#include "PPCInstrBuilder.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCTargetMachine.h"
-#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
-#define GET_INSTRINFO_CTOR
+#define GET_INSTRMAP_INFO
+#define GET_INSTRINFO_CTOR_DTOR
#include "PPCGenInstrInfo.inc"
using namespace llvm;
opt<bool> DisableCTRLoopAnal("disable-ppc-ctrloop-analysis", cl::Hidden,
cl::desc("Disable analysis for CTR loops"));
+static cl::opt<bool> DisableCmpOpt("disable-ppc-cmp-opt",
+cl::desc("Disable compare instruction optimization"), cl::Hidden);
+
+// Pin the vtable to this file.
+void PPCInstrInfo::anchor() {}
+
PPCInstrInfo::PPCInstrInfo(PPCTargetMachine &tm)
: PPCGenInstrInfo(PPC::ADJCALLSTACKDOWN, PPC::ADJCALLSTACKUP),
- TM(tm), RI(*TM.getSubtargetImpl(), *this) {}
+ TM(tm), RI(*TM.getSubtargetImpl()) {}
/// CreateTargetHazardRecognizer - Return the hazard recognizer to use for
/// this target when scheduling the DAG.
if (Directive == PPC::DIR_440 || Directive == PPC::DIR_A2 ||
Directive == PPC::DIR_E500mc || Directive == PPC::DIR_E5500) {
const InstrItineraryData *II = TM->getInstrItineraryData();
- return new PPCScoreboardHazardRecognizer(II, DAG);
+ return new ScoreboardHazardRecognizer(II, DAG);
}
return TargetInstrInfo::CreateTargetHazardRecognizer(TM, DAG);
const ScheduleDAG *DAG) const {
unsigned Directive = TM.getSubtarget<PPCSubtarget>().getDarwinDirective();
+ if (Directive == PPC::DIR_PWR7)
+ return new PPCDispatchGroupSBHazardRecognizer(II, DAG);
+
// Most subtargets use a PPC970 recognizer.
if (Directive != PPC::DIR_440 && Directive != PPC::DIR_A2 &&
Directive != PPC::DIR_E500mc && Directive != PPC::DIR_E5500) {
- const TargetInstrInfo *TII = TM.getInstrInfo();
- assert(TII && "No InstrInfo?");
+ assert(TM.getInstrInfo() && "No InstrInfo?");
+
+ return new PPCHazardRecognizer970(TM);
+ }
+
+ return new ScoreboardHazardRecognizer(II, DAG);
+}
+
- return new PPCHazardRecognizer970(*TII);
+int PPCInstrInfo::getOperandLatency(const InstrItineraryData *ItinData,
+ const MachineInstr *DefMI, unsigned DefIdx,
+ const MachineInstr *UseMI,
+ unsigned UseIdx) const {
+ int Latency = PPCGenInstrInfo::getOperandLatency(ItinData, DefMI, DefIdx,
+ UseMI, UseIdx);
+
+ const MachineOperand &DefMO = DefMI->getOperand(DefIdx);
+ unsigned Reg = DefMO.getReg();
+
+ const TargetRegisterInfo *TRI = &getRegisterInfo();
+ bool IsRegCR;
+ if (TRI->isVirtualRegister(Reg)) {
+ const MachineRegisterInfo *MRI =
+ &DefMI->getParent()->getParent()->getRegInfo();
+ IsRegCR = MRI->getRegClass(Reg)->hasSuperClassEq(&PPC::CRRCRegClass) ||
+ MRI->getRegClass(Reg)->hasSuperClassEq(&PPC::CRBITRCRegClass);
+ } else {
+ IsRegCR = PPC::CRRCRegClass.contains(Reg) ||
+ PPC::CRBITRCRegClass.contains(Reg);
+ }
+
+ if (UseMI->isBranch() && IsRegCR) {
+ if (Latency < 0)
+ Latency = getInstrLatency(ItinData, DefMI);
+
+ // On some cores, there is an additional delay between writing to a condition
+ // register, and using it from a branch.
