/// determineFrameLayout - Determine the size of the frame and maximum call
/// frame size.
void HexagonFrameLowering::determineFrameLayout(MachineFunction &MF) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
// Get the number of bytes to allocate from the FrameInfo.
unsigned FrameSize = MFI->getStackSize();
// Get the alignments provided by the target.
unsigned TargetAlign = MF.getTarget().getFrameLowering()->getStackAlignment();
// Get the maximum call frame size of all the calls.
unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
// If we have dynamic alloca then maxCallFrameSize needs to be aligned so
// that allocations will be aligned.
if (MFI->hasVarSizedObjects())
maxCallFrameSize = RoundUpToAlignment(maxCallFrameSize, TargetAlign);
// Update maximum call frame size.
MFI->setMaxCallFrameSize(maxCallFrameSize);
// Include call frame size in total.
FrameSize += maxCallFrameSize;
// Make sure the frame is aligned.
FrameSize = RoundUpToAlignment(FrameSize, TargetAlign);
// Update frame info.
MFI->setStackSize(FrameSize);
}
void MIRPrinter::convert(ModuleSlotTracker &MST,
yaml::MachineFrameInfo &YamlMFI,
const MachineFrameInfo &MFI) {
YamlMFI.IsFrameAddressTaken = MFI.isFrameAddressTaken();
YamlMFI.IsReturnAddressTaken = MFI.isReturnAddressTaken();
YamlMFI.HasStackMap = MFI.hasStackMap();
YamlMFI.HasPatchPoint = MFI.hasPatchPoint();
YamlMFI.StackSize = MFI.getStackSize();
YamlMFI.OffsetAdjustment = MFI.getOffsetAdjustment();
YamlMFI.MaxAlignment = MFI.getMaxAlignment();
YamlMFI.AdjustsStack = MFI.adjustsStack();
YamlMFI.HasCalls = MFI.hasCalls();
YamlMFI.MaxCallFrameSize = MFI.getMaxCallFrameSize();
YamlMFI.HasOpaqueSPAdjustment = MFI.hasOpaqueSPAdjustment();
YamlMFI.HasVAStart = MFI.hasVAStart();
YamlMFI.HasMustTailInVarArgFunc = MFI.hasMustTailInVarArgFunc();
if (MFI.getSavePoint()) {
raw_string_ostream StrOS(YamlMFI.SavePoint.Value);
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.printMBBReference(*MFI.getSavePoint());
}
if (MFI.getRestorePoint()) {
raw_string_ostream StrOS(YamlMFI.RestorePoint.Value);
MIPrinter(StrOS, MST, RegisterMaskIds, StackObjectOperandMapping)
.printMBBReference(*MFI.getRestorePoint());
}
}
/// determineFrameLayout - Determine the size of the frame and maximum call
/// frame size.
void
SPURegisterInfo::determineFrameLayout(MachineFunction &MF) const
{
MachineFrameInfo *MFI = MF.getFrameInfo();
// Get the number of bytes to allocate from the FrameInfo
unsigned FrameSize = MFI->getStackSize();
// Get the alignments provided by the target, and the maximum alignment
// (if any) of the fixed frame objects.
unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
unsigned Align = std::max(TargetAlign, MFI->getMaxAlignment());
assert(isPowerOf2_32(Align) && "Alignment is not power of 2");
unsigned AlignMask = Align - 1;
// Get the maximum call frame size of all the calls.
unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
// If we have dynamic alloca then maxCallFrameSize needs to be aligned so
// that allocations will be aligned.
if (MFI->hasVarSizedObjects())
maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
// Update maximum call frame size.
MFI->setMaxCallFrameSize(maxCallFrameSize);
// Include call frame size in total.
FrameSize += maxCallFrameSize;
// Make sure the frame is aligned.
FrameSize = (FrameSize + AlignMask) & ~AlignMask;
// Update frame info.
