-
-unsigned ARMInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
- MachineFunction &MF = *MBB.getParent();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- int BOpc = AFI->isThumbFunction() ? ARM::tB : ARM::B;
- int BccOpc = AFI->isThumbFunction() ? ARM::tBcc : ARM::Bcc;
-
- MachineBasicBlock::iterator I = MBB.end();
- if (I == MBB.begin()) return 0;
- --I;
- if (I->getOpcode() != BOpc && I->getOpcode() != BccOpc)
- return 0;
-
- // Remove the branch.
- I->eraseFromParent();
-
- I = MBB.end();
-
- if (I == MBB.begin()) return 1;
- --I;
- if (I->getOpcode() != BccOpc)
- return 1;
-
- // Remove the branch.
- I->eraseFromParent();
- return 2;
-}
-
-unsigned ARMInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
- MachineBasicBlock *FBB,
- const std::vector<MachineOperand> &Cond) const {
- MachineFunction &MF = *MBB.getParent();
- ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
- int BOpc = AFI->isThumbFunction() ? ARM::tB : ARM::B;
- int BccOpc = AFI->isThumbFunction() ? ARM::tBcc : ARM::Bcc;
-
- // Shouldn't be a fall through.
- assert(TBB && "InsertBranch must not be told to insert a fallthrough");
- assert((Cond.size() == 2 || Cond.size() == 0) &&
- "ARM branch conditions have two components!");
-
- if (FBB == 0) {
- if (Cond.empty()) // Unconditional branch?
- BuildMI(&MBB, get(BOpc)).addMBB(TBB);
- else
- BuildMI(&MBB, get(BccOpc)).addMBB(TBB)
- .addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
- return 1;
- }
-
- // Two-way conditional branch.
- BuildMI(&MBB, get(BccOpc)).addMBB(TBB)
- .addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
- BuildMI(&MBB, get(BOpc)).addMBB(FBB);
- return 2;
-}
-
-bool ARMInstrInfo::BlockHasNoFallThrough(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: // Uncond branch.
- case ARM::tBR_JTr:
- case ARM::BR_JTr: // Jumptable branch.
- case ARM::BR_JTm: // Jumptable branch through mem.
- case ARM::BR_JTadd: // Jumptable branch add to pc.
- return true;
- default: return false;
- }
-}
-
-bool ARMInstrInfo::
-ReverseBranchCondition(std::vector<MachineOperand> &Cond) const {
- ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
- Cond[0].setImm(ARMCC::getOppositeCondition(CC));
- return false;
-}
-
-bool ARMInstrInfo::isPredicated(const MachineInstr *MI) const {
- int PIdx = MI->findFirstPredOperandIdx();
- return PIdx != -1 && MI->getOperand(PIdx).getImm() != ARMCC::AL;
-}
-
-bool ARMInstrInfo::PredicateInstruction(MachineInstr *MI,
- const std::vector<MachineOperand> &Pred) const {
- unsigned Opc = MI->getOpcode();
- if (Opc == ARM::B || Opc == ARM::tB) {
- MI->setInstrDescriptor(get(Opc == ARM::B ? ARM::Bcc : ARM::tBcc));
- 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
-ARMInstrInfo::SubsumesPredicate(const std::vector<MachineOperand> &Pred1,
- const std::vector<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 ARMInstrInfo::DefinesPredicate(MachineInstr *MI,
- std::vector<MachineOperand> &Pred) const {
- const TargetInstrDescriptor *TID = MI->getInstrDescriptor();
- if (!TID->ImplicitDefs && (TID->Flags & M_HAS_OPTIONAL_DEF) == 0)
- return false;
-
- bool Found = false;
- for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
- const MachineOperand &MO = MI->getOperand(i);
- if (MO.isRegister() && 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 ARM::GetInstSize(MachineInstr *MI) {
- MachineBasicBlock &MBB = *MI->getParent();
- const MachineFunction *MF = MBB.getParent();
- const TargetAsmInfo *TAI = MF->getTarget().getTargetAsmInfo();
-
- // Basic size info comes from the TSFlags field.
- const TargetInstrDescriptor *TID = MI->getInstrDescriptor();
- 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->getOpcode() == ARM::LABEL)
- return 0;
- assert(0 && "Unknown or unset size field for instr!");
- 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::BR_JTr:
- case ARM::BR_JTm:
- case ARM::BR_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->numOperands;
- MachineOperand JTOP =
- MI->getOperand(NumOps - ((TID->Flags & M_PREDICABLE) ? 3 : 2));
- unsigned JTI = JTOP.getJumpTableIndex();
- 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);