| // Copyright 2013 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_COMPILER_OPERATOR_H_ |
| #define V8_COMPILER_OPERATOR_H_ |
| |
| #include <ostream> // NOLINT(readability/streams) |
| |
| #include "src/base/compiler-specific.h" |
| #include "src/base/flags.h" |
| #include "src/base/functional.h" |
| #include "src/common/globals.h" |
| #include "src/handles/handles.h" |
| #include "src/zone/zone.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| // An operator represents description of the "computation" of a node in the |
| // compiler IR. A computation takes values (i.e. data) as input and produces |
| // zero or more values as output. The side-effects of a computation must be |
| // captured by additional control and data dependencies which are part of the |
| // IR graph. |
| // Operators are immutable and describe the statically-known parts of a |
| // computation. Thus they can be safely shared by many different nodes in the |
| // IR graph, or even globally between graphs. Operators can have "static |
| // parameters" which are compile-time constant parameters to the operator, such |
| // as the name for a named field access, the ID of a runtime function, etc. |
| // Static parameters are private to the operator and only semantically |
| // meaningful to the operator itself. |
| class V8_EXPORT_PRIVATE Operator : public NON_EXPORTED_BASE(ZoneObject) { |
| public: |
| using Opcode = uint16_t; |
| |
| // Properties inform the operator-independent optimizer about legal |
| // transformations for nodes that have this operator. |
| enum Property { |
| kNoProperties = 0, |
| kCommutative = 1 << 0, // OP(a, b) == OP(b, a) for all inputs. |
| kAssociative = 1 << 1, // OP(a, OP(b,c)) == OP(OP(a,b), c) for all inputs. |
| kIdempotent = 1 << 2, // OP(a); OP(a) == OP(a). |
| kNoRead = 1 << 3, // Has no scheduling dependency on Effects |
| kNoWrite = 1 << 4, // Does not modify any Effects and thereby |
| // create new scheduling dependencies. |
| kNoThrow = 1 << 5, // Can never generate an exception. |
| kNoDeopt = 1 << 6, // Can never generate an eager deoptimization exit. |
| kFoldable = kNoRead | kNoWrite, |
| kKontrol = kNoDeopt | kFoldable | kNoThrow, |
| kEliminatable = kNoDeopt | kNoWrite | kNoThrow, |
| kPure = kNoDeopt | kNoRead | kNoWrite | kNoThrow | kIdempotent |
| }; |
| |
| // List of all bits, for the visualizer. |
| #define OPERATOR_PROPERTY_LIST(V) \ |
| V(Commutative) \ |
| V(Associative) V(Idempotent) V(NoRead) V(NoWrite) V(NoThrow) V(NoDeopt) |
| |
| using Properties = base::Flags<Property, uint8_t>; |
| enum class PrintVerbosity { kVerbose, kSilent }; |
| |
| // Constructor. |
| Operator(Opcode opcode, Properties properties, const char* mnemonic, |
| size_t value_in, size_t effect_in, size_t control_in, |
| size_t value_out, size_t effect_out, size_t control_out); |
| |
| virtual ~Operator() = default; |
| |
| // A small integer unique to all instances of a particular kind of operator, |
| // useful for quick matching for specific kinds of operators. For fast access |
| // the opcode is stored directly in the operator object. |
| Opcode opcode() const { return opcode_; } |
| |
| // Returns a constant string representing the mnemonic of the operator, |
| // without the static parameters. Useful for debugging. |
| const char* mnemonic() const { return mnemonic_; } |
| |
| // Check if this operator equals another operator. Equivalent operators can |
| // be merged, and nodes with equivalent operators and equivalent inputs |
| // can be merged. |
| virtual bool Equals(const Operator* that) const { |
| return this->opcode() == that->opcode(); |
| } |
| |
| // Compute a hashcode to speed up equivalence-set checking. |
| // Equal operators should always have equal hashcodes, and unequal operators |
| // should have unequal hashcodes with high probability. |
| virtual size_t HashCode() const { return base::hash<Opcode>()(opcode()); } |
| |
| // Check whether this operator has the given property. |
| bool HasProperty(Property property) const { |
| return (properties() & property) == property; |
| } |
| |
| Properties properties() const { return properties_; } |
| |
| // TODO(titzer): convert return values here to size_t. |