MFI->setStackSize(FrameSize);
}
void MIRPrinter::convert(ModuleSlotTracker &MST,
yaml::MachineFrameInfo &YamlMFI,
const MachineFrameInfo &MFI) {
YamlMFI.IsFrameAddressTaken = MFI.isFrameAddressTaken();
YamlMFI.IsReturnAddressTaken = MFI.isReturnAddressTaken();
YamlMFI.HasStackMap = MFI.hasStackMap();
YamlMFI.HasPatchPoint = MFI.hasPatchPoint();
YamlMFI.StackSize = MFI.getStackSize();
YamlMFI.OffsetAdjustment = MFI.getOffsetAdjustment();
YamlMFI.MaxAlignment = MFI.getMaxAlignment();
YamlMFI.AdjustsStack = MFI.adjustsStack();
YamlMFI.HasCalls = MFI.hasCalls();
YamlMFI.MaxCallFrameSize = MFI.isMaxCallFrameSizeComputed()
? MFI.getMaxCallFrameSize() : ~0u;
YamlMFI.CVBytesOfCalleeSavedRegisters =
MFI.getCVBytesOfCalleeSavedRegisters();
YamlMFI.HasOpaqueSPAdjustment = MFI.hasOpaqueSPAdjustment();
YamlMFI.HasVAStart = MFI.hasVAStart();
YamlMFI.HasMustTailInVarArgFunc = MFI.hasMustTailInVarArgFunc();
YamlMFI.LocalFrameSize = MFI.getLocalFrameSize();
if (MFI.getSavePoint()) {
raw_string_ostream StrOS(YamlMFI.SavePoint.Value);
StrOS << printMBBReference(*MFI.getSavePoint());
}
if (MFI.getRestorePoint()) {
raw_string_ostream StrOS(YamlMFI.RestorePoint.Value);
StrOS << printMBBReference(*MFI.getRestorePoint());
}
}
// Determines the size of the frame and maximum call frame size.
void LanaiFrameLowering::determineFrameLayout(MachineFunction &MF) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
const LanaiRegisterInfo *LRI = STI.getRegisterInfo();
// Get the number of bytes to allocate from the FrameInfo.
unsigned FrameSize = MFI->getStackSize();
// Get the alignment.
unsigned StackAlign = LRI->needsStackRealignment(MF) ? MFI->getMaxAlignment()
: getStackAlignment();
// Get the maximum call frame size of all the calls.
unsigned MaxCallFrameSize = MFI->getMaxCallFrameSize();
// If we have dynamic alloca then MaxCallFrameSize needs to be aligned so
// that allocations will be aligned.
if (MFI->hasVarSizedObjects())
MaxCallFrameSize = alignTo(MaxCallFrameSize, StackAlign);
// Update maximum call frame size.
MFI->setMaxCallFrameSize(MaxCallFrameSize);
// Include call frame size in total.
if (!(hasReservedCallFrame(MF) && MFI->adjustsStack()))
FrameSize += MaxCallFrameSize;
// Make sure the frame is aligned.
FrameSize = alignTo(FrameSize, StackAlign);
// Update frame info.
MFI->setStackSize(FrameSize);
}
void HexagonFrameLowering::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front();
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineBasicBlock::iterator MBBI = MBB.begin();
const HexagonRegisterInfo *QRI =
MF.getSubtarget<HexagonSubtarget>().getRegisterInfo();
DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
determineFrameLayout(MF);
// 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());
}
//
// 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.getSubtarget().getInstrInfo();
if (NumBytes >= ALLOCFRAME_MAX) {
// Emit allocframe(#0).
BuildMI(MBB, InsertPt, dl, TII.get(Hexagon::S2_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::A2_sub),
QRI->getStackRegister()).
addReg(QRI->getStackRegister()).
addReg(HEXAGON_RESERVED_REG_1);
} else {
BuildMI(MBB, InsertPt, dl, TII.get(Hexagon::S2_allocframe)).addImm(NumBytes);
}
}
}
// Split ADJDYNALLOC instruction MI.
