C++ Opnd::getInst方法代码示例

/**
 * 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);
//.........这里部分代码省略.........

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);
        }
    }
}