-//===- MipsInstrInfo.cpp - Mips Instruction Information ---------*- C++ -*-===//
+//===-- MipsInstrInfo.cpp - Mips Instruction Information ------------------===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
-#include "Mips.h"
#include "MipsInstrInfo.h"
+#include "InstPrinter/MipsInstPrinter.h"
+#include "MipsAnalyzeImmediate.h"
+#include "MipsMachineFunction.h"
+#include "MipsSubtarget.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "MipsGenInstrInfo.inc"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/TargetRegistry.h"
using namespace llvm;
-MipsInstrInfo::MipsInstrInfo(MipsTargetMachine &tm)
- : TargetInstrInfoImpl(MipsInsts, array_lengthof(MipsInsts)),
- TM(tm), RI(*this) {}
+#define GET_INSTRINFO_CTOR_DTOR
+#include "MipsGenInstrInfo.inc"
-static bool isZeroImm(const MachineOperand &op) {
- return op.isImmediate() && op.getImm() == 0;
-}
+// Pin the vtable to this file.
+void MipsInstrInfo::anchor() {}
-/// Return true if the instruction is a register to register move and
-/// leave the source and dest operands in the passed parameters.
-bool MipsInstrInfo::
-isMoveInstr(const MachineInstr &MI, unsigned &SrcReg, unsigned &DstReg) const
-{
- // addu $dst, $src, $zero || addu $dst, $zero, $src
- // or $dst, $src, $zero || or $dst, $zero, $src
- if ((MI.getOpcode() == Mips::ADDu) || (MI.getOpcode() == Mips::OR)) {
- if (MI.getOperand(1).getReg() == Mips::ZERO) {
- DstReg = MI.getOperand(0).getReg();
- SrcReg = MI.getOperand(2).getReg();
- return true;
- } else if (MI.getOperand(2).getReg() == Mips::ZERO) {
- DstReg = MI.getOperand(0).getReg();
- SrcReg = MI.getOperand(1).getReg();
- return true;
- }
- }
+MipsInstrInfo::MipsInstrInfo(const MipsSubtarget &STI, unsigned UncondBr)
+ : MipsGenInstrInfo(Mips::ADJCALLSTACKDOWN, Mips::ADJCALLSTACKUP),
+ Subtarget(STI), UncondBrOpc(UncondBr) {}
- // mov $fpDst, $fpSrc
- // mfc $gpDst, $fpSrc
- // mtc $fpDst, $gpSrc
- if (MI.getOpcode() == Mips::FMOV_SO32 || MI.getOpcode() == Mips::FMOV_AS32 ||
- MI.getOpcode() == Mips::FMOV_D32 || MI.getOpcode() == Mips::MFC1A ||
- MI.getOpcode() == Mips::MFC1 || MI.getOpcode() == Mips::MTC1A ||
- MI.getOpcode() == Mips::MTC1 ) {
- DstReg = MI.getOperand(0).getReg();
- SrcReg = MI.getOperand(1).getReg();
- return true;
- }
+const MipsInstrInfo *MipsInstrInfo::create(MipsSubtarget &STI) {
+ if (STI.inMips16Mode())
+ return llvm::createMips16InstrInfo(STI);
- // addiu $dst, $src, 0
- if (MI.getOpcode() == Mips::ADDiu) {
- if ((MI.getOperand(1).isRegister()) && (isZeroImm(MI.getOperand(2)))) {
- DstReg = MI.getOperand(0).getReg();
- SrcReg = MI.getOperand(1).getReg();
- return true;
- }
- }
- return false;
+ return llvm::createMipsSEInstrInfo(STI);
}
-/// isLoadFromStackSlot - If the specified machine instruction is a direct
-/// load from a stack slot, return the virtual or physical register number of
-/// the destination along with the FrameIndex of the loaded stack slot. If
-/// not, return 0. This predicate must return 0 if the instruction has
-/// any side effects other than loading from the stack slot.
