// FIXME: completely move here.
extern cl::opt<bool> ForceStackAlign;
+X86FrameLowering::X86FrameLowering(const X86Subtarget &STI,
+ unsigned StackAlignOverride)
+ : TargetFrameLowering(StackGrowsDown, StackAlignOverride,
+ STI.is64Bit() ? -8 : -4),
+ STI(STI), TII(*STI.getInstrInfo()), TRI(STI.getRegisterInfo()) {
+ // Cache a bunch of frame-related predicates for this subtarget.
+ SlotSize = TRI->getSlotSize();
+ Is64Bit = STI.is64Bit();
+ IsLP64 = STI.isTarget64BitLP64();
+ // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
+ Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
+ StackPtr = TRI->getStackRegister();
+}
+
bool X86FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
return !MF.getFrameInfo()->hasVarSizedObjects() &&
!MF.getInfo<X86MachineFunctionInfo>()->getHasPushSequences();
/// Use a more nuanced condition.
bool
X86FrameLowering::canSimplifyCallFramePseudos(const MachineFunction &MF) const {
- const X86RegisterInfo *TRI = static_cast<const X86RegisterInfo *>
- (MF.getSubtarget().getRegisterInfo());
return hasReservedCallFrame(MF) ||
- (hasFP(MF) && !TRI->needsStackRealignment(MF))
- || TRI->hasBasePointer(MF);
+ (hasFP(MF) && !TRI->needsStackRealignment(MF)) ||
+ TRI->hasBasePointer(MF);
}
// needsFrameIndexResolution - Do we need to perform FI resolution for
bool X86FrameLowering::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const MachineModuleInfo &MMI = MF.getMMI();
- const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
return (MF.getTarget().Options.DisableFramePointerElim(MF) ||
- RegInfo->needsStackRealignment(MF) ||
+ TRI->needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
- MFI->isFrameAddressTaken() || MFI->hasInlineAsmWithSPAdjust() ||
+ MFI->isFrameAddressTaken() || MFI->hasOpaqueSPAdjustment() ||
MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
MMI.callsUnwindInit() || MMI.callsEHReturn() ||
MFI->hasStackMap() || MFI->hasPatchPoint());
/// to this register without worry about clobbering it.
static unsigned findDeadCallerSavedReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
- const TargetRegisterInfo &TRI,
+ const TargetRegisterInfo *TRI,
bool Is64Bit) {
const MachineFunction *MF = MBB.getParent();
const Function *F = MF->getFunction();
unsigned Reg = MO.getReg();
if (!Reg)
continue;
- for (MCRegAliasIterator AI(Reg, &TRI, true); AI.isValid(); ++AI)
+ for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
Uses.insert(*AI);
}
return false;
}
+/// Check whether or not the terminators of \p MBB needs to read EFLAGS.
+static bool terminatorsNeedFlagsAsInput(const MachineBasicBlock &MBB) {
+ for (const MachineInstr &MI : MBB.terminators()) {
+ bool BreakNext = false;
+ for (const MachineOperand &MO : MI.operands()) {
+ if (!MO.isReg())
+ continue;
+ unsigned Reg = MO.getReg();
+ if (Reg != X86::EFLAGS)
+ continue;
+
+ // This terminator needs an eflag that is not defined
+ // by a previous terminator.
+ if (!MO.isDef())
+ return true;
+ BreakNext = true;
+ }
+ if (BreakNext)
+ break;
+ }
+ return false;
+}
+
/// emitSPUpdate - Emit a series of instructions to increment / decrement the
/// stack pointer by a constant value.
void X86FrameLowering::emitSPUpdate(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr, int64_t NumBytes,
- bool Is64BitTarget, bool Is64BitStackPtr,
- bool UseLEA, const TargetInstrInfo &TII,
- const TargetRegisterInfo &TRI) {
+ int64_t NumBytes, bool InEpilogue) const {
bool isSub = NumBytes < 0;
uint64_t Offset = isSub ? -NumBytes : NumBytes;
- unsigned Opc;
- if (UseLEA)
- Opc = getLEArOpcode(Is64BitStackPtr);
- else
- Opc = isSub
- ? getSUBriOpcode(Is64BitStackPtr, Offset)
- : getADDriOpcode(Is64BitStackPtr, Offset);
uint64_t Chunk = (1LL << 31) - 1;
DebugLoc DL = MBB.findDebugLoc(MBBI);
unsigned Reg = 0;
if (isSub && !isEAXLiveIn(*MBB.getParent()))
- Reg = (unsigned)(Is64BitTarget ? X86::RAX : X86::EAX);
+ Reg = (unsigned)(Is64Bit ? X86::RAX : X86::EAX);
else
- Reg = findDeadCallerSavedReg(MBB, MBBI, TRI, Is64BitTarget);
+ Reg = findDeadCallerSavedReg(MBB, MBBI, TRI, Is64Bit);
if (Reg) {
- Opc = Is64BitTarget ? X86::MOV64ri : X86::MOV32ri;
+ unsigned Opc = Is64Bit ? X86::MOV64ri : X86::MOV32ri;
BuildMI(MBB, MBBI, DL, TII.get(Opc), Reg)
.addImm(Offset);
Opc = isSub
- ? getSUBrrOpcode(Is64BitTarget)
- : getADDrrOpcode(Is64BitTarget);
+ ? getSUBrrOpcode(Is64Bit)
+ : getADDrrOpcode(Is64Bit);
MachineInstr *MI = BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
.addReg(StackPtr)
.addReg(Reg);
}
uint64_t ThisVal = std::min(Offset, Chunk);
- if (ThisVal == (Is64BitTarget ? 8 : 4)) {
+ if (ThisVal == (Is64Bit ? 8 : 4)) {
// Use push / pop instead.
