//===----------------------------------------------------------------------===//
#include "SystemZInstrInfo.h"
+#include "SystemZTargetMachine.h"
#include "SystemZInstrBuilder.h"
+#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Target/TargetMachine.h"
#define GET_INSTRINFO_CTOR
#define GET_INSTRMAP_INFO
using namespace llvm;
+// Return a mask with Count low bits set.
+static uint64_t allOnes(unsigned int Count) {
+ return Count == 0 ? 0 : (uint64_t(1) << (Count - 1) << 1) - 1;
+}
+
SystemZInstrInfo::SystemZInstrInfo(SystemZTargetMachine &tm)
: SystemZGenInstrInfo(SystemZ::ADJCALLSTACKDOWN, SystemZ::ADJCALLSTACKUP),
- RI(tm) {
+ RI(tm), TM(tm) {
}
// MI is a 128-bit load or store. Split it into two 64-bit loads or stores,
return isSimpleMove(MI, FrameIndex, SystemZII::SimpleBDXStore);
}
+bool SystemZInstrInfo::isStackSlotCopy(const MachineInstr *MI,
+ int &DestFrameIndex,
+ int &SrcFrameIndex) const {
+ // Check for MVC 0(Length,FI1),0(FI2)
+ const MachineFrameInfo *MFI = MI->getParent()->getParent()->getFrameInfo();
+ if (MI->getOpcode() != SystemZ::MVC ||
+ !MI->getOperand(0).isFI() ||
+ MI->getOperand(1).getImm() != 0 ||
+ !MI->getOperand(3).isFI() ||
+ MI->getOperand(4).getImm() != 0)
+ return false;
+
+ // Check that Length covers the full slots.
+ int64_t Length = MI->getOperand(2).getImm();
+ unsigned FI1 = MI->getOperand(0).getIndex();
+ unsigned FI2 = MI->getOperand(3).getIndex();
+ if (MFI->getObjectSize(FI1) != Length ||
+ MFI->getObjectSize(FI2) != Length)
+ return false;
+
+ DestFrameIndex = FI1;
+ SrcFrameIndex = FI2;
+ return true;
+}
+
bool SystemZInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
// FIXME: add X86-style branch swap
FBB = TBB;
TBB = Branch.Target->getMBB();
+ Cond.push_back(MachineOperand::CreateImm(Branch.CCValid));
Cond.push_back(MachineOperand::CreateImm(Branch.CCMask));
continue;
}
// Handle subsequent conditional branches.
- assert(Cond.size() == 1);
- assert(TBB);
+ assert(Cond.size() == 2 && TBB && "Should have seen a conditional branch");
// Only handle the case where all conditional branches branch to the same
// destination.
return true;
// If the conditions are the same, we can leave them alone.
- unsigned OldCond = Cond[0].getImm();
- if (OldCond == Branch.CCMask)
+ unsigned OldCCValid = Cond[0].getImm();
+ unsigned OldCCMask = Cond[1].getImm();
+ if (OldCCValid == Branch.CCValid && OldCCMask == Branch.CCMask)
continue;
// FIXME: Try combining conditions like X86 does. Should be easy on Z!
+ return false;
}
return false;
return Count;
}
+bool SystemZInstrInfo::
+ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
+ assert(Cond.size() == 2 && "Invalid condition");
+ Cond[1].setImm(Cond[1].getImm() ^ Cond[0].getImm());
+ return false;
+}
+
unsigned
SystemZInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
- assert((Cond.size() == 1 || Cond.size() == 0) &&
+ assert((Cond.size() == 2 || Cond.size() == 0) &&
"SystemZ branch conditions have one component!");
if (Cond.empty()) {
// Conditional branch.
unsigned Count = 0;
- unsigned CC = Cond[0].getImm();
- BuildMI(&MBB, DL, get(SystemZ::BRC)).addImm(CC).addMBB(TBB);
+ unsigned CCValid = Cond[0].getImm();
+ unsigned CCMask = Cond[1].getImm();
+ BuildMI(&MBB, DL, get(SystemZ::BRC))
+ .addImm(CCValid).addImm(CCMask).addMBB(TBB);
++Count;
if (FBB) {
return Count;
}
+bool SystemZInstrInfo::analyzeCompare(const MachineInstr *MI,
+ unsigned &SrcReg, unsigned &SrcReg2,
+ int &Mask, int &Value) const {
+ assert(MI->isCompare() && "Caller should have checked for a comparison");
+
+ if (MI->getNumExplicitOperands() == 2 &&
+ MI->getOperand(0).isReg() &&
+ MI->getOperand(1).isImm()) {
+ SrcReg = MI->getOperand(0).getReg();
+ SrcReg2 = 0;
+ Value = MI->getOperand(1).getImm();
+ Mask = ~0;
+ return true;
+ }
+
+ return false;
+}
+
+// If Reg is a virtual register that is used by only a single non-debug
+// instruction, return the defining instruction, otherwise return null.