-unsigned MipsInstrInfo::
-isLoadFromStackSlot(MachineInstr *MI, int &FrameIndex) const
-{
- if ((MI->getOpcode() == Mips::LW) || (MI->getOpcode() == Mips::LWC1) ||
- (MI->getOpcode() == Mips::LWC1A) || (MI->getOpcode() == Mips::LDC1)) {
- if ((MI->getOperand(2).isFrameIndex()) && // is a stack slot
- (MI->getOperand(1).isImmediate()) && // the imm is zero
- (isZeroImm(MI->getOperand(1)))) {
- FrameIndex = MI->getOperand(2).getIndex();
- return MI->getOperand(0).getReg();
- }
- }
-
- return 0;
-}
-
-/// isStoreToStackSlot - If the specified machine instruction is a direct
-/// store to a stack slot, return the virtual or physical register number of
-/// the source reg along with the FrameIndex of the loaded stack slot. If
-/// not, return 0. This predicate must return 0 if the instruction has
-/// any side effects other than storing to the stack slot.
-unsigned MipsInstrInfo::
-isStoreToStackSlot(MachineInstr *MI, int &FrameIndex) const
-{
- if ((MI->getOpcode() == Mips::SW) || (MI->getOpcode() == Mips::SWC1) ||
- (MI->getOpcode() == Mips::SWC1A) || (MI->getOpcode() == Mips::SDC1)) {
- if ((MI->getOperand(0).isFrameIndex()) && // is a stack slot
- (MI->getOperand(1).isImmediate()) && // the imm is zero
- (isZeroImm(MI->getOperand(1)))) {
- FrameIndex = MI->getOperand(0).getIndex();
- return MI->getOperand(2).getReg();
- }
- }
- return 0;
+bool MipsInstrInfo::isZeroImm(const MachineOperand &op) const {
+ return op.isImm() && op.getImm() == 0;
}
/// insertNoop - If data hazard condition is found insert the target nop
/// instruction.
void MipsInstrInfo::
-insertNoop(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const
+insertNoop(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const
{
- BuildMI(MBB, MI, get(Mips::NOP));
+ DebugLoc DL;
+ BuildMI(MBB, MI, DL, get(Mips::NOP));
}
-void MipsInstrInfo::
-copyRegToReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
- unsigned DestReg, unsigned SrcReg,
- const TargetRegisterClass *DestRC,
- const TargetRegisterClass *SrcRC) const {
- if (DestRC != SrcRC) {
- if ((DestRC == Mips::CPURegsRegisterClass) &&
- (SrcRC == Mips::FGR32RegisterClass))
- BuildMI(MBB, I, get(Mips::MFC1), DestReg).addReg(SrcReg);
- else if ((DestRC == Mips::CPURegsRegisterClass) &&
- (SrcRC == Mips::AFGR32RegisterClass))
- BuildMI(MBB, I, get(Mips::MFC1A), DestReg).addReg(SrcReg);
- else if ((DestRC == Mips::FGR32RegisterClass) &&
- (SrcRC == Mips::CPURegsRegisterClass))
- BuildMI(MBB, I, get(Mips::MTC1), DestReg).addReg(SrcReg);
- else if ((DestRC == Mips::AFGR32RegisterClass) &&
- (SrcRC == Mips::CPURegsRegisterClass))
- BuildMI(MBB, I, get(Mips::MTC1A), DestReg).addReg(SrcReg);
- else
- assert (0 && "DestRC != SrcRC, Can't copy this register");
- }
+MachineMemOperand *MipsInstrInfo::GetMemOperand(MachineBasicBlock &MBB, int FI,
+ unsigned Flag) const {
+ MachineFunction &MF = *MBB.getParent();
+ MachineFrameInfo &MFI = *MF.getFrameInfo();
+ unsigned Align = MFI.getObjectAlignment(FI);
- if (DestRC == Mips::CPURegsRegisterClass)
- BuildMI(MBB, I, get(Mips::ADDu), DestReg).addReg(Mips::ZERO)
- .addReg(SrcReg);
