//
//===----------------------------------------------------------------------===//
//
-// This file contains the X86 implementation of the MRegisterInfo class. This
-// file is responsible for the frame pointer elimination optimization on X86.
+// This file contains the X86 implementation of the TargetRegisterInfo class.
+// This file is responsible for the frame pointer elimination optimization
+// on X86.
//
//===----------------------------------------------------------------------===//
#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineLocation.h"
#include "llvm/CodeGen/MachineModuleInfo.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/Support/Compiler.h"
using namespace llvm;
X86RegisterInfo::X86RegisterInfo(X86TargetMachine &tm,
const TargetInstrInfo &tii)
- : X86GenRegisterInfo(X86::ADJCALLSTACKDOWN, X86::ADJCALLSTACKUP),
+ : X86GenRegisterInfo(tm.getSubtarget<X86Subtarget>().is64Bit() ?
+ X86::ADJCALLSTACKDOWN64 :
+ X86::ADJCALLSTACKDOWN32,
+ tm.getSubtarget<X86Subtarget>().is64Bit() ?
+ X86::ADJCALLSTACKUP64 :
+ X86::ADJCALLSTACKUP32),
TM(tm), TII(tii) {
// Cache some information.
const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
Is64Bit = Subtarget->is64Bit();
+ IsWin64 = Subtarget->isTargetWin64();
StackAlign = TM.getFrameInfo()->getStackAlignment();
if (Is64Bit) {
SlotSize = 8;
}
}
+const TargetRegisterClass *X86RegisterInfo::getPointerRegClass() const {
+ const X86Subtarget *Subtarget = &TM.getSubtarget<X86Subtarget>();
+ if (Subtarget->is64Bit())
+ return &X86::GR64RegClass;
+ else
+ return &X86::GR32RegClass;
+}
+
const TargetRegisterClass *
X86RegisterInfo::getCrossCopyRegClass(const TargetRegisterClass *RC) const {
- if (RC == &X86::CCRRegClass)
+ if (RC == &X86::CCRRegClass) {
if (Is64Bit)
return &X86::GR64RegClass;
else
return &X86::GR32RegClass;
- return NULL;
-}
-
-void X86RegisterInfo::reMaterialize(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator I,
- unsigned DestReg,
- const MachineInstr *Orig) const {
- // MOV32r0 etc. are implemented with xor which clobbers condition code.
- // Re-materialize them as movri instructions to avoid side effects.
- switch (Orig->getOpcode()) {
- case X86::MOV8r0:
- BuildMI(MBB, I, TII.get(X86::MOV8ri), DestReg).addImm(0);
- break;
- case X86::MOV16r0:
- BuildMI(MBB, I, TII.get(X86::MOV16ri), DestReg).addImm(0);
- break;
- case X86::MOV32r0:
- BuildMI(MBB, I, TII.get(X86::MOV32ri), DestReg).addImm(0);
- break;
- case X86::MOV64r0:
- BuildMI(MBB, I, TII.get(X86::MOV64ri32), DestReg).addImm(0);
- break;
- default: {
- MachineInstr *MI = Orig->clone();
- MI->getOperand(0).setReg(DestReg);
- MBB.insert(I, MI);
- break;
- }
}
+ return NULL;
}
const unsigned *
X86RegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
+ bool callsEHReturn = false;
+
+ if (MF) {
+ const MachineFrameInfo *MFI = MF->getFrameInfo();
+ const MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
+ callsEHReturn = (MMI ? MMI->callsEHReturn() : false);
+ }
+
static const unsigned CalleeSavedRegs32Bit[] = {
X86::ESI, X86::EDI, X86::EBX, X86::EBP, 0
};
X86::RBX, X86::R12, X86::R13, X86::R14, X86::R15, X86::RBP, 0
};
- if (Is64Bit)
- return CalleeSavedRegs64Bit;
- else {
- if (MF) {
- MachineFrameInfo *MFI = MF->getFrameInfo();
- MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
- if (MMI && MMI->callsEHReturn())
- return CalleeSavedRegs32EHRet;
- }
- return CalleeSavedRegs32Bit;
+ static const unsigned CalleeSavedRegs64EHRet[] = {
+ X86::RAX, X86::RDX, X86::RBX, X86::R12,
+ X86::R13, X86::R14, X86::R15, X86::RBP, 0
+ };
+
+ static const unsigned CalleeSavedRegsWin64[] = {
+ X86::RBX, X86::RBP, X86::RDI, X86::RSI,
+ X86::R12, X86::R13, X86::R14, X86::R15,
+ X86::XMM6, X86::XMM7, X86::XMM8, X86::XMM9,
