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llvm-6502/lib/Target/ARM/ARMBaseInstrInfo.cpp
Bill Wendling ad422718f9 Minor simplification. Gets rid of a needless temporary. 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111430 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-18 21:32:07 +00:00

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//===- ARMBaseInstrInfo.cpp - ARM Instruction Information -------*- C++ -*-===//
//
// 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 Base ARM implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//
#include "ARMBaseInstrInfo.h"
#include "ARM.h"
#include "ARMAddressingModes.h"
#include "ARMConstantPoolValue.h"
#include "ARMMachineFunctionInfo.h"
#include "ARMRegisterInfo.h"
#include "ARMGenInstrInfo.inc"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/GlobalValue.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineConstantPool.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineJumpTableInfo.h"
#include "llvm/CodeGen/MachineMemOperand.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/PseudoSourceValue.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm;
static cl::opt<bool>
EnableARM3Addr("enable-arm-3-addr-conv", cl::Hidden,
cl::desc("Enable ARM 2-addr to 3-addr conv"));
ARMBaseInstrInfo::ARMBaseInstrInfo(const ARMSubtarget& STI)
: TargetInstrInfoImpl(ARMInsts, array_lengthof(ARMInsts)),
Subtarget(STI) {
}
MachineInstr *
ARMBaseInstrInfo::convertToThreeAddress(MachineFunction::iterator &MFI,
MachineBasicBlock::iterator &MBBI,
LiveVariables *LV) const {
// FIXME: Thumb2 support.
if (!EnableARM3Addr)
return NULL;
MachineInstr *MI = MBBI;
MachineFunction &MF = *MI->getParent()->getParent();
uint64_t TSFlags = MI->getDesc().TSFlags;
bool isPre = false;
switch ((TSFlags & ARMII::IndexModeMask) >> ARMII::IndexModeShift) {
default: return NULL;
case ARMII::IndexModePre:
isPre = true;
break;
case ARMII::IndexModePost:
break;
}
// Try splitting an indexed load/store to an un-indexed one plus an add/sub
// operation.
unsigned MemOpc = getUnindexedOpcode(MI->getOpcode());
if (MemOpc == 0)
return NULL;
MachineInstr *UpdateMI = NULL;
MachineInstr *MemMI = NULL;
unsigned AddrMode = (TSFlags & ARMII::AddrModeMask);
const TargetInstrDesc &TID = MI->getDesc();
unsigned NumOps = TID.getNumOperands();
bool isLoad = !TID.mayStore();
const MachineOperand &WB = isLoad ? MI->getOperand(1) : MI->getOperand(0);
const MachineOperand &Base = MI->getOperand(2);
const MachineOperand &Offset = MI->getOperand(NumOps-3);
unsigned WBReg = WB.getReg();
unsigned BaseReg = Base.getReg();
unsigned OffReg = Offset.getReg();
unsigned OffImm = MI->getOperand(NumOps-2).getImm();
ARMCC::CondCodes Pred = (ARMCC::CondCodes)MI->getOperand(NumOps-1).getImm();
switch (AddrMode) {
default:
assert(false && "Unknown indexed op!");
return NULL;
case ARMII::AddrMode2: {
bool isSub = ARM_AM::getAM2Op(OffImm) == ARM_AM::sub;
unsigned Amt = ARM_AM::getAM2Offset(OffImm);
if (OffReg == 0) {
if (ARM_AM::getSOImmVal(Amt) == -1)
// Can't encode it in a so_imm operand. This transformation will
// add more than 1 instruction. Abandon!
return NULL;
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
.addReg(BaseReg).addImm(Amt)
.addImm(Pred).addReg(0).addReg(0);
} else if (Amt != 0) {
ARM_AM::ShiftOpc ShOpc = ARM_AM::getAM2ShiftOpc(OffImm);
unsigned SOOpc = ARM_AM::getSORegOpc(ShOpc, Amt);
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBrs : ARM::ADDrs), WBReg)
.addReg(BaseReg).addReg(OffReg).addReg(0).addImm(SOOpc)
.addImm(Pred).addReg(0).addReg(0);
} else
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
.addReg(BaseReg).addReg(OffReg)
.addImm(Pred).addReg(0).addReg(0);
break;
}
case ARMII::AddrMode3 : {
bool isSub = ARM_AM::getAM3Op(OffImm) == ARM_AM::sub;
unsigned Amt = ARM_AM::getAM3Offset(OffImm);
if (OffReg == 0)
// Immediate is 8-bits. It's guaranteed to fit in a so_imm operand.
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBri : ARM::ADDri), WBReg)
.addReg(BaseReg).addImm(Amt)
.addImm(Pred).addReg(0).addReg(0);
else
UpdateMI = BuildMI(MF, MI->getDebugLoc(),
get(isSub ? ARM::SUBrr : ARM::ADDrr), WBReg)
.addReg(BaseReg).addReg(OffReg)
.addImm(Pred).addReg(0).addReg(0);
break;
}
}
std::vector<MachineInstr*> NewMIs;
if (isPre) {
if (isLoad)
MemMI = BuildMI(MF, MI->getDebugLoc(),
get(MemOpc), MI->getOperand(0).getReg())
.addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
else
MemMI = BuildMI(MF, MI->getDebugLoc(),
get(MemOpc)).addReg(MI->getOperand(1).getReg())
.addReg(WBReg).addReg(0).addImm(0).addImm(Pred);
NewMIs.push_back(MemMI);
NewMIs.push_back(UpdateMI);
} else {
if (isLoad)
MemMI = BuildMI(MF, MI->getDebugLoc(),
get(MemOpc), MI->getOperand(0).getReg())
.addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
else
MemMI = BuildMI(MF, MI->getDebugLoc(),
get(MemOpc)).addReg(MI->getOperand(1).getReg())
.addReg(BaseReg).addReg(0).addImm(0).addImm(Pred);
if (WB.isDead())
UpdateMI->getOperand(0).setIsDead();
NewMIs.push_back(UpdateMI);
NewMIs.push_back(MemMI);
}
// Transfer LiveVariables states, kill / dead info.