- else if (DestRC == Mips::FGR32RegisterClass)
- BuildMI(MBB, I, get(Mips::FMOV_SO32), DestReg).addReg(SrcReg);
- else if (DestRC == Mips::AFGR32RegisterClass)
- BuildMI(MBB, I, get(Mips::FMOV_AS32), DestReg).addReg(SrcReg);
- else if (DestRC == Mips::AFGR64RegisterClass)
- BuildMI(MBB, I, get(Mips::FMOV_D32), DestReg).addReg(SrcReg);
- else
- assert (0 && "Can't copy this register");
+ return MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(MF, FI),
+ Flag, MFI.getObjectSize(FI), Align);
}
-void MipsInstrInfo::
-storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
- unsigned SrcReg, bool isKill, int FI,
- const TargetRegisterClass *RC) const
-{
- unsigned Opc;
- if (RC == Mips::CPURegsRegisterClass)
- Opc = Mips::SW;
- else if (RC == Mips::FGR32RegisterClass)
- Opc = Mips::SWC1;
- else if (RC == Mips::AFGR32RegisterClass)
- Opc = Mips::SWC1A;
- else if (RC == Mips::AFGR64RegisterClass)
- Opc = Mips::SDC1;
- else
- assert(0 && "Can't store this register to stack slot");
-
- BuildMI(MBB, I, get(Opc)).addReg(SrcReg, false, false, isKill)
- .addImm(0).addFrameIndex(FI);
-}
+//===----------------------------------------------------------------------===//
+// Branch Analysis
+//===----------------------------------------------------------------------===//
-void MipsInstrInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
- bool isKill, SmallVectorImpl<MachineOperand> &Addr,
- const TargetRegisterClass *RC, SmallVectorImpl<MachineInstr*> &NewMIs) const
-{
- unsigned Opc;
- if (RC == Mips::CPURegsRegisterClass)
- Opc = Mips::SW;
- else if (RC == Mips::FGR32RegisterClass)
- Opc = Mips::SWC1;
- else if (RC == Mips::AFGR32RegisterClass)
- Opc = Mips::SWC1A;
- else if (RC == Mips::AFGR64RegisterClass)
- Opc = Mips::SDC1;
- else
- assert(0 && "Can't store this register");
-
- MachineInstrBuilder MIB = BuildMI(get(Opc))
- .addReg(SrcReg, false, false, isKill);
- for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
- MachineOperand &MO = Addr[i];
- if (MO.isRegister())
- MIB.addReg(MO.getReg());
- else if (MO.isImmediate())
- MIB.addImm(MO.getImm());
- else
- MIB.addFrameIndex(MO.getIndex());
- }
- NewMIs.push_back(MIB);
- return;
+void MipsInstrInfo::AnalyzeCondBr(const MachineInstr *Inst, unsigned Opc,
+ MachineBasicBlock *&BB,
+ SmallVectorImpl<MachineOperand> &Cond) const {
+ assert(getAnalyzableBrOpc(Opc) && "Not an analyzable branch");
+ int NumOp = Inst->getNumExplicitOperands();
+
+ // for both int and fp branches, the last explicit operand is the
+ // MBB.
+ BB = Inst->getOperand(NumOp-1).getMBB();
+ Cond.push_back(MachineOperand::CreateImm(Opc));
+
+ for (int i=0; i<NumOp-1; i++)
+ Cond.push_back(Inst->getOperand(i));
}
-void MipsInstrInfo::
-loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
- unsigned DestReg, int FI,
- const TargetRegisterClass *RC) const
-{
- unsigned Opc;
- if (RC == Mips::CPURegsRegisterClass)
- Opc = Mips::LW;
- else if (RC == Mips::FGR32RegisterClass)
- Opc = Mips::LWC1;
- else if (RC == Mips::AFGR32RegisterClass)
- Opc = Mips::LWC1A;
- else if (RC == Mips::AFGR64RegisterClass)
- Opc = Mips::LDC1;
- else
- assert(0 && "Can't load this register from stack slot");
