#include "llvm/MC/MCSymbol.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/Debug.h"
+#include <cstdlib>
using namespace llvm;
extern cl::opt<bool> ForceStackAlign;
bool X86FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
- return !MF.getFrameInfo()->hasVarSizedObjects();
+ return !MF.getFrameInfo()->hasVarSizedObjects() &&
+ !MF.getInfo<X86MachineFunctionInfo>()->getHasPushSequences();
+}
+
+/// canSimplifyCallFramePseudos - If there is a reserved call frame, the
+/// call frame pseudos can be simplified. Having a FP, as in the default
+/// implementation, is not sufficient here since we can't always use it.
+/// 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);
+}
+
+// needsFrameIndexResolution - Do we need to perform FI resolution for
+// this function. Normally, this is required only when the function
+// has any stack objects. However, FI resolution actually has another job,
+// not apparent from the title - it resolves callframesetup/destroy
+// that were not simplified earlier.
+// So, this is required for x86 functions that have push sequences even
+// when there are no stack objects.
+bool
+X86FrameLowering::needsFrameIndexResolution(const MachineFunction &MF) const {
+ return MF.getFrameInfo()->hasStackObjects() ||
+ MF.getInfo<X86MachineFunctionInfo>()->getHasPushSequences();
}
/// hasFP - Return true if the specified function should have a dedicated frame
bool X86FrameLowering::hasFP(const MachineFunction &MF) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
const MachineModuleInfo &MMI = MF.getMMI();
- const TargetRegisterInfo *RegInfo = TM.getRegisterInfo();
+ const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
return (MF.getTarget().Options.DisableFramePointerElim(MF) ||
RegInfo->needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
- MFI->isFrameAddressTaken() || MF.hasMSInlineAsm() ||
+ MFI->isFrameAddressTaken() || MFI->hasInlineAsmWithSPAdjust() ||
MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
- MMI.callsUnwindInit() || MMI.callsEHReturn());
+ MMI.callsUnwindInit() || MMI.callsEHReturn() ||
+ MFI->hasStackMap() || MFI->hasPatchPoint());
}
static unsigned getSUBriOpcode(unsigned IsLP64, int64_t Imm) {
}
}
+static unsigned getSUBrrOpcode(unsigned isLP64) {
+ return isLP64 ? X86::SUB64rr : X86::SUB32rr;
+}
+
+static unsigned getADDrrOpcode(unsigned isLP64) {
+ return isLP64 ? X86::ADD64rr : X86::ADD32rr;
+}
+
+static unsigned getANDriOpcode(bool IsLP64, int64_t Imm) {
+ if (IsLP64) {
+ if (isInt<8>(Imm))
+ return X86::AND64ri8;
+ return X86::AND64ri32;
+ }
+ if (isInt<8>(Imm))
+ return X86::AND32ri8;
+ return X86::AND32ri;
+}
+
static unsigned getLEArOpcode(unsigned IsLP64) {
return IsLP64 ? X86::LEA64r : X86::LEA32r;
}
unsigned Opc = MBBI->getOpcode();
switch (Opc) {
default: return 0;
- case X86::RET:
- case X86::RETI:
+ case X86::RETL:
+ case X86::RETQ:
+ case X86::RETIL:
+ case X86::RETIQ:
case X86::TCRETURNdi:
case X86::TCRETURNri:
case X86::TCRETURNmi:
return 0;
}
+static bool isEAXLiveIn(MachineFunction &MF) {
+ for (MachineRegisterInfo::livein_iterator II = MF.getRegInfo().livein_begin(),
+ EE = MF.getRegInfo().livein_end(); II != EE; ++II) {
+ unsigned Reg = II->first;
+
+ if (Reg == X86::RAX || Reg == X86::EAX || Reg == X86::AX ||
+ Reg == X86::AH || Reg == X86::AL)
+ return true;
+ }
+
+ return false;
+}
/// emitSPUpdate - Emit a series of instructions to increment / decrement the
/// stack pointer by a constant value.
static
void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
unsigned StackPtr, int64_t NumBytes,
- bool Is64Bit, bool IsLP64, bool UseLEA,
+ bool Is64BitTarget, bool Is64BitStackPtr, bool UseLEA,
const TargetInstrInfo &TII, const TargetRegisterInfo &TRI) {
bool isSub = NumBytes < 0;
uint64_t Offset = isSub ? -NumBytes : NumBytes;
unsigned Opc;
if (UseLEA)
- Opc = getLEArOpcode(IsLP64);
+ Opc = getLEArOpcode(Is64BitStackPtr);
else
Opc = isSub
- ? getSUBriOpcode(IsLP64, Offset)
- : getADDriOpcode(IsLP64, Offset);
+ ? getSUBriOpcode(Is64BitStackPtr, Offset)
+ : getADDriOpcode(Is64BitStackPtr, Offset);
uint64_t Chunk = (1LL << 31) - 1;
DebugLoc DL = MBB.findDebugLoc(MBBI);
while (Offset) {
- uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset;
- if (ThisVal == (Is64Bit ? 8 : 4)) {
+ if (Offset > Chunk) {
+ // Rather than emit a long series of instructions for large offsets,
+ // load the offset into a register and do one sub/add
+ unsigned Reg = 0;
+
+ if (isSub && !isEAXLiveIn(*MBB.getParent()))
+ Reg = (unsigned)(Is64BitTarget ? X86::RAX : X86::EAX);
+ else
+ Reg = findDeadCallerSavedReg(MBB, MBBI, TRI, Is64BitTarget);
+
+ if (Reg) {
+ Opc = Is64BitTarget ? X86::MOV64ri : X86::MOV32ri;
+ BuildMI(MBB, MBBI, DL, TII.get(Opc), Reg)
+ .addImm(Offset);
+ Opc = isSub
+ ? getSUBrrOpcode(Is64BitTarget)
+ : getADDrrOpcode(Is64BitTarget);
+ MachineInstr *MI = BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
+ .addReg(StackPtr)
+ .addReg(Reg);
+ MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
+ Offset = 0;
+ continue;
+ }
+ }
+
+ uint64_t ThisVal = std::min(Offset, Chunk);
+ if (ThisVal == (Is64BitTarget ? 8 : 4)) {
// Use push / pop instead.
unsigned Reg = isSub
- ? (unsigned)(Is64Bit ? X86::RAX : X86::EAX)
- : findDeadCallerSavedReg(MBB, MBBI, TRI, Is64Bit);
+ ? (unsigned)(Is64BitTarget ? X86::RAX : X86::EAX)
+ : findDeadCallerSavedReg(MBB, MBBI, TRI, Is64BitTarget);
if (Reg) {
Opc = isSub
- ? (Is64Bit ? X86::PUSH64r : X86::PUSH32r)
- : (Is64Bit ? X86::POP64r : X86::POP32r);
+ ? (Is64BitTarget ? X86::PUSH64r : X86::PUSH32r)
+ : (Is64BitTarget ? X86::POP64r : X86::POP32r);
MachineInstr *MI = BuildMI(MBB, MBBI, DL, TII.get(Opc))
.addReg(Reg, getDefRegState(!isSub) | getUndefRegState(isSub));
if (isSub)
}
}
- MachineInstr *MI = NULL;
+ MachineInstr *MI = nullptr;
if (UseLEA) {
MI = addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr),
/// mergeSPUpdatesUp - Merge two stack-manipulating instructions upper iterator.
static
void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr, uint64_t *NumBytes = NULL) {
+ unsigned StackPtr, uint64_t *NumBytes = nullptr) {
if (MBBI == MBB.begin()) return;
- MachineBasicBlock::iterator PI = prior(MBBI);
+ MachineBasicBlock::iterator PI = std::prev(MBBI);
unsigned Opc = PI->getOpcode();
if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
Opc == X86::ADD32ri || Opc == X86::ADD32ri8 ||
}
}
-/// mergeSPUpdatesDown - Merge two stack-manipulating instructions lower iterator.
-static
-void mergeSPUpdatesDown(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr, uint64_t *NumBytes = NULL) {
- // FIXME: THIS ISN'T RUN!!!
- return;
-
- if (MBBI == MBB.end()) return;
-
- MachineBasicBlock::iterator NI = llvm::next(MBBI);
- if (NI == MBB.end()) return;
-
- unsigned Opc = NI->getOpcode();
- if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
- Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
- NI->getOperand(0).getReg() == StackPtr) {
- if (NumBytes)
- *NumBytes -= NI->getOperand(2).getImm();
- MBB.erase(NI);
- MBBI = NI;
- } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
- Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
- NI->getOperand(0).getReg() == StackPtr) {
- if (NumBytes)
- *NumBytes += NI->getOperand(2).getImm();
- MBB.erase(NI);
- MBBI = NI;
- }
-}
-
/// mergeSPUpdates - Checks the instruction before/after the passed
-/// instruction. If it is an ADD/SUB/LEA instruction it is deleted argument and the
-/// stack adjustment is returned as a positive value for ADD/LEA and a negative for
-/// SUB.
+/// instruction. If it is an ADD/SUB/LEA instruction it is deleted argument and
+/// the stack adjustment is returned as a positive value for ADD/LEA and a
+/// negative for SUB.
static int mergeSPUpdates(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr,
- bool doMergeWithPrevious) {
+ MachineBasicBlock::iterator &MBBI, unsigned StackPtr,
+ bool doMergeWithPrevious) {
if ((doMergeWithPrevious && MBBI == MBB.begin()) ||
(!doMergeWithPrevious && MBBI == MBB.end()))
return 0;
- MachineBasicBlock::iterator PI = doMergeWithPrevious ? prior(MBBI) : MBBI;
- MachineBasicBlock::iterator NI = doMergeWithPrevious ? 0 : llvm::next(MBBI);
+ MachineBasicBlock::iterator PI = doMergeWithPrevious ? std::prev(MBBI) : MBBI;
+ MachineBasicBlock::iterator NI = doMergeWithPrevious ? nullptr
+ : std::next(MBBI);
unsigned Opc = PI->getOpcode();
int Offset = 0;
return Offset;
}
-static bool isEAXLiveIn(MachineFunction &MF) {
- for (MachineRegisterInfo::livein_iterator II = MF.getRegInfo().livein_begin(),
- EE = MF.getRegInfo().livein_end(); II != EE; ++II) {
- unsigned Reg = II->first;
-
- if (Reg == X86::EAX || Reg == X86::AX ||
- Reg == X86::AH || Reg == X86::AL)
- return true;
- }
-
- return false;
-}
-
-void X86FrameLowering::emitCalleeSavedFrameMoves(MachineFunction &MF,
- MCSymbol *Label,
- unsigned FramePtr) const {
+void
+X86FrameLowering::emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator MBBI,
+ DebugLoc DL) const {
+ MachineFunction &MF = *MBB.getParent();
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();
if (CSI.empty()) return;
- const X86RegisterInfo *RegInfo = TM.getRegisterInfo();
- bool HasFP = hasFP(MF);
-
- // Calculate amount of bytes used for return address storing.
- int stackGrowth = -RegInfo->getSlotSize();
-
- // FIXME: This is dirty hack. The code itself is pretty mess right now.
- // It should be rewritten from scratch and generalized sometimes.
-
- // Determine maximum offset (minimum due to stack growth).
- int64_t MaxOffset = 0;
- for (std::vector<CalleeSavedInfo>::const_iterator
- I = CSI.begin(), E = CSI.end(); I != E; ++I)
- MaxOffset = std::min(MaxOffset,
- MFI->getObjectOffset(I->getFrameIdx()));
-
// Calculate offsets.
