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Diffstat (limited to 'backend/unittests/CodeGen/MachineOptimizationTest.cpp')
| -rw-r--r-- | backend/unittests/CodeGen/MachineOptimizationTest.cpp | 772 |
1 files changed, 772 insertions, 0 deletions
diff --git a/backend/unittests/CodeGen/MachineOptimizationTest.cpp b/backend/unittests/CodeGen/MachineOptimizationTest.cpp new file mode 100644 index 0000000..8d01a65 --- /dev/null +++ b/backend/unittests/CodeGen/MachineOptimizationTest.cpp @@ -0,0 +1,772 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#include "rcc/CodeGen/GenericOpcodes.h" +#include "rcc/CodeGen/MachineBasicBlock.h" +#include "rcc/CodeGen/MachineCFGUpdater.h" +#include "rcc/CodeGen/MachineCSE.h" +#include "rcc/CodeGen/MachineCombiner.h" +#include "rcc/CodeGen/MachineDCE.h" +#include "rcc/CodeGen/MachineFunction.h" +#include "rcc/CodeGen/MachineIRBuilder.h" +#include "rcc/CodeGen/MachineInstr.h" +#include "rcc/CodeGen/MachineLICM.h" +#include "rcc/CodeGen/MachineLiveness.h" +#include "rcc/CodeGen/MachineMemOperand.h" +#include "rcc/CodeGen/MachineMemoryFolding.h" +#include "rcc/CodeGen/MachineOperand.h" +#include "rcc/CodeGen/MachineRegisterInfo.h" +#include "rcc/CodeGen/MachineSink.h" +#include "rcc/CodeGen/TargetMemoryFolding.h" +#include "rcc/Target/RISCV/RISCVCodeGen.h" +#include "rcc/Target/RISCV/RISCVTarget.h" + +#include <cstdint> +#include <iostream> +#include <memory> +#include <optional> +#include <string> +#include <string_view> + +namespace { + +class TestContext final { +public: + void expect(bool Condition, std::string_view Message) { + if (Condition) + return; + std::cerr << Message << '\n'; + ++Failures; + } + + [[nodiscard]] int result() const noexcept { + return Failures == 0 ? 0 : 1; + } + +private: + int Failures = 0; +}; + +struct Fixture final { + std::unique_ptr<rcc::MachineFunction> Function; + rcc::MachineBasicBlock *Entry = nullptr; +}; + +[[nodiscard]] rcc::Opcode opcode(rcc::riscv::InstructionOpcode Value) noexcept; + +class TestMemoryFoldingInfo final : public rcc::TargetMemoryFoldingInfo { +public: + explicit TestMemoryFoldingInfo(bool DropMemory = false) noexcept : DropMemory(DropMemory) {} + + [[nodiscard]] rcc::Expected<bool> + canFoldMemoryOperand(const rcc::MachineInstr &Consumer, std::size_t OperandIndex, + const rcc::MachineInstr &MemoryInstruction, const rcc::MachineFunction &, + const rcc::TargetDescription &) const override { + return Consumer.opcode() == opcode(rcc::riscv::InstructionOpcode::ADDI) && OperandIndex == 1 && + MemoryInstruction.opcode() == opcode(rcc::riscv::InstructionOpcode::LD); + } + + [[nodiscard]] rcc::Expected<rcc::MachineInstr *> + foldMemoryOperand(rcc::MachineInstr &Consumer, std::size_t, rcc::MachineInstr &MemoryInstruction, + rcc::MachineFunction &Function, + const rcc::TargetDescription &Target) const override { + const rcc::MachineOperand *DestinationOperand = Consumer.operandAt(0); + const rcc::MachineOperand *BaseOperand = MemoryInstruction.operandAt(1); + const rcc::MachineOperand *OffsetOperand = MemoryInstruction.operandAt(2); + const rcc::Register *Destination = + DestinationOperand == nullptr ? nullptr : DestinationOperand->getIf<rcc::Register>(); + const rcc::Register *Base = + BaseOperand == nullptr ? nullptr : BaseOperand->getIf<rcc::Register>(); + const std::int64_t *Offset = + OffsetOperand == nullptr ? nullptr : OffsetOperand->getIf<std::int64_t>(); + rcc::MachineBasicBlock *Block = Consumer.parent(); + if (Destination == nullptr || Base == nullptr || Offset == nullptr || Block == nullptr || + MemoryInstruction.parent() != Block) { + return rcc::makeUnexpected(rcc::ErrorCode::VerificationError, + "test memory fold received an invalid candidate"); + } + + rcc::MachineIRBuilder Builder(Function, Target); + if (auto Point = Builder.setInsertPointBefore(Consumer); !Point) + return std::unexpected(Point.error()); + auto Pending = Builder.buildInstr(opcode(rcc::riscv::InstructionOpcode::LD)); + if (!Pending) + return std::unexpected(Pending.error()); + if (auto Added = Pending->addDef(*Destination); !Added) + return std::unexpected(Added.error()); + if (auto Added = Pending->addUse(*Base); !Added) + return std::unexpected(Added.error()); + if (auto Added = Pending->addImmediate(*Offset); !Added) + return std::unexpected(Added.error()); + for (const rcc::MachineMemOperand *Memory : MemoryInstruction.memOperands()) { + if (Memory == nullptr) + return rcc::makeUnexpected(rcc::ErrorCode::VerificationError, + "test memory fold received a null MMO"); + if (auto Added = Pending->addMemOperand(*Memory); !Added) + return std::unexpected(Added.error()); + } + auto Folded = Pending->build(); + if (!Folded) + return std::unexpected(Folded.error()); + if (DropMemory) { + while (!