+ unsigned Directive = TM.getSubtarget<PPCSubtarget>().getDarwinDirective();
+ switch (Directive) {
+ default: break;
+ case PPC::DIR_7400:
+ case PPC::DIR_750:
+ case PPC::DIR_970:
+ case PPC::DIR_E5500:
+ case PPC::DIR_PWR4:
+ case PPC::DIR_PWR5:
+ case PPC::DIR_PWR5X:
+ case PPC::DIR_PWR6:
+ case PPC::DIR_PWR6X:
+ case PPC::DIR_PWR7:
+ Latency += 2;
+ break;
+ }
}
- return new PPCScoreboardHazardRecognizer(II, DAG);
+ return Latency;
}
// Detect 32 -> 64-bit extensions where we may reuse the low sub-register.
unsigned Reg0 = MI->getOperand(0).getReg();
unsigned Reg1 = MI->getOperand(1).getReg();
unsigned Reg2 = MI->getOperand(2).getReg();
+ unsigned SubReg1 = MI->getOperand(1).getSubReg();
+ unsigned SubReg2 = MI->getOperand(2).getSubReg();
bool Reg1IsKill = MI->getOperand(1).isKill();
bool Reg2IsKill = MI->getOperand(2).isKill();
bool ChangeReg0 = false;
// Must be two address instruction!
assert(MI->getDesc().getOperandConstraint(0, MCOI::TIED_TO) &&
"Expecting a two-address instruction!");
+ assert(MI->getOperand(0).getSubReg() == SubReg1 && "Tied subreg mismatch");
Reg2IsKill = false;
ChangeReg0 = true;
}
.addImm((MB-1) & 31);
}
- if (ChangeReg0)
+ if (ChangeReg0) {
MI->getOperand(0).setReg(Reg2);
+ MI->getOperand(0).setSubReg(SubReg2);
+ }
MI->getOperand(2).setReg(Reg1);
MI->getOperand(1).setReg(Reg2);
+ MI->getOperand(2).setSubReg(SubReg1);
+ MI->getOperand(1).setSubReg(SubReg2);
MI->getOperand(2).setIsKill(Reg1IsKill);
MI->getOperand(1).setIsKill(Reg2IsKill);
void PPCInstrInfo::insertNoop(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI) const {
+ // This function is used for scheduling, and the nop wanted here is the type
+ // that terminates dispatch groups on the POWER cores.
+ unsigned Directive = TM.getSubtarget<PPCSubtarget>().getDarwinDirective();
+ unsigned Opcode;
+ switch (Directive) {
+ default: Opcode = PPC::NOP; break;
+ case PPC::DIR_PWR6: Opcode = PPC::NOP_GT_PWR6; break;
+ case PPC::DIR_PWR7: Opcode = PPC::NOP_GT_PWR7; break;
+ }
+
DebugLoc DL;
- BuildMI(MBB, MI, DL, get(PPC::NOP));
+ BuildMI(MBB, MI, DL, get(Opcode));
}
-
// Branch analysis.
// Note: If the condition register is set to CTR or CTR8 then this is a
// BDNZ (imm == 1) or BDZ (imm == 0) branch.
// isel is for regular integer GPRs only.