+ X86::XMM10, X86::XMM11, X86::XMM12, X86::XMM13,
+ X86::XMM14, X86::XMM15, 0
+ };
+
+ if (Is64Bit) {
+ if (IsWin64)
+ return CalleeSavedRegsWin64;
+ else
+ return (callsEHReturn ? CalleeSavedRegs64EHRet : CalleeSavedRegs64Bit);
+ } else {
+ return (callsEHReturn ? CalleeSavedRegs32EHRet : CalleeSavedRegs32Bit);
}
}
const TargetRegisterClass* const*
X86RegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
+ bool callsEHReturn = false;
+
+ if (MF) {
+ const MachineFrameInfo *MFI = MF->getFrameInfo();
+ const MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
+ callsEHReturn = (MMI ? MMI->callsEHReturn() : false);
+ }
+
static const TargetRegisterClass * const CalleeSavedRegClasses32Bit[] = {
&X86::GR32RegClass, &X86::GR32RegClass,
&X86::GR32RegClass, &X86::GR32RegClass, 0
&X86::GR64RegClass, &X86::GR64RegClass,
&X86::GR64RegClass, &X86::GR64RegClass, 0
};
+ static const TargetRegisterClass * const CalleeSavedRegClasses64EHRet[] = {
+ &X86::GR64RegClass, &X86::GR64RegClass,
+ &X86::GR64RegClass, &X86::GR64RegClass,
+ &X86::GR64RegClass, &X86::GR64RegClass,
+ &X86::GR64RegClass, &X86::GR64RegClass, 0
+ };
+ static const TargetRegisterClass * const CalleeSavedRegClassesWin64[] = {
+ &X86::GR64RegClass, &X86::GR64RegClass,
+ &X86::GR64RegClass, &X86::GR64RegClass,
+ &X86::GR64RegClass, &X86::GR64RegClass,
+ &X86::GR64RegClass, &X86::GR64RegClass,
+ &X86::VR128RegClass, &X86::VR128RegClass,
+ &X86::VR128RegClass, &X86::VR128RegClass,
+ &X86::VR128RegClass, &X86::VR128RegClass,
+ &X86::VR128RegClass, &X86::VR128RegClass,
+ &X86::VR128RegClass, &X86::VR128RegClass, 0
+ };
- if (Is64Bit)
- return CalleeSavedRegClasses64Bit;
- else {
- if (MF) {
- MachineFrameInfo *MFI = MF->getFrameInfo();
- MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
- if (MMI && MMI->callsEHReturn())
- return CalleeSavedRegClasses32EHRet;
- }
- return CalleeSavedRegClasses32Bit;
+ if (Is64Bit) {
+ if (IsWin64)
+ return CalleeSavedRegClassesWin64;
+ else
+ return (callsEHReturn ?
+ CalleeSavedRegClasses64EHRet : CalleeSavedRegClasses64Bit);
+ } else {
+ return (callsEHReturn ?
+ CalleeSavedRegClasses32EHRet : CalleeSavedRegClasses32Bit);
}
-
}
BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
BitVector Reserved(getNumRegs());
+ // Set the stack-pointer register and its aliases as reserved.
Reserved.set(X86::RSP);
Reserved.set(X86::ESP);
Reserved.set(X86::SP);
Reserved.set(X86::SPL);
+ // Set the frame-pointer register and its aliases as reserved if needed.
if (hasFP(MF)) {
Reserved.set(X86::RBP);
Reserved.set(X86::EBP);
Reserved.set(X86::BP);
Reserved.set(X86::BPL);
}
+ // Mark the x87 stack registers as reserved, since they don't
+ // behave normally with respect to liveness. We don't fully
+ // model the effects of x87 stack pushes and pops after
+ // stackification.
+ Reserved.set(X86::ST0);
+ Reserved.set(X86::ST1);
+ Reserved.set(X86::ST2);
+ Reserved.set(X86::ST3);
+ Reserved.set(X86::ST4);
+ Reserved.set(X86::ST5);
+ Reserved.set(X86::ST6);
+ Reserved.set(X86::ST7);
return Reserved;
}
// Stack Frame Processing methods
//===----------------------------------------------------------------------===//
+static unsigned calculateMaxStackAlignment(const MachineFrameInfo *FFI) {
+ unsigned MaxAlign = 0;
+ for (int i = FFI->getObjectIndexBegin(),
+ e = FFI->getObjectIndexEnd(); i != e; ++i) {
+ if (FFI->isDeadObjectIndex(i))
+ continue;
+ unsigned Align = FFI->getObjectAlignment(i);
+ MaxAlign = std::max(MaxAlign, Align);
+ }
+
+ return MaxAlign;
+}
+
// hasFP - Return true if the specified function should have a dedicated frame
// pointer register. This is true if the function has variable sized allocas or
// if frame pointer elimination is disabled.