- int64_t saveAreaOffset = (HasFP ? 3 : 2) * stackGrowth;
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();
- Offset = MaxOffset - Offset + saveAreaOffset;
-
- // Don't output a new machine move if we're re-saving the frame
- // pointer. This happens when the PrologEpilogInserter has inserted an extra
- // "PUSH" of the frame pointer -- the "emitPrologue" method automatically
- // generates one when frame pointers are used. If we generate a "machine
- // move" for this extra "PUSH", the linker will lose track of the fact that
- // the frame pointer should have the value of the first "PUSH" when it's
- // trying to unwind.
- //
- // FIXME: This looks inelegant. It's possibly correct, but it's covering up
- // another bug. I.e., one where we generate a prolog like this:
- //
- // pushl %ebp
- // movl %esp, %ebp
- // pushl %ebp
- // pushl %esi
- // ...
- //
- // The immediate re-push of EBP is unnecessary. At the least, it's an
- // optimization bug. EBP can be used as a scratch register in certain
- // cases, but probably not when we have a frame pointer.
- if (HasFP && FramePtr == Reg)
- continue;
- MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
- MachineLocation CSSrc(Reg);
- MMI.addFrameMove(Label, CSDst, CSSrc);
+ unsigned DwarfReg = MRI->getDwarfRegNum(Reg, true);
+ unsigned CFIIndex =
+ MMI.addFrameInst(MCCFIInstruction::createOffset(nullptr, DwarfReg,
+ Offset));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
}
-/// getCompactUnwindRegNum - Get the compact unwind number for a given
-/// register. The number corresponds to the enum lists in
-/// compact_unwind_encoding.h.
-static int getCompactUnwindRegNum(unsigned Reg, bool is64Bit) {
- static const uint16_t CU32BitRegs[] = {
- X86::EBX, X86::ECX, X86::EDX, X86::EDI, X86::ESI, X86::EBP, 0
- };
- static const uint16_t CU64BitRegs[] = {
- X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
- };
- const uint16_t *CURegs = is64Bit ? CU64BitRegs : CU32BitRegs;
- for (int Idx = 1; *CURegs; ++CURegs, ++Idx)
- if (*CURegs == Reg)
- return Idx;
-
- return -1;
-}
-
-// Number of registers that can be saved in a compact unwind encoding.
-#define CU_NUM_SAVED_REGS 6
-
-/// encodeCompactUnwindRegistersWithoutFrame - Create the permutation encoding
-/// used with frameless stacks. It is passed the number of registers to be saved
-/// and an array of the registers saved.
-static uint32_t
-encodeCompactUnwindRegistersWithoutFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
- unsigned RegCount, bool Is64Bit) {
- // The saved registers are numbered from 1 to 6. In order to encode the order
- // in which they were saved, we re-number them according to their place in the
- // register order. The re-numbering is relative to the last re-numbered
- // register. E.g., if we have registers {6, 2, 4, 5} saved in that order:
- //
- // Orig Re-Num
- // ---- ------
- // 6 6
- // 2 2
- // 4 3
- // 5 3
- //
- for (unsigned i = 0; i != CU_NUM_SAVED_REGS; ++i) {
- int CUReg = getCompactUnwindRegNum(SavedRegs[i], Is64Bit);
- if (CUReg == -1) return ~0U;
- SavedRegs[i] = CUReg;
- }
-
- // Reverse the list.
- std::swap(SavedRegs[0], SavedRegs[5]);
- std::swap(SavedRegs[1], SavedRegs[4]);
- std::swap(SavedRegs[2], SavedRegs[3]);
-
- uint32_t RenumRegs[CU_NUM_SAVED_REGS];
- for (unsigned i = CU_NUM_SAVED_REGS - RegCount; i < CU_NUM_SAVED_REGS; ++i) {
- unsigned Countless = 0;
- for (unsigned j = CU_NUM_SAVED_REGS - RegCount; j < i; ++j)
- if (SavedRegs[j] < SavedRegs[i])
- ++Countless;
-
- RenumRegs[i] = SavedRegs[i] - Countless - 1;
- }
-
- // Take the renumbered values and encode them into a 10-bit number.
- uint32_t permutationEncoding = 0;
- switch (RegCount) {
- case 6:
- permutationEncoding |= 120 * RenumRegs[0] + 24 * RenumRegs[1]
- + 6 * RenumRegs[2] + 2 * RenumRegs[3]
- + RenumRegs[4];
- break;
- case 5:
- permutationEncoding |= 120 * RenumRegs[1] + 24 * RenumRegs[2]
- + 6 * RenumRegs[3] + 2 * RenumRegs[4]
- + RenumRegs[5];
- break;
- case 4:
- permutationEncoding |= 60 * RenumRegs[2] + 12 * RenumRegs[3]
- + 3 * RenumRegs[4] + RenumRegs[5];
- break;
- case 3:
- permutationEncoding |= 20 * RenumRegs[3] + 4 * RenumRegs[4]
- + RenumRegs[5];
- break;
- case 2:
- permutationEncoding |= 5 * RenumRegs[4] + RenumRegs[5];
- break;
- case 1:
- permutationEncoding |= RenumRegs[5];
- break;
- }
-
- assert((permutationEncoding & 0x3FF) == permutationEncoding &&
- "Invalid compact register encoding!");
- return permutationEncoding;
-}
+/// usesTheStack - This function checks if any of the users of EFLAGS
+/// copies the EFLAGS. We know that the code that lowers COPY of EFLAGS has
+/// to use the stack, and if we don't adjust the stack we clobber the first
+/// frame index.
+/// See X86InstrInfo::copyPhysReg.
+static bool usesTheStack(const MachineFunction &MF) {
+ const MachineRegisterInfo &MRI = MF.getRegInfo();
-/// encodeCompactUnwindRegistersWithFrame - Return the registers encoded for a
-/// compact encoding with a frame pointer.
-static uint32_t
-encodeCompactUnwindRegistersWithFrame(unsigned SavedRegs[CU_NUM_SAVED_REGS],
- bool Is64Bit) {
- // Encode the registers in the order they were saved, 3-bits per register. The
- // registers are numbered from 1 to CU_NUM_SAVED_REGS.
- uint32_t RegEnc = 0;
- for (int I = CU_NUM_SAVED_REGS - 1, Idx = 0; I != -1; --I) {
- unsigned Reg = SavedRegs[I];
- if (Reg == 0) continue;
-
- int CURegNum = getCompactUnwindRegNum(Reg, Is64Bit);
- if (CURegNum == -1) return ~0U;
-
- // Encode the 3-bit register number in order, skipping over 3-bits for each
- // register.
- RegEnc |= (CURegNum & 0x7) << (Idx++ * 3);
- }
+ for (MachineRegisterInfo::reg_instr_iterator
+ ri = MRI.reg_instr_begin(X86::EFLAGS), re = MRI.reg_instr_end();
+ ri != re; ++ri)
+ if (ri->isCopy())
+ return true;
- assert((RegEnc & 0x3FFFF) == RegEnc && "Invalid compact register encoding!");
- return RegEnc;
+ return false;
}
-uint32_t X86FrameLowering::getCompactUnwindEncoding(MachineFunction &MF) const {
- const X86RegisterInfo *RegInfo = TM.getRegisterInfo();
- unsigned FramePtr = RegInfo->getFrameRegister(MF);
- unsigned StackPtr = RegInfo->getStackRegister();
-
+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();
- bool HasFP = hasFP(MF);
-
- unsigned SavedRegs[CU_NUM_SAVED_REGS] = { 0, 0, 0, 0, 0, 0 };
- unsigned SavedRegIdx = 0;
-
- unsigned OffsetSize = (Is64Bit ? 8 : 4);
-
- unsigned PushInstr = (Is64Bit ? X86::PUSH64r : X86::PUSH32r);
- unsigned PushInstrSize = 1;
- unsigned MoveInstr = (Is64Bit ? X86::MOV64rr : X86::MOV32rr);
- unsigned MoveInstrSize = (Is64Bit ? 3 : 2);
- unsigned SubtractInstrIdx = (Is64Bit ? 3 : 2);
-
- unsigned StackDivide = (Is64Bit ? 8 : 4);
-
- unsigned InstrOffset = 0;
- unsigned StackAdjust = 0;
- unsigned StackSize = 0;
-
- MachineBasicBlock &MBB = MF.front(); // Prologue is in entry BB.
- bool ExpectEnd = false;
- for (MachineBasicBlock::iterator
- MBBI = MBB.begin(), MBBE = MBB.end(); MBBI != MBBE; ++MBBI) {
- MachineInstr &MI = *MBBI;
- unsigned Opc = MI.getOpcode();
- if (Opc == X86::PROLOG_LABEL) continue;
- if (!MI.getFlag(MachineInstr::FrameSetup)) break;
+ bool IsLargeCodeModel = MF.getTarget().getCodeModel() == CodeModel::Large;
- // We don't exect any more prolog instructions.
- if (ExpectEnd) return CU::UNWIND_MODE_DWARF;
-
- if (Opc == PushInstr) {
- // If there are too many saved registers, we cannot use compact encoding.
- if (SavedRegIdx >= CU_NUM_SAVED_REGS) return CU::UNWIND_MODE_DWARF;
-
- unsigned Reg = MI.getOperand(0).getReg();
- if (Reg == (Is64Bit ? X86::RAX : X86::EAX)) {
- ExpectEnd = true;
- continue;
- }
-
- SavedRegs[SavedRegIdx++] = MI.getOperand(0).getReg();
- StackAdjust += OffsetSize;
- InstrOffset += PushInstrSize;
- } else if (Opc == MoveInstr) {
- unsigned SrcReg = MI.getOperand(1).getReg();
- unsigned DstReg = MI.getOperand(0).getReg();
-
- if (DstReg != FramePtr || SrcReg != StackPtr)
- return CU::UNWIND_MODE_DWARF;
-
- StackAdjust = 0;
- memset(SavedRegs, 0, sizeof(SavedRegs));
- SavedRegIdx = 0;
- InstrOffset += MoveInstrSize;
- } else if (Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
- Opc == X86::SUB32ri || Opc == X86::SUB32ri8) {
- if (StackSize)
- // We already have a stack size.
- return CU::UNWIND_MODE_DWARF;
-
- if (!MI.getOperand(0).isReg() ||
- MI.getOperand(0).getReg() != MI.getOperand(1).getReg() ||
- MI.getOperand(0).getReg() != StackPtr || !MI.getOperand(2).isImm())
- // We need this to be a stack adjustment pointer. Something like:
- //
- // %RSP<def> = SUB64ri8 %RSP, 48
- return CU::UNWIND_MODE_DWARF;
-
- StackSize = MI.getOperand(2).getImm() / StackDivide;
- SubtractInstrIdx += InstrOffset;
- ExpectEnd = true;
- }
- }
-
- // Encode that we are using EBP/RBP as the frame pointer.
- uint32_t CompactUnwindEncoding = 0;
- StackAdjust /= StackDivide;
- if (HasFP) {
- if ((StackAdjust & 0xFF) != StackAdjust)
- // Offset was too big for compact encoding.
- return CU::UNWIND_MODE_DWARF;
-
- // Get the encoding of the saved registers when we have a frame pointer.
- uint32_t RegEnc = encodeCompactUnwindRegistersWithFrame(SavedRegs, Is64Bit);
- if (RegEnc == ~0U) return CU::UNWIND_MODE_DWARF;
+ unsigned CallOp;
+ if (Is64Bit)
+ CallOp = IsLargeCodeModel ? X86::CALL64r : X86::CALL64pcrel32;
+ else
+ CallOp = X86::CALLpcrel32;
- CompactUnwindEncoding |= CU::UNWIND_MODE_BP_FRAME;
- CompactUnwindEncoding |= (StackAdjust & 0xFF) << 16;
- CompactUnwindEncoding |= RegEnc & CU::UNWIND_BP_FRAME_REGISTERS;
- } else {
- ++StackAdjust;
- uint32_t TotalStackSize = StackAdjust + StackSize;
- if ((TotalStackSize & 0xFF) == TotalStackSize) {
- // Frameless stack with a small stack size.
