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llvm-6502/lib/Target/PowerPC/PPCInstrInfo.cpp
Hal Finkel f8d179ba76 [PowerPC] Add support for the QPX vector instruction set 
This adds support for the QPX vector instruction set, which is used by the
enhanced A2 cores on the IBM BG/Q supercomputers. QPX vectors are 256 bytes
wide, holding 4 double-precision floating-point values. Boolean values, modeled
here as <4 x i1> are actually also represented as floating-point values
(essentially  { -1, 1 } for { false, true }). QPX shares many features with
Altivec and VSX, but is distinct from both of them. One major difference is
that, instead of adding completely-separate vector registers, QPX vector
registers are extensions of the scalar floating-point registers (lane 0 is the
corresponding scalar floating-point value). The operations supported on QPX
vectors mirrors that supported on the scalar floating-point values (with some
additional ones for permutations and logical/comparison operations).

I've been maintaining this support out-of-tree, as part of the bgclang project,
for several years. This is not the entire bgclang patch set, but is most of the
subset that can be cleanly integrated into LLVM proper at this time. Adding
this to the LLVM backend is part of my efforts to rebase bgclang to the current
LLVM trunk, but is independently useful (especially for codes that use LLVM as
a JIT in library form).

The assembler/disassembler test coverage is complete. The CodeGen test coverage
is not, but I've included some tests, and more will be added as follow-up work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230413 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-25 01:06:45 +00:00

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//===-- PPCInstrInfo.cpp - PowerPC Instruction Information ----------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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/LiveIntervalAnalysis.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/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"
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);
// Pin the vtable to this file.
void PPCInstrInfo::anchor() {}
PPCInstrInfo::PPCInstrInfo(PPCSubtarget &STI)
: PPCGenInstrInfo(PPC::ADJCALLSTACKDOWN, PPC::ADJCALLSTACKUP),
Subtarget(STI), RI(STI) {}
/// 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)->getDarwinDirective();
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>().getDarwinDirective();
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);
}
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 = Subtarget.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:
case PPC::DIR_PWR8:
Latency += 2;
break;
}
}
return Latency;
}
// Detect 32 -> 64-bit extensions where we may reuse the low sub-register.
bool PPCInstrInfo::isCoalescableExtInstr(const MachineInstr &MI,
unsigned &SrcReg, unsigned &DstReg,
unsigned &SubIdx) const {
switch (MI.getOpcode()) {
default: return false;
case PPC::EXTSW:
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 {
// Note: This list must be kept consistent with LoadRegFromStackSlot.
switch (MI->getOpcode()) {
default: break;
case PPC::LD:
case PPC::LWZ:
case PPC::LFS:
case PPC::LFD:
case PPC::RESTORE_CR:
case PPC::RESTORE_CRBIT:
case PPC::LVX:
case PPC::LXVD2X:
case PPC::QVLFDX:
case PPC::QVLFSXs:
case PPC::QVLFDXb:
case PPC::RESTORE_VRSAVE:
// 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();
}
break;
}
return 0;
}
unsigned PPCInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
// Note: This list must be kept consistent with StoreRegToStackSlot.
switch (MI->getOpcode()) {
default: break;
case PPC::STD:
case PPC::STW:
case PPC::STFS:
case PPC::STFD:
case PPC::SPILL_CR:
case PPC::SPILL_CRBIT:
case PPC::STVX:
case PPC::STXVD2X:
case PPC::QVSTFDX:
case PPC::QVSTFSXs:
case PPC::QVSTFDXb:
case PPC::SPILL_VRSAVE:
// 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();
}
break;
}
return 0;
}
// commuteInstruction - We can commute rlwimi instructions, but only if the
// rotate amt is zero. We also have to munge the immediates a bit.