+static MachineInstr *getDefSingleUse(const MachineRegisterInfo *MRI,
+ unsigned Reg) {
+ if (TargetRegisterInfo::isPhysicalRegister(Reg))
+ return 0;
+
+ MachineRegisterInfo::use_nodbg_iterator I = MRI->use_nodbg_begin(Reg);
+ MachineRegisterInfo::use_nodbg_iterator E = MRI->use_nodbg_end();
+ if (I == E || llvm::next(I) != E)
+ return 0;
+
+ return MRI->getUniqueVRegDef(Reg);
+}
+
+// Return true if MI is a shift of type Opcode by Imm bits.
+static bool isShift(MachineInstr *MI, int Opcode, int64_t Imm) {
+ return (MI->getOpcode() == Opcode &&
+ !MI->getOperand(2).getReg() &&
+ MI->getOperand(3).getImm() == Imm);
+}
+
+// Compare compares SrcReg against zero. Check whether SrcReg contains
+// the result of an IPM sequence that is only used by Compare. Try to
+// delete both of them if so and return true if a change was made.
+static bool removeIPM(MachineInstr *Compare, unsigned SrcReg,
+ const MachineRegisterInfo *MRI,
+ const TargetRegisterInfo *TRI) {
+ MachineInstr *SRA = getDefSingleUse(MRI, SrcReg);
+ if (!SRA || !isShift(SRA, SystemZ::SRA, 30))
+ return false;
+
+ MachineInstr *SLL = getDefSingleUse(MRI, SRA->getOperand(1).getReg());
+ if (!SLL || !isShift(SLL, SystemZ::SLL, 2))
+ return false;
+
+ MachineInstr *IPM = getDefSingleUse(MRI, SLL->getOperand(1).getReg());
+ if (!IPM || IPM->getOpcode() != SystemZ::IPM)
+ return false;
+
+ // Check that there are no assignments to CC between the IPM and Compare,
+ // except for the SRA that we'd like to delete. We can ignore SLL because
+ // it does not assign to CC. We can also ignore uses of the SRA CC result,
+ // since it is effectively restoring CC to the value it had before IPM
+ // (for all current use cases).
+ if (IPM->getParent() != Compare->getParent())
+ return false;
+ MachineBasicBlock::iterator MBBI = IPM, MBBE = Compare;
+ for (++MBBI; MBBI != MBBE; ++MBBI) {
+ MachineInstr *MI = MBBI;
+ if (MI != SRA && MI->modifiesRegister(SystemZ::CC, TRI))
+ return false;
+ }
+
+ IPM->eraseFromParent();
+ SLL->eraseFromParent();
+ SRA->eraseFromParent();
+ Compare->eraseFromParent();
+ return true;
+}
+
+bool
+SystemZInstrInfo::optimizeCompareInstr(MachineInstr *Compare,
+ unsigned SrcReg, unsigned SrcReg2,
+ int Mask, int Value,
+ const MachineRegisterInfo *MRI) const {
+ assert(!SrcReg2 && "Only optimizing constant comparisons so far");
+ bool IsLogical = (Compare->getDesc().TSFlags & SystemZII::IsLogical) != 0;
+ if (Value == 0 &&
+ !IsLogical &&
+ removeIPM(Compare, SrcReg, MRI, TM.getRegisterInfo()))
+ return true;
+ return false;
+}
+
+// If Opcode is a move that has a conditional variant, return that variant,
+// otherwise return 0.
+static unsigned getConditionalMove(unsigned Opcode) {
+ switch (Opcode) {
+ case SystemZ::LR: return SystemZ::LOCR;
+ case SystemZ::LGR: return SystemZ::LOCGR;
+ default: return 0;
+ }
+}
+
+bool SystemZInstrInfo::isPredicable(MachineInstr *MI) const {
+ unsigned Opcode = MI->getOpcode();
+ if (TM.getSubtargetImpl()->hasLoadStoreOnCond() &&
+ getConditionalMove(Opcode))
+ return true;
+ return false;
+}
+
+bool SystemZInstrInfo::
+isProfitableToIfCvt(MachineBasicBlock &MBB,
+ unsigned NumCycles, unsigned ExtraPredCycles,
+ const BranchProbability &Probability) const {
+ // For now only convert single instructions.
