llvm-project/llvm/utils/TableGen/GlobalISelEmitter.cpp

1791 lines
64 KiB
C++

//===- GlobalISelEmitter.cpp - Generate an instruction selector -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file
/// This tablegen backend emits code for use by the GlobalISel instruction
/// selector. See include/llvm/CodeGen/TargetGlobalISel.td.
///
/// This file analyzes the patterns recognized by the SelectionDAGISel tablegen
/// backend, filters out the ones that are unsupported, maps
/// SelectionDAG-specific constructs to their GlobalISel counterpart
/// (when applicable: MVT to LLT; SDNode to generic Instruction).
///
/// Not all patterns are supported: pass the tablegen invocation
/// "-warn-on-skipped-patterns" to emit a warning when a pattern is skipped,
/// as well as why.
///
/// The generated file defines a single method:
/// bool <Target>InstructionSelector::selectImpl(MachineInstr &I) const;
/// intended to be used in InstructionSelector::select as the first-step
/// selector for the patterns that don't require complex C++.
///
/// FIXME: We'll probably want to eventually define a base
/// "TargetGenInstructionSelector" class.
///
//===----------------------------------------------------------------------===//
#include "CodeGenDAGPatterns.h"
#include "SubtargetFeatureInfo.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineValueType.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/LowLevelTypeImpl.h"
#include "llvm/Support/ScopedPrinter.h"
#include "llvm/TableGen/Error.h"
#include "llvm/TableGen/Record.h"
#include "llvm/TableGen/TableGenBackend.h"
#include <string>
#include <numeric>
using namespace llvm;
#define DEBUG_TYPE "gisel-emitter"
STATISTIC(NumPatternTotal, "Total number of patterns");
STATISTIC(NumPatternImported, "Number of patterns imported from SelectionDAG");
STATISTIC(NumPatternImportsSkipped, "Number of SelectionDAG imports skipped");
STATISTIC(NumPatternEmitted, "Number of patterns emitted");
cl::OptionCategory GlobalISelEmitterCat("Options for -gen-global-isel");
static cl::opt<bool> WarnOnSkippedPatterns(
"warn-on-skipped-patterns",
cl::desc("Explain why a pattern was skipped for inclusion "
"in the GlobalISel selector"),
cl::init(false), cl::cat(GlobalISelEmitterCat));
namespace {
//===- Helper functions ---------------------------------------------------===//
/// This class stands in for LLT wherever we want to tablegen-erate an
/// equivalent at compiler run-time.
class LLTCodeGen {
private:
LLT Ty;
public:
LLTCodeGen(const LLT &Ty) : Ty(Ty) {}
void emitCxxConstructorCall(raw_ostream &OS) const {
if (Ty.isScalar()) {
OS << "LLT::scalar(" << Ty.getSizeInBits() << ")";
return;
}
if (Ty.isVector()) {
OS << "LLT::vector(" << Ty.getNumElements() << ", " << Ty.getScalarSizeInBits()
<< ")";
return;
}
llvm_unreachable("Unhandled LLT");
}
const LLT &get() const { return Ty; }
};
class InstructionMatcher;
/// Convert an MVT to an equivalent LLT if possible, or the invalid LLT() for
/// MVTs that don't map cleanly to an LLT (e.g., iPTR, *any, ...).
static Optional<LLTCodeGen> MVTToLLT(MVT::SimpleValueType SVT) {
MVT VT(SVT);
if (VT.isVector() && VT.getVectorNumElements() != 1)
return LLTCodeGen(LLT::vector(VT.getVectorNumElements(), VT.getScalarSizeInBits()));
if (VT.isInteger() || VT.isFloatingPoint())
return LLTCodeGen(LLT::scalar(VT.getSizeInBits()));
return None;
}
static std::string explainPredicates(const TreePatternNode *N) {
std::string Explanation = "";
StringRef Separator = "";
for (const auto &P : N->getPredicateFns()) {
Explanation +=
(Separator + P.getOrigPatFragRecord()->getRecord()->getName()).str();
if (P.isAlwaysTrue())
Explanation += " always-true";
if (P.isImmediatePattern())
Explanation += " immediate";
}
return Explanation;
}
std::string explainOperator(Record *Operator) {
if (Operator->isSubClassOf("SDNode"))
return " (" + Operator->getValueAsString("Opcode") + ")";
if (Operator->isSubClassOf("Intrinsic"))
return (" (Operator is an Intrinsic, " + Operator->getName() + ")").str();
return " (Operator not understood)";
}
/// Helper function to let the emitter report skip reason error messages.
static Error failedImport(const Twine &Reason) {
return make_error<StringError>(Reason, inconvertibleErrorCode());
}
static Error isTrivialOperatorNode(const TreePatternNode *N) {
std::string Explanation = "";
std::string Separator = "";
if (N->isLeaf()) {
Explanation = "Is a leaf";
Separator = ", ";
}
if (N->hasAnyPredicate()) {
Explanation = Separator + "Has a predicate (" + explainPredicates(N) + ")";
Separator = ", ";
}
if (N->getTransformFn()) {
Explanation += Separator + "Has a transform function";
Separator = ", ";
}
if (!N->isLeaf() && !N->hasAnyPredicate() && !N->getTransformFn())
return Error::success();
return failedImport(Explanation);
}
//===- Matchers -----------------------------------------------------------===//
class OperandMatcher;
class MatchAction;
/// Generates code to check that a match rule matches.
class RuleMatcher {
/// A list of matchers that all need to succeed for the current rule to match.
/// FIXME: This currently supports a single match position but could be
/// extended to support multiple positions to support div/rem fusion or
/// load-multiple instructions.
std::vector<std::unique_ptr<InstructionMatcher>> Matchers;
/// A list of actions that need to be taken when all predicates in this rule
/// have succeeded.
std::vector<std::unique_ptr<MatchAction>> Actions;
/// A map of instruction matchers to the local variables created by
/// emitCxxCaptureStmts().
std::map<const InstructionMatcher *, std::string> InsnVariableNames;
/// ID for the next instruction variable defined with defineInsnVar()
unsigned NextInsnVarID;
std::vector<Record *> RequiredFeatures;
public:
RuleMatcher()
: Matchers(), Actions(), InsnVariableNames(), NextInsnVarID(0) {}
RuleMatcher(RuleMatcher &&Other) = default;
RuleMatcher &operator=(RuleMatcher &&Other) = default;
InstructionMatcher &addInstructionMatcher();
void addRequiredFeature(Record *Feature);
template <class Kind, class... Args> Kind &addAction(Args &&... args);
std::string defineInsnVar(raw_ostream &OS, const InstructionMatcher &Matcher,
StringRef Value);
StringRef getInsnVarName(const InstructionMatcher &InsnMatcher) const;
void emitCxxCapturedInsnList(raw_ostream &OS);
void emitCxxCaptureStmts(raw_ostream &OS, StringRef Expr);
void emit(raw_ostream &OS, SubtargetFeatureInfoMap SubtargetFeatures);
/// Compare the priority of this object and B.
///
/// Returns true if this object is more important than B.
bool isHigherPriorityThan(const RuleMatcher &B) const;
/// Report the maximum number of temporary operands needed by the rule
/// matcher.
unsigned countRendererFns() const;
// FIXME: Remove this as soon as possible
InstructionMatcher &insnmatcher_front() const { return *Matchers.front(); }
};
template <class PredicateTy> class PredicateListMatcher {
private:
typedef std::vector<std::unique_ptr<PredicateTy>> PredicateVec;
PredicateVec Predicates;
public:
/// Construct a new operand predicate and add it to the matcher.
template <class Kind, class... Args>
Kind &addPredicate(Args&&... args) {
Predicates.emplace_back(
llvm::make_unique<Kind>(std::forward<Args>(args)...));
return *static_cast<Kind *>(Predicates.back().get());
}
typename PredicateVec::const_iterator predicates_begin() const { return Predicates.begin(); }
typename PredicateVec::const_iterator predicates_end() const { return Predicates.end(); }
iterator_range<typename PredicateVec::const_iterator> predicates() const {
return make_range(predicates_begin(), predicates_end());
}
typename PredicateVec::size_type predicates_size() const { return Predicates.size(); }
/// Emit a C++ expression that tests whether all the predicates are met.
template <class... Args>
void emitCxxPredicateListExpr(raw_ostream &OS, Args &&... args) const {
if (Predicates.empty()) {
OS << "true";
return;
}
StringRef Separator = "";
for (const auto &Predicate : predicates()) {
OS << Separator << "(";
Predicate->emitCxxPredicateExpr(OS, std::forward<Args>(args)...);
OS << ")";
Separator = " &&\n";
}
}
};
/// Generates code to check a predicate of an operand.
