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authorAnton Korobeynikov <asl@math.spbu.ru>2011-01-10 12:39:04 +0000
committerAnton Korobeynikov <asl@math.spbu.ru>2011-01-10 12:39:04 +0000
commit16c29b5f285f375be53dabaa73e3e91107485fe4 (patch)
treedf7ee2e7da3560e6169260f744977299af674494 /lib/Target/X86/X86FrameInfo.cpp
parentbadbd2fde9b8debd6265e8ece511fb01123d1d5f (diff)
Rename TargetFrameInfo into TargetFrameLowering. Also, put couple of FIXMEs and fixes here and there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123170 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86FrameInfo.cpp')
-rw-r--r--lib/Target/X86/X86FrameInfo.cpp999
1 files changed, 0 insertions, 999 deletions
diff --git a/lib/Target/X86/X86FrameInfo.cpp b/lib/Target/X86/X86FrameInfo.cpp
deleted file mode 100644
index 5a8d9768f8..0000000000
--- a/lib/Target/X86/X86FrameInfo.cpp
+++ /dev/null
@@ -1,999 +0,0 @@
-//=======- X86FrameInfo.cpp - X86 Frame Information ------------*- C++ -*-====//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains the X86 implementation of TargetFrameInfo class.
-//
-//===----------------------------------------------------------------------===//
-
-#include "X86FrameInfo.h"
-#include "X86InstrBuilder.h"
-#include "X86InstrInfo.h"
-#include "X86MachineFunctionInfo.h"
-#include "X86TargetMachine.h"
-#include "llvm/Function.h"
-#include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineModuleInfo.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetOptions.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/ADT/SmallSet.h"
-
-using namespace llvm;
-
-// FIXME: completely move here.
-extern cl::opt<bool> ForceStackAlign;
-
-bool X86FrameInfo::hasReservedCallFrame(const MachineFunction &MF) const {
- return !MF.getFrameInfo()->hasVarSizedObjects();
-}
-
-/// hasFP - Return true if the specified function should have a dedicated frame
-/// pointer register. This is true if the function has variable sized allocas
-/// or if frame pointer elimination is disabled.
-bool X86FrameInfo::hasFP(const MachineFunction &MF) const {
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- const MachineModuleInfo &MMI = MF.getMMI();
- const TargetRegisterInfo *RI = TM.getRegisterInfo();
-
- return (DisableFramePointerElim(MF) ||
- RI->needsStackRealignment(MF) ||
- MFI->hasVarSizedObjects() ||
- MFI->isFrameAddressTaken() ||
- MF.getInfo<X86MachineFunctionInfo>()->getForceFramePointer() ||
- MMI.callsUnwindInit());
-}
-
-static unsigned getSUBriOpcode(unsigned is64Bit, int64_t Imm) {
- if (is64Bit) {
- if (isInt<8>(Imm))
- return X86::SUB64ri8;
- return X86::SUB64ri32;
- } else {
- if (isInt<8>(Imm))
- return X86::SUB32ri8;
- return X86::SUB32ri;
- }
-}
-
-static unsigned getADDriOpcode(unsigned is64Bit, int64_t Imm) {
- if (is64Bit) {
- if (isInt<8>(Imm))
- return X86::ADD64ri8;
- return X86::ADD64ri32;
- } else {
- if (isInt<8>(Imm))
- return X86::ADD32ri8;
- return X86::ADD32ri;
- }
-}
-
-/// findDeadCallerSavedReg - Return a caller-saved register that isn't live
-/// when it reaches the "return" instruction. We can then pop a stack object
-/// to this register without worry about clobbering it.