MachineInstr *
PPCInstrInfo::commuteInstruction(MachineInstr *MI, bool NewMI) const {
MachineFunction &MF = *MI->getParent()->getParent();
// Normal instructions can be commuted the obvious way.
if (MI->getOpcode() != PPC::RLWIMI &&
MI->getOpcode() != PPC::RLWIMIo)
return TargetInstrInfo::commuteInstruction(MI, NewMI);
// 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
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;
// 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();
if (NewMI) {
// Create a new instruction.
unsigned 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(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);
SrcOpIdx1 = 2;
SrcOpIdx2 = 3;
return true;
}
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.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;
case PPC::DIR_PWR8: Opcode = PPC::NOP_GT_PWR7; break; /* FIXME: Update when P8 InstrScheduling model is ready */
}
DebugLoc DL;
BuildMI(MBB, MI, DL, get(Opcode));
}
/// getNoopForMachoTarget - Return the noop instruction to use for a noop.
void PPCInstrInfo::getNoopForMachoTarget(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.end();
if (I == MBB.begin())
return false;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return false;
--I;
}
if (!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 (SecondLastInst && 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) const {
MachineBasicBlock::iterator I = MBB.end();
if (I == MBB.begin()) return 0;
--I;
while (I->isDebugValue()) {
if (I == MBB.begin())
return 0;
--I;
}
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,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL) 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!");
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)).addOperand(Cond[1]).addMBB(TBB);
else if (Cond[0].getImm() == PPC::PRED_BIT_UNSET)
BuildMI(&MBB, DL, get(PPC::BCn)).addOperand(Cond[1]).addMBB(TBB);
else // Conditional branch
BuildMI(&MBB, DL, get(PPC::BCC))
.addImm(Cond[0].getImm()).addOperand(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)).addOperand(Cond[1]).addMBB(TBB);
else if (Cond[0].getImm() == PPC::PRED_BIT_UNSET)
BuildMI(&MBB, DL, get(PPC::BCn)).addOperand(Cond[1]).addMBB(TBB);
else
BuildMI(&MBB, DL, get(PPC::BCC))
.addImm(Cond[0].getImm()).addOperand(Cond[1]).addMBB(TBB);
BuildMI(&MBB, DL, get(PPC::B)).addMBB(FBB);
return 2;
}
// Select analysis.
bool PPCInstrInfo::canInsertSelect(const MachineBasicBlock &MBB,
const SmallVectorImpl<MachineOperand> &Cond,
unsigned TrueReg, unsigned FalseReg,
int &CondCycles, int &TrueCycles, int &FalseCycles) const {
if (!Subtarget.hasISEL())
return false;
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, DebugLoc dl,
unsigned DestReg,
const SmallVectorImpl<MachineOperand> &Cond,
unsigned TrueReg, unsigned FalseReg) const {
assert(Cond.size() == 2 &&
"PPC branch conditions have two components!");
assert(Subtarget.hasISEL() &&
"Cannot insert select on target without ISEL support");
// 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;
unsigned SelectPred = Cond[0].getImm();
unsigned SubIdx;
bool SwapOps;
switch (SelectPred) {
default: llvm_unreachable("invalid predicate for isel");
case PPC::PRED_EQ: SubIdx = PPC::sub_eq; SwapOps = false; break;
case PPC::PRED_NE: SubIdx = PPC::sub_eq; SwapOps = true; break;
case PPC::PRED_LT: SubIdx = PPC::sub_lt; SwapOps = false; break;
case PPC::PRED_GE: SubIdx = PPC::sub_lt; SwapOps = true; break;
case PPC::PRED_GT: SubIdx = PPC::sub_gt; SwapOps = false; break;
case PPC::PRED_LE: SubIdx = PPC::sub_gt; SwapOps = true; break;
case PPC::PRED_UN: SubIdx = PPC::sub_un; SwapOps = false; break;
case PPC::PRED_NU: 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;
}
unsigned 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;
unsigned 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);
}
void PPCInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned 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)) {
unsigned SuperReg =
TRI->getMatchingSuperReg(DestReg, PPC::sub_64, &PPC::VSRCRegClass);
if (VSXSelfCopyCrash && SrcReg == SuperReg)
llvm_unreachable("nop VSX copy");
DestReg = SuperReg;
} else if (PPC::VRRCRegClass.contains(DestReg) &&
PPC::VSRCRegClass.contains(SrcReg)) {
unsigned SuperReg =
TRI->getMatchingSuperReg(DestReg, PPC::sub_128, &PPC::VSRCRegClass);
if (VSXSelfCopyCrash && SrcReg == SuperReg)
llvm_unreachable("nop VSX copy");
DestReg = SuperReg;
} else if (PPC::F8RCRegClass.contains(SrcReg) &&
PPC::VSRCRegClass.contains(DestReg)) {
unsigned SuperReg =
TRI->getMatchingSuperReg(SrcReg, PPC::sub_64, &PPC::VSRCRegClass);
if (VSXSelfCopyCrash && DestReg == SuperReg)
llvm_unreachable("nop VSX copy");
SrcReg = SuperReg;
} else if (PPC::VRRCRegClass.contains(SrcReg) &&
PPC::VSRCRegClass.contains(DestReg)) {
unsigned SuperReg =
TRI->getMatchingSuperReg(SrcReg, PPC::sub_128, &PPC::VSRCRegClass);
if (VSXSelfCopyCrash && DestReg == SuperReg)
llvm_unreachable("nop VSX copy");
SrcReg = SuperReg;
}
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
// copies are generated, they are close enough to some use that the
// lower-latency form is preferable.
