Source/JavaScriptCore/ftl/FTLThunks.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2013-2019 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "config.h"
 #include "FTLThunks.h"

 #if ENABLE(FTL_JIT)

 #include "AssemblyHelpers.h"
 #include "DFGOSRExitCompilerCommon.h"
 #include "FTLOSRExitCompiler.h"
 #include "FTLOperations.h"
 #include "FTLSaveRestore.h"
 #include "GPRInfo.h"
 #include "LinkBuffer.h"

 namespace JSC { namespace FTL {

 using namespace DFG;

 enum class FrameAndStackAdjustmentRequirement {
     Needed,
     NotNeeded
 };

 static MacroAssemblerCodeRef<JITThunkPtrTag> genericGenerationThunkGenerator(
     VM& vm, FunctionPtr<CFunctionPtrTag> generationFunction, PtrTag resultTag, const char* name, unsigned extraPopsToRestore, FrameAndStackAdjustmentRequirement frameAndStackAdjustmentRequirement)
 {
     AssemblyHelpers jit(nullptr);

     if (frameAndStackAdjustmentRequirement == FrameAndStackAdjustmentRequirement::Needed) {
         // This needs to happen before we use the scratch buffer because this function also uses the scratch buffer.
         adjustFrameAndStackInOSRExitCompilerThunk<FTL::JITCode>(jit, vm, JITType::FTLJIT);
     }

     // Note that the "return address" will be the ID that we pass to the generation function.

     ptrdiff_t stackMisalignment = MacroAssembler::pushToSaveByteOffset();

     // Pretend that we're a C call frame.
     jit.pushToSave(MacroAssembler::framePointerRegister);
     jit.move(MacroAssembler::stackPointerRegister, MacroAssembler::framePointerRegister);
     stackMisalignment += MacroAssembler::pushToSaveByteOffset();

     // Now create ourselves enough stack space to give saveAllRegisters() a scratch slot.
     unsigned numberOfRequiredPops = 0;
     do {
         jit.pushToSave(GPRInfo::regT0);
         stackMisalignment += MacroAssembler::pushToSaveByteOffset();
         numberOfRequiredPops++;
     } while (stackMisalignment % stackAlignmentBytes());

     ScratchBuffer* scratchBuffer = vm.scratchBufferForSize(requiredScratchMemorySizeInBytes());
     char* buffer = static_cast<char*>(scratchBuffer->dataBuffer());

     saveAllRegisters(jit, buffer);

     // Tell GC mark phase how much of the scratch buffer is active during call.
     jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->addressOfActiveLength()), GPRInfo::nonArgGPR0);
     jit.storePtr(MacroAssembler::TrustedImmPtr(requiredScratchMemorySizeInBytes()), GPRInfo::nonArgGPR0);

     jit.loadPtr(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
     jit.peek(
         GPRInfo::argumentGPR1,
         (stackMisalignment - MacroAssembler::pushToSaveByteOffset()) / sizeof(void*));
     jit.prepareCallOperation(vm);
     MacroAssembler::Call functionCall = jit.call(OperationPtrTag);

     // At this point we want to make a tail call to what was returned to us in the
     // returnValueGPR. But at the same time as we do this, we must restore all registers.
     // The way we will accomplish this is by arranging to have the tail call target in the
     // return address "slot" (be it a register or the stack).

     jit.move(GPRInfo::returnValueGPR, GPRInfo::regT0);

     // Make sure we tell the GC that we're not using the scratch buffer anymore.
     jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->addressOfActiveLength()), GPRInfo::regT1);
     jit.storePtr(MacroAssembler::TrustedImmPtr(nullptr), GPRInfo::regT1);

     // Prepare for tail call.
     while (numberOfRequiredPops--)
         jit.popToRestore(GPRInfo::regT1);
     jit.popToRestore(MacroAssembler::framePointerRegister);

     // When we came in here, there was an additional thing pushed to the stack. Some clients want it
     // popped before proceeding.
     while (extraPopsToRestore--)
         jit.popToRestore(GPRInfo::regT1);

     // Put the return address wherever the return instruction wants it. On all platforms, this
     // ensures that the return address is out of the way of register restoration.
     jit.restoreReturnAddressBeforeReturn(GPRInfo::regT0);

     restoreAllRegisters(jit, buffer);

 #if CPU(ARM64E)
     jit.untagPtr(resultTag, AssemblyHelpers::linkRegister);
     jit.tagReturnAddress();
 #else
     UNUSED_PARAM(resultTag);
 #endif
     jit.ret();

     LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID);
     patchBuffer.link(functionCall, generationFunction.retagged<OperationPtrTag>());
     return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "%s", name);
 }