///
/// Typical predicates include:
/// * Operand is a particular register.
/// * Operand is assigned a particular register bank.
/// * Operand is an MBB.
class OperandPredicateMatcher {
public:
/// This enum is used for RTTI and also defines the priority that is given to
/// the predicate when generating the matcher code. Kinds with higher priority
/// must be tested first.
///
/// The relative priority of OPM_LLT, OPM_RegBank, and OPM_MBB do not matter
/// but OPM_Int must have priority over OPM_RegBank since constant integers
/// are represented by a virtual register defined by a G_CONSTANT instruction.
enum PredicateKind {
OPM_ComplexPattern,
OPM_Instruction,
OPM_Int,
OPM_LLT,
OPM_RegBank,
OPM_MBB,
};
protected:
PredicateKind Kind;
public:
OperandPredicateMatcher(PredicateKind Kind) : Kind(Kind) {}
virtual ~OperandPredicateMatcher() {}
PredicateKind getKind() const { return Kind; }
/// Return the OperandMatcher for the specified operand or nullptr if there
/// isn't one by that name in this operand predicate matcher.
///
/// InstructionOperandMatcher is the only subclass that can return non-null
/// for this.
virtual Optional<const OperandMatcher *>
getOptionalOperand(StringRef SymbolicName) const {
assert(!SymbolicName.empty() && "Cannot lookup unnamed operand");
return None;
}
/// Emit C++ statements to capture instructions into local variables.
///
/// Only InstructionOperandMatcher needs to do anything for this method.
virtual void emitCxxCaptureStmts(raw_ostream &OS, RuleMatcher &Rule,
StringRef Expr) const {}
/// Emit a C++ expression that checks the predicate for the given operand.
virtual void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const = 0;
/// Compare the priority of this object and B.
///
/// Returns true if this object is more important than B.
virtual bool isHigherPriorityThan(const OperandPredicateMatcher &B) const {
return Kind < B.Kind;
};
/// Report the maximum number of temporary operands needed by the predicate
/// matcher.
virtual unsigned countRendererFns() const { return 0; }
};
/// Generates code to check that an operand is a particular LLT.
class LLTOperandMatcher : public OperandPredicateMatcher {
protected:
LLTCodeGen Ty;
public:
LLTOperandMatcher(const LLTCodeGen &Ty)
: OperandPredicateMatcher(OPM_LLT), Ty(Ty) {}
static bool classof(const OperandPredicateMatcher *P) {
return P->getKind() == OPM_LLT;
}
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
OS << "MRI.getType(" << OperandExpr << ".getReg()) == (";
Ty.emitCxxConstructorCall(OS);
OS << ")";
}
};
/// Generates code to check that an operand is a particular target constant.
class ComplexPatternOperandMatcher : public OperandPredicateMatcher {
protected:
const OperandMatcher &Operand;
const Record &TheDef;
unsigned getAllocatedTemporariesBaseID() const;
public:
ComplexPatternOperandMatcher(const OperandMatcher &Operand,
const Record &TheDef)
: OperandPredicateMatcher(OPM_ComplexPattern), Operand(Operand),
TheDef(TheDef) {}
static bool classof(const OperandPredicateMatcher *P) {
return P->getKind() == OPM_ComplexPattern;
}
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
unsigned ID = getAllocatedTemporariesBaseID();
OS << "(Renderer" << ID << " = " << TheDef.getValueAsString("MatcherFn")
<< "(" << OperandExpr << "))";
}
unsigned countRendererFns() const override {
return 1;
}
};
/// Generates code to check that an operand is in a particular register bank.
class RegisterBankOperandMatcher : public OperandPredicateMatcher {
protected:
const CodeGenRegisterClass &RC;
public:
RegisterBankOperandMatcher(const CodeGenRegisterClass &RC)
: OperandPredicateMatcher(OPM_RegBank), RC(RC) {}
static bool classof(const OperandPredicateMatcher *P) {
return P->getKind() == OPM_RegBank;
}
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
OS << "(&RBI.getRegBankFromRegClass(" << RC.getQualifiedName()
<< "RegClass) == RBI.getRegBank(" << OperandExpr
<< ".getReg(), MRI, TRI))";
}
};
/// Generates code to check that an operand is a basic block.
class MBBOperandMatcher : public OperandPredicateMatcher {
public:
MBBOperandMatcher() : OperandPredicateMatcher(OPM_MBB) {}
static bool classof(const OperandPredicateMatcher *P) {
return P->getKind() == OPM_MBB;
}
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
OS << OperandExpr << ".isMBB()";
}
};
/// Generates code to check that an operand is a particular int.
class IntOperandMatcher : public OperandPredicateMatcher {
protected:
int64_t Value;
public:
IntOperandMatcher(int64_t Value)
: OperandPredicateMatcher(OPM_Int), Value(Value) {}
static bool classof(const OperandPredicateMatcher *P) {
return P->getKind() == OPM_Int;
}
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
OS << "isOperandImmEqual(" << OperandExpr << ", " << Value << ", MRI)";
}
};
/// Generates code to check that a set of predicates match for a particular
/// operand.
class OperandMatcher : public PredicateListMatcher<OperandPredicateMatcher> {
protected:
InstructionMatcher &Insn;
unsigned OpIdx;
std::string SymbolicName;
/// The index of the first temporary variable allocated to this operand. The
/// number of allocated temporaries can be found with
/// countRendererFns().
unsigned AllocatedTemporariesBaseID;
public:
OperandMatcher(InstructionMatcher &Insn, unsigned OpIdx,
const std::string &SymbolicName,
unsigned AllocatedTemporariesBaseID)
: Insn(Insn), OpIdx(OpIdx), SymbolicName(SymbolicName),
AllocatedTemporariesBaseID(AllocatedTemporariesBaseID) {}
bool hasSymbolicName() const { return !SymbolicName.empty(); }
const StringRef getSymbolicName() const { return SymbolicName; }
void setSymbolicName(StringRef Name) {
assert(SymbolicName.empty() && "Operand already has a symbolic name");
SymbolicName = Name;
}
unsigned getOperandIndex() const { return OpIdx; }
std::string getOperandExpr(StringRef InsnVarName) const {
return (InsnVarName + ".getOperand(" + llvm::to_string(OpIdx) + ")").str();
}
Optional<const OperandMatcher *>
getOptionalOperand(StringRef DesiredSymbolicName) const {
assert(!DesiredSymbolicName.empty() && "Cannot lookup unnamed operand");
if (DesiredSymbolicName == SymbolicName)
return this;
for (const auto &OP : predicates()) {
const auto &MaybeOperand = OP->getOptionalOperand(DesiredSymbolicName);
if (MaybeOperand.hasValue())
return MaybeOperand.getValue();
}
return None;
}
InstructionMatcher &getInstructionMatcher() const { return Insn; }
/// Emit C++ statements to capture instructions into local variables.
void emitCxxCaptureStmts(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const {
for (const auto &Predicate : predicates())
Predicate->emitCxxCaptureStmts(OS, Rule, OperandExpr);
}
/// Emit a C++ expression that tests whether the instruction named in
/// InsnVarName matches all the predicate and all the operands.
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef InsnVarName) const {
OS << "(/* ";
if (SymbolicName.empty())
OS << "Operand " << OpIdx;
else
OS << SymbolicName;
OS << " */ ";
emitCxxPredicateListExpr(OS, Rule, getOperandExpr(InsnVarName));
OS << ")";
}
/// Compare the priority of this object and B.
