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// SPDX-License-Identifier: GPL-3.0-or-later
#include "rcc/CodeGen/GlobalISel/GIMatchTableExecutor.h"
#include "rcc/CodeGen/LowLevelType.h"
#include "rcc/CodeGen/MachineFunction.h"
#include "rcc/CodeGen/MachineInstr.h"
#include "rcc/CodeGen/MachineOperand.h"
#include "rcc/CodeGen/MachineRegisterInfo.h"
#include "rcc/CodeGen/TargetDescription.h"
#include <cstddef>
#include <optional>
#include <vector>
namespace rcc {
namespace {
[[nodiscard]] Expected<std::optional<LowLevelType>> operandType(const MachineInstr &Instruction,
const MachineFunction &Function,
std::size_t OperandIndex) {
const MachineOperand *Operand = Instruction.operandAt(OperandIndex);
const Register *Reg = Operand == nullptr ? nullptr : Operand->getIf<Register>();
if (Reg == nullptr || !Reg->isVirtual())
return std::optional<LowLevelType>{};
auto Info = Function.registerInfo().virtualRegisterInfo(*Reg);
if (!Info)
return std::unexpected(Info.error());
return Info->get().Type;
}
[[nodiscard]] Expected<bool> matchesType(const MachineInstr &Instruction,
const MachineFunction &Function,
const GIMatchTableInstruction &Step) {
auto Type = operandType(Instruction, Function, Step.OperandIndex);
if (!Type)
return std::unexpected(Type.error());
if (!*Type)
return false;
const auto Kind = static_cast<GIMatchTypeKind>(Step.Auxiliary);
switch (Kind) {
case GIMatchTypeKind::Any:
return Step.Value == 0 || (*Type)->scalarBitWidth() == Step.Value;
case GIMatchTypeKind::Scalar:
return (*Type)->isCategoryNeutralScalar() && (*Type)->scalarBitWidth() == Step.Value;
case GIMatchTypeKind::Pointer:
return (*Type)->isPointer() && (*Type)->scalarBitWidth() == Step.Value;
}
return makeUnexpected(ErrorCode::VerificationError,
"generated match table has an invalid type predicate");
}
[[nodiscard]] Expected<bool> matchesBank(const MachineInstr &Instruction,
const MachineFunction &Function,
const GIMatchTableInstruction &Step) {
const MachineOperand *Operand = Instruction.operandAt(Step.OperandIndex);
const Register *Reg = Operand == nullptr ? nullptr : Operand->getIf<Register>();
if (Reg == nullptr || !Reg->isVirtual())
return false;
auto Info = Function.registerInfo().virtualRegisterInfo(*Reg);
if (!Info)
return std::unexpected(Info.error());
const VirtualRegisterInfo &RegisterInfo = Info->get();
if (!RegisterInfo.Bank)
return false;
return RegisterInfo.Bank->value() == Step.Value;
}
[[nodiscard]] Expected<bool> matchesClass(const MachineInstr &Instruction,
const MachineFunction &Function,
const GIMatchTableInstruction &Step) {
const MachineOperand *Operand = Instruction.operandAt(Step.OperandIndex);
const Register *Reg = Operand == nullptr ? nullptr : Operand->getIf<Register>();
if (Reg == nullptr || !Reg->isVirtual())
return false;
auto Info = Function.registerInfo().virtualRegisterInfo(*Reg);
if (!Info)
return std::unexpected(Info.error());
const VirtualRegisterInfo &RegisterInfo = Info->get();
if (!RegisterInfo.RegClass)
return false;
return RegisterInfo.RegClass->value() == Step.Value;
}
struct MatchedRule final {
Opcode ResultOpcode;
std::vector<std::int64_t> AppendedImmediates;
};
[[nodiscard]] Expected<std::optional<MatchedRule>> matchRule(const GIMatchTable &Table,
const GIMatchTableRule &Rule,
const MachineInstr &Instruction,
const MachineFunction &Function) {
const std::size_t First = Rule.FirstInstruction;
const std::size_t Count = Rule.InstructionCount;
if (First > Table.Instructions.size() || Count > Table.Instructions.size() - First) {
return makeUnexpected(ErrorCode::VerificationError,
"generated match table rule has an invalid instruction range");
}
MatchedRule Result;
bool HasResultOpcode = false;
bool Applying = false;
bool Complete = false;
for (std::size_t Index = First; Index < First + Count; ++Index) {
const GIMatchTableInstruction &Step = Table.Instructions[Index];
switch (Step.Opcode) {
case GIMatchTableOpcode::CheckOpcode:
if (Applying)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table performs a predicate after rendering");
if (Instruction.opcode().value() != Step.Value)
return std::optional<MatchedRule>{};
break;
case GIMatchTableOpcode::CheckOperandType: {
if (Applying)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table performs a predicate after rendering");