unsigned Reg = isSub
- ? (unsigned)(Is64BitTarget ? X86::RAX : X86::EAX)
- : findDeadCallerSavedReg(MBB, MBBI, TRI, Is64BitTarget);
+ ? (unsigned)(Is64Bit ? X86::RAX : X86::EAX)
+ : findDeadCallerSavedReg(MBB, MBBI, TRI, Is64Bit);
if (Reg) {
- Opc = isSub
- ? (Is64BitTarget ? X86::PUSH64r : X86::PUSH32r)
- : (Is64BitTarget ? X86::POP64r : X86::POP32r);
+ unsigned Opc = isSub
+ ? (Is64Bit ? X86::PUSH64r : X86::PUSH32r)
+ : (Is64Bit ? X86::POP64r : X86::POP32r);
MachineInstr *MI = BuildMI(MBB, MBBI, DL, TII.get(Opc))
.addReg(Reg, getDefRegState(!isSub) | getUndefRegState(isSub));
if (isSub)
}
}
- MachineInstr *MI = nullptr;
-
- if (UseLEA) {
- MI = addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr),
- StackPtr, false, isSub ? -ThisVal : ThisVal);
- } else {
- MI = BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
- .addReg(StackPtr)
- .addImm(ThisVal);
- MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
- }
-
+ MachineInstrBuilder MI = BuildStackAdjustment(
+ MBB, MBBI, DL, isSub ? -ThisVal : ThisVal, InEpilogue);
if (isSub)
- MI->setFlag(MachineInstr::FrameSetup);
+ MI.setMIFlag(MachineInstr::FrameSetup);
Offset -= ThisVal;
}
}
+MachineInstrBuilder X86FrameLowering::BuildStackAdjustment(
+ MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI, DebugLoc DL,
+ int64_t Offset, bool InEpilogue) const {
+ assert(Offset != 0 && "zero offset stack adjustment requested");
+
+ // On Atom, using LEA to adjust SP is preferred, but using it in the epilogue
+ // is tricky.
+ bool UseLEA;
+ if (!InEpilogue) {
+ UseLEA = STI.useLeaForSP();
+ } else {
+ // If we can use LEA for SP but we shouldn't, check that none
+ // of the terminators uses the eflags. Otherwise we will insert
+ // a ADD that will redefine the eflags and break the condition.
+ // Alternatively, we could move the ADD, but this may not be possible
+ // and is an optimization anyway.
+ UseLEA = canUseLEAForSPInEpilogue(*MBB.getParent());
+ if (UseLEA && !STI.useLeaForSP())
+ UseLEA = terminatorsNeedFlagsAsInput(MBB);
+ // If that assert breaks, that means we do not do the right thing
+ // in canUseAsEpilogue.
+ assert((UseLEA || !terminatorsNeedFlagsAsInput(MBB)) &&
+ "We shouldn't have allowed this insertion point");
+ }
+
+ MachineInstrBuilder MI;
+ if (UseLEA) {
+ MI = addRegOffset(BuildMI(MBB, MBBI, DL,
+ TII.get(getLEArOpcode(Uses64BitFramePtr)),
+ StackPtr),
+ StackPtr, false, Offset);
+ } else {
+ bool IsSub = Offset < 0;
+ uint64_t AbsOffset = IsSub ? -Offset : Offset;
+ unsigned Opc = IsSub ? getSUBriOpcode(Uses64BitFramePtr, AbsOffset)
+ : getADDriOpcode(Uses64BitFramePtr, AbsOffset);
+ MI = BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
+ .addReg(StackPtr)
+ .addImm(AbsOffset);
+ MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
+ }
+ return MI;
+}
+
/// mergeSPUpdatesUp - Merge two stack-manipulating instructions upper iterator.
static
void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
int X86FrameLowering::mergeSPUpdates(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr,
- bool doMergeWithPrevious) {
+ bool doMergeWithPrevious) const {
if ((doMergeWithPrevious && MBBI == MBB.begin()) ||
(!doMergeWithPrevious && MBBI == MBB.end()))
return 0;
return Offset;
}
-/// Wraps up getting a CFI index and building a MachineInstr for it.