///
/// Returns true if this object is more important than B.
bool isHigherPriorityThan(const OperandMatcher &B) const {
// Operand matchers involving more predicates have higher priority.
if (predicates_size() > B.predicates_size())
return true;
if (predicates_size() < B.predicates_size())
return false;
// This assumes that predicates are added in a consistent order.
for (const auto &Predicate : zip(predicates(), B.predicates())) {
if (std::get<0>(Predicate)->isHigherPriorityThan(*std::get<1>(Predicate)))
return true;
if (std::get<1>(Predicate)->isHigherPriorityThan(*std::get<0>(Predicate)))
return false;
}
return false;
};
/// Report the maximum number of temporary operands needed by the operand
/// matcher.
unsigned countRendererFns() const {
return std::accumulate(
predicates().begin(), predicates().end(), 0,
[](unsigned A,
const std::unique_ptr<OperandPredicateMatcher> &Predicate) {
return A + Predicate->countRendererFns();
});
}
unsigned getAllocatedTemporariesBaseID() const {
return AllocatedTemporariesBaseID;
}
};
unsigned ComplexPatternOperandMatcher::getAllocatedTemporariesBaseID() const {
return Operand.getAllocatedTemporariesBaseID();
}
/// Generates code to check a predicate on an instruction.
///
/// Typical predicates include:
/// * The opcode of the instruction is a particular value.
/// * The nsw/nuw flag is/isn't set.
class InstructionPredicateMatcher {
protected:
/// This enum is used for RTTI and also defines the priority that is given to
/// the predicate when generating the matcher code. Kinds with higher priority
/// must be tested first.
enum PredicateKind {
IPM_Opcode,
};
PredicateKind Kind;
public:
InstructionPredicateMatcher(PredicateKind Kind) : Kind(Kind) {}
virtual ~InstructionPredicateMatcher() {}
PredicateKind getKind() const { return Kind; }
/// Emit a C++ expression that tests whether the instruction named in
/// InsnVarName matches the predicate.
virtual void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef InsnVarName) const = 0;
/// Compare the priority of this object and B.
///
/// Returns true if this object is more important than B.
virtual bool isHigherPriorityThan(const InstructionPredicateMatcher &B) const {
return Kind < B.Kind;
};
/// Report the maximum number of temporary operands needed by the predicate
/// matcher.
virtual unsigned countRendererFns() const { return 0; }
};
/// Generates code to check the opcode of an instruction.
class InstructionOpcodeMatcher : public InstructionPredicateMatcher {
protected:
const CodeGenInstruction *I;
public:
InstructionOpcodeMatcher(const CodeGenInstruction *I)
: InstructionPredicateMatcher(IPM_Opcode), I(I) {}
static bool classof(const InstructionPredicateMatcher *P) {
return P->getKind() == IPM_Opcode;
}
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef InsnVarName) const override {
OS << InsnVarName << ".getOpcode() == " << I->Namespace
<< "::" << I->TheDef->getName();
}
/// Compare the priority of this object and B.
///
/// Returns true if this object is more important than B.
bool isHigherPriorityThan(const InstructionPredicateMatcher &B) const override {
if (InstructionPredicateMatcher::isHigherPriorityThan(B))
return true;
if (B.InstructionPredicateMatcher::isHigherPriorityThan(*this))
return false;
// Prioritize opcodes for cosmetic reasons in the generated source. Although
// this is cosmetic at the moment, we may want to drive a similar ordering
// using instruction frequency information to improve compile time.
if (const InstructionOpcodeMatcher *BO =
dyn_cast<InstructionOpcodeMatcher>(&B))
return I->TheDef->getName() < BO->I->TheDef->getName();
return false;
};
};
/// Generates code to check that a set of predicates and operands match for a
/// particular instruction.
///
/// Typical predicates include:
/// * Has a specific opcode.
/// * Has an nsw/nuw flag or doesn't.
class InstructionMatcher
: public PredicateListMatcher<InstructionPredicateMatcher> {
protected:
typedef std::vector<std::unique_ptr<OperandMatcher>> OperandVec;
/// The operands to match. All rendered operands must be present even if the
/// condition is always true.
OperandVec Operands;
public:
/// Add an operand to the matcher.
OperandMatcher &addOperand(unsigned OpIdx, const std::string &SymbolicName,
unsigned AllocatedTemporariesBaseID) {
Operands.emplace_back(new OperandMatcher(*this, OpIdx, SymbolicName,
AllocatedTemporariesBaseID));
return *Operands.back();
}
OperandMatcher &getOperand(unsigned OpIdx) {
auto I = std::find_if(Operands.begin(), Operands.end(),
[&OpIdx](const std::unique_ptr<OperandMatcher> &X) {
return X->getOperandIndex() == OpIdx;
});
if (I != Operands.end())
return **I;
llvm_unreachable("Failed to lookup operand");
}
Optional<const OperandMatcher *>
getOptionalOperand(StringRef SymbolicName) const {
assert(!SymbolicName.empty() && "Cannot lookup unnamed operand");
for (const auto &Operand : Operands) {
const auto &OM = Operand->getOptionalOperand(SymbolicName);
if (OM.hasValue())
return OM.getValue();
}
return None;
}
const OperandMatcher &getOperand(StringRef SymbolicName) const {
Optional<const OperandMatcher *>OM = getOptionalOperand(SymbolicName);
if (OM.hasValue())
return *OM.getValue();
llvm_unreachable("Failed to lookup operand");
}
unsigned getNumOperands() const { return Operands.size(); }
OperandVec::iterator operands_begin() { return Operands.begin(); }
OperandVec::iterator operands_end() { return Operands.end(); }
iterator_range<OperandVec::iterator> operands() {
return make_range(operands_begin(), operands_end());
}
OperandVec::const_iterator operands_begin() const { return Operands.begin(); }
OperandVec::const_iterator operands_end() const { return Operands.end(); }
iterator_range<OperandVec::const_iterator> operands() const {
return make_range(operands_begin(), operands_end());
}
/// Emit C++ statements to check the shape of the match and capture
/// instructions into local variables.
void emitCxxCaptureStmts(raw_ostream &OS, RuleMatcher &Rule, StringRef Expr) {
OS << "if (" << Expr << ".getNumOperands() < " << getNumOperands() << ")\n"
<< " return false;\n";
for (const auto &Operand : Operands) {
Operand->emitCxxCaptureStmts(OS, Rule, Operand->getOperandExpr(Expr));
}
}
/// Emit a C++ expression that tests whether the instruction named in
/// InsnVarName matches all the predicates and all the operands.
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef InsnVarName) const {
emitCxxPredicateListExpr(OS, Rule, InsnVarName);
for (const auto &Operand : Operands) {
OS << " &&\n(";
Operand->emitCxxPredicateExpr(OS, Rule, InsnVarName);
OS << ")";
}
}
/// Compare the priority of this object and B.
///
/// Returns true if this object is more important than B.
bool isHigherPriorityThan(const InstructionMatcher &B) const {
// Instruction matchers involving more operands have higher priority.
if (Operands.size() > B.Operands.size())
return true;
if (Operands.size() < B.Operands.size())
return false;
for (const auto &Predicate : zip(predicates(), B.predicates())) {
if (std::get<0>(Predicate)->isHigherPriorityThan(*std::get<1>(Predicate)))
return true;
if (std::get<1>(Predicate)->isHigherPriorityThan(*std::get<0>(Predicate)))
return false;
}
for (const auto &Operand : zip(Operands, B.Operands)) {
if (std::get<0>(Operand)->isHigherPriorityThan(*std::get<1>(Operand)))
return true;
if (std::get<1>(Operand)->isHigherPriorityThan(*std::get<0>(Operand)))
return false;
}
return false;
};
/// Report the maximum number of temporary operands needed by the instruction
/// matcher.
unsigned countRendererFns() const {
return std::accumulate(predicates().begin(), predicates().end(), 0,
[](unsigned A,
const std::unique_ptr<InstructionPredicateMatcher>
&Predicate) {
return A + Predicate->countRendererFns();
}) +
std::accumulate(
Operands.begin(), Operands.end(), 0,
[](unsigned A, const std::unique_ptr<OperandMatcher> &Operand) {
return A + Operand->countRendererFns();
});
}
};
/// Generates code to check that the operand is a register defined by an
/// instruction that matches the given instruction matcher.
