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PPCInstrInfo.cpp
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//===-- PPCInstrInfo.cpp - PowerPC Instruction Information ----------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file contains the PowerPC implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "PPCInstrInfo.h"
#include "MCTargetDesc/PPCPredicates.h"
#include "PPC.h"
#include "PPCHazardRecognizers.h"
#include "PPCInstrBuilder.h"
#include "PPCMachineFunctionInfo.h"
#include "PPCTargetMachine.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LiveIntervals.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/CodeGen/ScheduleDAG.h"
#include "llvm/CodeGen/SlotIndexes.h"
#include "llvm/CodeGen/StackMaps.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
#define DEBUG_TYPE "ppc-instr-info"
#define GET_INSTRMAP_INFO
#define GET_INSTRINFO_CTOR_DTOR
#include "PPCGenInstrInfo.inc"
STATISTIC(NumStoreSPILLVSRRCAsVec,
"Number of spillvsrrc spilled to stack as vec");
STATISTIC(NumStoreSPILLVSRRCAsGpr,
"Number of spillvsrrc spilled to stack as gpr");
STATISTIC(NumGPRtoVSRSpill, "Number of gpr spills to spillvsrrc");
STATISTIC(CmpIselsConverted,
"Number of ISELs that depend on comparison of constants converted");
STATISTIC(MissedConvertibleImmediateInstrs,
"Number of compare-immediate instructions fed by constants");
STATISTIC(NumRcRotatesConvertedToRcAnd,
"Number of record-form rotates converted to record-form andi");
static cl::
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);
static cl::opt<bool> VSXSelfCopyCrash("crash-on-ppc-vsx-self-copy",
cl::desc("Causes the backend to crash instead of generating a nop VSX copy"),
cl::Hidden);
static cl::opt<bool>
UseOldLatencyCalc("ppc-old-latency-calc", cl::Hidden,
cl::desc("Use the old (incorrect) instruction latency calculation"));
// Index into the OpcodesForSpill array.
enum SpillOpcodeKey {
SOK_Int4Spill,
SOK_Int8Spill,
SOK_Float8Spill,
SOK_Float4Spill,
SOK_CRSpill,
SOK_CRBitSpill,
SOK_VRVectorSpill,
SOK_VSXVectorSpill,
SOK_VectorFloat8Spill,
SOK_VectorFloat4Spill,
SOK_VRSaveSpill,
SOK_QuadFloat8Spill,
SOK_QuadFloat4Spill,
SOK_QuadBitSpill,
SOK_SpillToVSR,
SOK_SPESpill,
SOK_LastOpcodeSpill // This must be last on the enum.
};
// Pin the vtable to this file.
void PPCInstrInfo::anchor() {}
PPCInstrInfo::PPCInstrInfo(PPCSubtarget &STI)
: PPCGenInstrInfo(PPC::ADJCALLSTACKDOWN, PPC::ADJCALLSTACKUP,
/* CatchRetOpcode */ -1,
STI.isPPC64() ? PPC::BLR8 : PPC::BLR),
Subtarget(STI), RI(STI.getTargetMachine()) {}
/// CreateTargetHazardRecognizer - Return the hazard recognizer to use for
/// this target when scheduling the DAG.
ScheduleHazardRecognizer *
PPCInstrInfo::CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
const ScheduleDAG *DAG) const {
unsigned Directive =
static_cast<const PPCSubtarget *>(STI)->getCPUDirective();
if (Directive == PPC::DIR_440 || Directive == PPC::DIR_A2 ||
Directive == PPC::DIR_E500mc || Directive == PPC::DIR_E5500) {
const InstrItineraryData *II =
static_cast<const PPCSubtarget *>(STI)->getInstrItineraryData();
return new ScoreboardHazardRecognizer(II, DAG);
}
return TargetInstrInfo::CreateTargetHazardRecognizer(STI, DAG);
}
/// CreateTargetPostRAHazardRecognizer - Return the postRA hazard recognizer
/// to use for this target when scheduling the DAG.