-static void BuildCFI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
- DebugLoc DL, const TargetInstrInfo &TII,
- MCCFIInstruction CFIInst) {
+void X86FrameLowering::BuildCFI(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI, DebugLoc DL,
+ MCCFIInstruction CFIInst) const {
MachineFunction &MF = *MBB.getParent();
unsigned CFIIndex = MF.getMMI().addFrameInst(CFIInst);
BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
- const TargetInstrInfo &TII = *MF.getSubtarget().getInstrInfo();
// Add callee saved registers to move list.
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
unsigned Reg = I->getReg();
unsigned DwarfReg = MRI->getDwarfRegNum(Reg, true);
- BuildCFI(MBB, MBBI, DL, TII,
+ BuildCFI(MBB, MBBI, DL,
MCCFIInstruction::createOffset(nullptr, DwarfReg, Offset));
}
}
void X86FrameLowering::emitStackProbeCall(MachineFunction &MF,
MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI,
- DebugLoc DL) {
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
- bool Is64Bit = STI.is64Bit();
+ DebugLoc DL) const {
bool IsLargeCodeModel = MF.getTarget().getCodeModel() == CodeModel::Large;
unsigned CallOp;
// info, we need to know the ABI stack alignment as well in case we
// have a call out. Otherwise just make sure we have some alignment - we'll
// go with the minimum SlotSize.
-static uint64_t calculateMaxStackAlign(const MachineFunction &MF) {
+uint64_t X86FrameLowering::calculateMaxStackAlign(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
uint64_t MaxAlign = MFI->getMaxAlignment(); // Desired stack alignment.
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const X86RegisterInfo *RegInfo = STI.getRegisterInfo();
- unsigned SlotSize = RegInfo->getSlotSize();
- unsigned StackAlign = STI.getFrameLowering()->getStackAlignment();
+ unsigned StackAlign = getStackAlignment();
if (ForceStackAlign) {
if (MFI->hasCalls())
MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
return MaxAlign;
}
+void X86FrameLowering::BuildStackAlignAND(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI,
+ DebugLoc DL,
+ uint64_t MaxAlign) const {
+ uint64_t Val = -MaxAlign;
+ MachineInstr *MI =
+ BuildMI(MBB, MBBI, DL, TII.get(getANDriOpcode(Uses64BitFramePtr, Val)),
+ StackPtr)
+ .addReg(StackPtr)
+ .addImm(Val)
+ .setMIFlag(MachineInstr::FrameSetup);
+
+ // The EFLAGS implicit def is dead.
+ MI->getOperand(3).setIsDead();
+}
+
/// emitPrologue - Push callee-saved registers onto the stack, which
/// automatically adjust the stack pointer. Adjust the stack pointer to allocate
/// space for local variables. Also emit labels used by the exception handler to
void X86FrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
+ assert(&STI == &MF.getSubtarget<X86Subtarget>() &&
+ "MF used frame lowering for wrong subtarget");
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
const Function *Fn = MF.getFunction();
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const X86RegisterInfo *RegInfo = STI.getRegisterInfo();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
MachineModuleInfo &MMI = MF.getMMI();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
uint64_t MaxAlign = calculateMaxStackAlign(MF); // Desired stack alignment.
uint64_t StackSize = MFI->getStackSize(); // Number of bytes to allocate.
bool HasFP = hasFP(MF);
- bool Is64Bit = STI.is64Bit();
- // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
- const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
bool IsWin64CC = STI.isCallingConvWin64(Fn->getCallingConv());
- // Not necessarily synonymous with IsWin64CC.
bool IsWin64Prologue = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
bool NeedsWinCFI = IsWin64Prologue && Fn->needsUnwindTableEntry();
bool NeedsDwarfCFI =
!IsWin64Prologue && (MMI.hasDebugInfo() || Fn->needsUnwindTableEntry());
- bool UseLEA = STI.useLeaForSP();
- unsigned SlotSize = RegInfo->getSlotSize();
- unsigned FramePtr = RegInfo->getFrameRegister(MF);
+ unsigned FramePtr = TRI->getFrameRegister(MF);
const unsigned MachineFramePtr =
STI.isTarget64BitILP32()
? getX86SubSuperRegister(FramePtr, MVT::i64, false)
: FramePtr;
- unsigned StackPtr = RegInfo->getStackRegister();
- unsigned BasePtr = RegInfo->getBaseRegister();
+ unsigned BasePtr = TRI->getBaseRegister();
DebugLoc DL;
// Add RETADDR move area to callee saved frame size.
