| /* |
| * Copyright (C) 2013-2019 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 "DFGStackLayoutPhase.h" |
| |
| #if ENABLE(DFG_JIT) |
| |
| #include "DFGGraph.h" |
| #include "DFGPhase.h" |
| #include "DFGValueSource.h" |
| #include "JSCInlines.h" |
| |
| namespace JSC { namespace DFG { |
| |
| class StackLayoutPhase : public Phase { |
| static constexpr bool verbose = false; |
| |
| public: |
| StackLayoutPhase(Graph& graph) |
| : Phase(graph, "stack layout") |
| { |
| } |
| |
| bool run() |
| { |
| // This enumerates the locals that we actually care about and packs them. So for example |
| // if we use local 1, 3, 4, 5, 7, then we remap them: 1->0, 3->1, 4->2, 5->3, 7->4. We |
| // treat a variable as being "used" if there exists an access to it (SetLocal, GetLocal, |
| // Flush, PhantomLocal). |
| |
| BitVector usedLocals; |
| |
| // Collect those variables that are used from IR. |
| bool hasNodesThatNeedFixup = false; |
| for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) { |
| BasicBlock* block = m_graph.block(blockIndex); |
| if (!block) |
| continue; |
| for (unsigned nodeIndex = block->size(); nodeIndex--;) { |
| Node* node = block->at(nodeIndex); |
| switch (node->op()) { |
| case GetLocal: |
| case SetLocal: |
| case Flush: |
| case PhantomLocal: { |
| VariableAccessData* variable = node->variableAccessData(); |
| if (variable->local().isArgument()) |
| break; |
| usedLocals.set(variable->local().toLocal()); |
| break; |
| } |
| |
| case LoadVarargs: |
| case ForwardVarargs: { |
| LoadVarargsData* data = node->loadVarargsData(); |
| if (data->count.isLocal()) |
| usedLocals.set(data->count.toLocal()); |
| if (data->start.isLocal()) { |
| // This part really relies on the contiguity of stack layout |
| // assignments. |
| ASSERT(VirtualRegister(data->start.offset() + data->limit - 1).isLocal()); |
| for (unsigned i = data->limit; i--;) |
| usedLocals.set(VirtualRegister(data->start.offset() + i).toLocal()); |
| } // the else case shouldn't happen. |
| hasNodesThatNeedFixup = true; |
| break; |
| } |
| |
| case PutStack: |
| case GetStack: { |
| StackAccessData* stack = node->stackAccessData(); |
| if (stack->local.isArgument()) |
| break; |
| usedLocals.set(stack->local.toLocal()); |
| break; |
| } |
| |
| default: |
| break; |
| } |
| } |
| } |
| |
| for (InlineCallFrameSet::iterator iter = m_graph.m_plan.inlineCallFrames()->begin(); !!iter; ++iter) { |
| InlineCallFrame* inlineCallFrame = *iter; |
| |
| if (inlineCallFrame->isVarargs()) { |
| usedLocals.set(VirtualRegister( |
| CallFrameSlot::argumentCount + inlineCallFrame->stackOffset).toLocal()); |
| } |
| |
| for (unsigned argument = inlineCallFrame->argumentsWithFixup.size(); argument--;) { |
| usedLocals.set(VirtualRegister( |
| virtualRegisterForArgument(argument).offset() + |
| inlineCallFrame->stackOffset).toLocal()); |
| } |
| } |
| |
| Vector<unsigned> allocation(usedLocals.size()); |
| m_graph.m_nextMachineLocal = codeBlock()->calleeSaveSpaceAsVirtualRegisters(); |
| for (unsigned i = 0; i < usedLocals.size(); ++i) { |
| if (!usedLocals.get(i)) { |
| allocation[i] = UINT_MAX; |
| continue; |
| } |
| |
| allocation[i] = m_graph.m_nextMachineLocal++; |
| } |
| |
| for (unsigned i = m_graph.m_variableAccessData.size(); i--;) { |
| VariableAccessData* variable = &m_graph.m_variableAccessData[i]; |
| if (!variable->isRoot()) |
| continue; |
| |
| if (variable->local().isArgument()) { |
| variable->machineLocal() = variable->local(); |