ScheduleHazardRecognizer *
PPCInstrInfo::CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
const ScheduleDAG *DAG) const {
unsigned Directive =
DAG->MF.getSubtarget<PPCSubtarget>().getCPUDirective();
// FIXME: Leaving this as-is until we have POWER9 scheduling info
if (Directive == PPC::DIR_PWR7 || Directive == PPC::DIR_PWR8)
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) {
assert(DAG->TII && "No InstrInfo?");
return new PPCHazardRecognizer970(*DAG);
}
return new ScoreboardHazardRecognizer(II, DAG);
}
unsigned PPCInstrInfo::getInstrLatency(const InstrItineraryData *ItinData,
const MachineInstr &MI,
unsigned *PredCost) const {
if (!ItinData || UseOldLatencyCalc)
return PPCGenInstrInfo::getInstrLatency(ItinData, MI, PredCost);
// The default implementation of getInstrLatency calls getStageLatency, but
// getStageLatency does not do the right thing for us. While we have
// itinerary, most cores are fully pipelined, and so the itineraries only
// express the first part of the pipeline, not every stage. Instead, we need
// to use the listed output operand cycle number (using operand 0 here, which
// is an output).
unsigned Latency = 1;
unsigned DefClass = MI.getDesc().getSchedClass();
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI.getOperand(i);
if (!MO.isReg() || !MO.isDef() || MO.isImplicit())
continue;
int Cycle = ItinData->getOperandCycle(DefClass, i);
if (Cycle < 0)
continue;
Latency = std::max(Latency, (unsigned) Cycle);
}
return Latency;
}
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);
if (!DefMI.getParent())
return Latency;
const MachineOperand &DefMO = DefMI.getOperand(DefIdx);
Register Reg = DefMO.getReg();
bool IsRegCR;
if (Register::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 = Subtarget.getCPUDirective();
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:
case PPC::DIR_PWR8:
// FIXME: Is this needed for POWER9?
Latency += 2;
break;
}
}
return Latency;
}
// This function does not list all associative and commutative operations, but
// only those worth feeding through the machine combiner in an attempt to
// reduce the critical path. Mostly, this means floating-point operations,
// because they have high latencies (compared to other operations, such and
// and/or, which are also associative and commutative, but have low latencies).
bool PPCInstrInfo::isAssociativeAndCommutative(const MachineInstr &Inst) const {
switch (Inst.getOpcode()) {
// FP Add:
case PPC::FADD:
case PPC::FADDS:
// FP Multiply:
case PPC::FMUL:
case PPC::FMULS:
// Altivec Add:
case PPC::VADDFP:
// VSX Add:
case PPC::XSADDDP:
case PPC::XVADDDP:
case PPC::XVADDSP:
case PPC::XSADDSP:
// VSX Multiply:
case PPC::XSMULDP:
case PPC::XVMULDP:
case PPC::XVMULSP:
case PPC::XSMULSP:
// QPX Add:
case PPC::QVFADD:
case PPC::QVFADDS:
case PPC::QVFADDSs:
// QPX Multiply:
case PPC::QVFMUL:
case PPC::QVFMULS:
case PPC::QVFMULSs:
return true;
default:
return false;
}
}
bool PPCInstrInfo::getMachineCombinerPatterns(
MachineInstr &Root,
SmallVectorImpl<MachineCombinerPattern> &Patterns) const {
// Using the machine combiner in this way is potentially expensive, so
// restrict to when aggressive optimizations are desired.
if (Subtarget.getTargetMachine().getOptLevel() != CodeGenOpt::Aggressive)
return false;
// FP reassociation is only legal when we don't need strict IEEE semantics.
if (!Root.getParent()->getParent()->getTarget().Options.UnsafeFPMath)
return false;
return TargetInstrInfo::getMachineCombinerPatterns(Root, Patterns);
}
// Detect 32 -> 64-bit extensions where we may reuse the low sub-register.
bool PPCInstrInfo::isCoalescableExtInstr(const MachineInstr &MI,
Register &SrcReg, Register &DstReg,
unsigned &SubIdx) const {
switch (MI.getOpcode()) {
default: return false;
case PPC::EXTSW:
case PPC::EXTSW_32:
case PPC::EXTSW_32_64:
SrcReg = MI.getOperand(1).getReg();
DstReg = MI.getOperand(0).getReg();
SubIdx = PPC::sub_32;
return true;
}
}
unsigned PPCInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
unsigned Opcode = MI.getOpcode();
const unsigned *OpcodesForSpill = getLoadOpcodesForSpillArray();
const unsigned *End = OpcodesForSpill + SOK_LastOpcodeSpill;
if (End != std::find(OpcodesForSpill, End, Opcode)) {
// Check for the operands added by addFrameReference (the immediate is the
// offset which defaults to 0).
if (MI.getOperand(1).isImm() && !MI.getOperand(1).getImm() &&
MI.getOperand(2).isFI()) {
FrameIndex = MI.getOperand(2).getIndex();
return MI.getOperand(0).getReg();
}
}
return 0;
}
// For opcodes with the ReMaterializable flag set, this function is called to
// verify the instruction is really rematable.