// stack pointer (we fit in the Red Zone). We also check that we don't
// push and pop from the stack.
if (Is64Bit && !Fn->hasFnAttribute(Attribute::NoRedZone) &&
- !RegInfo->needsStackRealignment(MF) &&
+ !TRI->needsStackRealignment(MF) &&
!MFI->hasVarSizedObjects() && // No dynamic alloca.
!MFI->adjustsStack() && // No calls.
!IsWin64CC && // Win64 has no Red Zone
// applies to tail call optimized functions where the callee argument stack
// size is bigger than the callers.
if (TailCallReturnAddrDelta < 0) {
- MachineInstr *MI =
- BuildMI(MBB, MBBI, DL,
- TII.get(getSUBriOpcode(Uses64BitFramePtr, -TailCallReturnAddrDelta)),
- StackPtr)
- .addReg(StackPtr)
- .addImm(-TailCallReturnAddrDelta)
+ BuildStackAdjustment(MBB, MBBI, DL, TailCallReturnAddrDelta,
+ /*InEpilogue=*/false)
.setMIFlag(MachineInstr::FrameSetup);
- MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
}
// Mapping for machine moves:
NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize();
// Callee-saved registers are pushed on stack before the stack is realigned.
- if (RegInfo->needsStackRealignment(MF) && !IsWin64Prologue)
+ if (TRI->needsStackRealignment(MF) && !IsWin64Prologue)
NumBytes = RoundUpToAlignment(NumBytes, MaxAlign);
// Get the offset of the stack slot for the EBP register, which is
// Mark the place where EBP/RBP was saved.
// Define the current CFA rule to use the provided offset.
assert(StackSize);
- BuildCFI(MBB, MBBI, DL, TII,
+ BuildCFI(MBB, MBBI, DL,
MCCFIInstruction::createDefCfaOffset(nullptr, 2 * stackGrowth));
// Change the rule for the FramePtr to be an "offset" rule.
- unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(MachineFramePtr, true);
- BuildCFI(MBB, MBBI, DL, TII,
- MCCFIInstruction::createOffset(nullptr, DwarfFramePtr,
- 2 * stackGrowth));
+ unsigned DwarfFramePtr = TRI->getDwarfRegNum(MachineFramePtr, true);
+ BuildCFI(MBB, MBBI, DL, MCCFIInstruction::createOffset(
+ nullptr, DwarfFramePtr, 2 * stackGrowth));
}
if (NeedsWinCFI) {
if (NeedsDwarfCFI) {
// Mark effective beginning of when frame pointer becomes valid.
// Define the current CFA to use the EBP/RBP register.
- unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(MachineFramePtr, true);
- BuildCFI(MBB, MBBI, DL, TII,
+ unsigned DwarfFramePtr = TRI->getDwarfRegNum(MachineFramePtr, true);
+ BuildCFI(MBB, MBBI, DL,
MCCFIInstruction::createDefCfaRegister(nullptr, DwarfFramePtr));
}
int StackOffset = 2 * stackGrowth;
while (MBBI != MBB.end() &&
+ MBBI->getFlag(MachineInstr::FrameSetup) &&
(MBBI->getOpcode() == X86::PUSH32r ||
MBBI->getOpcode() == X86::PUSH64r)) {
PushedRegs = true;
// Mark callee-saved push instruction.
// Define the current CFA rule to use the provided offset.
assert(StackSize);
- BuildCFI(MBB, MBBI, DL, TII,
+ BuildCFI(MBB, MBBI, DL,
MCCFIInstruction::createDefCfaOffset(nullptr, StackOffset));
StackOffset += stackGrowth;
}
// Realign stack after we pushed callee-saved registers (so that we'll be
// able to calculate their offsets from the frame pointer).
// Don't do this for Win64, it needs to realign the stack after the prologue.
- if (!IsWin64Prologue && RegInfo->needsStackRealignment(MF)) {
+ if (!IsWin64Prologue && TRI->needsStackRealignment(MF)) {
assert(HasFP && "There should be a frame pointer if stack is realigned.");
- uint64_t Val = -MaxAlign;
- MachineInstr *MI =
- BuildMI(MBB, MBBI, DL, TII.get(getANDriOpcode(Uses64BitFramePtr, Val)),
- StackPtr)
- .addReg(StackPtr)
- .addImm(Val)
- .setMIFlag(MachineInstr::FrameSetup);
-
- // The EFLAGS implicit def is dead.
- MI->getOperand(3).setIsDead();
+ BuildStackAlignAND(MBB, MBBI, DL, MaxAlign);
}
// If there is an SUB32ri of ESP immediately before this instruction, merge
// the two. This can be the case when tail call elimination is enabled and
// the callee has more arguments then the caller.
- NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
+ NumBytes -= mergeSPUpdates(MBB, MBBI, true);
// Adjust stack pointer: ESP -= numbytes.
// increments is necessary to ensure that the guard pages used by the OS
// virtual memory manager are allocated in correct sequence.
uint64_t AlignedNumBytes = NumBytes;
- if (IsWin64Prologue && RegInfo->needsStackRealignment(MF))
+ if (IsWin64Prologue && TRI->needsStackRealignment(MF))
AlignedNumBytes = RoundUpToAlignment(AlignedNumBytes, MaxAlign);
if (AlignedNumBytes >= StackProbeSize && UseStackProbe) {
// Check whether EAX is livein for this function.
MBB.insert(MBBI, MI);
}
} else if (NumBytes) {
- emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, Uses64BitFramePtr,
- UseLEA, TII, *RegInfo);
+ emitSPUpdate(MBB, MBBI, -(int64_t)NumBytes, /*InEpilogue=*/false);
}
if (NeedsWinCFI && NumBytes)
// Realign stack after we spilled callee-saved registers (so that we'll be
// able to calculate their offsets from the frame pointer).
// Win64 requires aligning the stack after the prologue.
- if (IsWin64Prologue && RegInfo->needsStackRealignment(MF)) {
+ if (IsWin64Prologue && TRI->needsStackRealignment(MF)) {
assert(HasFP && "There should be a frame pointer if stack is realigned.");
- uint64_t Val = -MaxAlign;
- MachineInstr *MI =
- BuildMI(MBB, MBBI, DL, TII.get(getANDriOpcode(Uses64BitFramePtr, Val)),
- StackPtr)
- .addReg(StackPtr)
- .addImm(Val)
- .setMIFlag(MachineInstr::FrameSetup);
-
- // The EFLAGS implicit def is dead.
- MI->getOperand(3).setIsDead();
+ BuildStackAlignAND(MBB, MBBI, DL, MaxAlign);
}
// 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)) {
+ if (TRI->hasBasePointer(MF)) {
// Update the base pointer with the current stack pointer.
unsigned Opc = Uses64BitFramePtr ? X86::MOV64rr : X86::MOV32rr;
BuildMI(MBB, MBBI, DL, TII.get(Opc), BasePtr)
.addReg(StackPtr)
.setMIFlag(MachineInstr::FrameSetup);
if (X86FI->getRestoreBasePointer()) {
- // Stash value of base pointer. Saving RSP instead of EBP shortens dependence chain.
+ // Stash value of base pointer. Saving RSP instead of EBP shortens
+ // dependence chain. Used by SjLj EH.
unsigned Opm = Uses64BitFramePtr ? X86::MOV64mr : X86::MOV32mr;
addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(Opm)),
FramePtr, true, X86FI->getRestoreBasePointerOffset())
.addReg(StackPtr)
.setMIFlag(MachineInstr::FrameSetup);
}
+
+ if (X86FI->getHasSEHFramePtrSave()) {
+ // Stash the value of the frame pointer relative to the base pointer for
+ // Win32 EH. This supports Win32 EH, which does the inverse of the above:
+ // it recovers the frame pointer from the base pointer rather than the
+ // other way around.
+ unsigned Opm = Uses64BitFramePtr ? X86::MOV64mr : X86::MOV32mr;
+ addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(Opm)), BasePtr, true,
+ getFrameIndexOffset(MF, X86FI->getSEHFramePtrSaveIndex()))
+ .addReg(FramePtr)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
}
if (((!HasFP && NumBytes) || PushedRegs) && NeedsDwarfCFI) {
if (!HasFP && NumBytes) {
// Define the current CFA rule to use the provided offset.
assert(StackSize);
- BuildCFI(MBB, MBBI, DL, TII, MCCFIInstruction::createDefCfaOffset(
- nullptr, -StackSize + stackGrowth));
+ BuildCFI(MBB, MBBI, DL, MCCFIInstruction::createDefCfaOffset(
+ nullptr, -StackSize + stackGrowth));
}
// Emit DWARF info specifying the offsets of the callee-saved registers.
return !MF.getTarget().getMCAsmInfo()->usesWindowsCFI() || hasFP(MF);
}
-/// Check whether or not the terminators of \p MBB needs to read EFLAGS.
-static bool terminatorsNeedFlagsAsInput(const MachineBasicBlock &MBB) {
- for (const MachineInstr &MI : MBB.terminators()) {
- bool BreakNext = false;
- for (const MachineOperand &MO : MI.operands()) {
- if (!MO.isReg())
- continue;
- unsigned Reg = MO.getReg();
- if (Reg != X86::EFLAGS)
- continue;
-
- // This terminator needs an eflag that is not defined
- // by a previous terminator.