-static unsigned findDeadCallerSavedReg(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator &MBBI,
- const TargetRegisterInfo &TRI,
- bool Is64Bit) {
- const MachineFunction *MF = MBB.getParent();
- const Function *F = MF->getFunction();
- if (!F || MF->getMMI().callsEHReturn())
- return 0;
-
- static const unsigned CallerSavedRegs32Bit[] = {
- X86::EAX, X86::EDX, X86::ECX
- };
-
- static const unsigned CallerSavedRegs64Bit[] = {
- X86::RAX, X86::RDX, X86::RCX, X86::RSI, X86::RDI,
- X86::R8, X86::R9, X86::R10, X86::R11
- };
-
- unsigned Opc = MBBI->getOpcode();
- switch (Opc) {
- default: return 0;
- case X86::RET:
- case X86::RETI:
- case X86::TCRETURNdi:
- case X86::TCRETURNri:
- case X86::TCRETURNmi:
- case X86::TCRETURNdi64:
- case X86::TCRETURNri64:
- case X86::TCRETURNmi64:
- case X86::EH_RETURN:
- case X86::EH_RETURN64: {
- SmallSet<unsigned, 8> Uses;
- for (unsigned i = 0, e = MBBI->getNumOperands(); i != e; ++i) {
- MachineOperand &MO = MBBI->getOperand(i);
- if (!MO.isReg() || MO.isDef())
- continue;
- unsigned Reg = MO.getReg();
- if (!Reg)
- continue;
- for (const unsigned *AsI = TRI.getOverlaps(Reg); *AsI; ++AsI)
- Uses.insert(*AsI);
- }
-
- const unsigned *CS = Is64Bit ? CallerSavedRegs64Bit : CallerSavedRegs32Bit;
- for (; *CS; ++CS)
- if (!Uses.count(*CS))
- return *CS;
- }
- }
-
- return 0;
-}
-
-
-/// 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, const TargetInstrInfo &TII,
- const TargetRegisterInfo &TRI) {
- bool isSub = NumBytes < 0;
- uint64_t Offset = isSub ? -NumBytes : NumBytes;
- unsigned Opc = isSub ?
- getSUBriOpcode(Is64Bit, Offset) :
- getADDriOpcode(Is64Bit, 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)) {
- // Use push / pop instead.
- unsigned Reg = isSub
- ? (unsigned)(Is64Bit ? X86::RAX : X86::EAX)
- : findDeadCallerSavedReg(MBB, MBBI, TRI, Is64Bit);
- if (Reg) {
- Opc = isSub
- ? (Is64Bit ? X86::PUSH64r : X86::PUSH32r)
- : (Is64Bit ? X86::POP64r : X86::POP32r);
- BuildMI(MBB, MBBI, DL, TII.get(Opc))
- .addReg(Reg, getDefRegState(!isSub) | getUndefRegState(isSub));
- Offset -= ThisVal;
- continue;
- }
- }
-
- MachineInstr *MI =
- BuildMI(MBB, MBBI, DL, TII.get(Opc), StackPtr)
- .addReg(StackPtr)
- .addImm(ThisVal);
- MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
- Offset -= ThisVal;
- }
-}
-
-/// mergeSPUpdatesUp - Merge two stack-manipulating instructions upper iterator.
-static
-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 ||
- Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
- PI->getOperand(0).getReg() == StackPtr) {
- if (NumBytes)
- *NumBytes += PI->getOperand(2).getImm();
- MBB.erase(PI);
- } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
- Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
- PI->getOperand(0).getReg() == StackPtr) {
- if (NumBytes)
- *NumBytes -= PI->getOperand(2).getImm();
- MBB.erase(PI);
- }
-}
-
-/// 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 instruction it is deleted argument and the
-/// stack adjustment is returned as a positive value for ADD and a negative for
-/// SUB.
-static int mergeSPUpdates(MachineBasicBlock &MBB,
- 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);
- unsigned Opc = PI->getOpcode();
- int Offset = 0;
-
- if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
- Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
- PI->getOperand(0).getReg() == StackPtr){
- Offset += PI->getOperand(2).getImm();
- MBB.erase(PI);
- if (!doMergeWithPrevious) MBBI = NI;
- } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
- Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
- PI->getOperand(0).getReg() == StackPtr) {
- Offset -= PI->getOperand(2).getImm();
- MBB.erase(PI);
- if (!doMergeWithPrevious) MBBI = NI;
- }
-
- 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 X86FrameInfo::emitCalleeSavedFrameMoves(MachineFunction &MF,
- MCSymbol *Label,
- unsigned FramePtr) const {
- MachineFrameInfo *MFI = MF.getFrameInfo();
- MachineModuleInfo &MMI = MF.getMMI();
-
- // Add callee saved registers to move list.
- const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
- if (CSI.empty()) return;
-
- std::vector<MachineMove> &Moves = MMI.getFrameMoves();
- const TargetData *TD = TM.getTargetData();
- bool HasFP = hasFP(MF);
-
- // Calculate amount of bytes used for return address storing.