void SystemZInstrInfo::splitAdjDynAlloc(MachineBasicBlock::iterator MI) const {
MachineBasicBlock *MBB = MI->getParent();
MachineFunction &MF = *MBB->getParent();
MachineFrameInfo *MFFrame = MF.getFrameInfo();
MachineOperand &OffsetMO = MI->getOperand(2);
uint64_t Offset = (MFFrame->getMaxCallFrameSize() +
SystemZMC::CallFrameSize +
OffsetMO.getImm());
unsigned NewOpcode = getOpcodeForOffset(SystemZ::LA, Offset);
assert(NewOpcode && "No support for huge argument lists yet");
MI->setDesc(get(NewOpcode));
OffsetMO.setImm(Offset);
}
void VideoCore4FrameLowering::determineFrameLayout(MachineFunction& MF) const {
MachineFrameInfo* MFI = MF.getFrameInfo();
unsigned alignment = MF.getTarget().getFrameLowering()->getStackAlignment();
unsigned SLsize = MFI->getStackSize();
unsigned Asize = MFI->getMaxCallFrameSize();
if (MFI->hasVarSizedObjects())
Asize = RoundUpToAlignment(Asize, alignment);
MFI->setMaxCallFrameSize(Asize);
unsigned SLAsize = SLsize + Asize;
SLAsize = RoundUpToAlignment(SLAsize, alignment);
MFI->setStackSize(SLAsize);
}
void MIRPrinter::convert(yaml::MachineFrameInfo &YamlMFI,
const MachineFrameInfo &MFI) {
YamlMFI.IsFrameAddressTaken = MFI.isFrameAddressTaken();
YamlMFI.IsReturnAddressTaken = MFI.isReturnAddressTaken();
YamlMFI.HasStackMap = MFI.hasStackMap();
YamlMFI.HasPatchPoint = MFI.hasPatchPoint();
YamlMFI.StackSize = MFI.getStackSize();
YamlMFI.OffsetAdjustment = MFI.getOffsetAdjustment();
YamlMFI.MaxAlignment = MFI.getMaxAlignment();
YamlMFI.AdjustsStack = MFI.adjustsStack();
YamlMFI.HasCalls = MFI.hasCalls();
YamlMFI.MaxCallFrameSize = MFI.getMaxCallFrameSize();
YamlMFI.HasOpaqueSPAdjustment = MFI.hasOpaqueSPAdjustment();
YamlMFI.HasVAStart = MFI.hasVAStart();
YamlMFI.HasMustTailInVarArgFunc = MFI.hasMustTailInVarArgFunc();
}
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
/// abstract stack objects.
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
const TargetFrameLowering &TFI = *Fn.getTarget().getFrameLowering();
bool StackGrowsDown =
TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
// Loop over all of the stack objects, assigning sequential addresses...
MachineFrameInfo *MFI = Fn.getFrameInfo();
// Start at the beginning of the local area.
// The Offset is the distance from the stack top in the direction
// of stack growth -- so it's always nonnegative.
int LocalAreaOffset = TFI.getOffsetOfLocalArea();
if (StackGrowsDown)
LocalAreaOffset = -LocalAreaOffset;
assert(LocalAreaOffset >= 0
&& "Local area offset should be in direction of stack growth");
int64_t Offset = LocalAreaOffset;
// If there are fixed sized objects that are preallocated in the local area,
// non-fixed objects can't be allocated right at the start of local area.
// We currently don't support filling in holes in between fixed sized
// objects, so we adjust 'Offset' to point to the end of last fixed sized
// preallocated object.
for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
int64_t FixedOff;
if (StackGrowsDown) {
// The maximum distance from the stack pointer is at lower address of
// the object -- which is given by offset. For down growing stack
// the offset is negative, so we negate the offset to get the distance.
FixedOff = -MFI->getObjectOffset(i);
} else {
// The maximum distance from the start pointer is at the upper
// address of the object.
FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i);
}
if (FixedOff > Offset) Offset = FixedOff;
}
// First assign frame offsets to stack objects that are used to spill
// callee saved registers.
if (StackGrowsDown) {
for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
// If the stack grows down, we need to add the size to find the lowest
// address of the object.
Offset += MFI->getObjectSize(i);
unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
MFI->setObjectOffset(i, -Offset); // Set the computed offset
}
} else {
int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex;
for (int i = MaxCSFI; i >= MinCSFI ; --i) {
unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
MFI->setObjectOffset(i, Offset);
Offset += MFI->getObjectSize(i);
}
}
unsigned MaxAlign = MFI->getMaxAlignment();
// Make sure the special register scavenging spill slot is closest to the
// frame pointer if a frame pointer is required.
const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
if (RS && TFI.hasFP(Fn) && RegInfo->useFPForScavengingIndex(Fn) &&
!RegInfo->needsStackRealignment(Fn)) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
}
// FIXME: Once this is working, then enable flag will change to a target
// check for whether the frame is large enough to want to use virtual
// frame index registers. Functions which don't want/need this optimization
// will continue to use the existing code path.
if (MFI->getUseLocalStackAllocationBlock()) {
unsigned Align = MFI->getLocalFrameMaxAlign();
// Adjust to alignment boundary.