bool PPCInstrInfo::isReallyTriviallyReMaterializable(const MachineInstr &MI,
AliasAnalysis *AA) const {
switch (MI.getOpcode()) {
default:
// This function should only be called for opcodes with the ReMaterializable
// flag set.
llvm_unreachable("Unknown rematerializable operation!");
break;
case PPC::LI:
case PPC::LI8:
case PPC::LIS:
case PPC::LIS8:
case PPC::QVGPCI:
case PPC::ADDIStocHA:
case PPC::ADDIStocHA8:
case PPC::ADDItocL:
case PPC::LOAD_STACK_GUARD:
case PPC::XXLXORz:
case PPC::XXLXORspz:
case PPC::XXLXORdpz:
case PPC::XXLEQVOnes:
case PPC::V_SET0B:
case PPC::V_SET0H:
case PPC::V_SET0:
case PPC::V_SETALLONESB:
case PPC::V_SETALLONESH:
case PPC::V_SETALLONES:
case PPC::CRSET:
case PPC::CRUNSET:
return true;
}
return false;
}
unsigned PPCInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
int &FrameIndex) const {
unsigned Opcode = MI.getOpcode();
const unsigned *OpcodesForSpill = getStoreOpcodesForSpillArray();
const unsigned *End = OpcodesForSpill + SOK_LastOpcodeSpill;
if (End != std::find(OpcodesForSpill, End, Opcode)) {
if (MI.getOperand(1).isImm() && !MI.getOperand(1).getImm() &&
MI.getOperand(2).isFI()) {
FrameIndex = MI.getOperand(2).getIndex();
return MI.getOperand(0).getReg();
}
}
return 0;
}
MachineInstr *PPCInstrInfo::commuteInstructionImpl(MachineInstr &MI, bool NewMI,
unsigned OpIdx1,
unsigned OpIdx2) const {
MachineFunction &MF = *MI.getParent()->getParent();
// Normal instructions can be commuted the obvious way.
if (MI.getOpcode() != PPC::RLWIMI && MI.getOpcode() != PPC::RLWIMI_rec)
return TargetInstrInfo::commuteInstructionImpl(MI, NewMI, OpIdx1, OpIdx2);
// Note that RLWIMI can be commuted as a 32-bit instruction, but not as a
// 64-bit instruction (so we don't handle PPC::RLWIMI8 here), because
// changing the relative order of the mask operands might change what happens
// to the high-bits of the mask (and, thus, the result).
// Cannot commute if it has a non-zero rotate count.
if (MI.getOperand(3).getImm() != 0)
return nullptr;
// If we have a zero rotate count, we have:
// M = mask(MB,ME)
// Op0 = (Op1 & ~M) | (Op2 & M)
// Change this to:
// M = mask((ME+1)&31, (MB-1)&31)
// Op0 = (Op2 & ~M) | (Op1 & M)
// Swap op1/op2
assert(((OpIdx1 == 1 && OpIdx2 == 2) || (OpIdx1 == 2 && OpIdx2 == 1)) &&
"Only the operands 1 and 2 can be swapped in RLSIMI/RLWIMI_rec.");
Register Reg0 = MI.getOperand(0).getReg();
Register Reg1 = MI.getOperand(1).getReg();
Register 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;
// If machine instrs are no longer in two-address forms, update
// destination register as well.
if (Reg0 == Reg1) {
// 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;
}
// Masks.
unsigned MB = MI.getOperand(4).getImm();
unsigned ME = MI.getOperand(5).getImm();
// We can't commute a trivial mask (there is no way to represent an all-zero
// mask).
if (MB == 0 && ME == 31)
return nullptr;
if (NewMI) {
// Create a new instruction.
Register Reg0 = ChangeReg0 ? Reg2 : MI.getOperand(0).getReg();
bool Reg0IsDead = MI.getOperand(0).isDead();
return BuildMI(MF, MI.getDebugLoc(), MI.getDesc())
.addReg(Reg0, RegState::Define | getDeadRegState(Reg0IsDead))
.addReg(Reg2, getKillRegState(Reg2IsKill))
.addReg(Reg1, getKillRegState(Reg1IsKill))
.addImm((ME + 1) & 31)
.addImm((MB - 1) & 31);
}
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);
// Swap the mask around.