- CompactUnwindEncoding |= CU::UNWIND_MODE_STACK_IMMD;
-
- // Encode the stack size.
- CompactUnwindEncoding |= (TotalStackSize & 0xFF) << 16;
+ const char *Symbol;
+ if (Is64Bit) {
+ if (STI.isTargetCygMing()) {
+ Symbol = "___chkstk_ms";
} else {
- if ((StackAdjust & 0x7) != StackAdjust)
- // The extra stack adjustments are too big for us to handle.
- return CU::UNWIND_MODE_DWARF;
-
- // Frameless stack with an offset too large for us to encode compactly.
- CompactUnwindEncoding |= CU::UNWIND_MODE_STACK_IND;
-
- // Encode the offset to the nnnnnn value in the 'subl $nnnnnn, ESP'
- // instruction.
- CompactUnwindEncoding |= (SubtractInstrIdx & 0xFF) << 16;
-
- // Encode any extra stack stack adjustments (done via push instructions).
- CompactUnwindEncoding |= (StackAdjust & 0x7) << 13;
+ Symbol = "__chkstk";
}
+ } else if (STI.isTargetCygMing())
+ Symbol = "_alloca";
+ else
+ Symbol = "_chkstk";
+
+ MachineInstrBuilder CI;
+
+ // All current stack probes take AX and SP as input, clobber flags, and
+ // preserve all registers. x86_64 probes leave RSP unmodified.
+ if (Is64Bit && MF.getTarget().getCodeModel() == CodeModel::Large) {
+ // For the large code model, we have to call through a register. Use R11,
+ // as it is scratch in all supported calling conventions.
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri), X86::R11)
+ .addExternalSymbol(Symbol);
+ CI = BuildMI(MBB, MBBI, DL, TII.get(CallOp)).addReg(X86::R11);
+ } else {
+ CI = BuildMI(MBB, MBBI, DL, TII.get(CallOp)).addExternalSymbol(Symbol);
+ }
- // Encode the number of registers saved.
- CompactUnwindEncoding |= (SavedRegIdx & 0x7) << 10;
-
- // Get the encoding of the saved registers when we don't have a frame
- // pointer.
- uint32_t RegEnc =
- encodeCompactUnwindRegistersWithoutFrame(SavedRegs, SavedRegIdx,
- Is64Bit);
- if (RegEnc == ~0U) return CU::UNWIND_MODE_DWARF;
+ unsigned AX = Is64Bit ? X86::RAX : X86::EAX;
+ unsigned SP = Is64Bit ? X86::RSP : X86::ESP;
+ CI.addReg(AX, RegState::Implicit)
+ .addReg(SP, RegState::Implicit)
+ .addReg(AX, RegState::Define | RegState::Implicit)
+ .addReg(SP, RegState::Define | RegState::Implicit)
+ .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
- // Encode the register encoding.
- CompactUnwindEncoding |=
- RegEnc & CU::UNWIND_FRAMELESS_STACK_REG_PERMUTATION;
+ if (Is64Bit) {
+ // MSVC x64's __chkstk and cygwin/mingw's ___chkstk_ms do not adjust %rsp
+ // themselves. It also does not clobber %rax so we can reuse it when
+ // adjusting %rsp.
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SUB64rr), X86::RSP)
+ .addReg(X86::RSP)
+ .addReg(X86::RAX);
}
-
- return CompactUnwindEncoding;
}
-/// usesTheStack - This function checks if any of the users of EFLAGS
-/// copies the EFLAGS. We know that the code that lowers COPY of EFLAGS has
-/// to use the stack, and if we don't adjust the stack we clobber the first
-/// frame index.
-/// See X86InstrInfo::copyPhysReg.
-static bool usesTheStack(MachineFunction &MF) {
- MachineRegisterInfo &MRI = MF.getRegInfo();
-
- for (MachineRegisterInfo::reg_iterator ri = MRI.reg_begin(X86::EFLAGS),
- re = MRI.reg_end(); ri != re; ++ri)
- if (ri->isCopy())
- return true;
+static unsigned calculateSetFPREG(uint64_t SPAdjust) {
+ // Win64 ABI has a less restrictive limitation of 240; 128 works equally well
+ // and might require smaller successive adjustments.
+ const uint64_t Win64MaxSEHOffset = 128;
+ uint64_t SEHFrameOffset = std::min(SPAdjust, Win64MaxSEHOffset);
+ // Win64 ABI requires 16-byte alignment for the UWOP_SET_FPREG opcode.
+ return SEHFrameOffset & -16;
+}
- return false;
+// If we're forcing a stack realignment we can't rely on just the frame
+// 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) {
+ 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();
+ if (ForceStackAlign) {
+ if (MFI->hasCalls())
+ MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
+ else if (MaxAlign < SlotSize)
+ MaxAlign = SlotSize;
+ }
+ return MaxAlign;
}
/// 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
/// generate the exception handling frames.
-void X86FrameLowering::emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front(); // Prologue goes in entry BB.
+
+/*
+ Here's a gist of what gets emitted:
+
+ ; Establish frame pointer, if needed
+ [if needs FP]
+ push %rbp
+ .cfi_def_cfa_offset 16
+ .cfi_offset %rbp, -16
+ .seh_pushreg %rpb
+ mov %rsp, %rbp
+ .cfi_def_cfa_register %rbp
+
+ ; Spill general-purpose registers
+ [for all callee-saved GPRs]
+ pushq %<reg>
+ [if not needs FP]
+ .cfi_def_cfa_offset (offset from RETADDR)
+ .seh_pushreg %<reg>
+
+ ; If the required stack alignment > default stack alignment
+ ; rsp needs to be re-aligned. This creates a "re-alignment gap"
+ ; of unknown size in the stack frame.
+ [if stack needs re-alignment]
+ and $MASK, %rsp
+
+ ; Allocate space for locals
+ [if target is Windows and allocated space > 4096 bytes]
+ ; Windows needs special care for allocations larger
+ ; than one page.
+ mov $NNN, %rax
+ call ___chkstk_ms/___chkstk
+ sub %rax, %rsp
+ [else]
+ sub $NNN, %rsp
+
+ [if needs FP]
+ .seh_stackalloc (size of XMM spill slots)
+ .seh_setframe %rbp, SEHFrameOffset ; = size of all spill slots
+ [else]
+ .seh_stackalloc NNN
+
+ ; Spill XMMs
+ ; Note, that while only Windows 64 ABI specifies XMMs as callee-preserved,
+ ; they may get spilled on any platform, if the current function
+ ; calls @llvm.eh.unwind.init
+ [if needs FP]
+ [for all callee-saved XMM registers]
+ movaps %<xmm reg>, -MMM(%rbp)
+ [for all callee-saved XMM registers]
+ .seh_savexmm %<xmm reg>, (-MMM + SEHFrameOffset)
+ ; i.e. the offset relative to (%rbp - SEHFrameOffset)
+ [else]
+ [for all callee-saved XMM registers]
+ movaps %<xmm reg>, KKK(%rsp)
+ [for all callee-saved XMM registers]
+ .seh_savexmm %<xmm reg>, KKK
+
+ .seh_endprologue
+
+ [if needs base pointer]
+ mov %rsp, %rbx
+ [if needs to restore base pointer]
+ mov %rsp, -MMM(%rbp)
+
+ ; Emit CFI info
+ [if needs FP]
+ [for all callee-saved registers]
+ .cfi_offset %<reg>, (offset from %rbp)
+ [else]
+ .cfi_def_cfa_offset (offset from RETADDR)
+ [for all callee-saved registers]
+ .cfi_offset %<reg>, (offset from %rsp)
+
+ Notes:
+ - .seh directives are emitted only for Windows 64 ABI
+ - .cfi directives are emitted for all other ABIs
+ - for 32-bit code, substitute %e?? registers for %r??
+*/
+
+void X86FrameLowering::emitPrologue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const {
+ assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
MachineBasicBlock::iterator MBBI = MBB.begin();
MachineFrameInfo *MFI = MF.getFrameInfo();
const Function *Fn = MF.getFunction();
- const X86RegisterInfo *RegInfo = TM.getRegisterInfo();
- const X86InstrInfo &TII = *TM.getInstrInfo();
+ 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>();
- bool needsFrameMoves = MMI.hasDebugInfo() ||
- Fn->needsUnwindTableEntry();
- uint64_t MaxAlign = MFI->getMaxAlignment(); // Desired stack alignment.
+ 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();
- bool IsLP64 = STI.isTarget64BitLP64();
- bool IsWin64 = STI.isTargetWin64();
+ // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
+ const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
+ bool IsWin64 = STI.isCallingConvWin64(Fn->getCallingConv());
+ // Not necessarily synonymous with IsWin64.
+ bool IsWinEH = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
+ bool NeedsWinEH = IsWinEH && Fn->needsUnwindTableEntry();
+ bool NeedsDwarfCFI =
+ !IsWinEH && (MMI.hasDebugInfo() || Fn->needsUnwindTableEntry());
bool UseLEA = STI.useLeaForSP();
- unsigned StackAlign = getStackAlignment();
unsigned SlotSize = RegInfo->getSlotSize();
unsigned FramePtr = RegInfo->getFrameRegister(MF);
+ const unsigned MachineFramePtr =
+ STI.isTarget64BitILP32()
+ ? getX86SubSuperRegister(FramePtr, MVT::i64, false)
+ : FramePtr;
unsigned StackPtr = RegInfo->getStackRegister();
unsigned BasePtr = RegInfo->getBaseRegister();
DebugLoc DL;
- // If we're forcing a stack realignment we can't rely on just the frame
- // 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.
- if (ForceStackAlign) {
- if (MFI->hasCalls())
- MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
- else if (MaxAlign < SlotSize)
- MaxAlign = SlotSize;
- }
-
// Add RETADDR move area to callee saved frame size.
int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
+ if (TailCallReturnAddrDelta && IsWinEH)
+ report_fatal_error("Can't handle guaranteed tail call under win64 yet");
+
if (TailCallReturnAddrDelta < 0)
X86FI->setCalleeSavedFrameSize(
X86FI->getCalleeSavedFrameSize() - TailCallReturnAddrDelta);
+ bool UseStackProbe = (STI.isOSWindows() && !STI.isTargetMachO());
+
+ // The default stack probe size is 4096 if the function has no stackprobesize
+ // attribute.
+ unsigned StackProbeSize = 4096;
+ if (Fn->hasFnAttribute("stack-probe-size"))
+ Fn->getFnAttribute("stack-probe-size")
+ .getValueAsString()
+ .getAsInteger(0, StackProbeSize);
+
// If this is x86-64 and the Red Zone is not disabled, if we are a leaf
// function, and use up to 128 bytes of stack space, don't have a frame
// pointer, calls, or dynamic alloca then we do not need to adjust the
// stack pointer (we fit in the Red Zone). We also check that we don't
// push and pop from the stack.
- if (Is64Bit && !Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
- Attribute::NoRedZone) &&
+ if (Is64Bit && !Fn->hasFnAttribute(Attribute::NoRedZone) &&
!RegInfo->needsStackRealignment(MF) &&
- !MFI->hasVarSizedObjects() && // No dynamic alloca.
- !MFI->adjustsStack() && // No calls.
- !IsWin64 && // Win64 has no Red Zone
- !usesTheStack(MF) && // Don't push and pop.