Opc = PPC::XXLOR;
else if (PPC::VSFRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::XXLORf;
else if (PPC::QFRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::QVFMR;
else if (PPC::QSRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::QVFMRs;
else if (PPC::QBRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::QVFMRb;
else if (PPC::CRBITRCRegClass.contains(DestReg, SrcReg))
Opc = PPC::CROR;
else
llvm_unreachable("Impossible reg-to-reg copy");
const MCInstrDesc &MCID = get(Opc);
if (MCID.getNumOperands() == 3)
BuildMI(MBB, I, DL, MCID, DestReg)
.addReg(SrcReg).addReg(SrcReg, getKillRegState(KillSrc));
else
BuildMI(MBB, I, DL, MCID, DestReg).addReg(SrcReg, getKillRegState(KillSrc));
}
// This function returns true if a CR spill is necessary and false otherwise.
bool
PPCInstrInfo::StoreRegToStackSlot(MachineFunction &MF,
unsigned SrcReg, bool isKill,
int FrameIdx,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs,
bool &NonRI, bool &SpillsVRS) const{
// Note: If additional store instructions are added here,
// update isStoreToStackSlot.
DebugLoc DL;
if (PPC::GPRCRegClass.hasSubClassEq(RC) ||
PPC::GPRC_NOR0RegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STW))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
} else if (PPC::G8RCRegClass.hasSubClassEq(RC) ||
PPC::G8RC_NOX0RegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STD))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
} else if (PPC::F8RCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STFD))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
} else if (PPC::F4RCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STFS))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
} else if (PPC::CRRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::SPILL_CR))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
return true;
} else if (PPC::CRBITRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::SPILL_CRBIT))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
return true;
} else if (PPC::VRRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STVX))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
NonRI = true;
} else if (PPC::VSRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STXVD2X))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
NonRI = true;
} else if (PPC::VSFRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::STXSDX))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
NonRI = true;
} else if (PPC::VRSAVERCRegClass.hasSubClassEq(RC)) {
assert(Subtarget.isDarwin() &&
"VRSAVE only needs spill/restore on Darwin");
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::SPILL_VRSAVE))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
SpillsVRS = true;
} else if (PPC::QFRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::QVSTFDX))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
NonRI = true;
} else if (PPC::QSRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::QVSTFSXs))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
NonRI = true;
} else if (PPC::QBRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::QVSTFDXb))
.addReg(SrcReg,
getKillRegState(isKill)),
FrameIdx));
NonRI = true;
} else {
llvm_unreachable("Unknown regclass!");
}
return false;
}
void
PPCInstrInfo::storeRegToStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned SrcReg, bool isKill, int FrameIdx,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
MachineFunction &MF = *MBB.getParent();
SmallVector<MachineInstr*, 4> NewMIs;
PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
FuncInfo->setHasSpills();
bool NonRI = false, SpillsVRS = false;
if (StoreRegToStackSlot(MF, SrcReg, isKill, FrameIdx, RC, NewMIs,
NonRI, SpillsVRS))
FuncInfo->setSpillsCR();
if (SpillsVRS)
FuncInfo->setSpillsVRSAVE();
if (NonRI)
FuncInfo->setHasNonRISpills();
for (unsigned i = 0, e = NewMIs.size(); i != e; ++i)
MBB.insert(MI, NewMIs[i]);
const MachineFrameInfo &MFI = *MF.getFrameInfo();
MachineMemOperand *MMO =
MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FrameIdx),
MachineMemOperand::MOStore,
MFI.getObjectSize(FrameIdx),
MFI.getObjectAlignment(FrameIdx));
NewMIs.back()->addMemOperand(MF, MMO);
}
bool
PPCInstrInfo::LoadRegFromStackSlot(MachineFunction &MF, DebugLoc DL,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
SmallVectorImpl<MachineInstr*> &NewMIs,
bool &NonRI, bool &SpillsVRS) const{
// Note: If additional load instructions are added here,
// update isLoadFromStackSlot.
