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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
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* vim: set ts=4 sw=4 et tw=99:
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#include "TrampolineCompiler.h"
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#include "assembler/assembler/LinkBuffer.h"
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#include "assembler/jit/ExecutableAllocator.h"
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#define CHECK_RESULT(x) if (!(x)) return false
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#define COMPILE(which, pool, how) CHECK_RESULT(compileTrampoline(&(which), &pool, how))
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#define RELEASE(which, pool) JS_BEGIN_MACRO \
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typedef JSC::MacroAssembler::Address Address;
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typedef JSC::MacroAssembler::Label Label;
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typedef JSC::MacroAssembler::Jump Jump;
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typedef JSC::MacroAssembler::ImmPtr ImmPtr;
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typedef JSC::MacroAssembler::Imm32 Imm32;
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typedef JSC::MacroAssembler::Address Address;
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TrampolineCompiler::compile()
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#ifdef JS_METHODJIT_SPEW
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COMPILE(trampolines->forceReturn, trampolines->forceReturnPool, generateForceReturn);
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#if (defined(JS_NO_FASTCALL) && defined(JS_CPU_X86)) || defined(_WIN64)
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COMPILE(trampolines->forceReturnFast, trampolines->forceReturnFastPool, generateForceReturnFast);
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TrampolineCompiler::release(Trampolines *tramps)
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RELEASE(tramps->forceReturn, tramps->forceReturnPool);
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#if (defined(JS_NO_FASTCALL) && defined(JS_CPU_X86)) || defined(_WIN64)
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RELEASE(tramps->forceReturnFast, tramps->forceReturnFastPool);
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TrampolineCompiler::compileTrampoline(Trampolines::TrampolinePtr *where,
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JSC::ExecutablePool **poolp, TrampolineGenerator generator)
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Label entry = masm.label();
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CHECK_RESULT(generator(masm));
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JS_ASSERT(entry.isSet());
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JSC::LinkBuffer buffer(&masm, execAlloc, poolp, &ok, JSC::METHOD_CODE);
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masm.finalize(buffer);
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uint8_t *result = (uint8_t*)buffer.finalizeCodeAddendum().dataLocation();
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*where = JS_DATA_TO_FUNC_PTR(Trampolines::TrampolinePtr, result + masm.distanceOf(entry));
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* This is shamelessly copied from emitReturn, but with several changes:
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* - There was always at least one inline call.
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* - We don't know if there are activation objects or a script with nesting
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* state whose active frames need adjustment, so we always stub the epilogue.
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* - We don't know where we came from, so we don't know frame depth or PC.
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* - There is no stub buffer.
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TrampolineCompiler::generateForceReturn(Assembler &masm)
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/* The JSStackFrame register may have been clobbered while returning, reload it. */
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masm.loadPtr(FrameAddress(VMFrame::offsetOfFp), JSFrameReg);
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/* Perform the frame epilogue. */
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masm.fallibleVMCall(true, JS_FUNC_TO_DATA_PTR(void *, stubs::AnyFrameEpilogue), NULL, NULL, 0);
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/* Store any known return value */
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masm.loadValueAsComponents(UndefinedValue(), JSReturnReg_Type, JSReturnReg_Data);
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Jump rvalClear = masm.branchTest32(Assembler::Zero,
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FrameFlagsAddress(), Imm32(StackFrame::HAS_RVAL));
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Address rvalAddress(JSFrameReg, StackFrame::offsetOfReturnValue());
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masm.loadValueAsComponents(rvalAddress, JSReturnReg_Type, JSReturnReg_Data);
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rvalClear.linkTo(masm.label(), &masm);
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/* Return to the caller */
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masm.loadPtr(Address(JSFrameReg, StackFrame::offsetOfNcode()), Registers::ReturnReg);
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masm.jump(Registers::ReturnReg);
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#if (defined(JS_NO_FASTCALL) && defined(JS_CPU_X86)) || defined(_WIN64)
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TrampolineCompiler::generateForceReturnFast(Assembler &masm)
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masm.addPtr(Imm32(32), Registers::StackPointer);
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// In case of no fast call, when we change the return address,
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// we need to make sure add esp by 8.
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masm.addPtr(Imm32(16), Registers::StackPointer);
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return generateForceReturn(masm);
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} /* namespace mjit */