//_________________________________________________________________________________________________
void DCE::runImpl()
{
bool early = false;
getArg("early", early);
if (early && !irManager->getCGFlags()->earlyDCEOn) {
return;
}
irManager->updateLivenessInfo();
irManager->calculateOpndStatistics();
BitSet ls(irManager->getMemoryManager(), irManager->getOpndCount());
const Nodes& nodes = irManager->getFlowGraph()->getNodesPostOrder();
#ifdef ORDER
MemoryManager mm("dce_parents");
U_32 opndCount = irManager->getOpndCount();
bool * isParentOpnd = new(mm) bool [opndCount];
memset(isParentOpnd, 0, sizeof(bool) * opndCount);
for (Nodes::const_iterator it = nodes.begin(),end = nodes.end(); it!=end; ++it) {
Node* node = *it;
for (Inst * inst=(Inst*)node->getLastInst(); inst!=NULL; inst=inst->getPrevInst()) {
Opnd* load_obj = inst->getParentObjectLoad();
if (load_obj)
{
isParentOpnd[load_obj->getId()] = true;
}
Opnd* store_obj = inst->getParentObjectStore();
if (store_obj)
{
isParentOpnd[store_obj->getId()] = true;
}
}
}
#endif
for (Nodes::const_iterator it = nodes.begin(),end = nodes.end(); it!=end; ++it) {
Node* node = *it;
if (node->isBlockNode()) {
//Here we'll try to remove redundant branches that could appear after
//branch translations. All such branches are supposed to be conditional.
Inst * inst = (Inst *)node->getLastInst();
if(inst && node->getOutEdges().size() > 1) {
Edges edges = node->getOutEdges();
for (Edges::const_iterator ite1 = ++edges.begin(), end = edges.end(); ite1 != end; ++ite1) {
for (Edges::const_iterator ite2 = edges.begin(); ite1 != ite2; ++ite2) {
Edge *edge1 = *ite1;
Edge *edge2 = *ite2;
assert(edge1 != edge2);
//If this condition is satisfied then there are at least two branches with
//the same destination
if (edge1->getTargetNode() == edge2->getTargetNode()) {
//Check that edges are conditional and the last instruction is branch,
//the other situations are not permitted at the moment
assert(inst->hasKind(Inst::Kind_BranchInst));
assert(edge1->getKind() == Edge::Kind_True ||
edge1->getKind() == Edge::Kind_False);
assert(edge2->getKind() == Edge::Kind_True ||
edge2->getKind() == Edge::Kind_False);
//Remove last instruction if it is a branch
inst->unlink();
irManager->getFlowGraph()->removeEdge(edge2);
}
}
}
}
irManager->getLiveAtExit(node, ls);
for (Inst * inst=(Inst*)node->getLastInst(), * prevInst=NULL; inst!=NULL; inst=prevInst) {
prevInst=inst->getPrevInst();
// Prevent debug traps or instructions with side effects
// like (MOVS) from being removed.
bool deadInst=!inst->hasSideEffect() && (inst->getMnemonic() != Mnemonic_INT3);
#ifdef ORDER //yzm
for (unsigned int i = 0 ; i < inst->getOpndCount() ; i ++)
{
Opnd* opnd = inst->getOpnd(i);
if (isParentOpnd[opnd->getId()])
deadInst = false;
}
#endif
if (deadInst) {
if (inst->hasKind(Inst::Kind_CopyPseudoInst)) {
Opnd * opnd=inst->getOpnd(1);
if (opnd->getType()->isFP() && opnd->getDefiningInst()!=NULL && opnd->getDefiningInst()->getMnemonic()==Mnemonic_CALL) {
deadInst=false;
}
}
if (deadInst) {
Inst::Opnds opnds(inst, Inst::OpndRole_All);
for (Inst::Opnds::iterator ito = opnds.begin(); ito != opnds.end(); ito = opnds.next(ito)) {
Opnd * opnd = inst->getOpnd(ito);
if ((ls.getBit(opnd->getId()) && (inst->getOpndRoles(ito) & Inst::OpndRole_Def)) ||
(((opnd->getMemOpndKind()&(MemOpndKind_Heap|MemOpndKind_StackManualLayout))!=0) && (inst->getMnemonic() != Mnemonic_LEA))) {
deadInst=false;
break;
}
}
}
}
if (deadInst) {
inst->unlink();
} else {
irManager->updateLiveness(inst, ls);
}
}
irManager->getLiveAtEntry(node)->copyFrom(ls);
}
}
irManager->eliminateSameOpndMoves();
irManager->getFlowGraph()->purgeEmptyNodes();
irManager->getFlowGraph()->mergeAdjacentNodes(true, false);
irManager->getFlowGraph()->purgeUnreachableNodes();
irManager->packOpnds();
irManager->invalidateLivenessInfo();
}
PeepHoleOpt::Changed PeepHoleOpt::handleInst_ALU(Inst* inst)
{
// The normal form is 'OPERATION left opnd, right operand'
// except for NOT operation.