if (PPC::GPRCRegClass.hasSubClassEq(RC) ||
PPC::GPRC_NOR0RegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LWZ),
DestReg), FrameIdx));
} else if (PPC::G8RCRegClass.hasSubClassEq(RC) ||
PPC::G8RC_NOX0RegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LD), DestReg),
FrameIdx));
} else if (PPC::F8RCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LFD), DestReg),
FrameIdx));
} else if (PPC::F4RCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LFS), DestReg),
FrameIdx));
} else if (PPC::CRRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL,
get(PPC::RESTORE_CR), DestReg),
FrameIdx));
return true;
} else if (PPC::CRBITRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL,
get(PPC::RESTORE_CRBIT), DestReg),
FrameIdx));
return true;
} else if (PPC::VRRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LVX), DestReg),
FrameIdx));
NonRI = true;
} else if (PPC::VSRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LXVD2X), DestReg),
FrameIdx));
NonRI = true;
} else if (PPC::VSFRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::LXSDX), DestReg),
FrameIdx));
NonRI = true;
} else if (PPC::VRSAVERCRegClass.hasSubClassEq(RC)) {
assert(Subtarget.isDarwin() &&
"VRSAVE only needs spill/restore on Darwin");
NewMIs.push_back(addFrameReference(BuildMI(MF, DL,
get(PPC::RESTORE_VRSAVE),
DestReg),
FrameIdx));
SpillsVRS = true;
} else if (PPC::QFRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::QVLFDX), DestReg),
FrameIdx));
NonRI = true;
} else if (PPC::QSRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::QVLFSXs), DestReg),
FrameIdx));
NonRI = true;
} else if (PPC::QBRCRegClass.hasSubClassEq(RC)) {
NewMIs.push_back(addFrameReference(BuildMI(MF, DL, get(PPC::QVLFDXb), DestReg),
FrameIdx));
NonRI = true;
} else {
llvm_unreachable("Unknown regclass!");
}
return false;
}
void
PPCInstrInfo::loadRegFromStackSlot(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
unsigned DestReg, int FrameIdx,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
MachineFunction &MF = *MBB.getParent();
SmallVector<MachineInstr*, 4> NewMIs;
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
FuncInfo->setHasSpills();
bool NonRI = false, SpillsVRS = false;
if (LoadRegFromStackSlot(MF, DL, DestReg, FrameIdx, RC, NewMIs,
NonRI, SpillsVRS))
FuncInfo->setSpillsCR();
if (SpillsVRS)
FuncInfo->setSpillsVRSAVE();
if (NonRI)
FuncInfo->setHasNonRISpills();
for (unsigned i = 0, e = NewMIs.size(); i != e; ++i)
MBB.insert(MI, NewMIs[i]);
const MachineFrameInfo &MFI = *MF.getFrameInfo();
MachineMemOperand *MMO =
MF.getMachineMemOperand(MachinePointerInfo::getFixedStack(FrameIdx),
MachineMemOperand::MOLoad,
MFI.getObjectSize(FrameIdx),
MFI.getObjectAlignment(FrameIdx));
NewMIs.back()->addMemOperand(MF, MMO);
}
bool PPCInstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
assert(Cond.size() == 2 && "Invalid PPC branch opcode!");
if (Cond[1].getReg() == PPC::CTR8 || Cond[1].getReg() == PPC::CTR)
Cond[0].setImm(Cond[0].getImm() == 0 ? 1 : 0);
else
// Leave the CR# the same, but invert the condition.