 MacroAssemblerCodeRef<JITThunkPtrTag> osrExitGenerationThunkGenerator(VM& vm)
 {
     unsigned extraPopsToRestore = 0;
     return genericGenerationThunkGenerator(
         vm, operationCompileFTLOSRExit, OSRExitPtrTag, "FTL OSR exit generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::Needed);
 }

 MacroAssemblerCodeRef<JITThunkPtrTag> lazySlowPathGenerationThunkGenerator(VM& vm)
 {
     unsigned extraPopsToRestore = 1;
     return genericGenerationThunkGenerator(
         vm, operationCompileFTLLazySlowPath, JITStubRoutinePtrTag, "FTL lazy slow path generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::NotNeeded);
 }

 static void registerClobberCheck(AssemblyHelpers& jit, RegisterSet dontClobber)
 {
     if (!Options::clobberAllRegsInFTLICSlowPath())
         return;

     RegisterSet clobber = RegisterSet::allRegisters();
     clobber.exclude(RegisterSet::reservedHardwareRegisters());
     clobber.exclude(RegisterSet::stackRegisters());
     clobber.exclude(RegisterSet::calleeSaveRegisters());
     clobber.exclude(dontClobber);

     GPRReg someGPR = InvalidGPRReg;
     for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
         if (!clobber.get(reg) || !reg.isGPR())
             continue;

         jit.move(AssemblyHelpers::TrustedImm32(0x1337beef), reg.gpr());
         someGPR = reg.gpr();
     }

     for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
         if (!clobber.get(reg) || !reg.isFPR())
             continue;

         jit.move64ToDouble(someGPR, reg.fpr());
     }
 }

 MacroAssemblerCodeRef<JITThunkPtrTag> slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey& key)
 {
     AssemblyHelpers jit(nullptr);
     jit.tagReturnAddress();

     // We want to save the given registers at the given offset, then we want to save the
     // old return address somewhere past that offset, and then finally we want to make the
     // call.

     size_t currentOffset = key.offset() + sizeof(void*);

 #if CPU(X86_64)
     currentOffset += sizeof(void*);
 #endif

     for (MacroAssembler::RegisterID reg = MacroAssembler::firstRegister(); reg <= MacroAssembler::lastRegister(); reg = static_cast<MacroAssembler::RegisterID>(reg + 1)) {
         if (!key.usedRegisters().get(reg))
             continue;
         jit.storePtr(reg, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset));
         currentOffset += sizeof(void*);
     }

     for (MacroAssembler::FPRegisterID reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = static_cast<MacroAssembler::FPRegisterID>(reg + 1)) {
         if (!key.usedRegisters().get(reg))
             continue;
         jit.storeDouble(reg, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset));
         currentOffset += sizeof(double);
     }

     jit.preserveReturnAddressAfterCall(GPRInfo::nonArgGPR0);
     jit.storePtr(GPRInfo::nonArgGPR0, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()));
     jit.prepareCallOperation(vm);

     registerClobberCheck(jit, key.argumentRegisters());

     AssemblyHelpers::Call call = jit.call(OperationPtrTag);

     jit.loadPtr(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()), GPRInfo::nonPreservedNonReturnGPR);
     jit.restoreReturnAddressBeforeReturn(GPRInfo::nonPreservedNonReturnGPR);

     for (MacroAssembler::FPRegisterID reg = MacroAssembler::lastFPRegister(); ; reg = static_cast<MacroAssembler::FPRegisterID>(reg - 1)) {
         if (key.usedRegisters().get(reg)) {
             currentOffset -= sizeof(double);
             jit.loadDouble(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset), reg);
         }
         if (reg == MacroAssembler::firstFPRegister())
             break;
     }

     for (MacroAssembler::RegisterID reg = MacroAssembler::lastRegister(); ; reg = static_cast<MacroAssembler::RegisterID>(reg - 1)) {
         if (key.usedRegisters().get(reg)) {
             currentOffset -= sizeof(void*);
             jit.loadPtr(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset), reg);
         }
         if (reg == MacroAssembler::firstRegister())
             break;
     }

     jit.ret();

     LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID);
     patchBuffer.link(call, key.callTarget());
     return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "FTL slow path call thunk for %s", toCString(key).data());
 }

 } } // namespace JSC::FTL

 #endif // ENABLE(FTL_JIT)
	/*
	* Copyright (C) 2013-2019 Apple Inc. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
	* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
	* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
	* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
	* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "config.h"
	#include "FTLThunks.h"

	#if ENABLE(FTL_JIT)