///
/// For example, the pattern:
/// (set $dst, (G_MUL (G_ADD $src1, $src2), $src3))
/// would use an InstructionOperandMatcher for operand 1 of the G_MUL to match
/// the:
/// (G_ADD $src1, $src2)
/// subpattern.
class InstructionOperandMatcher : public OperandPredicateMatcher {
protected:
std::unique_ptr<InstructionMatcher> InsnMatcher;
public:
InstructionOperandMatcher()
: OperandPredicateMatcher(OPM_Instruction),
InsnMatcher(new InstructionMatcher()) {}
static bool classof(const OperandPredicateMatcher *P) {
return P->getKind() == OPM_Instruction;
}
InstructionMatcher &getInsnMatcher() const { return *InsnMatcher; }
Optional<const OperandMatcher *>
getOptionalOperand(StringRef SymbolicName) const override {
assert(!SymbolicName.empty() && "Cannot lookup unnamed operand");
return InsnMatcher->getOptionalOperand(SymbolicName);
}
void emitCxxCaptureStmts(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
OS << "if (!" << OperandExpr + ".isReg())\n"
<< " return false;\n";
std::string InsnVarName = Rule.defineInsnVar(
OS, *InsnMatcher,
("*MRI.getVRegDef(" + OperandExpr + ".getReg())").str());
InsnMatcher->emitCxxCaptureStmts(OS, Rule, InsnVarName);
}
void emitCxxPredicateExpr(raw_ostream &OS, RuleMatcher &Rule,
StringRef OperandExpr) const override {
OperandExpr = Rule.getInsnVarName(*InsnMatcher);
OS << "(";
InsnMatcher->emitCxxPredicateExpr(OS, Rule, OperandExpr);
OS << ")\n";
}
};
//===- Actions ------------------------------------------------------------===//
class OperandRenderer {
public:
enum RendererKind { OR_Copy, OR_Imm, OR_Register, OR_ComplexPattern };
protected:
RendererKind Kind;
public:
OperandRenderer(RendererKind Kind) : Kind(Kind) {}
virtual ~OperandRenderer() {}
RendererKind getKind() const { return Kind; }
virtual void emitCxxRenderStmts(raw_ostream &OS, RuleMatcher &Rule) const = 0;
};
/// A CopyRenderer emits code to copy a single operand from an existing
/// instruction to the one being built.
class CopyRenderer : public OperandRenderer {
protected:
/// The matcher for the instruction that this operand is copied from.
/// This provides the facility for looking up an a operand by it's name so
/// that it can be used as a source for the instruction being built.
const InstructionMatcher &Matched;
/// The name of the operand.
const StringRef SymbolicName;
public:
CopyRenderer(const InstructionMatcher &Matched, StringRef SymbolicName)
: OperandRenderer(OR_Copy), Matched(Matched), SymbolicName(SymbolicName) {
}
static bool classof(const OperandRenderer *R) {
return R->getKind() == OR_Copy;
}
const StringRef getSymbolicName() const { return SymbolicName; }
void emitCxxRenderStmts(raw_ostream &OS, RuleMatcher &Rule) const override {
const OperandMatcher &Operand = Matched.getOperand(SymbolicName);
StringRef InsnVarName =
Rule.getInsnVarName(Operand.getInstructionMatcher());
std::string OperandExpr = Operand.getOperandExpr(InsnVarName);
OS << " MIB.add(" << OperandExpr << "/*" << SymbolicName << "*/);\n";
}
};
/// Adds a specific physical register to the instruction being built.
/// This is typically useful for WZR/XZR on AArch64.
class AddRegisterRenderer : public OperandRenderer {
protected:
const Record *RegisterDef;
public:
AddRegisterRenderer(const Record *RegisterDef)
: OperandRenderer(OR_Register), RegisterDef(RegisterDef) {}
static bool classof(const OperandRenderer *R) {
return R->getKind() == OR_Register;
}
void emitCxxRenderStmts(raw_ostream &OS, RuleMatcher &Rule) const override {
OS << " MIB.addReg(" << RegisterDef->getValueAsString("Namespace")
<< "::" << RegisterDef->getName() << ");\n";
}
};
/// Adds a specific immediate to the instruction being built.
class ImmRenderer : public OperandRenderer {
protected:
int64_t Imm;
public:
ImmRenderer(int64_t Imm)
: OperandRenderer(OR_Imm), Imm(Imm) {}
static bool classof(const OperandRenderer *R) {
return R->getKind() == OR_Imm;
}
void emitCxxRenderStmts(raw_ostream &OS, RuleMatcher &Rule) const override {
OS << " MIB.addImm(" << Imm << ");\n";
}
};
/// Adds operands by calling a renderer function supplied by the ComplexPattern
/// matcher function.
class RenderComplexPatternOperand : public OperandRenderer {
private:
const Record &TheDef;
/// The name of the operand.
const StringRef SymbolicName;
/// The renderer number. This must be unique within a rule since it's used to
/// identify a temporary variable to hold the renderer function.
unsigned RendererID;
unsigned getNumOperands() const {
return TheDef.getValueAsDag("Operands")->getNumArgs();
}
public:
RenderComplexPatternOperand(const Record &TheDef, StringRef SymbolicName,
unsigned RendererID)
: OperandRenderer(OR_ComplexPattern), TheDef(TheDef),
SymbolicName(SymbolicName), RendererID(RendererID) {}
static bool classof(const OperandRenderer *R) {
return R->getKind() == OR_ComplexPattern;
}
void emitCxxRenderStmts(raw_ostream &OS, RuleMatcher &Rule) const override {
OS << "Renderer" << RendererID << "(MIB);\n";
}
};
/// An action taken when all Matcher predicates succeeded for a parent rule.
///
/// Typical actions include:
/// * Changing the opcode of an instruction.
/// * Adding an operand to an instruction.
class MatchAction {
public:
virtual ~MatchAction() {}
/// Emit the C++ statements to implement the action.
///
/// \param RecycleVarName If given, it's an instruction to recycle. The
/// requirements on the instruction vary from action to
/// action.
virtual void emitCxxActionStmts(raw_ostream &OS, RuleMatcher &Rule,
StringRef RecycleVarName) const = 0;
};
/// Generates a comment describing the matched rule being acted upon.
class DebugCommentAction : public MatchAction {
private:
const PatternToMatch &P;
public:
DebugCommentAction(const PatternToMatch &P) : P(P) {}
void emitCxxActionStmts(raw_ostream &OS, RuleMatcher &Rule,
StringRef RecycleVarName) const override {
OS << "// " << *P.getSrcPattern() << " => " << *P.getDstPattern() << "\n";
}
};
/// Generates code to build an instruction or mutate an existing instruction
/// into the desired instruction when this is possible.
class BuildMIAction : public MatchAction {
private:
const CodeGenInstruction *I;
const InstructionMatcher &Matched;
std::vector<std::unique_ptr<OperandRenderer>> OperandRenderers;
/// True if the instruction can be built solely by mutating the opcode.
bool canMutate() const {
if (OperandRenderers.size() != Matched.getNumOperands())
return false;
for (const auto &Renderer : enumerate(OperandRenderers)) {
if (const auto *Copy = dyn_cast<CopyRenderer>(&*Renderer.value())) {
const OperandMatcher &OM = Matched.getOperand(Copy->getSymbolicName());
if (&Matched != &OM.getInstructionMatcher() ||
OM.getOperandIndex() != Renderer.index())
return false;
} else
return false;
}
return true;
}
public:
BuildMIAction(const CodeGenInstruction *I, const InstructionMatcher &Matched)
: I(I), Matched(Matched) {}
template <class Kind, class... Args>
Kind &addRenderer(Args&&... args) {
OperandRenderers.emplace_back(
llvm::make_unique<Kind>(std::forward<Args>(args)...));
return *static_cast<Kind *>(OperandRenderers.back().get());
}
void emitCxxActionStmts(raw_ostream &OS, RuleMatcher &Rule,
StringRef RecycleVarName) const override {
if (canMutate()) {
OS << " " << RecycleVarName << ".setDesc(TII.get(" << I->Namespace
<< "::" << I->TheDef->getName() << "));\n";
if (!I->ImplicitDefs.empty() || !I->ImplicitUses.empty()) {
OS << " auto MIB = MachineInstrBuilder(MF, &" << RecycleVarName
<< ");\n";
for (auto Def : I->ImplicitDefs) {
auto Namespace = Def->getValueAsString("Namespace");
OS << " MIB.addDef(" << Namespace << "::" << Def->getName()
<< ", RegState::Implicit);\n";
}
for (auto Use : I->ImplicitUses) {
auto Namespace = Use->getValueAsString("Namespace");
OS << " MIB.addUse(" << Namespace << "::" << Use->getName()
<< ", RegState::Implicit);\n";
}
}
OS << " MachineInstr &NewI = " << RecycleVarName << ";\n";
return;
}
// TODO: Simple permutation looks like it could be almost as common as
// mutation due to commutative operations.
