to find spill slots for the exception info regs R0
// & R1. These are used during llvm.eh.return() to 'restore' the exception
// info. N.B. we do not spill or restore R0, R1 during normal operation.
XFI->createEHSpillSlot(MF);
// As we will have a stack, we force the LR to be saved.
LRUsed = true;
}
if (LRUsed) {
// We will handle the LR in the prologue/epilogue
// and allocate space on the stack ourselves.
MF.getRegInfo().setPhysRegUnused(XCore::LR);
XFI->createLRSpillSlot(MF);
}
if (hasFP(MF))
// A callee save register is used to hold the FP.
// This needs saving / restoring in the epilogue / prologue.
XFI->createFPSpillSlot(MF);
}
void NyuziFrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
assert(&MF.front() == &MBB);
MachineFrameInfo *MFI = MF.getFrameInfo();
const NyuziInstrInfo &TII =
*static_cast<const NyuziInstrInfo *>(MF.getSubtarget().getInstrInfo());
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
// Compute stack size to allocate, keeping SP 64 byte aligned so we
// can do block vector load/stores
int StackSize = RoundUpToAlignment(MFI->getStackSize(), getStackAlignment());
// Bail if there is no stack allocation
if (StackSize == 0 && !MFI->adjustsStack())
return;
TII.adjustStackPointer(MBB, MBBI, -StackSize);
// Emit DW_CFA_def_cfa
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize));
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
// Find the instruction past the last instruction that saves a callee-saved
// register to the stack. We need to set up FP after its old value has been
// saved.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
for (unsigned i = 0; i < CSI.size(); ++i)
++MBBI;
// Iterate over list of callee-saved registers and emit .cfi_offset
// directives (debug information)
for (const auto &I : CSI) {
int64_t Offset = MFI->getObjectOffset(I.getFrameIdx());
unsigned Reg = I.getReg();
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
nullptr, MRI->getDwarfRegNum(Reg, 1), Offset));
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
}
// fp = sp
if (hasFP(MF)) {
BuildMI(MBB, MBBI, DL, TII.get(Nyuzi::MOVESS))
.addReg(Nyuzi::FP_REG)
.addReg(Nyuzi::SP_REG);
// emit ".cfi_def_cfa_register $fp" (debug information)
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
nullptr, MRI->getDwarfRegNum(Nyuzi::FP_REG, true)));
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
}
void MIRPrinter::print(const MachineFunction &MF) {
initRegisterMaskIds(MF);
yaml::MachineFunction YamlMF;
YamlMF.Name = MF.getName();
YamlMF.Alignment = MF.getAlignment();
YamlMF.ExposesReturnsTwice = MF.exposesReturnsTwice();
YamlMF.HasInlineAsm = MF.hasInlineAsm();
convert(YamlMF, MF.getRegInfo(), MF.getSubtarget().getRegisterInfo());
ModuleSlotTracker MST(MF.getFunction()->getParent());
MST.incorporateFunction(*MF.getFunction());
convert(MST, YamlMF.FrameInfo, *MF.getFrameInfo());
convertStackObjects(YamlMF, *MF.getFrameInfo(), MF.getMMI(), MST,
MF.getSubtarget().getRegisterInfo());
if (const auto *ConstantPool = MF.getConstantPool())
convert(YamlMF, *ConstantPool);
if (const auto *JumpTableInfo = MF.getJumpTableInfo())
convert(MST, YamlMF.JumpTableInfo, *JumpTableInfo);
raw_string_ostream StrOS(YamlMF.Body.Value.Value);
bool IsNewlineNeeded = false;
for (const auto &MBB : MF) {
if (IsNewlineNeeded)
StrOS << "\n";
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.print(MBB);
IsNewlineNeeded = true;
}
StrOS.flush();
yaml::Output Out(OS);
Out << YamlMF;
}
/// replaceFrameIndices - Replace all MO_FrameIndex operands with physical
/// register references and actual offsets.
///
void PEI::replaceFrameIndices(MachineFunction &Fn) {
const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering();
if (!TFI.needsFrameIndexResolution(Fn)) return;
MachineModuleInfo &MMI = Fn.getMMI();
const Function *F = Fn.getFunction();
const Function *ParentF = MMI.getWinEHParent(F);
unsigned FrameReg;
if (F == ParentF) {
WinEHFuncInfo &FuncInfo = MMI.getWinEHFuncInfo(Fn.getFunction());
// FIXME: This should be unconditional but we have bugs in the preparation
// pass.
if (FuncInfo.UnwindHelpFrameIdx != INT_MAX)
FuncInfo.UnwindHelpFrameOffset = TFI.getFrameIndexReferenceFromSP(
Fn, FuncInfo.UnwindHelpFrameIdx, FrameReg);
for (WinEHTryBlockMapEntry &TBME : FuncInfo.TryBlockMap) {
for (WinEHHandlerType &H : TBME.HandlerArray) {
unsigned UnusedReg;
if (H.CatchObj.FrameIndex == INT_MAX)
H.CatchObj.FrameOffset = INT_MAX;
else
H.CatchObj.FrameOffset =
TFI.getFrameIndexReference(Fn, H.CatchObj.FrameIndex, UnusedReg);
}
}
}
// Store SPAdj at exit of a basic block.
SmallVector<int, 8> SPState;
SPState.resize(Fn.getNumBlockIDs());
SmallPtrSet<MachineBasicBlock*, 8> Reachable;
// Iterate over the reachable blocks in DFS order.
for (auto DFI = df_ext_begin(&Fn, Reachable), DFE = df_ext_end(&Fn, Reachable);
DFI != DFE; ++DFI) {
int SPAdj = 0;
// Check the exit state of the DFS stack predecessor.
if (DFI.getPathLength() >= 2) {
MachineBasicBlock *StackPred = DFI.getPath(DFI.getPathLength() - 2);
assert(Reachable.count(StackPred) &&
"DFS stack predecessor is already visited.\n");
SPAdj = SPState[StackPred->getNumber()];
}
MachineBasicBlock *BB = *DFI;
replaceFrameIndices(BB, Fn, SPAdj);
SPState[BB->getNumber()] = SPAdj;
}
// Handle the unreachable blocks.
for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
if (Reachable.count(BB))
// Already handled in DFS traversal.
continue;
int SPAdj = 0;
replaceFrameIndices(BB, Fn, SPAdj);
}
}
bool AArch64FrameLowering::assignCalleeSavedSpillSlots(
MachineFunction &MF, const TargetRegisterInfo *TRI,
std::vector<CalleeSavedInfo> &CSI,
unsigned &MinCSFrameIndex, unsigned &MaxCSFrameIndex) const {
const AArch64RegisterInfo *RegInfo = static_cast<const AArch64RegisterInfo *>(
MF.getSubtarget().getRegisterInfo());
if (!MF.getFunction()->getAttributes().hasAttrSomewhere(
Attribute::SwiftError))
return false;
if (CSI.empty())
return true; // Early exit if no callee saved registers are modified!
MachineFrameInfo *MFI = MF.getFrameInfo();
// Simplify the logic here since AArch64 does not have fixed or reserved
// spill slots.
// Now that we know which registers need to be saved and restored, allocate
// stack slots according to getCalleeSavedRegsForLayout.
const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegsForLayout(&MF);
for (unsigned i = 0; CSRegs[i]; ++i) {
unsigned Reg = CSRegs[i];
// Assign a slot for functions which call __builtin_unwind_init.
if (!MF.getRegInfo().isPhysRegUsed(Reg) && !MF.getMMI().callsUnwindInit())
continue;
DEBUG(dbgs() << "try to allocate stack slot for reg " << Reg << '\n');
const TargetRegisterClass *RC = RegInfo->getMinimalPhysRegClass(Reg);
// Just spill it anywhere convenient.
unsigned Align = RC->getAlignment();
unsigned StackAlign = getStackAlignment();
// We may not be able to satisfy the desired alignment specification of
// the TargetRegisterClass if the stack alignment is smaller. Use the
// min.
Align = std::min(Align, StackAlign);
int FrameIdx = MFI->CreateStackObject(RC->getSize(), Align, true);
if ((unsigned)FrameIdx < MinCSFrameIndex) MinCSFrameIndex = FrameIdx;
if ((unsigned)FrameIdx > MaxCSFrameIndex) MaxCSFrameIndex = FrameIdx;
// Find the corresponding entry in CSI for Reg.
for (std::vector<CalleeSavedInfo>::iterator I = CSI.begin(), E = CSI.end();
I != E; ++I)
if (I->getReg() == Reg) {
I->setFrameIdx(FrameIdx);
break;
}
}
return true;
}
/// hasFP - Return true if the specified function should have a dedicated frame
/// pointer register. This is true if the function has variable sized allocas
/// or if frame pointer elimination is disabled.
bool X86FrameInfo::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const MachineModuleInfo &MMI = MF.getMMI();
const TargetRegisterInfo *RI = TM.getRegisterInfo();
return (DisableFramePointerElim(MF) ||
RI->needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
MFI->isFrameAddressTaken() ||
MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
MMI.callsUnwindInit());
}
void Mips16FrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
MachineFrameInfo *MFI = MF.getFrameInfo();
const Mips16InstrInfo &TII =
*static_cast<const Mips16InstrInfo *>(STI.getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
// Debug location must be unknown since the first debug location is used
// to determine the end of the prologue.
DebugLoc dl;
uint64_t StackSize = MFI->getStackSize();
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
MachineLocation DstML, SrcML;
// Adjust stack.
TII.makeFrame(Mips::SP, StackSize, MBB, MBBI);
// emit ".cfi_def_cfa_offset StackSize"
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
unsigned Reg = I->getReg();
unsigned DReg = MRI->getDwarfRegNum(Reg, true);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, DReg, Offset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
}
if (hasFP(MF))
BuildMI(MBB, MBBI, dl, TII.get(Mips::MoveR3216), Mips::S0)
.addReg(Mips::SP).setMIFlag(MachineInstr::FrameSetup);
}
void Mips16FrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
const Mips16InstrInfo &TII =
*static_cast<const Mips16InstrInfo*>(MF.getTarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
uint64_t StackSize = MFI->getStackSize();
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
MachineLocation DstML, SrcML;
// Adjust stack.