if (LV) {
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (MO.isReg() && MO.getReg() &&
TargetRegisterInfo::isVirtualRegister(MO.getReg())) {
unsigned Reg = MO.getReg();
LiveVariables::VarInfo &VI = LV->getVarInfo(Reg);
if (MO.isDef()) {
MachineInstr *NewMI = (Reg == WBReg) ? UpdateMI : MemMI;
if (MO.isDead())
LV->addVirtualRegisterDead(Reg, NewMI);
}
if (MO.isUse() && MO.isKill()) {
for (unsigned j = 0; j < 2; ++j) {
// Look at the two new MI's in reverse order.
MachineInstr *NewMI = NewMIs[j];
if (!NewMI->readsRegister(Reg))
continue;
LV->addVirtualRegisterKilled(Reg, NewMI);
if (VI.removeKill(MI))
VI.Kills.push_back(NewMI);
break;
}
}
}
}
}
MFI->insert(MBBI, NewMIs[1]);
MFI->insert(MBBI, NewMIs[0]);
return NewMIs[0];
}
bool
ARMBaseInstrInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
MachineBasicBlock::iterator MI,
const std::vector<CalleeSavedInfo> &CSI,
const TargetRegisterInfo *TRI) const {
if (CSI.empty())
return false;
DebugLoc DL;
if (MI != MBB.end()) DL = MI->getDebugLoc();
for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
unsigned Reg = CSI[i].getReg();
bool isKill = true;
// Add the callee-saved register as live-in unless it's LR and
// @llvm.returnaddress is called. If LR is returned for @llvm.returnaddress
// then it's already added to the function and entry block live-in sets.
if (Reg == ARM::LR) {
MachineFunction &MF = *MBB.getParent();
if (MF.getFrameInfo()->isReturnAddressTaken() &&
MF.getRegInfo().isLiveIn(Reg))
isKill = false;
}
if (isKill)
MBB.addLiveIn(Reg);
// Insert the spill to the stack frame. The register is killed at the spill
//
const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
storeRegToStackSlot(MBB, MI, Reg, isKill,
CSI[i].getFrameIdx(), RC, TRI);
}
return true;
}
// Branch analysis.
bool
ARMBaseInstrInfo::AnalyzeBranch(MachineBasicBlock &MBB,MachineBasicBlock *&TBB,
MachineBasicBlock *&FBB,
SmallVectorImpl<MachineOperand> &Cond,
bool AllowModify) const {
// 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.
unsigned LastOpc = LastInst->getOpcode();
if (I == MBB.begin() || !isUnpredicatedTerminator(--I)) {
if (isUncondBranchOpcode(LastOpc)) {
TBB = LastInst->getOperand(0).getMBB();
return false;
}
if (isCondBranchOpcode(LastOpc)) {
// Block ends with fall-through condbranch.
TBB = LastInst->getOperand(0).getMBB();
Cond.push_back(LastInst->getOperand(1));
Cond.push_back(LastInst->getOperand(2));
return false;
}
return true; // Can't handle indirect branch.
}
// Get the instruction before it if it is a terminator.
MachineInstr *SecondLastInst = I;
// If there are three terminators, we don't know what sort of block this is.
if (SecondLastInst && I != MBB.begin() && isUnpredicatedTerminator(--I))
return true;
// If the block ends with a B and a Bcc, handle it.
unsigned SecondLastOpc = SecondLastInst->getOpcode();
if (isCondBranchOpcode(SecondLastOpc) && isUncondBranchOpcode(LastOpc)) {
TBB = SecondLastInst->getOperand(0).getMBB();
Cond.push_back(SecondLastInst->getOperand(1));
Cond.push_back(SecondLastInst->getOperand(2));
FBB = LastInst->getOperand(0).getMBB();
return false;
}
// If the block ends with two unconditional branches, handle it. The second
// one is not executed, so remove it.
if (isUncondBranchOpcode(SecondLastOpc) && isUncondBranchOpcode(LastOpc)) {
TBB = SecondLastInst->getOperand(0).getMBB();
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return false;
}
// ...likewise if it ends with a branch table followed by an unconditional
// branch. The branch folder can create these, and we must get rid of them for
// correctness of Thumb constant islands.
if ((isJumpTableBranchOpcode(SecondLastOpc) ||
isIndirectBranchOpcode(SecondLastOpc)) &&
isUncondBranchOpcode(LastOpc)) {
I = LastInst;
if (AllowModify)
I->eraseFromParent();
return true;
}
// Otherwise, can't handle this.
return true;
}
unsigned ARMBaseInstrInfo::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 (!isUncondBranchOpcode(I->getOpcode()) &&
!isCondBranchOpcode(I->getOpcode()))
return 0;
// Remove the branch.
I->eraseFromParent();
I = MBB.end();
if (I == MBB.begin()) return 1;
--I;
if (!isCondBranchOpcode(I->getOpcode()))
return 1;
// Remove the branch.
I->eraseFromParent();
return 2;
}
unsigned
ARMBaseInstrInfo::InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
MachineBasicBlock *FBB,
const SmallVectorImpl<MachineOperand> &Cond,
DebugLoc DL) const {
ARMFunctionInfo *AFI = MBB.getParent()->getInfo<ARMFunctionInfo>();
int BOpc = !AFI->isThumbFunction()
? ARM::B : (AFI->isThumb2Function() ? ARM::t2B : ARM::tB);
int BccOpc = !AFI->isThumbFunction()
? ARM::Bcc : (AFI->isThumb2Function() ? ARM::t2Bcc : ARM::tBcc);
// Shouldn't be a fall through.
assert(TBB && "InsertBranch must not be told to insert a fallthrough");
assert((Cond.size() == 2 || Cond.size() == 0) &&
"ARM branch conditions have two components!");
if (FBB == 0) {
if (Cond.empty()) // Unconditional branch?