- int stackGrowth =
- (TM.getFrameInfo()->getStackGrowthDirection() ==
- TargetFrameInfo::StackGrowsUp ?
- TD->getPointerSize() : -TD->getPointerSize());
-
- // 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 (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);
- Moves.push_back(MachineMove(Label, CSDst, CSSrc));
- }
-}
-
-/// 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 X86FrameInfo::emitPrologue(MachineFunction &MF) const {
- MachineBasicBlock &MBB = MF.front(); // Prologue goes in entry BB.
- MachineBasicBlock::iterator MBBI = MBB.begin();
- MachineFrameInfo *MFI = MF.getFrameInfo();
- const Function *Fn = MF.getFunction();
- const X86RegisterInfo *RegInfo = TM.getRegisterInfo();
- const X86InstrInfo &TII = *TM.getInstrInfo();
- MachineModuleInfo &MMI = MF.getMMI();
- X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- bool needsFrameMoves = MMI.hasDebugInfo() ||
- !Fn->doesNotThrow() || UnwindTablesMandatory;
- uint64_t MaxAlign = MFI->getMaxAlignment(); // Desired stack alignment.
- uint64_t StackSize = MFI->getStackSize(); // Number of bytes to allocate.
- bool HasFP = hasFP(MF);
- bool Is64Bit = STI.is64Bit();
- bool IsWin64 = STI.isTargetWin64();
- unsigned StackAlign = getStackAlignment();
- unsigned SlotSize = RegInfo->getSlotSize();
- unsigned FramePtr = RegInfo->getFrameRegister(MF);
- unsigned StackPtr = RegInfo->getStackRegister();
-
- 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 < 0)
- X86FI->setCalleeSavedFrameSize(
- X86FI->getCalleeSavedFrameSize() - TailCallReturnAddrDelta);
-
- // 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 && !Fn->hasFnAttr(Attribute::NoRedZone) &&
- !RegInfo->needsStackRealignment(MF) &&
- !MFI->hasVarSizedObjects() && // No dynamic alloca.
- !MFI->adjustsStack() && // No calls.
- !IsWin64) { // Win64 has no Red Zone
- uint64_t MinSize = X86FI->getCalleeSavedFrameSize();
- if (HasFP) MinSize += SlotSize;
- StackSize = std::max(MinSize, StackSize > 128 ? StackSize - 128 : 0);
- MFI->setStackSize(StackSize);
- } else if (IsWin64) {
- // We need to always allocate 32 bytes as register spill area.
- // FIXME: We might reuse these 32 bytes for leaf functions.
- StackSize += 32;
- 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) {
- MachineInstr *MI =
- BuildMI(MBB, MBBI, DL,
- TII.get(getSUBriOpcode(Is64Bit, -TailCallReturnAddrDelta)),
- StackPtr)
- .addReg(StackPtr)
- .addImm(-TailCallReturnAddrDelta);
- MI->getOperand(3).setIsDead(); // The EFLAGS implicit def is dead.
- }
-
- // Mapping for machine moves:
- //
- // DST: VirtualFP AND
- // SRC: VirtualFP => DW_CFA_def_cfa_offset
- // ELSE => DW_CFA_def_cfa
- //
- // SRC: VirtualFP AND
- // DST: Register => DW_CFA_def_cfa_register
- //
- // ELSE
- // OFFSET < 0 => DW_CFA_offset_extended_sf
- // REG < 64 => DW_CFA_offset + Reg
- // ELSE => DW_CFA_offset_extended
-
- std::vector<MachineMove> &Moves = MMI.getFrameMoves();
- const TargetData *TD = MF.getTarget().getTargetData();
- uint64_t NumBytes = 0;
- int stackGrowth = -TD->getPointerSize();
-
- if (HasFP) {
- // Calculate required stack adjustment.
- uint64_t FrameSize = StackSize - SlotSize;
- if (RegInfo->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(-NumBytes);
-
- // Save EBP/RBP into the appropriate stack slot.
- BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::PUSH64r : X86::PUSH32r))
- .addReg(FramePtr, RegState::Kill);
-
- if (needsFrameMoves) {
- // 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);
- Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
- } else {
- // FIXME: Verify & implement for FP
- MachineLocation SPDst(StackPtr);
- MachineLocation SPSrc(StackPtr, stackGrowth);
- Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
- }
-
- // Change the rule for the FramePtr to be an "offset" rule.