(*Folded)->memOperands().empty()) { + if (auto Erased = (*Folded)->eraseMemOperand(0); !Erased) + return std::unexpected(Erased.error()); + } + } + if (auto Removed = Block->removeInstruction(MemoryInstruction); !Removed) + return std::unexpected(Removed.error()); + if (auto Removed = Block->removeInstruction(Consumer); !Removed) + return std::unexpected(Removed.error()); + return *Folded; + } + + [[nodiscard]] rcc::Expected<bool> + unfoldMemoryOperand(rcc::MachineInstr &, rcc::MachineFunction &, + const rcc::TargetDescription &) const override { + return false; + } + + [[nodiscard]] rcc::Expected<std::optional<rcc::MemorySize>> + getFoldedMemorySize(const rcc::MachineInstr &, const rcc::MachineFunction &, + const rcc::TargetDescription &) const override { + auto Size = rcc::MemorySize::fixed(8); + if (!Size) + return std::unexpected(Size.error()); + return std::optional<rcc::MemorySize>(*Size); + } + +private: + bool DropMemory; +}; + +[[nodiscard]] rcc::Opcode opcode(rcc::riscv::InstructionOpcode Value) noexcept { + return rcc::Opcode::fromValue(static_cast<std::uint32_t>(Value)); +} + +[[nodiscard]] Fixture makeFixture(TestContext &Context, std::string Name, std::uint64_t ID) { + auto Function = + rcc::MachineFunction::create(std::move(Name), rcc::MachineFunctionStableID::fromValue(ID)); + Context.expect(Function.has_value(), "optimization fixture function creation must succeed"); + if (!Function) + return {}; + auto Entry = (*Function)->createBasicBlock(); + Context.expect(Entry.has_value(), "optimization fixture block creation must succeed"); + if (!Entry || !(*Function)->appendBlock(**Entry)) + return {}; + (*Function)->properties().set(rcc::MachineFunctionProperty::IsSSA); + (*Function)->properties().set(rcc::MachineFunctionProperty::Legalized); + (*Function)->properties().set(rcc::MachineFunctionProperty::RegBankSelected); + (*Function)->properties().set(rcc::MachineFunctionProperty::Selected); + return {std::move(*Function), *Entry}; +} + +void setPostRAProperties(rcc::MachineFunction &Function) { + Function.properties().clear(rcc::MachineFunctionProperty::IsSSA); + Function.properties().set(rcc::MachineFunctionProperty::NoPHIs); + Function.properties().set(rcc::MachineFunctionProperty::TiedOpsRewritten); + Function.properties().set(rcc::MachineFunctionProperty::NoVRegs); + Function.properties().set(rcc::MachineFunctionProperty::TracksLiveness); +} + +[[nodiscard]] rcc::Register makeGPR(TestContext &Context, rcc::MachineFunction &Function) { + auto Type = rcc::LLT::makeInteger(64); + auto Reg = Type ? Function.registerInfo().createVirtualRegister(*Type) + : rcc::Expected<rcc::Register>(std::unexpected( + rcc::Error(rcc::ErrorCode::InternalError, "test LLT creation failed"))); + Context.expect(Reg.has_value(), "optimization virtual register creation must succeed"); + if (!Reg) + return {}; + const auto Bank = + rcc::RegisterBankID::fromValue(static_cast<std::uint32_t>(rcc::riscv::RegisterBank::GPR)); + const auto Class = + rcc::RegisterClassID::fromValue(static_cast<std::uint32_t>(rcc::riscv::RegisterClass::GPR)); + Context.expect(Function.registerInfo().setRegisterBank(*Reg, Bank).has_value() && + Function.registerInfo().setRegisterClass(*Reg, Class).has_value(), + "optimization register constraints must be assigned"); + return *Reg; +} + +[[nodiscard]] rcc::PhysicalRegister physical(TestContext &Context, + rcc::riscv::PhysicalRegisterID ID) { + auto Reg = rcc::riscv::physicalRegister(ID); + Context.expect(Reg.has_value(), "optimization physical register lookup must succeed"); + return Reg.value_or(rcc::PhysicalRegister{}); +} + +[[nodiscard]] rcc::MachineInstr *buildADDI(TestContext &Context, rcc::MachineIRBuilder &Builder, + rcc::Register Destination, rcc::Register Source, + std::int64_t Immediate) { + auto Pending = Builder.buildInstr(opcode(rcc::riscv::InstructionOpcode::ADDI)); + if (!Pending || !Pending->addDef(Destination) || !Pending->addUse(Source) || + !Pending->addImmediate(Immediate)) { + Context.expect(false, "ADDI construction must succeed"); + return nullptr; + } + auto Built = Pending->build(); + Context.expect(Built.has_value(), "ADDI insertion must succeed"); + return Built.value_or(nullptr); +} + +[[nodiscard]] rcc::MachineInstr *buildADD(TestContext &Context, rcc::MachineIRBuilder &Builder, + rcc::Register Destination, rcc::Register Left, + rcc::Register Right) { + auto Pending = Builder.buildInstr(opcode(rcc::riscv::InstructionOpcode::ADD)); + if (!Pending || !Pending->addDef(Destination) || !Pending->addUse(Left) || + !Pending->addUse(Right)) { + Context.expect(false, "ADD construction must succeed"); + return nullptr; + } + auto Built = Pending->build(); + Context.expect(Built.has_value(), "ADD insertion must succeed"); + return Built.value_or(nullptr); +} + +[[nodiscard]] const