-
- BuildMI(MBB, I, get(Opc), DestReg).addImm(0).addFrameIndex(FI);
+bool MipsInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
+ MachineBasicBlock *&TBB,
+ MachineBasicBlock *&FBB,
+ SmallVectorImpl<MachineOperand> &Cond,
+ bool AllowModify) const {
+ SmallVector<MachineInstr*, 2> BranchInstrs;
+ BranchType BT = AnalyzeBranch(MBB, TBB, FBB, Cond, AllowModify, BranchInstrs);
+
+ return (BT == BT_None) || (BT == BT_Indirect);
}
-void MipsInstrInfo::loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
- SmallVectorImpl<MachineOperand> &Addr,
- const TargetRegisterClass *RC,
- SmallVectorImpl<MachineInstr*> &NewMIs) const {
- unsigned Opc;
- if (RC == Mips::CPURegsRegisterClass)
- Opc = Mips::LW;
- else if (RC == Mips::FGR32RegisterClass)
- Opc = Mips::LWC1;
- else if (RC == Mips::AFGR32RegisterClass)
- Opc = Mips::LWC1A;
- else if (RC == Mips::AFGR64RegisterClass)
- Opc = Mips::LDC1;
- else
- assert(0 && "Can't load this register");
-
- MachineInstrBuilder MIB = BuildMI(get(Opc), DestReg);
- for (unsigned i = 0, e = Addr.size(); i != e; ++i) {
- MachineOperand &MO = Addr[i];
- if (MO.isRegister())
- MIB.addReg(MO.getReg());
- else if (MO.isImmediate())
- MIB.addImm(MO.getImm());
+void
+MipsInstrInfo::BuildCondBr(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
+ DebugLoc DL, ArrayRef<MachineOperand> Cond) const {
+ unsigned Opc = Cond[0].getImm();
+ const MCInstrDesc &MCID = get(Opc);
+ MachineInstrBuilder MIB = BuildMI(&MBB, DL, MCID);
+
+ for (unsigned i = 1; i < Cond.size(); ++i) {
+ if (Cond[i].isReg())
+ MIB.addReg(Cond[i].getReg());
+ else if (Cond[i].isImm())
+ MIB.addImm(Cond[i].getImm());
else
- MIB.addFrameIndex(MO.getIndex());
+ assert(true && "Cannot copy operand");
}
- NewMIs.push_back(MIB);
- return;
+ MIB.addMBB(TBB);
}
-MachineInstr *MipsInstrInfo::
-foldMemoryOperand(MachineFunction &MF,
- MachineInstr* MI,
- SmallVectorImpl<unsigned> &Ops, int FI) const
-{
- if (Ops.size() != 1) return NULL;
+unsigned MipsInstrInfo::InsertBranch(
+ MachineBasicBlock &MBB, MachineBasicBlock *TBB, MachineBasicBlock *FBB,
+ ArrayRef<MachineOperand> Cond, DebugLoc DL) const {
+ // Shouldn't be a fall through.
+ assert(TBB && "InsertBranch must not be told to insert a fallthrough");
- MachineInstr *NewMI = NULL;
+ // # of condition operands:
+ // Unconditional branches: 0
+ // Floating point branches: 1 (opc)
+ // Int BranchZero: 2 (opc, reg)
+ // Int Branch: 3 (opc, reg0, reg1)
+ assert((Cond.size() <= 3) &&
+ "# of Mips branch conditions must be <= 3!");
- switch (MI->getOpcode()) {
- case Mips::ADDu:
- if ((MI->getOperand(0).isRegister()) &&
- (MI->getOperand(1).isRegister()) &&
- (MI->getOperand(1).getReg() == Mips::ZERO) &&
- (MI->getOperand(2).isRegister())) {
- if (Ops[0] == 0) { // COPY -> STORE
- unsigned SrcReg = MI->getOperand(2).getReg();
- bool isKill = MI->getOperand(2).isKill();
- NewMI = BuildMI(get(Mips::SW)).addFrameIndex(FI)
- .addImm(0).addReg(SrcReg, false, false, isKill);
- } else { // COPY -> LOAD
- unsigned DstReg = MI->getOperand(0).getReg();
- bool isDead = MI->getOperand(0).isDead();