Cond[0].setImm(PPC::InvertPredicate((PPC::Predicate)Cond[0].getImm()));
return false;
}
bool PPCInstrInfo::FoldImmediate(MachineInstr *UseMI, MachineInstr *DefMI,
unsigned Reg, MachineRegisterInfo *MRI) const {
// For some instructions, it is legal to fold ZERO into the RA register field.
// A zero immediate should always be loaded with a single li.
unsigned DefOpc = DefMI->getOpcode();
if (DefOpc != PPC::LI && DefOpc != PPC::LI8)
return false;
if (!DefMI->getOperand(1).isImm())
return false;
if (DefMI->getOperand(1).getImm() != 0)
return false;
// Note that we cannot here invert the arguments of an isel in order to fold
// a ZERO into what is presented as the second argument. All we have here
// is the condition bit, and that might come from a CR-logical bit operation.
const MCInstrDesc &UseMCID = UseMI->getDesc();
// Only fold into real machine instructions.
if (UseMCID.isPseudo())
return false;
unsigned UseIdx;
for (UseIdx = 0; UseIdx < UseMI->getNumOperands(); ++UseIdx)
if (UseMI->getOperand(UseIdx).isReg() &&
UseMI->getOperand(UseIdx).getReg() == Reg)
break;
assert(UseIdx < UseMI->getNumOperands() && "Cannot find Reg in UseMI");
assert(UseIdx < UseMCID.getNumOperands() && "No operand description for Reg");
const MCOperandInfo *UseInfo = &UseMCID.OpInfo[UseIdx];
// We can fold the zero if this register requires a GPRC_NOR0/G8RC_NOX0
// register (which might also be specified as a pointer class kind).
if (UseInfo->isLookupPtrRegClass()) {
if (UseInfo->RegClass /* Kind */ != 1)
return false;
} else {
if (UseInfo->RegClass != PPC::GPRC_NOR0RegClassID &&
UseInfo->RegClass != PPC::G8RC_NOX0RegClassID)
return false;
}
// Make sure this is not tied to an output register (or otherwise
// constrained). This is true for ST?UX registers, for example, which
// are tied to their output registers.
if (UseInfo->Constraints != 0)
return false;
unsigned ZeroReg;
if (UseInfo->isLookupPtrRegClass()) {
bool isPPC64 = Subtarget.isPPC64();
ZeroReg = isPPC64 ? PPC::ZERO8 : PPC::ZERO;
} else {
ZeroReg = UseInfo->RegClass == PPC::G8RC_NOX0RegClassID ?
PPC::ZERO8 : PPC::ZERO;
}
bool DeleteDef = MRI->hasOneNonDBGUse(Reg);
UseMI->getOperand(UseIdx).setReg(ZeroReg);
if (DeleteDef)
DefMI->eraseFromParent();
return true;
}
static bool MBBDefinesCTR(MachineBasicBlock &MBB) {
for (MachineBasicBlock::iterator I = MBB.begin(), IE = MBB.end();
I != IE; ++I)
if (I->definesRegister(PPC::CTR) || I->definesRegister(PPC::CTR8))
return true;
return false;
}
// We should make sure that, if we're going to predicate both sides of a
// condition (a diamond), that both sides don't define the counter register. We
// can predicate counter-decrement-based branches, but while that predicates
// the branching, it does not predicate the counter decrement. If we tried to
// merge the triangle into one predicated block, we'd decrement the counter
// twice.
bool PPCInstrInfo::isProfitableToIfCvt(MachineBasicBlock &TMBB,
unsigned NumT, unsigned ExtraT,
MachineBasicBlock &FMBB,
unsigned NumF, unsigned ExtraF,
const BranchProbability &Probability) const {
return !(MBBDefinesCTR(TMBB) && MBBDefinesCTR(FMBB));
}
bool PPCInstrInfo::isPredicated(const MachineInstr *MI) const {
// The predicated branches are identified by their type, not really by the
// explicit presence of a predicate. Furthermore, some of them can be
// predicated more than once. Because if conversion won't try to predicate
// any instruction which already claims to be predicated (by returning true
// here), always return false. In doing so, we let isPredicable() be the
// final word on whether not the instruction can be (further) predicated.