const Mnemonic mnemonic = inst->getMnemonic();
if (mnemonic == Mnemonic_NOT) {
// No optimizations this time
return Changed_Nothing;
}
// Only these mnemonics have the majestic name of ALUs.
assert(mnemonic == Mnemonic_ADD || mnemonic == Mnemonic_SUB ||
mnemonic == Mnemonic_ADC || mnemonic == Mnemonic_SBB ||
mnemonic == Mnemonic_OR || mnemonic == Mnemonic_XOR ||
mnemonic == Mnemonic_AND ||
mnemonic == Mnemonic_CMP || mnemonic == Mnemonic_TEST);
if (mnemonic == Mnemonic_AND)
{
Inst::Opnds defs(inst, Inst::OpndRole_Explicit|Inst::OpndRole_Def);
Opnd* dst = inst->getOpnd(defs.begin());
Inst::Opnds uses(inst, Inst::OpndRole_Explicit|Inst::OpndRole_Use);
Opnd* src1= inst->getOpnd(uses.begin());
Opnd* src2= inst->getOpnd(uses.next(uses.begin()));
Opnd *newopnd2;
// test can work only with operands having equal sizes
if (isImm(src2) && src2->getSize() != src1->getSize())
newopnd2 = irManager->newImmOpnd(src1->getType(), src2->getImmValue());
else
newopnd2 = src2;
if (!isMem(dst) && !isMem(src1) && !isMem(src2))
{
BitSet ls(irManager->getMemoryManager(), irManager->getOpndCount());
irManager->updateLivenessInfo();
irManager->getLiveAtExit(inst->getNode(), ls);
for (Inst* i = (Inst*)inst->getNode()->getLastInst(); i!=inst; i = i->getPrevInst()) {
irManager->updateLiveness(i, ls);
}
bool dstNotUsed = !ls.getBit(dst->getId());
if (dstNotUsed)
{
// what: AND opnd1, opnd2 => TEST opnd1, opnd2
// nb: applicable if opnd1 will not be used further
if (inst->getForm() == Inst::Form_Extended)
irManager->newInstEx(Mnemonic_TEST, 0, src1, newopnd2)->insertAfter(inst);
else
irManager->newInst(Mnemonic_TEST, src1, newopnd2)->insertAfter(inst);
inst->unlink();
return Changed_Inst;
}
}
} else if (mnemonic == Mnemonic_ADD) {
/* Change "dst=src+0" to "MOV dst, src" if there is another ADD inst followed in the same BB. */
Inst::Opnds defs(inst, Inst::OpndRole_Explicit|Inst::OpndRole_Def);
Opnd* dst = inst->getOpnd(defs.begin());
Inst::Opnds uses(inst, Inst::OpndRole_Explicit|Inst::OpndRole_Use);
Opnd* src1= inst->getOpnd(uses.begin());
Opnd* src2= inst->getOpnd(uses.next(uses.begin()));
bool src1IsZero = false;
bool src2IsZero = false;
if (src1->isPlacedIn(OpndKind_Imm) && (src1->getImmValue() == 0))
src1IsZero = true;
if (src2->isPlacedIn(OpndKind_Imm) && (src2->getImmValue() == 0))
src2IsZero = true;
bool anotherADD = false;
Inst *iter = inst->getNextInst();
while (iter != NULL) {
if (iter->getMnemonic() == Mnemonic_ADC)
break;
if (iter->getMnemonic() == Mnemonic_ADD) {
anotherADD = true;
break;
}
iter = iter->getNextInst();;
}
if (anotherADD) {
if (src1IsZero) {
irManager->newCopyPseudoInst(Mnemonic_MOV, dst, src2)->insertAfter(inst);
inst->unlink();
return Changed_Inst;
} else if (src2IsZero) {
irManager->newCopyPseudoInst(Mnemonic_MOV, dst, src1)->insertAfter(inst);
inst->unlink();
return Changed_Inst;