if (!PPC::GPRCRegClass.hasSubClassEq(RC) &&
- !PPC::G8RCRegClass.hasSubClassEq(RC))
+ !PPC::GPRC_NOR0RegClass.hasSubClassEq(RC) &&
+ !PPC::G8RCRegClass.hasSubClassEq(RC) &&
+ !PPC::G8RC_NOX0RegClass.hasSubClassEq(RC))
return false;
// FIXME: These numbers are for the A2, how well they work for other cores is
const TargetRegisterClass *RC =
RI.getCommonSubClass(MRI.getRegClass(TrueReg), MRI.getRegClass(FalseReg));
assert(RC && "TrueReg and FalseReg must have overlapping register classes");
- assert((PPC::GPRCRegClass.hasSubClassEq(RC) ||
- PPC::G8RCRegClass.hasSubClassEq(RC)) &&
+
+ bool Is64Bit = PPC::G8RCRegClass.hasSubClassEq(RC) ||
+ PPC::G8RC_NOX0RegClass.hasSubClassEq(RC);
+ assert((Is64Bit ||
+ PPC::GPRCRegClass.hasSubClassEq(RC) ||
+ PPC::GPRC_NOR0RegClass.hasSubClassEq(RC)) &&
"isel is for regular integer GPRs only");
- unsigned OpCode =
- PPC::GPRCRegClass.hasSubClassEq(RC) ? PPC::ISEL : PPC::ISEL8;
+ unsigned OpCode = Is64Bit ? PPC::ISEL8 : PPC::ISEL;
unsigned SelectPred = Cond[0].getImm();
unsigned SubIdx;
NewMIs.back()->addMemOperand(MF, MMO);
}
-MachineInstr*
-PPCInstrInfo::emitFrameIndexDebugValue(MachineFunction &MF,
- int FrameIx, uint64_t Offset,
- const MDNode *MDPtr,
- DebugLoc DL) const {
- MachineInstrBuilder MIB = BuildMI(MF, DL, get(PPC::DBG_VALUE));
- addFrameReference(MIB, FrameIx, 0, false).addImm(Offset).addMetadata(MDPtr);
- return &*MIB;
-}
-
bool PPCInstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
assert(Cond.size() == 2 && "Invalid PPC branch opcode!");
if (Pred2[1].getReg() == PPC::CTR8 || Pred2[1].getReg() == PPC::CTR)
return false;
+ // P1 can only subsume P2 if they test the same condition register.
+ if (Pred1[1].getReg() != Pred2[1].getReg())
+ return false;
+
PPC::Predicate P1 = (PPC::Predicate) Pred1[0].getImm();
PPC::Predicate P2 = (PPC::Predicate) Pred2[0].getImm();
}
}
+bool PPCInstrInfo::analyzeCompare(const MachineInstr *MI,
+ unsigned &SrcReg, unsigned &SrcReg2,
+ int &Mask, int &Value) const {
+ unsigned Opc = MI->getOpcode();
+
+ switch (Opc) {
+ default: return false;
+ case PPC::CMPWI:
+ case PPC::CMPLWI:
+ case PPC::CMPDI:
+ case PPC::CMPLDI:
+ SrcReg = MI->getOperand(1).getReg();
+ SrcReg2 = 0;
+ Value = MI->getOperand(2).getImm();
+ Mask = 0xFFFF;
+ return true;
+ case PPC::CMPW:
+ case PPC::CMPLW:
+ case PPC::CMPD:
+ case PPC::CMPLD:
+ case PPC::FCMPUS:
+ case PPC::FCMPUD:
+ SrcReg = MI->getOperand(1).getReg();
+ SrcReg2 = MI->getOperand(2).getReg();
+ return true;
+ }
+}
+
+bool PPCInstrInfo::optimizeCompareInstr(MachineInstr *CmpInstr,
+ unsigned SrcReg, unsigned SrcReg2,
+ int Mask, int Value,
+ const MachineRegisterInfo *MRI) const {
+ if (DisableCmpOpt)
+ return false;
+
+ int OpC = CmpInstr->getOpcode();
+ unsigned CRReg = CmpInstr->getOperand(0).getReg();
+
+ // FP record forms set CR1 based on the execption status bits, not a
+ // comparison with zero.
+ if (OpC == PPC::FCMPUS || OpC == PPC::FCMPUD)
+ return false;
+
+ // The record forms set the condition register based on a signed comparison
+ // with zero (so says the ISA manual). This is not as straightforward as it
+ // seems, however, because this is always a 64-bit comparison on PPC64, even
+ // for instructions that are 32-bit in nature (like slw for example).
+ // So, on PPC32, for unsigned comparisons, we can use the record forms only
+ // for equality checks (as those don't depend on the sign). On PPC64,
+ // we are restricted to equality for unsigned 64-bit comparisons and for
+ // signed 32-bit comparisons the applicability is more restricted.
+ bool isPPC64 = TM.getSubtargetImpl()->isPPC64();
+ bool is32BitSignedCompare = OpC == PPC::CMPWI || OpC == PPC::CMPW;
+ bool is32BitUnsignedCompare = OpC == PPC::CMPLWI || OpC == PPC::CMPLW;
+ bool is64BitUnsignedCompare = OpC == PPC::CMPLDI || OpC == PPC::CMPLD;
+
+ // Get the unique definition of SrcReg.