//
bool X86RegisterInfo::hasFP(const MachineFunction &MF) const {
- MachineFrameInfo *MFI = MF.getFrameInfo();
- MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ const MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
- return (NoFramePointerElim ||
+ return (NoFramePointerElim ||
+ needsStackRealignment(MF) ||
MFI->hasVarSizedObjects() ||
+ MFI->isFrameAddressTaken() ||
MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
(MMI && MMI->callsUnwindInit()));
}
+bool X86RegisterInfo::needsStackRealignment(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+
+ // FIXME: Currently we don't support stack realignment for functions with
+ // variable-sized allocas
+ return (RealignStack &&
+ (MFI->getMaxAlignment() > StackAlign &&
+ !MFI->hasVarSizedObjects()));
+}
+
bool X86RegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {
return !MF.getFrameInfo()->hasVarSizedObjects();
}
+int
+X86RegisterInfo::getFrameIndexOffset(MachineFunction &MF, int FI) const {
+ int Offset = MF.getFrameInfo()->getObjectOffset(FI) + SlotSize;
+ uint64_t StackSize = MF.getFrameInfo()->getStackSize();
+
+ if (needsStackRealignment(MF)) {
+ if (FI < 0)
+ // Skip the saved EBP
+ Offset += SlotSize;
+ else {
+ unsigned Align = MF.getFrameInfo()->getObjectAlignment(FI);
+ assert( (-(Offset + StackSize)) % Align == 0);
+ Align = 0;
+ return Offset + StackSize;
+ }
+
+ // FIXME: Support tail calls
+ } else {
+ if (!hasFP(MF))
+ return Offset + StackSize;
+
+ // Skip the saved EBP
+ Offset += SlotSize;
+
+ // Skip the RETADDR move area
+ X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
+ int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
+ if (TailCallReturnAddrDelta < 0) Offset -= TailCallReturnAddrDelta;
+ }
+
+ return Offset;
+}
+
void X86RegisterInfo::
eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
MachineBasicBlock::iterator I) const {
Amount = (Amount+StackAlign-1)/StackAlign*StackAlign;
MachineInstr *New = 0;
- if (Old->getOpcode() == X86::ADJCALLSTACKDOWN) {
- New=BuildMI(TII.get(Is64Bit ? X86::SUB64ri32 : X86::SUB32ri), StackPtr)
- .addReg(StackPtr).addImm(Amount);
+ if (Old->getOpcode() == getCallFrameSetupOpcode()) {
+ New = BuildMI(MF, Old->getDebugLoc(),
+ TII.get(Is64Bit ? X86::SUB64ri32 : X86::SUB32ri),
+ StackPtr).addReg(StackPtr).addImm(Amount);
} else {
- assert(Old->getOpcode() == X86::ADJCALLSTACKUP);
+ assert(Old->getOpcode() == getCallFrameDestroyOpcode());
// factor out the amount the callee already popped.
uint64_t CalleeAmt = Old->getOperand(1).getImm();
Amount -= CalleeAmt;
unsigned Opc = (Amount < 128) ?
(Is64Bit ? X86::ADD64ri8 : X86::ADD32ri8) :
(Is64Bit ? X86::ADD64ri32 : X86::ADD32ri);
- New = BuildMI(TII.get(Opc), StackPtr).addReg(StackPtr).addImm(Amount);
+ New = BuildMI(MF, Old->getDebugLoc(), TII.get(Opc), StackPtr)
+ .addReg(StackPtr).addImm(Amount);
}
}
- // Replace the pseudo instruction with a new instruction...
- if (New) MBB.insert(I, New);
+ if (New) {
+ // The EFLAGS implicit def is dead.
+ New->getOperand(3).setIsDead();
+
+ // Replace the pseudo instruction with a new instruction...
+ MBB.insert(I, New);
+ }
}
- } else if (I->getOpcode() == X86::ADJCALLSTACKUP) {
+ } else if (I->getOpcode() == getCallFrameDestroyOpcode()) {
// 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 = (CalleeAmt < 128) ?
(Is64Bit ? X86::SUB64ri8 : X86::SUB32ri8) :
(Is64Bit ? X86::SUB64ri32 : X86::SUB32ri);
+ MachineInstr *Old = I;
MachineInstr *New =
- BuildMI(TII.get(Opc), StackPtr).addReg(StackPtr).addImm(CalleeAmt);
+ BuildMI(MF, Old->getDebugLoc(), TII.get(Opc),
+ StackPtr).addReg(StackPtr).addImm(CalleeAmt);
+ // The EFLAGS implicit def is dead.
+ New->getOperand(3).setIsDead();
+
MBB.insert(I, New);
}
}
unsigned i = 0;
MachineInstr &MI = *II;
MachineFunction &MF = *MI.getParent()->getParent();
- while (!MI.getOperand(i).isFrameIndex()) {
+ while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
int FrameIndex = MI.getOperand(i).getIndex();
+
+ unsigned BasePtr;
+ if (needsStackRealignment(MF))
+ BasePtr = (FrameIndex < 0 ? FramePtr : StackPtr);
+ else
+ BasePtr = (hasFP(MF) ? FramePtr : StackPtr);
+
// This must be part of a four operand memory reference. Replace the
// FrameIndex with base register with EBP. Add an offset to the offset.
- MI.getOperand(i).ChangeToRegister(hasFP(MF) ? FramePtr : StackPtr, false);
+ MI.getOperand(i).ChangeToRegister(BasePtr, false);
// Now add the frame object offset to the offset from EBP.
- int64_t Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
- MI.getOperand(i+3).getImm()+SlotSize;
-
- if (!hasFP(MF))
- Offset += MF.getFrameInfo()->getStackSize();
- else {
- Offset += SlotSize; // Skip the saved EBP
- // Skip the RETADDR move area
- X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
- if (TailCallReturnAddrDelta < 0) Offset -= TailCallReturnAddrDelta;
- }
+ if (MI.getOperand(i+3).isImm()) {
+ // Offset is a 32-bit integer.
+ int Offset = getFrameIndexOffset(MF, FrameIndex) +
+ (int)(MI.getOperand(i+3).getImm());
- MI.getOperand(i+3).ChangeToImmediate(Offset);
+ MI.getOperand(i+3).ChangeToImmediate(Offset);
+ } else {
+ // Offset is symbolic. This is extremely rare.
+ uint64_t Offset = getFrameIndexOffset(MF, FrameIndex) +
+ (uint64_t)MI.getOperand(i+3).getOffset();
+ MI.getOperand(i+3).setOffset(Offset);
+ }
+}
+
+void
+X86RegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+ RegScavenger *RS) const {
+ MachineFrameInfo *FFI = MF.getFrameInfo();
+
+ // Calculate and set max stack object alignment early, so we can decide
+ // whether we will need stack realignment (and thus FP).