}
}
}
return Changed_Nothing;
}
//___________________________________________________________________________________________________
void EarlyPropagation::runImpl()
{
irManager->updateLoopInfo();
U_32 opndCount=irManager->getOpndCount();
MemoryManager mm("early_prop");
OpndInfo * opndInfos = new(mm) OpndInfo[opndCount];
Node * currentLoopHeader = NULL;
bool anyInstHandled=false;
LoopTree* lt = irManager->getFlowGraph()->getLoopTree();
const Nodes& postOrdered = irManager->getFlowGraph()->getNodesPostOrder();
for (Nodes::const_reverse_iterator it = postOrdered.rbegin(), end = postOrdered.rend(); it!=end; ++it) {
Node * node=*it;
if (!node->isBlockNode()) {
continue;
}
Node * loopHeader = lt->getLoopHeader(node, false);
if (currentLoopHeader != loopHeader){
currentLoopHeader = loopHeader;
for (U_32 i = 0; i < opndCount; ++i)
if (opndInfos[i].sourceOpndId != EmptyUint32)
opndInfos[i].defCount++;
}
for (Inst * inst = (Inst*)node->getFirstInst(); inst != NULL; inst=inst->getNextInst()){
bool assignedOpndPropagated = false;
Inst::Opnds opnds(inst, Inst::OpndRole_All);
for (Inst::Opnds::iterator it = opnds.begin(); it != opnds.end(); it = opnds.next(it)){
Opnd * opnd=inst->getOpnd(it);
U_32 roles=inst->getOpndRoles(it);
U_32 opndId = opnd->getId();
OpndInfo& opndInfo = opndInfos[opndId];
U_32 mask = 0;
if (roles & Inst::OpndRole_Def){
++opndInfo.defCount;
}else if (roles & Inst::OpndRole_Use){
if (opndInfo.sourceOpndId != EmptyUint32){
if (opndInfo.sourceOpndDefCountAtCopy < opndInfos[opndInfo.sourceOpndId].defCount)
opndInfo.sourceOpndId = EmptyUint32;
else{
Opnd * srcOpnd = irManager->getOpnd(opndInfo.sourceOpndId);
Constraint co = srcOpnd->getConstraint(Opnd::ConstraintKind_Location);
if (co.getKind() == OpndKind_Mem){
mask = (1<<it)-1;
if ((roles & Inst::OpndRole_Explicit) == 0 ||
inst->hasKind(Inst::Kind_PseudoInst) || irManager->isGCSafePoint(inst) ||
opndInfo.sourceInst != inst->getPrevInst() || assignedOpndPropagated ||
(inst->getConstraint(it, mask, co.getSize())&co).isNull()
)
opndInfo.sourceOpndId = EmptyUint32;
assignedOpndPropagated = true;
}
}
}
}
if (opndInfo.defCount > 1){
opndInfo.sourceOpndId = EmptyUint32;
}
}
/*
Here is the previous version to test whether the inst is copy or not.
bool isCopy = inst->getMnemonic() == Mnemonic_MOV ||(
(inst->getMnemonic() == Mnemonic_ADD || inst->getMnemonic() == Mnemonic_SUB) &&
inst->getOpnd(3)->isPlacedIn(OpndKind_Imm) && inst->getOpnd(3)->getImmValue()==0
&& inst->getOpnd(3)->getRuntimeInfo()==NULL
);
It considered special case of 'dst = src +/- 0' as copy.
In fact there are more similar cases like 'IMUL src, 1 ; shift src, 0' etc.
Such checks are obsolete now, Should as peephole takes care about such copies.
Anyway, the code above had a bug: 'inst->getOpnd(3)' crashes in instructions
in native form (like ADD def_use, use).
