dfg/DFGSaneStringGetByValSlowPathGenerator.h

   1 /*
   2  * Copyright (C) 2013 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 #ifndef DFGSaneStringGetByValSlowPathGenerator_h
  27 #define DFGSaneStringGetByValSlowPathGenerator_h
  28
  29 #if ENABLE(DFG_JIT)
  30
  31 #include "DFGCommon.h"
  32 #include "DFGOperations.h"
  33 #include "DFGSlowPathGenerator.h"
  34 #include "DFGSpeculativeJIT.h"
  35 #include <wtf/Vector.h>
  36
  37 namespace JSC { namespace DFG {
  38
  39 class SaneStringGetByValSlowPathGenerator : public JumpingSlowPathGenerator<MacroAssembler::Jump> {
  40 public:
  41     SaneStringGetByValSlowPathGenerator(
  42         const MacroAssembler::Jump& from, SpeculativeJIT* jit, JSValueRegs resultRegs,
  43         GPRReg baseReg, GPRReg propertyReg)
  44         : JumpingSlowPathGenerator<MacroAssembler::Jump>(from, jit)
  45         , m_resultRegs(resultRegs)
  46         , m_baseReg(baseReg)
  47         , m_propertyReg(propertyReg)
  48     {
  49         jit->silentSpillAllRegistersImpl(false, m_plans, extractResult(resultRegs));
  50     }
  51
  52 protected:
  53     virtual void generateInternal(SpeculativeJIT* jit) override
  54     {
  55         linkFrom(jit);
  56
  57         MacroAssembler::Jump isNeg = jit->m_jit.branch32(
  58             MacroAssembler::LessThan, m_propertyReg, MacroAssembler::TrustedImm32(0));
  59
  60 #if USE(JSVALUE64)
  61         jit->m_jit.move(
  62             MacroAssembler::TrustedImm64(JSValue::encode(jsUndefined())), m_resultRegs.gpr());
  63 #else
  64         jit->m_jit.move(
  65             MacroAssembler::TrustedImm32(JSValue::UndefinedTag), m_resultRegs.tagGPR());
  66         jit->m_jit.move(
  67             MacroAssembler::TrustedImm32(0), m_resultRegs.payloadGPR());
  68 #endif
  69         jumpTo(jit);
  70
  71         isNeg.link(&jit->m_jit);
  72
  73         for (unsigned i = 0; i < m_plans.size(); ++i)
  74             jit->silentSpill(m_plans[i]);
  75         jit->callOperation(operationGetByValStringInt, extractResult(m_resultRegs), m_baseReg, m_propertyReg);
  76         GPRReg canTrample = SpeculativeJIT::pickCanTrample(extractResult(m_resultRegs));
  77         for (unsigned i = m_plans.size(); i--;)
  78             jit->silentFill(m_plans[i], canTrample);
  79
  80         jumpTo(jit);
  81     }
  82
  83 private:
  84     JSValueRegs m_resultRegs;
  85     GPRReg m_baseReg;
  86     GPRReg m_propertyReg;
  87     Vector<SilentRegisterSavePlan, 2> m_plans;
  88 };
  89
  90 } } // namespace JSC::DFG
  91
  92 #endif // ENABLE(DFG_JIT)
  93
  94 #endif // DFGSaneStringGetByValSlowPathGenerator_h
  95