BuildMI(&MBB, DL, get(BOpc)).addMBB(TBB);
else
BuildMI(&MBB, DL, get(BccOpc)).addMBB(TBB)
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
return 1;
}
// Two-way conditional branch.
BuildMI(&MBB, DL, get(BccOpc)).addMBB(TBB)
.addImm(Cond[0].getImm()).addReg(Cond[1].getReg());
BuildMI(&MBB, DL, get(BOpc)).addMBB(FBB);
return 2;
}
bool ARMBaseInstrInfo::
ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const {
ARMCC::CondCodes CC = (ARMCC::CondCodes)(int)Cond[0].getImm();
Cond[0].setImm(ARMCC::getOppositeCondition(CC));
return false;
}
bool ARMBaseInstrInfo::
PredicateInstruction(MachineInstr *MI,
const SmallVectorImpl<MachineOperand> &Pred) const {
unsigned Opc = MI->getOpcode();
if (isUncondBranchOpcode(Opc)) {
MI->setDesc(get(getMatchingCondBranchOpcode(Opc)));
MI->addOperand(MachineOperand::CreateImm(Pred[0].getImm()));
MI->addOperand(MachineOperand::CreateReg(Pred[1].getReg(), false));
return true;
}
int PIdx = MI->findFirstPredOperandIdx();
if (PIdx != -1) {
MachineOperand &PMO = MI->getOperand(PIdx);
PMO.setImm(Pred[0].getImm());
MI->getOperand(PIdx+1).setReg(Pred[1].getReg());
return true;
}
return false;
}
bool ARMBaseInstrInfo::
SubsumesPredicate(const SmallVectorImpl<MachineOperand> &Pred1,
const SmallVectorImpl<MachineOperand> &Pred2) const {
if (Pred1.size() > 2 || Pred2.size() > 2)
return false;
ARMCC::CondCodes CC1 = (ARMCC::CondCodes)Pred1[0].getImm();
ARMCC::CondCodes CC2 = (ARMCC::CondCodes)Pred2[0].getImm();
if (CC1 == CC2)
return true;
switch (CC1) {
default:
return false;
case ARMCC::AL:
return true;
case ARMCC::HS:
return CC2 == ARMCC::HI;
case ARMCC::LS:
return CC2 == ARMCC::LO || CC2 == ARMCC::EQ;
case ARMCC::GE:
return CC2 == ARMCC::GT;
case ARMCC::LE:
return CC2 == ARMCC::LT;
}
}
bool ARMBaseInstrInfo::DefinesPredicate(MachineInstr *MI,
std::vector<MachineOperand> &Pred) const {
// FIXME: This confuses implicit_def with optional CPSR def.
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.getImplicitDefs() && !TID.hasOptionalDef())
return false;
bool Found = false;
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
const MachineOperand &MO = MI->getOperand(i);
if (MO.isReg() && MO.getReg() == ARM::CPSR) {
Pred.push_back(MO);
Found = true;
}
}
return Found;
}
/// isPredicable - Return true if the specified instruction can be predicated.
/// By default, this returns true for every instruction with a
/// PredicateOperand.
bool ARMBaseInstrInfo::isPredicable(MachineInstr *MI) const {
const TargetInstrDesc &TID = MI->getDesc();
if (!TID.isPredicable())
return false;
if ((TID.TSFlags & ARMII::DomainMask) == ARMII::DomainNEON) {
ARMFunctionInfo *AFI =
MI->getParent()->getParent()->getInfo<ARMFunctionInfo>();
return AFI->isThumb2Function();
}
return true;
}
/// FIXME: Works around a gcc miscompilation with -fstrict-aliasing.
DISABLE_INLINE
static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
unsigned JTI);
static unsigned getNumJTEntries(const std::vector<MachineJumpTableEntry> &JT,
unsigned JTI) {
assert(JTI < JT.size());
return JT[JTI].MBBs.size();
}
/// GetInstSize - Return the size of the specified MachineInstr.
///
unsigned ARMBaseInstrInfo::GetInstSizeInBytes(const MachineInstr *MI) const {
const MachineBasicBlock &MBB = *MI->getParent();
const MachineFunction *MF = MBB.getParent();
const MCAsmInfo *MAI = MF->getTarget().getMCAsmInfo();
// Basic size info comes from the TSFlags field.
const TargetInstrDesc &TID = MI->getDesc();
uint64_t TSFlags = TID.TSFlags;
unsigned Opc = MI->getOpcode();
switch ((TSFlags & ARMII::SizeMask) >> ARMII::SizeShift) {
default: {
// If this machine instr is an inline asm, measure it.
if (MI->getOpcode() == ARM::INLINEASM)
return getInlineAsmLength(MI->getOperand(0).getSymbolName(), *MAI);
if (MI->isLabel())
return 0;
switch (Opc) {
default:
llvm_unreachable("Unknown or unset size field for instr!");
case TargetOpcode::IMPLICIT_DEF:
case TargetOpcode::KILL:
case TargetOpcode::PROLOG_LABEL:
case TargetOpcode::EH_LABEL:
case TargetOpcode::DBG_VALUE:
return 0;
}
break;
}
case ARMII::Size8Bytes: return 8; // ARM instruction x 2.
case ARMII::Size4Bytes: return 4; // ARM / Thumb2 instruction.
case ARMII::Size2Bytes: return 2; // Thumb1 instruction.
case ARMII::SizeSpecial: {
switch (Opc) {
case ARM::CONSTPOOL_ENTRY:
// If this machine instr is a constant pool entry, its size is recorded as
// operand #2.