*/
const bool isCopy = inst->getMnemonic() == Mnemonic_MOV;
if (isCopy){ // CopyPseudoInst or mov
Opnd * defOpnd = inst->getOpnd(0);
Opnd * srcOpnd = inst->getOpnd(1);
U_32 defOpndId = defOpnd->getId();
OpndInfo * opndInfo = opndInfos + defOpndId;
bool instHandled=false;
bool typeConvOk = isTypeConversionAllowed(srcOpnd, defOpnd);
if (typeConvOk && opndInfo->defCount == 1 && ! srcOpnd->isPlacedIn(OpndKind_Reg)){
if (!defOpnd->hasAssignedPhysicalLocation()){
opndInfo->sourceInst = inst;
opndInfo->sourceOpndId = srcOpnd->getId();
instHandled=true;
}
}
if (instHandled){
if (opndInfos[opndInfo->sourceOpndId].sourceOpndId != EmptyUint32)
opndInfo->sourceOpndId = opndInfos[opndInfo->sourceOpndId].sourceOpndId;
opndInfo->sourceOpndDefCountAtCopy = opndInfos[opndInfo->sourceOpndId].defCount;
anyInstHandled=true;
}
}
}
}
if (anyInstHandled){
Opnd ** replacements = new(mm) Opnd* [opndCount];
memset(replacements, 0, sizeof(Opnd*) * opndCount);
bool hasReplacements = false;
for (U_32 i = 0; i < opndCount; ++i){
if (opndInfos[i].sourceOpndId != EmptyUint32){
Inst * inst = opndInfos[i].sourceInst;
if (inst !=NULL){
inst->unlink();
}
if (opndInfos[i].sourceOpndId != i){
Opnd* origOpnd= irManager->getOpnd(i);
Opnd* replacementOpnd = irManager->getOpnd(opndInfos[i].sourceOpndId);
assert(isTypeConversionAllowed(replacementOpnd, origOpnd));
if (origOpnd->getType()->isUnmanagedPtr() && replacementOpnd->getType()->isInteger()) {
replacementOpnd->setType(origOpnd->getType());
}/* else if (origOpnd->getType()->isObject() && replacementOpnd->getType()->isUnmanagedPtr()) {
replacementOpnd->setType(origOpnd->getType());
}*/
replacements[i] = replacementOpnd;
hasReplacements = true;
}
}
}
if (hasReplacements){
const Nodes& postOrdered = irManager->getFlowGraph()->getNodesPostOrder();
for (Nodes::const_reverse_iterator it = postOrdered.rbegin(), end = postOrdered.rend(); it!=end; ++it) {
Node * node=*it;
if (!node->isBlockNode()) {
continue;
}
for (Inst * inst = (Inst*)node->getFirstInst(); inst != NULL; inst=inst->getNextInst()){
inst->replaceOpnds(replacements);
}
}
}
}
}
/**
* Executes lazy exception optimization pass.
*/
void
LazyExceptionOpt::doLazyExceptionOpt() {
MethodDesc &md = irManager.getMethodDesc();
BitSet excOpnds(leMemManager,irManager.getOpndManager().getNumSsaOpnds());
StlDeque<Inst*> candidateSet(leMemManager);
optCandidates = new (leMemManager) OptCandidates(leMemManager);
Method_Side_Effects m_sideEff = md.getSideEffect();
const Nodes& nodes = irManager.getFlowGraph().getNodes();
Nodes::const_iterator niter;
#ifdef _DEBUG
mtdDesc=&md;
#endif
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << std::endl;
for (int i=0; i<level; i++) Log::out() << " ";
Log::out() << "doLE ";
md.printFullName(Log::out());
Log::out() << " SideEff " << (int)m_sideEff << std::endl;
}
#endif
level++;
U_32 opndId = 0;
isArgCheckNull = false;
isExceptionInit = md.isInstanceInitializer() &&
md.getParentType()->isLikelyExceptionType();
// core api exception init
if (m_sideEff == MSE_Unknown && isExceptionInit
&& strncmp(md.getParentType()->getName(),"java/lang/",10) == 0) {
m_sideEff = MSE_False;
md.setSideEffect(m_sideEff);
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << " core api exc ";
md.printFullName(Log::out());
Log::out() << " SideEff " << (int)m_sideEff << std::endl;
}
#endif
}
for(niter = nodes.begin(); niter != nodes.end(); ++niter) {
Node* node = *niter;