+ unsigned MaxAlign = std::max(FFI->getMaxAlignment(),
+ calculateMaxStackAlignment(FFI));
+
+ FFI->setMaxAlignment(MaxAlign);
}
void
TailCallReturnAddrDelta);
assert(FrameIdx == MF.getFrameInfo()->getObjectIndexBegin() &&
"Slot for EBP register must be last in order to be found!");
+ FrameIdx = 0;
}
}
(Is64Bit ? X86::ADD64ri8 : X86::ADD32ri8) :
(Is64Bit ? X86::ADD64ri32 : X86::ADD32ri));
uint64_t Chunk = (1LL << 31) - 1;
+ DebugLoc DL = (MBBI != MBB.end() ? MBBI->getDebugLoc() :
+ DebugLoc::getUnknownLoc());
while (Offset) {
uint64_t ThisVal = (Offset > Chunk) ? Chunk : Offset;
- BuildMI(MBB, MBBI, TII.get(Opc), StackPtr).addReg(StackPtr).addImm(ThisVal);
+ MachineInstr *MI =
+ BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
+ .addReg(StackPtr).addImm(ThisVal);
+ // The EFLAGS implicit def is dead.
+ MI->getOperand(3).setIsDead();
Offset -= ThisVal;
}
}
void mergeSPUpdatesUp(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
unsigned StackPtr, uint64_t *NumBytes = NULL) {
if (MBBI == MBB.begin()) return;
-
+
MachineBasicBlock::iterator PI = prior(MBBI);
unsigned Opc = PI->getOpcode();
if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
MachineBasicBlock::iterator &MBBI,
unsigned StackPtr, uint64_t *NumBytes = NULL) {
return;
-
+
if (MBBI == MBB.end()) return;
-
+
MachineBasicBlock::iterator NI = next(MBBI);
if (NI == MBB.end()) return;
-
+
unsigned Opc = NI->getOpcode();
if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
}
/// mergeSPUpdates - Checks the instruction before/after the passed
-/// instruction. If it is an ADD/SUB instruction it is deleted
+/// instruction. If it is an ADD/SUB instruction it is deleted
/// argument and the stack adjustment is returned as a positive value for ADD
-/// and a negative for SUB.
+/// and a negative for SUB.
static int mergeSPUpdates(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI,
- unsigned StackPtr,
+ unsigned StackPtr,
bool doMergeWithPrevious) {
if ((doMergeWithPrevious && MBBI == MBB.begin()) ||
Offset -= PI->getOperand(2).getImm();
MBB.erase(PI);
if (!doMergeWithPrevious) MBBI = NI;
- }
+ }
return Offset;
}
+void X86RegisterInfo::emitFrameMoves(MachineFunction &MF,
+ unsigned FrameLabelId,
+ unsigned ReadyLabelId) const {
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
+ if (!MMI)
+ return;
+
+ uint64_t StackSize = MFI->getStackSize();
+ std::vector<MachineMove> &Moves = MMI->getFrameMoves();
+ const TargetData *TD = MF.getTarget().getTargetData();
+
+ // Calculate amount of bytes used for return address storing
+ int stackGrowth =
+ (MF.getTarget().getFrameInfo()->getStackGrowthDirection() ==
+ TargetFrameInfo::StackGrowsUp ?
+ TD->getPointerSize() : -TD->getPointerSize());
+
+ if (StackSize) {
+ // Show update of SP.
+ if (hasFP(MF)) {
+ // Adjust SP
+ MachineLocation SPDst(MachineLocation::VirtualFP);
+ MachineLocation SPSrc(MachineLocation::VirtualFP, 2*stackGrowth);
+ Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
+ } else {
+ MachineLocation SPDst(MachineLocation::VirtualFP);
+ MachineLocation SPSrc(MachineLocation::VirtualFP,
+ -StackSize+stackGrowth);
+ Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
+ }
+ } else {
+ //FIXME: Verify & implement for FP
+ MachineLocation SPDst(StackPtr);
+ MachineLocation SPSrc(StackPtr, stackGrowth);
+ Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
+ }
+
+ // Add callee saved registers to move list.
+ const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+
+ // 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 (minumum due to stack growth)
+ int64_t MaxOffset = 0;
+ for (unsigned I = 0, E = CSI.size(); I!=E; ++I)
+ MaxOffset = std::min(MaxOffset,
+ MFI->getObjectOffset(CSI[I].getFrameIdx()));
+
+ // Calculate offsets
+ int64_t saveAreaOffset = (hasFP(MF) ? 3 : 2)*stackGrowth;
+ for (unsigned I = 0, E = CSI.size(); I!=E; ++I) {
+ int64_t Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
+ unsigned Reg = CSI[I].getReg();
+ Offset = (MaxOffset-Offset+saveAreaOffset);
+ MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
+ MachineLocation CSSrc(Reg);
+ Moves.push_back(MachineMove(FrameLabelId, CSDst, CSSrc));
+ }
+
+ if (hasFP(MF)) {
+ // Save FP
+ MachineLocation FPDst(MachineLocation::VirtualFP, 2*stackGrowth);
+ MachineLocation FPSrc(FramePtr);
+ Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
+ }
+
+ MachineLocation FPDst(hasFP(MF) ? FramePtr : StackPtr);
+ MachineLocation FPSrc(MachineLocation::VirtualFP);
+ Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
+}
+
+
void X86RegisterInfo::emitPrologue(MachineFunction &MF) const {
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineFrameInfo *MFI = MF.getFrameInfo();
MachineModuleInfo *MMI = MFI->getMachineModuleInfo();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
MachineBasicBlock::iterator MBBI = MBB.begin();
-
+ bool needsFrameMoves = (MMI && MMI->hasDebugInfo()) ||
+ !Fn->doesNotThrow() ||
+ UnwindTablesMandatory;
+ DebugLoc DL = (MBBI != MBB.end() ? MBBI->getDebugLoc() :
+ DebugLoc::getUnknownLoc());
+
// Prepare for frame info.