+ return NumCycles == 1;
+}
+
+bool SystemZInstrInfo::
+isProfitableToIfCvt(MachineBasicBlock &TMBB,
+ unsigned NumCyclesT, unsigned ExtraPredCyclesT,
+ MachineBasicBlock &FMBB,
+ unsigned NumCyclesF, unsigned ExtraPredCyclesF,
+ const BranchProbability &Probability) const {
+ // For now avoid converting mutually-exclusive cases.
+ return false;
+}
+
+bool SystemZInstrInfo::
+PredicateInstruction(MachineInstr *MI,
+ const SmallVectorImpl<MachineOperand> &Pred) const {
+ assert(Pred.size() == 2 && "Invalid condition");
+ unsigned CCValid = Pred[0].getImm();
+ unsigned CCMask = Pred[1].getImm();
+ assert(CCMask > 0 && CCMask < 15 && "Invalid predicate");
+ unsigned Opcode = MI->getOpcode();
+ if (TM.getSubtargetImpl()->hasLoadStoreOnCond()) {
+ if (unsigned CondOpcode = getConditionalMove(Opcode)) {
+ MI->setDesc(get(CondOpcode));
+ MachineInstrBuilder(*MI->getParent()->getParent(), MI)
+ .addImm(CCValid).addImm(CCMask)
+ .addReg(SystemZ::CC, RegState::Implicit);;
+ return true;
+ }
+ }
+ return false;
+}
+
void
SystemZInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MBBI, DebugLoc DL,
MI->getOperand(3).getReg() == 0);
}
-// Return a MachineMemOperand for FrameIndex with flags MMOFlags.
-// Offset is the byte offset from the start of FrameIndex.
-static MachineMemOperand *getFrameMMO(MachineFunction &MF, int FrameIndex,
- uint64_t &Offset, unsigned MMOFlags) {
- const MachineFrameInfo *MFI = MF.getFrameInfo();
- const Value *V = PseudoSourceValue::getFixedStack(FrameIndex);
- return MF.getMachineMemOperand(MachinePointerInfo(V, Offset), MMOFlags,
- MFI->getObjectSize(FrameIndex),
- MFI->getObjectAlignment(FrameIndex));
+namespace {
+ struct LogicOp {
+ LogicOp() : RegSize(0), ImmLSB(0), ImmSize(0) {}
+ LogicOp(unsigned regSize, unsigned immLSB, unsigned immSize)
+ : RegSize(regSize), ImmLSB(immLSB), ImmSize(immSize) {}
+
+ operator bool() const { return RegSize; }
+
+ unsigned RegSize, ImmLSB, ImmSize;
+ };
+}
+
+static LogicOp interpretAndImmediate(unsigned Opcode) {
+ switch (Opcode) {
+ case SystemZ::NILL32: return LogicOp(32, 0, 16);
+ case SystemZ::NILH32: return LogicOp(32, 16, 16);
+ case SystemZ::NILL: return LogicOp(64, 0, 16);
+ case SystemZ::NILH: return LogicOp(64, 16, 16);
+ case SystemZ::NIHL: return LogicOp(64, 32, 16);
+ case SystemZ::NIHH: return LogicOp(64, 48, 16);
+ case SystemZ::NILF32: return LogicOp(32, 0, 32);
+ case SystemZ::NILF: return LogicOp(64, 0, 32);
+ case SystemZ::NIHF: return LogicOp(64, 32, 32);
+ default: return LogicOp();
+ }
+}
+
+// Used to return from convertToThreeAddress after replacing two-address
+// instruction OldMI with three-address instruction NewMI.
+static MachineInstr *finishConvertToThreeAddress(MachineInstr *OldMI,
+ MachineInstr *NewMI,
+ LiveVariables *LV) {
+ if (LV) {
+ unsigned NumOps = OldMI->getNumOperands();
+ for (unsigned I = 1; I < NumOps; ++I) {
+ MachineOperand &Op = OldMI->getOperand(I);
+ if (Op.isReg() && Op.isKill())
+ LV->replaceKillInstruction(Op.getReg(), OldMI, NewMI);
+ }
+ }
+ return NewMI;
+}
+
+MachineInstr *
+SystemZInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
+ MachineBasicBlock::iterator &MBBI,
+ LiveVariables *LV) const {
+ MachineInstr *MI = MBBI;
+ MachineBasicBlock *MBB = MI->getParent();
+
+ unsigned Opcode = MI->getOpcode();
+ unsigned NumOps = MI->getNumOperands();
+
+ // Try to convert something like SLL into SLLK, if supported.