rcc::MachineMemOperand * +makeMemory(TestContext &Context, rcc::MachineFunction &Function, bool Store, bool Invariant) { + auto Size = rcc::MemorySize::fixed(8); + auto Align = rcc::Alignment::create(8); + Context.expect(Size.has_value() && Align.has_value(), "memory shape creation must succeed"); + if (!Size || !Align) + return nullptr; + rcc::MemoryAccessFlags Flags{Store ? rcc::MemoryAccessFlag::Store : rcc::MemoryAccessFlag::Load}; + if (Invariant) { + Flags.set(rcc::MemoryAccessFlag::Invariant); + Flags.set(rcc::MemoryAccessFlag::Dereferenceable); + } + rcc::MachineMemOperandDesc Description; + Description.Accesses = Flags; + Description.Size = *Size; + Description.Align = *Align; + Description.Base = Invariant ? rcc::MemoryBase::constantPoolPseudo() : rcc::MemoryBase::stack(); + auto Memory = Function.createMemOperand(std::move(Description)); + Context.expect(Memory.has_value(), "memory operand creation must succeed"); + return Memory.value_or(nullptr); +} + +[[nodiscard]] rcc::MachineInstr *buildStore(TestContext &Context, rcc::MachineIRBuilder &Builder, + rcc::Register Value, rcc::PhysicalRegister StackPointer, + const rcc::MachineMemOperand &Memory) { + auto Pending = Builder.buildInstr(opcode(rcc::riscv::InstructionOpcode::SD)); + if (!Pending || !Pending->addUse(Value) || + !Pending->addUse(rcc::Register::fromPhysical(StackPointer)) || !Pending->addImmediate(0) || + !Pending->addMemOperand(Memory)) { + Context.expect(false, "store construction must succeed"); + return nullptr; + } + auto Built = Pending->build(); + Context.expect(Built.has_value(), "store insertion must succeed"); + return Built.value_or(nullptr); +} + +[[nodiscard]] rcc::MachineInstr *buildLoad(TestContext &Context, rcc::MachineIRBuilder &Builder, + rcc::Register Destination, rcc::Register Address, + const rcc::MachineMemOperand &Memory) { + auto Pending = Builder.buildInstr(opcode(rcc::riscv::InstructionOpcode::LD)); + if (!Pending || !Pending->addDef(Destination) || !Pending->addUse(Address) || + !Pending->addImmediate(0) || !Pending->addMemOperand(Memory)) { + Context.expect(false, "load construction must succeed"); + return nullptr; + } + auto Built = Pending->build(); + Context.expect(Built.has_value(), "load insertion must succeed"); + return Built.value_or(nullptr); +} + +void testDCEFixedPointAndDebugUses(TestContext &Context, const rcc::TargetDescription &Target) { + auto Fixture = makeFixture(Context, "dce", 1); + if (!Fixture.Function || Fixture.Entry == nullptr) + return; + rcc::MachineIRBuilder Builder(*Fixture.Function, Target); + Context.expect(Builder.setInsertPoint(*Fixture.Entry).has_value(), + "DCE insert point must be established"); + const rcc::PhysicalRegister X0 = physical(Context, rcc::riscv::PhysicalRegisterID::X0); + const rcc::PhysicalRegister X2 = physical(Context, rcc::riscv::PhysicalRegisterID::X2); + + const rcc::Register LiveRoot = makeGPR(Context, *Fixture.Function); + const rcc::Register LiveValue = makeGPR(Context, *Fixture.Function); + const rcc::Register DeadRoot = makeGPR(Context, *Fixture.Function); + const rcc::Register DeadValue = makeGPR(Context, *Fixture.Function); + (void)buildADDI(Context, Builder, LiveRoot, rcc::Register::fromPhysical(X0), 1); + (void)buildADDI(Context, Builder, LiveValue, LiveRoot, 2); + (void)buildADDI(Context, Builder, DeadRoot, rcc::Register::fromPhysical(X0), 3); + (void)buildADDI(Context, Builder, DeadValue, DeadRoot, 4); + + auto Debug = Builder.buildInstr(rcc::opcode(rcc::GenericOpcode::DBG_VALUE)); + Context.expect(Debug.has_value() && + Debug->addUse(DeadValue, {rcc::RegisterOperandFlag::Debug}).has_value() && + Debug->build().has_value(), + "debug-only use construction must succeed"); + const rcc::MachineMemOperand *Memory = makeMemory(Context, *Fixture.Function, true, false); + if (Memory == nullptr) + return; + rcc::MachineInstr *Store = buildStore(Context, Builder, LiveValue, X2, *Memory); + const std::size_t Before = Fixture.Entry->instructionCount(); + + rcc::MachineAnalysisManager Analyses; + rcc::MachineDCEPass Pass; + auto Result = Pass.run(*Fixture.Function, Target, Analyses); + if (!Result) + std::cerr << "machine DCE failure: " << Result.error().message() << '\n'; + Context.expect(Result.has_value() && Result->Changed, + "machine DCE must remove the debug-only dead chain"); + Context.expect(Fixture.Entry->instructionCount() + 2 == Before, + "machine DCE must reach a fixed point across the dead chain"); + Context.expect(Store != nullptr && Store->isLinked(), "machine DCE must preserve a store"); + Context.expect(!Fixture.Function->registerInfo().isKnownVirtualRegister(DeadRoot) && + !Fixture.Function->registerInfo().isKnownVirtualRegister(DeadValue), + "machine DCE must retire removed virtual registers"); + rcc::MachineInstr *DebugInstruction = nullptr; + for (rcc::MachineInstr *Instruction = Fixture.Entry->firstInstruction(); Instruction != nullptr; + Instruction = Instruction->next()) { + if (Instruction->opcode() == rcc::opcode(rcc::GenericOpcode::DBG_VALUE)) + DebugInstruction = Instruction; + } + const rcc::MachineOperand *DebugOperand = + DebugInstruction == nullptr ? nullptr : DebugInstruction->operandAt(0); + Context.expect(DebugOperand != nullptr && DebugOperand->registerValue().has_value() && + DebugOperand->registerValue()->isNoRegister(), + "machine DCE must clear a dangling debug register use"); +} + +void testMachineCombinerIdentityRules(TestContext &Context, const rcc::TargetDescription &Target) { + auto Fixture = makeFixture(Context, "combiner", 6); + if (!Fixture.Function || Fixture.Entry == nullptr) + return; + rcc::MachineIRBuilder Builder(*Fixture.Function, Target); + Context.expect(Builder.setInsertPoint(*Fixture.Entry).has_value(), + "combiner insert point must be established"); + const rcc::PhysicalRegister X0 = physical(Context, rcc::riscv::PhysicalRegisterID::X0); + const rcc::PhysicalRegister X2 = physical(Context, rcc::riscv::PhysicalRegisterID::X2); + const rcc::Register Seed = makeGPR(Context, *Fixture.Function); + const rcc::Register Identity = makeGPR(Context, *Fixture.Function); + const rcc::Register Consumer = makeGPR(Context, *Fixture.Function); + (void)buildADDI(Context, Builder, Seed, rcc::Register::fromPhysical(X0), 7); + rcc::MachineInstr *IdentityInstruction = buildADDI(Context, Builder, Identity, Seed, 0); + rcc::MachineInstr *ConsumerInstruction = buildADD(Context, Builder, Consumer, Identity, Seed); + const rcc::MachineMemOperand *Memory = makeMemory(Context, *Fixture.Function, true, false); + if (Memory == nullptr) + return; + (void)buildStore(Context, Builder, Consumer, X2, *Memory); + + rcc::MachineAnalysisManager Analyses; + rcc::MachineCombinerPass Pass(rcc::riscv::machineCombinerInfo(), + rcc::MachineCombinerStage::SelectedSSA); + auto Result = Pass.run(*Fixture.Function, Target, Analyses); + if (!Result) + std::cerr << "machine combiner failure: " << Result.error().message() << '\n'; + Context.expect(Result.has_value() && Result->Changed, + "machine combiner must apply a registered RV64GC identity rule"); + Context.expect(IdentityInstruction != nullptr && !IdentityInstruction->isLinked() && + !Fixture.Function->registerInfo().isKnownVirtualRegister(Identity), + "machine combiner must erase the identity and retire its result"); + const rcc::MachineOperand *ConsumerUse = + ConsumerInstruction == nullptr ? nullptr : ConsumerInstruction->operandAt(1); + Context.expect(ConsumerUse != nullptr && ConsumerUse->registerValue() == Seed, + "machine combiner executor must rewrite all result uses"); +} + +void testPostRAMachineCombinerIdentity(TestContext &Context, const rcc::TargetDescription &Target) { + auto Fixture = makeFixture(Context, "post_ra_combiner", 7); + if (!Fixture.Function || Fixture.Entry == nullptr) + return; + Fixture.Function->properties().clear(rcc::MachineFunctionProperty::IsSSA); + Fixture.Function->properties().set(rcc::MachineFunctionProperty::NoPHIs); + Fixture.Function->properties().set(rcc::MachineFunctionProperty::TiedOpsRewritten); + Fixture.Function->properties().set(rcc::MachineFunctionProperty::NoVRegs); + rcc::MachineIRBuilder Builder(*Fixture.Function, Target); + Context.expect(Builder.setInsertPoint(*Fixture.Entry).has_value(), + "post-RA combiner insert point must be established"); + const rcc::PhysicalRegister X10 = physical(Context, rcc::riscv::PhysicalRegisterID::X10); + rcc::MachineInstr *Identity = buildADDI(Context, Builder, rcc::Register::fromPhysical(X10), + rcc::Register::fromPhysical(X10), 0); + rcc::MachineAnalysisManager Analyses; + rcc::MachineCombinerPass Pass(rcc::riscv::machineCombinerInfo(), + rcc::MachineCombinerStage::PostRegisterAllocation); + auto Result = Pass.run(*Fixture.Function, Target, Analyses); + Context.expect( + Result.has_value() && Result->Changed && Identity != nullptr && !Identity->isLinked(), + "post-RA combiner must erase a physical-register no-op only when identities match"); +} + +void testCSERegisterAndMemoryRules(TestContext &Context, const rcc::TargetDescription &Target) { + auto Fixture = makeFixture(Context, "cse", 2); + if (!Fixture.Function || Fixture.Entry == nullptr) + return; + rcc::MachineIRBuilder Builder(*Fixture.Function, Target); + Context.expect(Builder.setInsertPoint(*Fixture.Entry).has_value(), + "CSE insert point must be established"); + const rcc::PhysicalRegister X0 = physical(Context, rcc::riscv::PhysicalRegisterID::X0); + + const rcc::Register Seed = makeGPR(Context, *Fixture.Function); + const rcc::Register First = makeGPR(Context, *Fixture.Function); + const rcc::Register