return MI->getOperand(2).getImm();
case ARM::Int_eh_sjlj_longjmp:
return 16;
case ARM::tInt_eh_sjlj_longjmp:
return 10;
case ARM::Int_eh_sjlj_setjmp:
case ARM::Int_eh_sjlj_setjmp_nofp:
return 20;
case ARM::tInt_eh_sjlj_setjmp:
case ARM::t2Int_eh_sjlj_setjmp:
case ARM::t2Int_eh_sjlj_setjmp_nofp:
return 12;
case ARM::BR_JTr:
case ARM::BR_JTm:
case ARM::BR_JTadd:
case ARM::tBR_JTr:
case ARM::t2BR_JT:
case ARM::t2TBB:
case ARM::t2TBH: {
// These are jumptable branches, i.e. a branch followed by an inlined
// jumptable. The size is 4 + 4 * number of entries. For TBB, each
// entry is one byte; TBH two byte each.
unsigned EntrySize = (Opc == ARM::t2TBB)
? 1 : ((Opc == ARM::t2TBH) ? 2 : 4);
unsigned NumOps = TID.getNumOperands();
MachineOperand JTOP =
MI->getOperand(NumOps - (TID.isPredicable() ? 3 : 2));
unsigned JTI = JTOP.getIndex();
const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
assert(MJTI != 0);
const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
assert(JTI < JT.size());
// Thumb instructions are 2 byte aligned, but JT entries are 4 byte
// 4 aligned. The assembler / linker may add 2 byte padding just before
// the JT entries. The size does not include this padding; the
// constant islands pass does separate bookkeeping for it.
// FIXME: If we know the size of the function is less than (1 << 16) *2
// bytes, we can use 16-bit entries instead. Then there won't be an
// alignment issue.
unsigned InstSize = (Opc == ARM::tBR_JTr || Opc == ARM::t2BR_JT) ? 2 : 4;
unsigned NumEntries = getNumJTEntries(JT, JTI);
if (Opc == ARM::t2TBB && (NumEntries & 1))
// Make sure the instruction that follows TBB is 2-byte aligned.
// FIXME: Constant island pass should insert an "ALIGN" instruction
// instead.
++NumEntries;
return NumEntries * EntrySize + InstSize;
}
default:
// Otherwise, pseudo-instruction sizes are zero.
return 0;
}
}
}
return 0; // Not reached
}
unsigned
ARMBaseInstrInfo::isLoadFromStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
default: break;
case ARM::LDR:
case ARM::t2LDRs: // FIXME: don't use t2LDRs to access frame.
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isReg() &&
MI->getOperand(3).isImm() &&
MI->getOperand(2).getReg() == 0 &&
MI->getOperand(3).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::t2LDRi12:
case ARM::tRestore:
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isImm() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::VLDRD:
case ARM::VLDRS:
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isImm() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
unsigned
ARMBaseInstrInfo::isStoreToStackSlot(const MachineInstr *MI,
int &FrameIndex) const {
switch (MI->getOpcode()) {
default: break;
case ARM::STR:
case ARM::t2STRs: // FIXME: don't use t2STRs to access frame.
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isReg() &&
MI->getOperand(3).isImm() &&
MI->getOperand(2).getReg() == 0 &&
MI->getOperand(3).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::t2STRi12:
case ARM::tSpill:
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isImm() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
case ARM::VSTRD:
case ARM::VSTRS:
if (MI->getOperand(1).isFI() &&
MI->getOperand(2).isImm() &&
MI->getOperand(2).getImm() == 0) {
FrameIndex = MI->getOperand(1).getIndex();
return MI->getOperand(0).getReg();
}
break;
}
return 0;
}
void ARMBaseInstrInfo::copyPhysReg(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I, DebugLoc DL,
unsigned DestReg, unsigned SrcReg,
bool KillSrc) const {
bool GPRDest = ARM::GPRRegClass.contains(DestReg);
bool GPRSrc = ARM::GPRRegClass.contains(SrcReg);
if (GPRDest && GPRSrc) {
AddDefaultCC(AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::MOVr), DestReg)
.addReg(SrcReg, getKillRegState(KillSrc))));
return;
}
bool SPRDest = ARM::SPRRegClass.contains(DestReg);
bool SPRSrc = ARM::SPRRegClass.contains(SrcReg);
unsigned Opc;
if (SPRDest && SPRSrc)
Opc = ARM::VMOVS;
else if (GPRDest && SPRSrc)
Opc = ARM::VMOVRS;
else if (SPRDest && GPRSrc)
Opc = ARM::VMOVSR;
else if (ARM::DPRRegClass.contains(DestReg, SrcReg))
Opc = ARM::VMOVD;
else if (ARM::QPRRegClass.contains(DestReg, SrcReg))
Opc = ARM::VMOVQ;
else if (ARM::QQPRRegClass.contains(DestReg, SrcReg))
Opc = ARM::VMOVQQ;
else if (ARM::QQQQPRRegClass.contains(DestReg, SrcReg))
Opc = ARM::VMOVQQQQ;
else
llvm_unreachable("Impossible reg-to-reg copy");
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(Opc), DestReg);
MIB.addReg(SrcReg, getKillRegState(KillSrc));
if (Opc != ARM::VMOVQQ && Opc != ARM::VMOVQQQQ)
AddDefaultPred(MIB);
}
static const
MachineInstrBuilder &AddDReg(MachineInstrBuilder &MIB,
unsigned Reg, unsigned SubIdx, unsigned State,
const TargetRegisterInfo *TRI) {
if (!SubIdx)
return MIB.addReg(Reg, State);
if (TargetRegisterInfo::isPhysicalRegister(Reg))
return MIB.addReg(TRI->getSubReg(Reg, SubIdx), State);
return MIB.addReg(Reg, State, SubIdx);
}
void ARMBaseInstrInfo::
storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned SrcReg, bool isKill, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
unsigned Align = MFI.getObjectAlignment(FI);
MachineMemOperand *MMO =
MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
MachineMemOperand::MOStore, 0,
MFI.getObjectSize(FI),
Align);
// tGPR is used sometimes in ARM instructions that need to avoid using
// certain registers. Just treat it as GPR here. Likewise, rGPR.