MI.getOperand(4).setImm((ME + 1) & 31);
MI.getOperand(5).setImm((MB - 1) & 31);
return &MI;
}
bool PPCInstrInfo::findCommutedOpIndices(const MachineInstr &MI,
unsigned &SrcOpIdx1,
unsigned &SrcOpIdx2) const {
// For VSX A-Type FMA instructions, it is the first two operands that can be
// commuted, however, because the non-encoded tied input operand is listed
// first, the operands to swap are actually the second and third.
int AltOpc = PPC::getAltVSXFMAOpcode(MI.getOpcode());
if (AltOpc == -1)
return TargetInstrInfo::findCommutedOpIndices(MI, SrcOpIdx1, SrcOpIdx2);
// The commutable operand indices are 2 and 3. Return them in SrcOpIdx1
// and SrcOpIdx2.
return fixCommutedOpIndices(SrcOpIdx1, SrcOpIdx2, 2, 3);
}
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 = Subtarget.getCPUDirective();
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;
case PPC::DIR_PWR8: Opcode = PPC::NOP_GT_PWR7; break; /* FIXME: Update when P8 InstrScheduling model is ready */
// FIXME: Update when POWER9 scheduling model is ready.
case PPC::DIR_PWR9: Opcode = PPC::NOP_GT_PWR7; break;
}
DebugLoc DL;
BuildMI(MBB, MI, DL, get(Opcode));
}
/// Return the noop instruction to use for a noop.
void PPCInstrInfo::getNoop(MCInst &NopInst) const {
NopInst.setOpcode(PPC::NOP);
}
// 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.
bool PPCInstrInfo::analyzeBranch(MachineBasicBlock &MBB,
MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
bool isPPC64 = Subtarget.isPPC64();
// If the block has no terminators, it just falls into the block after it.
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end())
return false;
if (!isUnpredicatedTerminator(*I))
return false;
if (AllowModify) {
// If the BB ends with an unconditional branch to the fallthrough BB,
// we eliminate the branch instruction.
if (I->getOpcode() == PPC::B &&
MBB.isLayoutSuccessor(I->getOperand(0).getMBB())) {
I->eraseFromParent();
// We update iterator after deleting the last branch.
I = MBB.getLastNonDebugInstr();
if (I == MBB.end() || !isUnpredicatedTerminator(*I))
return false;
}
}
// Get the last instruction in the block.
MachineInstr &LastInst = *I;
// If there is only one terminator instruction, process it.
if (I == MBB.begin() || !isUnpredicatedTerminator(*--I)) {
if (LastInst.getOpcode() == PPC::B) {
if (!LastInst.getOperand(0).isMBB())
return true;
TBB = LastInst.getOperand(0).getMBB();
return false;
} else if (LastInst.getOpcode() == PPC::BCC) {
if (!LastInst.getOperand(2).isMBB())
return true;
// Block ends with fall-through condbranch.
TBB = LastInst.getOperand(2).getMBB();
Cond.push_back(LastInst.getOperand(0));
Cond.push_back(LastInst.getOperand(1));
return false;
} else if (LastInst.getOpcode() == PPC::BC) {
if (!LastInst.getOperand(1).isMBB())
return true;
// Block ends with fall-through condbranch.
TBB = LastInst.getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(PPC::PRED_BIT_SET));
Cond.push_back(LastInst.getOperand(0));
return false;
} else if (LastInst.getOpcode() == PPC::BCn) {
if (!LastInst.getOperand(1).isMBB())
return true;
// Block ends with fall-through condbranch.
TBB = LastInst.getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(PPC::PRED_BIT_UNSET));
Cond.push_back(LastInst.getOperand(0));
return false;
} else if (LastInst.getOpcode() == PPC::BDNZ8 ||
LastInst.getOpcode() == PPC::BDNZ) {
if (!LastInst.getOperand(0).isMBB())
return true;
if (DisableCTRLoopAnal)
return true;
TBB = LastInst.getOperand(0).getMBB();
Cond.push_back(MachineOperand::CreateImm(1));
Cond.push_back(MachineOperand::CreateReg(isPPC64 ? PPC::CTR8 : PPC::CTR,
true));
return false;
} else if (LastInst.getOpcode() == PPC::BDZ8 ||
LastInst.getOpcode() == PPC::BDZ) {
if (!LastInst.getOperand(0).isMBB())
return true;
if (DisableCTRLoopAnal)
return true;
TBB = LastInst.getOperand(0).getMBB();
Cond.push_back(MachineOperand::CreateImm(0));
Cond.push_back(MachineOperand::CreateReg(isPPC64 ? PPC::CTR8 : PPC::CTR,
true));
return false;
}
// Otherwise, don't know what this is.
return true;
}
// Get the instruction before it if it's a terminator.