Offset = (Offset + Align - 1) / Align * Align;
DEBUG(dbgs() << "Local frame base offset: " << Offset << "\n");
// Resolve offsets for objects in the local block.
for (unsigned i = 0, e = MFI->getLocalFrameObjectCount(); i != e; ++i) {
std::pair<int, int64_t> Entry = MFI->getLocalFrameObjectMap(i);
int64_t FIOffset = (StackGrowsDown ? -Offset : Offset) + Entry.second;
DEBUG(dbgs() << "alloc FI(" << Entry.first << ") at SP[" <<
FIOffset << "]\n");
MFI->setObjectOffset(Entry.first, FIOffset);
}
// Allocate the local block
Offset += MFI->getLocalFrameSize();
MaxAlign = std::max(Align, MaxAlign);
}
// Make sure that the stack protector comes before the local variables on the
// stack.
SmallSet<int, 16> LargeStackObjs;
if (MFI->getStackProtectorIndex() >= 0) {
AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown,
Offset, MaxAlign);
// Assign large stack objects first.
for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
if (MFI->isObjectPreAllocated(i) &&
MFI->getUseLocalStackAllocationBlock())
continue;
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
if (RS && (int)i == RS->getScavengingFrameIndex())
continue;
if (MFI->isDeadObjectIndex(i))
continue;
if (MFI->getStackProtectorIndex() == (int)i)
continue;
if (!MFI->MayNeedStackProtector(i))
continue;
AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
LargeStackObjs.insert(i);
}
}
// Then assign frame offsets to stack objects that are not used to spill
// callee saved registers.
for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
if (MFI->isObjectPreAllocated(i) &&
MFI->getUseLocalStackAllocationBlock())
continue;
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
if (RS && (int)i == RS->getScavengingFrameIndex())
continue;
if (MFI->isDeadObjectIndex(i))
continue;
if (MFI->getStackProtectorIndex() == (int)i)
continue;
if (LargeStackObjs.count(i))
continue;
AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
}
// Make sure the special register scavenging spill slot is closest to the
// stack pointer.
if (RS && (!TFI.hasFP(Fn) || RegInfo->needsStackRealignment(Fn) ||
!RegInfo->useFPForScavengingIndex(Fn))) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
}
if (!TFI.targetHandlesStackFrameRounding()) {
// If we have reserved argument space for call sites in the function
// immediately on entry to the current function, count it as part of the
// overall stack size.
if (MFI->adjustsStack() && TFI.hasReservedCallFrame(Fn))
Offset += MFI->getMaxCallFrameSize();
// Round up the size to a multiple of the alignment. If the function has
// any calls or alloca's, align to the target's StackAlignment value to
// ensure that the callee's frame or the alloca data is suitably aligned;
// otherwise, for leaf functions, align to the TransientStackAlignment
// value.
unsigned StackAlign;
if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
(RegInfo->needsStackRealignment(Fn) && MFI->getObjectIndexEnd() != 0))
StackAlign = TFI.getStackAlignment();
else
StackAlign = TFI.getTransientStackAlignment();
// If the frame pointer is eliminated, all frame offsets will be relative to
// SP not FP. Align to MaxAlign so this works.
StackAlign = std::max(StackAlign, MaxAlign);
unsigned AlignMask = StackAlign - 1;
Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
}
// Update frame info to pretend that this is part of the stack...
int64_t StackSize = Offset - LocalAreaOffset;
MFI->setStackSize(StackSize);
NumBytesStackSpace += StackSize;
}
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);
}
}
}
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
/// abstract stack objects.
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
const TargetFrameInfo &TFI = *Fn.getTarget().getFrameInfo();
bool StackGrowsDown =
TFI.getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;
// Loop over all of the stack objects, assigning sequential addresses...
MachineFrameInfo *MFI = Fn.getFrameInfo();
// Start at the beginning of the local area.
// The Offset is the distance from the stack top in the direction
// of stack growth -- so it's always nonnegative.
int LocalAreaOffset = TFI.getOffsetOfLocalArea();
if (StackGrowsDown)
LocalAreaOffset = -LocalAreaOffset;
assert(LocalAreaOffset >= 0
&& "Local area offset should be in direction of stack growth");
int64_t Offset = LocalAreaOffset;
// If there are fixed sized objects that are preallocated in the local area,
// non-fixed objects can't be allocated right at the start of local area.
