/**
* Checks if Op_TauStInd (stind) instruction has a side effect.
* @param inst - checked instruction
* @return <code>true</code> if an instruction has side effect;
* <code>false<code> if an instruction has no side effect.
*/
bool
LazyExceptionOpt::fieldUsageHasSideEffect(Inst* inst) {
Opnd* insOp = inst->getSrc(0);
Inst* instDef = insOp->getInst();
if (instDef->getOpcode() == Op_DefArg) {
#ifdef _DEBUG
if (Log::isEnabled()) {
Log::out() << " fieldUsageHasSideEffect: ";
inst->print(Log::out());
Log::out() << std::endl;
Log::out() << " fieldUsageHasSideEffect: ";
instDef->print(Log::out());
Log::out() << std::endl;
Log::out() << " fieldUsageHasSideEffect: ";
Log::out() << (int)(instDef->getDefArgModifier()) << " " <<
(instDef->getDefArgModifier()==DefArgNoModifier) << " " <<
(instDef->getDefArgModifier()==NonNullThisArg) << " " <<
(instDef->getDefArgModifier()==DefArgBothModifiers) << std::endl;
}
#endif
if (instDef->getDefArgModifier()==NonNullThisArg && isExceptionInit)
return false;
}
return true;
}
static void doUnroll(MemoryManager& mm, IRManager& irm, const LoopUnrollInfo* info, const UnrollFlags& flags) {
//unroll algorithm does the following
//before:
// loopOrig {
// bodyA
// check(idxOpnd,limitOpnd)
// bodyB
// }
//after:
// unrolledIncOpnd = unrollCount * idx->increment
// unrolledLimitOpnd = limitOpnd-unrolledIncOpnd;
// bodyA
// loopUnrolled {
// check(idxOpnd,unrolledLimitOpnd)
// bodyB
// bodyA
// bodyB
// ...
// bodyA
// }
// loopEpilogue {
// check(idxOpnd,limitOpnd)
// bodyB
// bodyA
// }
//
//where:
// bodyA - all nodes of the same loop accessible from checkNode via incoming edges
// bodyB - all nodes except bodyA and checkNode
ControlFlowGraph& cfg = irm.getFlowGraph();
LoopTree* lt = cfg.getLoopTree();
InstFactory& instFactory = irm.getInstFactory();
OpndManager& opndManager = irm.getOpndManager();
Type* opType = info->getLimitOpnd()->getType();
// printf("UNROLL\n");
//STEP 0: cache all data needed
assert(info->unrollCount >= 1);
Node* origHeader = info->header;
assert(origHeader->getInDegree() == 2); //loop is normalized
OptPass::computeLoops(irm);//recompute loop info if needed
LoopNode* loopNode = lt->getLoopNode(origHeader, false);
Edge* entryEdge = origHeader->getInEdges().front();
if (lt->isBackEdge(entryEdge)) {
entryEdge = origHeader->getInEdges().back();
}
Node* origCheckNode = info->branchInst->getNode();
Edge* origLoopExitEdge = info->branchTargetIsExit ? origCheckNode->getTrueEdge() : origCheckNode->getFalseEdge();
U_32 maxNodeId = cfg.getMaxNodeId()+1; //+1 for a split check node
StlBitVector nodesInLoop(mm, maxNodeId);
{
const Nodes& loopNodes = loopNode->getNodesInLoop();
for (Nodes::const_iterator it = loopNodes.begin(), end = loopNodes.end(); it!=end; ++it) {
Node* node = *it;
nodesInLoop.setBit(node->getId());
}
}
//STEP 1: calculate bodyA nodes
BitSet aFlags(mm, maxNodeId);
calculateReachableNodesInLoop(loopNode, origHeader, origCheckNode, aFlags);
StlBitVector bodyANodes(mm, maxNodeId);
for (U_32 i=0;i<maxNodeId;i++) bodyANodes.setBit(i, aFlags.getBit(i));
//STEP 2: make checkNode a separate node, prepare loop region
bodyANodes.setBit(origCheckNode->getId(), true);
Node* checkNode = cfg.splitNodeAtInstruction(info->branchInst->prev(), true, false, instFactory.makeLabel());
nodesInLoop.setBit(checkNode->getId(), true);
Node* preCheckNode = origCheckNode;
bodyANodes.setBit(preCheckNode->getId(), true);
//STEP 3: rotate original loop
// before: {bodyA1, check , bodyB}
// after: bodyA2 {check, bodyB, bodyA1}
Edge* bodyA2ToCheckEdge = NULL;
Opnd* limitOpndInBodyA2 = NULL;
{
//WARN: info->limitOpnd and info->indexOpnd can be replaced after code duplication if promoted to vars
Opnd* limitOpndBefore = info->getLimitOpnd();
assert(preCheckNode->getOutDegree()==1 && preCheckNode->getUnconditionalEdgeTarget() == checkNode);
DefUseBuilder defUses(mm);
defUses.initialize(cfg);
OpndRenameTable opndRenameTable(mm, maxNodeId); //todo: maxNodeId is overkill estimate here
NodeRenameTable nodeRenameTable(mm, maxNodeId);
Node* bodyA2 = FlowGraph::duplicateRegion(irm, origHeader, bodyANodes, defUses, nodeRenameTable, opndRenameTable);
cfg.replaceEdgeTarget(entryEdge, bodyA2, true);
// while duplicating a region new nodes could be created and 'nodesInRegion' bitvector param is updated.