+ // We prefer to keep the two-operand form where possible both
+ // because it tends to be shorter and because some instructions
+ // have memory forms that can be used during spilling.
+ if (TM.getSubtargetImpl()->hasDistinctOps()) {
+ int ThreeOperandOpcode = SystemZ::getThreeOperandOpcode(Opcode);
+ if (ThreeOperandOpcode >= 0) {
+ MachineOperand &Dest = MI->getOperand(0);
+ MachineOperand &Src = MI->getOperand(1);
+ MachineInstrBuilder MIB =
+ BuildMI(*MBB, MBBI, MI->getDebugLoc(), get(ThreeOperandOpcode))
+ .addOperand(Dest);
+ // Keep the kill state, but drop the tied flag.
+ MIB.addReg(Src.getReg(), getKillRegState(Src.isKill()), Src.getSubReg());
+ // Keep the remaining operands as-is.
+ for (unsigned I = 2; I < NumOps; ++I)
+ MIB.addOperand(MI->getOperand(I));
+ return finishConvertToThreeAddress(MI, MIB, LV);
+ }
+ }
+
+ // Try to convert an AND into an RISBG-type instruction.
+ if (LogicOp And = interpretAndImmediate(Opcode)) {
+ unsigned NewOpcode;
+ if (And.RegSize == 64)
+ NewOpcode = SystemZ::RISBG;
+ else if (TM.getSubtargetImpl()->hasHighWord())
+ NewOpcode = SystemZ::RISBLG32;
+ else
+ // We can't use RISBG for 32-bit operations because it clobbers the
+ // high word of the destination too.
+ NewOpcode = 0;
+ if (NewOpcode) {
+ uint64_t Imm = MI->getOperand(2).getImm() << And.ImmLSB;
+ // AND IMMEDIATE leaves the other bits of the register unchanged.
+ Imm |= allOnes(And.RegSize) & ~(allOnes(And.ImmSize) << And.ImmLSB);
+ unsigned Start, End;
+ if (isRxSBGMask(Imm, And.RegSize, Start, End)) {
+ if (NewOpcode == SystemZ::RISBLG32) {
+ Start &= 31;
+ End &= 31;
+ }
+ MachineOperand &Dest = MI->getOperand(0);
+ MachineOperand &Src = MI->getOperand(1);
+ MachineInstrBuilder MIB =
+ BuildMI(*MBB, MI, MI->getDebugLoc(), get(NewOpcode))
+ .addOperand(Dest).addReg(0)
+ .addReg(Src.getReg(), getKillRegState(Src.isKill()), Src.getSubReg())
+ .addImm(Start).addImm(End + 128).addImm(0);
+ return finishConvertToThreeAddress(MI, MIB, LV);
+ }
+ }
+ }
+ return 0;
}
MachineInstr *
return 0;
unsigned OpNum = Ops[0];
- unsigned Reg = MI->getOperand(OpNum).getReg();
- unsigned RegSize = MF.getRegInfo().getRegClass(Reg)->getSize();
- assert(Size == RegSize && "Invalid size combination");
+ assert(Size == MF.getRegInfo()
+ .getRegClass(MI->getOperand(OpNum).getReg())->getSize() &&
+ "Invalid size combination");
+
+ unsigned Opcode = MI->getOpcode();
+ if (Opcode == SystemZ::LGDR || Opcode == SystemZ::LDGR) {
+ bool Op0IsGPR = (Opcode == SystemZ::LGDR);
+ bool Op1IsGPR = (Opcode == SystemZ::LDGR);
+ // If we're spilling the destination of an LDGR or LGDR, store the
+ // source register instead.
+ if (OpNum == 0) {
+ unsigned StoreOpcode = Op1IsGPR ? SystemZ::STG : SystemZ::STD;
+ return BuildMI(MF, MI->getDebugLoc(), get(StoreOpcode))
+ .addOperand(MI->getOperand(1)).addFrameIndex(FrameIndex)
+ .addImm(0).addReg(0);
+ }
+ // If we're spilling the source of an LDGR or LGDR, load the
+ // destination register instead.