Inst *headInst = (Inst*)node->getFirstInst();
for (Inst* inst=headInst->getNextInst(); inst!=NULL; inst=inst->getNextInst()) {
#ifdef _DEBUG
if (inst->getOpcode()==Op_DefArg && isExceptionInit) {
if (Log::isEnabled()) {
Log::out() << " defarg: ";
inst->print(Log::out());
Log::out() << std::endl;
Log::out() << " ";
Log::out() << (int)(inst->getDefArgModifier()) << " " <<
(inst->getDefArgModifier()==DefArgNoModifier) << " " <<
(inst->getDefArgModifier()==NonNullThisArg) << " " <<
(inst->getDefArgModifier()==SpecializedToExactType) << " " <<
(inst->getDefArgModifier()==DefArgBothModifiers) << std::endl;
}
}
#endif
if (inst->getOpcode()==Op_Throw) {
if (inst->getSrc(0)->getInst()->getOpcode()==Op_NewObj) {
excOpnds.setBit(opndId=inst->getSrc(0)->getId(),true);
if (!addOptCandidates(opndId,inst))
excOpnds.setBit(opndId,false); // different exc. edges
#ifdef _DEBUG
if (excOpnds.getBit(opndId)==1) {
if (Log::isEnabled()) {
Log::out() << " add opnd: ";
inst->print(Log::out());
Log::out() << std::endl;
Log::out() << " add obj: ";
inst->getSrc(0)->getInst()->print(Log::out());
Log::out() << std::endl;
}
}
#endif
}
}
if (m_sideEff == MSE_Unknown)
if (instHasSideEffect(inst)) {
m_sideEff = MSE_True;
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << "~~~~~~inst sideEff ";
inst->print(Log::out());
Log::out() << std::endl;
}
#endif
}
}
}
if (md.getSideEffect() == MSE_Unknown) {
if (m_sideEff == MSE_Unknown) {
if (isExceptionInit && isArgCheckNull) {
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << "~~~~~~init sideEff reset: " << m_sideEff << " 3 ";
md.printFullName(Log::out());
Log::out() << std::endl;
}
#endif
m_sideEff = MSE_True_Null_Param;
} else
m_sideEff = MSE_False;
}
md.setSideEffect(m_sideEff);
}
for(niter = nodes.begin(); niter != nodes.end(); ++niter) {
Node* node = *niter;
Inst *headInst = (Inst*)node->getFirstInst();
Opnd* opnd;
for (Inst* inst=headInst->getNextInst(); inst!=NULL; inst=inst->getNextInst()) {
U_32 nsrc = inst->getNumSrcOperands();
for (U_32 i=0; i<nsrc; i++) {
if (!(opnd=inst->getSrc(i))->isSsaOpnd()) // check ssa operands
continue;
if (excOpnds.getBit(opndId=opnd->getId())==0)
continue;
if (inst->getOpcode()==Op_DirectCall) {
MethodDesc* md = inst->asMethodInst()->getMethodDesc();
if (md->isInstanceInitializer() &&
md->getParentType()->isLikelyExceptionType()) {
if (!addOptCandidates(opndId,inst)) {
excOpnds.setBit(opndId,false);
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << " - rem opnd " << opnd->getId() << " ";
inst->print(Log::out());
Log::out() << std::endl;
}
#endif
}
} else {
excOpnds.setBit(opndId,false);
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << " -- rem opnd " << opnd->getId() << " ";
inst->print(Log::out());
Log::out() << std::endl;
}
#endif
}
} else {
if (inst->getOpcode()!=Op_Throw) {
excOpnds.setBit(opndId,false);
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << " rem opnd " << opnd->getId() << " ";
inst->print(Log::out());
Log::out() << std::endl;
}
#endif
}
}
}
}
}
if (!excOpnds.isEmpty()) {
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << "------LE: ";
md.printFullName(Log::out());
Log::out() << std::endl;
}
#endif
fixOptCandidates(&excOpnds);
}
level--;
#ifdef _DEBUG
if (Log::isEnabled()) {
for (int i=0; i<level; i++) Log::out() << " ";
Log::out() << "done ";
md.printFullName(Log::out());
Log::out() << " SideEff " << (int)m_sideEff << std::endl;
}
#endif
};