// BodyA is part of the loop -> if new nodes were created in the loop we must track them.
nodesInLoop.resize(bodyANodes.size());
for (U_32 i=0;i<bodyANodes.size();i++) nodesInLoop.setBit(i, bodyANodes.getBit(i) || nodesInLoop.getBit(i));
Node* bodyA2PreCheckNode = nodeRenameTable.getMapping(preCheckNode);
assert(bodyA2PreCheckNode->getOutDegree()==1 && bodyA2PreCheckNode->getUnconditionalEdgeTarget() == checkNode);
bodyA2ToCheckEdge = bodyA2PreCheckNode->getUnconditionalEdge();
limitOpndInBodyA2 = limitOpndBefore;
if (nodeRenameTable.getMapping(limitOpndBefore->getInst()->getNode())!=NULL) {
limitOpndInBodyA2 = opndRenameTable.getMapping(limitOpndBefore);
}
assert(limitOpndInBodyA2!=NULL);
}
//STEP 4: prepare epilogue loop: {check, bodyB, bodyA}
Node* epilogueLoopHead = NULL;
{
DefUseBuilder defUses(mm);
defUses.initialize(cfg);
OpndRenameTable opndRenameTable(mm, maxNodeId); //todo: maxNodeId is overkill estimate here
NodeRenameTable nodeRenameTable(mm, maxNodeId);
epilogueLoopHead = FlowGraph::duplicateRegion(irm, checkNode, nodesInLoop, defUses, nodeRenameTable, opndRenameTable);
cfg.replaceEdgeTarget(origLoopExitEdge, epilogueLoopHead, true);
}
//STEP 5: prepare unrolledLimitOpnd and replace it in original loop's check
{
Node* unrolledPreheader = cfg.spliceBlockOnEdge(bodyA2ToCheckEdge, instFactory.makeLabel());
Opnd* unrolledIncOpnd = opndManager.createSsaTmpOpnd(opType);
unrolledPreheader->appendInst(instFactory.makeLdConst(unrolledIncOpnd, info->increment * info->unrollCount));
Opnd* unrolledLimitOpnd = opndManager.createSsaTmpOpnd(opType);
Modifier mod = Modifier(SignedOp)|Modifier(Strict_No)|Modifier(Overflow_None)|Modifier(Exception_Never);
unrolledPreheader->appendInst(instFactory.makeSub(mod, unrolledLimitOpnd, limitOpndInBodyA2, unrolledIncOpnd));
info->branchInst->setSrc(info->branchLimitOpndPos, unrolledLimitOpnd);
}
DefUseBuilder defUses(mm);
defUses.initialize(cfg);
//STEP 6: unroll original loop and remove all checks in duplicated bodies
{
Edge* backedge = preCheckNode->getUnconditionalEdge();
for (int i=1;i<info->unrollCount;i++) {
OpndRenameTable opndRenameTable(mm, maxNodeId);
NodeRenameTable nodeRenameTable(mm, maxNodeId);
Node* unrolledRegionHeader = FlowGraph::duplicateRegion(irm, checkNode, nodesInLoop, defUses, nodeRenameTable, opndRenameTable);
cfg.replaceEdgeTarget(backedge, unrolledRegionHeader, true);
Node* newTail = nodeRenameTable.getMapping(preCheckNode);
assert(newTail->getOutDegree()==1 );
backedge = newTail->getUnconditionalEdge();
cfg.replaceEdgeTarget(backedge, checkNode, true);
//remove check from duplicated code
Node* duplicateCheckNode = nodeRenameTable.getMapping(checkNode);