+ if (OpNum == 1) {
+ unsigned LoadOpcode = Op0IsGPR ? SystemZ::LG : SystemZ::LD;
+ unsigned Dest = MI->getOperand(0).getReg();
+ return BuildMI(MF, MI->getDebugLoc(), get(LoadOpcode), Dest)
+ .addFrameIndex(FrameIndex).addImm(0).addReg(0);
+ }
+ }
// Look for cases where the source of a simple store or the destination
// of a simple load is being spilled. Try to use MVC instead.
// not valid in cases where the two memories partially overlap; however,
// that is not a problem here, because we know that one of the memories
// is a full frame index.
- //
- // For now we punt if the load or store is also to a frame index.
- // In that case we might end up eliminating both of them to out-of-range
- // offsets, which might then force the register scavenger to spill two
- // other registers. The backend can only handle one such scavenger spill
- // at a time.
if (OpNum == 0 && MI->hasOneMemOperand()) {
MachineMemOperand *MMO = *MI->memoperands_begin();
if (MMO->getSize() == Size && !MMO->isVolatile()) {
// Handle conversion of loads.
- if (isSimpleBD12Move(MI, SystemZII::SimpleBDXLoad) &&
- !MI->getOperand(1).isFI()) {
- uint64_t Offset = 0;
- MachineMemOperand *FrameMMO = getFrameMMO(MF, FrameIndex, Offset,
- MachineMemOperand::MOStore);
+ if (isSimpleBD12Move(MI, SystemZII::SimpleBDXLoad)) {
return BuildMI(MF, MI->getDebugLoc(), get(SystemZ::MVC))
- .addFrameIndex(FrameIndex).addImm(Offset).addImm(Size)
+ .addFrameIndex(FrameIndex).addImm(0).addImm(Size)
.addOperand(MI->getOperand(1)).addImm(MI->getOperand(2).getImm())
- .addMemOperand(FrameMMO).addMemOperand(MMO);
+ .addMemOperand(MMO);
}
// Handle conversion of stores.
- if (isSimpleBD12Move(MI, SystemZII::SimpleBDXStore) &&
- !MI->getOperand(1).isFI()) {
- uint64_t Offset = 0;
- MachineMemOperand *FrameMMO = getFrameMMO(MF, FrameIndex, Offset,
- MachineMemOperand::MOLoad);
+ if (isSimpleBD12Move(MI, SystemZII::SimpleBDXStore)) {
return BuildMI(MF, MI->getDebugLoc(), get(SystemZ::MVC))
.addOperand(MI->getOperand(1)).addImm(MI->getOperand(2).getImm())
- .addImm(Size).addFrameIndex(FrameIndex).addImm(Offset)
- .addMemOperand(MMO).addMemOperand(FrameMMO);
+ .addImm(Size).addFrameIndex(FrameIndex).addImm(0)
+ .addMemOperand(MMO);
}
}
}
+ // If the spilled operand is the final one, try to change <INSN>R
+ // into <INSN>.
+ int MemOpcode = SystemZ::getMemOpcode(Opcode);
+ if (MemOpcode >= 0) {
+ unsigned NumOps = MI->getNumExplicitOperands();
+ if (OpNum == NumOps - 1) {
+ const MCInstrDesc &MemDesc = get(MemOpcode);
+ uint64_t AccessBytes = SystemZII::getAccessSize(MemDesc.TSFlags);
+ assert(AccessBytes != 0 && "Size of access should be known");
+ assert(AccessBytes <= Size && "Access outside the frame index");
+ uint64_t Offset = Size - AccessBytes;
+ MachineInstrBuilder MIB = BuildMI(MF, MI->getDebugLoc(), get(MemOpcode));
+ for (unsigned I = 0; I < OpNum; ++I)
+ MIB.addOperand(MI->getOperand(I));
+ MIB.addFrameIndex(FrameIndex).addImm(Offset);
+ if (MemDesc.TSFlags & SystemZII::HasIndex)
+ MIB.addReg(0);
+ return MIB;
+ }
+ }
+
return 0;
}
}
}
-bool SystemZInstrInfo::
-ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
- assert(Cond.size() == 1 && "Invalid branch condition!");
- Cond[0].setImm(Cond[0].getImm() ^ SystemZ::CCMASK_ANY);
- return false;
-}
-
uint64_t SystemZInstrInfo::getInstSizeInBytes(const MachineInstr *MI) const {