- if (!MO.isDef())
- return true;
- BreakNext = true;
- }
- if (BreakNext)
- break;
- }
- return false;
-}
-
void X86FrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const X86RegisterInfo *RegInfo = STI.getRegisterInfo();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
MachineBasicBlock::iterator MBBI = MBB.getFirstTerminator();
DebugLoc DL;
if (MBBI != MBB.end())
DL = MBBI->getDebugLoc();
- bool Is64Bit = STI.is64Bit();
// standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
- const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
const bool Is64BitILP32 = STI.isTarget64BitILP32();
- unsigned SlotSize = RegInfo->getSlotSize();
- unsigned FramePtr = RegInfo->getFrameRegister(MF);
+ unsigned FramePtr = TRI->getFrameRegister(MF);
unsigned MachineFramePtr =
Is64BitILP32 ? getX86SubSuperRegister(FramePtr, MVT::i64, false)
: FramePtr;
- unsigned StackPtr = RegInfo->getStackRegister();
bool IsWin64Prologue = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
bool NeedsWinCFI =
IsWin64Prologue && MF.getFunction()->needsUnwindTableEntry();
- bool UseLEAForSP = canUseLEAForSPInEpilogue(MF);
- // If we can use LEA for SP but we shouldn't, check that none
- // of the terminators uses the eflags. Otherwise we will insert
- // a ADD that will redefine the eflags and break the condition.
- // Alternatively, we could move the ADD, but this may not be possible
- // and is an optimization anyway.
- if (UseLEAForSP && !MF.getSubtarget<X86Subtarget>().useLeaForSP())
- UseLEAForSP = terminatorsNeedFlagsAsInput(MBB);
- // If that assert breaks, that means we do not do the right thing
- // in canUseAsEpilogue.
- assert((UseLEAForSP || !terminatorsNeedFlagsAsInput(MBB)) &&
- "We shouldn't have allowed this insertion point");
// Get the number of bytes to allocate from the FrameInfo.
uint64_t StackSize = MFI->getStackSize();
// Callee-saved registers were pushed on stack before the stack was
// realigned.
- if (RegInfo->needsStackRealignment(MF) && !IsWin64Prologue)
+ if (TRI->needsStackRealignment(MF) && !IsWin64Prologue)
NumBytes = RoundUpToAlignment(FrameSize, MaxAlign);
// Pop EBP.
// If dynamic alloca is used, then reset esp to point to the last callee-saved
// slot before popping them off! Same applies for the case, when stack was
// realigned.
- if (RegInfo->needsStackRealignment(MF) || MFI->hasVarSizedObjects()) {
- if (RegInfo->needsStackRealignment(MF))
+ if (TRI->needsStackRealignment(MF) || MFI->hasVarSizedObjects()) {
+ if (TRI->needsStackRealignment(MF))
MBBI = FirstCSPop;
unsigned SEHFrameOffset = calculateSetFPREG(SEHStackAllocAmt);
uint64_t LEAAmount =
}
} else if (NumBytes) {
// Adjust stack pointer back: ESP += numbytes.
- emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, Uses64BitFramePtr,
- UseLEAForSP, TII, *RegInfo);
+ emitSPUpdate(MBB, MBBI, NumBytes, /*InEpilogue=*/true);
--MBBI;
}
MBBI = MBB.getFirstTerminator();
// Check for possible merge with preceding ADD instruction.
- Offset += mergeSPUpdates(MBB, MBBI, StackPtr, true);
- emitSPUpdate(MBB, MBBI, StackPtr, Offset, Is64Bit, Uses64BitFramePtr,
- UseLEAForSP, TII, *RegInfo);
+ Offset += mergeSPUpdates(MBB, MBBI, true);
+ emitSPUpdate(MBB, MBBI, Offset, /*InEpilogue=*/true);
}
}
int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
int FI) const {
- const X86RegisterInfo *RegInfo =
- MF.getSubtarget<X86Subtarget>().getRegisterInfo();
const MachineFrameInfo *MFI = MF.getFrameInfo();
// Offset will hold the offset from the stack pointer at function entry to the
// object.
const X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
unsigned CSSize = X86FI->getCalleeSavedFrameSize();
uint64_t StackSize = MFI->getStackSize();
- unsigned SlotSize = RegInfo->getSlotSize();
bool HasFP = hasFP(MF);
bool IsWin64Prologue = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
int64_t FPDelta = 0;
}
- if (RegInfo->hasBasePointer(MF)) {
+ if (TRI->hasBasePointer(MF)) {
assert(HasFP && "VLAs and dynamic stack realign, but no FP?!");
if (FI < 0) {
// Skip the saved EBP.
assert((-(Offset + StackSize)) % MFI->getObjectAlignment(FI) == 0);
return Offset + StackSize;
}
- } else if (RegInfo->needsStackRealignment(MF)) {
+ } else if (TRI->needsStackRealignment(MF)) {
if (FI < 0) {
// Skip the saved EBP.
return Offset + SlotSize + FPDelta;
int X86FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
unsigned &FrameReg) const {
- const X86RegisterInfo *RegInfo =
- MF.getSubtarget<X86Subtarget>().getRegisterInfo();
// We can't calculate offset from frame pointer if the stack is realigned,
// so enforce usage of stack/base pointer. The base pointer is used when we
// have dynamic allocas in addition to dynamic realignment.
