dfg/DFGBasicBlock.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 "DFGBasicBlock.h"
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include "JSCInlines.h"
  32
  33 namespace JSC { namespace DFG {
  34
  35 BasicBlock::BasicBlock(
  36     unsigned bytecodeBegin, unsigned numArguments, unsigned numLocals, float executionCount)
  37     : bytecodeBegin(bytecodeBegin)
  38     , index(NoBlock)
  39     , isOSRTarget(false)
  40     , cfaHasVisited(false)
  41     , cfaShouldRevisit(false)
  42     , cfaFoundConstants(false)
  43     , cfaDidFinish(true)
  44     , cfaStructureClobberStateAtHead(StructuresAreWatched)
  45     , cfaStructureClobberStateAtTail(StructuresAreWatched)
  46     , cfaBranchDirection(InvalidBranchDirection)
  47 #if !ASSERT_DISABLED
  48     , isLinked(false)
  49 #endif
  50     , isReachable(false)
  51     , variablesAtHead(numArguments, numLocals)
  52     , variablesAtTail(numArguments, numLocals)
  53     , valuesAtHead(numArguments, numLocals)
  54     , valuesAtTail(numArguments, numLocals)
  55     , intersectionOfPastValuesAtHead(numArguments, numLocals, AbstractValue::fullTop())
  56     , intersectionOfCFAHasVisited(true)
  57     , executionCount(executionCount)
  58 {
  59 }
  60
  61 BasicBlock::~BasicBlock()
  62 {
  63 }
  64
  65 void BasicBlock::ensureLocals(unsigned newNumLocals)
  66 {
  67     variablesAtHead.ensureLocals(newNumLocals);
  68     variablesAtTail.ensureLocals(newNumLocals);
  69     valuesAtHead.ensureLocals(newNumLocals);
  70     valuesAtTail.ensureLocals(newNumLocals);
  71     intersectionOfPastValuesAtHead.ensureLocals(newNumLocals, AbstractValue::fullTop());
  72 }
  73
  74 void BasicBlock::replaceTerminal(Node* node)
  75 {
  76     NodeAndIndex result = findTerminal();
  77     if (!result)
  78         append(node);
  79     else {
  80         m_nodes.insert(result.index + 1, node);
  81         result.node->remove();
  82     }
  83
  84     ASSERT(terminal());
  85 }
  86
  87 bool BasicBlock::isInPhis(Node* node) const
  88 {
  89     for (size_t i = 0; i < phis.size(); ++i) {
  90         if (phis[i] == node)
  91             return true;
  92     }
  93     return false;
  94 }
  95
  96 bool BasicBlock::isInBlock(Node* myNode) const
  97 {
  98     for (size_t i = 0; i < numNodes(); ++i) {
  99         if (node(i) == myNode)
 100             return true;
 101     }
 102     return false;
 103 }
 104
 105 Node* BasicBlock::firstOriginNode()
 106 {
 107     for (Node* node : *this) {
 108         if (node->origin.isSet())
 109             return node;
 110     }
 111     RELEASE_ASSERT_NOT_REACHED();
 112     return nullptr;
 113 }
 114
 115 NodeOrigin BasicBlock::firstOrigin()
 116 {
 117     return firstOriginNode()->origin;
 118 }
 119
 120 void BasicBlock::removePredecessor(BasicBlock* block)
 121 {
 122     for (unsigned i = 0; i < predecessors.size(); ++i) {
 123         if (predecessors[i] != block)
 124             continue;
 125         predecessors[i] = predecessors.last();
 126         predecessors.removeLast();
 127         return;
 128     }
 129     RELEASE_ASSERT_NOT_REACHED();
 130 }
 131
 132 void BasicBlock::replacePredecessor(BasicBlock* from, BasicBlock* to)
 133 {
 134     for (unsigned i = predecessors.size(); i--;) {
 135         if (predecessors[i] != from)
 136             continue;
 137         predecessors[i] = to;
 138         return;
 139     }
 140     RELEASE_ASSERT_NOT_REACHED();
 141 }
 142
 143 void BasicBlock::dump(PrintStream& out) const
 144 {
 145     out.print("#", index);
 146 }
 147
 148 BasicBlock::SSAData::SSAData(BasicBlock* block)
 149 {
 150     availabilityAtHead.m_locals = Operands<Availability>(OperandsLike, block->variablesAtHead);
 151     availabilityAtTail.m_locals = Operands<Availability>(OperandsLike, block->variablesAtHead);
 152 }
 153
 154 BasicBlock::SSAData::~SSAData() { }
 155
 156 } } // namespace JSC::DFG
 157
 158 #endif // ENABLE(DFG_JIT)
 159