Method decomposeBoolean

src/jrd/optimizer/Optimizer.cpp:1264–1355

//

unsigned Optimizer::decomposeBoolean(BoolExprNode* boolNode, BoolExprNodeStack& stack)
{
	if (const auto binaryNode = nodeAs<BinaryBoolNode>(boolNode))
	{
		if (binaryNode->blrOp == blr_and)
		{
			auto count = decomposeBoolean(binaryNode->arg1, stack);
			count += decomposeBoolean(binaryNode->arg2, stack);
			return count;
		}
		else if (binaryNode->blrOp == blr_or)
		{
			BoolExprNodeStack or_stack;

			if (decomposeBoolean(binaryNode->arg1, or_stack) >= 2)
			{
				binaryNode->arg1 = or_stack.pop();

				while (or_stack.hasData())
				{
					const auto newBoolNode =
						FB_NEW_POOL(getPool()) BinaryBoolNode(getPool(), blr_and);
					newBoolNode->arg1 = or_stack.pop();
					newBoolNode->arg2 = binaryNode->arg1;

					binaryNode->arg1 = newBoolNode;
				}
			}

			or_stack.clear();

			if (decomposeBoolean(binaryNode->arg2, or_stack) >= 2)
			{
				binaryNode->arg2 = or_stack.pop();

				while (or_stack.hasData())
				{
					const auto newBoolNode =
						FB_NEW_POOL(getPool()) BinaryBoolNode(getPool(), blr_and);
					newBoolNode->arg1 = or_stack.pop();
					newBoolNode->arg2 = binaryNode->arg2;

					binaryNode->arg2 = newBoolNode;
				}
			}
		}
	}
	else if (const auto cmpNode = nodeAs<ComparativeBoolNode>(boolNode))
	{
		// turn a between into (a greater than or equal) AND (a less than  or equal)

		if (cmpNode->blrOp == blr_between)
		{
			auto newCmpNode = FB_NEW_POOL(getPool()) ComparativeBoolNode(getPool(), blr_geq);
			newCmpNode->arg1 = cmpNode->arg1;
			newCmpNode->arg2 = cmpNode->arg2;

			stack.push(newCmpNode);