TII.makeFrame(Mips::SP, StackSize, MBB, MBBI);
// emit ".cfi_def_cfa_offset StackSize"
MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(AdjustSPLabel, -StackSize));
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
unsigned Reg = I->getReg();
unsigned DReg = MRI->getDwarfRegNum(Reg, true);
MMI.addFrameInst(MCCFIInstruction::createOffset(CSLabel, DReg, Offset));
}
}
if (hasFP(MF))
BuildMI(MBB, MBBI, dl, TII.get(Mips::MoveR3216), Mips::S0)
.addReg(Mips::SP);
}
// This checks whether the transformation is legal.
// Also returns false in cases where it's potentially legal, but
// we don't even want to try.
bool X86CallFrameOptimization::isLegal(MachineFunction &MF) {
if (NoX86CFOpt.getValue())
return false;
// We currently only support call sequences where *all* parameters.
// are passed on the stack.
// No point in running this in 64-bit mode, since some arguments are
// passed in-register in all common calling conventions, so the pattern
// we're looking for will never match.
if (STI->is64Bit())
return false;
// We can't encode multiple DW_CFA_GNU_args_size or DW_CFA_def_cfa_offset
// in the compact unwind encoding that Darwin uses. So, bail if there
// is a danger of that being generated.
if (STI->isTargetDarwin() &&
(!MF.getMMI().getLandingPads().empty() ||
(MF.getFunction()->needsUnwindTableEntry() && !TFL->hasFP(MF))))
return false;
// You would expect straight-line code between call-frame setup and
// call-frame destroy. You would be wrong. There are circumstances (e.g.
// CMOV_GR8 expansion of a select that feeds a function call!) where we can
// end up with the setup and the destroy in different basic blocks.
// This is bad, and breaks SP adjustment.
// So, check that all of the frames in the function are closed inside
// the same block, and, for good measure, that there are no nested frames.
unsigned FrameSetupOpcode = TII->getCallFrameSetupOpcode();
unsigned FrameDestroyOpcode = TII->getCallFrameDestroyOpcode();
for (MachineBasicBlock &BB : MF) {
bool InsideFrameSequence = false;
for (MachineInstr &MI : BB) {
if (MI.getOpcode() == FrameSetupOpcode) {
if (InsideFrameSequence)
return false;
InsideFrameSequence = true;
} else if (MI.getOpcode() == FrameDestroyOpcode) {
if (!InsideFrameSequence)
return false;
InsideFrameSequence = false;
}
}
if (InsideFrameSequence)
return false;
}
return true;
}
/// insertPrologEpilogCode - Scan the function for modified callee saved
/// registers, insert spill code for these callee saved registers, then add
/// prolog and epilog code to the function.
void PEI::insertPrologEpilogCode(MachineFunction &MF) {
const TargetFrameLowering &TFI = *MF.getSubtarget().getFrameLowering();
// Add prologue to the function...
for (MachineBasicBlock *SaveBlock : SaveBlocks)
TFI.emitPrologue(MF, *SaveBlock);
// Add epilogue to restore the callee-save registers in each exiting block.
for (MachineBasicBlock *RestoreBlock : RestoreBlocks)
TFI.emitEpilogue(MF, *RestoreBlock);
for (MachineBasicBlock *SaveBlock : SaveBlocks)
TFI.inlineStackProbe(MF, *SaveBlock);
// Emit additional code that is required to support segmented stacks, if
// we've been asked for it. This, when linked with a runtime with support
// for segmented stacks (libgcc is one), will result in allocating stack
// space in small chunks instead of one large contiguous block.
if (MF.shouldSplitStack()) {
for (MachineBasicBlock *SaveBlock : SaveBlocks)
TFI.adjustForSegmentedStacks(MF, *SaveBlock);
// Record that there are split-stack functions, so we will emit a
// special section to tell the linker.
MF.getMMI().setHasSplitStack(true);
} else
MF.getMMI().setHasNosplitStack(true);
// Emit additional code that is required to explicitly handle the stack in
// HiPE native code (if needed) when loaded in the Erlang/OTP runtime. The
// approach is rather similar to that of Segmented Stacks, but it uses a
// different conditional check and another BIF for allocating more stack
// space.
if (MF.getFunction().getCallingConv() == CallingConv::HiPE)
for (MachineBasicBlock *SaveBlock : SaveBlocks)
TFI.adjustForHiPEPrologue(MF, *SaveBlock);
}
bool ImplicitNullChecks::runOnMachineFunction(MachineFunction &MF) {
TII = MF.getSubtarget().getInstrInfo();
TRI = MF.getRegInfo().getTargetRegisterInfo();
MMI = &MF.getMMI();
SmallVector<NullCheck, 16> NullCheckList;
for (auto &MBB : MF)
analyzeBlockForNullChecks(MBB, NullCheckList);
if (!NullCheckList.empty())
rewriteNullChecks(NullCheckList);
return !NullCheckList.empty();
}
void SparcFrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
MachineFrameInfo *MFI = MF.getFrameInfo();
const SparcInstrInfo &TII =
*static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
// Get the number of bytes to allocate from the FrameInfo
int NumBytes = (int) MFI->getStackSize();
unsigned SAVEri = SP::SAVEri;
unsigned SAVErr = SP::SAVErr;
if (FuncInfo->isLeafProc()) {
if (NumBytes == 0)
return;
SAVEri = SP::ADDri;
SAVErr = SP::ADDrr;
}
NumBytes = -MF.getSubtarget<SparcSubtarget>().getAdjustedFrameSize(NumBytes);
emitSPAdjustment(MF, MBB, MBBI, NumBytes, SAVErr, SAVEri);
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
unsigned regFP = MRI->getDwarfRegNum(SP::I6, true);
// Emit ".cfi_def_cfa_register 30".
unsigned CFIIndex =
MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(nullptr, regFP));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
// Emit ".cfi_window_save".
CFIIndex = MMI.addFrameInst(MCCFIInstruction::createWindowSave(nullptr));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
unsigned regInRA = MRI->getDwarfRegNum(SP::I7, true);
unsigned regOutRA = MRI->getDwarfRegNum(SP::O7, true);
// Emit ".cfi_register 15, 31".
CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createRegister(nullptr, regOutRA, regInRA));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
void Mips16FrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
const Mips16InstrInfo &TII =
*static_cast<const Mips16InstrInfo*>(MF.getTarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
uint64_t StackSize = MFI->getStackSize();
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
MachineLocation DstML, SrcML;
// Adjust stack.
TII.makeFrame(Mips::SP, StackSize, MBB, MBBI);
// emit ".cfi_def_cfa_offset StackSize"
MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
DstML = MachineLocation(MachineLocation::VirtualFP);
SrcML = MachineLocation(MachineLocation::VirtualFP, -StackSize);
MMI.addFrameMove(AdjustSPLabel, DstML, SrcML);
MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);
DstML = MachineLocation(MachineLocation::VirtualFP, -8);
SrcML = MachineLocation(Mips::S1);
MMI.addFrameMove(CSLabel, DstML, SrcML);
DstML = MachineLocation(MachineLocation::VirtualFP, -12);
SrcML = MachineLocation(Mips::S0);
MMI.addFrameMove(CSLabel, DstML, SrcML);
DstML = MachineLocation(MachineLocation::VirtualFP, -4);
SrcML = MachineLocation(Mips::RA);
MMI.addFrameMove(CSLabel, DstML, SrcML);
if (hasFP(MF))
BuildMI(MBB, MBBI, dl, TII.get(Mips::MoveR3216), Mips::S0)
.addReg(Mips::SP);
}
// This checks whether the transformation is legal.
// Also returns false in cases where it's potentially legal, but
// we don't even want to try.
bool X86CallFrameOptimization::isLegal(MachineFunction &MF) {
if (NoX86CFOpt.getValue())
return false;
// We can't encode multiple DW_CFA_GNU_args_size or DW_CFA_def_cfa_offset
// in the compact unwind encoding that Darwin uses. So, bail if there
// is a danger of that being generated.
if (STI->isTargetDarwin() &&
(!MF.getMMI().getLandingPads().empty() ||
(MF.getFunction()->needsUnwindTableEntry() && !TFL->hasFP(MF))))
return false;
// It is not valid to change the stack pointer outside the prolog/epilog
// on 64-bit Windows.
if (STI->isTargetWin64())
return false;
// You would expect straight-line code between call-frame setup and
// call-frame destroy. You would be wrong. There are circumstances (e.g.
// CMOV_GR8 expansion of a select that feeds a function call!) where we can
// end up with the setup and the destroy in different basic blocks.
// This is bad, and breaks SP adjustment.
// So, check that all of the frames in the function are closed inside
// the same block, and, for good measure, that there are no nested frames.
unsigned FrameSetupOpcode = TII->getCallFrameSetupOpcode();
unsigned FrameDestroyOpcode = TII->getCallFrameDestroyOpcode();
for (MachineBasicBlock &BB : MF) {
bool InsideFrameSequence = false;
for (MachineInstr &MI : BB) {
if (MI.getOpcode() == FrameSetupOpcode) {
if (InsideFrameSequence)
return false;
InsideFrameSequence = true;
} else if (MI.getOpcode() == FrameDestroyOpcode) {
if (!InsideFrameSequence)
return false;
InsideFrameSequence = false;
}
}
if (InsideFrameSequence)
return false;
}
return true;
}
void SparcFrameLowering::emitPrologue(MachineFunction &MF) const {
SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
const SparcInstrInfo &TII =
*static_cast<const SparcInstrInfo*>(MF.getTarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
// Get the number of bytes to allocate from the FrameInfo
int NumBytes = (int) MFI->getStackSize();
unsigned SAVEri = SP::SAVEri;
unsigned SAVErr = SP::SAVErr;
if (FuncInfo->isLeafProc()) {
if (NumBytes == 0)
return;
SAVEri = SP::ADDri;
SAVErr = SP::ADDrr;
}
NumBytes = - SubTarget.getAdjustedFrameSize(NumBytes);
emitSPAdjustment(MF, MBB, MBBI, NumBytes, SAVErr, SAVEri);
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl, TII.get(SP::PROLOG_LABEL)).addSym(FrameLabel);
unsigned regFP = MRI->getDwarfRegNum(SP::I6, true);
// Emit ".cfi_def_cfa_register 30".
MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(FrameLabel,
regFP));
// Emit ".cfi_window_save".
MMI.addFrameInst(MCCFIInstruction::createWindowSave(FrameLabel));
unsigned regInRA = MRI->getDwarfRegNum(SP::I7, true);
unsigned regOutRA = MRI->getDwarfRegNum(SP::O7, true);
// Emit ".cfi_register 15, 31".
MMI.addFrameInst(MCCFIInstruction::createRegister(FrameLabel,
regOutRA,
regInRA));
}
bool MIRParserImpl::parseStackObjectsDebugInfo(
MachineFunction &MF, PerFunctionMIParsingState &PFS,
const yaml::MachineStackObject &Object, int FrameIdx) {
// Debug information can only be attached to stack objects; Fixed stack
// objects aren't supported.
assert(FrameIdx >= 0 && "Expected a stack object frame index");
MDNode *Var = nullptr, *Expr = nullptr, *Loc = nullptr;
if (parseMDNode(Var, Object.DebugVar, MF, PFS) ||
parseMDNode(Expr, Object.DebugExpr, MF, PFS) ||
parseMDNode(Loc, Object.DebugLoc, MF, PFS))
return true;
if (!Var && !Expr && !Loc)
return false;
DILocalVariable *DIVar = nullptr;
DIExpression *DIExpr = nullptr;
DILocation *DILoc = nullptr;
if (typecheckMDNode(DIVar, Var, Object.DebugVar, "DILocalVariable", *this) ||
typecheckMDNode(DIExpr, Expr, Object.DebugExpr, "DIExpression", *this) ||
typecheckMDNode(DILoc, Loc, Object.DebugLoc, "DILocation", *this))
return true;
MF.getMMI().setVariableDbgInfo(DIVar, DIExpr, unsigned(FrameIdx), DILoc);
return false;
}
bool SIDebuggerInsertNops::runOnMachineFunction(MachineFunction &MF) {
// Skip this pass if "amdgpu-debugger-insert-nops" attribute was not
// specified.
const AMDGPUSubtarget &ST = MF.getSubtarget<AMDGPUSubtarget>();
if (!ST.debuggerInsertNops())
return false;
// Skip machine functions without debug info.
if (!MF.getMMI().hasDebugInfo())
return false;
// Target instruction info.
const SIInstrInfo *TII =
static_cast<const SIInstrInfo*>(MF.getSubtarget().getInstrInfo());
// Set containing line numbers that have nop inserted.
DenseSet<unsigned> NopInserted;
for (auto &MBB : MF) {
for (auto MI = MBB.begin(); MI != MBB.end(); ++MI) {
// Skip DBG_VALUE instructions and instructions without location.
if (MI->isDebugValue() || !MI->getDebugLoc())
continue;
// Insert nop instruction if line number does not have nop inserted.
auto DL = MI->getDebugLoc();
if (NopInserted.find(DL.getLine()) == NopInserted.end()) {
BuildMI(MBB, *MI, DL, TII->get(AMDGPU::S_NOP))
.addImm(0);
NopInserted.insert(DL.getLine());
}
}
}
return true;
}
bool XCoreRegisterInfo::needsFrameMoves(const MachineFunction &MF) {
return MF.getMMI().hasDebugInfo() ||
MF.getFunction()->needsUnwindTableEntry();
}
void SPURegisterInfo::emitPrologue(MachineFunction &MF) const
{
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo &MMI = MF.getMMI();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
// Prepare for debug frame info.
bool hasDebugInfo = MMI.hasDebugInfo();
MCSymbol *FrameLabel = 0;
// Move MBBI back to the beginning of the function.
MBBI = MBB.begin();
// Work out frame sizes.
determineFrameLayout(MF);
int FrameSize = MFI->getStackSize();
assert((FrameSize & 0xf) == 0
&& "SPURegisterInfo::emitPrologue: FrameSize not aligned");
// the "empty" frame size is 16 - just the register scavenger spill slot
if (FrameSize > 16 || MFI->adjustsStack()) {
FrameSize = -(FrameSize + SPUFrameInfo::minStackSize());
if (hasDebugInfo) {
// Mark effective beginning of when frame pointer becomes valid.
FrameLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl, TII.get(SPU::DBG_LABEL)).addSym(FrameLabel);
}
// Adjust stack pointer, spilling $lr -> 16($sp) and $sp -> -FrameSize($sp)
// for the ABI
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R0).addImm(16)
.addReg(SPU::R1);
if (isInt<10>(FrameSize)) {
// Spill $sp to adjusted $sp
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R1).addImm(FrameSize)
.addReg(SPU::R1);
// Adjust $sp by required amout
BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1).addReg(SPU::R1)
.addImm(FrameSize);
} else if (isInt<16>(FrameSize)) {
// Frame size can be loaded into ILr32n, so temporarily spill $r2 and use
// $r2 to adjust $sp:
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2)
.addImm(-16)
.addReg(SPU::R1);
BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2)
.addImm(FrameSize);
BuildMI(MBB, MBBI, dl, TII.get(SPU::STQXr32), SPU::R1)
.addReg(SPU::R2)
.addReg(SPU::R1);
BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1)
.addReg(SPU::R1)
.addReg(SPU::R2);
BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2)
.addReg(SPU::R2)
.addImm(16);
BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2)
.addReg(SPU::R2)
.addReg(SPU::R1);
} else {
report_fatal_error("Unhandled frame size: " + Twine(FrameSize));
}
if (hasDebugInfo) {
std::vector<MachineMove> &Moves = MMI.getFrameMoves();
// Show update of SP.
MachineLocation SPDst(MachineLocation::VirtualFP);
MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize);
Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
// Add callee saved registers to move list.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
unsigned Reg = CSI[I].getReg();
if (Reg == SPU::R0) continue;
MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
MachineLocation CSSrc(Reg);
Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
}
// Mark effective beginning of when frame pointer is ready.
MCSymbol *ReadyLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl, TII.get(SPU::DBG_LABEL)).addSym(ReadyLabel);
MachineLocation FPDst(SPU::R1);
MachineLocation FPSrc(MachineLocation::VirtualFP);
Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc));
}
} else {
// This is a leaf function -- insert a branch hint iff there are
// sufficient number instructions in the basic block. Note that
// this is just a best guess based on the basic block's size.
if (MBB.size() >= (unsigned) SPUFrameInfo::branchHintPenalty()) {
MachineBasicBlock::iterator MBBI = prior(MBB.end());
dl = MBBI->getDebugLoc();
// Insert terminator label
BuildMI(MBB, MBBI, dl, TII.get(SPU::DBG_LABEL))
.addSym(MMI.getContext().CreateTempSymbol());
}
}
}
void Cpu0FrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
Cpu0FunctionInfo *Cpu0FI = MF.getInfo<Cpu0FunctionInfo>();
const Cpu0InstrInfo &TII =
*static_cast<const Cpu0InstrInfo*>(MF.getTarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
unsigned SP = Cpu0::SP;
// lbd document - mark - Cpu0::SP
unsigned FP = Cpu0::FP;
unsigned ZERO = Cpu0::ZERO;
unsigned ADDu = Cpu0::ADDu;
// lbd document - mark - Cpu0::ADDu
unsigned ADDiu = Cpu0::ADDiu;
// First, compute final stack size.
unsigned StackAlign = getStackAlignment();
unsigned RegSize = 4;
unsigned LocalVarAreaOffset =
Cpu0FI->needGPSaveRestore() ?
(MFI->getObjectOffset(Cpu0FI->getGPFI()) + RegSize) :
Cpu0FI->getMaxCallFrameSize();
uint64_t StackSize = RoundUpToAlignment(LocalVarAreaOffset, StackAlign) +
RoundUpToAlignment(MFI->getStackSize(), StackAlign);
// Update stack size
MFI->setStackSize(StackSize);
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
MachineLocation DstML, SrcML;
// Adjust stack.
if (isInt<16>(-StackSize)) // addiu sp, sp, (-stacksize)
BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(-StackSize);
else { // Expand immediate that doesn't fit in 16-bit.
Cpu0FI->setEmitNOAT();
expandLargeImm(SP, -StackSize, TII, MBB, MBBI, dl);
}
// emit ".cfi_def_cfa_offset StackSize"
MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(AdjustSPLabel, -StackSize));
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
// Find the instruction past the last instruction that saves a callee-saved
// register to the stack.
for (unsigned i = 0; i < CSI.size(); ++i)
++MBBI;
// Iterate over list of callee-saved registers and emit .cfi_offset
// directives.
MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
unsigned Reg = I->getReg();
{
// Reg is in CPURegs.
MMI.addFrameInst(MCCFIInstruction::createOffset(
CSLabel, MRI->getDwarfRegNum(Reg, 1), Offset));
}
}
}
// if framepointer enabled, set it to point to the stack pointer.
if (hasFP(MF)) {
// Insert instruction "move $fp, $sp" at this location.
BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO);
// emit ".cfi_def_cfa_register $fp"
MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel);
MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
SetFPLabel, MRI->getDwarfRegNum(FP, true)));
}
// Restore GP from the saved stack location
if (Cpu0FI->needGPSaveRestore()) {
unsigned Offset = MFI->getObjectOffset(Cpu0FI->getGPFI());
BuildMI(MBB, MBBI, dl, TII.get(Cpu0::CPRESTORE)).addImm(Offset)
.addReg(Cpu0::GP);
} // lbd document - mark - if (Cpu0FI->needGPSaveRestore())
}
void AArch64FrameLowering::emitPrologue(MachineFunction &MF) const {
AArch64MachineFunctionInfo *FuncInfo =
MF.getInfo<AArch64MachineFunctionInfo>();
MachineBasicBlock &MBB = MF.front();
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
DebugLoc DL = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
bool NeedsFrameMoves = MMI.hasDebugInfo()
|| MF.getFunction()->needsUnwindTableEntry();
uint64_t NumInitialBytes, NumResidualBytes;
// Currently we expect the stack to be laid out by
// sub sp, sp, #initial
// stp x29, x30, [sp, #offset]
// ...
// str xxx, [sp, #offset]
// sub sp, sp, #rest (possibly via extra instructions).
if (MFI->getCalleeSavedInfo().size()) {
// If there are callee-saved registers, we want to store them efficiently as
// a block, and virtual base assignment happens too early to do it for us so
// we adjust the stack in two phases: first just for callee-saved fiddling,
// then to allocate the rest of the frame.
splitSPAdjustments(MFI->getStackSize(), NumInitialBytes, NumResidualBytes);
} else {
// If there aren't any callee-saved registers, two-phase adjustment is
// inefficient. It's more efficient to adjust with NumInitialBytes too
// because when we're in a "callee pops argument space" situation, that pop
// must be tacked onto Initial for correctness.
NumInitialBytes = MFI->getStackSize();
NumResidualBytes = 0;
}
// Tell everyone else how much adjustment we're expecting them to use. In
// particular if an adjustment is required for a tail call the epilogue could
// have a different view of things.
FuncInfo->setInitialStackAdjust(NumInitialBytes);
emitSPUpdate(MBB, MBBI, DL, TII, AArch64::X16, -NumInitialBytes,
MachineInstr::FrameSetup);
if (NeedsFrameMoves && NumInitialBytes) {
// We emit this update even if the CFA is set from a frame pointer later so
// that the CFA is valid in the interim.
MachineLocation Dst(MachineLocation::VirtualFP);
unsigned Reg = MRI->getDwarfRegNum(AArch64::XSP, true);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfa(nullptr, Reg, -NumInitialBytes));
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
// Otherwise we need to set the frame pointer and/or add a second stack
// adjustment.
bool FPNeedsSetting = hasFP(MF);
for (; MBBI != MBB.end(); ++MBBI) {
// Note that this search makes strong assumptions about the operation used
// to store the frame-pointer: it must be "STP x29, x30, ...". This could
// change in future, but until then there's no point in implementing
// untestable more generic cases.
if (FPNeedsSetting && MBBI->getOpcode() == AArch64::LSPair64_STR
&& MBBI->getOperand(0).getReg() == AArch64::X29) {
int64_t X29FrameIdx = MBBI->getOperand(2).getIndex();
FuncInfo->setFramePointerOffset(MFI->getObjectOffset(X29FrameIdx));
++MBBI;
emitRegUpdate(MBB, MBBI, DL, TII, AArch64::X29, AArch64::XSP,
AArch64::X29,
NumInitialBytes + MFI->getObjectOffset(X29FrameIdx),
MachineInstr::FrameSetup);
// The offset adjustment used when emitting debugging locations relative
// to whatever frame base is set. AArch64 uses the default frame base (FP
// or SP) and this adjusts the calculations to be correct.
MFI->setOffsetAdjustment(- MFI->getObjectOffset(X29FrameIdx)
- MFI->getStackSize());
if (NeedsFrameMoves) {
unsigned Reg = MRI->getDwarfRegNum(AArch64::X29, true);
unsigned Offset = MFI->getObjectOffset(X29FrameIdx);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfa(nullptr, Reg, Offset));
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
FPNeedsSetting = false;
}
if (!MBBI->getFlag(MachineInstr::FrameSetup))
break;
}
assert(!FPNeedsSetting && "Frame pointer couldn't be set");
emitSPUpdate(MBB, MBBI, DL, TII, AArch64::X16, -NumResidualBytes,
MachineInstr::FrameSetup);
// Now we emit the rest of the frame setup information, if necessary: we've
// already noted the FP and initial SP moves so we're left with the prologue's
// final SP update and callee-saved register locations.
if (!NeedsFrameMoves)
return;
// The rest of the stack adjustment
if (!hasFP(MF) && NumResidualBytes) {
MachineLocation Dst(MachineLocation::VirtualFP);
unsigned Reg = MRI->getDwarfRegNum(AArch64::XSP, true);
unsigned Offset = NumResidualBytes + NumInitialBytes;
unsigned CFIIndex =
MMI.addFrameInst(MCCFIInstruction::createDefCfa(nullptr, Reg, -Offset));
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
// And any callee-saved registers (it's fine to leave them to the end here,
// because the old values are still valid at this point.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
unsigned Offset = MFI->getObjectOffset(I->getFrameIdx());
unsigned Reg = MRI->getDwarfRegNum(I->getReg(), true);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg, Offset));
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
}
}
void HexagonFrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo &MMI = MF.getMMI();
MachineBasicBlock::iterator MBBI = MBB.begin();
const HexagonRegisterInfo *QRI =
static_cast<const HexagonRegisterInfo *>(MF.getTarget().getRegisterInfo());
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
determineFrameLayout(MF);
// Check if frame moves are needed for EH.
bool needsFrameMoves = MMI.hasDebugInfo() ||
!MF.getFunction()->needsUnwindTableEntry();
// Get the number of bytes to allocate from the FrameInfo.
int NumBytes = (int) MFI->getStackSize();
// LLVM expects allocframe not to be the first instruction in the
// basic block.
MachineBasicBlock::iterator InsertPt = MBB.begin();
//
// ALLOCA adjust regs. Iterate over ADJDYNALLOC nodes and change the offset.
//
HexagonMachineFunctionInfo *FuncInfo =
MF.getInfo<HexagonMachineFunctionInfo>();
const std::vector<MachineInstr*>& AdjustRegs =
FuncInfo->getAllocaAdjustInsts();
for (std::vector<MachineInstr*>::const_iterator i = AdjustRegs.begin(),
e = AdjustRegs.end();
i != e; ++i) {
MachineInstr* MI = *i;
assert((MI->getOpcode() == Hexagon::ADJDYNALLOC) &&
"Expected adjust alloca node");
MachineOperand& MO = MI->getOperand(2);
assert(MO.isImm() && "Expected immediate");
MO.setImm(MFI->getMaxCallFrameSize());
}
std::vector<MachineMove> &Moves = MMI.getFrameMoves();
if (needsFrameMoves) {
// Advance CFA. DW_CFA_def_cfa
unsigned FPReg = QRI->getFrameRegister();
unsigned RAReg = QRI->getRARegister();
MachineLocation Dst(MachineLocation::VirtualFP);
MachineLocation Src(FPReg, -8);
Moves.push_back(MachineMove(0, Dst, Src));
// R31 = (R31 - #4)
MachineLocation LRDst(RAReg, -4);
MachineLocation LRSrc(RAReg);
Moves.push_back(MachineMove(0, LRDst, LRSrc));
// R30 = (R30 - #8)
MachineLocation SPDst(FPReg, -8);
MachineLocation SPSrc(FPReg);
Moves.push_back(MachineMove(0, SPDst, SPSrc));
}
//
// Only insert ALLOCFRAME if we need to.
//
if (hasFP(MF)) {
// Check for overflow.
// Hexagon_TODO: Ugh! hardcoding. Is there an API that can be used?
const int ALLOCFRAME_MAX = 16384;
const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
if (NumBytes >= ALLOCFRAME_MAX) {
// Emit allocframe(#0).
BuildMI(MBB, InsertPt, dl, TII.get(Hexagon::ALLOCFRAME)).addImm(0);
// Subtract offset from frame pointer.
BuildMI(MBB, InsertPt, dl, TII.get(Hexagon::CONST32_Int_Real),
HEXAGON_RESERVED_REG_1).addImm(NumBytes);
BuildMI(MBB, InsertPt, dl, TII.get(Hexagon::SUB_rr),
QRI->getStackRegister()).
addReg(QRI->getStackRegister()).
addReg(HEXAGON_RESERVED_REG_1);
} else {
BuildMI(MBB, InsertPt, dl, TII.get(Hexagon::ALLOCFRAME)).addImm(NumBytes);
}
}
}
void MipsFrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
const MipsRegisterInfo *RegInfo =
static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
const MipsInstrInfo &TII =
*static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
bool isPIC = (MF.getTarget().getRelocationModel() == Reloc::PIC_);
unsigned SP = STI.isABI_N64() ? Mips::SP_64 : Mips::SP;
unsigned FP = STI.isABI_N64() ? Mips::FP_64 : Mips::FP;
unsigned ZERO = STI.isABI_N64() ? Mips::ZERO_64 : Mips::ZERO;
unsigned ADDu = STI.isABI_N64() ? Mips::DADDu : Mips::ADDu;
unsigned ADDiu = STI.isABI_N64() ? Mips::DADDiu : Mips::ADDiu;
// First, compute final stack size.
unsigned RegSize = STI.isGP32bit() ? 4 : 8;
unsigned StackAlign = getStackAlignment();
unsigned LocalVarAreaOffset = MipsFI->needGPSaveRestore() ?
(MFI->getObjectOffset(MipsFI->getGPFI()) + RegSize) :
MipsFI->getMaxCallFrameSize();
uint64_t StackSize = RoundUpToAlignment(LocalVarAreaOffset, StackAlign) +
RoundUpToAlignment(MFI->getStackSize(), StackAlign);
// Update stack size
MFI->setStackSize(StackSize);
// Emit instructions that set the global base register if the target ABI is
// O32.
if (isPIC && MipsFI->globalBaseRegSet() && STI.isABI_O32() &&
!MipsFI->globalBaseRegFixed()) {
// See MipsInstrInfo.td for explanation.