OS << "MachineInstrBuilder MIB = BuildMI(*I.getParent(), I, "
"I.getDebugLoc(), TII.get("
<< I->Namespace << "::" << I->TheDef->getName() << "));\n";
for (const auto &Renderer : OperandRenderers)
Renderer->emitCxxRenderStmts(OS, Rule);
OS << " for (const auto *FromMI : ";
Rule.emitCxxCapturedInsnList(OS);
OS << ")\n";
OS << " for (const auto &MMO : FromMI->memoperands())\n";
OS << " MIB.addMemOperand(MMO);\n";
OS << " " << RecycleVarName << ".eraseFromParent();\n";
OS << " MachineInstr &NewI = *MIB;\n";
}
};
InstructionMatcher &RuleMatcher::addInstructionMatcher() {
Matchers.emplace_back(new InstructionMatcher());
return *Matchers.back();
}
void RuleMatcher::addRequiredFeature(Record *Feature) {
RequiredFeatures.push_back(Feature);
}
template <class Kind, class... Args>
Kind &RuleMatcher::addAction(Args &&... args) {
Actions.emplace_back(llvm::make_unique<Kind>(std::forward<Args>(args)...));
return *static_cast<Kind *>(Actions.back().get());
}
std::string RuleMatcher::defineInsnVar(raw_ostream &OS,
const InstructionMatcher &Matcher,
StringRef Value) {
std::string InsnVarName = "MI" + llvm::to_string(NextInsnVarID++);
OS << "MachineInstr &" << InsnVarName << " = " << Value << ";\n";
InsnVariableNames[&Matcher] = InsnVarName;
return InsnVarName;
}
StringRef RuleMatcher::getInsnVarName(const InstructionMatcher &InsnMatcher) const {
const auto &I = InsnVariableNames.find(&InsnMatcher);
if (I != InsnVariableNames.end())
return I->second;
llvm_unreachable("Matched Insn was not captured in a local variable");
}
/// Emit a C++ initializer_list containing references to every matched instruction.
void RuleMatcher::emitCxxCapturedInsnList(raw_ostream &OS) {
SmallVector<StringRef, 2> Names;
for (const auto &Pair : InsnVariableNames)
Names.push_back(Pair.second);
std::sort(Names.begin(), Names.end());
OS << "{";
for (const auto &Name : Names)
OS << "&" << Name << ", ";
OS << "}";
}
/// Emit C++ statements to check the shape of the match and capture
/// instructions into local variables.
void RuleMatcher::emitCxxCaptureStmts(raw_ostream &OS, StringRef Expr) {
assert(Matchers.size() == 1 && "Cannot handle multi-root matchers yet");
std::string InsnVarName = defineInsnVar(OS, *Matchers.front(), Expr);
Matchers.front()->emitCxxCaptureStmts(OS, *this, InsnVarName);
}
void RuleMatcher::emit(raw_ostream &OS,
SubtargetFeatureInfoMap SubtargetFeatures) {
if (Matchers.empty())
llvm_unreachable("Unexpected empty matcher!");
// The representation supports rules that require multiple roots such as:
// %ptr(p0) = ...
// %elt0(s32) = G_LOAD %ptr
// %1(p0) = G_ADD %ptr, 4
// %elt1(s32) = G_LOAD p0 %1
// which could be usefully folded into:
// %ptr(p0) = ...
// %elt0(s32), %elt1(s32) = TGT_LOAD_PAIR %ptr
// on some targets but we don't need to make use of that yet.
assert(Matchers.size() == 1 && "Cannot handle multi-root matchers yet");
OS << "if (";
OS << "[&]() {\n";
if (!RequiredFeatures.empty()) {
OS << " PredicateBitset ExpectedFeatures = {";
StringRef Separator = "";
for (const auto &Predicate : RequiredFeatures) {
const auto &I = SubtargetFeatures.find(Predicate);
assert(I != SubtargetFeatures.end() && "Didn't import predicate?");
OS << Separator << I->second.getEnumBitName();
Separator = ", ";
}
OS << "};\n";
OS << "if ((AvailableFeatures & ExpectedFeatures) != ExpectedFeatures)\n"
<< " return false;\n";
}
emitCxxCaptureStmts(OS, "I");
OS << " if (";
Matchers.front()->emitCxxPredicateExpr(OS, *this,
getInsnVarName(*Matchers.front()));
OS << ") {\n";
// We must also check if it's safe to fold the matched instructions.
if (InsnVariableNames.size() >= 2) {
for (const auto &Pair : InsnVariableNames) {
// Skip the root node since it isn't moving anywhere. Everything else is
// sinking to meet it.
if (Pair.first == Matchers.front().get())
continue;
// Reject the difficult cases until we have a more accurate check.
OS << " if (!isObviouslySafeToFold(" << Pair.second
<< ")) return false;\n";
// FIXME: Emit checks to determine it's _actually_ safe to fold and/or
// account for unsafe cases.
//
// Example:
// MI1--> %0 = ...
// %1 = ... %0
// MI0--> %2 = ... %0
// It's not safe to erase MI1. We currently handle this by not
// erasing %0 (even when it's dead).
//
// Example:
// MI1--> %0 = load volatile @a
// %1 = load volatile @a
// MI0--> %2 = ... %0
// It's not safe to sink %0's def past %1. We currently handle
// this by rejecting all loads.
//
// Example:
// MI1--> %0 = load @a
// %1 = store @a
// MI0--> %2 = ... %0
// It's not safe to sink %0's def past %1. We currently handle
// this by rejecting all loads.
//
// Example:
// G_CONDBR %cond, @BB1
// BB0:
// MI1--> %0 = load @a
// G_BR @BB1
// BB1:
// MI0--> %2 = ... %0
// It's not always safe to sink %0 across control flow. In this
// case it may introduce a memory fault. We currentl handle this
// by rejecting all loads.
}
}
for (const auto &MA : Actions) {
MA->emitCxxActionStmts(OS, *this, "I");
}
OS << " constrainSelectedInstRegOperands(NewI, TII, TRI, RBI);\n";
OS << " return true;\n";
OS << " }\n";
OS << " return false;\n";
OS << " }()) { return true; }\n\n";
}
bool RuleMatcher::isHigherPriorityThan(const RuleMatcher &B) const {
// Rules involving more match roots have higher priority.
if (Matchers.size() > B.Matchers.size())
return true;
if (Matchers.size() < B.Matchers.size())
return false;
for (const auto &Matcher : zip(Matchers, B.Matchers)) {
if (std::get<0>(Matcher)->isHigherPriorityThan(*std::get<1>(Matcher)))
return true;
if (std::get<1>(Matcher)->isHigherPriorityThan(*std::get<0>(Matcher)))
return false;
}
return false;
}
unsigned RuleMatcher::countRendererFns() const {
return std::accumulate(
Matchers.begin(), Matchers.end(), 0,
[](unsigned A, const std::unique_ptr<InstructionMatcher> &Matcher) {
return A + Matcher->countRendererFns();
});
}
//===- GlobalISelEmitter class --------------------------------------------===//
class GlobalISelEmitter {
public:
explicit GlobalISelEmitter(RecordKeeper &RK);
void run(raw_ostream &OS);
private:
const RecordKeeper &RK;
const CodeGenDAGPatterns CGP;
const CodeGenTarget &Target;
/// Keep track of the equivalence between SDNodes and Instruction.