	#include "AssemblyHelpers.h"
	#include "DFGOSRExitCompilerCommon.h"
	#include "FTLOSRExitCompiler.h"
	#include "FTLOperations.h"
	#include "FTLSaveRestore.h"
	#include "GPRInfo.h"
	#include "LinkBuffer.h"

	namespace JSC { namespace FTL {

	using namespace DFG;

	enum class FrameAndStackAdjustmentRequirement {
	Needed,
	NotNeeded
	};

	static MacroAssemblerCodeRef<JITThunkPtrTag> genericGenerationThunkGenerator(
	VM& vm, FunctionPtr<CFunctionPtrTag> generationFunction, PtrTag resultTag, const char* name, unsigned extraPopsToRestore, FrameAndStackAdjustmentRequirement frameAndStackAdjustmentRequirement)
	{
	AssemblyHelpers jit(nullptr);

	if (frameAndStackAdjustmentRequirement == FrameAndStackAdjustmentRequirement::Needed) {
	// This needs to happen before we use the scratch buffer because this function also uses the scratch buffer.
	adjustFrameAndStackInOSRExitCompilerThunk<FTL::JITCode>(jit, vm, JITType::FTLJIT);
	}

	// Note that the "return address" will be the ID that we pass to the generation function.

	ptrdiff_t stackMisalignment = MacroAssembler::pushToSaveByteOffset();

	// Pretend that we're a C call frame.
	jit.pushToSave(MacroAssembler::framePointerRegister);
	jit.move(MacroAssembler::stackPointerRegister, MacroAssembler::framePointerRegister);
	stackMisalignment += MacroAssembler::pushToSaveByteOffset();

	// Now create ourselves enough stack space to give saveAllRegisters() a scratch slot.
	unsigned numberOfRequiredPops = 0;
	do {
	jit.pushToSave(GPRInfo::regT0);
	stackMisalignment += MacroAssembler::pushToSaveByteOffset();
	numberOfRequiredPops++;
	} while (stackMisalignment % stackAlignmentBytes());

	ScratchBuffer* scratchBuffer = vm.scratchBufferForSize(requiredScratchMemorySizeInBytes());
	char* buffer = static_cast<char*>(scratchBuffer->dataBuffer());

	saveAllRegisters(jit, buffer);

	// Tell GC mark phase how much of the scratch buffer is active during call.
	jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->addressOfActiveLength()), GPRInfo::nonArgGPR0);
	jit.storePtr(MacroAssembler::TrustedImmPtr(requiredScratchMemorySizeInBytes()), GPRInfo::nonArgGPR0);

	jit.loadPtr(GPRInfo::callFrameRegister, GPRInfo::argumentGPR0);
	jit.peek(
	GPRInfo::argumentGPR1,
	(stackMisalignment - MacroAssembler::pushToSaveByteOffset()) / sizeof(void*));
	jit.prepareCallOperation(vm);
	MacroAssembler::Call functionCall = jit.call(OperationPtrTag);

	// At this point we want to make a tail call to what was returned to us in the
	// returnValueGPR. But at the same time as we do this, we must restore all registers.
	// The way we will accomplish this is by arranging to have the tail call target in the
	// return address "slot" (be it a register or the stack).

	jit.move(GPRInfo::returnValueGPR, GPRInfo::regT0);

	// Make sure we tell the GC that we're not using the scratch buffer anymore.
	jit.move(MacroAssembler::TrustedImmPtr(scratchBuffer->addressOfActiveLength()), GPRInfo::regT1);
	jit.storePtr(MacroAssembler::TrustedImmPtr(nullptr), GPRInfo::regT1);

	// Prepare for tail call.
	while (numberOfRequiredPops--)
	jit.popToRestore(GPRInfo::regT1);
	jit.popToRestore(MacroAssembler::framePointerRegister);

	// When we came in here, there was an additional thing pushed to the stack. Some clients want it
	// popped before proceeding.
	while (extraPopsToRestore--)
	jit.popToRestore(GPRInfo::regT1);

	// Put the return address wherever the return instruction wants it. On all platforms, this
	// ensures that the return address is out of the way of register restoration.
	jit.restoreReturnAddressBeforeReturn(GPRInfo::regT0);

	restoreAllRegisters(jit, buffer);

	#if CPU(ARM64E)
	jit.untagPtr(resultTag, AssemblyHelpers::linkRegister);
	jit.tagReturnAddress();
	#else
	UNUSED_PARAM(resultTag);
	#endif
	jit.ret();

	LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID);
	patchBuffer.link(functionCall, generationFunction.retagged<OperationPtrTag>());
	return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "%s", name);
	}

	MacroAssemblerCodeRef<JITThunkPtrTag> osrExitGenerationThunkGenerator(VM& vm)
	{
	unsigned extraPopsToRestore = 0;
	return genericGenerationThunkGenerator(
	vm, operationCompileFTLOSRExit, OSRExitPtrTag, "FTL OSR exit generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::Needed);
	}

