/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
#pragma once

#if ENABLE(DFG_JIT)

namespace JSC { namespace DFG {

class BlockInsertionSet;
class Graph;
struct BasicBlock;

// Inserts dummy basic blocks before any loop headers that don't already have
// a single non-loop predecessor.

bool performLoopPreHeaderCreation(Graph&);

// Creates a new basic block (a pre-header) that jumps to the given block. All
// predecessors of the given block that aren't dominated by it are rerouted to
// the pre-header.
//
// This function is used internally and it's used in a surgical fashion by
// OSREntrypointCreationPhase.
//
// Note that executing this function requires having an intact dominators
// analysis. You should run that analysis before doing damage to the CFG, even
// if said damage is done before you call this.
BasicBlock* createPreHeader(Graph&, BlockInsertionSet&, BasicBlock*);

} } // namespace JSC::DFG

#endif // ENABLE(DFG_JIT)