1 files changed, 173 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/dfg/DFGTierUpCheckInjectionPhase.cpp b/Source/JavaScriptCore/dfg/DFGTierUpCheckInjectionPhase.cpp
new file mode 100644
index 000000000..9b14a9820
--- /dev/null
+++ b/Source/JavaScriptCore/dfg/DFGTierUpCheckInjectionPhase.cpp
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2013-2015 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 "DFGTierUpCheckInjectionPhase.h"
+
+#if ENABLE(DFG_JIT)
+
+#include "DFGGraph.h"
+#include "DFGInsertionSet.h"
+#include "DFGNaturalLoops.h"
+#include "DFGPhase.h"
+#include "FTLCapabilities.h"
+#include "JSCInlines.h"
+
+namespace JSC { namespace DFG {
+
+class TierUpCheckInjectionPhase : public Phase {
+public:
+    TierUpCheckInjectionPhase(Graph& graph)
+        : Phase(graph, "tier-up check injection")
+    {
+    }
+    
+    bool run()
+    {
+        RELEASE_ASSERT(m_graph.m_plan.mode == DFGMode);
+        
+        if (!Options::useFTLJIT())
+            return false;
+        
+        if (m_graph.m_profiledBlock->m_didFailFTLCompilation)
+            return false;
+
+        if (!Options::bytecodeRangeToFTLCompile().isInRange(m_graph.m_profiledBlock->instructionCount()))
+            return false;
+
+#if ENABLE(FTL_JIT)
+        FTL::CapabilityLevel level = FTL::canCompile(m_graph);
+        if (level == FTL::CannotCompile)
+            return false;
+        
+        if (!Options::useOSREntryToFTL())
+            level = FTL::CanCompile;
+
+        // First we find all the loops that contain a LoopHint for which we cannot OSR enter.
+        // We use that information to decide if we need CheckTierUpAndOSREnter or CheckTierUpWithNestedTriggerAndOSREnter.
+        m_graph.ensureNaturalLoops();
+        NaturalLoops& naturalLoops = *m_graph.m_naturalLoops;
+
+        HashSet<const NaturalLoop*> loopsContainingLoopHintWithoutOSREnter = findLoopsContainingLoopHintWithoutOSREnter(naturalLoops, level);
+
+        bool canTierUpAndOSREnter = false;
+        
+        InsertionSet insertionSet(m_graph);
+        for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
+            BasicBlock* block = m_graph.block(blockIndex);
+            if (!block)
+                continue;
+            
+            for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
+                Node* node = block->at(nodeIndex);
+                if (node->op() != LoopHint)
+                    continue;
+
+                NodeOrigin origin = node->origin;
+                if (canOSREnterAtLoopHint(level, block, nodeIndex)) {
+                    canTierUpAndOSREnter = true;
+                    const NaturalLoop* loop = naturalLoops.innerMostLoopOf(block);
+                    if (loop && loopsContainingLoopHintWithoutOSREnter.contains(loop))
+                        insertionSet.insertNode(nodeIndex + 1, SpecNone, CheckTierUpWithNestedTriggerAndOSREnter, origin);
+                    else
+                        insertionSet.insertNode(nodeIndex + 1, SpecNone, CheckTierUpAndOSREnter, origin);
+                } else
+                    insertionSet.insertNode(nodeIndex + 1, SpecNone, CheckTierUpInLoop, origin);
+                break;
+            }
+            
+            NodeAndIndex terminal = block->findTerminal();
+            if (terminal.node->isFunctionTerminal()) {
+                insertionSet.insertNode(
+                    terminal.index, SpecNone, CheckTierUpAtReturn, terminal.node->origin);
+            }
+            
+            insertionSet.execute(block);
+        }
+
+        m_graph.m_plan.canTierUpAndOSREnter = canTierUpAndOSREnter;
+        m_graph.m_plan.willTryToTierUp = true;
+        return true;
+#else // ENABLE(FTL_JIT)
+        RELEASE_ASSERT_NOT_REACHED();
+        return false;
+#endif // ENABLE(FTL_JIT)
+    }
+
+private:
+#if ENABLE(FTL_JIT)
+    bool canOSREnterAtLoopHint(FTL::CapabilityLevel level, const BasicBlock* block, unsigned nodeIndex)
+    {
+        Node* node = block->at(nodeIndex);
+        ASSERT(node->op() == LoopHint);
+
+        NodeOrigin origin = node->origin;
+        if (level != FTL::CanCompileAndOSREnter || origin.semantic.inlineCallFrame)
+            return false;
+
+        // We only put OSR checks for the first LoopHint in the block. Note that
+        // more than one LoopHint could happen in cases where we did a lot of CFG
+        // simplification in the bytecode parser, but it should be very rare.
+        for (unsigned subNodeIndex = nodeIndex; subNodeIndex--;) {
+            if (!block->at(subNodeIndex)->isSemanticallySkippable())
+                return false;
+        }
+        return true;
+    }
+
+    HashSet<const NaturalLoop*> findLoopsContainingLoopHintWithoutOSREnter(const NaturalLoops& naturalLoops, FTL::CapabilityLevel level)
+    {
+        HashSet<const NaturalLoop*> loopsContainingLoopHintWithoutOSREnter;
+        for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
+            for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
+                Node* node = block->at(nodeIndex);
+                if (node->op() != LoopHint)
+                    continue;
+
+                if (!canOSREnterAtLoopHint(level, block, nodeIndex)) {
+                    const NaturalLoop* loop = naturalLoops.innerMostLoopOf(block);
+                    while (loop) {
+                        loopsContainingLoopHintWithoutOSREnter.add(loop);
+                        loop = naturalLoops.innerMostOuterLoop(*loop);
+                    }
+                }
+            }
+        }
+        return loopsContainingLoopHintWithoutOSREnter;
+    }
+#endif
+};
+
+bool performTierUpCheckInjection(Graph& graph)
+{
+    SamplingRegion samplingRegion("DFG Tier-up Check Injection");
+    return runPhase<TierUpCheckInjectionPhase>(graph);
+}
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+
+