unsigned FrameLabelId = 0;
-
+
// Get the number of bytes to allocate from the FrameInfo.
uint64_t StackSize = MFI->getStackSize();
+
+ // Get desired stack alignment
+ uint64_t MaxAlign = MFI->getMaxAlignment();
+
// Add RETADDR move area to callee saved frame size.
int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
- if (TailCallReturnAddrDelta < 0)
+ if (TailCallReturnAddrDelta < 0)
X86FI->setCalleeSavedFrameSize(
X86FI->getCalleeSavedFrameSize() +(-TailCallReturnAddrDelta));
- uint64_t NumBytes = StackSize - X86FI->getCalleeSavedFrameSize();
-
- // Skip over the labels which mark the beginning of the function.
- if (MMI && MMI->needsFrameInfo()) {
- unsigned NumLabels = 0;
- while (NumLabels <= 1 &&
- MBBI != MBB.end() && MBBI->getOpcode() == X86::LABEL) {
- ++NumLabels;
- ++MBBI;
- }
+
+ // 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).
+ if (Is64Bit && !DisableRedZone &&
+ !needsStackRealignment(MF) &&
+ !MFI->hasVarSizedObjects() && // No dynamic alloca.
+ !MFI->hasCalls()) { // No calls.
+ uint64_t MinSize = X86FI->getCalleeSavedFrameSize();
+ if (hasFP(MF)) MinSize += SlotSize;
+ StackSize = std::max(MinSize,
+ StackSize > 128 ? StackSize - 128 : 0);
+ MFI->setStackSize(StackSize);
}
// Insert stack pointer adjustment for later moving of return addr. Only
// applies to tail call optimized functions where the callee argument stack
// size is bigger than the callers.
if (TailCallReturnAddrDelta < 0) {
- BuildMI(MBB, MBBI, TII.get(Is64Bit? X86::SUB64ri32 : X86::SUB32ri),
- StackPtr).addReg(StackPtr).addImm(-TailCallReturnAddrDelta);
+ MachineInstr *MI =
+ BuildMI(MBB, MBBI, DL, TII.get(Is64Bit? X86::SUB64ri32 : X86::SUB32ri),
+ StackPtr).addReg(StackPtr).addImm(-TailCallReturnAddrDelta);
+ // The EFLAGS implicit def is dead.
+ MI->getOperand(3).setIsDead();
}
+ uint64_t NumBytes = 0;
if (hasFP(MF)) {
+ // Calculate required stack adjustment
+ uint64_t FrameSize = StackSize - SlotSize;
+ if (needsStackRealignment(MF))
+ FrameSize = (FrameSize + MaxAlign - 1)/MaxAlign*MaxAlign;
+
+ NumBytes = FrameSize - X86FI->getCalleeSavedFrameSize();
+
// Get the offset of the stack slot for the EBP register... which is
// guaranteed to be the last slot by processFunctionBeforeFrameFinalized.
// Update the frame offset adjustment.
- MFI->setOffsetAdjustment(SlotSize-NumBytes);
+ MFI->setOffsetAdjustment(-NumBytes);
// Save EBP into the appropriate stack slot...
- BuildMI(MBB, MBBI, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
- .addReg(FramePtr);
- NumBytes -= SlotSize;
+ BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
+ .addReg(FramePtr, /*isDef=*/false, /*isImp=*/false, /*isKill=*/true);
- if (MMI && MMI->needsFrameInfo()) {
+ if (needsFrameMoves) {
// Mark effective beginning of when frame pointer becomes valid.
FrameLabelId = MMI->NextLabelID();
- BuildMI(MBB, MBBI, TII.get(X86::LABEL)).addImm(FrameLabelId);
+ BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(FrameLabelId);
}
// Update EBP with the new base value...
- BuildMI(MBB, MBBI, TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), FramePtr)
- .addReg(StackPtr);
+ BuildMI(MBB, MBBI, DL,
+ TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), FramePtr)
+ .addReg(StackPtr);
+
+ // Mark the FramePtr as live-in in every block except the entry.
+ for (MachineFunction::iterator I = next(MF.begin()), E = MF.end();
+ I != E; ++I)
+ I->addLiveIn(FramePtr);
+
+ // Realign stack
+ if (needsStackRealignment(MF)) {
+ MachineInstr *MI =
+ BuildMI(MBB, MBBI, DL,
+ TII.get(Is64Bit ? X86::AND64ri32 : X86::AND32ri),
+ StackPtr).addReg(StackPtr).addImm(-MaxAlign);
+ // The EFLAGS implicit def is dead.