+ MachineInstr *MI = MRI->getUniqueVRegDef(SrcReg);
+ if (!MI) return false;
+ int MIOpC = MI->getOpcode();
+
+ bool equalityOnly = false;
+ bool noSub = false;
+ if (isPPC64) {
+ if (is32BitSignedCompare) {
+ // We can perform this optimization only if MI is sign-extending.
+ if (MIOpC == PPC::SRAW || MIOpC == PPC::SRAWo ||
+ MIOpC == PPC::SRAWI || MIOpC == PPC::SRAWIo ||
+ MIOpC == PPC::EXTSB || MIOpC == PPC::EXTSBo ||
+ MIOpC == PPC::EXTSH || MIOpC == PPC::EXTSHo ||
+ MIOpC == PPC::EXTSW || MIOpC == PPC::EXTSWo) {
+ noSub = true;
+ } else
+ return false;
+ } else if (is32BitUnsignedCompare) {
+ // We can perform this optimization, equality only, if MI is
+ // zero-extending.
+ if (MIOpC == PPC::CNTLZW || MIOpC == PPC::CNTLZWo ||
+ MIOpC == PPC::SLW || MIOpC == PPC::SLWo ||
+ MIOpC == PPC::SRW || MIOpC == PPC::SRWo) {
+ noSub = true;
+ equalityOnly = true;
+ } else
+ return false;
+ } else
+ equalityOnly = is64BitUnsignedCompare;
+ } else
+ equalityOnly = is32BitUnsignedCompare;
+
+ if (equalityOnly) {
+ // We need to check the uses of the condition register in order to reject
+ // non-equality comparisons.
+ for (MachineRegisterInfo::use_iterator I = MRI->use_begin(CRReg),
+ IE = MRI->use_end(); I != IE; ++I) {
+ MachineInstr *UseMI = &*I;
+ if (UseMI->getOpcode() == PPC::BCC) {
+ unsigned Pred = UseMI->getOperand(0).getImm();
+ if (Pred != PPC::PRED_EQ && Pred != PPC::PRED_NE)
+ return false;
+ } else if (UseMI->getOpcode() == PPC::ISEL ||
+ UseMI->getOpcode() == PPC::ISEL8) {
+ unsigned SubIdx = UseMI->getOperand(3).getSubReg();
+ if (SubIdx != PPC::sub_eq)
+ return false;
+ } else
+ return false;
+ }
+ }
+
+ MachineBasicBlock::iterator I = CmpInstr;
+
+ // Scan forward to find the first use of the compare.
+ for (MachineBasicBlock::iterator EL = CmpInstr->getParent()->end();
+ I != EL; ++I) {
+ bool FoundUse = false;
+ for (MachineRegisterInfo::use_iterator J = MRI->use_begin(CRReg),
+ JE = MRI->use_end(); J != JE; ++J)
+ if (&*J == &*I) {
+ FoundUse = true;
+ break;
+ }
+
+ if (FoundUse)
+ break;
+ }
+
+ // There are two possible candidates which can be changed to set CR[01].
+ // One is MI, the other is a SUB instruction.
+ // For CMPrr(r1,r2), we are looking for SUB(r1,r2) or SUB(r2,r1).
+ MachineInstr *Sub = NULL;
+ if (SrcReg2 != 0)
+ // MI is not a candidate for CMPrr.
+ MI = NULL;
+ // FIXME: Conservatively refuse to convert an instruction which isn't in the
+ // same BB as the comparison. This is to allow the check below to avoid calls
+ // (and other explicit clobbers); instead we should really check for these
+ // more explicitly (in at least a few predecessors).
+ else if (MI->getParent() != CmpInstr->getParent() || Value != 0) {
+ // PPC does not have a record-form SUBri.
+ return false;
+ }
+
+ // Search for Sub.
+ const TargetRegisterInfo *TRI = &getRegisterInfo();
+ --I;
+
+ // Get ready to iterate backward from CmpInstr.
