dfg/DFGArgumentsUtilities.cpp

   1 /*
   2  * Copyright (C) 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 "DFGArgumentsUtilities.h"
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include "JSCInlines.h"
  32
  33 namespace JSC { namespace DFG {
  34
  35 bool argumentsInvolveStackSlot(InlineCallFrame* inlineCallFrame, VirtualRegister reg)
  36 {
  37     if (!inlineCallFrame)
  38         return (reg.isArgument() && reg.toArgument()) || reg.isHeader();
  39
  40     if (inlineCallFrame->isClosureCall
  41         && reg == VirtualRegister(inlineCallFrame->stackOffset + JSStack::Callee))
  42         return true;
  43
  44     if (inlineCallFrame->isVarargs()
  45         && reg == VirtualRegister(inlineCallFrame->stackOffset + JSStack::ArgumentCount))
  46         return true;
  47
  48     unsigned numArguments = inlineCallFrame->arguments.size() - 1;
  49     VirtualRegister argumentStart =
  50         VirtualRegister(inlineCallFrame->stackOffset) + CallFrame::argumentOffset(0);
  51     return reg >= argumentStart && reg < argumentStart + numArguments;
  52 }
  53
  54 bool argumentsInvolveStackSlot(Node* candidate, VirtualRegister reg)
  55 {
  56     return argumentsInvolveStackSlot(candidate->origin.semantic.inlineCallFrame, reg);
  57 }
  58
  59 Node* emitCodeToGetArgumentsArrayLength(
  60     InsertionSet& insertionSet, Node* arguments, unsigned nodeIndex, NodeOrigin origin)
  61 {
  62     Graph& graph = insertionSet.graph();
  63
  64     DFG_ASSERT(
  65         graph, arguments,
  66         arguments->op() == CreateDirectArguments || arguments->op() == CreateScopedArguments
  67         || arguments->op() == CreateClonedArguments || arguments->op() == PhantomDirectArguments
  68         || arguments->op() == PhantomClonedArguments);
  69
  70     InlineCallFrame* inlineCallFrame = arguments->origin.semantic.inlineCallFrame;
  71
  72     if (inlineCallFrame && !inlineCallFrame->isVarargs()) {
  73         return insertionSet.insertConstant(
  74             nodeIndex, origin, jsNumber(inlineCallFrame->arguments.size() - 1));
  75     }
  76
  77     Node* argumentCount;
  78     if (!inlineCallFrame)
  79         argumentCount = insertionSet.insertNode(nodeIndex, SpecInt32, GetArgumentCount, origin);
  80     else {
  81         VirtualRegister argumentCountRegister(inlineCallFrame->stackOffset + JSStack::ArgumentCount);
  82
  83         argumentCount = insertionSet.insertNode(
  84             nodeIndex, SpecInt32, GetStack, origin,
  85             OpInfo(graph.m_stackAccessData.add(argumentCountRegister, FlushedInt32)));
  86     }
  87
  88     return insertionSet.insertNode(
  89         nodeIndex, SpecInt32, ArithSub, origin, OpInfo(Arith::Unchecked),
  90         Edge(argumentCount, Int32Use),
  91         insertionSet.insertConstantForUse(
  92             nodeIndex, origin, jsNumber(1), Int32Use));
  93 }
  94
  95 } } // namespace JSC::DFG
  96
  97 #endif // ENABLE(DFG_JIT)
  98