- NewMI = BuildMI(get(Mips::LW))
- .addReg(DstReg, true, false, false, isDead)
- .addImm(0).addFrameIndex(FI);
- }
- }
- break;
- case Mips::FMOV_SO32:
- case Mips::FMOV_AS32:
- case Mips::FMOV_D32:
- if ((MI->getOperand(0).isRegister()) &&
- (MI->getOperand(1).isRegister())) {
- const TargetRegisterClass *RC = RI.getRegClass(MI->getOperand(0).getReg());
- unsigned StoreOpc, LoadOpc;
-
- if (RC == Mips::FGR32RegisterClass) {
- LoadOpc = Mips::LWC1; StoreOpc = Mips::SWC1;
- } else if (RC == Mips::AFGR32RegisterClass) {
- LoadOpc = Mips::LWC1A; StoreOpc = Mips::SWC1A;
- } else if (RC == Mips::AFGR64RegisterClass) {
- LoadOpc = Mips::LDC1; StoreOpc = Mips::SDC1;
- } else
- assert(0 && "foldMemoryOperand register unknown");
-
- if (Ops[0] == 0) { // COPY -> STORE
- unsigned SrcReg = MI->getOperand(1).getReg();
- bool isKill = MI->getOperand(1).isKill();
- NewMI = BuildMI(get(StoreOpc)).addFrameIndex(FI)
- .addImm(0).addReg(SrcReg, false, false, isKill);
- } else { // COPY -> LOAD
- unsigned DstReg = MI->getOperand(0).getReg();
- bool isDead = MI->getOperand(0).isDead();
- NewMI = BuildMI(get(LoadOpc))
- .addReg(DstReg, true, false, false, isDead)
- .addImm(0).addFrameIndex(FI);
- }
- }
- break;
+ // Two-way Conditional branch.
+ if (FBB) {
+ BuildCondBr(MBB, TBB, DL, Cond);
+ BuildMI(&MBB, DL, get(UncondBrOpc)).addMBB(FBB);
+ return 2;
}
- return NewMI;
+ // One way branch.
+ // Unconditional branch.
+ if (Cond.empty())
+ BuildMI(&MBB, DL, get(UncondBrOpc)).addMBB(TBB);
+ else // Conditional branch.
+ BuildCondBr(MBB, TBB, DL, Cond);
+ return 1;
}
-//===----------------------------------------------------------------------===//
-// Branch Analysis
-//===----------------------------------------------------------------------===//
+unsigned MipsInstrInfo::RemoveBranch(MachineBasicBlock &MBB) const {
+ MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
+ MachineBasicBlock::reverse_iterator FirstBr;
+ unsigned removed;
-/// GetCondFromBranchOpc - Return the Mips CC that matches
-/// the correspondent Branch instruction opcode.
-static Mips::CondCode GetCondFromBranchOpc(unsigned BrOpc)
-{
- switch (BrOpc) {
- default: return Mips::COND_INVALID;
- case Mips::BEQ : return Mips::COND_E;
- case Mips::BNE : return Mips::COND_NE;
- case Mips::BGTZ : return Mips::COND_GZ;
- case Mips::BGEZ : return Mips::COND_GEZ;
- case Mips::BLTZ : return Mips::COND_LZ;
- case Mips::BLEZ : return Mips::COND_LEZ;
- }
-}
+ // Skip all the debug instructions.
+ while (I != REnd && I->isDebugValue())
+ ++I;
-/// GetCondBranchFromCond - Return the Branch instruction
-/// opcode that matches the cc.
-unsigned Mips::GetCondBranchFromCond(Mips::CondCode CC)
-{
- switch (CC) {
- default: assert(0 && "Illegal condition code!");
- case Mips::COND_E : return Mips::BEQ;
- case Mips::COND_NE : return Mips::BNE;
- case Mips::COND_GZ : return Mips::BGTZ;
- case Mips::COND_GEZ : return Mips::BGEZ;
- case Mips::COND_LZ : return Mips::BLTZ;
- case Mips::COND_LEZ : return Mips::BLEZ;
- }
-}
+ FirstBr = I;
-/// GetOppositeBranchCondition - Return the inverse of the specified
-/// condition, e.g. turning COND_E to COND_NE.