assert(duplicateCheckNode->getOutDegree()==2);
Edge* exitEdge = info->branchTargetIsExit ? duplicateCheckNode->getTrueEdge() : duplicateCheckNode->getFalseEdge();
duplicateCheckNode->getLastInst()->unlink();
cfg.removeEdge(exitEdge);
}
}
//STEP 7: make old loop colder
if (cfg.hasEdgeProfile()) {
Edge* epilogueExit = info->branchTargetIsExit ? epilogueLoopHead->getTrueEdge() : epilogueLoopHead->getFalseEdge();
epilogueExit->setEdgeProb(epilogueExit->getEdgeProb() * 5);
}
}
void SSABuilder::clearPhiSrcs2(Node *node,
const StlVectorSet<VarOpnd *> *whatVars,
StlVector<VarOpnd *> *changedVars,
const StlVectorSet<Opnd *> *removedVars,
StlVector<Node *> &scratchNodeList)
{
bool needPreds = true;
StlVector<Node *> &preds = scratchNodeList;
Inst* inst = (Inst*)node->getSecondInst();
for (;inst!=NULL && inst->isPhi(); inst = inst->getNextInst()) {
Opnd *dstOp =inst->getDst();
VarOpnd *varOpnd = 0;
if (whatVars) {
varOpnd = dstOp->asVarOpnd();
if (!varOpnd) {
SsaVarOpnd *ssaOpnd = dstOp->asSsaVarOpnd();
assert(ssaOpnd);
varOpnd = ssaOpnd->getVar();
}
if (!whatVars->has(varOpnd))
continue;
}
bool changed=false;
U_32 numSrcs = inst->getNumSrcOperands();
for (U_32 i=0; i<numSrcs; ++i) {
Opnd *thisOpnd = inst->getSrc(i);
if (!(removedVars && removedVars->has(thisOpnd))) {
// need to test whether need to remove
if (needPreds) {
needPreds = false;
const Edges& edges2 = node->getInEdges();
preds.clear();
preds.reserve(edges2.size());
Edges::const_iterator eiter2;
for(eiter2 = edges2.begin(); eiter2 != edges2.end(); ++eiter2){
preds.push_back((*eiter2)->getSourceNode());
}
}
DominatorTree &domTree = frontier.getDominator();
Inst *thisOpndInst = thisOpnd->getInst();
Node *thisOpndInstNode = thisOpndInst->getNode();
if (thisOpndInstNode) {
// the operand's source instruction was not already dead.
StlVector<Node *>::const_iterator
predIter = preds.begin(),
predEnd = preds.end();
bool foundDom = false;
for ( ; predIter != predEnd; ++predIter) {
Node *predNode = *predIter;
if (domTree.dominates(thisOpndInstNode, predNode)) {
// we found it, leave this operand alone.
foundDom = true;
break;
}
}
if (foundDom) continue; // leave operand alone.
}
}
// remove this operand;
if (i < numSrcs-1) {
inst->setSrc(i, inst->getSrc(numSrcs-1));
--i; // re-examine this operand, which is now the last
}
--numSrcs; // we deleted one operand
PhiInst *phiInst = inst->asPhiInst();
assert(phiInst);
phiInst->setNumSrcs(numSrcs);
changed = true;
}
if (changed) {
// note the changed var;
if (!varOpnd) {
varOpnd = dstOp->asVarOpnd();
if (!varOpnd) {
SsaVarOpnd *ssaOpnd = dstOp->asSsaVarOpnd();
assert(ssaOpnd);
varOpnd = ssaOpnd->getVar();
}
}
changedVars->push_back(varOpnd);
}
}
}