- !MF.getTarget().Options.EnableSegmentedStacks) { // Regular stack
+ !MFI->hasVarSizedObjects() && // No dynamic alloca.
+ !MFI->adjustsStack() && // No calls.
+ !IsWin64 && // Win64 has no Red Zone
+ !usesTheStack(MF) && // Don't push and pop.
+ !MF.shouldSplitStack()) { // Regular stack
uint64_t MinSize = X86FI->getCalleeSavedFrameSize();
if (HasFP) MinSize += SlotSize;
StackSize = std::max(MinSize, StackSize > 128 ? StackSize - 128 : 0);
if (TailCallReturnAddrDelta < 0) {
MachineInstr *MI =
BuildMI(MBB, MBBI, DL,
- TII.get(getSUBriOpcode(IsLP64, -TailCallReturnAddrDelta)),
+ TII.get(getSUBriOpcode(Uses64BitFramePtr, -TailCallReturnAddrDelta)),
StackPtr)
.addReg(StackPtr)
.addImm(-TailCallReturnAddrDelta)
if (HasFP) {
// Calculate required stack adjustment.
uint64_t FrameSize = StackSize - SlotSize;
- if (RegInfo->needsStackRealignment(MF)) {
- // Callee-saved registers are pushed on stack before the stack
- // is realigned.
- FrameSize -= X86FI->getCalleeSavedFrameSize();
- NumBytes = (FrameSize + MaxAlign - 1) / MaxAlign * MaxAlign;
- } else {
- NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize();
- }
+ // If required, include space for extra hidden slot for stashing base pointer.
+ if (X86FI->getRestoreBasePointer())
+ FrameSize += SlotSize;
+
+ NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize();
+
+ // Callee-saved registers are pushed on stack before the stack is realigned.
+ if (RegInfo->needsStackRealignment(MF) && !IsWinEH)
+ NumBytes = RoundUpToAlignment(NumBytes, MaxAlign);
// Get the offset of the stack slot for the EBP register, which is
// guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
// Save EBP/RBP into the appropriate stack slot.
BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
- .addReg(FramePtr, RegState::Kill)
+ .addReg(MachineFramePtr, RegState::Kill)
.setMIFlag(MachineInstr::FrameSetup);
- if (needsFrameMoves) {
+ if (NeedsDwarfCFI) {
// Mark the place where EBP/RBP was saved.
- MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL))
- .addSym(FrameLabel);
-
// Define the current CFA rule to use the provided offset.
- if (StackSize) {
- MachineLocation SPDst(MachineLocation::VirtualFP);
- MachineLocation SPSrc(MachineLocation::VirtualFP, 2 * stackGrowth);
- MMI.addFrameMove(FrameLabel, SPDst, SPSrc);
- } else {
- MachineLocation SPDst(StackPtr);
- MachineLocation SPSrc(StackPtr, stackGrowth);
- MMI.addFrameMove(FrameLabel, SPDst, SPSrc);
- }
+ assert(StackSize);
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr, 2 * stackGrowth));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
// Change the rule for the FramePtr to be an "offset" rule.
- MachineLocation FPDst(MachineLocation::VirtualFP, 2 * stackGrowth);
- MachineLocation FPSrc(FramePtr);
- MMI.addFrameMove(FrameLabel, FPDst, FPSrc);
+ unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(MachineFramePtr, true);
+ CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createOffset(nullptr,
+ DwarfFramePtr, 2 * stackGrowth));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
- // Update EBP with the new base value.
- BuildMI(MBB, MBBI, DL,
- TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), FramePtr)
- .addReg(StackPtr)
- .setMIFlag(MachineInstr::FrameSetup);
+ if (NeedsWinEH) {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_PushReg))
+ .addImm(FramePtr)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
- if (needsFrameMoves) {
- // Mark effective beginning of when frame pointer becomes valid.
- MCSymbol *FrameLabel = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL))
- .addSym(FrameLabel);
+ if (!IsWinEH) {
+ // Update EBP with the new base value.
+ BuildMI(MBB, MBBI, DL,
+ TII.get(Uses64BitFramePtr ? X86::MOV64rr : X86::MOV32rr),
+ FramePtr)
+ .addReg(StackPtr)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
+ if (NeedsDwarfCFI) {
+ // Mark effective beginning of when frame pointer becomes valid.
// Define the current CFA to use the EBP/RBP register.
- MachineLocation FPDst(FramePtr);
- MachineLocation FPSrc(MachineLocation::VirtualFP);
- MMI.addFrameMove(FrameLabel, FPDst, FPSrc);
+ unsigned DwarfFramePtr = RegInfo->getDwarfRegNum(MachineFramePtr, true);
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaRegister(nullptr, DwarfFramePtr));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
- // Mark the FramePtr as live-in in every block except the entry.
- for (MachineFunction::iterator I = llvm::next(MF.begin()), E = MF.end();
- I != E; ++I)
- I->addLiveIn(FramePtr);
+ // Mark the FramePtr as live-in in every block.
+ for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I)
+ I->addLiveIn(MachineFramePtr);
} else {
NumBytes = StackSize - X86FI->getCalleeSavedFrameSize();
}
(MBBI->getOpcode() == X86::PUSH32r ||
MBBI->getOpcode() == X86::PUSH64r)) {
PushedRegs = true;
- MBBI->setFlag(MachineInstr::FrameSetup);
+ unsigned Reg = MBBI->getOperand(0).getReg();
++MBBI;
- if (!HasFP && needsFrameMoves) {
+ if (!HasFP && NeedsDwarfCFI) {
// Mark callee-saved push instruction.
- MCSymbol *Label = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL)).addSym(Label);
-
// Define the current CFA rule to use the provided offset.
- unsigned Ptr = StackSize ? MachineLocation::VirtualFP : StackPtr;
- MachineLocation SPDst(Ptr);
- MachineLocation SPSrc(Ptr, StackOffset);
- MMI.addFrameMove(Label, SPDst, SPSrc);
+ assert(StackSize);
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr, StackOffset));
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
StackOffset += stackGrowth;
}
+
+ if (NeedsWinEH) {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_PushReg)).addImm(Reg).setMIFlag(
+ MachineInstr::FrameSetup);
+ }
}
// Realign stack after we pushed callee-saved registers (so that we'll be
// able to calculate their offsets from the frame pointer).
-
- // NOTE: We push the registers before realigning the stack, so
- // vector callee-saved (xmm) registers may be saved w/o proper
- // alignment in this way. However, currently these regs are saved in
- // stack slots (see X86FrameLowering::spillCalleeSavedRegisters()), so
- // this shouldn't be a problem.
- if (RegInfo->needsStackRealignment(MF)) {
+ // Don't do this for Win64, it needs to realign the stack after the prologue.
+ if (!IsWinEH && RegInfo->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(Is64Bit ? X86::AND64ri32 : X86::AND32ri), StackPtr)
- .addReg(StackPtr)
- .addImm(-MaxAlign)
- .setMIFlag(MachineInstr::FrameSetup);
+ 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();
// the callee has more arguments then the caller.
NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
- // If there is an ADD32ri or SUB32ri of ESP immediately after this
- // instruction, merge the two instructions.
- mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes);
-
// Adjust stack pointer: ESP -= numbytes.
// Windows and cygwin/mingw require a prologue helper routine when allocating
// responsible for adjusting the stack pointer. Touching the stack at 4K
// increments is necessary to ensure that the guard pages used by the OS
// virtual memory manager are allocated in correct sequence.
- if (NumBytes >= 4096 && STI.isTargetCOFF() && !STI.isTargetEnvMacho()) {
- const char *StackProbeSymbol;
- bool isSPUpdateNeeded = false;
-
- if (Is64Bit) {
- if (STI.isTargetCygMing())
- StackProbeSymbol = "___chkstk";
- else {
- StackProbeSymbol = "__chkstk";
- isSPUpdateNeeded = true;
- }
- } else if (STI.isTargetCygMing())
- StackProbeSymbol = "_alloca";
- else
- StackProbeSymbol = "_chkstk";
-
+ uint64_t AlignedNumBytes = NumBytes;
+ if (IsWinEH && RegInfo->needsStackRealignment(MF))
+ AlignedNumBytes = RoundUpToAlignment(AlignedNumBytes, MaxAlign);
+ if (AlignedNumBytes >= StackProbeSize && UseStackProbe) {
// Check whether EAX is livein for this function.
bool isEAXAlive = isEAXLiveIn(MF);
if (Is64Bit) {
// Handle the 64-bit Windows ABI case where we need to call __chkstk.
// Function prologue is responsible for adjusting the stack pointer.
- BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri), X86::RAX)
- .addImm(NumBytes)
- .setMIFlag(MachineInstr::FrameSetup);
+ if (isUInt<32>(NumBytes)) {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
+ .addImm(NumBytes)
+ .setMIFlag(MachineInstr::FrameSetup);
+ } else if (isInt<32>(NumBytes)) {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri32), X86::RAX)
+ .addImm(NumBytes)
+ .setMIFlag(MachineInstr::FrameSetup);
+ } else {
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri), X86::RAX)
+ .addImm(NumBytes)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
} else {
// Allocate NumBytes-4 bytes on stack in case of isEAXAlive.
// We'll also use 4 already allocated bytes for EAX.
.setMIFlag(MachineInstr::FrameSetup);
}
- BuildMI(MBB, MBBI, DL,
- TII.get(Is64Bit ? X86::W64ALLOCA : X86::CALLpcrel32))
- .addExternalSymbol(StackProbeSymbol)
- .addReg(StackPtr, RegState::Define | RegState::Implicit)
- .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit)
- .setMIFlag(MachineInstr::FrameSetup);
+ // Save a pointer to the MI where we set AX.
+ MachineBasicBlock::iterator SetRAX = MBBI;
+ --SetRAX;
+
+ // Call __chkstk, __chkstk_ms, or __alloca.
+ emitStackProbeCall(MF, MBB, MBBI, DL);
- // MSVC x64's __chkstk needs to adjust %rsp.
- // FIXME: %rax preserves the offset and should be available.
- if (isSPUpdateNeeded)
- emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, IsLP64,
- UseLEA, TII, *RegInfo);
+ // Apply the frame setup flag to all inserted instrs.
+ for (; SetRAX != MBBI; ++SetRAX)
+ SetRAX->setFlag(MachineInstr::FrameSetup);
if (isEAXAlive) {
- // Restore EAX
- MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),
- X86::EAX),
- StackPtr, false, NumBytes - 4);
- MI->setFlag(MachineInstr::FrameSetup);
- MBB.insert(MBBI, MI);
+ // Restore EAX
+ MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),
+ X86::EAX),
+ StackPtr, false, NumBytes - 4);
+ MI->setFlag(MachineInstr::FrameSetup);
+ MBB.insert(MBBI, MI);
}
- } else if (NumBytes)
- emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, IsLP64,
+ } else if (NumBytes) {
+ emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, Uses64BitFramePtr,
UseLEA, TII, *RegInfo);
+ }
+
+ if (NeedsWinEH && NumBytes)
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_StackAlloc))
+ .addImm(NumBytes)
+ .setMIFlag(MachineInstr::FrameSetup);
+
+ int SEHFrameOffset = 0;
+ if (IsWinEH && HasFP) {
+ SEHFrameOffset = calculateSetFPREG(NumBytes);
+ if (SEHFrameOffset)
+ addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(X86::LEA64r), FramePtr),
+ StackPtr, false, SEHFrameOffset);
+ else
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64rr), FramePtr).addReg(StackPtr);
+
+ if (NeedsWinEH)
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_SetFrame))
+ .addImm(FramePtr)
+ .addImm(SEHFrameOffset)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
+
+ while (MBBI != MBB.end() && MBBI->getFlag(MachineInstr::FrameSetup)) {
+ const MachineInstr *FrameInstr = &*MBBI;
+ ++MBBI;
+
+ if (NeedsWinEH) {
+ int FI;
+ if (unsigned Reg = TII.isStoreToStackSlot(FrameInstr, FI)) {
+ if (X86::FR64RegClass.contains(Reg)) {
+ int Offset = getFrameIndexOffset(MF, FI);
+ Offset += SEHFrameOffset;
+
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_SaveXMM))
+ .addImm(Reg)
+ .addImm(Offset)
+ .setMIFlag(MachineInstr::FrameSetup);
+ }
+ }
+ }
+ }
+
+ if (NeedsWinEH)
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_EndPrologue))
+ .setMIFlag(MachineInstr::FrameSetup);
+
+ // 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 (IsWinEH && RegInfo->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();
+ }
// 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)) {
- // Update the frame pointer with the current stack pointer.