if (RC == ARM::tGPRRegisterClass || RC == ARM::tcGPRRegisterClass
|| RC == ARM::rGPRRegisterClass)
RC = ARM::GPRRegisterClass;
switch (RC->getID()) {
case ARM::GPRRegClassID:
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::STR))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO));
break;
case ARM::SPRRegClassID:
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTRS))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
break;
case ARM::DPRRegClassID:
case ARM::DPR_VFP2RegClassID:
case ARM::DPR_8RegClassID:
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTRD))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
break;
case ARM::QPRRegClassID:
case ARM::QPR_VFP2RegClassID:
case ARM::QPR_8RegClassID:
// FIXME: Neon instructions should support predicates
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VST1q))
.addFrameIndex(FI).addImm(16)
.addReg(SrcReg, getKillRegState(isKill))
.addMemOperand(MMO));
} else {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMQ))
.addReg(SrcReg, getKillRegState(isKill))
.addFrameIndex(FI)
.addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4))
.addMemOperand(MMO));
}
break;
case ARM::QQPRRegClassID:
case ARM::QQPR_VFP2RegClassID:
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
// FIXME: It's possible to only store part of the QQ register if the
// spilled def has a sub-register index.
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VST1d64Q))
.addFrameIndex(FI).addImm(16);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_3, 0, TRI);
AddDefaultPred(MIB.addMemOperand(MMO));
} else {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMD))
.addFrameIndex(FI)
.addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4)))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
AddDReg(MIB, SrcReg, ARM::dsub_3, 0, TRI);
}
break;
case ARM::QQQQPRRegClassID: {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VSTMD))
.addFrameIndex(FI)
.addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4)))
.addMemOperand(MMO);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_0, getKillRegState(isKill), TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_1, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_2, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_3, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_4, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_5, 0, TRI);
MIB = AddDReg(MIB, SrcReg, ARM::dsub_6, 0, TRI);
AddDReg(MIB, SrcReg, ARM::dsub_7, 0, TRI);
break;
}
default:
llvm_unreachable("Unknown regclass!");
}
}
void ARMBaseInstrInfo::
loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
unsigned DestReg, int FI,
const TargetRegisterClass *RC,
const TargetRegisterInfo *TRI) const {
DebugLoc DL;
if (I != MBB.end()) DL = I->getDebugLoc();
MachineFunction &MF = *MBB.getParent();
MachineFrameInfo &MFI = *MF.getFrameInfo();
unsigned Align = MFI.getObjectAlignment(FI);
MachineMemOperand *MMO =
MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
MachineMemOperand::MOLoad, 0,
MFI.getObjectSize(FI),
Align);
// tGPR is used sometimes in ARM instructions that need to avoid using
// certain registers. Just treat it as GPR here.
if (RC == ARM::tGPRRegisterClass || RC == ARM::tcGPRRegisterClass
|| RC == ARM::rGPRRegisterClass)
RC = ARM::GPRRegisterClass;
switch (RC->getID()) {
case ARM::GPRRegClassID:
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::LDR), DestReg)
.addFrameIndex(FI).addReg(0).addImm(0).addMemOperand(MMO));
break;
case ARM::SPRRegClassID:
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDRS), DestReg)
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
break;
case ARM::DPRRegClassID:
case ARM::DPR_VFP2RegClassID:
case ARM::DPR_8RegClassID:
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDRD), DestReg)
.addFrameIndex(FI).addImm(0).addMemOperand(MMO));
break;
case ARM::QPRRegClassID:
case ARM::QPR_VFP2RegClassID:
case ARM::QPR_8RegClassID:
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLD1q), DestReg)
.addFrameIndex(FI).addImm(16)
.addMemOperand(MMO));
} else {
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMQ), DestReg)
.addFrameIndex(FI)
.addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4))
.addMemOperand(MMO));
}
break;
case ARM::QQPRRegClassID:
case ARM::QQPR_VFP2RegClassID:
if (Align >= 16 && getRegisterInfo().canRealignStack(MF)) {
MachineInstrBuilder MIB = BuildMI(MBB, I, DL, get(ARM::VLD1d64Q));
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::Define, TRI);
AddDefaultPred(MIB.addFrameIndex(FI).addImm(16).addMemOperand(MMO));
} else {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMD))
.addFrameIndex(FI)
.addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4)))
.addMemOperand(MMO);
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::Define, TRI);
AddDReg(MIB, DestReg, ARM::dsub_3, RegState::Define, TRI);
}
break;
case ARM::QQQQPRRegClassID: {
MachineInstrBuilder MIB =
AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::VLDMD))
.addFrameIndex(FI)
.addImm(ARM_AM::getAM5Opc(ARM_AM::ia, 4)))
.addMemOperand(MMO);
MIB = AddDReg(MIB, DestReg, ARM::dsub_0, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_1, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_2, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_3, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_4, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_5, RegState::Define, TRI);
MIB = AddDReg(MIB, DestReg, ARM::dsub_6, RegState::Define, TRI);
AddDReg(MIB, DestReg, ARM::dsub_7, RegState::Define, TRI);
break;
}
default:
llvm_unreachable("Unknown regclass!");
}
}
MachineInstr*
ARMBaseInstrInfo::emitFrameIndexDebugValue(MachineFunction &MF,
int FrameIx, uint64_t Offset,
const MDNode *MDPtr,
DebugLoc DL) const {
MachineInstrBuilder MIB = BuildMI(MF, DL, get(ARM::DBG_VALUE))
.addFrameIndex(FrameIx).addImm(0).addImm(Offset).addMetadata(MDPtr);
return &*MIB;
}
/// Create a copy of a const pool value. Update CPI to the new index and return
/// the label UID.
