Source/JavaScriptCore/b3/air/AirGenerate.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2015-2017 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 "AirGenerate.h"

 #if ENABLE(B3_JIT)

 #include "AirAllocateRegistersAndStackAndGenerateCode.h"
 #include "AirAllocateRegistersAndStackByLinearScan.h"
 #include "AirAllocateRegistersByGraphColoring.h"
 #include "AirAllocateStackByGraphColoring.h"
 #include "AirCode.h"
 #include "AirEliminateDeadCode.h"
 #include "AirFixObviousSpills.h"
 #include "AirFixPartialRegisterStalls.h"
 #include "AirGenerationContext.h"
 #include "AirHandleCalleeSaves.h"
 #include "AirLiveness.h"
 #include "AirLogRegisterPressure.h"
 #include "AirLowerAfterRegAlloc.h"
 #include "AirLowerEntrySwitch.h"
 #include "AirLowerMacros.h"
 #include "AirLowerStackArgs.h"
 #include "AirOpcodeUtils.h"
 #include "AirOptimizeBlockOrder.h"
 #include "AirReportUsedRegisters.h"
 #include "AirSimplifyCFG.h"
 #include "AirStackAllocation.h"
 #include "AirTmpMap.h"
 #include "AirValidate.h"
 #include "B3Common.h"
 #include "B3Procedure.h"
 #include "B3TimingScope.h"
 #include "B3ValueInlines.h"
 #include "CCallHelpers.h"
 #include "DisallowMacroScratchRegisterUsage.h"
 #include "LinkBuffer.h"
 #include <wtf/IndexMap.h>

 namespace JSC { namespace B3 { namespace Air {

 void prepareForGeneration(Code& code)
 {
     TimingScope timingScope("Air::prepareForGeneration");

     // If we're doing super verbose dumping, the phase scope of any phase will already do a dump.
     if (shouldDumpIR(AirMode) && !shouldDumpIRAtEachPhase(AirMode)) {
         dataLog("Initial air:\n");
         dataLog(code);
     }

     // We don't expect the incoming code to have predecessors computed.
     code.resetReachability();

     if (shouldValidateIR())
         validate(code);

     if (!code.optLevel()) {
         lowerMacros(code);

         // FIXME: The name of this phase doesn't make much sense in O0 since we do this before
         // register allocation.
         lowerAfterRegAlloc(code);

         // Actually create entrypoints.
         lowerEntrySwitch(code);

         // This sorts the basic blocks in Code to achieve an ordering that maximizes the likelihood that a high
         // frequency successor is also the fall-through target.
         optimizeBlockOrder(code);

         if (shouldValidateIR())
             validate(code);

         if (shouldDumpIR(AirMode)) {
             dataLog("Air after ", code.lastPhaseName(), ", before generation:\n");
             dataLog(code);
         }

         code.m_generateAndAllocateRegisters = makeUnique<GenerateAndAllocateRegisters>(code);
         code.m_generateAndAllocateRegisters->prepareForGeneration();

         return;
     }

     simplifyCFG(code);

     lowerMacros(code);

     // This is where we run our optimizations and transformations.
     // FIXME: Add Air optimizations.
     // https://bugs.webkit.org/show_bug.cgi?id=150456

     eliminateDeadCode(code);

     if (code.optLevel() == 1) {
         // When we're compiling quickly, we do register and stack allocation in one linear scan
         // phase. It's fast because it computes liveness only once.
         allocateRegistersAndStackByLinearScan(code);

         if (Options::logAirRegisterPressure()) {
             dataLog("Register pressure after register allocation:\n");
             logRegisterPressure(code);
         }

         // We may still need to do post-allocation lowering. Doing it after both register and
         // stack allocation is less optimal, but it works fine.
         lowerAfterRegAlloc(code);
     } else {
         // NOTE: B3 -O2 generates code that runs 1.5x-2x faster than code generated by -O1.
         // Most of this performance benefit is from -O2's graph coloring register allocation
         // and stack allocation pipeline, which you see below.