- unsigned Opc = Is64Bit ? X86::MOV64rr : X86::MOV32rr;
+ // 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.
+ 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 (( (!HasFP && NumBytes) || PushedRegs) && needsFrameMoves) {
+ if (((!HasFP && NumBytes) || PushedRegs) && NeedsDwarfCFI) {
// Mark end of stack pointer adjustment.
- MCSymbol *Label = MMI.getContext().CreateTempSymbol();
- BuildMI(MBB, MBBI, DL, TII.get(X86::PROLOG_LABEL))
- .addSym(Label);
-
if (!HasFP && NumBytes) {
// Define the current CFA rule to use the provided offset.
- if (StackSize) {
- MachineLocation SPDst(MachineLocation::VirtualFP);
- MachineLocation SPSrc(MachineLocation::VirtualFP,
- -StackSize + stackGrowth);
- MMI.addFrameMove(Label, SPDst, SPSrc);
- } else {
- MachineLocation SPDst(StackPtr);
- MachineLocation SPSrc(StackPtr, stackGrowth);
- MMI.addFrameMove(Label, SPDst, SPSrc);
- }
+ assert(StackSize);
+ unsigned CFIIndex = MMI.addFrameInst(
+ MCCFIInstruction::createDefCfaOffset(nullptr,
+ -StackSize + stackGrowth));
+
+ BuildMI(MBB, MBBI, DL, TII.get(TargetOpcode::CFI_INSTRUCTION))
+ .addCFIIndex(CFIIndex);
}
// Emit DWARF info specifying the offsets of the callee-saved registers.
if (PushedRegs)
- emitCalleeSavedFrameMoves(MF, Label, HasFP ? FramePtr : StackPtr);
+ emitCalleeSavedFrameMoves(MBB, MBBI, DL);
}
-
- // Darwin 10.7 and greater has support for compact unwind encoding.
- if (STI.getTargetTriple().isMacOSX() &&
- !STI.getTargetTriple().isMacOSXVersionLT(10, 7))
- MMI.setCompactUnwindEncoding(getCompactUnwindEncoding(MF));
}
void X86FrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- const X86RegisterInfo *RegInfo = TM.getRegisterInfo();
- const X86InstrInfo &TII = *TM.getInstrInfo();
+ const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
+ const X86RegisterInfo *RegInfo = STI.getRegisterInfo();
+ const TargetInstrInfo &TII = *STI.getInstrInfo();
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
assert(MBBI != MBB.end() && "Returning block has no instructions");
unsigned RetOpcode = MBBI->getOpcode();
DebugLoc DL = MBBI->getDebugLoc();
bool Is64Bit = STI.is64Bit();
- bool IsLP64 = STI.isTarget64BitLP64();
- bool UseLEA = STI.useLeaForSP();
- unsigned StackAlign = getStackAlignment();
+ // standard x86_64 and NaCl use 64-bit frame/stack pointers, x32 - 32-bit.
+ const bool Uses64BitFramePtr = STI.isTarget64BitLP64() || STI.isTargetNaCl64();
+ bool HasFP = hasFP(MF);
+ const bool Is64BitILP32 = STI.isTarget64BitILP32();
unsigned SlotSize = RegInfo->getSlotSize();
unsigned FramePtr = RegInfo->getFrameRegister(MF);
+ unsigned MachineFramePtr =
+ Is64BitILP32 ? getX86SubSuperRegister(FramePtr, MVT::i64, false)
+ : FramePtr;
unsigned StackPtr = RegInfo->getStackRegister();
+ bool IsWinEH = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
+ bool NeedsWinEH = IsWinEH && MF.getFunction()->needsUnwindTableEntry();
+ bool UseLEAForSP = false;
+
+ // We can't use LEA instructions for adjusting the stack pointer if this is a
+ // leaf function in the Win64 ABI. Only ADD instructions may be used to
+ // deallocate the stack.
+ if (STI.useLeaForSP()) {
+ if (!IsWinEH) {
+ // We *aren't* using the Win64 ABI which means we are free to use LEA.
+ UseLEAForSP = true;
+ } else if (HasFP) {
+ // We *have* a frame pointer which means we are permitted to use LEA.
+ UseLEAForSP = true;
+ }
+ }
+
switch (RetOpcode) {
default:
- llvm_unreachable("Can only insert epilog into returning blocks");
- case X86::RET:
- case X86::RETI:
+ llvm_unreachable("Can only insert epilogue into returning blocks");
+ case X86::RETQ:
+ case X86::RETL:
+ case X86::RETIL:
+ case X86::RETIQ:
case X86::TCRETURNdi:
case X86::TCRETURNri:
case X86::TCRETURNmi:
// Get the number of bytes to allocate from the FrameInfo.
uint64_t StackSize = MFI->getStackSize();
- uint64_t MaxAlign = MFI->getMaxAlignment();
+ uint64_t MaxAlign = calculateMaxStackAlign(MF);
unsigned CSSize = X86FI->getCalleeSavedFrameSize();
uint64_t NumBytes = 0;
- // If we're forcing a stack realignment we can't rely on just the frame
- // 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.
- if (ForceStackAlign) {
- if (MFI->hasCalls())
- MaxAlign = (StackAlign > MaxAlign) ? StackAlign : MaxAlign;
- else
- MaxAlign = MaxAlign ? MaxAlign : 4;
- }
-
if (hasFP(MF)) {
// Calculate required stack adjustment.
uint64_t FrameSize = StackSize - SlotSize;
- if (RegInfo->needsStackRealignment(MF)) {
- // Callee-saved registers were pushed on stack before the stack
- // was realigned.
- FrameSize -= CSSize;
- NumBytes = (FrameSize + MaxAlign - 1) / MaxAlign * MaxAlign;
- } else {
- NumBytes = FrameSize - CSSize;
- }
+ NumBytes = FrameSize - CSSize;
+
+ // Callee-saved registers were pushed on stack before the stack was
+ // realigned.
+ if (RegInfo->needsStackRealignment(MF) && !IsWinEH)
+ NumBytes = RoundUpToAlignment(FrameSize, MaxAlign);
// Pop EBP.
BuildMI(MBB, MBBI, DL,
- TII.get(Is64Bit ? X86::POP64r : X86::POP32r), FramePtr);
+ TII.get(Is64Bit ? X86::POP64r : X86::POP32r), MachineFramePtr);
} else {
NumBytes = StackSize - CSSize;
}
+ uint64_t SEHStackAllocAmt = NumBytes;
// Skip the callee-saved pop instructions.
while (MBBI != MBB.begin()) {
- MachineBasicBlock::iterator PI = prior(MBBI);
+ MachineBasicBlock::iterator PI = std::prev(MBBI);
unsigned Opc = PI->getOpcode();
if (Opc != X86::POP32r && Opc != X86::POP64r && Opc != X86::DBG_VALUE &&
if (RegInfo->needsStackRealignment(MF) || MFI->hasVarSizedObjects()) {
if (RegInfo->needsStackRealignment(MF))
MBBI = FirstCSPop;
- if (CSSize != 0) {
- unsigned Opc = getLEArOpcode(IsLP64);
+ unsigned SEHFrameOffset = calculateSetFPREG(SEHStackAllocAmt);
+ uint64_t LEAAmount = IsWinEH ? SEHStackAllocAmt - SEHFrameOffset : -CSSize;
+
+ // There are only two legal forms of epilogue:
+ // - add SEHAllocationSize, %rsp
+ // - lea SEHAllocationSize(%FramePtr), %rsp
+ //
+ // 'mov %FramePtr, %rsp' will not be recognized as an epilogue sequence.
+ // However, we may use this sequence if we have a frame pointer because the
+ // effects of the prologue can safely be undone.
+ if (LEAAmount != 0) {
+ unsigned Opc = getLEArOpcode(Uses64BitFramePtr);
addRegOffset(BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr),
- FramePtr, false, -CSSize);
+ FramePtr, false, LEAAmount);
+ --MBBI;
} else {
- unsigned Opc = (Is64Bit ? X86::MOV64rr : X86::MOV32rr);
+ unsigned Opc = (Uses64BitFramePtr ? X86::MOV64rr : X86::MOV32rr);
BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
.addReg(FramePtr);
+ --MBBI;
}
} else if (NumBytes) {
// Adjust stack pointer back: ESP += numbytes.
- emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, IsLP64, UseLEA,
- TII, *RegInfo);
+ emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, Uses64BitFramePtr,
+ UseLEAForSP, TII, *RegInfo);
+ --MBBI;
}
+ // Windows unwinder will not invoke function's exception handler if IP is
+ // either in prologue or in epilogue. This behavior causes a problem when a
+ // call immediately precedes an epilogue, because the return address points
+ // into the epilogue. To cope with that, we insert an epilogue marker here,
+ // then replace it with a 'nop' if it ends up immediately after a CALL in the
+ // final emitted code.
+ if (NeedsWinEH)
+ BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_Epilogue));
+
// We're returning from function via eh_return.
if (RetOpcode == X86::EH_RETURN || RetOpcode == X86::EH_RETURN64) {
MBBI = MBB.getLastNonDebugInstr();
MachineOperand &DestAddr = MBBI->getOperand(0);
assert(DestAddr.isReg() && "Offset should be in register!");
BuildMI(MBB, MBBI, DL,
- TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),
+ TII.get(Uses64BitFramePtr ? X86::MOV64rr : X86::MOV32rr),
StackPtr).addReg(DestAddr.getReg());
} else if (RetOpcode == X86::TCRETURNri || RetOpcode == X86::TCRETURNdi ||
RetOpcode == X86::TCRETURNmi ||
if (Offset) {
// Check for possible merge with preceding ADD instruction.
Offset += mergeSPUpdates(MBB, MBBI, StackPtr, true);
- emitSPUpdate(MBB, MBBI, StackPtr, Offset, Is64Bit, IsLP64,
- UseLEA, TII, *RegInfo);
+ emitSPUpdate(MBB, MBBI, StackPtr, Offset, Is64Bit, Uses64BitFramePtr,
+ UseLEAForSP, TII, *RegInfo);
}
// Jump to label or value in register.