MachineBasicBlock *NewEntry = MF.CreateMachineBasicBlock();
MF.insert(&MBB, NewEntry);
NewEntry->addSuccessor(&MBB);
// Copy live in registers.
for (MachineBasicBlock::livein_iterator R = MBB.livein_begin();
R != MBB.livein_end(); ++R)
NewEntry->addLiveIn(*R);
BuildMI(*NewEntry, NewEntry->begin(), dl, TII.get(Mips:: SETGP01),
Mips::V0);
}
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
std::vector<MachineMove> &Moves = MMI.getFrameMoves();
MachineLocation DstML, SrcML;
// Adjust stack.
if (isInt<16>(-StackSize)) // addi sp, sp, (-stacksize)
BuildMI(MBB, MBBI, dl, TII.get(ADDiu), SP).addReg(SP).addImm(-StackSize);
else { // Expand immediate that doesn't fit in 16-bit.
MipsFI->setEmitNOAT();
expandLargeImm(SP, -StackSize, STI.isABI_N64(), TII, MBB, MBBI, dl);
}
// emit ".cfi_def_cfa_offset StackSize"
MCSymbol *AdjustSPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(AdjustSPLabel);
DstML = MachineLocation(MachineLocation::VirtualFP);
SrcML = MachineLocation(MachineLocation::VirtualFP, -StackSize);
Moves.push_back(MachineMove(AdjustSPLabel, DstML, SrcML));
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
// Find the instruction past the last instruction that saves a callee-saved
// register to the stack.
for (unsigned i = 0; i < CSI.size(); ++i)
++MBBI;
// Iterate over list of callee-saved registers and emit .cfi_offset
// directives.
MCSymbol *CSLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(CSLabel);
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
unsigned Reg = I->getReg();
// If Reg is a double precision register, emit two cfa_offsets,
// one for each of the paired single precision registers.
if (Mips::AFGR64RegisterClass->contains(Reg)) {
const uint16_t *SubRegs = RegInfo->getSubRegisters(Reg);
MachineLocation DstML0(MachineLocation::VirtualFP, Offset);
MachineLocation DstML1(MachineLocation::VirtualFP, Offset + 4);
MachineLocation SrcML0(*SubRegs);
MachineLocation SrcML1(*(SubRegs + 1));
if (!STI.isLittle())
std::swap(SrcML0, SrcML1);
Moves.push_back(MachineMove(CSLabel, DstML0, SrcML0));
Moves.push_back(MachineMove(CSLabel, DstML1, SrcML1));
}
else {
// Reg is either in CPURegs or FGR32.
DstML = MachineLocation(MachineLocation::VirtualFP, Offset);
SrcML = MachineLocation(Reg);
Moves.push_back(MachineMove(CSLabel, DstML, SrcML));
}
}
}
// if framepointer enabled, set it to point to the stack pointer.
if (hasFP(MF)) {
// Insert instruction "move $fp, $sp" at this location.
BuildMI(MBB, MBBI, dl, TII.get(ADDu), FP).addReg(SP).addReg(ZERO);
// emit ".cfi_def_cfa_register $fp"
MCSymbol *SetFPLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl,
TII.get(TargetOpcode::PROLOG_LABEL)).addSym(SetFPLabel);
DstML = MachineLocation(FP);
SrcML = MachineLocation(MachineLocation::VirtualFP);
Moves.push_back(MachineMove(SetFPLabel, DstML, SrcML));
}
// Restore GP from the saved stack location
if (MipsFI->needGPSaveRestore()) {
unsigned Offset = MFI->getObjectOffset(MipsFI->getGPFI());
BuildMI(MBB, MBBI, dl, TII.get(Mips::CPRESTORE)).addImm(Offset)
.addReg(Mips::GP);
}
}
/// Insert prolog code into the function.
/// For ARC, this inserts a call to a function that puts required callee saved
/// registers onto the stack, when enough callee saved registers are required.
void ARCFrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
LLVM_DEBUG(dbgs() << "Emit Prologue: " << MF.getName() << "\n");
auto *AFI = MF.getInfo<ARCFunctionInfo>();
MachineModuleInfo &MMI = MF.getMMI();
MCContext &Context = MMI.getContext();
const MCRegisterInfo *MRI = Context.getRegisterInfo();
const ARCInstrInfo *TII = MF.getSubtarget<ARCSubtarget>().getInstrInfo();
MachineBasicBlock::iterator MBBI = MBB.begin();
// Debug location must be unknown since the first debug location is used
// to determine the end of the prologue.
DebugLoc dl;
MachineFrameInfo &MFI = MF.getFrameInfo();
const std::vector<CalleeSavedInfo> &CSI = MFI.getCalleeSavedInfo();
unsigned Last = determineLastCalleeSave(CSI);
unsigned StackSlotsUsedByFunclet = 0;
bool SavedBlink = false;
unsigned AlreadyAdjusted = 0;
if (MF.getFunction().isVarArg()) {
// Add in the varargs area here first.
LLVM_DEBUG(dbgs() << "Varargs\n");
unsigned VarArgsBytes = MFI.getObjectSize(AFI->getVarArgsFrameIndex());
BuildMI(MBB, MBBI, dl, TII->get(ARC::SUB_rru6))
.addReg(ARC::SP)
.addReg(ARC::SP)
.addImm(VarArgsBytes);
}
if (hasFP(MF)) {
LLVM_DEBUG(dbgs() << "Saving FP\n");
BuildMI(MBB, MBBI, dl, TII->get(ARC::ST_AW_rs9))
.addReg(ARC::SP, RegState::Define)
.addReg(ARC::FP)
.addReg(ARC::SP)
.addImm(-4);
AlreadyAdjusted += 4;
}
if (UseSaveRestoreFunclet && Last > ARC::R14) {
LLVM_DEBUG(dbgs() << "Creating store funclet.\n");
// BL to __save_r13_to_<TRI->getRegAsmName()>
StackSlotsUsedByFunclet = Last - ARC::R12;
BuildMI(MBB, MBBI, dl, TII->get(ARC::PUSH_S_BLINK));
BuildMI(MBB, MBBI, dl, TII->get(ARC::SUB_rru6))
.addReg(ARC::SP)
.addReg(ARC::SP)
.addImm(4 * StackSlotsUsedByFunclet);
BuildMI(MBB, MBBI, dl, TII->get(ARC::BL))
.addExternalSymbol(store_funclet_name[Last - ARC::R15])
.addReg(ARC::BLINK, RegState::Implicit | RegState::Kill);
AlreadyAdjusted += 4 * (StackSlotsUsedByFunclet + 1);
SavedBlink = true;
}
// If we haven't saved BLINK, but we need to...do that now.
if (MFI.hasCalls() && !SavedBlink) {
LLVM_DEBUG(dbgs() << "Creating save blink.\n");
BuildMI(MBB, MBBI, dl, TII->get(ARC::PUSH_S_BLINK));
AlreadyAdjusted += 4;
}
if (AFI->MaxCallStackReq > 0)
MFI.setStackSize(MFI.getStackSize() + AFI->MaxCallStackReq);
// We have already saved some of the stack...
LLVM_DEBUG(dbgs() << "Adjusting stack by: "
<< (MFI.getStackSize() - AlreadyAdjusted) << "\n");
generateStackAdjustment(MBB, MBBI, *ST.getInstrInfo(), dl,
-(MFI.getStackSize() - AlreadyAdjusted), ARC::SP);
if (hasFP(MF)) {
LLVM_DEBUG(dbgs() << "Setting FP from SP.\n");
BuildMI(MBB, MBBI, dl,
TII->get(isUInt<6>(MFI.getStackSize()) ? ARC::ADD_rru6
: ARC::ADD_rrlimm),
ARC::FP)
.addReg(ARC::SP)
.addImm(MFI.getStackSize());
}
// Emit CFI records:
// .cfi_def_cfa_offset StackSize
// .cfi_offset fp, -StackSize
// .cfi_offset blink, -StackSize+4
unsigned CFIIndex = MF.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, -MFI.getStackSize()));
BuildMI(MBB, MBBI, dl, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
int CurOffset = -4;
if (hasFP(MF)) {
CFIIndex = MF.addFrameInst(MCCFIInstruction::createOffset(
nullptr, MRI->getDwarfRegNum(ARC::FP, true), CurOffset));
BuildMI(MBB, MBBI, dl, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
CurOffset -= 4;
}
if (MFI.hasCalls()) {
CFIIndex = MF.addFrameInst(MCCFIInstruction::createOffset(
nullptr, MRI->getDwarfRegNum(ARC::BLINK, true), CurOffset));
BuildMI(MBB, MBBI, dl, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
// CFI for the rest of the registers.
for (const auto &Entry : CSI) {
unsigned Reg = Entry.getReg();
int FI = Entry.getFrameIdx();
// Skip BLINK and FP.
if ((hasFP(MF) && Reg == ARC::FP) || (MFI.hasCalls() && Reg == ARC::BLINK))
continue;
CFIIndex = MF.addFrameInst(MCCFIInstruction::createOffset(
nullptr, MRI->getDwarfRegNum(Reg, true), MFI.getObjectOffset(FI)));
BuildMI(MBB, MBBI, dl, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
}
void MipsFrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
const MipsRegisterInfo *RegInfo =
static_cast<const MipsRegisterInfo*>(MF.getTarget().getRegisterInfo());
const MipsInstrInfo &TII =
*static_cast<const MipsInstrInfo*>(MF.getTarget().getInstrInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
bool isPIC = (MF.getTarget().getRelocationModel() == Reloc::PIC_);
unsigned NewReg = 0;
int NewImm = 0;
bool ATUsed;
// First, compute final stack size.
unsigned RegSize = STI.isGP32bit() ? 4 : 8;
unsigned StackAlign = getStackAlignment();
unsigned LocalVarAreaOffset = MipsFI->needGPSaveRestore() ?