auto Matched = matchesType(Instruction, Function, Step);
if (!Matched)
return std::unexpected(Matched.error());
if (!*Matched)
return std::optional<MatchedRule>{};
break;
}
case GIMatchTableOpcode::CheckOperandBank: {
if (Applying)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table performs a predicate after rendering");
auto Matched = matchesBank(Instruction, Function, Step);
if (!Matched)
return std::unexpected(Matched.error());
if (!*Matched)
return std::optional<MatchedRule>{};
break;
}
case GIMatchTableOpcode::CheckOperandClass: {
if (Applying)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table performs a predicate after rendering");
auto Matched = matchesClass(Instruction, Function, Step);
if (!Matched)
return std::unexpected(Matched.error());
if (!*Matched)
return std::optional<MatchedRule>{};
break;
}
case GIMatchTableOpcode::MutateOpcode:
if (Complete || HasResultOpcode || Step.Value == 0)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table has an invalid opcode mutation");
Applying = true;
Result.ResultOpcode = Opcode::fromValue(Step.Value);
HasResultOpcode = true;
break;
case GIMatchTableOpcode::AppendImmediate:
if (Complete)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table renders after completion");
Applying = true;
Result.AppendedImmediates.push_back(Step.Immediate);
break;
case GIMatchTableOpcode::Complete:
if (Complete || !HasResultOpcode || Index + 1 != First + Count)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table has an invalid completion action");
Complete = true;
break;
}
}
if (!Complete || !HasResultOpcode)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table rule does not complete rendering");
return std::optional<MatchedRule>(std::move(Result));
}
[[nodiscard]] Expected<void> applyRule(const MatchedRule &Rule, MachineInstr &Instruction,
const TargetDescription &Target) {
const InstructionDescriptor *Descriptor = Target.instructionDescriptor(Rule.ResultOpcode);
if (Descriptor == nullptr)
return makeUnexpected(ErrorCode::VerificationError,
"generated match table selects an unknown instruction opcode");
if (!Descriptor->Variadic &&
Descriptor->Operands.size() != Instruction.operandCount() + Rule.AppendedImmediates.size()) {
return makeUnexpected(ErrorCode::VerificationError,
"generated match table result has an incompatible operand count");
}
const Opcode OriginalOpcode = Instruction.opcode();
auto SetOpcode = Instruction.setOpcode(Rule.ResultOpcode);
if (!SetOpcode)
return std::unexpected(SetOpcode.error());
const std::size_t OriginalOperandCount = Instruction.operandCount();
for (const std::int64_t Immediate : Rule.AppendedImmediates) {
auto Added = Instruction.addOperand(MachineOperand::immediate(Immediate));
if (Added)
continue;
while (Instruction.operandCount() > OriginalOperandCount) {
auto Removed = Instruction.eraseOperand(Instruction.operandCount() - 1U);
if (!Removed)
return std::unexpected(Removed.error());
}
auto Restored = Instruction.setOpcode(OriginalOpcode);
if (!Restored)
return std::unexpected(Restored.error());
return std::unexpected(Added.error());
}
return {};
}
} // namespace
Expected<bool> GIMatchTableExecutor::match(const GIMatchTable &Table,
const MachineInstr &Instruction,
const MachineFunction &Function,
const TargetDescription &Target) const {
for (const GIMatchTableRule &Rule : Table.Rules) {
auto Match = matchRule(Table, Rule, Instruction, Function);
if (!Match)
return std::unexpected(Match.error());
if (!*Match)
continue;
if (Target.instructionDescriptor((*Match)->ResultOpcode) == nullptr) {
return makeUnexpected(ErrorCode::VerificationError,
"generated match table selects an unknown instruction opcode");
}
return true;
}
return false;
}
Expected<bool> GIMatchTableExecutor::select(const GIMatchTable &Table, MachineInstr &Instruction,
MachineFunction &Function,
const TargetDescription &Target) const {
for (const GIMatchTableRule &Rule : Table.Rules) {
auto Match = matchRule(Table, Rule, Instruction, Function);
if (!Match)
return std::unexpected(Match.error());
if (!*Match)
continue;
auto Applied = applyRule(**Match, Instruction, Target);
if (!Applied)
return std::unexpected(Applied.error());
return true;
}
return false;
}
} // namespace rcc
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