return false;
}
bool PPCInstrInfo::isUnpredicatedTerminator(const MachineInstr *MI) const {
if (!MI->isTerminator())
return false;
// Conditional branch is a special case.
if (MI->isBranch() && !MI->isBarrier())
return true;
return !isPredicated(MI);
}
bool PPCInstrInfo::PredicateInstruction(
MachineInstr *MI,
const SmallVectorImpl<MachineOperand> &Pred) const {
unsigned OpC = MI->getOpcode();
if (OpC == PPC::BLR || OpC == PPC::BLR8) {
if (Pred[1].getReg() == PPC::CTR8 || Pred[1].getReg() == PPC::CTR) {
bool isPPC64 = Subtarget.isPPC64();
MI->setDesc(get(Pred[0].getImm() ?
(isPPC64 ? PPC::BDNZLR8 : PPC::BDNZLR) :
(isPPC64 ? PPC::BDZLR8 : PPC::BDZLR)));
} else if (Pred[0].getImm() == PPC::PRED_BIT_SET) {
MI->setDesc(get(PPC::BCLR));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addReg(Pred[1].getReg());
} else if (Pred[0].getImm() == PPC::PRED_BIT_UNSET) {
MI->setDesc(get(PPC::BCLRn));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addReg(Pred[1].getReg());
} else {
MI->setDesc(get(PPC::BCCLR));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addImm(Pred[0].getImm())
.addReg(Pred[1].getReg());
}
return true;
} else if (OpC == PPC::B) {
if (Pred[1].getReg() == PPC::CTR8 || Pred[1].getReg() == PPC::CTR) {
bool isPPC64 = Subtarget.isPPC64();
MI->setDesc(get(Pred[0].getImm() ?
(isPPC64 ? PPC::BDNZ8 : PPC::BDNZ) :
(isPPC64 ? PPC::BDZ8 : PPC::BDZ)));
} else if (Pred[0].getImm() == PPC::PRED_BIT_SET) {
MachineBasicBlock *MBB = MI->getOperand(0).getMBB();
MI->RemoveOperand(0);
MI->setDesc(get(PPC::BC));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addReg(Pred[1].getReg())
.addMBB(MBB);
} else if (Pred[0].getImm() == PPC::PRED_BIT_UNSET) {
MachineBasicBlock *MBB = MI->getOperand(0).getMBB();
MI->RemoveOperand(0);
MI->setDesc(get(PPC::BCn));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addReg(Pred[1].getReg())
.addMBB(MBB);
} else {
MachineBasicBlock *MBB = MI->getOperand(0).getMBB();
MI->RemoveOperand(0);
MI->setDesc(get(PPC::BCC));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addImm(Pred[0].getImm())
.addReg(Pred[1].getReg())
.addMBB(MBB);
}
return true;
} else if (OpC == PPC::BCTR || OpC == PPC::BCTR8 ||
OpC == PPC::BCTRL || OpC == PPC::BCTRL8) {
if (Pred[1].getReg() == PPC::CTR8 || Pred[1].getReg() == PPC::CTR)
llvm_unreachable("Cannot predicate bctr[l] on the ctr register");
bool setLR = OpC == PPC::BCTRL || OpC == PPC::BCTRL8;
bool isPPC64 = Subtarget.isPPC64();
if (Pred[0].getImm() == PPC::PRED_BIT_SET) {
MI->setDesc(get(isPPC64 ? (setLR ? PPC::BCCTRL8 : PPC::BCCTR8) :
(setLR ? PPC::BCCTRL : PPC::BCCTR)));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addReg(Pred[1].getReg());
return true;
} else if (Pred[0].getImm() == PPC::PRED_BIT_UNSET) {
MI->setDesc(get(isPPC64 ? (setLR ? PPC::BCCTRL8n : PPC::BCCTR8n) :
(setLR ? PPC::BCCTRLn : PPC::BCCTRn)));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addReg(Pred[1].getReg());
return true;
}
MI->setDesc(get(isPPC64 ? (setLR ? PPC::BCCCTRL8 : PPC::BCCCTR8) :
(setLR ? PPC::BCCCTRL : PPC::BCCCTR)));
MachineInstrBuilder(*MI->getParent()->getParent(), MI)
.addImm(Pred[0].getImm())
.addReg(Pred[1].getReg());
return true;
}
return false;
}
bool PPCInstrInfo::SubsumesPredicate(
const SmallVectorImpl<MachineOperand> &Pred1,
const SmallVectorImpl<MachineOperand> &Pred2) const {
assert(Pred1.size() == 2 && "Invalid PPC first predicate");
assert(Pred2.size() == 2 && "Invalid PPC second predicate");
if (Pred1[1].getReg() == PPC::CTR8 || Pred1[1].getReg() == PPC::CTR)
return false;
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();
if (P1 == P2)
return true;
// Does P1 subsume P2, e.g. GE subsumes GT.
