jit/SetupVarargsFrame.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 "SetupVarargsFrame.h"
  28
  29 #if ENABLE(JIT)
  30
  31 #include "Interpreter.h"
  32 #include "JSCInlines.h"
  33 #include "StackAlignment.h"
  34
  35 namespace JSC {
  36
  37 void emitSetVarargsFrame(CCallHelpers& jit, GPRReg lengthGPR, bool lengthIncludesThis, GPRReg numUsedSlotsGPR, GPRReg resultGPR)
  38 {
  39     jit.move(numUsedSlotsGPR, resultGPR);
  40     jit.addPtr(lengthGPR, resultGPR);
  41     jit.addPtr(CCallHelpers::TrustedImm32(JSStack::CallFrameHeaderSize + (lengthIncludesThis? 0 : 1)), resultGPR);
  42
  43     // resultGPR now has the required frame size in Register units
  44     // Round resultGPR to next multiple of stackAlignmentRegisters()
  45     jit.addPtr(CCallHelpers::TrustedImm32(stackAlignmentRegisters() - 1), resultGPR);
  46     jit.andPtr(CCallHelpers::TrustedImm32(~(stackAlignmentRegisters() - 1)), resultGPR);
  47
  48     // Now resultGPR has the right stack frame offset in Register units.
  49     jit.negPtr(resultGPR);
  50     jit.lshiftPtr(CCallHelpers::Imm32(3), resultGPR);
  51     jit.addPtr(GPRInfo::callFrameRegister, resultGPR);
  52 }
  53
  54 void emitSetupVarargsFrameFastCase(CCallHelpers& jit, GPRReg numUsedSlotsGPR, GPRReg scratchGPR1, GPRReg scratchGPR2, GPRReg scratchGPR3, ValueRecovery argCountRecovery, VirtualRegister firstArgumentReg, unsigned firstVarArgOffset, CCallHelpers::JumpList& slowCase)
  55 {
  56     CCallHelpers::JumpList end;
  57
  58     if (argCountRecovery.isConstant()) {
  59         // FIXME: We could constant-fold a lot of the computation below in this case.
  60         // https://bugs.webkit.org/show_bug.cgi?id=141486
  61         jit.move(CCallHelpers::TrustedImm32(argCountRecovery.constant().asInt32()), scratchGPR1);
  62     } else
  63         jit.load32(CCallHelpers::payloadFor(argCountRecovery.virtualRegister()), scratchGPR1);
  64     if (firstVarArgOffset) {
  65         CCallHelpers::Jump sufficientArguments = jit.branch32(CCallHelpers::GreaterThan, scratchGPR1, CCallHelpers::TrustedImm32(firstVarArgOffset + 1));
  66         jit.move(CCallHelpers::TrustedImm32(1), scratchGPR1);
  67         CCallHelpers::Jump endVarArgs = jit.jump();
  68         sufficientArguments.link(&jit);
  69         jit.sub32(CCallHelpers::TrustedImm32(firstVarArgOffset), scratchGPR1);
  70         endVarArgs.link(&jit);
  71     }
  72     slowCase.append(jit.branch32(CCallHelpers::Above, scratchGPR1, CCallHelpers::TrustedImm32(maxArguments + 1)));
  73
  74     emitSetVarargsFrame(jit, scratchGPR1, true, numUsedSlotsGPR, scratchGPR2);
  75
  76     slowCase.append(jit.branchPtr(CCallHelpers::Above, CCallHelpers::AbsoluteAddress(jit.vm()->addressOfStackLimit()), scratchGPR2));
  77
  78     // Initialize ArgumentCount.
  79     jit.store32(scratchGPR1, CCallHelpers::Address(scratchGPR2, JSStack::ArgumentCount * static_cast<int>(sizeof(Register)) + PayloadOffset));
  80
  81     // Copy arguments.