/// This is defined using 'GINodeEquiv' in the target description.
DenseMap<Record *, const CodeGenInstruction *> NodeEquivs;
/// Keep track of the equivalence between ComplexPattern's and
/// GIComplexOperandMatcher. Map entries are specified by subclassing
/// GIComplexPatternEquiv.
DenseMap<const Record *, const Record *> ComplexPatternEquivs;
// Map of predicates to their subtarget features.
SubtargetFeatureInfoMap SubtargetFeatures;
void gatherNodeEquivs();
const CodeGenInstruction *findNodeEquiv(Record *N) const;
Error importRulePredicates(RuleMatcher &M, ArrayRef<Init *> Predicates);
Expected<InstructionMatcher &>
createAndImportSelDAGMatcher(InstructionMatcher &InsnMatcher,
const TreePatternNode *Src) const;
Error importChildMatcher(InstructionMatcher &InsnMatcher,
TreePatternNode *SrcChild, unsigned OpIdx,
unsigned &TempOpIdx) const;
Expected<BuildMIAction &> createAndImportInstructionRenderer(
RuleMatcher &M, const TreePatternNode *Dst,
const InstructionMatcher &InsnMatcher) const;
Error importExplicitUseRenderer(BuildMIAction &DstMIBuilder,
TreePatternNode *DstChild,
const InstructionMatcher &InsnMatcher) const;
Error
importImplicitDefRenderers(BuildMIAction &DstMIBuilder,
const std::vector<Record *> &ImplicitDefs) const;
/// Analyze pattern \p P, returning a matcher for it if possible.
/// Otherwise, return an Error explaining why we don't support it.
Expected<RuleMatcher> runOnPattern(const PatternToMatch &P);
void declareSubtargetFeature(Record *Predicate);
};
void GlobalISelEmitter::gatherNodeEquivs() {
assert(NodeEquivs.empty());
for (Record *Equiv : RK.getAllDerivedDefinitions("GINodeEquiv"))
NodeEquivs[Equiv->getValueAsDef("Node")] =
&Target.getInstruction(Equiv->getValueAsDef("I"));
assert(ComplexPatternEquivs.empty());
for (Record *Equiv : RK.getAllDerivedDefinitions("GIComplexPatternEquiv")) {
Record *SelDAGEquiv = Equiv->getValueAsDef("SelDAGEquivalent");
if (!SelDAGEquiv)
continue;
ComplexPatternEquivs[SelDAGEquiv] = Equiv;
}
}
const CodeGenInstruction *GlobalISelEmitter::findNodeEquiv(Record *N) const {
return NodeEquivs.lookup(N);
}
GlobalISelEmitter::GlobalISelEmitter(RecordKeeper &RK)
: RK(RK), CGP(RK), Target(CGP.getTargetInfo()) {}
//===- Emitter ------------------------------------------------------------===//
Error
GlobalISelEmitter::importRulePredicates(RuleMatcher &M,
ArrayRef<Init *> Predicates) {
for (const Init *Predicate : Predicates) {
const DefInit *PredicateDef = static_cast<const DefInit *>(Predicate);
declareSubtargetFeature(PredicateDef->getDef());
M.addRequiredFeature(PredicateDef->getDef());
}
return Error::success();
}
Expected<InstructionMatcher &> GlobalISelEmitter::createAndImportSelDAGMatcher(
InstructionMatcher &InsnMatcher, const TreePatternNode *Src) const {
// Start with the defined operands (i.e., the results of the root operator).
if (Src->getExtTypes().size() > 1)
return failedImport("Src pattern has multiple results");
auto SrcGIOrNull = findNodeEquiv(Src->getOperator());
if (!SrcGIOrNull)
return failedImport("Pattern operator lacks an equivalent Instruction" +
explainOperator(Src->getOperator()));
auto &SrcGI = *SrcGIOrNull;
// The operators look good: match the opcode and mutate it to the new one.
InsnMatcher.addPredicate<InstructionOpcodeMatcher>(&SrcGI);
unsigned OpIdx = 0;
unsigned TempOpIdx = 0;
for (const EEVT::TypeSet &Ty : Src->getExtTypes()) {
auto OpTyOrNone = MVTToLLT(Ty.getConcrete());
if (!OpTyOrNone)
return failedImport(
"Result of Src pattern operator has an unsupported type");
// Results don't have a name unless they are the root node. The caller will
// set the name if appropriate.
OperandMatcher &OM = InsnMatcher.addOperand(OpIdx++, "", TempOpIdx);
OM.addPredicate<LLTOperandMatcher>(*OpTyOrNone);
}
// Match the used operands (i.e. the children of the operator).
for (unsigned i = 0, e = Src->getNumChildren(); i != e; ++i) {
if (auto Error = importChildMatcher(InsnMatcher, Src->getChild(i), OpIdx++,
TempOpIdx))
return std::move(Error);
}
return InsnMatcher;
}
Error GlobalISelEmitter::importChildMatcher(InstructionMatcher &InsnMatcher,
TreePatternNode *SrcChild,
unsigned OpIdx,
unsigned &TempOpIdx) const {
OperandMatcher &OM =
InsnMatcher.addOperand(OpIdx, SrcChild->getName(), TempOpIdx);
if (SrcChild->hasAnyPredicate())
return failedImport("Src pattern child has predicate (" +
explainPredicates(SrcChild) + ")");
ArrayRef<EEVT::TypeSet> ChildTypes = SrcChild->getExtTypes();
if (ChildTypes.size() != 1)
return failedImport("Src pattern child has multiple results");
// Check MBB's before the type check since they are not a known type.
if (!SrcChild->isLeaf()) {
if (SrcChild->getOperator()->isSubClassOf("SDNode")) {
auto &ChildSDNI = CGP.getSDNodeInfo(SrcChild->getOperator());
if (ChildSDNI.getSDClassName() == "BasicBlockSDNode") {
OM.addPredicate<MBBOperandMatcher>();
return Error::success();
}
}
}
auto OpTyOrNone = MVTToLLT(ChildTypes.front().getConcrete());
if (!OpTyOrNone)
return failedImport("Src operand has an unsupported type");
OM.addPredicate<LLTOperandMatcher>(*OpTyOrNone);
// Check for nested instructions.
if (!SrcChild->isLeaf()) {
// Map the node to a gMIR instruction.
InstructionOperandMatcher &InsnOperand =
OM.addPredicate<InstructionOperandMatcher>();
auto InsnMatcherOrError =
createAndImportSelDAGMatcher(InsnOperand.getInsnMatcher(), SrcChild);
if (auto Error = InsnMatcherOrError.takeError())
return Error;
return Error::success();
}
// Check for constant immediates.
if (auto *ChildInt = dyn_cast<IntInit>(SrcChild->getLeafValue())) {
OM.addPredicate<IntOperandMatcher>(ChildInt->getValue());
return Error::success();
}
// Check for def's like register classes or ComplexPattern's.
if (auto *ChildDefInit = dyn_cast<DefInit>(SrcChild->getLeafValue())) {
auto *ChildRec = ChildDefInit->getDef();
// Check for register classes.
if (ChildRec->isSubClassOf("RegisterClass")) {
OM.addPredicate<RegisterBankOperandMatcher>(
Target.getRegisterClass(ChildRec));
return Error::success();
}
if (ChildRec->isSubClassOf("RegisterOperand")) {
OM.addPredicate<RegisterBankOperandMatcher>(
Target.getRegisterClass(ChildRec->getValueAsDef("RegClass")));
return Error::success();
}
// Check for ComplexPattern's.
if (ChildRec->isSubClassOf("ComplexPattern")) {
const auto &ComplexPattern = ComplexPatternEquivs.find(ChildRec);
if (ComplexPattern == ComplexPatternEquivs.end())
return failedImport("SelectionDAG ComplexPattern (" +
ChildRec->getName() + ") not mapped to GlobalISel");
OM.addPredicate<ComplexPatternOperandMatcher>(OM,
*ComplexPattern->second);
TempOpIdx++;
return Error::success();
}
if (ChildRec->isSubClassOf("ImmLeaf")) {
return failedImport(
"Src pattern child def is an unsupported tablegen class (ImmLeaf)");
}
return failedImport(
"Src pattern child def is an unsupported tablegen class");
}
return failedImport("Src pattern child is an unsupported kind");
}
Error GlobalISelEmitter::importExplicitUseRenderer(
BuildMIAction &DstMIBuilder, TreePatternNode *DstChild,
const InstructionMatcher &InsnMatcher) const {
// The only non-leaf child we accept is 'bb': it's an operator because
// BasicBlockSDNode isn't inline, but in MI it's just another operand.