- if (RegInfo->hasBasePointer(MF))
- FrameReg = RegInfo->getBaseRegister();
- else if (RegInfo->needsStackRealignment(MF))
- FrameReg = RegInfo->getStackRegister();
+ if (TRI->hasBasePointer(MF))
+ FrameReg = TRI->getBaseRegister();
+ else if (TRI->needsStackRealignment(MF))
+ FrameReg = TRI->getStackRegister();
else
- FrameReg = RegInfo->getFrameRegister(MF);
+ FrameReg = TRI->getFrameRegister(MF);
return getFrameIndexOffset(MF, FI);
}
const uint64_t StackSize = MFI->getStackSize();
{
#ifndef NDEBUG
- const X86RegisterInfo *RegInfo =
- MF.getSubtarget<X86Subtarget>().getRegisterInfo();
// Note: LLVM arranges the stack as:
// Args > Saved RetPC (<--FP) > CSRs > dynamic alignment (<--BP)
// > "Stack Slots" (<--SP)
// frame). As a result, THE RESULT OF THIS CALL IS MEANINGLESS FOR CSRs
// AND FixedObjects IFF needsStackRealignment or hasVarSizedObject.
- assert(!RegInfo->hasBasePointer(MF) && "we don't handle this case");
+ assert(!TRI->hasBasePointer(MF) && "we don't handle this case");
// We don't handle tail calls, and shouldn't be seeing them
// either.
int X86FrameLowering::getFrameIndexReferenceFromSP(const MachineFunction &MF,
int FI,
unsigned &FrameReg) const {
- const X86RegisterInfo *RegInfo =
- MF.getSubtarget<X86Subtarget>().getRegisterInfo();
- assert(!RegInfo->hasBasePointer(MF) && "we don't handle this case");
+ assert(!TRI->hasBasePointer(MF) && "we don't handle this case");
- FrameReg = RegInfo->getStackRegister();
+ FrameReg = TRI->getStackRegister();
return getFrameIndexOffsetFromSP(MF, FI);
}
MachineFunction &MF, const TargetRegisterInfo *TRI,
std::vector<CalleeSavedInfo> &CSI) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
- const X86RegisterInfo *RegInfo =
- MF.getSubtarget<X86Subtarget>().getRegisterInfo();
- unsigned SlotSize = RegInfo->getSlotSize();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
unsigned CalleeSavedFrameSize = 0;
// Since emitPrologue and emitEpilogue will handle spilling and restoring of
// the frame register, we can delete it from CSI list and not have to worry
// about avoiding it later.
- unsigned FPReg = RegInfo->getFrameRegister(MF);
+ unsigned FPReg = TRI->getFrameRegister(MF);
for (unsigned i = 0; i < CSI.size(); ++i) {
if (TRI->regsOverlap(CSI[i].getReg(),FPReg)) {
CSI.erase(CSI.begin() + i);
if (X86::GR64RegClass.contains(Reg) || X86::GR32RegClass.contains(Reg))
continue;
- const TargetRegisterClass *RC = RegInfo->getMinimalPhysRegClass(Reg);
+ const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
// ensure alignment
SpillSlotOffset -= std::abs(SpillSlotOffset) % RC->getAlignment();
// spill into slot
const TargetRegisterInfo *TRI) const {
DebugLoc DL = MBB.findDebugLoc(MI);
- MachineFunction &MF = *MBB.getParent();
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
-
// Push GPRs. It increases frame size.
unsigned Opc = STI.is64Bit() ? X86::PUSH64r : X86::PUSH32r;
for (unsigned i = CSI.size(); i != 0; --i) {
DebugLoc DL = MBB.findDebugLoc(MI);
- MachineFunction &MF = *MBB.getParent();
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
-
// Reload XMMs from stack frame.
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
return true;
}
-void
-X86FrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS) const {
+void X86FrameLowering::determineCalleeSaves(MachineFunction &MF,
+ BitVector &SavedRegs,
+ RegScavenger *RS) const {
+ TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS);
+
MachineFrameInfo *MFI = MF.getFrameInfo();
- const X86RegisterInfo *RegInfo =
- MF.getSubtarget<X86Subtarget>().getRegisterInfo();
- unsigned SlotSize = RegInfo->getSlotSize();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
int64_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
}
// Spill the BasePtr if it's used.
