summaryrefslogtreecommitdiff
path: root/Source/JavaScriptCore/dfg/DFGStoreBarrierElisionPhase.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'Source/JavaScriptCore/dfg/DFGStoreBarrierElisionPhase.cpp')
-rw-r--r--Source/JavaScriptCore/dfg/DFGStoreBarrierElisionPhase.cpp155
1 files changed, 0 insertions, 155 deletions
diff --git a/Source/JavaScriptCore/dfg/DFGStoreBarrierElisionPhase.cpp b/Source/JavaScriptCore/dfg/DFGStoreBarrierElisionPhase.cpp
deleted file mode 100644
index d73c5201e..000000000
--- a/Source/JavaScriptCore/dfg/DFGStoreBarrierElisionPhase.cpp
+++ /dev/null
@@ -1,155 +0,0 @@
-/*
- * 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. AND ITS CONTRIBUTORS ``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 ITS 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 "DFGStoreBarrierElisionPhase.h"
-
-#if ENABLE(DFG_JIT)
-
-#include "DFGBasicBlock.h"
-#include "DFGClobberSet.h"
-#include "DFGGraph.h"
-#include "DFGPhase.h"
-#include <wtf/HashSet.h>
-
-namespace JSC { namespace DFG {
-
-class StoreBarrierElisionPhase : public Phase {
-public:
- StoreBarrierElisionPhase(Graph& graph)
- : Phase(graph, "store barrier elision")
- , m_currentBlock(0)
- , m_currentIndex(0)
- {
- m_gcClobberSet.add(GCState);
- }
-
- bool run()
- {
- for (BlockIndex blockIndex = 0; blockIndex < m_graph.numBlocks(); ++blockIndex) {
- m_currentBlock = m_graph.block(blockIndex);
- if (!m_currentBlock)
- continue;
- handleBlock(m_currentBlock);
- }
- return true;
- }
-
-private:
- bool couldCauseGC(Node* node)
- {
- return writesOverlap(m_graph, node, m_gcClobberSet);
- }
-
- bool allocatesFreshObject(Node* node)
- {
- switch (node->op()) {
- case NewObject:
- case NewArray:
- case NewArrayWithSize:
- case NewArrayBuffer:
- case NewTypedArray:
- case NewRegexp:
- return true;
- default:
- return false;
- }
- }
-
- void noticeFreshObject(HashSet<Node*>& dontNeedBarriers, Node* node)
- {
- ASSERT(allocatesFreshObject(node));
- dontNeedBarriers.add(node);
- }
-
- Node* getBaseOfStore(Node* barrierNode)
- {
- ASSERT(barrierNode->isStoreBarrier());
- return barrierNode->child1().node();
- }
-
- bool shouldBeElided(HashSet<Node*>& dontNeedBarriers, Node* node)
- {
- ASSERT(node->isStoreBarrier());
- return dontNeedBarriers.contains(node->child1().node());
- }
-
- void elideBarrier(Node* node)
- {
- ASSERT(node->isStoreBarrier());
- node->convertToPhantom();
- }
-
- void handleNode(HashSet<Node*>& dontNeedBarriers, Node* node)
- {
- if (couldCauseGC(node))
- dontNeedBarriers.clear();
-
- if (allocatesFreshObject(node))
- noticeFreshObject(dontNeedBarriers, node);
-
- if (!node->isStoreBarrier())
- return;
-
- if (shouldBeElided(dontNeedBarriers, node)) {
- elideBarrier(node);
- return;
- }
-
- Node* base = getBaseOfStore(node);
- if (!base)
- return;
-
- if (dontNeedBarriers.contains(base))
- return;
- dontNeedBarriers.add(base);
- }
-
- bool handleBlock(BasicBlock* block)
- {
- HashSet<Node*> dontNeedBarriers;
- for (unsigned indexInBlock = 0; indexInBlock < block->size(); ++indexInBlock) {
- m_currentIndex = indexInBlock;
- Node* node = block->at(indexInBlock);
- handleNode(dontNeedBarriers, node);
- }
- return true;
- }
-
- ClobberSet m_gcClobberSet;
- BasicBlock* m_currentBlock;
- unsigned m_currentIndex;
-};
-
-bool performStoreBarrierElision(Graph& graph)
-{
- SamplingRegion samplingRegion("DFG Store Barrier Elision Phase");
- return runPhase<StoreBarrierElisionPhase>(graph);
-}
-
-
-} } // namespace JSC::DFG
-
-#endif // ENABLE(DFG_JIT)