static unsigned duplicateCPV(MachineFunction &MF, unsigned &CPI) {
MachineConstantPool *MCP = MF.getConstantPool();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPI];
assert(MCPE.isMachineConstantPoolEntry() &&
"Expecting a machine constantpool entry!");
ARMConstantPoolValue *ACPV =
static_cast<ARMConstantPoolValue*>(MCPE.Val.MachineCPVal);
unsigned PCLabelId = AFI->createConstPoolEntryUId();
ARMConstantPoolValue *NewCPV = 0;
if (ACPV->isGlobalValue())
NewCPV = new ARMConstantPoolValue(ACPV->getGV(), PCLabelId,
ARMCP::CPValue, 4);
else if (ACPV->isExtSymbol())
NewCPV = new ARMConstantPoolValue(MF.getFunction()->getContext(),
ACPV->getSymbol(), PCLabelId, 4);
else if (ACPV->isBlockAddress())
NewCPV = new ARMConstantPoolValue(ACPV->getBlockAddress(), PCLabelId,
ARMCP::CPBlockAddress, 4);
else
llvm_unreachable("Unexpected ARM constantpool value type!!");
CPI = MCP->getConstantPoolIndex(NewCPV, MCPE.getAlignment());
return PCLabelId;
}
void ARMBaseInstrInfo::
reMaterialize(MachineBasicBlock &MBB,
MachineBasicBlock::iterator I,
unsigned DestReg, unsigned SubIdx,
const MachineInstr *Orig,
const TargetRegisterInfo &TRI) const {
unsigned Opcode = Orig->getOpcode();
switch (Opcode) {
default: {
MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
MI->substituteRegister(Orig->getOperand(0).getReg(), DestReg, SubIdx, TRI);
MBB.insert(I, MI);
break;
}
case ARM::tLDRpci_pic:
case ARM::t2LDRpci_pic: {
MachineFunction &MF = *MBB.getParent();
unsigned CPI = Orig->getOperand(1).getIndex();
unsigned PCLabelId = duplicateCPV(MF, CPI);
MachineInstrBuilder MIB = BuildMI(MBB, I, Orig->getDebugLoc(), get(Opcode),
DestReg)
.addConstantPoolIndex(CPI).addImm(PCLabelId);
(*MIB).setMemRefs(Orig->memoperands_begin(), Orig->memoperands_end());
break;
}
}
}
MachineInstr *
ARMBaseInstrInfo::duplicate(MachineInstr *Orig, MachineFunction &MF) const {
MachineInstr *MI = TargetInstrInfoImpl::duplicate(Orig, MF);
switch(Orig->getOpcode()) {
case ARM::tLDRpci_pic:
case ARM::t2LDRpci_pic: {
unsigned CPI = Orig->getOperand(1).getIndex();
unsigned PCLabelId = duplicateCPV(MF, CPI);
Orig->getOperand(1).setIndex(CPI);
Orig->getOperand(2).setImm(PCLabelId);
break;
}
}
return MI;
}
bool ARMBaseInstrInfo::produceSameValue(const MachineInstr *MI0,
const MachineInstr *MI1) const {
int Opcode = MI0->getOpcode();
if (Opcode == ARM::t2LDRpci ||
Opcode == ARM::t2LDRpci_pic ||
Opcode == ARM::tLDRpci ||
Opcode == ARM::tLDRpci_pic) {
if (MI1->getOpcode() != Opcode)
return false;
if (MI0->getNumOperands() != MI1->getNumOperands())
return false;
const MachineOperand &MO0 = MI0->getOperand(1);
const MachineOperand &MO1 = MI1->getOperand(1);
if (MO0.getOffset() != MO1.getOffset())
return false;
const MachineFunction *MF = MI0->getParent()->getParent();
const MachineConstantPool *MCP = MF->getConstantPool();
int CPI0 = MO0.getIndex();
int CPI1 = MO1.getIndex();
const MachineConstantPoolEntry &MCPE0 = MCP->getConstants()[CPI0];
const MachineConstantPoolEntry &MCPE1 = MCP->getConstants()[CPI1];
ARMConstantPoolValue *ACPV0 =
static_cast<ARMConstantPoolValue*>(MCPE0.Val.MachineCPVal);
ARMConstantPoolValue *ACPV1 =
static_cast<ARMConstantPoolValue*>(MCPE1.Val.MachineCPVal);
return ACPV0->hasSameValue(ACPV1);
}
return MI0->isIdenticalTo(MI1, MachineInstr::IgnoreVRegDefs);
}
/// areLoadsFromSameBasePtr - This is used by the pre-regalloc scheduler to
/// determine if two loads are loading from the same base address. It should
/// only return true if the base pointers are the same and the only differences
/// between the two addresses is the offset. It also returns the offsets by
/// reference.
bool ARMBaseInstrInfo::areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2,
int64_t &Offset1,
int64_t &Offset2) const {
// Don't worry about Thumb: just ARM and Thumb2.
if (Subtarget.isThumb1Only()) return false;
if (!Load1->isMachineOpcode() || !Load2->isMachineOpcode())
return false;
switch (Load1->getMachineOpcode()) {
default:
return false;
case ARM::LDR:
case ARM::LDRB:
case ARM::LDRD:
case ARM::LDRH:
case ARM::LDRSB:
case ARM::LDRSH:
case ARM::VLDRD:
case ARM::VLDRS:
case ARM::t2LDRi8:
case ARM::t2LDRDi8:
case ARM::t2LDRSHi8:
case ARM::t2LDRi12:
case ARM::t2LDRSHi12:
break;
}
switch (Load2->getMachineOpcode()) {
default:
return false;
case ARM::LDR:
case ARM::LDRB:
case ARM::LDRD:
case ARM::LDRH:
case ARM::LDRSB:
case ARM::LDRSH:
case ARM::VLDRD:
case ARM::VLDRS:
case ARM::t2LDRi8:
case ARM::t2LDRDi8:
case ARM::t2LDRSHi8:
case ARM::t2LDRi12:
case ARM::t2LDRSHi12:
break;
}
// Check if base addresses and chain operands match.
