diff options
Diffstat (limited to 'lib/Target/ARM/ARMInstrInfo.cpp')
-rw-r--r-- | lib/Target/ARM/ARMInstrInfo.cpp | 599 |
1 files changed, 306 insertions, 293 deletions
diff --git a/lib/Target/ARM/ARMInstrInfo.cpp b/lib/Target/ARM/ARMInstrInfo.cpp index 482867e6ec..443fdc742e 100644 --- a/lib/Target/ARM/ARMInstrInfo.cpp +++ b/lib/Target/ARM/ARMInstrInfo.cpp @@ -47,91 +47,6 @@ ARMInstrInfo::ARMInstrInfo(const ARMSubtarget &STI) : ARMBaseInstrInfo(STI), RI(*this, STI) { } -/// Return true if the instruction is a register to register move and -/// leave the source and dest operands in the passed parameters. -/// -bool ARMInstrInfo::isMoveInstr(const MachineInstr &MI, - unsigned &SrcReg, unsigned &DstReg, - unsigned& SrcSubIdx, unsigned& DstSubIdx) const { - SrcSubIdx = DstSubIdx = 0; // No sub-registers. - - unsigned oc = MI.getOpcode(); - switch (oc) { - default: - return false; - case ARM::FCPYS: - case ARM::FCPYD: - case ARM::VMOVD: - case ARM::VMOVQ: - SrcReg = MI.getOperand(1).getReg(); - DstReg = MI.getOperand(0).getReg(); - return true; - case ARM::MOVr: - assert(MI.getDesc().getNumOperands() >= 2 && - MI.getOperand(0).isReg() && - MI.getOperand(1).isReg() && - "Invalid ARM MOV instruction"); - SrcReg = MI.getOperand(1).getReg(); - DstReg = MI.getOperand(0).getReg(); - return true; - } -} - -unsigned ARMInstrInfo::isLoadFromStackSlot(const MachineInstr *MI, - int &FrameIndex) const { - switch (MI->getOpcode()) { - default: break; - case ARM::LDR: - if (MI->getOperand(1).isFI() && - MI->getOperand(2).isReg() && - MI->getOperand(3).isImm() && - MI->getOperand(2).getReg() == 0 && - MI->getOperand(3).getImm() == 0) { - FrameIndex = MI->getOperand(1).getIndex(); - return MI->getOperand(0).getReg(); - } - break; - case ARM::FLDD: - case ARM::FLDS: - if (MI->getOperand(1).isFI() && - MI->getOperand(2).isImm() && - MI->getOperand(2).getImm() == 0) { - FrameIndex = MI->getOperand(1).getIndex(); - return MI->getOperand(0).getReg(); - } - break; - } - return 0; -} - -unsigned ARMInstrInfo::isStoreToStackSlot(const MachineInstr *MI, - int &FrameIndex) const { - switch (MI->getOpcode()) { - default: break; - case ARM::STR: - if (MI->getOperand(1).isFI() && - MI->getOperand(2).isReg() && - MI->getOperand(3).isImm() && - MI->getOperand(2).getReg() == 0 && - MI->getOperand(3).getImm() == 0) { - FrameIndex = MI->getOperand(1).getIndex(); - return MI->getOperand(0).getReg(); - } - break; - case ARM::FSTD: - case ARM::FSTS: - if (MI->getOperand(1).isFI() && - MI->getOperand(2).isImm() && - MI->getOperand(2).getImm() == 0) { - FrameIndex = MI->getOperand(1).getIndex(); - return MI->getOperand(0).getReg(); - } - break; - } - - return 0; -} - void ARMInstrInfo::reMaterialize(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, unsigned DestReg, @@ -335,10 +250,10 @@ ARMBaseInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI, // Branch analysis. bool - ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB, - MachineBasicBlock *&FBB, - SmallVectorImpl<MachineOperand> &Cond, - bool AllowModify) const { +ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB, + MachineBasicBlock *&FBB, + SmallVectorImpl<MachineOperand> &Cond, + bool AllowModify) const { // If the block has no terminators, it just falls into the block after it. MachineBasicBlock::iterator I = MBB.end(); if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) @@ -478,11 +393,288 @@ ARMBaseInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB, return 2; } -bool ARMInstrInfo::copyRegToReg(MachineBasicBlock &MBB, - MachineBasicBlock::iterator I, - unsigned DestReg, unsigned SrcReg, - const TargetRegisterClass *DestRC, - const TargetRegisterClass *SrcRC) const { +bool +ARMBaseInstrInfo::BlockHasNoFallThrough(const MachineBasicBlock &MBB) const { + if (MBB.empty()) return false; + + switch (MBB.back().getOpcode()) { + case ARM::BX_RET: // Return. + case ARM::LDM_RET: + case ARM::tBX_RET: + case ARM::tBX_RET_vararg: + case ARM::tPOP_RET: + case ARM::B: + case ARM::tB: + case ARM::t2B: // Uncond branch. + case ARM::tBR_JTr: + case ARM::t2BR_JTr: + case ARM::BR_JTr: // Jumptable branch. + case ARM::t2BR_JTm: + case ARM::BR_JTm: // Jumptable branch through mem. + case ARM::t2BR_JTadd: + case ARM::BR_JTadd: // Jumptable branch add to pc. + return true; + default: return false; + } +} + +bool ARMBaseInstrInfo:: +ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const { + ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm(); + Cond[0].setImm(ARMCC::getOppositeCondition(CC)); + return false; +} + +bool ARMBaseInstrInfo::isPredicated(const MachineInstr *MI) const { + int PIdx = MI->findFirstPredOperandIdx(); + return PIdx != -1 && MI->getOperand(PIdx).getImm() != ARMCC::AL; +} + +bool ARMBaseInstrInfo:: +PredicateInstruction(MachineInstr *MI, + const SmallVectorImpl<MachineOperand> &Pred) const { + unsigned Opc = MI->getOpcode(); + if (Opc == ARM::B || Opc == ARM::tB || Opc == ARM::t2B) { + MI->setDesc(get((Opc == ARM::B) ? ARM::Bcc : + ((Opc == ARM::tB) ? ARM::tBcc : ARM::t2Bcc))); + MI->addOperand(MachineOperand::CreateImm(Pred[0].getImm())); + MI->addOperand(MachineOperand::CreateReg(Pred[1].getReg(), false)); + return true; + } + + int PIdx = MI->findFirstPredOperandIdx(); + if (PIdx != -1) { + MachineOperand &PMO = MI->getOperand(PIdx); + PMO.setImm(Pred[0].getImm()); + MI->getOperand(PIdx+1).setReg(Pred[1].getReg()); + return true; + } + return false; +} + +bool ARMBaseInstrInfo:: +SubsumesPredicate(const SmallVectorImpl<MachineOperand> &Pred1, + const SmallVectorImpl<MachineOperand> &Pred2) const { + if (Pred1.size() > 2 || Pred2.size() > 2) + return false; + + ARMCC::CondCodes CC1 = (ARMCC::CondCodes)Pred1[0].getImm(); + ARMCC::CondCodes CC2 = (ARMCC::CondCodes)Pred2[0].getImm(); + if (CC1 == CC2) + return true; + + switch (CC1) { + default: + return false; + case ARMCC::AL: + return true; + case ARMCC::HS: + return CC2 == ARMCC::HI; + case ARMCC::LS: + return CC2 == ARMCC::LO || CC2 == ARMCC::EQ; + case ARMCC::GE: + return CC2 == ARMCC::GT; + case ARMCC::LE: + return CC2 == ARMCC::LT; + } +} + +bool ARMBaseInstrInfo::DefinesPredicate(MachineInstr *MI, + std::vector<MachineOperand> &Pred) const { + const TargetInstrDesc &TID = MI->getDesc(); + if (!TID.getImplicitDefs() && !TID.hasOptionalDef()) + return false; + + bool Found = false; + for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { + const MachineOperand &MO = MI->getOperand(i); + if (MO.isReg() && MO.getReg() == ARM::CPSR) { + Pred.push_back(MO); + Found = true; + } + } + + return Found; +} + + +/// FIXME: Works around a gcc miscompilation with -fstrict-aliasing +static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT, + unsigned