MachineInstr &SecondLastInst = *I;
// If there are three terminators, we don't know what sort of block this is.
if (I != MBB.begin() && isUnpredicatedTerminator(*--I))
return true;
// If the block ends with PPC::B and PPC:BCC, handle it.
if (SecondLastInst.getOpcode() == PPC::BCC &&
LastInst.getOpcode() == PPC::B) {
if (!SecondLastInst.getOperand(2).isMBB() ||
!LastInst.getOperand(0).isMBB())
return true;
TBB = SecondLastInst.getOperand(2).getMBB();
Cond.push_back(SecondLastInst.getOperand(0));
Cond.push_back(SecondLastInst.getOperand(1));
FBB = LastInst.getOperand(0).getMBB();
return false;
} else if (SecondLastInst.getOpcode() == PPC::BC &&
LastInst.getOpcode() == PPC::B) {
if (!SecondLastInst.getOperand(1).isMBB() ||
!LastInst.getOperand(0).isMBB())
return true;
TBB = SecondLastInst.getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(PPC::PRED_BIT_SET));
Cond.push_back(SecondLastInst.getOperand(0));
FBB = LastInst.getOperand(0).getMBB();
return false;
} else if (SecondLastInst.getOpcode() == PPC::BCn &&
LastInst.getOpcode() == PPC::B) {
if (!SecondLastInst.getOperand(1).isMBB() ||
!LastInst.getOperand(0).isMBB())
return true;
TBB = SecondLastInst.getOperand(1).getMBB();
Cond.push_back(MachineOperand::CreateImm(PPC::PRED_BIT_UNSET));
Cond.push_back(SecondLastInst.getOperand(0));
FBB = LastInst.getOperand(0).getMBB();
return false;
} else if ((SecondLastInst.getOpcode() == PPC::BDNZ8 ||
SecondLastInst.getOpcode() == PPC::BDNZ) &&
LastInst.getOpcode() == PPC::B) {
if (!SecondLastInst.getOperand(0).isMBB() ||
!LastInst.getOperand(0).isMBB())
return true;
if (DisableCTRLoopAnal)
return true;
TBB = SecondLastInst.getOperand(0).getMBB();
Cond.push_back(MachineOperand::CreateImm(1));
Cond.push_back(MachineOperand::CreateReg(isPPC64 ? PPC::CTR8 : PPC::CTR,
true));
FBB = LastInst.getOperand(0).getMBB();
return false;
} else if ((SecondLastInst.getOpcode() == PPC::BDZ8 ||
SecondLastInst.getOpcode() == PPC::BDZ) &&
LastInst.getOpcode() == PPC::B) {
if (!SecondLastInst.getOperand(0).isMBB() ||
!LastInst.getOperand(0).isMBB())
return true;
if (DisableCTRLoopAnal)
return true;
TBB = SecondLastInst.getOperand(0).getMBB();
Cond.push_back(MachineOperand::CreateImm(0));
Cond.push_back(MachineOperand::CreateReg(isPPC64 ? PPC::CTR8 : PPC::CTR,
true));
FBB = LastInst.getOperand(0).getMBB();
return false;
}
// If the block ends with two PPC:Bs, handle it. The second one is not
// executed, so remove it.
if (SecondLastInst.getOpcode() == PPC::B && LastInst.getOpcode() == PPC::B) {
if (!SecondLastInst.getOperand(0).isMBB())
return true;
TBB = SecondLastInst.getOperand(0).getMBB();
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return false;
}
// Otherwise, can't handle this.
return true;
}
unsigned PPCInstrInfo::removeBranch(MachineBasicBlock &MBB,
int *BytesRemoved) const {
assert(!BytesRemoved && "code size not handled");
MachineBasicBlock::iterator I = MBB.getLastNonDebugInstr();
if (I == MBB.end())
return 0;
if (I->getOpcode() != PPC::B && I->getOpcode() != PPC::BCC &&
I->getOpcode() != PPC::BC && I->getOpcode() != PPC::BCn &&
I->getOpcode() != PPC::BDNZ8 && I->getOpcode() != PPC::BDNZ &&
I->getOpcode() != PPC::BDZ8 && I->getOpcode() != PPC::BDZ)
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return 1;
--I;
if (I->getOpcode() != PPC::BCC &&
I->getOpcode() != PPC::BC && I->getOpcode() != PPC::BCn &&
I->getOpcode() != PPC::BDNZ8 && I->getOpcode() != PPC::BDNZ &&
I->getOpcode() != PPC::BDZ8 && I->getOpcode() != PPC::BDZ)
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
unsigned PPCInstrInfo::insertBranch(MachineBasicBlock &MBB,
MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
ArrayRef<MachineOperand> Cond,
const DebugLoc &DL,
int *BytesAdded) const {
// Shouldn't be a fall through.