Redundant = makeGPR(Context, *Fixture.Function); + const rcc::Register Consumer = makeGPR(Context, *Fixture.Function); + (void)buildADDI(Context, Builder, Seed, rcc::Register::fromPhysical(X0), 9); + rcc::MachineInstr *FirstInstruction = buildADDI(Context, Builder, First, Seed, 7); + rcc::MachineInstr *RedundantInstruction = buildADDI(Context, Builder, Redundant, Seed, 7); + rcc::MachineInstr *ConsumerInstruction = buildADD(Context, Builder, Consumer, Redundant, Seed); + + const rcc::Register MutableLoadOne = makeGPR(Context, *Fixture.Function); + const rcc::Register MutableLoadTwo = makeGPR(Context, *Fixture.Function); + const rcc::Register InvariantLoadOne = makeGPR(Context, *Fixture.Function); + const rcc::Register InvariantLoadTwo = makeGPR(Context, *Fixture.Function); + const rcc::MachineMemOperand *MutableMemory = + makeMemory(Context, *Fixture.Function, false, false); + const rcc::MachineMemOperand *InvariantMemory = + makeMemory(Context, *Fixture.Function, false, true); + if (MutableMemory == nullptr || InvariantMemory == nullptr) + return; + rcc::MachineInstr *MutableOne = buildLoad(Context, Builder, MutableLoadOne, Seed, *MutableMemory); + rcc::MachineInstr *MutableTwo = buildLoad(Context, Builder, MutableLoadTwo, Seed, *MutableMemory); + rcc::MachineInstr *InvariantOne = + buildLoad(Context, Builder, InvariantLoadOne, Seed, *InvariantMemory); + rcc::MachineInstr *InvariantTwo = + buildLoad(Context, Builder, InvariantLoadTwo, Seed, *InvariantMemory); + + rcc::MachineAnalysisManager Analyses; + rcc::MachineCSEPass Pass; + auto Result = Pass.run(*Fixture.Function, Target, Analyses); + if (!Result) + std::cerr << "machine CSE failure: " << Result.error().message() << '\n'; + Context.expect(Result.has_value() && Result->Changed, + "machine CSE must eliminate safe redundant expressions"); + Context.expect(FirstInstruction != nullptr && FirstInstruction->isLinked() && + RedundantInstruction != nullptr && !RedundantInstruction->isLinked(), + "machine CSE must keep the dominating expression only"); + const rcc::MachineOperand *ConsumerUse = + ConsumerInstruction == nullptr ? nullptr : ConsumerInstruction->operandAt(1); + Context.expect(ConsumerUse != nullptr && ConsumerUse->registerValue() == First, + "machine CSE must rewrite uses to the dominating result"); + Context.expect(MutableOne != nullptr && MutableOne->isLinked() && MutableTwo != nullptr && + MutableTwo->isLinked(), + "machine CSE must not merge mutable loads"); + Context.expect(InvariantOne != nullptr && InvariantOne->isLinked() && InvariantTwo != nullptr && + !InvariantTwo->isLinked(), + "machine CSE must merge invariant dereferenceable loads"); + Context.expect(!Fixture.Function->registerInfo().isKnownVirtualRegister(Redundant) && + !Fixture.Function->registerInfo().isKnownVirtualRegister(InvariantLoadTwo), + "machine CSE must retire redundant result registers"); +} + +void testCSEBudgetPreservesLegalMIR(TestContext &Context, const rcc::TargetDescription &Target) { + auto Fixture = makeFixture(Context, "cse_budget", 3); + if (!Fixture.Function || Fixture.Entry == nullptr) + return; + rcc::MachineIRBuilder Builder(*Fixture.Function, Target); + Context.expect(Builder.setInsertPoint(*Fixture.Entry).has_value(), + "CSE budget insert point must be established"); + const rcc::PhysicalRegister X0 = physical(Context, rcc::riscv::PhysicalRegisterID::X0); + const rcc::Register Seed = makeGPR(Context, *Fixture.Function); + const rcc::Register First = makeGPR(Context, *Fixture.Function); + const rcc::Register Second = makeGPR(Context, *Fixture.Function); + (void)buildADDI(Context, Builder, Seed, rcc::Register::fromPhysical(X0), 1); + (void)buildADDI(Context, Builder, First, Seed, 2); + rcc::MachineInstr *SecondInstruction = buildADDI(Context, Builder, Second, Seed, 2); + + rcc::MachineAnalysisManager Analyses; + rcc::MachineCSEPass Pass({.MaximumComparisons = 0}); + auto Result = Pass.run(*Fixture.Function, Target, Analyses); + if (!Result) + std::cerr << "machine CSE budget failure: " << Result.error().message() << '\n'; + Context.expect(Result.has_value() && !Result->Changed && SecondInstruction != nullptr && + SecondInstruction->isLinked(), + "machine CSE budget exhaustion must stop without rejecting or mutating MIR"); +} + +void testLICMHoistsOnlyInvariantInstructions(TestContext &Context, + const rcc::TargetDescription &Target) { + auto Fixture = makeFixture(Context, "licm", 4); + if (!Fixture.Function || Fixture.Entry == nullptr) + return; + auto Header = Fixture.Function->createBasicBlock(); + auto Body = Fixture.Function->createBasicBlock(); + auto Exit = Fixture.Function->createBasicBlock(); + Context.expect(Header.has_value() && Body.has_value() && Exit.has_value() && + Fixture.Function->appendBlock(**Header).has_value() && + Fixture.Function->appendBlock(**Body).has_value() && + Fixture.Function->appendBlock(**Exit).has_value(), + "LICM