         // Register allocation for all the Tmps that do not have a corresponding machine
         // register. After this phase, every Tmp has a reg.
         allocateRegistersByGraphColoring(code);

         if (Options::logAirRegisterPressure()) {
             dataLog("Register pressure after register allocation:\n");
             logRegisterPressure(code);
         }

         // This replaces uses of spill slots with registers or constants if possible. It
         // does this by minimizing the amount that we perturb the already-chosen register
         // allocation. It may extend the live ranges of registers though.
         fixObviousSpills(code);

         lowerAfterRegAlloc(code);

         // This does first-fit allocation of stack slots using an interference graph plus a
         // bunch of other optimizations.
         allocateStackByGraphColoring(code);
     }

     // This turns all Stack and CallArg Args into Addr args that use the frame pointer.
     lowerStackArgs(code);

     // If we coalesced moves then we can unbreak critical edges. This is the main reason for this
     // phase.
     simplifyCFG(code);

     // This is needed to satisfy a requirement of B3::StackmapValue. This also removes dead
     // code. We can avoid running this when certain optimizations are disabled.
     if (code.optLevel() >= 2 || code.needsUsedRegisters())
         reportUsedRegisters(code);

     // Attempt to remove false dependencies between instructions created by partial register changes.
     // This must be executed as late as possible as it depends on the instructions order and register
     // use. We _must_ run this after reportUsedRegisters(), since that kills variable assignments
     // that seem dead. Luckily, this phase does not change register liveness, so that's OK.
     fixPartialRegisterStalls(code);

     // Actually create entrypoints.
     lowerEntrySwitch(code);

     // The control flow graph can be simplified further after we have lowered EntrySwitch.
     simplifyCFG(code);

     // This sorts the basic blocks in Code to achieve an ordering that maximizes the likelihood that a high
     // frequency successor is also the fall-through target.
     optimizeBlockOrder(code);

     if (shouldValidateIR())
         validate(code);

     // Do a final dump of Air. Note that we have to do this even if we are doing per-phase dumping,
     // since the final generation is not a phase.
     if (shouldDumpIR(AirMode)) {
         dataLog("Air after ", code.lastPhaseName(), ", before generation:\n");
         dataLog(code);
     }
 }

 static void generateWithAlreadyAllocatedRegisters(Code& code, CCallHelpers& jit)
 {
     TimingScope timingScope("Air::generate");

     DisallowMacroScratchRegisterUsage disallowScratch(jit);

     // And now, we generate code.
     GenerationContext context;
     context.code = &code;
     context.blockLabels.resize(code.size());
     for (BasicBlock* block : code)
         context.blockLabels[block] = Box<CCallHelpers::Label>::create();
     IndexMap<BasicBlock*, CCallHelpers::JumpList> blockJumps(code.size());

     auto link = [&] (CCallHelpers::Jump jump, BasicBlock* target) {
         if (context.blockLabels[target]->isSet()) {
             jump.linkTo(*context.blockLabels[target], &jit);
             return;
         }

         blockJumps[target].append(jump);
     };

     PCToOriginMap& pcToOriginMap = code.proc().pcToOriginMap();
     auto addItem = [&] (Inst& inst) {
         if (!inst.origin) {
             pcToOriginMap.appendItem(jit.labelIgnoringWatchpoints(), Origin());
             return;
         }
         pcToOriginMap.appendItem(jit.labelIgnoringWatchpoints(), inst.origin->origin());
     };