assert(TBB && "insertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 2 || Cond.size() == 0) &&
"PPC branch conditions have two components!");
assert(!BytesAdded && "code size not handled");
bool isPPC64 = Subtarget.isPPC64();
// One-way branch.
if (!FBB) {
if (Cond.empty()) // Unconditional branch
BuildMI(&MBB, DL, get(PPC::B)).addMBB(TBB);
else if (Cond[1].getReg() == PPC::CTR || Cond[1].getReg() == PPC::CTR8)
BuildMI(&MBB, DL, get(Cond[0].getImm() ?
(isPPC64 ? PPC::BDNZ8 : PPC::BDNZ) :
(isPPC64 ? PPC::BDZ8 : PPC::BDZ))).addMBB(TBB);
else if (Cond[0].getImm() == PPC::PRED_BIT_SET)
BuildMI(&MBB, DL, get(PPC::BC)).add(Cond[1]).addMBB(TBB);
else if (Cond[0].getImm() == PPC::PRED_BIT_UNSET)
BuildMI(&MBB, DL, get(PPC::BCn)).add(Cond[1]).addMBB(TBB);
else // Conditional branch
BuildMI(&MBB, DL, get(PPC::BCC))
.addImm(Cond[0].getImm())
.add(Cond[1])
.addMBB(TBB);
return 1;
}
// Two-way Conditional Branch.
if (Cond[1].getReg() == PPC::CTR || Cond[1].getReg() == PPC::CTR8)
BuildMI(&MBB, DL, get(Cond[0].getImm() ?
(isPPC64 ? PPC::BDNZ8 : PPC::BDNZ) :
(isPPC64 ? PPC::BDZ8 : PPC::BDZ))).addMBB(TBB);
else if (Cond[0].getImm() == PPC::PRED_BIT_SET)
BuildMI(&MBB, DL, get(PPC::BC)).add(Cond[1]).addMBB(TBB);
else if (Cond[0].getImm() == PPC::PRED_BIT_UNSET)
BuildMI(&MBB, DL, get(PPC::BCn)).add(Cond[1]).addMBB(TBB);
else
BuildMI(&MBB, DL, get(PPC::BCC))
.addImm(Cond[0].getImm())
.add(Cond[1])
.addMBB(TBB);
BuildMI(&MBB, DL, get(PPC::B)).addMBB(FBB);
return 2;
}
// Select analysis.
bool PPCInstrInfo::canInsertSelect(const MachineBasicBlock &MBB,
ArrayRef<MachineOperand> Cond,
Register DstReg, Register TrueReg,
Register FalseReg, int &CondCycles,
int &TrueCycles, int &FalseCycles) const {
if (Cond.size() != 2)
return false;
// If this is really a bdnz-like condition, then it cannot be turned into a
// select.
if (Cond[1].getReg() == PPC::CTR || Cond[1].getReg() == PPC::CTR8)
return false;
// Check register classes.
const MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
const TargetRegisterClass *RC =
RI.getCommonSubClass(MRI.getRegClass(TrueReg), MRI.getRegClass(FalseReg));
if (!RC)
return false;
// isel is for regular integer GPRs only.
if (!PPC::GPRCRegClass.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
// an open question. On the A2, the isel instruction has a 2-cycle latency
// but single-cycle throughput. These numbers are used in combination with
// the MispredictPenalty setting from the active SchedMachineModel.
CondCycles = 1;
TrueCycles = 1;
FalseCycles = 1;
return true;
}
void PPCInstrInfo::insertSelect(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const DebugLoc &dl, Register DestReg,
ArrayRef<MachineOperand> Cond, Register TrueReg,
Register FalseReg) const {
assert(Cond.size() == 2 &&
"PPC branch conditions have two components!");
// Get the register classes.