-Mips::CondCode Mips::GetOppositeBranchCondition(Mips::CondCode CC)
-{
- switch (CC) {
- default: assert(0 && "Illegal condition code!");
- case Mips::COND_E : return Mips::COND_NE;
- case Mips::COND_NE : return Mips::COND_E;
- case Mips::COND_GZ : return Mips::COND_LEZ;
- case Mips::COND_GEZ : return Mips::COND_LZ;
- case Mips::COND_LZ : return Mips::COND_GEZ;
- case Mips::COND_LEZ : return Mips::COND_GZ;
- case Mips::FCOND_F : return Mips::FCOND_T;
- case Mips::FCOND_UN : return Mips::FCOND_OR;
- case Mips::FCOND_EQ : return Mips::FCOND_NEQ;
- case Mips::FCOND_UEQ: return Mips::FCOND_OGL;
- case Mips::FCOND_OLT: return Mips::FCOND_UGE;
- case Mips::FCOND_ULT: return Mips::FCOND_OGE;
- case Mips::FCOND_OLE: return Mips::FCOND_UGT;
- case Mips::FCOND_ULE: return Mips::FCOND_OGT;
- case Mips::FCOND_SF: return Mips::FCOND_ST;
- case Mips::FCOND_NGLE:return Mips::FCOND_GLE;
- case Mips::FCOND_SEQ: return Mips::FCOND_SNE;
- case Mips::FCOND_NGL: return Mips::FCOND_GL;
- case Mips::FCOND_LT: return Mips::FCOND_NLT;
- case Mips::FCOND_NGE: return Mips::FCOND_GE;
- case Mips::FCOND_LE: return Mips::FCOND_NLE;
- case Mips::FCOND_NGT: return Mips::FCOND_GT;
- }
-}
+ // Up to 2 branches are removed.
+ // Note that indirect branches are not removed.
+ for (removed = 0; I != REnd && removed < 2; ++I, ++removed)
+ if (!getAnalyzableBrOpc(I->getOpcode()))
+ break;
-bool MipsInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
- MachineBasicBlock *&TBB,
- MachineBasicBlock *&FBB,
- std::vector<MachineOperand> &Cond) 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))
- return false;
-
- // Get the last instruction in the block.
- MachineInstr *LastInst = I;
-
- // If there is only one terminator instruction, process it.
- unsigned LastOpc = LastInst->getOpcode();
- if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
- if (!LastInst->getDesc().isBranch())
- return true;
+ MBB.erase(I.base(), FirstBr.base());
- // Unconditional branch
- if (LastOpc == Mips::J) {
- TBB = LastInst->getOperand(0).getMBB();
- return false;
- }
+ return removed;
+}
- Mips::CondCode BranchCode = GetCondFromBranchOpc(LastInst->getOpcode());
- if (BranchCode == Mips::COND_INVALID)
- return true; // Can't handle indirect branch.
+/// ReverseBranchCondition - Return the inverse opcode of the
+/// specified Branch instruction.
+bool MipsInstrInfo::ReverseBranchCondition(
+ SmallVectorImpl<MachineOperand> &Cond) const {
+ assert( (Cond.size() && Cond.size() <= 3) &&
+ "Invalid Mips branch condition!");
+ Cond[0].setImm(getOppositeBranchOpc(Cond[0].getImm()));
+ return false;
+}
- // Conditional branch
- // Block ends with fall-through condbranch.
- if (LastOpc != Mips::COND_INVALID) {
- int LastNumOp = LastInst->getNumOperands();
+MipsInstrInfo::BranchType MipsInstrInfo::AnalyzeBranch(
+ MachineBasicBlock &MBB, MachineBasicBlock *&TBB, MachineBasicBlock *&FBB,
+ SmallVectorImpl<MachineOperand> &Cond, bool AllowModify,
+ SmallVectorImpl<MachineInstr *> &BranchInstrs) const {
- TBB = LastInst->getOperand(LastNumOp-1).getMBB();
- Cond.push_back(MachineOperand::CreateImm(BranchCode));
+ MachineBasicBlock::reverse_iterator I = MBB.rbegin(), REnd = MBB.rend();
- for (int i=0; i<LastNumOp-1; i++) {
- Cond.push_back(LastInst->getOperand(i));
- }
+ // Skip all the debug instructions.
+ while (I != REnd && I->isDebugValue())
+ ++I;
- return false;
- }
+ if (I == REnd || !isUnpredicatedTerminator(&*I)) {
+ // This block ends with no branches (it just falls through to its succ).
+ // Leave TBB/FBB null.
+ TBB = FBB = nullptr;
+ return BT_NoBranch;
}
-
- // Get the instruction before it if it is a terminator.