- MachineLocation FPDst(MachineLocation::VirtualFP, 2 * stackGrowth);
- MachineLocation FPSrc(FramePtr);
- Moves.push_back(MachineMove(FrameLabel, FPDst, FPSrc));
- }
-
- // Update EBP with the new base value...
- BuildMI(MBB, MBBI, DL,
- TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), FramePtr)
- .addReg(StackPtr);
-
- 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);
-
- // Define the current CFA to use the EBP/RBP register.
- MachineLocation FPDst(FramePtr);
- MachineLocation FPSrc(MachineLocation::VirtualFP);
- Moves.push_back(MachineMove(FrameLabel, FPDst, FPSrc));
- }
-
- // 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);
-
- // Realign stack
- if (RegInfo->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();
- }
-
- // Skip the callee-saved push instructions.
- bool PushedRegs = false;
- int StackOffset = 2 * stackGrowth;
-
- while (MBBI != MBB.end() &&
- (MBBI->getOpcode() == X86::PUSH32r ||
- MBBI->getOpcode() == X86::PUSH64r)) {
- PushedRegs = true;
- ++MBBI;
-
- if (!HasFP && needsFrameMoves) {
- // 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);
- Moves.push_back(MachineMove(Label, SPDst, SPSrc));
- StackOffset += stackGrowth;
- }
- }
-
- DL = MBB.findDebugLoc(MBBI);
-
- // If there is an SUB32ri of ESP immediately before this instruction, merge
- // the two. This can be the case when tail call elimination is enabled and
- // the callee has more arguments then the caller.
- NumBytes -= mergeSPUpdates(MBB, MBBI, StackPtr, true);
-
- // 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
- // more than 4K bytes on the stack. Windows uses __chkstk and cygwin/mingw
- // uses __alloca. __alloca and the 32-bit version of __chkstk will probe the
- // stack and adjust the stack pointer in one go. The 64-bit version of
- // __chkstk is only responsible for probing the stack. The 64-bit prologue is
- // 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.isTargetCygMing() || STI.isTargetWin32())) {
- // Check whether EAX is livein for this function.
- bool isEAXAlive = isEAXLiveIn(MF);
-
- const char *StackProbeSymbol =
- STI.isTargetWindows() ? "_chkstk" : "_alloca";
- if (Is64Bit && STI.isTargetCygMing())
- StackProbeSymbol = "__chkstk";
- unsigned CallOp = Is64Bit ? X86::CALL64pcrel32 : X86::CALLpcrel32;
- if (!isEAXAlive) {
- BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
- .addImm(NumBytes);
- BuildMI(MBB, MBBI, DL, TII.get(CallOp))
- .addExternalSymbol(StackProbeSymbol)
- .addReg(StackPtr, RegState::Define | RegState::Implicit)
- .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
- } else {
- // Save EAX
- BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
- .addReg(X86::EAX, RegState::Kill);
-
- // Allocate NumBytes-4 bytes on stack. We'll also use 4 already
- // allocated bytes for EAX.
- BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
- .addImm(NumBytes - 4);
- BuildMI(MBB, MBBI, DL, TII.get(CallOp))
- .addExternalSymbol(StackProbeSymbol)
- .addReg(StackPtr, RegState::Define | RegState::Implicit)
- .addReg(X86::EFLAGS, RegState::Define | RegState::Implicit);
-
- // Restore EAX
- MachineInstr *MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm),
- X86::EAX),
- StackPtr, false, NumBytes - 4);
- MBB.insert(MBBI, MI);
- }
- } else if (NumBytes >= 4096 && STI.isTargetWin64()) {
- // Sanity check that EAX is not livein for this function. It should
- // should not be, so throw an assert.
