blob: bdd62167d6715cdb53de319756efd002a5296983 [file] [log] [blame]
/*
* Copyright (C) 2013 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef DFGLoopPreHeaderCreationPhase_h
#define DFGLoopPreHeaderCreationPhase_h
#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)
#endif // DFGLoopPreHeaderCreationPhase_h