     Disassembler* disassembler = code.disassembler();

     for (BasicBlock* block : code) {
         context.currentBlock = block;
         context.indexInBlock = UINT_MAX;
         blockJumps[block].link(&jit);
         CCallHelpers::Label label = jit.label();
         *context.blockLabels[block] = label;

         if (disassembler)
             disassembler->startBlock(block, jit);

         if (Optional<unsigned> entrypointIndex = code.entrypointIndex(block)) {
             ASSERT(code.isEntrypoint(block));

             if (disassembler)
                 disassembler->startEntrypoint(jit);

             code.prologueGeneratorForEntrypoint(*entrypointIndex)->run(jit, code);

             if (disassembler)
                 disassembler->endEntrypoint(jit);
         } else
             ASSERT(!code.isEntrypoint(block));

         ASSERT(block->size() >= 1);
         for (unsigned i = 0; i < block->size() - 1; ++i) {
             context.indexInBlock = i;
             Inst& inst = block->at(i);
             addItem(inst);
             auto start = jit.labelIgnoringWatchpoints();
             CCallHelpers::Jump jump = inst.generate(jit, context);
             ASSERT_UNUSED(jump, !jump.isSet());
             auto end = jit.labelIgnoringWatchpoints();
             if (disassembler)
                 disassembler->addInst(&inst, start, end);
         }

         context.indexInBlock = block->size() - 1;

         if (block->last().kind.opcode == Jump
             && block->successorBlock(0) == code.findNextBlock(block))
             continue;

         addItem(block->last());

         if (isReturn(block->last().kind.opcode)) {
             // We currently don't represent the full prologue/epilogue in Air, so we need to
             // have this override.
             auto start = jit.labelIgnoringWatchpoints();
             if (code.frameSize()) {
                 jit.emitRestore(code.calleeSaveRegisterAtOffsetList());
                 jit.emitFunctionEpilogue();
             } else
                 jit.emitFunctionEpilogueWithEmptyFrame();
             jit.ret();
             addItem(block->last());
             auto end = jit.labelIgnoringWatchpoints();
             if (disassembler)
                 disassembler->addInst(&block->last(), start, end);
             continue;
         }

         auto start = jit.labelIgnoringWatchpoints();
         CCallHelpers::Jump jump = block->last().generate(jit, context);
         auto end = jit.labelIgnoringWatchpoints();
         if (disassembler)
             disassembler->addInst(&block->last(), start, end);

         // The jump won't be set for patchpoints. It won't be set for Oops because then it won't have
         // any successors.
         if (jump.isSet()) {
             switch (block->numSuccessors()) {
             case 1:
                 link(jump, block->successorBlock(0));
                 break;
             case 2:
                 link(jump, block->successorBlock(0));
                 if (block->successorBlock(1) != code.findNextBlock(block))
                     link(jit.jump(), block->successorBlock(1));
                 break;
             default:
                 RELEASE_ASSERT_NOT_REACHED();
                 break;
             }
         }
         addItem(block->last());
     }

     context.currentBlock = nullptr;
     context.indexInBlock = UINT_MAX;

     Vector<CCallHelpers::Label> entrypointLabels(code.numEntrypoints());
     for (unsigned i = code.numEntrypoints(); i--;)
         entrypointLabels[i] = *context.blockLabels[code.entrypoint(i).block()];
     code.setEntrypointLabels(WTFMove(entrypointLabels));

     pcToOriginMap.appendItem(jit.label(), Origin());
     // FIXME: Make late paths have Origins: https://bugs.webkit.org/show_bug.cgi?id=153689
     if (disassembler)
         disassembler->startLatePath(jit);

     for (auto& latePath : context.latePaths)
         latePath->run(jit, context);

     if (disassembler)
         disassembler->endLatePath(jit);
     pcToOriginMap.appendItem(jit.labelIgnoringWatchpoints(), Origin());
 }

 void generate(Code& code, CCallHelpers& jit)
 {
     if (code.optLevel())
         generateWithAlreadyAllocatedRegisters(code, jit);
     else
         code.m_generateAndAllocateRegisters->generate(jit);
 }