+ MachineBasicBlock::iterator E = MI,
+ B = CmpInstr->getParent()->begin();
+
+ for (; I != E && !noSub; --I) {
+ const MachineInstr &Instr = *I;
+ unsigned IOpC = Instr.getOpcode();
+
+ if (&*I != CmpInstr && (
+ Instr.modifiesRegister(PPC::CR0, TRI) ||
+ Instr.readsRegister(PPC::CR0, TRI)))
+ // This instruction modifies or uses the record condition register after
+ // the one we want to change. While we could do this transformation, it
+ // would likely not be profitable. This transformation removes one
+ // instruction, and so even forcing RA to generate one move probably
+ // makes it unprofitable.
+ return false;
+
+ // Check whether CmpInstr can be made redundant by the current instruction.
+ if ((OpC == PPC::CMPW || OpC == PPC::CMPLW ||
+ OpC == PPC::CMPD || OpC == PPC::CMPLD) &&
+ (IOpC == PPC::SUBF || IOpC == PPC::SUBF8) &&
+ ((Instr.getOperand(1).getReg() == SrcReg &&
+ Instr.getOperand(2).getReg() == SrcReg2) ||
+ (Instr.getOperand(1).getReg() == SrcReg2 &&
+ Instr.getOperand(2).getReg() == SrcReg))) {
+ Sub = &*I;
+ break;
+ }
+
+ if (I == B)
+ // The 'and' is below the comparison instruction.
+ return false;
+ }
+
+ // Return false if no candidates exist.
+ if (!MI && !Sub)
+ return false;
+
+ // The single candidate is called MI.
+ if (!MI) MI = Sub;
+
+ int NewOpC = -1;
+ MIOpC = MI->getOpcode();
+ if (MIOpC == PPC::ANDIo || MIOpC == PPC::ANDIo8)
+ NewOpC = MIOpC;
+ else {
+ NewOpC = PPC::getRecordFormOpcode(MIOpC);
+ if (NewOpC == -1 && PPC::getNonRecordFormOpcode(MIOpC) != -1)
+ NewOpC = MIOpC;
+ }
+
+ // FIXME: On the non-embedded POWER architectures, only some of the record
+ // forms are fast, and we should use only the fast ones.
+
+ // The defining instruction has a record form (or is already a record
+ // form). It is possible, however, that we'll need to reverse the condition
+ // code of the users.
+ if (NewOpC == -1)
+ return false;
+
+ SmallVector<std::pair<MachineOperand*, PPC::Predicate>, 4> PredsToUpdate;
+ SmallVector<std::pair<MachineOperand*, unsigned>, 4> SubRegsToUpdate;
+
+ // If we have SUB(r1, r2) and CMP(r2, r1), the condition code based on CMP
+ // needs to be updated to be based on SUB. Push the condition code
+ // operands to OperandsToUpdate. If it is safe to remove CmpInstr, the
+ // condition code of these operands will be modified.
+ bool ShouldSwap = false;
+ if (Sub) {
+ ShouldSwap = SrcReg2 != 0 && Sub->getOperand(1).getReg() == SrcReg2 &&
+ Sub->getOperand(2).getReg() == SrcReg;
+
+ // The operands to subf are the opposite of sub, so only in the fixed-point
+ // case, invert the order.
+ ShouldSwap = !ShouldSwap;
+ }
+
+ if (ShouldSwap)
+ for (MachineRegisterInfo::use_iterator I = MRI->use_begin(CRReg),
+ IE = MRI->use_end(); I != IE; ++I) {
+ MachineInstr *UseMI = &*I;
+ if (UseMI->getOpcode() == PPC::BCC) {
+ PPC::Predicate Pred = (PPC::Predicate) UseMI->getOperand(0).getImm();
+ assert((!equalityOnly ||
+ Pred == PPC::PRED_EQ || Pred == PPC::PRED_NE) &&
+ "Invalid predicate for equality-only optimization");
+ PredsToUpdate.push_back(std::make_pair(&((*I).getOperand(0)),
+ PPC::getSwappedPredicate(Pred)));
+ } else if (UseMI->getOpcode() == PPC::ISEL ||
+ UseMI->getOpcode() == PPC::ISEL8) {
+ unsigned NewSubReg = UseMI->getOperand(3).getSubReg();
+ assert((!equalityOnly || NewSubReg == PPC::sub_eq) &&
+ "Invalid CR bit for equality-only optimization");
+
+ if (NewSubReg == PPC::sub_lt)
+ NewSubReg = PPC::sub_gt;
+ else if (NewSubReg == PPC::sub_gt)
+ NewSubReg = PPC::sub_lt;
+
+ SubRegsToUpdate.push_back(std::make_pair(&((*I).getOperand(3)),
+ NewSubReg));
+ } else // We need to abort on a user we don't understand.