if (P1 == PPC::PRED_LE &&
(P2 == PPC::PRED_LT || P2 == PPC::PRED_EQ))
return true;
if (P1 == PPC::PRED_GE &&
(P2 == PPC::PRED_GT || P2 == PPC::PRED_EQ))
return true;
return false;
}
bool PPCInstrInfo::DefinesPredicate(MachineInstr *MI,
std::vector<MachineOperand> &Pred) const {
// Note: At the present time, the contents of Pred from this function is
// unused by IfConversion. This implementation follows ARM by pushing the
// CR-defining operand. Because the 'DZ' and 'DNZ' count as types of
// predicate, instructions defining CTR or CTR8 are also included as
// predicate-defining instructions.
const TargetRegisterClass *RCs[] =
{ &PPC::CRRCRegClass, &PPC::CRBITRCRegClass,
&PPC::CTRRCRegClass, &PPC::CTRRC8RegClass };
bool Found = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
for (unsigned c = 0; c < array_lengthof(RCs) && !Found; ++c) {
const TargetRegisterClass *RC = RCs[c];
if (MO.isReg()) {
if (MO.isDef() && RC->contains(MO.getReg())) {
Pred.push_back(MO);
Found = true;
}
} else if (MO.isRegMask()) {
for (TargetRegisterClass::iterator I = RC->begin(),
IE = RC->end(); I != IE; ++I)
if (MO.clobbersPhysReg(*I)) {
Pred.push_back(MO);
Found = true;
}
}
}
}
return Found;
}
bool PPCInstrInfo::isPredicable(MachineInstr *MI) const {
unsigned OpC = MI->getOpcode();
switch (OpC) {
default:
return false;
case PPC::B:
case PPC::BLR:
case PPC::BLR8:
case PPC::BCTR:
case PPC::BCTR8:
case PPC::BCTRL:
case PPC::BCTRL8:
return true;
}
}
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 = Subtarget.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_instr_iterator I =MRI->use_instr_begin(CRReg),
IE = MRI->use_instr_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_instr_iterator J =MRI->use_instr_begin(CRReg),
JE = MRI->use_instr_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 = nullptr;
if (SrcReg2 != 0)
// MI is not a candidate for CMPrr.
MI = nullptr;
// 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_instr_iterator
I = MRI->use_instr_begin(CRReg), IE = MRI->use_instr_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(&(UseMI->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(&(UseMI->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(), std::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.
///
unsigned PPCInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
unsigned Opcode = MI->getOpcode();
if (Opcode == PPC::INLINEASM) {
const MachineFunction *MF = MI->getParent()->getParent();
const char *AsmStr = MI->getOperand(0).getSymbolName();
return getInlineAsmLength(AsmStr, *MF->getTarget().getMCAsmInfo());
} else if (Opcode == TargetOpcode::STACKMAP) {
return MI->getOperand(1).getImm();
} else if (Opcode == TargetOpcode::PATCHPOINT) {
PatchPointOpers Opers(MI);
return Opers.getMetaOper(PatchPointOpers::NBytesPos).getImm();
} else {
const MCInstrDesc &Desc = get(Opcode);
return Desc.getSize();
}
}
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