(MFI->getObjectOffset(MipsFI->getGPFI()) + RegSize) :
MipsFI->getMaxCallFrameSize();
unsigned StackSize = AlignOffset(LocalVarAreaOffset, StackAlign) +
AlignOffset(MFI->getStackSize(), StackAlign);
// Update stack size
MFI->setStackSize(StackSize);
BuildMI(MBB, MBBI, dl, TII.get(Mips::NOREORDER));
// TODO: check need from GP here.
if (isPIC && STI.isABI_O32())
BuildMI(MBB, MBBI, dl, TII.get(Mips::CPLOAD))
.addReg(RegInfo->getPICCallReg());
BuildMI(MBB, MBBI, dl, TII.get(Mips::NOMACRO));
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
// Adjust stack : addi sp, sp, (-imm)
ATUsed = expandRegLargeImmPair(Mips::SP, -StackSize, NewReg, NewImm, MBB,
MBBI);
BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDiu), Mips::SP)
.addReg(NewReg).addImm(NewImm);
// FIXME: change this when mips goes MC".
if (ATUsed)
BuildMI(MBB, MBBI, dl, TII.get(Mips::ATMACRO));
// Find the instruction past the last instruction that saves a callee-saved
// register to the stack.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
for (unsigned i = 0; i < CSI.size(); ++i)
++MBBI;
// if framepointer enabled, set it to point to the stack pointer.
if (hasFP(MF))
// Insert instruction "move $fp, $sp" at this location.
BuildMI(MBB, MBBI, dl, TII.get(Mips::ADDu), Mips::FP)
.addReg(Mips::SP).addReg(Mips::ZERO);
// Restore GP from the saved stack location
if (MipsFI->needGPSaveRestore())
BuildMI(MBB, MBBI, dl, TII.get(Mips::CPRESTORE))
.addImm(MFI->getObjectOffset(MipsFI->getGPFI()));
// EH Frame infomation.
MachineModuleInfo &MMI = MF.getMMI();
std::vector<MachineMove> &Moves = MMI.getFrameMoves();
MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::PROLOG_LABEL)).addSym(FrameLabel);
if (hasFP(MF)) {
MachineLocation SPDst(Mips::FP);
MachineLocation SPSrc(Mips::SP);
Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
}
if (StackSize) {
MachineLocation SPDst(MachineLocation::VirtualFP);
MachineLocation SPSrc(MachineLocation::VirtualFP, -StackSize);
Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
}
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
MachineLocation CSSrc(I->getReg());
Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
}
}
DenseMap<const MachineBasicBlock *, int>
llvm::getFuncletMembership(const MachineFunction &MF) {
DenseMap<const MachineBasicBlock *, int> FuncletMembership;
// We don't have anything to do if there aren't any EH pads.
if (!MF.getMMI().hasEHFunclets())
return FuncletMembership;
int EntryBBNumber = MF.front().getNumber();
bool IsSEH = isAsynchronousEHPersonality(
classifyEHPersonality(MF.getFunction()->getPersonalityFn()));
const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
SmallVector<const MachineBasicBlock *, 16> FuncletBlocks;
SmallVector<const MachineBasicBlock *, 16> UnreachableBlocks;
SmallVector<const MachineBasicBlock *, 16> SEHCatchPads;
SmallVector<std::pair<const MachineBasicBlock *, int>, 16> CatchRetSuccessors;
for (const MachineBasicBlock &MBB : MF) {
if (MBB.isEHFuncletEntry()) {
FuncletBlocks.push_back(&MBB);
} else if (IsSEH && MBB.isEHPad()) {
SEHCatchPads.push_back(&MBB);
} else if (MBB.pred_empty()) {
UnreachableBlocks.push_back(&MBB);
}
MachineBasicBlock::const_iterator MBBI = MBB.getFirstTerminator();
// CatchPads are not funclets for SEH so do not consider CatchRet to
// transfer control to another funclet.
if (MBBI->getOpcode() != TII->getCatchReturnOpcode())
continue;
// FIXME: SEH CatchPads are not necessarily in the parent function:
// they could be inside a finally block.
const MachineBasicBlock *Successor = MBBI->getOperand(0).getMBB();
const MachineBasicBlock *SuccessorColor = MBBI->getOperand(1).getMBB();
CatchRetSuccessors.push_back(
{Successor, IsSEH ? EntryBBNumber : SuccessorColor->getNumber()});
}
// We don't have anything to do if there aren't any EH pads.
if (FuncletBlocks.empty())
return FuncletMembership;
// Identify all the basic blocks reachable from the function entry.
collectFuncletMembers(FuncletMembership, EntryBBNumber, &MF.front());
// All blocks not part of a funclet are in the parent function.
for (const MachineBasicBlock *MBB : UnreachableBlocks)
collectFuncletMembers(FuncletMembership, EntryBBNumber, MBB);
// Next, identify all the blocks inside the funclets.
for (const MachineBasicBlock *MBB : FuncletBlocks)
collectFuncletMembers(FuncletMembership, MBB->getNumber(), MBB);
// SEH CatchPads aren't really funclets, handle them separately.
for (const MachineBasicBlock *MBB : SEHCatchPads)
collectFuncletMembers(FuncletMembership, EntryBBNumber, MBB);
// Finally, identify all the targets of a catchret.
for (std::pair<const MachineBasicBlock *, int> CatchRetPair :
CatchRetSuccessors)
collectFuncletMembers(FuncletMembership, CatchRetPair.second,
CatchRetPair.first);
return FuncletMembership;
}
void AArch64FrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = MBB.begin();
const MachineFrameInfo *MFI = MF.getFrameInfo();
const Function *Fn = MF.getFunction();
const AArch64Subtarget &Subtarget = MF.getSubtarget<AArch64Subtarget>();
const AArch64RegisterInfo *RegInfo = Subtarget.getRegisterInfo();
const TargetInstrInfo *TII = Subtarget.getInstrInfo();
MachineModuleInfo &MMI = MF.getMMI();
AArch64FunctionInfo *AFI = MF.getInfo<AArch64FunctionInfo>();
bool needsFrameMoves = MMI.hasDebugInfo() || Fn->needsUnwindTableEntry();
bool HasFP = hasFP(MF);
// Debug location must be unknown since the first debug location is used
// to determine the end of the prologue.
DebugLoc DL;
// All calls are tail calls in GHC calling conv, and functions have no
// prologue/epilogue.
if (MF.getFunction()->getCallingConv() == CallingConv::GHC)
return;
int NumBytes = (int)MFI->getStackSize();
if (!AFI->hasStackFrame()) {
assert(!HasFP && "unexpected function without stack frame but with FP");
// All of the stack allocation is for locals.
AFI->setLocalStackSize(NumBytes);
// Label used to tie together the PROLOG_LABEL and the MachineMoves.
MCSymbol *FrameLabel = MMI.getContext().createTempSymbol();
// REDZONE: If the stack size is less than 128 bytes, we don't need
// to actually allocate.
if (NumBytes && !canUseRedZone(MF)) {
emitFrameOffset(MBB, MBBI, DL, AArch64::SP, AArch64::SP, -NumBytes, TII,
MachineInstr::FrameSetup);
// Encode the stack size of the leaf function.
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(FrameLabel, -NumBytes));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
} else if (NumBytes) {
++NumRedZoneFunctions;
}
return;
}
// Only set up FP if we actually need to.
int FPOffset = 0;
if (HasFP)
FPOffset = getFPOffsetInPrologue(MBBI);
// Move past the saves of the callee-saved registers.
while (isCSSave(MBBI)) {
++MBBI;
NumBytes -= 16;
}
assert(NumBytes >= 0 && "Negative stack allocation size!?");
if (HasFP) {
// Issue sub fp, sp, FPOffset or
// mov fp,sp when FPOffset is zero.
// Note: All stores of callee-saved registers are marked as "FrameSetup".
// This code marks the instruction(s) that set the FP also.
emitFrameOffset(MBB, MBBI, DL, AArch64::FP, AArch64::SP, FPOffset, TII,
MachineInstr::FrameSetup);
}
// All of the remaining stack allocations are for locals.
AFI->setLocalStackSize(NumBytes);
// Allocate space for the rest of the frame.
const unsigned Alignment = MFI->getMaxAlignment();
const bool NeedsRealignment = RegInfo->needsStackRealignment(MF);
unsigned scratchSPReg = AArch64::SP;
if (NumBytes && NeedsRealignment) {
// Use the first callee-saved register as a scratch register.
scratchSPReg = AArch64::X9;
}
// If we're a leaf function, try using the red zone.
if (NumBytes && !canUseRedZone(MF))
// FIXME: in the case of dynamic re-alignment, NumBytes doesn't have
// the correct value here, as NumBytes also includes padding bytes,
// which shouldn't be counted here.
emitFrameOffset(MBB, MBBI, DL, scratchSPReg, AArch64::SP, -NumBytes, TII,
MachineInstr::FrameSetup);
if (NumBytes && NeedsRealignment) {
const unsigned NrBitsToZero = countTrailingZeros(Alignment);
assert(NrBitsToZero > 1);
assert(scratchSPReg != AArch64::SP);
// SUB X9, SP, NumBytes
// -- X9 is temporary register, so shouldn't contain any live data here,
// -- free to use. This is already produced by emitFrameOffset above.
// AND SP, X9, 0b11111...0000
// The logical immediates have a non-trivial encoding. The following
// formula computes the encoded immediate with all ones but
// NrBitsToZero zero bits as least significant bits.
uint32_t andMaskEncoded =
(1 <<12) // = N
| ((64-NrBitsToZero) << 6) // immr
| ((64-NrBitsToZero-1) << 0) // imms
;
BuildMI(MBB, MBBI, DL, TII->get(AArch64::ANDXri), AArch64::SP)
.addReg(scratchSPReg, RegState::Kill)
.addImm(andMaskEncoded);
}
// If we need a base pointer, set it up here. It's whatever the value of the
// stack pointer is at this point. Any variable size objects will be allocated
// after this, so we can still use the base pointer to reference locals.