+ MI->getOperand(3).setIsDead();
+ }
+ } else {
+ NumBytes = StackSize - X86FI->getCalleeSavedFrameSize();
}
-
+
unsigned ReadyLabelId = 0;
- if (MMI && MMI->needsFrameInfo()) {
+ if (needsFrameMoves) {
// Mark effective beginning of when frame pointer is ready.
ReadyLabelId = MMI->NextLabelID();
- BuildMI(MBB, MBBI, TII.get(X86::LABEL)).addImm(ReadyLabelId);
+ BuildMI(MBB, MBBI, DL, TII.get(X86::DBG_LABEL)).addImm(ReadyLabelId);
}
// Skip the callee-saved push instructions.
MBBI->getOpcode() == X86::PUSH64r))
++MBBI;
+ if (MBBI != MBB.end())
+ DL = MBBI->getDebugLoc();
+
if (NumBytes) { // adjust stack pointer: ESP -= numbytes
if (NumBytes >= 4096 && Subtarget->isTargetCygMing()) {
// Check, whether EAX is livein for this function
Reg == X86::AH || Reg == X86::AL);
}
- // Function prologue calls _alloca to probe the stack when allocating
- // more than 4k bytes in one go. Touching the stack at 4K increments is
+ // Function prologue calls _alloca to probe the stack when allocating
+ // more than 4k bytes in one go. 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 (!isEAXAlive) {
- BuildMI(MBB, MBBI, TII.get(X86::MOV32ri), X86::EAX).addImm(NumBytes);
- BuildMI(MBB, MBBI, TII.get(X86::CALLpcrel32))
+ BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
+ .addImm(NumBytes);
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32))
.addExternalSymbol("_alloca");
} else {
// Save EAX
- BuildMI(MBB, MBBI, TII.get(X86::PUSH32r), X86::EAX);
+ BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
+ .addReg(X86::EAX, /*isDef=*/false, /*isImp=*/false, /*isKill=*/true);
// Allocate NumBytes-4 bytes on stack. We'll also use 4 already
// allocated bytes for EAX.
- BuildMI(MBB, MBBI, TII.get(X86::MOV32ri), X86::EAX).addImm(NumBytes-4);
- BuildMI(MBB, MBBI, TII.get(X86::CALLpcrel32))
+ BuildMI(MBB, MBBI, DL,
+ TII.get(X86::MOV32ri), X86::EAX).addImm(NumBytes-4);
+ BuildMI(MBB, MBBI, DL, TII.get(X86::CALLpcrel32))
.addExternalSymbol("_alloca");
// Restore EAX
- MachineInstr *MI = addRegOffset(BuildMI(TII.get(X86::MOV32rm),X86::EAX),
- StackPtr, NumBytes-4);
+ MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),
+ X86::EAX),
+ StackPtr, false, NumBytes-4);
MBB.insert(MBBI, MI);
}
} else {
// If there is an ADD32ri or SUB32ri of ESP immediately after this
// instruction, merge the two instructions.
mergeSPUpdatesDown(MBB, MBBI, StackPtr, &NumBytes);
-
+
if (NumBytes)
emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit, TII);
}
}
- if (MMI && MMI->needsFrameInfo()) {
- std::vector<MachineMove> &Moves = MMI->getFrameMoves();
- const TargetData *TD = MF.getTarget().getTargetData();
-
- // Calculate amount of bytes used for return address storing
- int stackGrowth =
- (MF.getTarget().getFrameInfo()->getStackGrowthDirection() ==
- TargetFrameInfo::StackGrowsUp ?
- TD->getPointerSize() : -TD->getPointerSize());
-
- if (StackSize) {
- // Show update of SP.
- if (hasFP(MF)) {
- // Adjust SP
- MachineLocation SPDst(MachineLocation::VirtualFP);
- MachineLocation SPSrc(MachineLocation::VirtualFP, 2*stackGrowth);
- Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
- } else {
- MachineLocation SPDst(MachineLocation::VirtualFP);
- MachineLocation SPSrc(MachineLocation::VirtualFP,
- -StackSize+stackGrowth);
- Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
- }
- } else {
- //FIXME: Verify & implement for FP
- MachineLocation SPDst(StackPtr);
- MachineLocation SPSrc(StackPtr, stackGrowth);
- Moves.push_back(MachineMove(FrameLabelId, SPDst, SPSrc));
- }
-
- // Add callee saved registers to move list.