- MachineInstr *SecondLastInst = I;
-
- // If there are three terminators, we don't know what sort of block this is.
- if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(--I))
- return true;
- // If the block ends with Mips::J and a Mips::BNE/Mips::BEQ, handle it.
- unsigned SecondLastOpc = SecondLastInst->getOpcode();
- Mips::CondCode BranchCode = GetCondFromBranchOpc(SecondLastOpc);
+ MachineInstr *LastInst = &*I;
+ unsigned LastOpc = LastInst->getOpcode();
+ BranchInstrs.push_back(LastInst);
- if (SecondLastOpc != Mips::COND_INVALID && LastOpc == Mips::J) {
- int SecondNumOp = SecondLastInst->getNumOperands();
+ // Not an analyzable branch (e.g., indirect jump).
+ if (!getAnalyzableBrOpc(LastOpc))
+ return LastInst->isIndirectBranch() ? BT_Indirect : BT_None;
- TBB = SecondLastInst->getOperand(SecondNumOp-1).getMBB();
- Cond.push_back(MachineOperand::CreateImm(BranchCode));
+ // Get the second to last instruction in the block.
+ unsigned SecondLastOpc = 0;
+ MachineInstr *SecondLastInst = nullptr;
- for (int i=0; i<SecondNumOp-1; i++) {
- Cond.push_back(SecondLastInst->getOperand(i));
- }
+ if (++I != REnd) {
+ SecondLastInst = &*I;
+ SecondLastOpc = getAnalyzableBrOpc(SecondLastInst->getOpcode());
- FBB = LastInst->getOperand(0).getMBB();
- return false;
+ // Not an analyzable branch (must be an indirect jump).
+ if (isUnpredicatedTerminator(SecondLastInst) && !SecondLastOpc)
+ return BT_None;
}
-
- // If the block ends with two unconditional branches, handle it. The last
- // one is not executed, so remove it.
- if ((SecondLastOpc == Mips::J) && (LastOpc == Mips::J)) {
- TBB = SecondLastInst->getOperand(0).getMBB();
- I = LastInst;
- I->eraseFromParent();
- return false;
+
+ // If there is only one terminator instruction, process it.
+ if (!SecondLastOpc) {
+ // Unconditional branch.
+ if (LastOpc == UncondBrOpc) {
+ TBB = LastInst->getOperand(0).getMBB();
+ return BT_Uncond;
+ }
+
+ // Conditional branch
+ AnalyzeCondBr(LastInst, LastOpc, TBB, Cond);
+ return BT_Cond;
}
- // Otherwise, can't handle this.
- return true;
-}
+ // If we reached here, there are two branches.
+ // If there are three terminators, we don't know what sort of block this is.
+ if (++I != REnd && isUnpredicatedTerminator(&*I))
+ return BT_None;
-unsigned MipsInstrInfo::
-InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
- MachineBasicBlock *FBB, const std::vector<MachineOperand> &Cond)
- const
-{
- // Shouldn't be a fall through.
- assert(TBB && "InsertBranch must not be told to insert a fallthrough");
- assert((Cond.size() == 3 || Cond.size() == 2 || Cond.size() == 0) &&
- "Mips branch conditions can have two|three components!");
-
- if (FBB == 0) { // One way branch.
- if (Cond.empty()) {
- // Unconditional branch?
- BuildMI(&MBB, get(Mips::J)).addMBB(TBB);
- } else {
- // Conditional branch.
- unsigned Opc = GetCondBranchFromCond((Mips::CondCode)Cond[0].getImm());
- const TargetInstrDesc &TID = get(Opc);
-
- if (TID.getNumOperands() == 3)
- BuildMI(&MBB, TID).addReg(Cond[1].getReg())
- .addReg(Cond[2].getReg())
- .addMBB(TBB);
- else
- BuildMI(&MBB, TID).addReg(Cond[1].getReg())
- .addMBB(TBB);
-
- }
- return 1;
+ BranchInstrs.insert(BranchInstrs.begin(), SecondLastInst);
+
+ // If second to last instruction is an unconditional branch,
+ // analyze it and remove the last instruction.
+ if (SecondLastOpc == UncondBrOpc) {
+ // Return if the last instruction cannot be removed.