if (Load1->getOperand(0) != Load2->getOperand(0) ||
Load1->getOperand(4) != Load2->getOperand(4))
return false;
// Index should be Reg0.
if (Load1->getOperand(3) != Load2->getOperand(3))
return false;
// Determine the offsets.
if (isa<ConstantSDNode>(Load1->getOperand(1)) &&
isa<ConstantSDNode>(Load2->getOperand(1))) {
Offset1 = cast<ConstantSDNode>(Load1->getOperand(1))->getSExtValue();
Offset2 = cast<ConstantSDNode>(Load2->getOperand(1))->getSExtValue();
return true;
}
return false;
}
/// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
/// determine (in conjuction with areLoadsFromSameBasePtr) if two loads should
/// be scheduled togther. On some targets if two loads are loading from
/// addresses in the same cache line, it's better if they are scheduled
/// together. This function takes two integers that represent the load offsets
/// from the common base address. It returns true if it decides it's desirable
/// to schedule the two loads together. "NumLoads" is the number of loads that
/// have already been scheduled after Load1.
bool ARMBaseInstrInfo::shouldScheduleLoadsNear(SDNode *Load1, SDNode *Load2,
int64_t Offset1, int64_t Offset2,
unsigned NumLoads) const {
// Don't worry about Thumb: just ARM and Thumb2.
if (Subtarget.isThumb1Only()) return false;
assert(Offset2 > Offset1);
if ((Offset2 - Offset1) / 8 > 64)
return false;
if (Load1->getMachineOpcode() != Load2->getMachineOpcode())
return false; // FIXME: overly conservative?
// Four loads in a row should be sufficient.
if (NumLoads >= 3)
return false;
return true;
}
bool ARMBaseInstrInfo::isSchedulingBoundary(const MachineInstr *MI,
const MachineBasicBlock *MBB,
const MachineFunction &MF) const {
// Debug info is never a scheduling boundary. It's necessary to be explicit
// due to the special treatment of IT instructions below, otherwise a
// dbg_value followed by an IT will result in the IT instruction being
// considered a scheduling hazard, which is wrong. It should be the actual
// instruction preceding the dbg_value instruction(s), just like it is
// when debug info is not present.
if (MI->isDebugValue())
return false;
// Terminators and labels can't be scheduled around.
if (MI->getDesc().isTerminator() || MI->isLabel())
return true;
// Treat the start of the IT block as a scheduling boundary, but schedule
// t2IT along with all instructions following it.
// FIXME: This is a big hammer. But the alternative is to add all potential
// true and anti dependencies to IT block instructions as implicit operands
// to the t2IT instruction. The added compile time and complexity does not
// seem worth it.
MachineBasicBlock::const_iterator I = MI;
// Make sure to skip any dbg_value instructions
while (++I != MBB->end() && I->isDebugValue())
;
if (I != MBB->end() && I->getOpcode() == ARM::t2IT)
return true;
// Don't attempt to schedule around any instruction that defines
// a stack-oriented pointer, as it's unlikely to be profitable. This
// saves compile time, because it doesn't require every single
// stack slot reference to depend on the instruction that does the
// modification.
if (MI->definesRegister(ARM::SP))
return true;
return false;
}
bool ARMBaseInstrInfo::
isProfitableToIfCvt(MachineBasicBlock &MBB, unsigned NumInstrs) const {
if (!NumInstrs)
return false;
if (Subtarget.getCPUString() == "generic")
// Generic (and overly aggressive) if-conversion limits for testing.
return NumInstrs <= 10;
else if (Subtarget.hasV7Ops())
return NumInstrs <= 3;
return NumInstrs <= 2;
}
bool ARMBaseInstrInfo::
isProfitableToIfCvt(MachineBasicBlock &TMBB, unsigned NumT,
MachineBasicBlock &FMBB, unsigned NumF) const {
return NumT && NumF && NumT <= 2 && NumF <= 2;
}
/// getInstrPredicate - If instruction is predicated, returns its predicate
/// condition, otherwise returns AL. It also returns the condition code
/// register by reference.
ARMCC::CondCodes
llvm::getInstrPredicate(const MachineInstr *MI, unsigned &PredReg) {
int PIdx = MI->findFirstPredOperandIdx();
if (PIdx == -1) {
PredReg = 0;
return ARMCC::AL;
}
PredReg = MI->getOperand(PIdx+1).getReg();
return (ARMCC::CondCodes)MI->getOperand(PIdx).getImm();
}
int llvm::getMatchingCondBranchOpcode(int Opc) {
if (Opc == ARM::B)
return ARM::Bcc;
else if (Opc == ARM::tB)
return ARM::tBcc;
else if (Opc == ARM::t2B)
return ARM::t2Bcc;
llvm_unreachable("Unknown unconditional branch opcode!");
return 0;
}
void llvm::emitARMRegPlusImmediate(MachineBasicBlock &MBB,
MachineBasicBlock::iterator &MBBI, DebugLoc dl,
unsigned DestReg, unsigned BaseReg, int NumBytes,
ARMCC::CondCodes Pred, unsigned PredReg,
const ARMBaseInstrInfo &TII) {
bool isSub = NumBytes < 0;
if (isSub) NumBytes = -NumBytes;
while (NumBytes) {
unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt);
assert(ThisVal && "Didn't extract field correctly");
// We will handle these bits from offset, clear them.