- const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
-
- // 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 (minumum due to stack growth)
- int64_t MaxOffset = 0;
- for (unsigned I = 0, E = CSI.size(); I!=E; ++I)
- MaxOffset = std::min(MaxOffset,
- MFI->getObjectOffset(CSI[I].getFrameIdx()));
-
- // Calculate offsets
- int64_t saveAreaOffset = (hasFP(MF) ? 3 : 2)*stackGrowth;
- for (unsigned I = 0, E = CSI.size(); I!=E; ++I) {
- int64_t Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
- unsigned Reg = CSI[I].getReg();
- Offset = (MaxOffset-Offset+saveAreaOffset);
- MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
- MachineLocation CSSrc(Reg);
- Moves.push_back(MachineMove(FrameLabelId, CSDst, CSSrc));
- }
-
- if (hasFP(MF)) {
- // Save FP
- MachineLocation FPDst(MachineLocation::VirtualFP, 2*stackGrowth);
- MachineLocation FPSrc(FramePtr);
- Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
- }
-
- MachineLocation FPDst(hasFP(MF) ? FramePtr : StackPtr);
- MachineLocation FPSrc(MachineLocation::VirtualFP);
- Moves.push_back(MachineMove(ReadyLabelId, FPDst, FPSrc));
- }
-
- // If it's main() on Cygwin\Mingw32 we should align stack as well
- if (Fn->hasExternalLinkage() && Fn->getName() == "main" &&
- Subtarget->isTargetCygMing()) {
- BuildMI(MBB, MBBI, TII.get(X86::AND32ri), X86::ESP)
- .addReg(X86::ESP).addImm(-StackAlign);
-
- // Probe the stack
- BuildMI(MBB, MBBI, TII.get(X86::MOV32ri), X86::EAX).addImm(StackAlign);
- BuildMI(MBB, MBBI, TII.get(X86::CALLpcrel32)).addExternalSymbol("_alloca");
- }
+ if (needsFrameMoves)
+ emitFrameMoves(MF, FrameLabelId, ReadyLabelId);
}
void X86RegisterInfo::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
- const Function* Fn = MF.getFunction();
X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- const X86Subtarget* Subtarget = &MF.getTarget().getSubtarget<X86Subtarget>();
MachineBasicBlock::iterator MBBI = prior(MBB.end());
unsigned RetOpcode = MBBI->getOpcode();
+ DebugLoc DL = MBBI->getDebugLoc();
switch (RetOpcode) {
case X86::RET:
case X86::TCRETURNri64:
case X86::TCRETURNdi64:
case X86::EH_RETURN:
+ case X86::EH_RETURN64:
case X86::TAILJMPd:
case X86::TAILJMPr:
case X86::TAILJMPm: break; // These are ok
// Get the number of bytes to allocate from the FrameInfo
uint64_t StackSize = MFI->getStackSize();
+ uint64_t MaxAlign = MFI->getMaxAlignment();
unsigned CSSize = X86FI->getCalleeSavedFrameSize();
- uint64_t NumBytes = StackSize - CSSize;
+ uint64_t NumBytes = 0;
if (hasFP(MF)) {
+ // Calculate required stack adjustment
+ uint64_t FrameSize = StackSize - SlotSize;
+ if (needsStackRealignment(MF))
+ FrameSize = (FrameSize + MaxAlign - 1)/MaxAlign*MaxAlign;
+
+ NumBytes = FrameSize - CSSize;
+
// pop EBP.
- BuildMI(MBB, MBBI, TII.get(Is64Bit ? X86::POP64r : X86::POP32r), FramePtr);
- NumBytes -= SlotSize;
+ BuildMI(MBB, MBBI, DL,
+ TII.get(Is64Bit ? X86::POP64r : X86::POP32r), FramePtr);
+ } else {
+ NumBytes = StackSize - CSSize;
}
// Skip the callee-saved pop instructions.
+ MachineBasicBlock::iterator LastCSPop = MBBI;
while (MBBI != MBB.begin()) {
MachineBasicBlock::iterator PI = prior(MBBI);
unsigned Opc = PI->getOpcode();
--MBBI;
}
+ DL = MBBI->getDebugLoc();
+
// If there is an ADD32ri or SUB32ri of ESP immediately before this
// instruction, merge the two instructions.
if (NumBytes || MFI->hasVarSizedObjects())
mergeSPUpdatesUp(MBB, MBBI, StackPtr, &NumBytes);
// If dynamic alloca is used, then reset esp to point to the last callee-saved
- // slot before popping them off! Also, if it's main() on Cygwin/Mingw32 we
- // aligned stack in the prologue, - revert stack changes back. Note: we're
- // assuming, that frame pointer was forced for main()
- if (MFI->hasVarSizedObjects() ||
- (Fn->hasExternalLinkage() && Fn->getName() == "main" &&
- Subtarget->isTargetCygMing())) {
- unsigned Opc = Is64Bit ? X86::LEA64r : X86::LEA32r;
+ // slot before popping them off! Same applies for the case, when stack was
+ // realigned
+ if (needsStackRealignment(MF)) {
+ // We cannot use LEA here, because stack pointer was realigned. We need to
+ // deallocate local frame back
if (CSSize) {
- MachineInstr *MI = addRegOffset(BuildMI(TII.get(Opc), StackPtr),
- FramePtr, -CSSize);
+ emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII);
+ MBBI = prior(LastCSPop);
+ }
+
+ BuildMI(MBB, MBBI, DL,
+ TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),
+ StackPtr).addReg(FramePtr);
+ } else if (MFI->hasVarSizedObjects()) {
+ if (CSSize) {
+ unsigned Opc = Is64Bit ? X86::LEA64r : X86::LEA32r;
+ MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(Opc), StackPtr),
+ FramePtr, false, -CSSize);
MBB.insert(MBBI, MI);
} else
- BuildMI(MBB, MBBI, TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),StackPtr).
- addReg(FramePtr);
+ BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),
+ StackPtr).addReg(FramePtr);
- NumBytes = 0;
+ } else {
+ // adjust stack pointer back: ESP += numbytes
+ if (NumBytes)
+ emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII);
}
- // adjust stack pointer back: ESP += numbytes
- if (NumBytes)
- emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII);
-
// We're returning from function via eh_return.