loop blocks must be created"); + if (!Header || !Body || !Exit) + return; + auto Half = rcc::BranchProbability::fromFraction(1, 2); + Context.expect(Half.has_value(), "LICM branch probability must be created"); + if (!Half) + return; + auto Updater = Fixture.Function->cfgUpdater(); + Context.expect( + Updater.addSuccessor(*Fixture.Entry, **Header, rcc::BranchProbability::one()).has_value() && + Updater.addSuccessor(**Header, **Body, *Half).has_value() && + Updater.addSuccessor(**Header, **Exit, *Half).has_value() && + Updater.addSuccessor(**Body, **Header, rcc::BranchProbability::one()).has_value(), + "LICM loop CFG must be connected"); + + rcc::MachineIRBuilder Builder(*Fixture.Function, Target); + Context.expect(Builder.setInsertPoint(*Fixture.Entry).has_value(), + "LICM preheader insertion point must be established"); + const rcc::PhysicalRegister X0 = physical(Context, rcc::riscv::PhysicalRegisterID::X0); + const rcc::Register Seed = makeGPR(Context, *Fixture.Function); + (void)buildADDI(Context, Builder, Seed, rcc::Register::fromPhysical(X0), 1); + + Context.expect(Builder.setInsertPoint(**Body).has_value(), + "LICM body insertion point must be established"); + const rcc::Register HoistedValue = makeGPR(Context, *Fixture.Function); + const rcc::Register DependentValue = makeGPR(Context, *Fixture.Function); + rcc::MachineInstr *Hoisted = buildADDI(Context, Builder, HoistedValue, Seed, 8); + rcc::MachineInstr *Dependent = buildADDI(Context, Builder, DependentValue, HoistedValue, 9); + const rcc::Register MutableLoad = makeGPR(Context, *Fixture.Function); + const rcc::MachineMemOperand *Memory = makeMemory(Context, *Fixture.Function, false, false); + rcc::MachineInstr *Load = + Memory == nullptr ? nullptr : buildLoad(Context, Builder, MutableLoad, Seed, *Memory); + + rcc::MachineAnalysisManager Analyses; + rcc::MachineLICMPass Pass; + auto Result = Pass.run(*Fixture.Function, Target, Analyses); + if (!Result) + std::cerr << "machine LICM failure: " << Result.error().message() << '\n'; + Context.expect(Result.has_value() && Result->Changed, + "machine LICM must hoist loop-invariant instructions"); + Context.expect(Hoisted != nullptr && Hoisted->parent() == Fixture.Entry && Dependent != nullptr && + Dependent->parent() == Fixture.Entry, + "machine LICM must reach a fixed point for dependent invariants"); + Context.expect(Load != nullptr && Load->parent() == *Body, + "machine LICM must keep mutable loads in the loop"); +} + +void testMachineSinkUsesColdUniqueSuccessor(TestContext &Context, + const rcc::TargetDescription &Target) { + auto Fixture = makeFixture(Context, "sink", 5); + if (!Fixture.Function || Fixture.Entry == nullptr) + return; + auto Cold = Fixture.Function->createBasicBlock(); + auto Hot = Fixture.Function->createBasicBlock(); + Context.expect(Cold.has_value() && Hot.has_value() && + Fixture.Function->appendBlock(**Cold).has_value() && + Fixture.Function->appendBlock(**Hot).has_value(), + "machine sink successor blocks must be created"); + if (!Cold || !Hot) + return; + auto ColdProbability = rcc::BranchProbability::fromFraction(1, 10); + auto HotProbability = rcc::BranchProbability::fromFraction(9, 10); + Context.expect(ColdProbability.has_value() && HotProbability.has_value(), + "machine sink probabilities must be created"); + if (!ColdProbability || !HotProbability) + return; + auto Updater = Fixture.Function->cfgUpdater(); + Context.expect(Updater.addSuccessor(*Fixture.Entry, **Cold, *ColdProbability).has_value() && + Updater.addSuccessor(*Fixture.Entry, **Hot, *HotProbability).has_value(), + "machine sink CFG must be connected"); + + rcc::MachineIRBuilder Builder(*Fixture.Function, Target); + Context.expect(Builder.setInsertPoint(*Fixture.Entry).has_value(), + "machine sink source insertion point must be established"); + const rcc::PhysicalRegister X0 = physical(Context, rcc::riscv::PhysicalRegisterID::X0); + const rcc::Register Seed = makeGPR(Context, *Fixture.Function); + const rcc::Register SunkValue = makeGPR(Context, *Fixture.Function); + (void)buildADDI(Context, Builder, Seed, rcc::Register::fromPhysical(X0), 1); + rcc::MachineInstr *Sunk = buildADDI(Context, Builder, SunkValue, Seed, 4); + + Context.expect(Builder.setInsertPoint(**Cold).has_value(), + "machine sink destination insertion point must be established"); + const rcc::Register Consumer = makeGPR(Context, *Fixture.Function); + rcc::MachineInstr *Use = buildADD(Context, Builder, Consumer, SunkValue, Seed); + + rcc::MachineAnalysisManager Analyses; + rcc::MachineSinkPass Pass; + auto Result = Pass.run(*Fixture.Function, Target, Analyses); + if (!Result) + std::cerr << "machine sink