NumBytes &= ~ThisVal;
assert(ARM_AM::getSOImmVal(ThisVal) != -1 && "Bit extraction didn't work?");
// Build the new ADD / SUB.
unsigned Opc = isSub ? ARM::SUBri : ARM::ADDri;
BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
.addReg(BaseReg, RegState::Kill).addImm(ThisVal)
.addImm((unsigned)Pred).addReg(PredReg).addReg(0);
BaseReg = DestReg;
}
}
bool llvm::rewriteARMFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
unsigned FrameReg, int &Offset,
const ARMBaseInstrInfo &TII) {
unsigned Opcode = MI.getOpcode();
const TargetInstrDesc &Desc = MI.getDesc();
unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
bool isSub = false;
// Memory operands in inline assembly always use AddrMode2.
if (Opcode == ARM::INLINEASM)
AddrMode = ARMII::AddrMode2;
if (Opcode == ARM::ADDri) {
Offset += MI.getOperand(FrameRegIdx+1).getImm();
if (Offset == 0) {
// Turn it into a move.
MI.setDesc(TII.get(ARM::MOVr));
MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
MI.RemoveOperand(FrameRegIdx+1);
Offset = 0;
return true;
} else if (Offset < 0) {
Offset = -Offset;
isSub = true;
MI.setDesc(TII.get(ARM::SUBri));
}
// Common case: small offset, fits into instruction.
if (ARM_AM::getSOImmVal(Offset) != -1) {
// Replace the FrameIndex with sp / fp
MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
Offset = 0;
return true;
}
// Otherwise, pull as much of the immedidate into this ADDri/SUBri
// as possible.
unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt);
// We will handle these bits from offset, clear them.
Offset &= ~ThisImmVal;
// Get the properly encoded SOImmVal field.
assert(ARM_AM::getSOImmVal(ThisImmVal) != -1 &&
"Bit extraction didn't work?");
MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
} else {
unsigned ImmIdx = 0;
int InstrOffs = 0;
unsigned NumBits = 0;
unsigned Scale = 1;
switch (AddrMode) {
case ARMII::AddrMode2: {
ImmIdx = FrameRegIdx+2;
InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm());
if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
InstrOffs *= -1;
NumBits = 12;
break;
}
case ARMII::AddrMode3: {
ImmIdx = FrameRegIdx+2;
InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm());
if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
InstrOffs *= -1;
NumBits = 8;
break;
}
case ARMII::AddrMode4:
case ARMII::AddrMode6:
// Can't fold any offset even if it's zero.
return false;
case ARMII::AddrMode5: {
ImmIdx = FrameRegIdx+1;
InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm());
if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
InstrOffs *= -1;
NumBits = 8;
Scale = 4;
break;
}
default:
llvm_unreachable("Unsupported addressing mode!");
break;
}
Offset += InstrOffs * Scale;
assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
if (Offset < 0) {
Offset = -Offset;
isSub = true;
}
// Attempt to fold address comp. if opcode has offset bits
if (NumBits > 0) {
// Common case: small offset, fits into instruction.
MachineOperand &ImmOp = MI.getOperand(ImmIdx);
int ImmedOffset = Offset / Scale;
unsigned Mask = (1 << NumBits) - 1;
if ((unsigned)Offset <= Mask * Scale) {
// Replace the FrameIndex with sp
MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
if (isSub)
ImmedOffset |= 1 << NumBits;
ImmOp.ChangeToImmediate(ImmedOffset);
Offset = 0;
return true;
}
// Otherwise, it didn't fit. Pull in what we can to simplify the immed.
ImmedOffset = ImmedOffset & Mask;
if (isSub)
ImmedOffset |= 1 << NumBits;
ImmOp.ChangeToImmediate(ImmedOffset);
Offset &= ~(Mask*Scale);
}
}
Offset = (isSub) ? -Offset : Offset;
return Offset == 0;
}
bool ARMBaseInstrInfo::
AnalyzeCompare(const MachineInstr *MI, unsigned &SrcReg, int &CmpValue) const {
switch (MI->getOpcode()) {
default: break;
case ARM::CMPri:
case ARM::CMPzri:
case ARM::t2CMPri:
case ARM::t2CMPzri:
SrcReg = MI->getOperand(0).getReg();
CmpValue = MI->getOperand(1).getImm();
return true;
}
return false;
}
/// ConvertToSetZeroFlag - Convert the instruction to set the "zero" flag so
/// that we can remove a "comparison with zero".
bool ARMBaseInstrInfo::
ConvertToSetZeroFlag(MachineInstr *MI, MachineInstr *CmpInstr) const {
// Conservatively refuse to convert an instruction which isn't in the same BB
// as the comparison.
if (MI->getParent() != CmpInstr->getParent())
return false;
// Check that CPSR isn't set between the comparison instruction and the one we
// want to change.
MachineBasicBlock::const_iterator I = CmpInstr, E = MI;
--I;
for (; I != E; --I) {
const MachineInstr &Instr = *I;
for (unsigned IO = 0, EO = Instr.getNumOperands(); IO != EO; ++IO) {
const MachineOperand &MO = Instr.getOperand(IO);
if (!MO.isReg() || !MO.isDef()) continue;
// This instruction modifies CPSR before the one we want to change. We
// can't do this transformation.
if (MO.getReg() == ARM::CPSR)
return false;
}
}
// Set the "zero" bit in CPSR.
switch (MI->getOpcode()) {
default: break;
case ARM::ADDri:
case ARM::SUBri:
case ARM::t2ADDri:
case ARM::t2SUBri:
MI->RemoveOperand(5);
MachineInstrBuilder(MI)
.addReg(ARM::CPSR, RegState::Define | RegState::Implicit);
CmpInstr->eraseFromParent();
return true;
}
return false;
}
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