dfg/DFGTierUpCheckInjectionPhase.cpp

   1 /*
   2  * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27 #include "DFGTierUpCheckInjectionPhase.h"
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include "DFGGraph.h"
  32 #include "DFGInsertionSet.h"
  33 #include "DFGPhase.h"
  34 #include "FTLCapabilities.h"
  35 #include "JSCInlines.h"
  36
  37 namespace JSC { namespace DFG {
  38
  39 class TierUpCheckInjectionPhase : public Phase {
  40 public:
  41     TierUpCheckInjectionPhase(Graph& graph)
  42         : Phase(graph, "tier-up check injection")
  43     {
  44     }
  45
  46     bool run()
  47     {
  48         RELEASE_ASSERT(m_graph.m_plan.mode == DFGMode);
  49
  50         if (!Options::useFTLJIT())
  51             return false;
  52
  53         if (m_graph.m_profiledBlock->m_didFailFTLCompilation)
  54             return false;
  55
  56 #if ENABLE(FTL_JIT)
  57         FTL::CapabilityLevel level = FTL::canCompile(m_graph);
  58         if (level == FTL::CannotCompile)
  59             return false;
  60
  61         if (!Options::enableOSREntryToFTL())
  62             level = FTL::CanCompile;
  63
  64         // First we find all the loops that contain a LoopHint for which we cannot OSR enter.
  65         // We use that information to decide if we need CheckTierUpAndOSREnter or CheckTierUpWithNestedTriggerAndOSREnter.
  66         NaturalLoops& naturalLoops = m_graph.m_naturalLoops;
  67         naturalLoops.computeIfNecessary(m_graph);
  68
  69         HashSet<const NaturalLoop*> loopsContainingLoopHintWithoutOSREnter = findLoopsContainingLoopHintWithoutOSREnter(naturalLoops, level);
  70
  71         InsertionSet insertionSet(m_graph);
  72         for (BlockIndex blockIndex = m_graph.numBlocks(); blockIndex--;) {
  73             BasicBlock* block = m_graph.block(blockIndex);
  74             if (!block)
  75                 continue;
  76
  77             for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
  78                 Node* node = block->at(nodeIndex);
  79                 if (node->op() != LoopHint)
  80                     continue;
  81
  82                 NodeOrigin origin = node->origin;
  83                 if (canOSREnterAtLoopHint(level, block, nodeIndex)) {
  84                     const NaturalLoop* loop = naturalLoops.innerMostLoopOf(block);
  85                     if (loop && loopsContainingLoopHintWithoutOSREnter.contains(loop))
  86                         insertionSet.insertNode(nodeIndex + 1, SpecNone, CheckTierUpWithNestedTriggerAndOSREnter, origin);
  87                     else
  88                         insertionSet.insertNode(nodeIndex + 1, SpecNone, CheckTierUpAndOSREnter, origin);
  89                 } else
  90                     insertionSet.insertNode(nodeIndex + 1, SpecNone, CheckTierUpInLoop, origin);
  91                 break;
  92             }
  93
  94             NodeAndIndex terminal = block->findTerminal();
  95             if (terminal.node->op() == Return) {
  96                 insertionSet.insertNode(
  97                     terminal.index, SpecNone, CheckTierUpAtReturn, terminal.node->origin);
  98             }
  99
 100             insertionSet.execute(block);
 101         }
 102
 103         m_graph.m_plan.willTryToTierUp = true;
 104         return true;
 105 #else // ENABLE(FTL_JIT)
 106         RELEASE_ASSERT_NOT_REACHED();
 107         return false;
 108 #endif // ENABLE(FTL_JIT)
 109     }
 110
 111 private:
 112 #if ENABLE(FTL_JIT)
 113     bool canOSREnterAtLoopHint(FTL::CapabilityLevel level, const BasicBlock* block, unsigned nodeIndex)
 114     {
 115         Node* node = block->at(nodeIndex);
 116         ASSERT(node->op() == LoopHint);
 117
 118         NodeOrigin origin = node->origin;
 119         if (level != FTL::CanCompileAndOSREnter || origin.semantic.inlineCallFrame)
 120             return false;
 121
 122         // We only put OSR checks for the first LoopHint in the block. Note that
 123         // more than one LoopHint could happen in cases where we did a lot of CFG
 124         // simplification in the bytecode parser, but it should be very rare.
 125         for (unsigned subNodeIndex = nodeIndex; subNodeIndex--;) {
 126             if (!block->at(subNodeIndex)->isSemanticallySkippable())
 127                 return false;
 128         }
 129         return true;
 130     }
 131
 132     HashSet<const NaturalLoop*> findLoopsContainingLoopHintWithoutOSREnter(const NaturalLoops& naturalLoops, FTL::CapabilityLevel level)
 133     {
 134         HashSet<const NaturalLoop*> loopsContainingLoopHintWithoutOSREnter;
 135         for (BasicBlock* block : m_graph.blocksInNaturalOrder()) {
 136             for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) {
 137                 Node* node = block->at(nodeIndex);
 138                 if (node->op() != LoopHint)
 139                     continue;
 140
 141                 if (!canOSREnterAtLoopHint(level, block, nodeIndex)) {
 142                     const NaturalLoop* loop = naturalLoops.innerMostLoopOf(block);
 143                     while (loop) {
 144                         loopsContainingLoopHintWithoutOSREnter.add(loop);
 145                         loop = naturalLoops.innerMostOuterLoop(*loop);
 146                     }
 147                 }
 148             }
 149         }
 150         return loopsContainingLoopHintWithoutOSREnter;
 151     }
 152 #endif
 153 };
 154
 155 bool performTierUpCheckInjection(Graph& graph)
 156 {
 157     SamplingRegion samplingRegion("DFG Tier-up Check Injection");
 158     return runPhase<TierUpCheckInjectionPhase>(graph);
 159 }
 160
 161 } } // namespace JSC::DFG
 162
 163 #endif // ENABLE(DFG_JIT)
 164
 165