//
// FIXME: Clarify FrameSetup flags here.
// Note: Use emitFrameOffset() like above for FP if the FrameSetup flag is
// needed.
if (RegInfo->hasBasePointer(MF)) {
TII->copyPhysReg(MBB, MBBI, DL, RegInfo->getBaseRegister(), AArch64::SP,
false);
}
if (needsFrameMoves) {
const DataLayout &TD = MF.getDataLayout();
const int StackGrowth = -TD.getPointerSize(0);
unsigned FramePtr = RegInfo->getFrameRegister(MF);
// An example of the prologue:
//
// .globl __foo
// .align 2
// __foo:
// Ltmp0:
// .cfi_startproc
// .cfi_personality 155, ___gxx_personality_v0
// Leh_func_begin:
// .cfi_lsda 16, Lexception33
//
// stp xa,bx, [sp, -#offset]!
// ...
// stp x28, x27, [sp, #offset-32]
// stp fp, lr, [sp, #offset-16]
// add fp, sp, #offset - 16
// sub sp, sp, #1360
//
// The Stack:
// +-------------------------------------------+
// 10000 | ........ | ........ | ........ | ........ |
// 10004 | ........ | ........ | ........ | ........ |
// +-------------------------------------------+
// 10008 | ........ | ........ | ........ | ........ |
// 1000c | ........ | ........ | ........ | ........ |
// +===========================================+
// 10010 | X28 Register |
// 10014 | X28 Register |
// +-------------------------------------------+
// 10018 | X27 Register |
// 1001c | X27 Register |
// +===========================================+
// 10020 | Frame Pointer |
// 10024 | Frame Pointer |
// +-------------------------------------------+
// 10028 | Link Register |
// 1002c | Link Register |
// +===========================================+
// 10030 | ........ | ........ | ........ | ........ |
// 10034 | ........ | ........ | ........ | ........ |
// +-------------------------------------------+
// 10038 | ........ | ........ | ........ | ........ |
// 1003c | ........ | ........ | ........ | ........ |
// +-------------------------------------------+
//
// [sp] = 10030 :: >>initial value<<
// sp = 10020 :: stp fp, lr, [sp, #-16]!
// fp = sp == 10020 :: mov fp, sp
// [sp] == 10020 :: stp x28, x27, [sp, #-16]!
// sp == 10010 :: >>final value<<
//
// The frame pointer (w29) points to address 10020. If we use an offset of
// '16' from 'w29', we get the CFI offsets of -8 for w30, -16 for w29, -24
// for w27, and -32 for w28:
//
// Ltmp1:
// .cfi_def_cfa w29, 16
// Ltmp2:
// .cfi_offset w30, -8
// Ltmp3:
// .cfi_offset w29, -16
// Ltmp4:
// .cfi_offset w27, -24
// Ltmp5:
// .cfi_offset w28, -32
if (HasFP) {
// Define the current CFA rule to use the provided FP.
unsigned Reg = RegInfo->getDwarfRegNum(FramePtr, true);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfa(nullptr, Reg, 2 * StackGrowth));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
// Record the location of the stored LR
unsigned LR = RegInfo->getDwarfRegNum(AArch64::LR, true);
CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, LR, StackGrowth));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
// Record the location of the stored FP
CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg, 2 * StackGrowth));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
} else {
// Encode the stack size of the leaf function.
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, -MFI->getStackSize()));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
// Now emit the moves for whatever callee saved regs we have.
emitCalleeSavedFrameMoves(MBB, MBBI, FramePtr);
}
}
void AArch64FrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front(); // Prologue goes in entry BB.
MachineBasicBlock::iterator MBBI = MBB.begin();
const MachineFrameInfo *MFI = MF.getFrameInfo();
const Function *Fn = MF.getFunction();
const AArch64RegisterInfo *RegInfo = static_cast<const AArch64RegisterInfo *>(
MF.getSubtarget().getRegisterInfo());
const TargetInstrInfo *TII = MF.getSubtarget().getInstrInfo();
MachineModuleInfo &MMI = MF.getMMI();
AArch64FunctionInfo *AFI = MF.getInfo<AArch64FunctionInfo>();
bool needsFrameMoves = MMI.hasDebugInfo() || Fn->needsUnwindTableEntry();
bool HasFP = hasFP(MF);
DebugLoc DL = MBB.findDebugLoc(MBBI);
int NumBytes = (int)MFI->getStackSize();
if (!AFI->hasStackFrame()) {
assert(!HasFP && "unexpected function without stack frame but with FP");
// All of the stack allocation is for locals.
AFI->setLocalStackSize(NumBytes);
// Label used to tie together the PROLOG_LABEL and the MachineMoves.
MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
// REDZONE: If the stack size is less than 128 bytes, we don't need
// to actually allocate.
if (NumBytes && !canUseRedZone(MF)) {
emitFrameOffset(MBB, MBBI, DL, AArch64::SP, AArch64::SP, -NumBytes, TII,
MachineInstr::FrameSetup);
// Encode the stack size of the leaf function.
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(FrameLabel, -NumBytes));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
} else if (NumBytes) {
++NumRedZoneFunctions;
}
return;
}
// Only set up FP if we actually need to.
int FPOffset = 0;
if (HasFP) {
// First instruction must a) allocate the stack and b) have an immediate
// that is a multiple of -2.
assert((MBBI->getOpcode() == AArch64::STPXpre ||
MBBI->getOpcode() == AArch64::STPDpre) &&
MBBI->getOperand(3).getReg() == AArch64::SP &&
MBBI->getOperand(4).getImm() < 0 &&
(MBBI->getOperand(4).getImm() & 1) == 0);
// Frame pointer is fp = sp - 16. Since the STPXpre subtracts the space
// required for the callee saved register area we get the frame pointer
// by addding that offset - 16 = -getImm()*8 - 2*8 = -(getImm() + 2) * 8.
FPOffset = -(MBBI->getOperand(4).getImm() + 2) * 8;
assert(FPOffset >= 0 && "Bad Framepointer Offset");
}
// Move past the saves of the callee-saved registers.
while (MBBI->getOpcode() == AArch64::STPXi ||
MBBI->getOpcode() == AArch64::STPDi ||
MBBI->getOpcode() == AArch64::STPXpre ||
MBBI->getOpcode() == AArch64::STPDpre) {
++MBBI;
NumBytes -= 16;
}
assert(NumBytes >= 0 && "Negative stack allocation size!?");
if (HasFP) {
// Issue sub fp, sp, FPOffset or
// mov fp,sp when FPOffset is zero.
// Note: All stores of callee-saved registers are marked as "FrameSetup".
// This code marks the instruction(s) that set the FP also.
emitFrameOffset(MBB, MBBI, DL, AArch64::FP, AArch64::SP, FPOffset, TII,
MachineInstr::FrameSetup);
}
// All of the remaining stack allocations are for locals.
AFI->setLocalStackSize(NumBytes);
// Allocate space for the rest of the frame.
if (NumBytes) {
// If we're a leaf function, try using the red zone.
if (!canUseRedZone(MF))
emitFrameOffset(MBB, MBBI, DL, AArch64::SP, AArch64::SP, -NumBytes, TII,
MachineInstr::FrameSetup);
}
// If we need a base pointer, set it up here. It's whatever the value of the
// stack pointer is at this point. Any variable size objects will be allocated
// after this, so we can still use the base pointer to reference locals.
//
// FIXME: Clarify FrameSetup flags here.
// Note: Use emitFrameOffset() like above for FP if the FrameSetup flag is
// needed.
//
if (RegInfo->hasBasePointer(MF))
TII->copyPhysReg(MBB, MBBI, DL, AArch64::X19, AArch64::SP, false);
if (needsFrameMoves) {
const DataLayout *TD = MF.getSubtarget().getDataLayout();
const int StackGrowth = -TD->getPointerSize(0);
unsigned FramePtr = RegInfo->getFrameRegister(MF);
// An example of the prologue:
//
// .globl __foo
// .align 2
// __foo:
// Ltmp0:
// .cfi_startproc
// .cfi_personality 155, ___gxx_personality_v0
// Leh_func_begin:
// .cfi_lsda 16, Lexception33
//
// stp xa,bx, [sp, -#offset]!
// ...
// stp x28, x27, [sp, #offset-32]
// stp fp, lr, [sp, #offset-16]
// add fp, sp, #offset - 16
// sub sp, sp, #1360
//
// The Stack:
// +-------------------------------------------+
// 10000 | ........ | ........ | ........ | ........ |
// 10004 | ........ | ........ | ........ | ........ |
// +-------------------------------------------+
// 10008 | ........ | ........ | ........ | ........ |
// 1000c | ........ | ........ | ........ | ........ |
// +===========================================+
// 10010 | X28 Register |
// 10014 | X28 Register |
// +-------------------------------------------+
// 10018 | X27 Register |
// 1001c | X27 Register |
// +===========================================+
// 10020 | Frame Pointer |
// 10024 | Frame Pointer |
// +-------------------------------------------+
// 10028 | Link Register |
// 1002c | Link Register |
// +===========================================+
// 10030 | ........ | ........ | ........ | ........ |
// 10034 | ........ | ........ | ........ | ........ |
// +-------------------------------------------+
// 10038 | ........ | ........ | ........ | ........ |
// 1003c | ........ | ........ | ........ | ........ |
// +-------------------------------------------+
//
// [sp] = 10030 :: >>initial value<<
// sp = 10020 :: stp fp, lr, [sp, #-16]!
// fp = sp == 10020 :: mov fp, sp
// [sp] == 10020 :: stp x28, x27, [sp, #-16]!