JTI) DISABLE_INLINE; +static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT, + unsigned JTI) { + return JT[JTI].MBBs.size(); +} + +/// GetInstSize - Return the size of the specified MachineInstr. +/// +unsigned ARMBaseInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const { + const MachineBasicBlock &MBB = *MI->getParent(); + const MachineFunction *MF = MBB.getParent(); + const TargetAsmInfo *TAI = MF->getTarget().getTargetAsmInfo(); + + // Basic size info comes from the TSFlags field. + const TargetInstrDesc &TID = MI->getDesc(); + unsigned TSFlags = TID.TSFlags; + + switch ((TSFlags & ARMII::SizeMask) >> ARMII::SizeShift) { + default: { + // If this machine instr is an inline asm, measure it. + if (MI->getOpcode() == ARM::INLINEASM) + return TAI->getInlineAsmLength(MI->getOperand(0).getSymbolName()); + if (MI->isLabel()) + return 0; + switch (MI->getOpcode()) { + default: + assert(0 && "Unknown or unset size field for instr!"); + break; + case TargetInstrInfo::IMPLICIT_DEF: + case TargetInstrInfo::DECLARE: + case TargetInstrInfo::DBG_LABEL: + case TargetInstrInfo::EH_LABEL: + return 0; + } + break; + } + case ARMII::Size8Bytes: return 8; // Arm instruction x 2. + case ARMII::Size4Bytes: return 4; // Arm instruction. + case ARMII::Size2Bytes: return 2; // Thumb instruction. + case ARMII::SizeSpecial: { + switch (MI->getOpcode()) { + case ARM::CONSTPOOL_ENTRY: + // If this machine instr is a constant pool entry, its size is recorded as + // operand #2. + return MI->getOperand(2).getImm(); + case ARM::Int_eh_sjlj_setjmp: return 12; + case ARM::BR_JTr: + case ARM::BR_JTm: + case ARM::BR_JTadd: + case ARM::t2BR_JTr: + case ARM::t2BR_JTm: + case ARM::t2BR_JTadd: + case ARM::tBR_JTr: { + // These are jumptable branches, i.e. a branch followed by an inlined + // jumptable. The size is 4 + 4 * number of entries. + unsigned NumOps = TID.getNumOperands(); + MachineOperand JTOP = + MI->getOperand(NumOps - (TID.isPredicable() ? 3 : 2)); + unsigned JTI = JTOP.getIndex(); + const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); + const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); + assert(JTI < JT.size()); + // Thumb instructions are 2 byte aligned, but JT entries are 4 byte + // 4 aligned. The assembler / linker may add 2 byte padding just before + // the JT entries. The size does not include this padding; the + // constant islands pass does separate bookkeeping for it. + // FIXME: If we know the size of the function is less than (1 << 16) *2 + // bytes, we can use 16-bit entries instead. Then there won't be an + // alignment issue. + return getNumJTEntries(JT, JTI) * 4 + + ((MI->getOpcode()==ARM::tBR_JTr) ? 2 : 4); + } + default: + // Otherwise, pseudo-instruction sizes are zero. + return 0; + } + } + } + return 0; // Not reached +} + +/// Return true if the instruction is a register to register move and +/// leave the source and dest operands in the passed parameters. +/// +bool +ARMBaseInstrInfo::isMoveInstr(const MachineInstr &MI, + unsigned &SrcReg, unsigned &DstReg, + unsigned& SrcSubIdx, unsigned& DstSubIdx) const { + SrcSubIdx = DstSubIdx = 0; // No sub-registers. + + unsigned oc = MI.getOpcode(); + switch (oc) { + default: + return false; + case ARM::FCPYS: + case ARM::FCPYD: + case ARM::VMOVD: + case ARM::VMOVQ: + SrcReg = MI.getOperand(1).getReg(); + DstReg = MI.getOperand(0).getReg(); + return true; + case