+ bool IsWin64 = STI.isTargetWin64();
if (RetOpcode == X86::TCRETURNdi || RetOpcode == X86::TCRETURNdi64) {
- MachineInstrBuilder MIB =
- BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNdi)
- ? X86::TAILJMPd : X86::TAILJMPd64));
+ unsigned Op = (RetOpcode == X86::TCRETURNdi)
+ ? X86::TAILJMPd
+ : (IsWin64 ? X86::TAILJMPd64_REX : X86::TAILJMPd64);
+ MachineInstrBuilder MIB = BuildMI(MBB, MBBI, DL, TII.get(Op));
if (JumpTarget.isGlobal())
MIB.addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
JumpTarget.getTargetFlags());
JumpTarget.getTargetFlags());
}
} else if (RetOpcode == X86::TCRETURNmi || RetOpcode == X86::TCRETURNmi64) {
- MachineInstrBuilder MIB =
- BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNmi)
- ? X86::TAILJMPm : X86::TAILJMPm64));
+ unsigned Op = (RetOpcode == X86::TCRETURNmi)
+ ? X86::TAILJMPm
+ : (IsWin64 ? X86::TAILJMPm64_REX : X86::TAILJMPm64);
+ MachineInstrBuilder MIB = BuildMI(MBB, MBBI, DL, TII.get(Op));
for (unsigned i = 0; i != 5; ++i)
MIB.addOperand(MBBI->getOperand(i));
} else if (RetOpcode == X86::TCRETURNri64) {
- BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPr64)).
- addReg(JumpTarget.getReg(), RegState::Kill);
+ BuildMI(MBB, MBBI, DL,
+ TII.get(IsWin64 ? X86::TAILJMPr64_REX : X86::TAILJMPr64))
+ .addReg(JumpTarget.getReg(), RegState::Kill);
} else {
BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPr)).
addReg(JumpTarget.getReg(), RegState::Kill);
}
- MachineInstr *NewMI = prior(MBBI);
+ MachineInstr *NewMI = std::prev(MBBI);
NewMI->copyImplicitOps(MF, MBBI);
// Delete the pseudo instruction TCRETURN.
MBB.erase(MBBI);
- } else if ((RetOpcode == X86::RET || RetOpcode == X86::RETI) &&
+ } else if ((RetOpcode == X86::RETQ || RetOpcode == X86::RETL ||
+ RetOpcode == X86::RETIQ || RetOpcode == X86::RETIL) &&
(X86FI->getTCReturnAddrDelta() < 0)) {
// Add the return addr area delta back since we are not tail calling.
int delta = -1*X86FI->getTCReturnAddrDelta();
// Check for possible merge with preceding ADD instruction.
delta += mergeSPUpdates(MBB, MBBI, StackPtr, true);
- emitSPUpdate(MBB, MBBI, StackPtr, delta, Is64Bit, IsLP64, UseLEA, TII,
- *RegInfo);
+ emitSPUpdate(MBB, MBBI, StackPtr, delta, Is64Bit, Uses64BitFramePtr,
+ UseLEAForSP, TII, *RegInfo);
}
}
-int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF, int FI) const {
+int X86FrameLowering::getFrameIndexOffset(const MachineFunction &MF,
+ int FI) const {
const X86RegisterInfo *RegInfo =
- static_cast<const X86RegisterInfo*>(MF.getTarget().getRegisterInfo());
+ MF.getSubtarget<X86Subtarget>().getRegisterInfo();
const MachineFrameInfo *MFI = MF.getFrameInfo();
+ // Offset will hold the offset from the stack pointer at function entry to the
+ // object.
+ // We need to factor in additional offsets applied during the prologue to the
+ // frame, base, and stack pointer depending on which is used.
int Offset = MFI->getObjectOffset(FI) - getOffsetOfLocalArea();
+ const X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
+ unsigned CSSize = X86FI->getCalleeSavedFrameSize();
uint64_t StackSize = MFI->getStackSize();
+ unsigned SlotSize = RegInfo->getSlotSize();
+ bool HasFP = hasFP(MF);
+ bool IsWinEH = MF.getTarget().getMCAsmInfo()->usesWindowsCFI();
+ int64_t FPDelta = 0;
+
+ if (IsWinEH) {
+ assert(!MFI->hasCalls() || (StackSize % 16) == 8);
+
+ // Calculate required stack adjustment.
+ uint64_t FrameSize = StackSize - SlotSize;
+ // If required, include space for extra hidden slot for stashing base pointer.
+ if (X86FI->getRestoreBasePointer())
+ FrameSize += SlotSize;
+ uint64_t NumBytes = FrameSize - CSSize;
+
+ uint64_t SEHFrameOffset = calculateSetFPREG(NumBytes);
+ if (FI && FI == X86FI->getFAIndex())
+ return -SEHFrameOffset;
+
+ // FPDelta is the offset from the "traditional" FP location of the old base
+ // pointer followed by return address and the location required by the
+ // restricted Win64 prologue.
+ // Add FPDelta to all offsets below that go through the frame pointer.
+ FPDelta = FrameSize - SEHFrameOffset;
+ assert((!MFI->hasCalls() || (FPDelta % 16) == 0) &&
+ "FPDelta isn't aligned per the Win64 ABI!");
+ }
+
if (RegInfo->hasBasePointer(MF)) {
- assert (hasFP(MF) && "VLAs and dynamic stack realign, but no FP?!");
+ assert(HasFP && "VLAs and dynamic stack realign, but no FP?!");
if (FI < 0) {
// Skip the saved EBP.
- return Offset + RegInfo->getSlotSize();
+ return Offset + SlotSize + FPDelta;
} else {
assert((-(Offset + StackSize)) % MFI->getObjectAlignment(FI) == 0);
return Offset + StackSize;
} else if (RegInfo->needsStackRealignment(MF)) {
if (FI < 0) {
// Skip the saved EBP.
- return Offset + RegInfo->getSlotSize();
+ return Offset + SlotSize + FPDelta;
} else {
assert((-(Offset + StackSize)) % MFI->getObjectAlignment(FI) == 0);
return Offset + StackSize;
}
// FIXME: Support tail calls
} else {
- if (!hasFP(MF))
+ if (!HasFP)
return Offset + StackSize;
// Skip the saved EBP.
- Offset += RegInfo->getSlotSize();
+ Offset += SlotSize;
// Skip the RETADDR move area
- const X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
if (TailCallReturnAddrDelta < 0)
Offset -= TailCallReturnAddrDelta;
}
- return Offset;
+ return Offset + FPDelta;
}
int X86FrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
unsigned &FrameReg) const {
const X86RegisterInfo *RegInfo =
- static_cast<const X86RegisterInfo*>(MF.getTarget().getRegisterInfo());
+ 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.
return getFrameIndexOffset(MF, FI);
}
-bool X86FrameLowering::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
- const TargetRegisterInfo *TRI) const {
- if (CSI.empty())
- return false;
+// Simplified from getFrameIndexOffset keeping only StackPointer cases
+int X86FrameLowering::getFrameIndexOffsetFromSP(const MachineFunction &MF, int FI) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ // Does not include any dynamic realign.
+ 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)
+ // We can always address StackSlots from RSP. We can usually (unless
+ // needsStackRealignment) address CSRs from RSP, but sometimes need to
+ // address them from RBP. FixedObjects can be placed anywhere in the stack
+ // frame depending on their specific requirements (i.e. we can actually
+ // refer to arguments to the function which are stored in the *callers*
+ // 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");
+
+ // We don't handle tail calls, and shouldn't be seeing them
+ // either.
+ int TailCallReturnAddrDelta =
+ MF.getInfo<X86MachineFunctionInfo>()->getTCReturnAddrDelta();
+ assert(!(TailCallReturnAddrDelta < 0) && "we don't handle this case!");
+#endif
+ }
- DebugLoc DL = MBB.findDebugLoc(MI);
+ // This is how the math works out:
+ //
+ // %rsp grows (i.e. gets lower) left to right. Each box below is
+ // one word (eight bytes). Obj0 is the stack slot we're trying to
+ // get to.
+ //
+ // ----------------------------------
+ // | BP | Obj0 | Obj1 | ... | ObjN |
+ // ----------------------------------
+ // ^ ^ ^ ^
+ // A B C E
+ //
+ // A is the incoming stack pointer.
+ // (B - A) is the local area offset (-8 for x86-64) [1]
+ // (C - A) is the Offset returned by MFI->getObjectOffset for Obj0 [2]
+ //
+ // |(E - B)| is the StackSize (absolute value, positive). For a
+ // stack that grown down, this works out to be (B - E). [3]
+ //
+ // E is also the value of %rsp after stack has been set up, and we
+ // want (C - E) -- the value we can add to %rsp to get to Obj0. Now
+ // (C - E) == (C - A) - (B - A) + (B - E)
+ // { Using [1], [2] and [3] above }
+ // == getObjectOffset - LocalAreaOffset + StackSize
+ //
- MachineFunction &MF = *MBB.getParent();
+ // Get the Offset from the StackPointer
+ int Offset = MFI->getObjectOffset(FI) - getOffsetOfLocalArea();
+
+ return Offset + StackSize;
+}
+// Simplified from getFrameIndexReference keeping only StackPointer cases
+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");
- unsigned SlotSize = STI.is64Bit() ? 8 : 4;
- unsigned FPReg = TRI->getFrameRegister(MF);
- unsigned CalleeFrameSize = 0;
+ FrameReg = RegInfo->getStackRegister();
+ return getFrameIndexOffsetFromSP(MF, FI);
+}
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+bool X86FrameLowering::assignCalleeSavedSpillSlots(
+ 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;
+ int SpillSlotOffset = getOffsetOfLocalArea() + X86FI->getTCReturnAddrDelta();
+
+ if (hasFP(MF)) {
+ // emitPrologue always spills frame register the first thing.
+ SpillSlotOffset -= SlotSize;
+ MFI->CreateFixedSpillStackObject(SlotSize, SpillSlotOffset);
+
+ // 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);
+ for (unsigned i = 0; i < CSI.size(); ++i) {
+ if (TRI->regsOverlap(CSI[i].getReg(),FPReg)) {
+ CSI.erase(CSI.begin() + i);
+ break;
+ }
+ }
+ }
+
+ // Assign slots for GPRs. It increases frame size.
+ for (unsigned i = CSI.size(); i != 0; --i) {
+ unsigned Reg = CSI[i - 1].getReg();
+
+ if (!X86::GR64RegClass.contains(Reg) && !X86::GR32RegClass.contains(Reg))
+ continue;
+
+ SpillSlotOffset -= SlotSize;
+ CalleeSavedFrameSize += SlotSize;
+
+ int SlotIndex = MFI->CreateFixedSpillStackObject(SlotSize, SpillSlotOffset);
+ CSI[i - 1].setFrameIdx(SlotIndex);
+ }
+
+ X86FI->setCalleeSavedFrameSize(CalleeSavedFrameSize);
+
+ // Assign slots for XMMs.
+ for (unsigned i = CSI.size(); i != 0; --i) {
+ unsigned Reg = CSI[i - 1].getReg();
+ if (X86::GR64RegClass.contains(Reg) || X86::GR32RegClass.contains(Reg))
+ continue;
+
+ const TargetRegisterClass *RC = RegInfo->getMinimalPhysRegClass(Reg);
+ // ensure alignment
+ SpillSlotOffset -= std::abs(SpillSlotOffset) % RC->getAlignment();
+ // spill into slot
+ SpillSlotOffset -= RC->getSize();
+ int SlotIndex =
+ MFI->CreateFixedSpillStackObject(RC->getSize(), SpillSlotOffset);
+ CSI[i - 1].setFrameIdx(SlotIndex);
+ MFI->ensureMaxAlignment(RC->getAlignment());
+ }
+
+ return true;
+}
+
+bool X86FrameLowering::spillCalleeSavedRegisters(
+ MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
+ const std::vector<CalleeSavedInfo> &CSI,
+ 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) {
- unsigned Reg = CSI[i-1].getReg();
- if (!X86::GR64RegClass.contains(Reg) &&
- !X86::GR32RegClass.contains(Reg))
+ unsigned Reg = CSI[i - 1].getReg();
+
+ if (!X86::GR64RegClass.contains(Reg) && !X86::GR32RegClass.contains(Reg))
continue;
// Add the callee-saved register as live-in. It's killed at the spill.