  82     jit.signExtend32ToPtr(scratchGPR1, scratchGPR1);
  83     CCallHelpers::Jump done = jit.branchSubPtr(CCallHelpers::Zero, CCallHelpers::TrustedImm32(1), scratchGPR1);
  84     // scratchGPR1: argumentCount
  85
  86     CCallHelpers::Label copyLoop = jit.label();
  87     int argOffset = (firstArgumentReg.offset() - 1 + firstVarArgOffset) * static_cast<int>(sizeof(Register));
  88 #if USE(JSVALUE64)
  89     jit.load64(CCallHelpers::BaseIndex(GPRInfo::callFrameRegister, scratchGPR1, CCallHelpers::TimesEight, argOffset), scratchGPR3);
  90     jit.store64(scratchGPR3, CCallHelpers::BaseIndex(scratchGPR2, scratchGPR1, CCallHelpers::TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));
  91 #else // USE(JSVALUE64), so this begins the 32-bit case
  92     jit.load32(CCallHelpers::BaseIndex(GPRInfo::callFrameRegister, scratchGPR1, CCallHelpers::TimesEight, argOffset + TagOffset), scratchGPR3);
  93     jit.store32(scratchGPR3, CCallHelpers::BaseIndex(scratchGPR2, scratchGPR1, CCallHelpers::TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)) + TagOffset));
  94     jit.load32(CCallHelpers::BaseIndex(GPRInfo::callFrameRegister, scratchGPR1, CCallHelpers::TimesEight, argOffset + PayloadOffset), scratchGPR3);
  95     jit.store32(scratchGPR3, CCallHelpers::BaseIndex(scratchGPR2, scratchGPR1, CCallHelpers::TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)) + PayloadOffset));
  96 #endif // USE(JSVALUE64), end of 32-bit case
  97     jit.branchSubPtr(CCallHelpers::NonZero, CCallHelpers::TrustedImm32(1), scratchGPR1).linkTo(copyLoop, &jit);
  98
  99     done.link(&jit);
 100 }
 101
 102 void emitSetupVarargsFrameFastCase(CCallHelpers& jit, GPRReg numUsedSlotsGPR, GPRReg scratchGPR1, GPRReg scratchGPR2, GPRReg scratchGPR3, unsigned firstVarArgOffset, CCallHelpers::JumpList& slowCase)
 103 {
 104     emitSetupVarargsFrameFastCase(jit, numUsedSlotsGPR, scratchGPR1, scratchGPR2, scratchGPR3, nullptr, firstVarArgOffset, slowCase);
 105 }
 106
 107 void emitSetupVarargsFrameFastCase(CCallHelpers& jit, GPRReg numUsedSlotsGPR, GPRReg scratchGPR1, GPRReg scratchGPR2, GPRReg scratchGPR3, InlineCallFrame* inlineCallFrame, unsigned firstVarArgOffset, CCallHelpers::JumpList& slowCase)
 108 {
 109     ValueRecovery argumentCountRecovery;
 110     VirtualRegister firstArgumentReg;
 111     if (inlineCallFrame) {
 112         if (inlineCallFrame->isVarargs()) {
 113             argumentCountRecovery = ValueRecovery::displacedInJSStack(
 114                 inlineCallFrame->argumentCountRegister, DataFormatInt32);
 115         } else {
 116             argumentCountRecovery = ValueRecovery::constant(
 117                 jsNumber(inlineCallFrame->arguments.size()));
 118         }
 119         if (inlineCallFrame->arguments.size() > 1)
 120             firstArgumentReg = inlineCallFrame->arguments[1].virtualRegister();
 121         else
 122             firstArgumentReg = VirtualRegister(0);
 123     } else {
 124         argumentCountRecovery = ValueRecovery::displacedInJSStack(
 125             VirtualRegister(JSStack::ArgumentCount), DataFormatInt32);
 126         firstArgumentReg = VirtualRegister(CallFrame::argumentOffset(0));
 127     }
 128     emitSetupVarargsFrameFastCase(jit, numUsedSlotsGPR, scratchGPR1, scratchGPR2, scratchGPR3, argumentCountRecovery, firstArgumentReg, firstVarArgOffset, slowCase);
 129 }
 130
 131 } // namespace JSC
 132
 133 #endif // ENABLE(JIT)
 134