ARM::MOVr: + assert(MI.getDesc().getNumOperands() >= 2 && + MI.getOperand(0).isReg() && + MI.getOperand(1).isReg() && + "Invalid ARM MOV instruction"); + SrcReg = MI.getOperand(1).getReg(); + DstReg = MI.getOperand(0).getReg(); + return true; + } +} + +unsigned +ARMBaseInstrInfo::isLoadFromStackSlot(const MachineInstr *MI, + int &FrameIndex) const { + switch (MI->getOpcode()) { + default: break; + case ARM::LDR: + if (MI->getOperand(1).isFI() && + MI->getOperand(2).isReg() && + MI->getOperand(3).isImm() && + MI->getOperand(2).getReg() == 0 && + MI->getOperand(3).getImm() == 0) { + FrameIndex = MI->getOperand(1).getIndex(); + return MI->getOperand(0).getReg(); + } + break; + case ARM::FLDD: + case ARM::FLDS: + if (MI->getOperand(1).isFI() && + MI->getOperand(2).isImm() && + MI->getOperand(2).getImm() == 0) { + FrameIndex = MI->getOperand(1).getIndex(); + return MI->getOperand(0).getReg(); + } + break; + } + return 0; +} + +unsigned +ARMBaseInstrInfo::isStoreToStackSlot(const MachineInstr *MI, + int &FrameIndex) const { + switch (MI->getOpcode()) { + default: break; + case ARM::STR: + if (MI->getOperand(1).isFI() && + MI->getOperand(2).isReg() && + MI->getOperand(3).isImm() && + MI->getOperand(2).getReg() == 0 && + MI->getOperand(3).getImm() == 0) { + FrameIndex = MI->getOperand(1).getIndex(); + return MI->getOperand(0).getReg(); + } + break; + case ARM::FSTD: + case ARM::FSTS: + if (MI->getOperand(1).isFI() && + MI->getOperand(2).isImm() && + MI->getOperand(2).getImm() == 0) { + FrameIndex = MI->getOperand(1).getIndex(); + return MI->getOperand(0).getReg(); + } + break; + } + + return 0; +} + +bool +ARMBaseInstrInfo::copyRegToReg(MachineBasicBlock &MBB, + MachineBasicBlock::iterator I, + unsigned DestReg, unsigned SrcReg, + const TargetRegisterClass *DestRC, + const TargetRegisterClass *SrcRC) const { DebugLoc DL = DebugLoc::getUnknownLoc(); if (I != MBB.end()) DL = I->getDebugLoc(); @@ -508,7 +700,7 @@ bool ARMInstrInfo::copyRegToReg(MachineBasicBlock &MBB, return true; } -void ARMInstrInfo:: +void ARMBaseInstrInfo:: storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, unsigned SrcReg, bool isKill, int FI, const TargetRegisterClass *RC) const { @@ -531,11 +723,12 @@ storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, } } -void ARMInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg, - bool isKill, - SmallVectorImpl<MachineOperand> &Addr, - const TargetRegisterClass *RC, - SmallVectorImpl<MachineInstr*> &NewMIs) const{ +void +ARMBaseInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg, + bool isKill, + SmallVectorImpl<MachineOperand> &Addr, + const TargetRegisterClass *RC, + SmallVectorImpl<MachineInstr*> &NewMIs) const{ DebugLoc DL = DebugLoc::getUnknownLoc(); unsigned Opc = 0; if (RC == ARM::GPRRegisterClass) { @@ -556,7 +749,7 @@ void ARMInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg, return; } -void ARMInstrInfo:: +void ARMBaseInstrInfo:: loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, unsigned DestReg, int FI, const TargetRegisterClass *RC) const { @@ -576,7 +769,7 @@ loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I, } } -void ARMInstrInfo:: +void ARMBaseInstrInfo:: loadRegFromAddr(MachineFunction &MF, unsigned DestReg, SmallVectorImpl<MachineOperand> &Addr, const TargetRegisterClass *RC, @@ -600,7 +793,7 @@ loadRegFromAddr(MachineFunction &MF, unsigned DestReg, return; } -MachineInstr *ARMInstrInfo:: +MachineInstr *ARMBaseInstrInfo:: foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI, const SmallVectorImpl<unsigned> &Ops, int FI) const { if (Ops.size() != 1) return NULL; @@ -688,9 +881,17 @@ foldMemoryOperandImpl(MachineFunction &MF, MachineInstr *MI, return NewMI; } +MachineInstr* +ARMBaseInstrInfo::foldMemoryOperandImpl(MachineFunction &MF, + MachineInstr* MI, + const SmallVectorImpl<unsigned> &Ops, + MachineInstr* LoadMI) const { + return 0; +} + bool -ARMInstrInfo::canFoldMemoryOperand(const MachineInstr *MI, - const SmallVectorImpl<unsigned> &Ops) const { +ARMBaseInstrInfo::canFoldMemoryOperand(const MachineInstr *MI, + const SmallVectorImpl<unsigned> &Ops) const { if (Ops.size() != 1) return false; unsigned Opc = MI->getOpcode(); @@ -710,191 +911,3 @@ ARMInstrInfo::canFoldMemoryOperand(const MachineInstr *MI, return false; } - -bool -ARMBaseInstrInfo::BlockHasNoFallThrough(const MachineBasicBlock &MBB) const { - if (MBB.empty()) return false; - - switch (MBB.back().getOpcode()) { - case ARM::BX_RET: // Return. - case ARM::LDM_RET: - case ARM::tBX_RET: - case ARM::tBX_RET_vararg: - case ARM::tPOP_RET: - case ARM::B: - case ARM::tB: - case ARM::t2B: // Uncond branch. - case ARM::tBR_JTr: - case ARM::t2BR_JTr: - case ARM::BR_JTr: // Jumptable branch. - case ARM::t2BR_JTm: - case ARM::BR_JTm: // Jumptable branch through mem. - case ARM::t2BR_JTadd: - case ARM::BR_JTadd: // Jumptable branch add to pc. - return true; - default: return false; - } -} - -bool ARMBaseInstrInfo:: -ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const { - ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm(); - Cond[0].setImm(ARMCC::getOppositeCondition(CC)); - return false; -} - -bool ARMBaseInstrInfo::isPredicated(const MachineInstr *MI) const { - int PIdx = MI->findFirstPredOperandIdx(); - return PIdx != -1 && MI->getOperand(PIdx).getImm() != ARMCC::AL; -} - -bool ARMBaseInstrInfo:: -PredicateInstruction(MachineInstr *MI, - const SmallVectorImpl<MachineOperand> &Pred) const { - unsigned Opc = MI->getOpcode(); - if (Opc == ARM::B || Opc == ARM::tB || Opc == ARM::t2B) { - MI->setDesc(get((Opc == ARM::B) ? ARM::Bcc : - ((Opc == ARM::tB) ? ARM::tBcc : ARM::t2Bcc))); - MI->addOperand(MachineOperand::CreateImm(Pred[0].getImm())); - MI->addOperand(MachineOperand::CreateReg(Pred[1].getReg(), false)); - return true; - } - - int PIdx = MI->findFirstPredOperandIdx(); - if (PIdx != -1) { - MachineOperand &PMO = MI->getOperand(PIdx); - PMO.setImm(Pred[0].getImm()); - MI->getOperand(PIdx+1).setReg(Pred[1].getReg()); - return true; - } - return false; -} - -bool ARMBaseInstrInfo:: -SubsumesPredicate(const SmallVectorImpl<MachineOperand> &Pred1, - const SmallVectorImpl<MachineOperand> &Pred2) const { - if (Pred1.size() > 2 || Pred2.size() > 2) - return false; - - ARMCC::CondCodes CC1 = (ARMCC::CondCodes)Pred1[0].getImm(); - ARMCC::CondCodes CC2 = (ARMCC::CondCodes)Pred2[0].getImm(); - if (CC1 == CC2) - return true; - - switch (CC1) { - default: - return false; - case ARMCC::AL: - return true; - case ARMCC::HS: - return CC2 == ARMCC::HI; - case ARMCC::LS: - return CC2 == ARMCC::LO || CC2 == ARMCC::EQ; - case ARMCC::GE: - return CC2 == ARMCC::GT; - case ARMCC::LE: - return CC2 == ARMCC::LT; - } -} - -bool ARMBaseInstrInfo::DefinesPredicate(MachineInstr *MI, - std::vector<MachineOperand> &Pred) const { - const TargetInstrDesc &TID = MI->getDesc(); - if (!TID.getImplicitDefs() && !TID.hasOptionalDef()) - return false; - - bool Found = false; - for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { - const MachineOperand &MO = MI->getOperand(i); - if (MO.isReg() && MO.getReg() == ARM::CPSR) { - Pred.push_back(MO); - Found = true; - } - } - - return Found; -} - - -/// FIXME: Works around a gcc miscompilation with -fstrict-aliasing -static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT, - unsigned JTI) DISABLE_INLINE; -static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT, - unsigned JTI) { - return JT[JTI].MBBs.size(); -} - -/// GetInstSize - Return the size of the specified MachineInstr. -/// -unsigned ARMBaseInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const { - const MachineBasicBlock &MBB = *MI->getParent(); - const MachineFunction *MF = MBB.getParent(); - const TargetAsmInfo *TAI = MF->getTarget().getTargetAsmInfo(); - - // Basic size info comes from the TSFlags field. - const TargetInstrDesc &TID = MI->getDesc(); - unsigned TSFlags = TID.TSFlags; - - switch ((TSFlags & ARMII::SizeMask) >> ARMII::SizeShift) { - default: { - // If this machine instr is an inline asm, measure it. - if (MI->getOpcode() == ARM::INLINEASM) - return TAI->getInlineAsmLength(MI->getOperand(0).getSymbolName()); - if (MI->isLabel()) - return 0; - switch (MI->getOpcode()) { - default: - assert(0 && "Unknown or unset size field for instr!"); - break; - case TargetInstrInfo::IMPLICIT_DEF: - case TargetInstrInfo::DECLARE: - case TargetInstrInfo::DBG_LABEL: - case TargetInstrInfo::EH_LABEL: - return 0; - } - break; - } - case ARMII::Size8Bytes: return 8; // Arm instruction x 2. - case ARMII::Size4Bytes: return 4; // Arm instruction. - case ARMII::Size2Bytes: return 2; // Thumb instruction. - case ARMII::SizeSpecial: { - switch (MI->getOpcode()) { - case ARM::CONSTPOOL_ENTRY: - // If this machine instr is a constant pool entry, its size is recorded as - // operand #2. - return MI->getOperand(2).getImm(); - case ARM::Int_eh_sjlj_setjmp: return 12; - case ARM::BR_JTr: - case ARM::BR_JTm: - case ARM::BR_JTadd: - case ARM::t2BR_JTr: - case ARM::t2BR_JTm: - case ARM::t2BR_JTadd: - case ARM::tBR_JTr: { - // These are jumptable branches, i.e. a branch followed by an inlined - // jumptable. The size is 4 + 4 * number of entries. - unsigned NumOps = TID.getNumOperands(); - MachineOperand JTOP = - MI->getOperand(NumOps - (TID.isPredicable() ? 3 : 2)); - unsigned JTI = JTOP.getIndex(); - const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); - const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); - assert(JTI < JT.size()); - // Thumb instructions are 2 byte aligned, but JT entries are 4 byte - // 4 aligned. The assembler / linker may add 2 byte padding just before - // the JT entries. The size does not include this padding; the - // constant islands pass does separate bookkeeping for it. - // FIXME: If we know the size of the function is less than (1 << 16) *2 - // bytes, we can use 16-bit entries instead. Then there won't be an - // alignment issue. - return getNumJTEntries(JT, JTI) * 4 + - ((MI->getOpcode()==ARM::tBR_JTr) ? 2 : 4); - } - default: - // Otherwise, pseudo-instruction sizes are zero. - return 0; - } - } - } - return 0; // Not reached -} |