+ if (!AllowModify)
+ return BT_None;
+
+ TBB = SecondLastInst->getOperand(0).getMBB();
+ LastInst->eraseFromParent();
+ BranchInstrs.pop_back();
+ return BT_Uncond;
}
-
- // Two-way Conditional branch.
- unsigned Opc = GetCondBranchFromCond((Mips::CondCode)Cond[0].getImm());
- const TargetInstrDesc &TID = get(Opc);
- if (TID.getNumOperands() == 3)
- BuildMI(&MBB, TID).addReg(Cond[1].getReg()).addReg(Cond[2].getReg())
- .addMBB(TBB);
- else
- BuildMI(&MBB, TID).addReg(Cond[1].getReg()).addMBB(TBB);
+ // Conditional branch followed by an unconditional branch.
+ // The last one must be unconditional.
+ if (LastOpc != UncondBrOpc)
+ return BT_None;
- BuildMI(&MBB, get(Mips::J)).addMBB(FBB);
- return 2;
-}
+ AnalyzeCondBr(SecondLastInst, SecondLastOpc, TBB, Cond);
+ FBB = LastInst->getOperand(0).getMBB();
-unsigned MipsInstrInfo::
-RemoveBranch(MachineBasicBlock &MBB) const
-{
- MachineBasicBlock::iterator I = MBB.end();
- if (I == MBB.begin()) return 0;
- --I;
- if (I->getOpcode() != Mips::J &&
- GetCondFromBranchOpc(I->getOpcode()) == Mips::COND_INVALID)
- return 0;
-
- // Remove the branch.
- I->eraseFromParent();
-
- I = MBB.end();
-
- if (I == MBB.begin()) return 1;
- --I;
- if (GetCondFromBranchOpc(I->getOpcode()) == Mips::COND_INVALID)
- return 1;
-
- // Remove the branch.
- I->eraseFromParent();
- return 2;
+ return BT_CondUncond;
}
-/// BlockHasNoFallThrough - Analyse if MachineBasicBlock does not
-/// fall-through into its successor block.
-bool MipsInstrInfo::
-BlockHasNoFallThrough(MachineBasicBlock &MBB) const
-{
- if (MBB.empty()) return false;
-
- switch (MBB.back().getOpcode()) {
- case Mips::RET: // Return.
- case Mips::JR: // Indirect branch.
- case Mips::J: // Uncond branch.
- return true;
- default: return false;
+/// Return the number of bytes of code the specified instruction may be.
+unsigned MipsInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
+ switch (MI->getOpcode()) {
+ default:
+ return MI->getDesc().getSize();
+ case TargetOpcode::INLINEASM: { // Inline Asm: Variable size.
+ const MachineFunction *MF = MI->getParent()->getParent();
+ const char *AsmStr = MI->getOperand(0).getSymbolName();
+ return getInlineAsmLength(AsmStr, *MF->getTarget().getMCAsmInfo());
+ }
+ case Mips::CONSTPOOL_ENTRY:
+ // If this machine instr is a constant pool entry, its size is recorded as
+ // operand #2.
+ return MI->getOperand(2).getImm();
}
}
-/// ReverseBranchCondition - Return the inverse opcode of the
-/// specified Branch instruction.
-bool MipsInstrInfo::
-ReverseBranchCondition(std::vector<MachineOperand> &Cond) const
-{
- assert( (Cond.size() == 3 || Cond.size() == 2) &&
- "Invalid Mips branch condition!");
- Cond[0].setImm(GetOppositeBranchCondition((Mips::CondCode)Cond[0].getImm()));
- return false;
+MachineInstrBuilder
+MipsInstrInfo::genInstrWithNewOpc(unsigned NewOpc,
+ MachineBasicBlock::iterator I) const {
+ MachineInstrBuilder MIB;
+ MIB = BuildMI(*I->getParent(), I, I->getDebugLoc(), get(NewOpc));
+
+ for (unsigned J = 0, E = I->getDesc().getNumOperands(); J < E; ++J)
+ MIB.addOperand(I->getOperand(J));
+
+ MIB.setMemRefs(I->memoperands_begin(), I->memoperands_end());
+ return MIB;
}