// We currently don't support filling in holes in between fixed sized
// objects, so we adjust 'Offset' to point to the end of last fixed sized
// preallocated object.
for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
int64_t FixedOff;
if (StackGrowsDown) {
// The maximum distance from the stack pointer is at lower address of
// the object -- which is given by offset. For down growing stack
// the offset is negative, so we negate the offset to get the distance.
FixedOff = -MFI->getObjectOffset(i);
} else {
// The maximum distance from the start pointer is at the upper
// address of the object.
FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i);
}
if (FixedOff > Offset) Offset = FixedOff;
}
// First assign frame offsets to stack objects that are used to spill
// callee saved registers.
if (StackGrowsDown) {
for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
// If the stack grows down, we need to add the size to find the lowest
// address of the object.
Offset += MFI->getObjectSize(i);
unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
MFI->setObjectOffset(i, -Offset); // Set the computed offset
}
} else {
int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex;
for (int i = MaxCSFI; i >= MinCSFI ; --i) {
unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
MFI->setObjectOffset(i, Offset);
Offset += MFI->getObjectSize(i);
}
}
unsigned MaxAlign = MFI->getMaxAlignment();
// Make sure the special register scavenging spill slot is closest to the
// frame pointer if a frame pointer is required.
const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
if (RS && RegInfo->hasFP(Fn) && !RegInfo->needsStackRealignment(Fn)) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
}
// Make sure that the stack protector comes before the local variables on the
// stack.
if (MFI->getStackProtectorIndex() >= 0)
AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown,
Offset, MaxAlign);
// Then assign frame offsets to stack objects that are not used to spill
// callee saved registers.
for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
if (RS && (int)i == RS->getScavengingFrameIndex())
continue;
if (MFI->isDeadObjectIndex(i))
continue;
if (MFI->getStackProtectorIndex() == (int)i)
continue;
AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign);
}
// Make sure the special register scavenging spill slot is closest to the
// stack pointer.
if (RS && (!RegInfo->hasFP(Fn) || RegInfo->needsStackRealignment(Fn))) {
int SFI = RS->getScavengingFrameIndex();
if (SFI >= 0)
AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign);
}
if (!RegInfo->targetHandlesStackFrameRounding()) {
// If we have reserved argument space for call sites in the function
// immediately on entry to the current function, count it as part of the
// overall stack size.
if (MFI->adjustsStack() && RegInfo->hasReservedCallFrame(Fn))
Offset += MFI->getMaxCallFrameSize();
// Round up the size to a multiple of the alignment. If the function has
// any calls or alloca's, align to the target's StackAlignment value to
// ensure that the callee's frame or the alloca data is suitably aligned;
// otherwise, for leaf functions, align to the TransientStackAlignment
// value.
unsigned StackAlign;
if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
(RegInfo->needsStackRealignment(Fn) && MFI->getObjectIndexEnd() != 0))
StackAlign = TFI.getStackAlignment();
else
StackAlign = TFI.getTransientStackAlignment();
// If the frame pointer is eliminated, all frame offsets will be relative to
// SP not FP. Align to MaxAlign so this works.
StackAlign = std::max(StackAlign, MaxAlign);
unsigned AlignMask = StackAlign - 1;
Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
}
// Update frame info to pretend that this is part of the stack...
MFI->setStackSize(Offset - LocalAreaOffset);
}
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
/// abstract stack objects.
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering();
StackProtector *SP = &getAnalysis<StackProtector>();
bool StackGrowsDown =
TFI.getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown;
// Loop over all of the stack objects, assigning sequential addresses...
MachineFrameInfo *MFI = Fn.getFrameInfo();
// Start at the beginning of the local area.
// The Offset is the distance from the stack top in the direction
// of stack growth -- so it's always nonnegative.
int LocalAreaOffset = TFI.getOffsetOfLocalArea();
if (StackGrowsDown)
LocalAreaOffset = -LocalAreaOffset;
assert(LocalAreaOffset >= 0
&& "Local area offset should be in direction of stack growth");
int64_t Offset = LocalAreaOffset;
// Skew to be applied to alignment.
unsigned Skew = TFI.getStackAlignmentSkew(Fn);
// If there are fixed sized objects that are preallocated in the local area,
// non-fixed objects can't be allocated right at the start of local area.