if (!DstChild->isLeaf()) {
if (DstChild->getOperator()->isSubClassOf("SDNode")) {
auto &ChildSDNI = CGP.getSDNodeInfo(DstChild->getOperator());
if (ChildSDNI.getSDClassName() == "BasicBlockSDNode") {
DstMIBuilder.addRenderer<CopyRenderer>(InsnMatcher,
DstChild->getName());
return Error::success();
}
}
return failedImport("Dst pattern child isn't a leaf node or an MBB");
}
// Otherwise, we're looking for a bog-standard RegisterClass operand.
if (DstChild->hasAnyPredicate())
return failedImport("Dst pattern child has predicate (" +
explainPredicates(DstChild) + ")");
if (auto *ChildDefInit = dyn_cast<DefInit>(DstChild->getLeafValue())) {
auto *ChildRec = ChildDefInit->getDef();
ArrayRef<EEVT::TypeSet> ChildTypes = DstChild->getExtTypes();
if (ChildTypes.size() != 1)
return failedImport("Dst pattern child has multiple results");
auto OpTyOrNone = MVTToLLT(ChildTypes.front().getConcrete());
if (!OpTyOrNone)
return failedImport("Dst operand has an unsupported type");
if (ChildRec->isSubClassOf("Register")) {
DstMIBuilder.addRenderer<AddRegisterRenderer>(ChildRec);
return Error::success();
}
if (ChildRec->isSubClassOf("RegisterClass") ||
ChildRec->isSubClassOf("RegisterOperand")) {
DstMIBuilder.addRenderer<CopyRenderer>(InsnMatcher, DstChild->getName());
return Error::success();
}
if (ChildRec->isSubClassOf("ComplexPattern")) {
const auto &ComplexPattern = ComplexPatternEquivs.find(ChildRec);
if (ComplexPattern == ComplexPatternEquivs.end())
return failedImport(
"SelectionDAG ComplexPattern not mapped to GlobalISel");
const OperandMatcher &OM = InsnMatcher.getOperand(DstChild->getName());
DstMIBuilder.addRenderer<RenderComplexPatternOperand>(
*ComplexPattern->second, DstChild->getName(),
OM.getAllocatedTemporariesBaseID());
return Error::success();
}
if (ChildRec->isSubClassOf("SDNodeXForm"))
return failedImport("Dst pattern child def is an unsupported tablegen "
"class (SDNodeXForm)");
return failedImport(
"Dst pattern child def is an unsupported tablegen class");
}
return failedImport("Dst pattern child is an unsupported kind");
}
Expected<BuildMIAction &> GlobalISelEmitter::createAndImportInstructionRenderer(
RuleMatcher &M, const TreePatternNode *Dst,
const InstructionMatcher &InsnMatcher) const {
Record *DstOp = Dst->getOperator();
if (!DstOp->isSubClassOf("Instruction")) {
if (DstOp->isSubClassOf("ValueType"))
return failedImport(
"Pattern operator isn't an instruction (it's a ValueType)");
return failedImport("Pattern operator isn't an instruction");
}
auto &DstI = Target.getInstruction(DstOp);
auto &DstMIBuilder = M.addAction<BuildMIAction>(&DstI, InsnMatcher);
// Render the explicit defs.
for (unsigned I = 0; I < DstI.Operands.NumDefs; ++I) {
const auto &DstIOperand = DstI.Operands[I];
DstMIBuilder.addRenderer<CopyRenderer>(InsnMatcher, DstIOperand.Name);
}
// Figure out which operands need defaults inserted. Operands that subclass
// OperandWithDefaultOps are considered from left to right until we have
// enough operands to render the instruction.
SmallSet<unsigned, 2> DefaultOperands;
unsigned DstINumUses = DstI.Operands.size() - DstI.Operands.NumDefs;
unsigned NumDefaultOperands = 0;
for (unsigned I = 0; I < DstINumUses &&
DstINumUses > Dst->getNumChildren() + NumDefaultOperands;
++I) {
const auto &DstIOperand = DstI.Operands[DstI.Operands.NumDefs + I];
if (DstIOperand.Rec->isSubClassOf("OperandWithDefaultOps")) {
DefaultOperands.insert(I);
NumDefaultOperands +=
DstIOperand.Rec->getValueAsDag("DefaultOps")->getNumArgs();
}
}
if (DstINumUses > Dst->getNumChildren() + DefaultOperands.size())
return failedImport("Insufficient operands supplied and default ops "
"couldn't make up the shortfall");
if (DstINumUses < Dst->getNumChildren() + DefaultOperands.size())
return failedImport("Too many operands supplied");
// Render the explicit uses.
unsigned Child = 0;
for (unsigned I = 0; I != DstINumUses; ++I) {
// If we need to insert default ops here, then do so.
if (DefaultOperands.count(I)) {
const auto &DstIOperand = DstI.Operands[DstI.Operands.NumDefs + I];
DagInit *DefaultOps = DstIOperand.Rec->getValueAsDag("DefaultOps");
for (const auto *DefaultOp : DefaultOps->args()) {
// Look through ValueType operators.
if (const DagInit *DefaultDagOp = dyn_cast<DagInit>(DefaultOp)) {
if (const DefInit *DefaultDagOperator =
dyn_cast<DefInit>(DefaultDagOp->getOperator())) {
if (DefaultDagOperator->getDef()->isSubClassOf("ValueType"))
DefaultOp = DefaultDagOp->getArg(0);
}
}
if (const DefInit *DefaultDefOp = dyn_cast<DefInit>(DefaultOp)) {
DstMIBuilder.addRenderer<AddRegisterRenderer>(DefaultDefOp->getDef());
continue;
}
if (const IntInit *DefaultIntOp = dyn_cast<IntInit>(DefaultOp)) {
DstMIBuilder.addRenderer<ImmRenderer>(DefaultIntOp->getValue());
continue;
}
return failedImport("Could not add default op");
}
continue;
}
if (auto Error = importExplicitUseRenderer(
DstMIBuilder, Dst->getChild(Child), InsnMatcher))
return std::move(Error);
++Child;
}
return DstMIBuilder;
}
Error GlobalISelEmitter::importImplicitDefRenderers(
BuildMIAction &DstMIBuilder,
const std::vector<Record *> &ImplicitDefs) const {
if (!ImplicitDefs.empty())
return failedImport("Pattern defines a physical register");
return Error::success();
}
Expected<RuleMatcher> GlobalISelEmitter::runOnPattern(const PatternToMatch &P) {
// Keep track of the matchers and actions to emit.
RuleMatcher M;
M.addAction<DebugCommentAction>(P);
if (auto Error = importRulePredicates(M, P.getPredicates()->getValues()))
return std::move(Error);
// Next, analyze the pattern operators.
TreePatternNode *Src = P.getSrcPattern();
TreePatternNode *Dst = P.getDstPattern();
// If the root of either pattern isn't a simple operator, ignore it.
if (auto Err = isTrivialOperatorNode(Dst))
return failedImport("Dst pattern root isn't a trivial operator (" +
toString(std::move(Err)) + ")");
if (auto Err = isTrivialOperatorNode(Src))
return failedImport("Src pattern root isn't a trivial operator (" +
toString(std::move(Err)) + ")");
// Start with the defined operands (i.e., the results of the root operator).
