darling-JavaScriptCore/b3/B3BreakCriticalEdges.cpp

70 lines
2.5 KiB
C++

/*
* Copyright (C) 2016-2018 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.
*/
#include "config.h"
#include "B3BreakCriticalEdges.h"
#if ENABLE(B3_JIT)
#include "B3BasicBlockInlines.h"
#include "B3BlockInsertionSet.h"
#include "B3ValueInlines.h"
namespace JSC { namespace B3 {
void breakCriticalEdges(Procedure& proc)
{
BlockInsertionSet insertionSet(proc);
for (BasicBlock* block : proc) {
// Non-void terminals that are the moral equivalent of jumps trigger critical edge breaking
// because of fixSSA's demoteValues.
if (block->numSuccessors() <= 1
&& block->last()->type() == Void)
continue;
for (BasicBlock*& successor : block->successorBlocks()) {
if (successor->numPredecessors() <= 1)
continue;
BasicBlock* pad =
insertionSet.insertBefore(successor, successor->frequency());
pad->appendNew<Value>(proc, Jump, successor->at(0)->origin());
pad->setSuccessors(FrequentedBlock(successor));
pad->addPredecessor(block);
successor->replacePredecessor(block, pad);
successor = pad;
}
}
if (insertionSet.execute())
proc.invalidateCFG();
}
} } // namespace JSC::B3
#endif // ENABLE(B3_JIT)