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Diffstat (limited to 'Source/JavaScriptCore/dfg/DFGRedundantPhiEliminationPhase.cpp')
| -rw-r--r-- | Source/JavaScriptCore/dfg/DFGRedundantPhiEliminationPhase.cpp | 178 |
1 files changed, 0 insertions, 178 deletions
diff --git a/Source/JavaScriptCore/dfg/DFGRedundantPhiEliminationPhase.cpp b/Source/JavaScriptCore/dfg/DFGRedundantPhiEliminationPhase.cpp deleted file mode 100644 index 32e4ef157..000000000 --- a/Source/JavaScriptCore/dfg/DFGRedundantPhiEliminationPhase.cpp +++ /dev/null @@ -1,178 +0,0 @@ -/* - * Copyright (C) 2012 Intel Corporation. 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 "DFGRedundantPhiEliminationPhase.h" - -#if ENABLE(DFG_JIT) - -#include "DFGGraph.h" - -namespace JSC { namespace DFG { - -class RedundantPhiEliminationPhase : public Phase { -public: - RedundantPhiEliminationPhase(Graph& graph) - : Phase(graph, "redundant phi elimination") - { - } - - bool run() - { - bool changed = false; - do { - changed = fixupPhis(); - } while (changed); - - updateBlockVariableInformation(); - - // Update the Phi references from non-Phi nodes, e.g., the GetLocals. - for (NodeIndex index = 0; index < m_graph.size(); ++index) { - Node& node = m_graph[index]; - - if (!node.shouldGenerate()) - continue; - - switch (node.op()) { - case GetLocal: - replacePhiChild(node, 0); - break; - default: - break; - } - } - - return true; - } - -private: - NodeIndex getRedundantReplacement(NodeIndex phi) - { - NodeIndex child1 = m_graph[phi].child1().indexUnchecked(); - NodeIndex candidate = child1 == phi ? NoNode : child1; - - NodeIndex child2 = m_graph[phi].child2().indexUnchecked(); - if (candidate != NoNode) { - if (child2 != NoNode && child2 != candidate && child2 != phi) - return NoNode; - } else if (child2 != phi) - candidate = child2; - - NodeIndex child3 = m_graph[phi].child3().indexUnchecked(); - if (candidate != NoNode) { - if (child3 != NoNode && child3 != candidate && child3 != phi) - return NoNode; - } else if (child3 != phi) - candidate = child3; - - return candidate; - } - - bool replacePhiChild(Node& node, unsigned childIndex) - { - ASSERT(childIndex < 3); - - bool replaced = false; - NodeIndex child = node.children.child(childIndex).indexUnchecked(); - if (child != NoNode && m_graph[child].op() == Phi) { - NodeIndex childReplacement = getRedundantReplacement(child); - if (childReplacement != NoNode) { - node.children.child(childIndex).setIndex(childReplacement); - replaced = true; - if (node.refCount()) { - m_graph[childReplacement].ref(); - m_graph.deref(child); - } - } - } - return replaced; - } - - bool fixupPhis() - { - bool changed = false; - - for (BlockIndex block = 0; block < m_graph.m_blocks.size(); ++block) { - Vector<NodeIndex>& phis = m_graph.m_blocks[block]->phis; - - for (size_t i = 0; i < phis.size(); ++i) { - NodeIndex phi = phis[i]; - Node& phiNode = m_graph[phi]; - - changed |= (replacePhiChild(phiNode, 0) && phiNode.refCount()); - changed |= (replacePhiChild(phiNode, 1) && phiNode.refCount()); - changed |= (replacePhiChild(phiNode, 2) && phiNode.refCount()); - } - } - - return changed; - } - - void updateBlockVariableInformation() - { - // Redundant Phi nodes are eliminated, we need to update - // the variable information if it references them. - for (BlockIndex blockIndex = 0; blockIndex < m_graph.m_blocks.size(); ++blockIndex) { - BasicBlock* basicBlock = m_graph.m_blocks[blockIndex].get(); - - for (size_t arg = 0; arg < basicBlock->variablesAtHead.numberOfArguments(); ++arg) { - NodeIndex nodeIndex = basicBlock->variablesAtHead.argument(arg); - if (nodeIndex != NoNode && m_graph[nodeIndex].op() == Phi && !m_graph[nodeIndex].refCount()) { - NodeIndex replacement = getRedundantReplacement(nodeIndex); - if (replacement != NoNode) { - // This argument must be unused in this block. - ASSERT(basicBlock->variablesAtTail.argument(arg) == nodeIndex); - basicBlock->variablesAtHead.argument(arg) = replacement; - basicBlock->variablesAtTail.argument(arg) = replacement; - } - } - } - - for (size_t local = 0; local < basicBlock->variablesAtHead.numberOfLocals(); ++local) { - NodeIndex nodeIndex = basicBlock->variablesAtHead.local(local); - if (nodeIndex != NoNode && m_graph[nodeIndex].op() == Phi && !m_graph[nodeIndex].refCount()) { - NodeIndex replacement = getRedundantReplacement(nodeIndex); - if (replacement != NoNode) { - // This local variable must be unused in this block. - ASSERT(basicBlock->variablesAtTail.local(local) == nodeIndex); - basicBlock->variablesAtHead.local(local) = replacement; - basicBlock->variablesAtTail.local(local) = replacement; - } - } - } - } - } - -}; - -bool performRedundantPhiElimination(Graph& graph) -{ - SamplingRegion samplingRegion("DFG Redundant Phi Elimination Phase"); - return runPhase<RedundantPhiEliminationPhase>(graph); -} - -} } // namespace JSC::DFG - -#endif // ENABLE(DFG_JIT) |