- if (RetOpcode == X86::EH_RETURN) {
+ if (RetOpcode == X86::EH_RETURN || RetOpcode == X86::EH_RETURN64) {
MBBI = prior(MBB.end());
MachineOperand &DestAddr = MBBI->getOperand(0);
- assert(DestAddr.isRegister() && "Offset should be in register!");
- BuildMI(MBB, MBBI, TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),StackPtr).
- addReg(DestAddr.getReg());
+ assert(DestAddr.isReg() && "Offset should be in register!");
+ BuildMI(MBB, MBBI, DL,
+ TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),
+ StackPtr).addReg(DestAddr.getReg());
// Tail call return: adjust the stack pointer and jump to callee
} else if (RetOpcode == X86::TCRETURNri || RetOpcode == X86::TCRETURNdi ||
RetOpcode== X86::TCRETURNri64 || RetOpcode == X86::TCRETURNdi64) {
MBBI = prior(MBB.end());
MachineOperand &JumpTarget = MBBI->getOperand(0);
MachineOperand &StackAdjust = MBBI->getOperand(1);
- assert( StackAdjust.isImmediate() && "Expecting immediate value.");
-
+ assert(StackAdjust.isImm() && "Expecting immediate value.");
+
// Adjust stack pointer.
int StackAdj = StackAdjust.getImm();
int MaxTCDelta = X86FI->getTCReturnAddrDelta();
// Incoporate the retaddr area.
Offset = StackAdj-MaxTCDelta;
assert(Offset >= 0 && "Offset should never be negative");
+
if (Offset) {
// Check for possible merge with preceeding ADD instruction.
Offset += mergeSPUpdates(MBB, MBBI, StackPtr, true);
emitSPUpdate(MBB, MBBI, StackPtr, Offset, Is64Bit, TII);
- }
+ }
+
// Jump to label or value in register.
if (RetOpcode == X86::TCRETURNdi|| RetOpcode == X86::TCRETURNdi64)
- BuildMI(MBB, MBBI, TII.get(X86::TAILJMPd)).
+ BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPd)).
addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset());
- else if (RetOpcode== X86::TCRETURNri64) {
- BuildMI(MBB, MBBI, TII.get(X86::TAILJMPr64), JumpTarget.getReg());
- } else
- BuildMI(MBB, MBBI, TII.get(X86::TAILJMPr), JumpTarget.getReg());
+ else if (RetOpcode== X86::TCRETURNri64)
+ BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPr64), JumpTarget.getReg());
+ else
+ BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPr), JumpTarget.getReg());
+
// Delete the pseudo instruction TCRETURN.
MBB.erase(MBBI);
- } else if ((RetOpcode == X86::RET || RetOpcode == X86::RETI) &&
+ } else if ((RetOpcode == X86::RET || RetOpcode == X86::RETI) &&
(X86FI->getTCReturnAddrDelta() < 0)) {
// Add the return addr area delta back since we are not tail calling.
int delta = -1*X86FI->getTCReturnAddrDelta();
return hasFP(MF) ? FramePtr : StackPtr;
}
-int
-X86RegisterInfo::getFrameIndexOffset(MachineFunction &MF, unsigned FI) const {
- int Offset = MF.getFrameInfo()->getObjectOffset(FI) + SlotSize;
- if (!hasFP(MF))
- return Offset + MF.getFrameInfo()->getStackSize();
-
- Offset += SlotSize; // Skip the saved EBP
- // Skip the RETADDR move area
- X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
- if (TailCallReturnAddrDelta < 0) Offset -= TailCallReturnAddrDelta;
- return Offset;
-}
-
void X86RegisterInfo::getInitialFrameState(std::vector<MachineMove> &Moves)
const {
// Calculate amount of bytes used for return address storing
}
namespace llvm {
-unsigned getX86SubSuperRegister(unsigned Reg, MVT::ValueType VT, bool High) {
- switch (VT) {
+unsigned getX86SubSuperRegister(unsigned Reg, MVT VT, bool High) {
+ switch (VT.getSimpleVT()) {
default: return Reg;
case MVT::i8:
if (High) {
#include "X86GenRegisterInfo.inc"
+namespace {
+ struct VISIBILITY_HIDDEN MSAC : public MachineFunctionPass {
+ static char ID;
+ MSAC() : MachineFunctionPass(&ID) {}
+
+ virtual bool runOnMachineFunction(MachineFunction &MF) {
+ MachineFrameInfo *FFI = MF.getFrameInfo();
+ MachineRegisterInfo &RI = MF.getRegInfo();
+
+ // Calculate max stack alignment of all already allocated stack objects.
+ unsigned MaxAlign = calculateMaxStackAlignment(FFI);
+
+ // Be over-conservative: scan over all vreg defs and find, whether vector
+ // registers are used. If yes - there is probability, that vector register
+ // will be spilled and thus stack needs to be aligned properly.
+ for (unsigned RegNum = TargetRegisterInfo::FirstVirtualRegister;
+ RegNum < RI.getLastVirtReg(); ++RegNum)
+ MaxAlign = std::max(MaxAlign, RI.getRegClass(RegNum)->getAlignment());
+
+ FFI->setMaxAlignment(MaxAlign);
+
+ return false;
+ }
+
+ virtual const char *getPassName() const {
+ return "X86 Maximal Stack Alignment Calculator";
+ }
+ };
+
+ char MSAC::ID = 0;
+}
+
+FunctionPass*
+llvm::createX86MaxStackAlignmentCalculatorPass() { return new MSAC(); }
projects / oota-llvm.git / blobdiff