 } } } // namespace JSC::B3::Air

 #endif // ENABLE(B3_JIT)
	/*
	* Copyright (C) 2015-2017 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 "AirGenerate.h"

	#if ENABLE(B3_JIT)

	#include "AirAllocateRegistersAndStackAndGenerateCode.h"
	#include "AirAllocateRegistersAndStackByLinearScan.h"
	#include "AirAllocateRegistersByGraphColoring.h"
	#include "AirAllocateStackByGraphColoring.h"
	#include "AirCode.h"
	#include "AirEliminateDeadCode.h"
	#include "AirFixObviousSpills.h"
	#include "AirFixPartialRegisterStalls.h"
	#include "AirGenerationContext.h"
	#include "AirHandleCalleeSaves.h"
	#include "AirLiveness.h"
	#include "AirLogRegisterPressure.h"
	#include "AirLowerAfterRegAlloc.h"
	#include "AirLowerEntrySwitch.h"
	#include "AirLowerMacros.h"
	#include "AirLowerStackArgs.h"
	#include "AirOpcodeUtils.h"
	#include "AirOptimizeBlockOrder.h"
	#include "AirReportUsedRegisters.h"
	#include "AirSimplifyCFG.h"
	#include "AirStackAllocation.h"
	#include "AirTmpMap.h"
	#include "AirValidate.h"
	#include "B3Common.h"
	#include "B3Procedure.h"
	#include "B3TimingScope.h"
	#include "B3ValueInlines.h"
	#include "CCallHelpers.h"
	#include "DisallowMacroScratchRegisterUsage.h"
	#include "LinkBuffer.h"
	#include <wtf/IndexMap.h>

	namespace JSC { namespace B3 { namespace Air {

	void prepareForGeneration(Code& code)
	{
	TimingScope timingScope("Air::prepareForGeneration");

	// If we're doing super verbose dumping, the phase scope of any phase will already do a dump.
	if (shouldDumpIR(AirMode) && !shouldDumpIRAtEachPhase(AirMode)) {
	dataLog("Initial air:\n");
	dataLog(code);
	}

	// We don't expect the incoming code to have predecessors computed.
	code.resetReachability();

	if (shouldValidateIR())
	validate(code);

	if (!code.optLevel()) {
	lowerMacros(code);

	// FIXME: The name of this phase doesn't make much sense in O0 since we do this before
	// register allocation.
	lowerAfterRegAlloc(code);

	// Actually create entrypoints.
	lowerEntrySwitch(code);

	// This sorts the basic blocks in Code to achieve an ordering that maximizes the likelihood that a high
	// frequency successor is also the fall-through target.
	optimizeBlockOrder(code);

	if (shouldValidateIR())
	validate(code);

	if (shouldDumpIR(AirMode)) {
	dataLog("Air after ", code.lastPhaseName(), ", before generation:\n");
	dataLog(code);
	}

	code.m_generateAndAllocateRegisters = makeUnique<GenerateAndAllocateRegisters>(code);
	code.m_generateAndAllocateRegisters->prepareForGeneration();

	return;
	}

	simplifyCFG(code);

	lowerMacros(code);

	// This is where we run our optimizations and transformations.
	// FIXME: Add Air optimizations.
	// https://bugs.webkit.org/show_bug.cgi?id=150456

	eliminateDeadCode(code);

	if (code.optLevel() == 1) {
	// When we're compiling quickly, we do register and stack allocation in one linear scan
	// phase. It's fast because it computes liveness only once.
	allocateRegistersAndStackByLinearScan(code);

	if (Options::logAirRegisterPressure()) {
	dataLog("Register pressure after register allocation:\n");
	logRegisterPressure(code);
	}

	// We may still need to do post-allocation lowering. Doing it after both register and
	// stack allocation is less optimal, but it works fine.
	lowerAfterRegAlloc(code);
	} else {
	// NOTE: B3 -O2 generates code that runs 1.5x-2x faster than code generated by -O1.
	// Most of this performance benefit is from -O2's graph coloring register allocation
	// and stack allocation pipeline, which you see below.