// sp == 10010 :: >>final value<<
//
// The frame pointer (w29) points to address 10020. If we use an offset of
// '16' from 'w29', we get the CFI offsets of -8 for w30, -16 for w29, -24
// for w27, and -32 for w28:
//
// Ltmp1:
// .cfi_def_cfa w29, 16
// Ltmp2:
// .cfi_offset w30, -8
// Ltmp3:
// .cfi_offset w29, -16
// Ltmp4:
// .cfi_offset w27, -24
// Ltmp5:
// .cfi_offset w28, -32
if (HasFP) {
// Define the current CFA rule to use the provided FP.
unsigned Reg = RegInfo->getDwarfRegNum(FramePtr, true);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfa(nullptr, Reg, 2 * StackGrowth));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
// Record the location of the stored LR
unsigned LR = RegInfo->getDwarfRegNum(AArch64::LR, true);
CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, LR, StackGrowth));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
// Record the location of the stored FP
CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg, 2 * StackGrowth));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
} else {
// Encode the stack size of the leaf function.
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, -MFI->getStackSize()));
BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
// Now emit the moves for whatever callee saved regs we have.
emitCalleeSavedFrameMoves(MBB, MBBI, FramePtr);
}
}
/// calculateCalleeSavedRegisters - Scan the function for modified callee saved
/// registers.
void PEI::calculateCalleeSavedRegisters(MachineFunction &F) {
const TargetRegisterInfo *RegInfo = F.getSubtarget().getRegisterInfo();
const TargetFrameLowering *TFI = F.getSubtarget().getFrameLowering();
MachineFrameInfo *MFI = F.getFrameInfo();
// Get the callee saved register list...
const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegs(&F);
// These are used to keep track the callee-save area. Initialize them.
MinCSFrameIndex = INT_MAX;
MaxCSFrameIndex = 0;
// Early exit for targets which have no callee saved registers.
if (!CSRegs || CSRegs[0] == 0)
return;
// In Naked functions we aren't going to save any registers.
if (F.getFunction()->hasFnAttribute(Attribute::Naked))
return;
std::vector<CalleeSavedInfo> CSI;
for (unsigned i = 0; CSRegs[i]; ++i) {
unsigned Reg = CSRegs[i];
// Functions which call __builtin_unwind_init get all their registers saved.
if (F.getRegInfo().isPhysRegUsed(Reg) || F.getMMI().callsUnwindInit()) {
// If the reg is modified, save it!
CSI.push_back(CalleeSavedInfo(Reg));
}
}
if (!TFI->assignCalleeSavedSpillSlots(F, RegInfo, CSI)) {
// If target doesn't implement this, use generic code.
if (CSI.empty())
return; // Early exit if no callee saved registers are modified!
unsigned NumFixedSpillSlots;
const TargetFrameLowering::SpillSlot *FixedSpillSlots =
TFI->getCalleeSavedSpillSlots(NumFixedSpillSlots);
// Now that we know which registers need to be saved and restored, allocate
// stack slots for them.
for (std::vector<CalleeSavedInfo>::iterator I = CSI.begin(), E = CSI.end();
I != E; ++I) {
unsigned Reg = I->getReg();
const TargetRegisterClass *RC = RegInfo->getMinimalPhysRegClass(Reg);
int FrameIdx;
if (RegInfo->hasReservedSpillSlot(F, Reg, FrameIdx)) {
I->setFrameIdx(FrameIdx);
continue;
}
// Check to see if this physreg must be spilled to a particular stack slot
// on this target.
const TargetFrameLowering::SpillSlot *FixedSlot = FixedSpillSlots;
while (FixedSlot != FixedSpillSlots + NumFixedSpillSlots &&
FixedSlot->Reg != Reg)
++FixedSlot;
if (FixedSlot == FixedSpillSlots + NumFixedSpillSlots) {
// Nope, just spill it anywhere convenient.
unsigned Align = RC->getAlignment();
unsigned StackAlign = TFI->getStackAlignment();
// We may not be able to satisfy the desired alignment specification of
// the TargetRegisterClass if the stack alignment is smaller. Use the
// min.
Align = std::min(Align, StackAlign);
FrameIdx = MFI->CreateStackObject(RC->getSize(), Align, true);
if ((unsigned)FrameIdx < MinCSFrameIndex) MinCSFrameIndex = FrameIdx;
if ((unsigned)FrameIdx > MaxCSFrameIndex) MaxCSFrameIndex = FrameIdx;
} else {
// Spill it to the stack where we must.
FrameIdx =
MFI->CreateFixedSpillStackObject(RC->getSize(), FixedSlot->Offset);
}
I->setFrameIdx(FrameIdx);
}
}
MFI->setCalleeSavedInfo(CSI);
}
void Thumb1FrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
const ThumbRegisterInfo *RegInfo =
static_cast<const ThumbRegisterInfo *>(STI.getRegisterInfo());
const Thumb1InstrInfo &TII =
*static_cast<const Thumb1InstrInfo *>(STI.getInstrInfo());
unsigned ArgRegsSaveSize = AFI->getArgRegsSaveSize();
unsigned NumBytes = MFI->getStackSize();
assert(NumBytes >= ArgRegsSaveSize &&
"ArgRegsSaveSize is included in NumBytes");
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
// Debug location must be unknown since the first debug location is used
// to determine the end of the prologue.
DebugLoc dl;
unsigned FramePtr = RegInfo->getFrameRegister(MF);
unsigned BasePtr = RegInfo->getBaseRegister();
int CFAOffset = 0;
// Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
NumBytes = (NumBytes + 3) & ~3;
MFI->setStackSize(NumBytes);
// Determine the sizes of each callee-save spill areas and record which frame
// belongs to which callee-save spill areas.
unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
int FramePtrSpillFI = 0;
if (ArgRegsSaveSize) {
emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -ArgRegsSaveSize,
MachineInstr::FrameSetup);
CFAOffset -= ArgRegsSaveSize;
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
if (!AFI->hasStackFrame()) {
if (NumBytes - ArgRegsSaveSize != 0) {
emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -(NumBytes - ArgRegsSaveSize),
MachineInstr::FrameSetup);
CFAOffset -= NumBytes - ArgRegsSaveSize;
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
return;
}
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
int FI = CSI[i].getFrameIdx();
switch (Reg) {
case ARM::R8:
case ARM::R9:
case ARM::R10:
case ARM::R11:
if (STI.isTargetMachO()) {
GPRCS2Size += 4;
break;
}
// fallthrough
case ARM::R4:
case ARM::R5:
case ARM::R6:
case ARM::R7:
case ARM::LR:
if (Reg == FramePtr)
FramePtrSpillFI = FI;
GPRCS1Size += 4;
break;
default:
DPRCSSize += 8;
}
}
if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) {
++MBBI;
}
// Determine starting offsets of spill areas.
unsigned DPRCSOffset = NumBytes - ArgRegsSaveSize - (GPRCS1Size + GPRCS2Size + DPRCSSize);
unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
bool HasFP = hasFP(MF);
if (HasFP)
AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
NumBytes);
AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
NumBytes = DPRCSOffset;
int FramePtrOffsetInBlock = 0;
unsigned adjustedGPRCS1Size = GPRCS1Size;
if (tryFoldSPUpdateIntoPushPop(STI, MF, std::prev(MBBI), NumBytes)) {
FramePtrOffsetInBlock = NumBytes;
adjustedGPRCS1Size += NumBytes;
NumBytes = 0;
}
if (adjustedGPRCS1Size) {
CFAOffset -= adjustedGPRCS1Size;
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
unsigned Reg = I->getReg();
int FI = I->getFrameIdx();
switch (Reg) {
case ARM::R8:
case ARM::R9:
case ARM::R10:
case ARM::R11:
case ARM::R12:
if (STI.isTargetMachO())
break;
// fallthough
case ARM::R0:
case ARM::R1:
case ARM::R2:
case ARM::R3:
case ARM::R4:
case ARM::R5:
case ARM::R6:
case ARM::R7:
case ARM::LR:
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
nullptr, MRI->getDwarfRegNum(Reg, true), MFI->getObjectOffset(FI)));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
break;
}
}
// Adjust FP so it point to the stack slot that contains the previous FP.
if (HasFP) {
FramePtrOffsetInBlock +=
MFI->getObjectOffset(FramePtrSpillFI) + GPRCS1Size + ArgRegsSaveSize;
AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tADDrSPi), FramePtr)
.addReg(ARM::SP).addImm(FramePtrOffsetInBlock / 4)
.setMIFlags(MachineInstr::FrameSetup));
if(FramePtrOffsetInBlock) {
CFAOffset += FramePtrOffsetInBlock;
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfa(
nullptr, MRI->getDwarfRegNum(FramePtr, true), CFAOffset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
} else {
unsigned CFIIndex =
MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
nullptr, MRI->getDwarfRegNum(FramePtr, true)));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
if (NumBytes > 508)
// If offset is > 508 then sp cannot be adjusted in a single instruction,
// try restoring from fp instead.
AFI->setShouldRestoreSPFromFP(true);
}
if (NumBytes) {
// Insert it after all the callee-save spills.
emitSPUpdate(MBB, MBBI, TII, dl, *RegInfo, -NumBytes,
MachineInstr::FrameSetup);
if (!HasFP) {
CFAOffset -= NumBytes;
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, CFAOffset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex)
.setMIFlags(MachineInstr::FrameSetup);
}
}
if (STI.isTargetELF() && HasFP)
MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
AFI->getFramePtrSpillOffset());
AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
// Thumb1 does not currently support dynamic stack realignment. Report a
// fatal error rather then silently generate bad code.
if (RegInfo->needsStackRealignment(MF))
report_fatal_error("Dynamic stack realignment not supported for thumb1.");
// If we need a base pointer, set it up here. It's whatever the value
// of the stack pointer is at this point. Any variable size objects
// will be allocated after this, so we can still use the base pointer
// to reference locals.
if (RegInfo->hasBasePointer(MF))
AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), BasePtr)
.addReg(ARM::SP));
// If the frame has variable sized objects then the epilogue must restore
// the sp from fp. We can assume there's an FP here since hasFP already
// checks for hasVarSizedObjects.
if (MFI->hasVarSizedObjects())
AFI->setShouldRestoreSPFromFP(true);
}