- assert(!isEAXLiveIn(MF) && "EAX is livein in the Win64 case!");
-
- // 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::MOV32ri), X86::EAX)
- .addImm(NumBytes);
- BuildMI(MBB, MBBI, DL, TII.get(X86::WINCALL64pcrel32))
- .addExternalSymbol("__chkstk")
- .addReg(StackPtr, RegState::Define | RegState::Implicit);
- emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit,
- TII, *RegInfo);
- } else if (NumBytes)
- emitSPUpdate(MBB, MBBI, StackPtr, -(int64_t)NumBytes, Is64Bit,
- TII, *RegInfo);
-
- if ((NumBytes || PushedRegs) && needsFrameMoves) {
- // 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);
- Moves.push_back(MachineMove(Label, SPDst, SPSrc));
- } else {
- // FIXME: Verify & implement for FP
- MachineLocation SPDst(StackPtr);
- MachineLocation SPSrc(StackPtr, stackGrowth);
- Moves.push_back(MachineMove(Label, SPDst, SPSrc));
- }
- }
-
- // Emit DWARF info specifying the offsets of the callee-saved registers.
- if (PushedRegs)
- emitCalleeSavedFrameMoves(MF, Label, HasFP ? FramePtr : StackPtr);
- }
-}
-
-void X86FrameInfo::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();
- MachineBasicBlock::iterator MBBI = prior(MBB.end());
- unsigned RetOpcode = MBBI->getOpcode();
- DebugLoc DL = MBBI->getDebugLoc();
- bool Is64Bit = STI.is64Bit();
- unsigned StackAlign = getStackAlignment();
- unsigned SlotSize = RegInfo->getSlotSize();
- unsigned FramePtr = RegInfo->getFrameRegister(MF);
- unsigned StackPtr = RegInfo->getStackRegister();
-
- switch (RetOpcode) {
- default:
- llvm_unreachable("Can only insert epilog into returning blocks");
- case X86::RET:
- case X86::RETI:
- case X86::TCRETURNdi:
- case X86::TCRETURNri:
- case X86::TCRETURNmi:
- case X86::TCRETURNdi64:
- case X86::TCRETURNri64:
- case X86::TCRETURNmi64:
- case X86::EH_RETURN:
- case X86::EH_RETURN64:
- 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 = 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))
- FrameSize = (FrameSize + MaxAlign - 1)/MaxAlign*MaxAlign;
-
- NumBytes = FrameSize - CSSize;
-
- // Pop EBP.
- 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();
-
- if (Opc != X86::POP32r && Opc != X86::POP64r &&
- !PI->getDesc().isTerminator())
- break;
-
- --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! Same applies for the case, when stack was
- // realigned.
- if (RegInfo->needsStackRealignment(MF)) {
- // We cannot use LEA here, because stack pointer was realigned. We need to
- // deallocate local frame back.
- if (CSSize) {
- emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII, *RegInfo);
- 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, DL,
- TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr), StackPtr)
- .addReg(FramePtr);
- }
- } else if (NumBytes) {
- // Adjust stack pointer back: ESP += numbytes.
- emitSPUpdate(MBB, MBBI, StackPtr, NumBytes, Is64Bit, TII, *RegInfo);
- }
-
- // We're returning from function via eh_return.
- if (RetOpcode == X86::EH_RETURN || RetOpcode == X86::EH_RETURN64) {
- MBBI = prior(MBB.end());
- MachineOperand &DestAddr = MBBI->getOperand(0);
- assert(DestAddr.isReg() && "Offset should be in register!");
- BuildMI(MBB, MBBI, DL,
- TII.get(Is64Bit ? X86::MOV64rr : X86::MOV32rr),
- StackPtr).addReg(DestAddr.getReg());
- } else if (RetOpcode == X86::TCRETURNri || RetOpcode == X86::TCRETURNdi ||
- RetOpcode == X86::TCRETURNmi ||
- RetOpcode == X86::TCRETURNri64 || RetOpcode == X86::TCRETURNdi64 ||
- RetOpcode == X86::TCRETURNmi64) {
- bool isMem = RetOpcode == X86::TCRETURNmi || RetOpcode == X86::TCRETURNmi64;
- // Tail call return: adjust the stack pointer and jump to callee.
- MBBI = prior(MBB.end());
- MachineOperand &JumpTarget = MBBI->getOperand(0);
- MachineOperand &StackAdjust = MBBI->getOperand(isMem ? 5 : 1);
- assert(StackAdjust.isImm() && "Expecting immediate value.");
-
- // Adjust stack pointer.
- int StackAdj = StackAdjust.getImm();
- int MaxTCDelta = X86FI->getTCReturnAddrDelta();
- int Offset = 0;
- assert(MaxTCDelta <= 0 && "MaxTCDelta should never be positive");
-
- // 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, *RegInfo);
- }
-
- // Jump to label or value in register.