	// Register allocation for all the Tmps that do not have a corresponding machine
	// register. After this phase, every Tmp has a reg.
	allocateRegistersByGraphColoring(code);

	if (Options::logAirRegisterPressure()) {
	dataLog("Register pressure after register allocation:\n");
	logRegisterPressure(code);
	}

	// This replaces uses of spill slots with registers or constants if possible. It
	// does this by minimizing the amount that we perturb the already-chosen register
	// allocation. It may extend the live ranges of registers though.
	fixObviousSpills(code);

	lowerAfterRegAlloc(code);

	// This does first-fit allocation of stack slots using an interference graph plus a
	// bunch of other optimizations.
	allocateStackByGraphColoring(code);
	}

	// This turns all Stack and CallArg Args into Addr args that use the frame pointer.
	lowerStackArgs(code);

	// If we coalesced moves then we can unbreak critical edges. This is the main reason for this
	// phase.
	simplifyCFG(code);

	// This is needed to satisfy a requirement of B3::StackmapValue. This also removes dead
	// code. We can avoid running this when certain optimizations are disabled.
	if (code.optLevel() >= 2 \|\| code.needsUsedRegisters())
	reportUsedRegisters(code);

	// Attempt to remove false dependencies between instructions created by partial register changes.
	// This must be executed as late as possible as it depends on the instructions order and register
	// use. We _must_ run this after reportUsedRegisters(), since that kills variable assignments
	// that seem dead. Luckily, this phase does not change register liveness, so that's OK.
	fixPartialRegisterStalls(code);

	// Actually create entrypoints.
	lowerEntrySwitch(code);

	// The control flow graph can be simplified further after we have lowered EntrySwitch.
	simplifyCFG(code);

	// This sorts the basic blocks in Code to achieve an ordering that maximizes the likelihood that a high
	// frequency successor is also the fall-through target.
	optimizeBlockOrder(code);

	if (shouldValidateIR())
	validate(code);

	// Do a final dump of Air. Note that we have to do this even if we are doing per-phase dumping,
	// since the final generation is not a phase.
	if (shouldDumpIR(AirMode)) {
	dataLog("Air after ", code.lastPhaseName(), ", before generation:\n");
	dataLog(code);
	}
	}

	static void generateWithAlreadyAllocatedRegisters(Code& code, CCallHelpers& jit)
	{
	TimingScope timingScope("Air::generate");

	DisallowMacroScratchRegisterUsage disallowScratch(jit);

	// And now, we generate code.
	GenerationContext context;
	context.code = &code;
	context.blockLabels.resize(code.size());
	for (BasicBlock* block : code)
	context.blockLabels[block] = Box<CCallHelpers::Label>::create();
	IndexMap<BasicBlock*, CCallHelpers::JumpList> blockJumps(code.size());

	auto link = [&] (CCallHelpers::Jump jump, BasicBlock* target) {
	if (context.blockLabels[target]->isSet()) {
	jump.linkTo(*context.blockLabels[target], &jit);
	return;
	}

	blockJumps[target].append(jump);
	};

	PCToOriginMap& pcToOriginMap = code.proc().pcToOriginMap();
	auto addItem = [&] (Inst& inst) {
	if (!inst.origin) {
	pcToOriginMap.appendItem(jit.labelIgnoringWatchpoints(), Origin());
	return;
	}
	pcToOriginMap.appendItem(jit.labelIgnoringWatchpoints(), inst.origin->origin());
	};