MBB.addLiveIn(Reg);
- if (Reg == FPReg)
- // X86RegisterInfo::emitPrologue will handle spilling of frame register.
- continue;
- CalleeFrameSize += SlotSize;
+
BuildMI(MBB, MI, DL, TII.get(Opc)).addReg(Reg, RegState::Kill)
.setMIFlag(MachineInstr::FrameSetup);
}
- X86FI->setCalleeSavedFrameSize(CalleeFrameSize);
-
// Make XMM regs spilled. X86 does not have ability of push/pop XMM.
// It can be done by spilling XMMs to stack frame.
- // Note that only Win64 ABI might spill XMMs.
for (unsigned i = CSI.size(); i != 0; --i) {
unsigned Reg = CSI[i-1].getReg();
- if (X86::GR64RegClass.contains(Reg) ||
- X86::GR32RegClass.contains(Reg))
+ if (X86::GR64RegClass.contains(Reg) || X86::GR32RegClass.contains(Reg))
continue;
// Add the callee-saved register as live-in. It's killed at the spill.
MBB.addLiveIn(Reg);
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
- TII.storeRegToStackSlot(MBB, MI, Reg, true, CSI[i-1].getFrameIdx(),
- RC, TRI);
+
+ TII.storeRegToStackSlot(MBB, MI, Reg, true, CSI[i - 1].getFrameIdx(), RC,
+ TRI);
+ --MI;
+ MI->setFlag(MachineInstr::FrameSetup);
+ ++MI;
}
return true;
DebugLoc DL = MBB.findDebugLoc(MI);
MachineFunction &MF = *MBB.getParent();
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
+ 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) {
if (X86::GR64RegClass.contains(Reg) ||
X86::GR32RegClass.contains(Reg))
continue;
+
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
- TII.loadRegFromStackSlot(MBB, MI, Reg, CSI[i].getFrameIdx(),
- RC, TRI);
+ TII.loadRegFromStackSlot(MBB, MI, Reg, CSI[i].getFrameIdx(), RC, TRI);
}
// POP GPRs.
- unsigned FPReg = TRI->getFrameRegister(MF);
unsigned Opc = STI.is64Bit() ? X86::POP64r : X86::POP32r;
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
if (!X86::GR64RegClass.contains(Reg) &&
!X86::GR32RegClass.contains(Reg))
continue;
- if (Reg == FPReg)
- // X86RegisterInfo::emitEpilogue will handle restoring of frame register.
- continue;
+
BuildMI(MBB, MI, DL, TII.get(Opc), Reg);
}
return true;
void
X86FrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
- RegScavenger *RS) const {
+ RegScavenger *RS) const {
MachineFrameInfo *MFI = MF.getFrameInfo();
- const X86RegisterInfo *RegInfo = TM.getRegisterInfo();
+ const X86RegisterInfo *RegInfo =
+ MF.getSubtarget<X86Subtarget>().getRegisterInfo();
unsigned SlotSize = RegInfo->getSlotSize();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- int32_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
+ int64_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
if (TailCallReturnAddrDelta < 0) {
// create RETURNADDR area
// }
// [EBP]
MFI->CreateFixedObject(-TailCallReturnAddrDelta,
- (-1U*SlotSize)+TailCallReturnAddrDelta, true);
- }
-
- if (hasFP(MF)) {
- assert((TailCallReturnAddrDelta <= 0) &&
- "The Delta should always be zero or negative");
- const TargetFrameLowering &TFI = *MF.getTarget().getFrameLowering();
-
- // Create a frame entry for the EBP register that must be saved.
- int FrameIdx = MFI->CreateFixedObject(SlotSize,
- -(int)SlotSize +
- TFI.getOffsetOfLocalArea() +
- TailCallReturnAddrDelta,
- true);
- assert(FrameIdx == MFI->getObjectIndexBegin() &&
- "Slot for EBP register must be last in order to be found!");
- (void)FrameIdx;
+ TailCallReturnAddrDelta - SlotSize, true);
}
// Spill the BasePtr if it's used.
/// and the properties of the function either one or two registers will be
/// needed. Set primary to true for the first register, false for the second.
static unsigned
-GetScratchRegister(bool Is64Bit, const MachineFunction &MF, bool Primary) {
+GetScratchRegister(bool Is64Bit, bool IsLP64, const MachineFunction &MF, bool Primary) {
CallingConv::ID CallingConvention = MF.getFunction()->getCallingConv();
// Erlang stuff.
return Primary ? X86::EBX : X86::EDI;
}
- if (Is64Bit)
- return Primary ? X86::R11 : X86::R12;
+ if (Is64Bit) {
+ if (IsLP64)
+ return Primary ? X86::R11 : X86::R12;
+ else
+ return Primary ? X86::R11D : X86::R12D;
+ }
bool IsNested = HasNestArgument(&MF);
// limit.
static const uint64_t kSplitStackAvailable = 256;
-void
-X86FrameLowering::adjustForSegmentedStacks(MachineFunction &MF) const {
- MachineBasicBlock &prologueMBB = MF.front();
+void X86FrameLowering::adjustForSegmentedStacks(
+ MachineFunction &MF, MachineBasicBlock &PrologueMBB) const {
+ assert(&PrologueMBB == &MF.front() &&
+ "Shrink-wrapping is not implemented yet");
MachineFrameInfo *MFI = MF.getFrameInfo();
- const X86InstrInfo &TII = *TM.getInstrInfo();
+ 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;
- unsigned ScratchReg = GetScratchRegister(Is64Bit, MF, true);
+ unsigned ScratchReg = GetScratchRegister(Is64Bit, IsLP64, MF, true);
assert(!MF.getRegInfo().isLiveIn(ScratchReg) &&
"Scratch register is live-in");
if (MF.getFunction()->isVarArg())
report_fatal_error("Segmented stacks do not support vararg functions.");
- if (!STI.isTargetLinux() && !STI.isTargetDarwin() &&
- !STI.isTargetWin32() && !STI.isTargetFreeBSD())
+ if (!STI.isTargetLinux() && !STI.isTargetDarwin() && !STI.isTargetWin32() &&
+ !STI.isTargetWin64() && !STI.isTargetFreeBSD() &&
+ !STI.isTargetDragonFly())
report_fatal_error("Segmented stacks not supported on this platform.");
+ // Eventually StackSize will be calculated by a link-time pass; which will
+ // also decide whether checking code needs to be injected into this particular
+ // prologue.
+ StackSize = MFI->getStackSize();
+
+ // Do not generate a prologue for functions with a stack of size zero
+ if (StackSize == 0)
+ return;
+
MachineBasicBlock *allocMBB = MF.CreateMachineBasicBlock();
MachineBasicBlock *checkMBB = MF.CreateMachineBasicBlock();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
// The MOV R10, RAX needs to be in a different block, since the RET we emit in
// allocMBB needs to be last (terminating) instruction.
- for (MachineBasicBlock::livein_iterator i = prologueMBB.livein_begin(),
- e = prologueMBB.livein_end(); i != e; i++) {
+ for (MachineBasicBlock::livein_iterator i = PrologueMBB.livein_begin(),
+ e = PrologueMBB.livein_end();
+ i != e; i++) {
allocMBB->addLiveIn(*i);
checkMBB->addLiveIn(*i);
}
if (IsNested)
- allocMBB->addLiveIn(X86::R10);
+ allocMBB->addLiveIn(IsLP64 ? X86::R10 : X86::R10D);
MF.push_front(allocMBB);
MF.push_front(checkMBB);
- // Eventually StackSize will be calculated by a link-time pass; which will
- // also decide whether checking code needs to be injected into this particular
- // prologue.
- StackSize = MFI->getStackSize();
-
// When the frame size is less than 256 we just compare the stack
// boundary directly to the value of the stack pointer, per gcc.
bool CompareStackPointer = StackSize < kSplitStackAvailable;
if (Is64Bit) {
if (STI.isTargetLinux()) {
TlsReg = X86::FS;
- TlsOffset = 0x70;
+ TlsOffset = IsLP64 ? 0x70 : 0x40;
} else if (STI.isTargetDarwin()) {
TlsReg = X86::GS;
TlsOffset = 0x60 + 90*8; // See pthread_machdep.h. Steal TLS slot 90.
+ } else if (STI.isTargetWin64()) {
+ TlsReg = X86::GS;
+ TlsOffset = 0x28; // pvArbitrary, reserved for application use
} else if (STI.isTargetFreeBSD()) {
TlsReg = X86::FS;
TlsOffset = 0x18;
+ } else if (STI.isTargetDragonFly()) {
+ TlsReg = X86::FS;
+ TlsOffset = 0x20; // use tls_tcb.tcb_segstack
} else {
report_fatal_error("Segmented stacks not supported on this platform.");
}
if (CompareStackPointer)
- ScratchReg = X86::RSP;
+ ScratchReg = IsLP64 ? X86::RSP : X86::ESP;
else
- BuildMI(checkMBB, DL, TII.get(X86::LEA64r), ScratchReg).addReg(X86::RSP)
+ BuildMI(checkMBB, DL, TII.get(IsLP64 ? X86::LEA64r : X86::LEA64_32r), ScratchReg).addReg(X86::RSP)
.addImm(1).addReg(0).addImm(-StackSize).addReg(0);
- BuildMI(checkMBB, DL, TII.get(X86::CMP64rm)).addReg(ScratchReg)
+ BuildMI(checkMBB, DL, TII.get(IsLP64 ? X86::CMP64rm : X86::CMP32rm)).addReg(ScratchReg)
.addReg(0).addImm(1).addReg(0).addImm(TlsOffset).addReg(TlsReg);
} else {
if (STI.isTargetLinux()) {
} else if (STI.isTargetWin32()) {
TlsReg = X86::FS;
TlsOffset = 0x14; // pvArbitrary, reserved for application use
+ } else if (STI.isTargetDragonFly()) {
+ TlsReg = X86::FS;
+ TlsOffset = 0x10; // use tls_tcb.tcb_segstack
} else if (STI.isTargetFreeBSD()) {
report_fatal_error("Segmented stacks not supported on FreeBSD i386.");
} else {
BuildMI(checkMBB, DL, TII.get(X86::LEA32r), ScratchReg).addReg(X86::ESP)
.addImm(1).addReg(0).addImm(-StackSize).addReg(0);
- if (STI.isTargetLinux() || STI.isTargetWin32()) {
+ if (STI.isTargetLinux() || STI.isTargetWin32() || STI.isTargetWin64() ||
+ STI.isTargetDragonFly()) {
BuildMI(checkMBB, DL, TII.get(X86::CMP32rm)).addReg(ScratchReg)
.addReg(0).addImm(0).addReg(0).addImm(TlsOffset).addReg(TlsReg);
} else if (STI.isTargetDarwin()) {
- // TlsOffset doesn't fit into a mod r/m byte so we need an extra register
+ // TlsOffset doesn't fit into a mod r/m byte so we need an extra register.
unsigned ScratchReg2;
bool SaveScratch2;
if (CompareStackPointer) {
- // The primary scratch register is available for holding the TLS offset
- ScratchReg2 = GetScratchRegister(Is64Bit, MF, true);
+ // The primary scratch register is available for holding the TLS offset.
+ ScratchReg2 = GetScratchRegister(Is64Bit, IsLP64, MF, true);
SaveScratch2 = false;
} else {
// Need to use a second register to hold the TLS offset
- ScratchReg2 = GetScratchRegister(Is64Bit, MF, false);
+ ScratchReg2 = GetScratchRegister(Is64Bit, IsLP64, MF, false);
- // Unfortunately, with fastcc the second scratch register may hold an arg
+ // Unfortunately, with fastcc the second scratch register may hold an
+ // argument.