// We currently don't support filling in holes in between fixed sized
// objects, so we adjust 'Offset' to point to the end of last fixed sized
// preallocated object.
for (int i = MFI->getObjectIndexBegin(); i != 0; ++i) {
int64_t FixedOff;
if (StackGrowsDown) {
// The maximum distance from the stack pointer is at lower address of
// the object -- which is given by offset. For down growing stack
// the offset is negative, so we negate the offset to get the distance.
FixedOff = -MFI->getObjectOffset(i);
} else {
// The maximum distance from the start pointer is at the upper
// address of the object.
FixedOff = MFI->getObjectOffset(i) + MFI->getObjectSize(i);
}
if (FixedOff > Offset) Offset = FixedOff;
}
// First assign frame offsets to stack objects that are used to spill
// callee saved registers.
if (StackGrowsDown) {
for (unsigned i = MinCSFrameIndex; i <= MaxCSFrameIndex; ++i) {
// If the stack grows down, we need to add the size to find the lowest
// address of the object.
Offset += MFI->getObjectSize(i);
unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = alignTo(Offset, Align, Skew);
DEBUG(dbgs() << "alloc FI(" << i << ") at SP[" << -Offset << "]\n");
MFI->setObjectOffset(i, -Offset); // Set the computed offset
}
} else {
int MaxCSFI = MaxCSFrameIndex, MinCSFI = MinCSFrameIndex;
for (int i = MaxCSFI; i >= MinCSFI ; --i) {
unsigned Align = MFI->getObjectAlignment(i);
// Adjust to alignment boundary
Offset = alignTo(Offset, Align, Skew);
DEBUG(dbgs() << "alloc FI(" << i << ") at SP[" << Offset << "]\n");
MFI->setObjectOffset(i, Offset);
Offset += MFI->getObjectSize(i);
}
}
unsigned MaxAlign = MFI->getMaxAlignment();
// Make sure the special register scavenging spill slot is closest to the
// incoming stack pointer if a frame pointer is required and is closer
// to the incoming rather than the final stack pointer.
const TargetRegisterInfo *RegInfo = Fn.getSubtarget().getRegisterInfo();
bool EarlyScavengingSlots = (TFI.hasFP(Fn) &&
TFI.isFPCloseToIncomingSP() &&
RegInfo->useFPForScavengingIndex(Fn) &&
!RegInfo->needsStackRealignment(Fn));
if (RS && EarlyScavengingSlots) {
SmallVector<int, 2> SFIs;
RS->getScavengingFrameIndices(SFIs);
for (SmallVectorImpl<int>::iterator I = SFIs.begin(),
IE = SFIs.end(); I != IE; ++I)
AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign, Skew);
}
// FIXME: Once this is working, then enable flag will change to a target
// check for whether the frame is large enough to want to use virtual
// frame index registers. Functions which don't want/need this optimization
// will continue to use the existing code path.
if (MFI->getUseLocalStackAllocationBlock()) {
unsigned Align = MFI->getLocalFrameMaxAlign();
// Adjust to alignment boundary.
Offset = alignTo(Offset, Align, Skew);
DEBUG(dbgs() << "Local frame base offset: " << Offset << "\n");
// Resolve offsets for objects in the local block.
for (unsigned i = 0, e = MFI->getLocalFrameObjectCount(); i != e; ++i) {
std::pair<int, int64_t> Entry = MFI->getLocalFrameObjectMap(i);
int64_t FIOffset = (StackGrowsDown ? -Offset : Offset) + Entry.second;
DEBUG(dbgs() << "alloc FI(" << Entry.first << ") at SP[" <<
FIOffset << "]\n");
MFI->setObjectOffset(Entry.first, FIOffset);
}
// Allocate the local block
Offset += MFI->getLocalFrameSize();
MaxAlign = std::max(Align, MaxAlign);
}
// Make sure that the stack protector comes before the local variables on the
// stack.
SmallSet<int, 16> ProtectedObjs;
if (MFI->getStackProtectorIndex() >= 0) {
StackObjSet LargeArrayObjs;
StackObjSet SmallArrayObjs;
StackObjSet AddrOfObjs;
AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown,
Offset, MaxAlign, Skew);
// Assign large stack objects first.