MachineRegisterInfo &MRI = MBB.getParent()->getRegInfo();
const TargetRegisterClass *RC =
RI.getCommonSubClass(MRI.getRegClass(TrueReg), MRI.getRegClass(FalseReg));
assert(RC && "TrueReg and FalseReg must have overlapping register classes");
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 = Is64Bit ? PPC::ISEL8 : PPC::ISEL;
auto SelectPred = static_cast<PPC::Predicate>(Cond[0].getImm());
unsigned SubIdx = 0;
bool SwapOps = false;
switch (SelectPred) {
case PPC::PRED_EQ:
case PPC::PRED_EQ_MINUS:
case PPC::PRED_EQ_PLUS:
SubIdx = PPC::sub_eq; SwapOps = false; break;
case PPC::PRED_NE:
case PPC::PRED_NE_MINUS:
case PPC::PRED_NE_PLUS:
SubIdx = PPC::sub_eq; SwapOps = true; break;
case PPC::PRED_LT:
case PPC::PRED_LT_MINUS:
case PPC::PRED_LT_PLUS:
SubIdx = PPC::sub_lt; SwapOps = false; break;
case PPC::PRED_GE:
case PPC::PRED_GE_MINUS:
case PPC::PRED_GE_PLUS:
SubIdx = PPC::sub_lt; SwapOps = true; break;
case PPC::PRED_GT:
case PPC::PRED_GT_MINUS:
case PPC::PRED_GT_PLUS:
SubIdx = PPC::sub_gt; SwapOps = false; break;
case PPC::PRED_LE:
case PPC::PRED_LE_MINUS:
case PPC::PRED_LE_PLUS:
SubIdx = PPC::sub_gt; SwapOps = true; break;
case PPC::PRED_UN:
case PPC::PRED_UN_MINUS:
case PPC::PRED_UN_PLUS:
SubIdx = PPC::sub_un; SwapOps = false; break;
case PPC::PRED_NU:
case PPC::PRED_NU_MINUS:
case PPC::PRED_NU_PLUS:
SubIdx = PPC::sub_un; SwapOps = true; break;
case PPC::PRED_BIT_SET: SubIdx = 0; SwapOps = false; break;
case PPC::PRED_BIT_UNSET: SubIdx = 0; SwapOps = true; break;
}
Register FirstReg = SwapOps ? FalseReg : TrueReg,
SecondReg = SwapOps ? TrueReg : FalseReg;
// The first input register of isel cannot be r0. If it is a member
// of a register class that can be r0, then copy it first (the
// register allocator should eliminate the copy).
if (MRI.getRegClass(FirstReg)->contains(PPC::R0) ||
MRI.getRegClass(FirstReg)->contains(PPC::X0)) {
const TargetRegisterClass *FirstRC =
MRI.getRegClass(FirstReg)->contains(PPC::X0) ?
&PPC::G8RC_NOX0RegClass : &PPC::GPRC_NOR0RegClass;
Register OldFirstReg = FirstReg;
FirstReg = MRI.createVirtualRegister(FirstRC);
BuildMI(MBB, MI, dl, get(TargetOpcode::COPY), FirstReg)
.addReg(OldFirstReg);
}
BuildMI(MBB, MI, dl, get(OpCode), DestReg)
.addReg(FirstReg).addReg(SecondReg)
.addReg(Cond[1].getReg(), 0, SubIdx);
}
static unsigned getCRBitValue(unsigned CRBit) {
unsigned Ret = 4;
if (CRBit == PPC::CR0LT || CRBit == PPC::CR1LT ||
CRBit == PPC::CR2LT || CRBit == PPC::CR3LT ||
CRBit == PPC::CR4LT || CRBit == PPC::CR5LT ||
CRBit == PPC::CR6LT || CRBit == PPC::CR7LT)
Ret = 3;
if (CRBit == PPC::CR0GT || CRBit == PPC::CR1GT ||
CRBit == PPC::CR2GT || CRBit == PPC::CR3GT ||
CRBit == PPC::CR4GT || CRBit == PPC::CR5GT ||
CRBit == PPC::CR6GT || CRBit == PPC::CR7GT)
Ret = 2;
if (CRBit == PPC::CR0EQ || CRBit == PPC::CR1EQ ||
CRBit == PPC::CR2EQ || CRBit == PPC::CR3EQ ||
CRBit == PPC::CR4EQ || CRBit == PPC::CR5EQ ||
CRBit == PPC::CR6EQ || CRBit == PPC::CR7EQ)
Ret = 1;
if (CRBit == PPC::CR0UN || CRBit == PPC::CR1UN ||
CRBit == PPC::CR2UN || CRBit == PPC::CR3UN ||
CRBit == PPC::CR4UN || CRBit == PPC::CR5UN ||
CRBit == PPC::CR6UN || CRBit == PPC::CR7UN)
Ret = 0;
assert(Ret != 4 && "Invalid CR bit register");
return Ret;
}
void PPCInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
const DebugLoc &DL, MCRegister DestReg,
MCRegister SrcReg, bool KillSrc) const {
// We can end up with self copies and similar things as a result of VSX copy
// legalization. Promote them here.
