C++ DenseMap::lookup方法代码示例

 int getStackDepth(SILBasicBlock *BB) {
   assert(Block2StackDepth.find(BB) != Block2StackDepth.end());
   int Depth = Block2StackDepth.lookup(BB);
   assert(Depth >= 0 && "EndBlock not reachable from StartBlock");
   return Depth;
 }

/// Process an apply instruction which uses a partial_apply
/// as its callee.
/// Returns true on success.
bool PartialApplyCombiner::processSingleApply(FullApplySite AI) {
    Builder.setInsertionPoint(AI.getInstruction());
    Builder.setCurrentDebugScope(AI.getDebugScope());

    // Prepare the args.
    SmallVector<SILValue, 8> Args;
    // First the ApplyInst args.
    for (auto Op : AI.getArguments())
        Args.push_back(Op);

    SILInstruction *InsertionPoint = &*Builder.getInsertionPoint();
    // Next, the partial apply args.

    // Pre-process partial_apply arguments only once, lazily.
    if (isFirstTime) {
        isFirstTime = false;
        if (!allocateTemporaries())
            return false;
    }

    // Now, copy over the partial apply args.
    for (auto Op : PAI->getArguments()) {
        auto Arg = Op;
        // If there is new temporary for this argument, use it instead.
        if (isa<AllocStackInst>(Arg)) {
            if (ArgToTmp.count(Arg)) {
                Op = ArgToTmp.lookup(Arg);
            }
        }
        Args.push_back(Op);
    }

    Builder.setInsertionPoint(InsertionPoint);
    Builder.setCurrentDebugScope(AI.getDebugScope());

    // The thunk that implements the partial apply calls the closure function
    // that expects all arguments to be consumed by the function. However, the
    // captured arguments are not arguments of *this* apply, so they are not
    // pre-incremented. When we combine the partial_apply and this apply into
    // a new apply we need to retain all of the closure non-address type
    // arguments.
    auto ParamInfo = PAI->getSubstCalleeType()->getParameters();
    auto PartialApplyArgs = PAI->getArguments();
    // Set of arguments that need to be released after each invocation.
    SmallVector<SILValue, 8> ToBeReleasedArgs;
    for (unsigned i = 0, e = PartialApplyArgs.size(); i < e; ++i) {
        SILValue Arg = PartialApplyArgs[i];
        if (!Arg->getType().isAddress()) {
            // Retain the argument as the callee may consume it.
            Builder.emitRetainValueOperation(PAI->getLoc(), Arg);
            // For non consumed parameters (e.g. guaranteed), we also need to
            // insert releases after each apply instruction that we create.
            if (!ParamInfo[ParamInfo.size() - PartialApplyArgs.size() + i].
                    isConsumed())
                ToBeReleasedArgs.push_back(Arg);
        }
    }

    auto *F = FRI->getReferencedFunction();
    SILType FnType = F->getLoweredType();
    SILType ResultTy = F->getLoweredFunctionType()->getSILResult();
    ArrayRef<Substitution> Subs = PAI->getSubstitutions();
    if (!Subs.empty()) {
        FnType = FnType.substGenericArgs(PAI->getModule(), Subs);
        ResultTy = FnType.getAs<SILFunctionType>()->getSILResult();
    }

    FullApplySite NAI;
    if (auto *TAI = dyn_cast<TryApplyInst>(AI))
        NAI =
            Builder.createTryApply(AI.getLoc(), FRI, FnType, Subs, Args,
                                   TAI->getNormalBB(), TAI->getErrorBB());
    else
        NAI =
            Builder.createApply(AI.getLoc(), FRI, FnType, ResultTy, Subs, Args,
                                cast<ApplyInst>(AI)->isNonThrowing());

    // We also need to release the partial_apply instruction itself because it
    // is consumed by the apply_instruction.
    if (auto *TAI = dyn_cast<TryApplyInst>(AI)) {
        Builder.setInsertionPoint(TAI->getNormalBB()->begin());
        for (auto Arg : ToBeReleasedArgs) {
            Builder.emitReleaseValueOperation(PAI->getLoc(), Arg);
        }
        Builder.createStrongRelease(AI.getLoc(), PAI, Atomicity::Atomic);
        Builder.setInsertionPoint(TAI->getErrorBB()->begin());
        // Release the non-consumed parameters.
        for (auto Arg : ToBeReleasedArgs) {
            Builder.emitReleaseValueOperation(PAI->getLoc(), Arg);
        }
        Builder.createStrongRelease(AI.getLoc(), PAI, Atomicity::Atomic);
        Builder.setInsertionPoint(AI.getInstruction());
    } else {
        // Release the non-consumed parameters.
        for (auto Arg : ToBeReleasedArgs) {
            Builder.emitReleaseValueOperation(PAI->getLoc(), Arg);
        }
//.........这里部分代码省略.........