for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
if (MFI->isObjectPreAllocated(i) &&
MFI->getUseLocalStackAllocationBlock())
continue;
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
if (RS && RS->isScavengingFrameIndex((int)i))
continue;
if (MFI->isDeadObjectIndex(i))
continue;
if (MFI->getStackProtectorIndex() == (int)i)
continue;
switch (SP->getSSPLayout(MFI->getObjectAllocation(i))) {
case StackProtector::SSPLK_None:
continue;
case StackProtector::SSPLK_SmallArray:
SmallArrayObjs.insert(i);
continue;
case StackProtector::SSPLK_AddrOf:
AddrOfObjs.insert(i);
continue;
case StackProtector::SSPLK_LargeArray:
LargeArrayObjs.insert(i);
continue;
}
llvm_unreachable("Unexpected SSPLayoutKind.");
}
AssignProtectedObjSet(LargeArrayObjs, ProtectedObjs, MFI, StackGrowsDown,
Offset, MaxAlign, Skew);
AssignProtectedObjSet(SmallArrayObjs, ProtectedObjs, MFI, StackGrowsDown,
Offset, MaxAlign, Skew);
AssignProtectedObjSet(AddrOfObjs, ProtectedObjs, MFI, StackGrowsDown,
Offset, MaxAlign, Skew);
}
SmallVector<int, 8> ObjectsToAllocate;
int EHRegNodeFrameIndex = INT_MAX;
if (const WinEHFuncInfo *FuncInfo = Fn.getWinEHFuncInfo())
EHRegNodeFrameIndex = FuncInfo->EHRegNodeFrameIndex;
// Then prepare to assign frame offsets to stack objects that are not used to
// spill callee saved registers.
for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) {
if (MFI->isObjectPreAllocated(i) &&
MFI->getUseLocalStackAllocationBlock())
continue;
if (i >= MinCSFrameIndex && i <= MaxCSFrameIndex)
continue;
if (RS && RS->isScavengingFrameIndex((int)i))
continue;
if (MFI->isDeadObjectIndex(i))
continue;
if (MFI->getStackProtectorIndex() == (int)i)
continue;
if (EHRegNodeFrameIndex == (int)i)
continue;
if (ProtectedObjs.count(i))
continue;
// Add the objects that we need to allocate to our working set.
ObjectsToAllocate.push_back(i);
}
// Allocate the EH registration node first if one is present.
if (EHRegNodeFrameIndex != INT_MAX)
AdjustStackOffset(MFI, EHRegNodeFrameIndex, StackGrowsDown, Offset,
MaxAlign, Skew);
// Give the targets a chance to order the objects the way they like it.
if (Fn.getTarget().getOptLevel() != CodeGenOpt::None &&
Fn.getTarget().Options.StackSymbolOrdering)
TFI.orderFrameObjects(Fn, ObjectsToAllocate);
// Now walk the objects and actually assign base offsets to them.
for (auto &Object : ObjectsToAllocate)
AdjustStackOffset(MFI, Object, StackGrowsDown, Offset, MaxAlign, Skew);
// Make sure the special register scavenging spill slot is closest to the
// stack pointer.
if (RS && !EarlyScavengingSlots) {
SmallVector<int, 2> SFIs;
RS->getScavengingFrameIndices(SFIs);
for (SmallVectorImpl<int>::iterator I = SFIs.begin(),
IE = SFIs.end(); I != IE; ++I)
AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign, Skew);
}
if (!TFI.targetHandlesStackFrameRounding()) {
// If we have reserved argument space for call sites in the function
// immediately on entry to the current function, count it as part of the
// overall stack size.
if (MFI->adjustsStack() && TFI.hasReservedCallFrame(Fn))
Offset += MFI->getMaxCallFrameSize();
// Round up the size to a multiple of the alignment. If the function has
// any calls or alloca's, align to the target's StackAlignment value to
// ensure that the callee's frame or the alloca data is suitably aligned;
// otherwise, for leaf functions, align to the TransientStackAlignment
// value.
unsigned StackAlign;
if (MFI->adjustsStack() || MFI->hasVarSizedObjects() ||
(RegInfo->needsStackRealignment(Fn) && MFI->getObjectIndexEnd() != 0))
StackAlign = TFI.getStackAlignment();
else
StackAlign = TFI.getTransientStackAlignment();
// If the frame pointer is eliminated, all frame offsets will be relative to
// SP not FP. Align to MaxAlign so this works.
StackAlign = std::max(StackAlign, MaxAlign);
Offset = alignTo(Offset, StackAlign, Skew);
}
// Update frame info to pretend that this is part of the stack...
int64_t StackSize = Offset - LocalAreaOffset;
MFI->setStackSize(StackSize);
NumBytesStackSpace += StackSize;
}