- if (RetOpcode == X86::TCRETURNdi || RetOpcode == X86::TCRETURNdi64) {
- MachineInstrBuilder MIB =
- BuildMI(MBB, MBBI, DL, TII.get((RetOpcode == X86::TCRETURNdi)
- ? X86::TAILJMPd : X86::TAILJMPd64));
- if (JumpTarget.isGlobal())
- MIB.addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
- JumpTarget.getTargetFlags());
- else {
- assert(JumpTarget.isSymbol());
- MIB.addExternalSymbol(JumpTarget.getSymbolName(),
- 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));
- 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);
- } else {
- BuildMI(MBB, MBBI, DL, TII.get(X86::TAILJMPr)).
- addReg(JumpTarget.getReg(), RegState::Kill);
- }
-
- MachineInstr *NewMI = prior(MBBI);
- for (unsigned i = 2, e = MBBI->getNumOperands(); i != e; ++i)
- NewMI->addOperand(MBBI->getOperand(i));
-
- // Delete the pseudo instruction TCRETURN.
- MBB.erase(MBBI);
- } 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();
- MBBI = prior(MBB.end());
-
- // Check for possible merge with preceeding ADD instruction.
- delta += mergeSPUpdates(MBB, MBBI, StackPtr, true);
- emitSPUpdate(MBB, MBBI, StackPtr, delta, Is64Bit, TII, *RegInfo);
- }
-}
-
-void
-X86FrameInfo::getInitialFrameState(std::vector<MachineMove> &Moves) const {
- // Calculate amount of bytes used for return address storing
- int stackGrowth = (STI.is64Bit() ? -8 : -4);
- const X86RegisterInfo *RI = TM.getRegisterInfo();
-
- // Initial state of the frame pointer is esp+stackGrowth.
- MachineLocation Dst(MachineLocation::VirtualFP);
- MachineLocation Src(RI->getStackRegister(), stackGrowth);
- Moves.push_back(MachineMove(0, Dst, Src));
-
- // Add return address to move list
- MachineLocation CSDst(RI->getStackRegister(), stackGrowth);
- MachineLocation CSSrc(RI->getRARegister());
- Moves.push_back(MachineMove(0, CSDst, CSSrc));
-}
-
-int X86FrameInfo::getFrameIndexOffset(const MachineFunction &MF, int FI) const {
- const X86RegisterInfo *RI =
- static_cast<const X86RegisterInfo*>(MF.getTarget().getRegisterInfo());
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- int Offset = MFI->getObjectOffset(FI) - getOffsetOfLocalArea();
- uint64_t StackSize = MFI->getStackSize();
-
- if (RI->needsStackRealignment(MF)) {
- if (FI < 0) {
- // Skip the saved EBP.
- Offset += RI->getSlotSize();
- } else {
- unsigned Align = MFI->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 += RI->getSlotSize();
-
- // Skip the RETADDR move area
- const X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
- int TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
- if (TailCallReturnAddrDelta < 0)
- Offset -= TailCallReturnAddrDelta;
- }
-
- return Offset;
-}
-
-bool X86FrameInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
- MachineBasicBlock::iterator MI,
- const std::vector<CalleeSavedInfo> &CSI,
- const TargetRegisterInfo *TRI) const {
- if (CSI.empty())
- return false;
-
- DebugLoc DL = MBB.findDebugLoc(MI);
-
- MachineFunction &MF = *MBB.getParent();
-
- bool isWin64 = STI.isTargetWin64();
- unsigned SlotSize = STI.is64Bit() ? 8 : 4;
- unsigned FPReg = TRI->getFrameRegister(MF);
- unsigned CalleeFrameSize = 0;
-
- const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
- X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
-
- unsigned Opc = STI.is64Bit() ? X86::PUSH64r : X86::PUSH32r;
- for (unsigned i = CSI.size(); i != 0; --i) {
- unsigned Reg = CSI[i-1].getReg();
- // 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;
- if (!X86::VR128RegClass.contains(Reg) && !isWin64) {
- CalleeFrameSize += SlotSize;
- BuildMI(MBB, MI, DL, TII.get(Opc)).addReg(Reg, R