bytecode/PutByIdStatus.cpp

   1 /*
   2  * Copyright (C) 2012 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 "PutByIdStatus.h"
  28
  29 #include "CodeBlock.h"
  30 #include "LowLevelInterpreter.h"
  31 #include "Structure.h"
  32 #include "StructureChain.h"
  33
  34 namespace JSC {
  35
  36 PutByIdStatus PutByIdStatus::computeFromLLInt(CodeBlock* profiledBlock, unsigned bytecodeIndex, Identifier& ident)
  37 {
  38     UNUSED_PARAM(profiledBlock);
  39     UNUSED_PARAM(bytecodeIndex);
  40     UNUSED_PARAM(ident);
  41 #if ENABLE(LLINT)
  42     Instruction* instruction = profiledBlock->instructions().begin() + bytecodeIndex;
  43
  44     Structure* structure = instruction[4].u.structure.get();
  45     if (!structure)
  46         return PutByIdStatus(NoInformation, 0, 0, 0, notFound);
  47
  48     if (instruction[0].u.opcode == llint_op_put_by_id) {
  49         size_t offset = structure->get(*profiledBlock->globalData(), ident);
  50         if (offset == notFound)
  51             return PutByIdStatus(NoInformation, 0, 0, 0, notFound);
  52
  53         return PutByIdStatus(SimpleReplace, structure, 0, 0, offset);
  54     }
  55
  56     ASSERT(instruction[0].u.opcode == llint_op_put_by_id_transition_direct
  57            || instruction[0].u.opcode == llint_op_put_by_id_transition_normal);
  58
  59     Structure* newStructure = instruction[6].u.structure.get();
  60     StructureChain* chain = instruction[7].u.structureChain.get();
  61     ASSERT(newStructure);
  62     ASSERT(chain);
  63
  64     size_t offset = newStructure->get(*profiledBlock->globalData(), ident);
  65     if (offset == notFound)
  66         return PutByIdStatus(NoInformation, 0, 0, 0, notFound);
  67
  68     return PutByIdStatus(SimpleTransition, structure, newStructure, chain, offset);
  69 #else
  70     return PutByIdStatus(NoInformation, 0, 0, 0, notFound);
  71 #endif
  72 }
  73
  74 PutByIdStatus PutByIdStatus::computeFor(CodeBlock* profiledBlock, unsigned bytecodeIndex, Identifier& ident)
  75 {
  76     UNUSED_PARAM(profiledBlock);
  77     UNUSED_PARAM(bytecodeIndex);
  78     UNUSED_PARAM(ident);
  79 #if ENABLE(JIT) && ENABLE(VALUE_PROFILER)
  80     if (!profiledBlock->numberOfStructureStubInfos())
  81         return computeFromLLInt(profiledBlock, bytecodeIndex, ident);
  82
  83     if (profiledBlock->likelyToTakeSlowCase(bytecodeIndex))
  84         return PutByIdStatus(TakesSlowPath, 0, 0, 0, notFound);
  85
  86     StructureStubInfo& stubInfo = profiledBlock->getStubInfo(bytecodeIndex);
  87     if (!stubInfo.seen)
  88         return computeFromLLInt(profiledBlock, bytecodeIndex, ident);
  89
  90     switch (stubInfo.accessType) {
  91     case access_unset:
  92         return computeFromLLInt(profiledBlock, bytecodeIndex, ident);
  93
  94     case access_put_by_id_replace: {
  95         size_t offset = stubInfo.u.putByIdReplace.baseObjectStructure->get(
  96             *profiledBlock->globalData(), ident);
  97         if (offset != notFound) {
  98             return PutByIdStatus(
  99                 SimpleReplace,
 100                 stubInfo.u.putByIdReplace.baseObjectStructure.get(),
 101                 0, 0,
 102                 offset);
 103         }
 104         return PutByIdStatus(TakesSlowPath, 0, 0, 0, notFound);
 105     }
 106
 107     case access_put_by_id_transition_normal:
 108     case access_put_by_id_transition_direct: {
 109         size_t offset = stubInfo.u.putByIdTransition.structure->get(
 110             *profiledBlock->globalData(), ident);
 111         if (offset != notFound) {
 112             return PutByIdStatus(
 113                 SimpleTransition,
 114                 stubInfo.u.putByIdTransition.previousStructure.get(),
 115                 stubInfo.u.putByIdTransition.structure.get(),
 116                 stubInfo.u.putByIdTransition.chain.get(),
 117                 offset);
 118         }
 119         return PutByIdStatus(TakesSlowPath, 0, 0, 0, notFound);
 120     }
 121
 122     default:
 123         return PutByIdStatus(TakesSlowPath, 0, 0, 0, notFound);
 124     }
 125 #else // ENABLE(JIT)
 126     return PutByIdStatus(NoInformation, 0, 0, 0, notFound);
 127 #endif // ENABLE(JIT)
 128 }
 129
 130 } // namespace JSC
 131