SaveScratch2 = MF.getRegInfo().isLiveIn(ScratchReg2);
}
- // If Scratch2 is live-in then it needs to be saved
+ // If Scratch2 is live-in then it needs to be saved.
assert((!MF.getRegInfo().isLiveIn(ScratchReg2) || SaveScratch2) &&
"Scratch register is live-in and not saved");
// This jump is taken if SP >= (Stacklet Limit + Stack Space required).
// It jumps to normal execution of the function body.
- BuildMI(checkMBB, DL, TII.get(X86::JA_4)).addMBB(&prologueMBB);
+ BuildMI(checkMBB, DL, TII.get(X86::JA_1)).addMBB(&PrologueMBB);
// On 32 bit we first push the arguments size and then the frame size. On 64
// bit, we pass the stack frame size in r10 and the argument size in r11.
// Functions with nested arguments use R10, so it needs to be saved across
// the call to _morestack
+ const unsigned RegAX = IsLP64 ? X86::RAX : X86::EAX;
+ const unsigned Reg10 = IsLP64 ? X86::R10 : X86::R10D;
+ const unsigned Reg11 = IsLP64 ? X86::R11 : X86::R11D;
+ const unsigned MOVrr = IsLP64 ? X86::MOV64rr : X86::MOV32rr;
+ const unsigned MOVri = IsLP64 ? X86::MOV64ri : X86::MOV32ri;
+
if (IsNested)
- BuildMI(allocMBB, DL, TII.get(X86::MOV64rr), X86::RAX).addReg(X86::R10);
+ BuildMI(allocMBB, DL, TII.get(MOVrr), RegAX).addReg(Reg10);
- BuildMI(allocMBB, DL, TII.get(X86::MOV64ri), X86::R10)
+ BuildMI(allocMBB, DL, TII.get(MOVri), Reg10)
.addImm(StackSize);
- BuildMI(allocMBB, DL, TII.get(X86::MOV64ri), X86::R11)
+ BuildMI(allocMBB, DL, TII.get(MOVri), Reg11)
.addImm(X86FI->getArgumentStackSize());
- MF.getRegInfo().setPhysRegUsed(X86::R10);
- MF.getRegInfo().setPhysRegUsed(X86::R11);
+ MF.getRegInfo().setPhysRegUsed(Reg10);
+ MF.getRegInfo().setPhysRegUsed(Reg11);
} else {
BuildMI(allocMBB, DL, TII.get(X86::PUSHi32))
.addImm(X86FI->getArgumentStackSize());
}
// __morestack is in libgcc
- if (Is64Bit)
- BuildMI(allocMBB, DL, TII.get(X86::CALL64pcrel32))
- .addExternalSymbol("__morestack");
- else
- BuildMI(allocMBB, DL, TII.get(X86::CALLpcrel32))
- .addExternalSymbol("__morestack");
+ if (Is64Bit && MF.getTarget().getCodeModel() == CodeModel::Large) {
+ // Under the large code model, we cannot assume that __morestack lives
+ // within 2^31 bytes of the call site, so we cannot use pc-relative
+ // addressing. We cannot perform the call via a temporary register,
+ // as the rax register may be used to store the static chain, and all
+ // other suitable registers may be either callee-save or used for
+ // parameter passing. We cannot use the stack at this point either
+ // because __morestack manipulates the stack directly.
+ //
+ // To avoid these issues, perform an indirect call via a read-only memory
+ // location containing the address.
+ //
+ // This solution is not perfect, as it assumes that the .rodata section
+ // is laid out within 2^31 bytes of each function body, but this seems
+ // to be sufficient for JIT.
+ BuildMI(allocMBB, DL, TII.get(X86::CALL64m))
+ .addReg(X86::RIP)
+ .addImm(0)
+ .addReg(0)
+ .addExternalSymbol("__morestack_addr")
+ .addReg(0);
+ MF.getMMI().setUsesMorestackAddr(true);
+ } else {
+ if (Is64Bit)
+ BuildMI(allocMBB, DL, TII.get(X86::CALL64pcrel32))
+ .addExternalSymbol("__morestack");
+ else
+ BuildMI(allocMBB, DL, TII.get(X86::CALLpcrel32))
+ .addExternalSymbol("__morestack");
+ }
if (IsNested)
BuildMI(allocMBB, DL, TII.get(X86::MORESTACK_RET_RESTORE_R10));
else
BuildMI(allocMBB, DL, TII.get(X86::MORESTACK_RET));
- allocMBB->addSuccessor(&prologueMBB);
+ allocMBB->addSuccessor(&PrologueMBB);
checkMBB->addSuccessor(allocMBB);
- checkMBB->addSuccessor(&prologueMBB);
+ checkMBB->addSuccessor(&PrologueMBB);
#ifdef XDEBUG
MF.verify();
/// http://publications.uu.se/uu/fulltext/nbn_se_uu_diva-2688.pdf)
///
/// CheckStack:
-/// temp0 = sp - MaxStack
-/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
+/// temp0 = sp - MaxStack
+/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
/// OldStart:
-/// ...
+/// ...
/// IncStack:
-/// call inc_stack # doubles the stack space
-/// temp0 = sp - MaxStack
-/// if( temp0 < SP_LIMIT(P) ) goto IncStack else goto OldStart
-void X86FrameLowering::adjustForHiPEPrologue(MachineFunction &MF) const {
- const X86InstrInfo &TII = *TM.getInstrInfo();
+/// call inc_stack # doubles the stack space
+/// temp0 = sp - MaxStack
+/// 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 = TM.getRegisterInfo()->getSlotSize();
+ 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;
// If the stack frame needed is larger than the guaranteed then runtime checks
// and calls to "inc_stack_0" BIF should be inserted in the assembly prologue.
if (MaxStack > Guaranteed) {
- MachineBasicBlock &prologueMBB = MF.front();
+ assert(&PrologueMBB == &MF.front() &&
+ "Shrink-wrapping is not implemented yet");
MachineBasicBlock *stackCheckMBB = MF.CreateMachineBasicBlock();
MachineBasicBlock *incStackMBB = MF.CreateMachineBasicBlock();
- for (MachineBasicBlock::livein_iterator I = prologueMBB.livein_begin(),
- E = prologueMBB.livein_end(); I != E; I++) {
+ for (MachineBasicBlock::livein_iterator I = PrologueMBB.livein_begin(),
+ E = PrologueMBB.livein_end();
+ I != E; I++) {
stackCheckMBB->addLiveIn(*I);
incStackMBB->addLiveIn(*I);
}
SPLimitOffset = 0x4c;
}
- ScratchReg = GetScratchRegister(Is64Bit, MF, true);
+ ScratchReg = GetScratchRegister(Is64Bit, IsLP64, MF, true);
assert(!MF.getRegInfo().isLiveIn(ScratchReg) &&
"HiPE prologue scratch register is live-in");
// SPLimitOffset is in a fixed heap location (pointed by BP).
addRegOffset(BuildMI(stackCheckMBB, DL, TII.get(CMPop))
.addReg(ScratchReg), PReg, false, SPLimitOffset);
- BuildMI(stackCheckMBB, DL, TII.get(X86::JAE_4)).addMBB(&prologueMBB);
+ BuildMI(stackCheckMBB, DL, TII.get(X86::JAE_1)).addMBB(&PrologueMBB);
// Create new MBB for IncStack:
BuildMI(incStackMBB, DL, TII.get(CALLop)).
SPReg, false, -MaxStack);
addRegOffset(BuildMI(incStackMBB, DL, TII.get(CMPop))
.addReg(ScratchReg), PReg, false, SPLimitOffset);
- BuildMI(incStackMBB, DL, TII.get(X86::JLE_4)).addMBB(incStackMBB);
+ BuildMI(incStackMBB, DL, TII.get(X86::JLE_1)).addMBB(incStackMBB);
- stackCheckMBB->addSuccessor(&prologueMBB, 99);
+ stackCheckMBB->addSuccessor(&PrologueMBB, 99);
stackCheckMBB->addSuccessor(incStackMBB, 1);
- incStackMBB->addSuccessor(&prologueMBB, 99);
+ incStackMBB->addSuccessor(&PrologueMBB, 99);
incStackMBB->addSuccessor(incStackMBB, 1);
}
#ifdef XDEBUG
void X86FrameLowering::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
- const X86InstrInfo &TII = *TM.getInstrInfo();
- const X86RegisterInfo &RegInfo = *TM.getRegisterInfo();
+ const X86Subtarget &STI = MF.getSubtarget<X86Subtarget>();
+ const TargetInstrInfo &TII = *STI.getInstrInfo();
+ const X86RegisterInfo &RegInfo = *STI.getRegisterInfo();
unsigned StackPtr = RegInfo.getStackRegister();
- bool reseveCallFrame = hasReservedCallFrame(MF);
- int Opcode = I->getOpcode();
+ bool reserveCallFrame = hasReservedCallFrame(MF);
+ unsigned Opcode = I->getOpcode();
bool isDestroy = Opcode == TII.getCallFrameDestroyOpcode();
bool IsLP64 = STI.isTarget64BitLP64();
DebugLoc DL = I->getDebugLoc();
- uint64_t Amount = !reseveCallFrame ? I->getOperand(0).getImm() : 0;
- uint64_t CalleeAmt = isDestroy ? I->getOperand(1).getImm() : 0;
+ uint64_t Amount = !reserveCallFrame ? I->getOperand(0).getImm() : 0;
+ uint64_t InternalAmt = (isDestroy || Amount) ? I->getOperand(1).getImm() : 0;
I = MBB.erase(I);
- if (!reseveCallFrame) {
+ if (!reserveCallFrame) {
// If the stack pointer can be changed after prologue, turn the
// adjcallstackup instruction into a 'sub ESP, <amt>' and the
// adjcallstackdown instruction into 'add ESP, <amt>'
- // TODO: consider using push / pop instead of sub + store / add
if (Amount == 0)
return;
// We need to keep the stack aligned properly. To do this, we round the
// amount of space needed for the outgoing arguments up to the next
// alignment boundary.
- unsigned StackAlign = TM.getFrameLowering()->getStackAlignment();
- Amount = (Amount + StackAlign - 1) / StackAlign * StackAlign;
+ unsigned StackAlign = getStackAlignment();
+ Amount = RoundUpToAlignment(Amount, StackAlign);
- MachineInstr *New = 0;
- if (Opcode == TII.getCallFrameSetupOpcode()) {
- New = BuildMI(MF, DL, TII.get(getSUBriOpcode(IsLP64, Amount)),
- StackPtr)
- .addReg(StackPtr)
- .addImm(Amount);
- } else {
- assert(Opcode == TII.getCallFrameDestroyOpcode());
+ 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;
- // Factor out the amount the callee already popped.
- Amount -= CalleeAmt;
+ 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());
- if (Amount) {
unsigned Opc = getADDriOpcode(IsLP64, Amount);
New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
.addReg(StackPtr).addImm(Amount);
return;
}
- if (Opcode == TII.getCallFrameDestroyOpcode() && CalleeAmt) {
+ if (Opcode == TII.getCallFrameDestroyOpcode() && 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, CalleeAmt);
+ unsigned Opc = getSUBriOpcode(IsLP64, InternalAmt);
MachineInstr *New = BuildMI(MF, DL, TII.get(Opc), StackPtr)
- .addReg(StackPtr).addImm(CalleeAmt);
+ .addReg(StackPtr).addImm(InternalAmt);
// The EFLAGS implicit def is dead.
New->getOperand(3).setIsDead();
// 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 && !llvm::prior(I)->isCall())
+ while (I != B && !std::prev(I)->isCall())
--I;
MBB.insert(I, New);
}
projects / oota-llvm.git / blobdiff