const TargetRegisterInfo *TRI = &getRegisterInfo();
if (PPC::F8RCRegClass.contains(DestReg) &&
PPC::VSRCRegClass.contains(SrcReg)) {
MCRegister SuperReg =
TRI->getMatchingSuperReg(DestReg, PPC::sub_64, &PPC::VSRCRegClass);
if (VSXSelfCopyCrash && SrcReg == SuperReg)
llvm_unreachable("nop VSX copy");
DestReg = SuperReg;
} else if (PPC::F8RCRegClass.contains(SrcReg) &&
PPC::VSRCRegClass.contains(DestReg)) {
MCRegister SuperReg =
TRI->getMatchingSuperReg(SrcReg, PPC::sub_64, &PPC::VSRCRegClass);
if (VSXSelfCopyCrash && DestReg == SuperReg)
llvm_unreachable("nop VSX copy");
SrcReg = SuperReg;
}
// Different class register copy
if (PPC::CRBITRCRegClass.contains(SrcReg) &&
PPC::GPRCRegClass.contains(DestReg)) {
MCRegister CRReg = getCRFromCRBit(SrcReg);
BuildMI(MBB, I, DL, get(PPC::MFOCRF), DestReg).addReg(CRReg);
getKillRegState(KillSrc);
// Rotate the CR bit in the CR fields to be the least significant bit and
// then mask with 0x1 (MB = ME = 31).
BuildMI(MBB, I, DL, get(PPC::RLWINM), DestReg)
.addReg(DestReg, RegState::Kill)
.addImm(TRI->getEncodingValue(CRReg) * 4 + (4 - getCRBitValue(SrcReg)))
.addImm(31)
.addImm(31);
return;
} else if (PPC::CRRCRegClass.contains(SrcReg) &&
PPC::G8RCRegClass.contains(DestReg)) {
BuildMI(MBB, I, DL, get(PPC::MFOCRF8), DestReg).addReg(SrcReg);
getKillRegState(KillSrc);
return;
} else if (PPC::CRRCRegClass.contains(SrcReg) &&
PPC::GPRCRegClass.contains(DestReg)) {
BuildMI(MBB, I, DL, get(PPC::MFOCRF), DestReg).addReg(SrcReg);
getKillRegState(KillSrc);
return;
} else if (PPC::G8RCRegClass.contains(SrcReg) &&
PPC::VSFRCRegClass.contains(DestReg)) {
assert(Subtarget.hasDirectMove() &&
"Subtarget doesn't support directmove, don't know how to copy.");
BuildMI(MBB, I, DL, get(PPC::MTVSRD), DestReg).addReg(SrcReg);
NumGPRtoVSRSpill++;
getKillRegState(KillSrc);
return;
} else if (PPC::VSFRCRegClass.contains(SrcReg) &&
PPC::G8RCRegClass.contains(DestReg)) {
assert(Subtarget.hasDirectMove() &&
"Subtarget doesn't support directmove, don't know how to copy.");
BuildMI(MBB, I, DL, get(PPC::MFVSRD), DestReg).addReg(SrcReg);
getKillRegState(KillSrc);
return;
} else if (PPC::SPERCRegClass.contains(SrcReg) &&
PPC::GPRCRegClass.contains(DestReg)) {
BuildMI(MBB, I, DL, get(PPC::EFSCFD), DestReg).addReg(SrcReg);
getKillRegState(KillSrc);
return;
} else if (PPC::GPRCRegClass.contains(SrcReg) &&
PPC::SPERCRegClass.contains(DestReg)) {
BuildMI(MBB, I, DL, get(PPC::EFDCFS), DestReg).addReg(SrcReg);
getKillRegState(KillSrc);
return;
}
unsigned Opc;
if (PPC::GPRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::OR;
else if (PPC::G8RCRegClass.contains(DestReg, SrcReg))
Opc = PPC::OR8;
else if (PPC::F4RCRegClass.contains(DestReg, SrcReg))
Opc = PPC::FMR;
else if (PPC::CRRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::MCRF;
else if (PPC::VRRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::VOR;
else if (PPC::VSRCRegClass.contains(DestReg, SrcReg))
// There are two different ways this can be done:
// 1. xxlor : This has lower latency (on the P7), 2 cycles, but can only
// issue in VSU pipeline 0.
// 2. xmovdp/xmovsp: This has higher latency (on the P7), 6 cycles, but
// can go to either pipeline.
// We'll always use xxlor here, because in practically all cases where