	Disassembler* disassembler = code.disassembler();

	for (BasicBlock* block : code) {
	context.currentBlock = block;
	context.indexInBlock = UINT_MAX;
	blockJumps[block].link(&jit);
	CCallHelpers::Label label = jit.label();
	*context.blockLabels[block] = label;

	if (disassembler)
	disassembler->startBlock(block, jit);

	if (Optional<unsigned> entrypointIndex = code.entrypointIndex(block)) {
	ASSERT(code.isEntrypoint(block));

	if (disassembler)
	disassembler->startEntrypoint(jit);

	code.prologueGeneratorForEntrypoint(*entrypointIndex)->run(jit, code);

	if (disassembler)
	disassembler->endEntrypoint(jit);
	} else
	ASSERT(!code.isEntrypoint(block));

	ASSERT(block->size() >= 1);
	for (unsigned i = 0; i < block->size() - 1; ++i) {
	context.indexInBlock = i;
	Inst& inst = block->at(i);
	addItem(inst);
	auto start = jit.labelIgnoringWatchpoints();
	CCallHelpers::Jump jump = inst.generate(jit, context);
	ASSERT_UNUSED(jump, !jump.isSet());
	auto end = jit.labelIgnoringWatchpoints();
	if (disassembler)
	disassembler->addInst(&inst, start, end);
	}

	context.indexInBlock = block->size() - 1;

	if (block->last().kind.opcode == Jump
	&& block->successorBlock(0) == code.findNextBlock(block))
	continue;

	addItem(block->last());

	if (isReturn(block->last().kind.opcode)) {
	// We currently don't represent the full prologue/epilogue in Air, so we need to
	// have this override.
	auto start = jit.labelIgnoringWatchpoints();
	if (code.frameSize()) {
	jit.emitRestore(code.calleeSaveRegisterAtOffsetList());
	jit.emitFunctionEpilogue();
	} else
	jit.emitFunctionEpilogueWithEmptyFrame();
	jit.ret();
	addItem(block->last());
	auto end = jit.labelIgnoringWatchpoints();
	if (disassembler)
	disassembler->addInst(&block->last(), start, end);
	continue;
	}

	auto start = jit.labelIgnoringWatchpoints();
	CCallHelpers::Jump jump = block->last().generate(jit, context);
	auto end = jit.labelIgnoringWatchpoints();
	if (disassembler)
	disassembler->addInst(&block->last(), start, end);

	// The jump won't be set for patchpoints. It won't be set for Oops because then it won't have
	// any successors.
	if (jump.isSet()) {
	switch (block->numSuccessors()) {
	case 1:
	link(jump, block->successorBlock(0));
	break;
	case 2:
	link(jump, block->successorBlock(0));
	if (block->successorBlock(1) != code.findNextBlock(block))
	link(jit.jump(), block->successorBlock(1));
	break;
	default:
	RELEASE_ASSERT_NOT_REACHED();
	break;
	}
	}
	addItem(block->last());
	}

	context.currentBlock = nullptr;
	context.indexInBlock = UINT_MAX;

	Vector<CCallHelpers::Label> entrypointLabels(code.numEntrypoints());
	for (unsigned i = code.numEntrypoints(); i--;)
	entrypointLabels[i] = *context.blockLabels[code.entrypoint(i).block()];
	code.setEntrypointLabels(WTFMove(entrypointLabels));

	pcToOriginMap.appendItem(jit.label(), Origin());
	// FIXME: Make late paths have Origins: https://bugs.webkit.org/show_bug.cgi?id=153689
	if (disassembler)
	disassembler->startLatePath(jit);

	for (auto& latePath : context.latePaths)
	latePath->run(jit, context);

	if (disassembler)
	disassembler->endLatePath(jit);
	pcToOriginMap.appendItem(jit.labelIgnoringWatchpoints(), Origin());
	}

	void generate(Code& code, CCallHelpers& jit)
	{
	if (code.optLevel())
	generateWithAlreadyAllocatedRegisters(code, jit);
	else
	code.m_generateAndAllocateRegisters->generate(jit);
	}

	} } } // namespace JSC::B3::Air

	#endif // ENABLE(B3_JIT)