+ return false;
+ }
+
+ // Create a new virtual register to hold the value of the CR set by the
+ // record-form instruction. If the instruction was not previously in
+ // record form, then set the kill flag on the CR.
+ CmpInstr->eraseFromParent();
+
+ MachineBasicBlock::iterator MII = MI;
+ BuildMI(*MI->getParent(), llvm::next(MII), MI->getDebugLoc(),
+ get(TargetOpcode::COPY), CRReg)
+ .addReg(PPC::CR0, MIOpC != NewOpC ? RegState::Kill : 0);
+
+ if (MIOpC != NewOpC) {
+ // We need to be careful here: we're replacing one instruction with
+ // another, and we need to make sure that we get all of the right
+ // implicit uses and defs. On the other hand, the caller may be holding
+ // an iterator to this instruction, and so we can't delete it (this is
+ // specifically the case if this is the instruction directly after the
+ // compare).
+
+ const MCInstrDesc &NewDesc = get(NewOpC);
+ MI->setDesc(NewDesc);
+
+ if (NewDesc.ImplicitDefs)
+ for (const uint16_t *ImpDefs = NewDesc.getImplicitDefs();
+ *ImpDefs; ++ImpDefs)
+ if (!MI->definesRegister(*ImpDefs))
+ MI->addOperand(*MI->getParent()->getParent(),
+ MachineOperand::CreateReg(*ImpDefs, true, true));
+ if (NewDesc.ImplicitUses)
+ for (const uint16_t *ImpUses = NewDesc.getImplicitUses();
+ *ImpUses; ++ImpUses)
+ if (!MI->readsRegister(*ImpUses))
+ MI->addOperand(*MI->getParent()->getParent(),
+ MachineOperand::CreateReg(*ImpUses, false, true));
+ }
+
+ // Modify the condition code of operands in OperandsToUpdate.
+ // Since we have SUB(r1, r2) and CMP(r2, r1), the condition code needs to
+ // be changed from r2 > r1 to r1 < r2, from r2 < r1 to r1 > r2, etc.
+ for (unsigned i = 0, e = PredsToUpdate.size(); i < e; i++)
+ PredsToUpdate[i].first->setImm(PredsToUpdate[i].second);
+
+ for (unsigned i = 0, e = SubRegsToUpdate.size(); i < e; i++)
+ SubRegsToUpdate[i].first->setSubReg(SubRegsToUpdate[i].second);
+
+ return true;
+}
+
/// GetInstSize - Return the number of bytes of code the specified
/// instruction may be. This returns the maximum number of bytes.
///
if (J->getOpcode() == PPC::B) {
if (J->getOperand(0).getMBB() == &ReturnMBB) {
// This is an unconditional branch to the return. Replace the
- // branch with a blr.
+ // branch with a blr.
BuildMI(**PI, J, J->getDebugLoc(), TII->get(PPC::BLR));
MachineBasicBlock::iterator K = J--;
K->eraseFromParent();
if ((*PI)->canFallThrough() && (*PI)->isLayoutSuccessor(&ReturnMBB))
OtherReference = true;
- // Predecessors are stored in a vector and can't be removed here.
+ // Predecessors are stored in a vector and can't be removed here.
if (!OtherReference && BlockChanged) {
PredToRemove.push_back(*PI);
}
return Changed;
for (MachineFunction::iterator I = MF.begin(); I != MF.end();) {
- MachineBasicBlock &B = *I++;
+ MachineBasicBlock &B = *I++;
if (processBlock(B))
Changed = true;
}
char PPCEarlyReturn::ID = 0;
FunctionPass*
llvm::createPPCEarlyReturnPass() { return new PPCEarlyReturn(); }
-
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