Record *DstOp = Dst->getOperator();
if (!DstOp->isSubClassOf("Instruction"))
return failedImport("Pattern operator isn't an instruction");
auto &DstI = Target.getInstruction(DstOp);
if (DstI.Operands.NumDefs != Src->getExtTypes().size())
return failedImport("Src pattern results and dst MI defs are different (" +
to_string(Src->getExtTypes().size()) + " def(s) vs " +
to_string(DstI.Operands.NumDefs) + " def(s))");
InstructionMatcher &InsnMatcherTemp = M.addInstructionMatcher();
auto InsnMatcherOrError = createAndImportSelDAGMatcher(InsnMatcherTemp, Src);
if (auto Error = InsnMatcherOrError.takeError())
return std::move(Error);
InstructionMatcher &InsnMatcher = InsnMatcherOrError.get();
// The root of the match also has constraints on the register bank so that it
// matches the result instruction.
unsigned OpIdx = 0;
for (const EEVT::TypeSet &Ty : Src->getExtTypes()) {
(void)Ty;
const auto &DstIOperand = DstI.Operands[OpIdx];
Record *DstIOpRec = DstIOperand.Rec;
if (DstIOpRec->isSubClassOf("RegisterOperand"))
DstIOpRec = DstIOpRec->getValueAsDef("RegClass");
if (!DstIOpRec->isSubClassOf("RegisterClass"))
return failedImport("Dst MI def isn't a register class");
OperandMatcher &OM = InsnMatcher.getOperand(OpIdx);
OM.setSymbolicName(DstIOperand.Name);
OM.addPredicate<RegisterBankOperandMatcher>(
Target.getRegisterClass(DstIOpRec));
++OpIdx;
}
auto DstMIBuilderOrError =
createAndImportInstructionRenderer(M, Dst, InsnMatcher);
if (auto Error = DstMIBuilderOrError.takeError())
return std::move(Error);
BuildMIAction &DstMIBuilder = DstMIBuilderOrError.get();
// Render the implicit defs.
// These are only added to the root of the result.
if (auto Error = importImplicitDefRenderers(DstMIBuilder, P.getDstRegs()))
return std::move(Error);
// We're done with this pattern! It's eligible for GISel emission; return it.
++NumPatternImported;
return std::move(M);
}
void GlobalISelEmitter::run(raw_ostream &OS) {
// Track the GINodeEquiv definitions.
gatherNodeEquivs();
emitSourceFileHeader(("Global Instruction Selector for the " +
Target.getName() + " target").str(), OS);
std::vector<RuleMatcher> Rules;
// Look through the SelectionDAG patterns we found, possibly emitting some.
for (const PatternToMatch &Pat : CGP.ptms()) {
++NumPatternTotal;
auto MatcherOrErr = runOnPattern(Pat);
// The pattern analysis can fail, indicating an unsupported pattern.
// Report that if we've been asked to do so.
if (auto Err = MatcherOrErr.takeError()) {
if (WarnOnSkippedPatterns) {
PrintWarning(Pat.getSrcRecord()->getLoc(),
"Skipped pattern: " + toString(std::move(Err)));
} else {
consumeError(std::move(Err));
}
++NumPatternImportsSkipped;
continue;
}
Rules.push_back(std::move(MatcherOrErr.get()));
}
std::stable_sort(Rules.begin(), Rules.end(),
[&](const RuleMatcher &A, const RuleMatcher &B) {
if (A.isHigherPriorityThan(B)) {
assert(!B.isHigherPriorityThan(A) && "Cannot be more important "
"and less important at "
"the same time");
return true;
}
return false;
});
unsigned MaxTemporaries = 0;
for (const auto &Rule : Rules)
MaxTemporaries = std::max(MaxTemporaries, Rule.countRendererFns());
OS << "#ifdef GET_GLOBALISEL_PREDICATE_BITSET\n"
<< "const unsigned MAX_SUBTARGET_PREDICATES = " << SubtargetFeatures.size()
<< ";\n"
<< "using PredicateBitset = "
"llvm::PredicateBitsetImpl<MAX_SUBTARGET_PREDICATES>;\n"
<< "#endif // ifdef GET_GLOBALISEL_PREDICATE_BITSET\n\n";
OS << "#ifdef GET_GLOBALISEL_TEMPORARIES_DECL\n";
for (unsigned I = 0; I < MaxTemporaries; ++I)
OS << " mutable ComplexRendererFn Renderer" << I << ";\n";
OS << "#endif // ifdef GET_GLOBALISEL_TEMPORARIES_DECL\n\n";
OS << "#ifdef GET_GLOBALISEL_TEMPORARIES_INIT\n";
for (unsigned I = 0; I < MaxTemporaries; ++I)
OS << ", Renderer" << I << "(nullptr)\n";
OS << "#endif // ifdef GET_GLOBALISEL_TEMPORARIES_INIT\n\n";
OS << "#ifdef GET_GLOBALISEL_IMPL\n";
SubtargetFeatureInfo::emitSubtargetFeatureBitEnumeration(SubtargetFeatures,
OS);
// Separate subtarget features by how often they must be recomputed.
SubtargetFeatureInfoMap ModuleFeatures;
std::copy_if(SubtargetFeatures.begin(), SubtargetFeatures.end(),
std::inserter(ModuleFeatures, ModuleFeatures.end()),
[](const SubtargetFeatureInfoMap::value_type &X) {
return !X.second.mustRecomputePerFunction();
});
SubtargetFeatureInfoMap FunctionFeatures;
std::copy_if(SubtargetFeatures.begin(), SubtargetFeatures.end(),
std::inserter(FunctionFeatures, FunctionFeatures.end()),
[](const SubtargetFeatureInfoMap::value_type &X) {
return X.second.mustRecomputePerFunction();
});
SubtargetFeatureInfo::emitComputeAvailableFeatures(
Target.getName(), "InstructionSelector", "computeAvailableModuleFeatures",
ModuleFeatures, OS);
SubtargetFeatureInfo::emitComputeAvailableFeatures(
Target.getName(), "InstructionSelector",
"computeAvailableFunctionFeatures", FunctionFeatures, OS,
"const MachineFunction *MF");
OS << "bool " << Target.getName()
<< "InstructionSelector::selectImpl(MachineInstr &I) const {\n"
<< " MachineFunction &MF = *I.getParent()->getParent();\n"
<< " const MachineRegisterInfo &MRI = MF.getRegInfo();\n"
<< " // FIXME: This should be computed on a per-function basis rather than per-insn.\n"
<< " AvailableFunctionFeatures = computeAvailableFunctionFeatures(&STI, &MF);\n"
<< " const PredicateBitset AvailableFeatures = getAvailableFeatures();\n";
for (auto &Rule : Rules) {
Rule.emit(OS, SubtargetFeatures);
++NumPatternEmitted;
}
OS << " return false;\n"
<< "}\n"
<< "#endif // ifdef GET_GLOBALISEL_IMPL\n";
OS << "#ifdef GET_GLOBALISEL_PREDICATES_DECL\n"
<< "PredicateBitset AvailableModuleFeatures;\n"
<< "mutable PredicateBitset AvailableFunctionFeatures;\n"
<< "PredicateBitset getAvailableFeatures() const {\n"
<< " return AvailableModuleFeatures | AvailableFunctionFeatures;\n"
<< "}\n"
<< "PredicateBitset\n"
<< "computeAvailableModuleFeatures(const " << Target.getName()
<< "Subtarget *Subtarget) const;\n"
<< "PredicateBitset\n"
<< "computeAvailableFunctionFeatures(const " << Target.getName()
<< "Subtarget *Subtarget,\n"
<< " const MachineFunction *MF) const;\n"
<< "#endif // ifdef GET_GLOBALISEL_PREDICATES_DECL\n";
OS << "#ifdef GET_GLOBALISEL_PREDICATES_INIT\n"
<< "AvailableModuleFeatures(computeAvailableModuleFeatures(&STI)),\n"
<< "AvailableFunctionFeatures()\n"
<< "#endif // ifdef GET_GLOBALISEL_PREDICATES_INIT\n";
}
void GlobalISelEmitter::declareSubtargetFeature(Record *Predicate) {
if (SubtargetFeatures.count(Predicate) == 0)
SubtargetFeatures.emplace(
Predicate, SubtargetFeatureInfo(Predicate, SubtargetFeatures.size()));
}
} // end anonymous namespace
//===----------------------------------------------------------------------===//
namespace llvm {
void EmitGlobalISel(RecordKeeper &RK, raw_ostream &OS) {
GlobalISelEmitter(RK).run(OS);
}
} // End llvm namespace