- if (RegInfo->hasBasePointer(MF))
- MF.getRegInfo().setPhysRegUsed(RegInfo->getBaseRegister());
+ if (TRI->hasBasePointer(MF))
+ SavedRegs.set(TRI->getBaseRegister());
}
static bool
void X86FrameLowering::adjustForSegmentedStacks(
MachineFunction &MF, MachineBasicBlock &PrologueMBB) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
uint64_t StackSize;
- bool Is64Bit = STI.is64Bit();
- const bool IsLP64 = STI.isTarget64BitLP64();
unsigned TlsReg, TlsOffset;
DebugLoc DL;
.addImm(StackSize);
BuildMI(allocMBB, DL, TII.get(MOVri), Reg11)
.addImm(X86FI->getArgumentStackSize());
- MF.getRegInfo().setPhysRegUsed(Reg10);
- MF.getRegInfo().setPhysRegUsed(Reg11);
} else {
BuildMI(allocMBB, DL, TII.get(X86::PUSHi32))
.addImm(X86FI->getArgumentStackSize());
/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
void X86FrameLowering::adjustForHiPEPrologue(
MachineFunction &MF, MachineBasicBlock &PrologueMBB) const {
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
MachineFrameInfo *MFI = MF.getFrameInfo();
- const unsigned SlotSize = STI.getRegisterInfo()->getSlotSize();
- const bool Is64Bit = STI.is64Bit();
- const bool IsLP64 = STI.isTarget64BitLP64();
DebugLoc DL;
// HiPE-specific values
const unsigned HipeLeafWords = 24;
void X86FrameLowering::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
- const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
- const TargetInstrInfo &TII = *STI.getInstrInfo();
- const X86RegisterInfo &RegInfo = *STI.getRegisterInfo();
- unsigned StackPtr = RegInfo.getStackRegister();
bool reserveCallFrame = hasReservedCallFrame(MF);
unsigned Opcode = I->getOpcode();
bool isDestroy = Opcode == TII.getCallFrameDestroyOpcode();
- bool IsLP64 = STI.isTarget64BitLP64();
DebugLoc DL = I->getDebugLoc();
uint64_t Amount = !reserveCallFrame ? I->getOperand(0).getImm() : 0;
uint64_t InternalAmt = (isDestroy || Amount) ? I->getOperand(1).getImm() : 0;
unsigned StackAlign = getStackAlignment();
Amount = RoundUpToAlignment(Amount, StackAlign);
- MachineInstr *New = nullptr;
-
// Factor out the amount that gets handled inside the sequence
// (Pushes of argument for frame setup, callee pops for frame destroy)
Amount -= InternalAmt;
if (Amount) {
- if (Opcode == TII.getCallFrameSetupOpcode()) {
- New = BuildMI(MF, DL, TII.get(getSUBriOpcode(IsLP64, Amount)), StackPtr)
- .addReg(StackPtr).addImm(Amount);
- } else {
- assert(Opcode == TII.getCallFrameDestroyOpcode());
-
- unsigned Opc = getADDriOpcode(IsLP64, Amount);
- New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
- .addReg(StackPtr).addImm(Amount);
- }
+ // Add Amount to SP to destroy a frame, and subtract to setup.
+ int Offset = isDestroy ? Amount : -Amount;
+ BuildStackAdjustment(MBB, I, DL, Offset, /*InEpilogue=*/false);
}
-
- if (New) {
- // The EFLAGS implicit def is dead.
- New->getOperand(3).setIsDead();
-
- // Replace the pseudo instruction with a new instruction.
- MBB.insert(I, New);
- }
-
return;
}
- if (Opcode == TII.getCallFrameDestroyOpcode() && InternalAmt) {
+ if (isDestroy && InternalAmt) {
// If we are performing frame pointer elimination and if the callee pops
// something off the stack pointer, add it back. We do this until we have
// more advanced stack pointer tracking ability.
- unsigned Opc = getSUBriOpcode(IsLP64, InternalAmt);
- MachineInstr *New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
- .addReg(StackPtr).addImm(InternalAmt);
-
- // The EFLAGS implicit def is dead.
- New->getOperand(3).setIsDead();
-
// We are not tracking the stack pointer adjustment by the callee, so make
// sure we restore the stack pointer immediately after the call, there may
// be spill code inserted between the CALL and ADJCALLSTACKUP instructions.
MachineBasicBlock::iterator B = MBB.begin();
while (I != B && !std::prev(I)->isCall())
--I;
- MBB.insert(I, New);
+ BuildStackAdjustment(MBB, I, DL, -InternalAmt, /*InEpilogue=*/false);
}
}