failure: " << Result.error().message() << '\n'; + Context.expect(Result.has_value() && Result->Changed, + "machine sink must move a cold-path-only expression"); + Context.expect(Sunk != nullptr && Sunk->parent() == *Cold && Use != nullptr && + Sunk->next() == Use, + "machine sink must place the definition immediately before its first use"); +} + +void testPostRACodeMotion(TestContext &Context, const rcc::TargetDescription &Target) { + auto LICMFixture = makeFixture(Context, "post-ra-licm", 10); + if (!LICMFixture.Function || LICMFixture.Entry == nullptr) + return; + auto Header = LICMFixture.Function->createBasicBlock(); + auto Body = LICMFixture.Function->createBasicBlock(); + auto Exit = LICMFixture.Function->createBasicBlock(); + if (!Header || !Body || !Exit || !LICMFixture.Function->appendBlock(**Header) || + !LICMFixture.Function->appendBlock(**Body) || !LICMFixture.Function->appendBlock(**Exit)) { + Context.expect(false, "post-RA LICM blocks must be created"); + return; + } + auto Half = rcc::BranchProbability::fromFraction(1, 2); + if (!Half) + return; + auto LICMUpdater = LICMFixture.Function->cfgUpdater(); + if (!LICMUpdater.addSuccessor(*LICMFixture.Entry, **Header, rcc::BranchProbability::one()) || + !LICMUpdater.addSuccessor(**Header, **Body, *Half) || + !LICMUpdater.addSuccessor(**Header, **Exit, *Half) || + !LICMUpdater.addSuccessor(**Body, **Header, rcc::BranchProbability::one())) { + Context.expect(false, "post-RA LICM CFG must be connected"); + return; + } + rcc::MachineIRBuilder LICMBuilder(*LICMFixture.Function, Target); + if (!LICMBuilder.setInsertPoint(*LICMFixture.Entry)) + return; + const rcc::Register X0 = + rcc::Register::fromPhysical(physical(Context, rcc::riscv::PhysicalRegisterID::X0)); + const rcc::Register X2 = + rcc::Register::fromPhysical(physical(Context, rcc::riscv::PhysicalRegisterID::X2)); + const rcc::Register X10 = + rcc::Register::fromPhysical(physical(Context, rcc::riscv::PhysicalRegisterID::X10)); + const rcc::Register X12 = + rcc::Register::fromPhysical(physical(Context, rcc::riscv::PhysicalRegisterID::X12)); + const rcc::Register X13 = + rcc::Register::fromPhysical(physical(Context, rcc::riscv::PhysicalRegisterID::X13)); + (void)buildADDI(Context, LICMBuilder, X10, X0, 1); + if (!LICMBuilder.setInsertPoint(**Header)) + return; + rcc::MachineInstr *Hoisted = buildADDI(Context, LICMBuilder, X12, X10, 4); + if (Hoisted == nullptr) + return; + Hoisted->setFlags({rcc::MachineInstrFlag::NoFPExcept}); + if (!LICMBuilder.setInsertPoint(**Body)) + return; + (void)buildADDI(Context, LICMBuilder, X13, X12, 1); + if (!LICMBuilder.setInsertPoint(**Exit)) + return; + const rcc::MachineMemOperand *LICMMemory = + makeMemory(Context, *LICMFixture.Function, true, false); + if (LICMMemory == nullptr) + return; + (void)buildStore(Context, LICMBuilder, X12, *X2.physicalRegister(), *LICMMemory); + setPostRAProperties(*LICMFixture.Function); + Context.expect(rcc::rebuildMachineLiveness(*LICMFixture.Function, Target).has_value(), + "post-RA LICM fixture liveness must be built"); + rcc::MachineAnalysisManager LICMAnalyses; + rcc::MachineLICMPass PostRALICM(rcc::MachineCodeMotionStage::PostRegisterAllocation); + auto LICMResult = PostRALICM.run(*LICMFixture.Function, Target, LICMAnalyses); + Context.expect(LICMResult && LICMResult->Changed && Hoisted->parent() == LICMFixture.Entry && + rcc::verifyTrackedMachineLiveness(*LICMFixture.Function, Target).has_value(), + "post-RA LICM must hoist a safe physical-register invariant and repair liveness"); + + auto SinkFixture = makeFixture(Context, "post-ra-sink", 11); + if (!SinkFixture.Function || SinkFixture.Entry == nullptr) + return; + auto Cold = SinkFixture.Function->createBasicBlock(); + auto Hot = SinkFixture.Function->createBasicBlock(); + if (!Cold || !Hot || !SinkFixture.Function->appendBlock(**Cold) || + !SinkFixture.Function->appendBlock(**Hot)) { + return; + } + auto ColdProbability = rcc::BranchProbability::fromFraction(1, 10); + auto HotProbability = rcc::BranchProbability::fromFraction(9, 10); + if (!ColdProbability || !HotProbability) + return; + auto SinkUpdater = SinkFixture.Function->cfgUpdater(); + if (!SinkUpdater.addSuccessor(*SinkFixture.Entry, **Cold, *ColdProbability) || + !SinkUpdater.addSuccessor(*SinkFixture.Entry, **Hot, *HotProbability)) { + return; + } + rcc::MachineIRBuilder SinkBuilder(*SinkFixture.Function, Target); + if (!SinkBuilder.setInsertPoint(*SinkFixture.Entry)) + return; + (void)buildADDI(Context, SinkBuilder, X10, X0, 2); + rcc::MachineInstr *Sunk = buildADDI(Context, SinkBuilder, X12, X10, 8); + if (Sunk == nullptr) + return; + Sunk->setFlags({rcc::MachineInstrFlag::NoFPExcept}); + if (!SinkBuilder.setInsertPoint(**Cold)) + return; + rcc::MachineInstr *ColdUse = buildADDI(Context, SinkBuilder, X13, X12, 1); + setPostRAProperties(*SinkFixture.Function); + Context.expect(rcc::rebuildMachineLiveness(*SinkFixture.Function, Target).has_value(), + "post-RA sink fixture liveness must be built"); + rcc::MachineAnalysisManager SinkAnalyses; + rcc::MachineSinkPass PostRASink(rcc::MachineCodeMotionStage::PostRegisterAllocation); + auto SinkResult = PostRASink.run(*SinkFixture.Function, Target, SinkAnalyses); + Context.expect(SinkResult && SinkResult->Changed && Sunk->parent() == *Cold && + Sunk->next() == ColdUse && + rcc::verifyTrackedMachineLiveness(*SinkFixture.Function, Target).has_value(), + "post-RA sinking must move a physical definition to its sole cold use"); +} + +void testMemoryFoldingContract(TestContext &Context, const rcc::TargetDescription &Target) { + auto BuildCandidate = [&](std::string Name, std::uint64_t ID) { + Fixture Candidate = makeFixture(Context, std::move(Name), ID); + if (!Candidate.Function || Candidate.Entry == nullptr) + return Candidate; + rcc::MachineIRBuilder Builder(*Candidate.Function, Target); + if (!Builder.setInsertPoint(*Candidate.Entry)) + return Candidate; + const rcc::PhysicalRegister X0 = physical(Context, rcc::riscv::PhysicalRegisterID::X0); + const rcc::PhysicalRegister X2 = physical(Context, rcc::riscv::PhysicalRegisterID::X2); + const rcc::Register Address = makeGPR(Context, *Candidate.Function); + const rcc::Register Loaded = makeGPR(Context, *Candidate.Function); + const rcc::Register FoldedResult = makeGPR(Context, *Candidate.Function); + (void)buildADDI(Context, Builder, Address, rcc::Register::fromPhysical(X0), 0); + const rcc::MachineMemOperand *LoadMemory = + makeMemory(Context, *Candidate.Function, false, false); + const rcc::MachineMemOperand *StoreMemory = + makeMemory(Context, *Candidate.Function, true, false); + if (LoadMemory == nullptr || StoreMemory == nullptr) + return Candidate; + (void)buildLoad(Context, Builder, Loaded, Address, *LoadMemory); + (void)buildADDI(Context, Builder, FoldedResult, Loaded, 0); + (void)buildStore(Context, Builder, FoldedResult, X2, *StoreMemory); + return Candidate; + }; + + Fixture Folded = BuildCandidate("memory-fold", 8); + if (!Folded.Function || Folded.Entry == nullptr) + return; + TestMemoryFoldingInfo GoodInfo; + rcc::MachineAnalysisManager Analyses; + rcc::MachineMemoryFoldingPass Pass(GoodInfo); + auto Result = Pass.run(*Folded.Function, Target, Analyses); + if (!Result) + std::cerr << "machine memory folding failure: " << Result.error().message() << '\n'; + std::size_t LoadCount = 0; + rcc::MachineInstr *FoldedLoad = nullptr; + for (rcc::MachineInstr *Instruction = Folded.Entry->firstInstruction(); Instruction != nullptr; + Instruction = Instruction->next()) { + if (Instruction->opcode() == opcode(rcc::riscv::InstructionOpcode::LD)) { + ++LoadCount; + FoldedLoad = Instruction; + } + } + Context.expect(Result && Result->Changed && LoadCount == 1 && FoldedLoad != nullptr && + FoldedLoad->memOperands().size() == 1, + "memory folding must replace an adjacent load-use pair and migrate its MMO"); + + Fixture Rejected = BuildCandidate("memory-fold-missing-mmo", 9); + if (!Rejected.Function || Rejected.Entry == nullptr) + return; + rcc::MachineInstr *OriginalLoad = Rejected.Entry->firstInstruction(); + OriginalLoad = OriginalLoad == nullptr ? nullptr : OriginalLoad->next(); + rcc::MachineInstr *OriginalConsumer = OriginalLoad == nullptr ? nullptr : OriginalLoad->next(); + const std::size_t OriginalCount = Rejected.Entry->instructionCount(); + TestMemoryFoldingInfo BadInfo(true); + rcc::MachineMemoryFoldingPass BadPass(BadInfo); + auto Failure = BadPass.run(*Rejected.Function, Target, Analyses); + Context.expect(!Failure && Failure.error().code() == rcc::ErrorCode::VerificationError && + Rejected.Entry->instructionCount() == OriginalCount && + OriginalLoad != nullptr && OriginalLoad->isLinked() && + OriginalConsumer != nullptr && OriginalConsumer->isLinked(), + "memory folding must reject missing MMO migration without mutating the function"); +} + +} // namespace + +int main() { + TestContext Context; + auto Target = rcc::riscv::createTargetDescription(); + Context.expect(Target.has_value(), "optimization target construction must succeed"); + if (!Target) + return Context.result(); + testDCEFixedPointAndDebugUses(Context, *Target); + testMachineCombinerIdentityRules(Context, *Target); + testPostRAMachineCombinerIdentity(Context, *Target); + testCSERegisterAndMemoryRules(Context, *Target); + testCSEBudgetPreservesLegalMIR(Context, *Target); + testLICMHoistsOnlyInvariantInstructions(Context, *Target); + testMachineSinkUsesColdUniqueSuccessor(Context, *Target); + testPostRACodeMotion(Context, *Target); + testMemoryFoldingContract(Context, *Target); + return Context.result(); +} |