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C++ Ptr::optimizationPasses方法代码示例

本文整理汇总了C++中expression::Ptr::optimizationPasses方法的典型用法代码示例。如果您正苦于以下问题:C++ Ptr::optimizationPasses方法的具体用法?C++ Ptr::optimizationPasses怎么用?C++ Ptr::optimizationPasses使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在expression::Ptr的用法示例。


在下文中一共展示了Ptr::optimizationPasses方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C++代码示例。

示例1: invokeOptimizers

Expression::Ptr Expression::invokeOptimizers(const Expression::Ptr &expr,
                                             const StaticContext::Ptr &context)
{
    Q_ASSERT(expr);

    const OptimizationPass::List opts(expr->optimizationPasses());

    if(opts.isEmpty()) /* Early exit. */
    {
        return expr;
    }

    const OptimizationPass::List::const_iterator passEnd(opts.constEnd());
    const OptimizationPass::List::const_iterator end(opts.constEnd());
    OptimizationPass::List::const_iterator passIt(opts.constBegin());

    for(; passIt != passEnd; ++passIt) /* Invoke each optimization pass. */
    {
        const OptimizationPass::Ptr pass(*passIt); /* Alias, for readability. */
        OptimizationPass::ExpressionMarker sourceMarker(pass->sourceExpression);

        if(pass->startIdentifier && !pass->startIdentifier->matches(expr))
        {
            /* This pass specified a start identifier and it did
             * not match -- let's try the next OptimizationPass. */
            continue;
        }

        const ExpressionIdentifier::List::const_iterator idEnd(pass->operandIdentifiers.constEnd());
        ExpressionIdentifier::List::const_iterator idIt(pass->operandIdentifiers.constBegin());
        const Expression::List ops(expr->operands());
        const Expression::List::const_iterator opEnd(ops.constEnd());
        Expression::List::const_iterator opIt(ops.constBegin());

        switch(pass->operandsMatchMethod)
        {
            case OptimizationPass::Sequential:
            {
                for(; opIt != opEnd; ++opIt)
                {
                    const Expression::Ptr operand(*opIt); /* Alias, for readability. */
                    const ExpressionIdentifier::Ptr opIdentifier(*idIt); /* Alias, for readability. */
                    if(opIdentifier && !opIdentifier->matches(operand))
                    {
                        break;
                    }

                    ++idIt;
                }

                if(opIt == opEnd)
                    break; /* All operands matched, so this pass matched. */
                else
                {
                    /* The loop above did not finish which means all operands did not match.
                       Therefore, this OptimizationPass did not match -- let's try the next one. */
                    continue;
                }
            }
            case OptimizationPass::AnyOrder:
            {
                Q_ASSERT_X(ops.count() == 2, Q_FUNC_INFO,
                           "AnyOrder is currently only supported for Expressions with two operands.");
                if(pass->operandIdentifiers.first()->matches(ops.first()) &&
                   pass->operandIdentifiers.last()->matches(ops.last()))
                {
                    break;
                }
                else if(pass->operandIdentifiers.first()->matches(ops.last()) &&
                        pass->operandIdentifiers.last()->matches(ops.first()))
                {
                    sourceMarker.first() = 1;
                    sourceMarker[1] = 0;
                    break; /* This pass matched. */
                }
                else
                    continue; /* This pass didn't match, let's loop through the next pass. */
            }
        }

        /* Figure out the source Expression, if any. */
        Expression::List operands;
        Expression::Ptr sourceExpr;

        if(!sourceMarker.isEmpty())
        {
            const OptimizationPass::ExpressionMarker::const_iterator mEnd(sourceMarker.constEnd());
            OptimizationPass::ExpressionMarker::const_iterator mIt(sourceMarker.constBegin());
            sourceExpr = expr;

            for(; mIt != mEnd; ++mIt)
            {
                Q_ASSERT(*mIt >= 0);
                sourceExpr = sourceExpr->operands().at(*mIt);
            }

            operands.append(sourceExpr);
        }

        if(operands.isEmpty())
//.........这里部分代码省略.........
开发者ID:maxxant,项目名称:qt,代码行数:101,代码来源:qexpression.cpp


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