	MacroAssemblerCodeRef<JITThunkPtrTag> lazySlowPathGenerationThunkGenerator(VM& vm)
	{
	unsigned extraPopsToRestore = 1;
	return genericGenerationThunkGenerator(
	vm, operationCompileFTLLazySlowPath, JITStubRoutinePtrTag, "FTL lazy slow path generation thunk", extraPopsToRestore, FrameAndStackAdjustmentRequirement::NotNeeded);
	}

	static void registerClobberCheck(AssemblyHelpers& jit, RegisterSet dontClobber)
	{
	if (!Options::clobberAllRegsInFTLICSlowPath())
	return;

	RegisterSet clobber = RegisterSet::allRegisters();
	clobber.exclude(RegisterSet::reservedHardwareRegisters());
	clobber.exclude(RegisterSet::stackRegisters());
	clobber.exclude(RegisterSet::calleeSaveRegisters());
	clobber.exclude(dontClobber);

	GPRReg someGPR = InvalidGPRReg;
	for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
	if (!clobber.get(reg) \|\| !reg.isGPR())
	continue;

	jit.move(AssemblyHelpers::TrustedImm32(0x1337beef), reg.gpr());
	someGPR = reg.gpr();
	}

	for (Reg reg = Reg::first(); reg <= Reg::last(); reg = reg.next()) {
	if (!clobber.get(reg) \|\| !reg.isFPR())
	continue;

	jit.move64ToDouble(someGPR, reg.fpr());
	}
	}

	MacroAssemblerCodeRef<JITThunkPtrTag> slowPathCallThunkGenerator(VM& vm, const SlowPathCallKey& key)
	{
	AssemblyHelpers jit(nullptr);
	jit.tagReturnAddress();

	// We want to save the given registers at the given offset, then we want to save the
	// old return address somewhere past that offset, and then finally we want to make the
	// call.

	size_t currentOffset = key.offset() + sizeof(void*);

	#if CPU(X86_64)
	currentOffset += sizeof(void*);
	#endif

	for (MacroAssembler::RegisterID reg = MacroAssembler::firstRegister(); reg <= MacroAssembler::lastRegister(); reg = static_cast<MacroAssembler::RegisterID>(reg + 1)) {
	if (!key.usedRegisters().get(reg))
	continue;
	jit.storePtr(reg, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset));
	currentOffset += sizeof(void*);
	}

	for (MacroAssembler::FPRegisterID reg = MacroAssembler::firstFPRegister(); reg <= MacroAssembler::lastFPRegister(); reg = static_cast<MacroAssembler::FPRegisterID>(reg + 1)) {
	if (!key.usedRegisters().get(reg))
	continue;
	jit.storeDouble(reg, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset));
	currentOffset += sizeof(double);
	}

	jit.preserveReturnAddressAfterCall(GPRInfo::nonArgGPR0);
	jit.storePtr(GPRInfo::nonArgGPR0, AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()));
	jit.prepareCallOperation(vm);

	registerClobberCheck(jit, key.argumentRegisters());

	AssemblyHelpers::Call call = jit.call(OperationPtrTag);

	jit.loadPtr(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, key.offset()), GPRInfo::nonPreservedNonReturnGPR);
	jit.restoreReturnAddressBeforeReturn(GPRInfo::nonPreservedNonReturnGPR);

	for (MacroAssembler::FPRegisterID reg = MacroAssembler::lastFPRegister(); ; reg = static_cast<MacroAssembler::FPRegisterID>(reg - 1)) {
	if (key.usedRegisters().get(reg)) {
	currentOffset -= sizeof(double);
	jit.loadDouble(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset), reg);
	}
	if (reg == MacroAssembler::firstFPRegister())
	break;
	}

	for (MacroAssembler::RegisterID reg = MacroAssembler::lastRegister(); ; reg = static_cast<MacroAssembler::RegisterID>(reg - 1)) {
	if (key.usedRegisters().get(reg)) {
	currentOffset -= sizeof(void*);
	jit.loadPtr(AssemblyHelpers::Address(MacroAssembler::stackPointerRegister, currentOffset), reg);
	}
	if (reg == MacroAssembler::firstRegister())
	break;
	}

	jit.ret();

	LinkBuffer patchBuffer(jit, GLOBAL_THUNK_ID);
	patchBuffer.link(call, key.callTarget());
	return FINALIZE_CODE(patchBuffer, JITThunkPtrTag, "FTL slow path call thunk for %s", toCString(key).data());
	}

	} } // namespace JSC::FTL

	#endif // ENABLE(FTL_JIT)