| continue; |
| } |
| |
| size_t local = variable->local().toLocal(); |
| if (local >= allocation.size()) |
| continue; |
| |
| if (allocation[local] == UINT_MAX) |
| continue; |
| |
| variable->machineLocal() = assign(allocation, variable->local()); |
| } |
| |
| for (StackAccessData* data : m_graph.m_stackAccessData) { |
| if (!data->local.isLocal()) { |
| data->machineLocal = data->local; |
| continue; |
| } |
| |
| if (static_cast<size_t>(data->local.toLocal()) >= allocation.size()) |
| continue; |
| if (allocation[data->local.toLocal()] == UINT_MAX) |
| continue; |
| |
| data->machineLocal = assign(allocation, data->local); |
| } |
| |
| if (!m_graph.needsScopeRegister()) |
| codeBlock()->setScopeRegister(VirtualRegister()); |
| else |
| codeBlock()->setScopeRegister(assign(allocation, codeBlock()->scopeRegister())); |
| |
| for (unsigned i = m_graph.m_inlineVariableData.size(); i--;) { |
| InlineVariableData data = m_graph.m_inlineVariableData[i]; |
| InlineCallFrame* inlineCallFrame = data.inlineCallFrame; |
| |
| if (inlineCallFrame->isVarargs()) { |
| inlineCallFrame->argumentCountRegister = assign( |
| allocation, VirtualRegister(inlineCallFrame->stackOffset + CallFrameSlot::argumentCount)); |
| } |
| |
| for (unsigned argument = inlineCallFrame->argumentsWithFixup.size(); argument--;) { |
| ArgumentPosition& position = m_graph.m_argumentPositions[ |
| data.argumentPositionStart + argument]; |
| VariableAccessData* variable = position.someVariable(); |
| ValueSource source; |
| if (!variable) |
| source = ValueSource(SourceIsDead); |
| else { |
| source = ValueSource::forFlushFormat( |
| variable->machineLocal(), variable->flushFormat()); |
| } |
| inlineCallFrame->argumentsWithFixup[argument] = source.valueRecovery(); |
| } |
| |
| RELEASE_ASSERT(inlineCallFrame->isClosureCall == !!data.calleeVariable); |
| if (inlineCallFrame->isClosureCall) { |
| VariableAccessData* variable = data.calleeVariable->find(); |
| ValueSource source = ValueSource::forFlushFormat( |
| variable->machineLocal(), |
| variable->flushFormat()); |
| inlineCallFrame->calleeRecovery = source.valueRecovery(); |
| } else |
| RELEASE_ASSERT(inlineCallFrame->calleeRecovery.isConstant()); |
| } |
| |
| // Fix Varargs' variable references. |
| if (hasNodesThatNeedFixup) { |
| for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) { |
| BasicBlock* block = m_graph.block(blockIndex); |
| if (!block) |
| continue; |
| for (unsigned nodeIndex = block->size(); nodeIndex--;) { |
| Node* node = block->at(nodeIndex); |
| switch (node->op()) { |
| case LoadVarargs: |
| case ForwardVarargs: { |
| LoadVarargsData* data = node->loadVarargsData(); |
| data->machineCount = assign(allocation, data->count); |
| data->machineStart = assign(allocation, data->start); |
| break; |
| } |
| |
| default: |
| break; |
| } |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| private: |
| VirtualRegister assign(const Vector<unsigned>& allocation, VirtualRegister src) |
| { |
| VirtualRegister result = src; |
| if (result.isLocal()) { |
| unsigned myAllocation = allocation[result.toLocal()]; |
| if (myAllocation == UINT_MAX) |
| result = VirtualRegister(); |
| else |
| result = virtualRegisterForLocal(myAllocation); |
| } |
| return result; |
| } |
| }; |
| |
| bool performStackLayout(Graph& graph) |
| { |
| return runPhase<StackLayoutPhase>(graph); |
| } |
| |
| } } // namespace JSC::DFG |
| |
| #endif // ENABLE(DFG_JIT) |
| |