if (MI->getOpcode() == TargetOpcode::INLINEASM) {
const MachineFunction *MF = MI->getParent()->getParent();
case SystemZ::J:
case SystemZ::JG:
return SystemZII::Branch(SystemZII::BranchNormal, SystemZ::CCMASK_ANY,
- &MI->getOperand(0));
+ SystemZ::CCMASK_ANY, &MI->getOperand(0));
case SystemZ::BRC:
case SystemZ::BRCL:
return SystemZII::Branch(SystemZII::BranchNormal,
- MI->getOperand(0).getImm(), &MI->getOperand(1));
+ MI->getOperand(0).getImm(),
+ MI->getOperand(1).getImm(), &MI->getOperand(2));
+
+ case SystemZ::BRCT:
+ return SystemZII::Branch(SystemZII::BranchCT, SystemZ::CCMASK_ICMP,
+ SystemZ::CCMASK_CMP_NE, &MI->getOperand(2));
+
+ case SystemZ::BRCTG:
+ return SystemZII::Branch(SystemZII::BranchCTG, SystemZ::CCMASK_ICMP,
+ SystemZ::CCMASK_CMP_NE, &MI->getOperand(2));
case SystemZ::CIJ:
case SystemZ::CRJ:
- return SystemZII::Branch(SystemZII::BranchC, MI->getOperand(2).getImm(),
- &MI->getOperand(3));
+ return SystemZII::Branch(SystemZII::BranchC, SystemZ::CCMASK_ICMP,
+ MI->getOperand(2).getImm(), &MI->getOperand(3));
case SystemZ::CGIJ:
case SystemZ::CGRJ:
- return SystemZII::Branch(SystemZII::BranchCG, MI->getOperand(2).getImm(),
- &MI->getOperand(3));
+ return SystemZII::Branch(SystemZII::BranchCG, SystemZ::CCMASK_ICMP,
+ MI->getOperand(2).getImm(), &MI->getOperand(3));
default:
llvm_unreachable("Unrecognized branch opcode");
return 0;
}
+unsigned SystemZInstrInfo::getLoadAndTest(unsigned Opcode) const {
+ switch (Opcode) {
+ case SystemZ::L: return SystemZ::LT;
+ case SystemZ::LY: return SystemZ::LT;
+ case SystemZ::LG: return SystemZ::LTG;
+ case SystemZ::LGF: return SystemZ::LTGF;
+ case SystemZ::LR: return SystemZ::LTR;
+ case SystemZ::LGFR: return SystemZ::LTGFR;
+ case SystemZ::LGR: return SystemZ::LTGR;
+ case SystemZ::LER: return SystemZ::LTEBR;
+ case SystemZ::LDR: return SystemZ::LTDBR;
+ case SystemZ::LXR: return SystemZ::LTXBR;
+ default: return 0;
+ }
+}
+
+// Return true if Mask matches the regexp 0*1+0*, given that zero masks
+// have already been filtered out. Store the first set bit in LSB and
+// the number of set bits in Length if so.
+static bool isStringOfOnes(uint64_t Mask, unsigned &LSB, unsigned &Length) {
+ unsigned First = findFirstSet(Mask);
+ uint64_t Top = (Mask >> First) + 1;
+ if ((Top & -Top) == Top) {
+ LSB = First;
+ Length = findFirstSet(Top);
+ return true;
+ }
+ return false;
+}
+
+bool SystemZInstrInfo::isRxSBGMask(uint64_t Mask, unsigned BitSize,
+ unsigned &Start, unsigned &End) const {
+ // Reject trivial all-zero masks.
+ if (Mask == 0)
+ return false;
+
+ // Handle the 1+0+ or 0+1+0* cases. Start then specifies the index of
+ // the msb and End specifies the index of the lsb.
+ unsigned LSB, Length;
+ if (isStringOfOnes(Mask, LSB, Length)) {
+ Start = 63 - (LSB + Length - 1);
+ End = 63 - LSB;
+ return true;
+ }
+
+ // Handle the wrap-around 1+0+1+ cases. Start then specifies the msb
+ // of the low 1s and End specifies the lsb of the high 1s.
+ if (isStringOfOnes(Mask ^ allOnes(BitSize), LSB, Length)) {
+ assert(LSB > 0 && "Bottom bit must be set");
+ assert(LSB + Length < BitSize && "Top bit must be set");
+ Start = 63 - (LSB - 1);
+ End = 63 - (LSB + Length);
+ return true;
+ }
+
+ return false;
+}
+
unsigned SystemZInstrInfo::getCompareAndBranch(unsigned Opcode,
const MachineInstr *MI) const {
switch (Opcode) {
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