| int ValueInputCount() const { return value_in_; } |
| int EffectInputCount() const { return effect_in_; } |
| int ControlInputCount() const { return control_in_; } |
| |
| int ValueOutputCount() const { return value_out_; } |
| int EffectOutputCount() const { return effect_out_; } |
| int ControlOutputCount() const { return control_out_; } |
| |
| static size_t ZeroIfEliminatable(Properties properties) { |
| return (properties & kEliminatable) == kEliminatable ? 0 : 1; |
| } |
| |
| static size_t ZeroIfNoThrow(Properties properties) { |
| return (properties & kNoThrow) == kNoThrow ? 0 : 2; |
| } |
| |
| static size_t ZeroIfPure(Properties properties) { |
| return (properties & kPure) == kPure ? 0 : 1; |
| } |
| |
| // TODO(titzer): API for input and output types, for typechecking graph. |
| |
| // Print the full operator into the given stream, including any |
| // static parameters. Useful for debugging and visualizing the IR. |
| void PrintTo(std::ostream& os, |
| PrintVerbosity verbose = PrintVerbosity::kVerbose) const { |
| // We cannot make PrintTo virtual, because default arguments to virtual |
| // methods are banned in the style guide. |
| return PrintToImpl(os, verbose); |
| } |
| |
| void PrintPropsTo(std::ostream& os) const; |
| |
| protected: |
| virtual void PrintToImpl(std::ostream& os, PrintVerbosity verbose) const; |
| |
| private: |
| const char* mnemonic_; |
| Opcode opcode_; |
| Properties properties_; |
| uint32_t value_in_; |
| uint32_t effect_in_; |
| uint32_t control_in_; |
| uint32_t value_out_; |
| uint8_t effect_out_; |
| uint32_t control_out_; |
| |
| DISALLOW_COPY_AND_ASSIGN(Operator); |
| }; |
| |
| DEFINE_OPERATORS_FOR_FLAGS(Operator::Properties) |
| |
| V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, |
| const Operator& op); |
| |
| // Default equality function for below Operator1<*> class. |
| template <typename T> |
| struct OpEqualTo : public std::equal_to<T> {}; |
| |
| |
| // Default hashing function for below Operator1<*> class. |
| template <typename T> |
| struct OpHash : public base::hash<T> {}; |
| |
| |
| // A templatized implementation of Operator that has one static parameter of |
| // type {T} with the proper default equality and hashing functions. |
| template <typename T, typename Pred = OpEqualTo<T>, typename Hash = OpHash<T>> |
| class Operator1 : public Operator { |
| public: |
| Operator1(Opcode opcode, Properties properties, const char* mnemonic, |
| size_t value_in, size_t effect_in, size_t control_in, |
| size_t value_out, size_t effect_out, size_t control_out, |
| T parameter, Pred const& pred = Pred(), Hash const& hash = Hash()) |
| : Operator(opcode, properties, mnemonic, value_in, effect_in, control_in, |
| value_out, effect_out, control_out), |
| parameter_(parameter), |
| pred_(pred), |
| hash_(hash) {} |
| |
| T const& parameter() const { return parameter_; } |
| |
| bool Equals(const Operator* other) const final { |
| if (opcode() != other->opcode()) return false; |
| const Operator1<T, Pred, Hash>* that = |
| reinterpret_cast<const Operator1<T, Pred, Hash>*>(other); |
| return this->pred_(this->parameter(), that->parameter()); |
| } |
| size_t HashCode() const final { |
| return base::hash_combine(this->opcode(), this->hash_(this->parameter())); |
| } |
| // For most parameter types, we have only a verbose way to print them, namely |
| // ostream << parameter. But for some types it is particularly useful to have |
| // a shorter way to print them for the node labels in Turbolizer. The |
| // following method can be overridden to provide a concise and a verbose |
| // printing of a parameter. |
| |
| virtual void PrintParameter(std::ostream& os, PrintVerbosity verbose) const { |
| os << "[" << parameter() << "]"; |
| } |
| |
| void PrintToImpl(std::ostream& os, PrintVerbosity verbose) const override { |
| os << mnemonic(); |
| PrintParameter(os, verbose); |
| } |
| |
| private: |
| T const parameter_; |
| Pred const pred_; |
| Hash const hash_; |
| }; |
| |
| |
| // Helper to extract parameters from Operator1<*> operator. |
| template <typename T> |
| inline T const& OpParameter(const Operator* op) { |
| return reinterpret_cast<const Operator1<T, OpEqualTo<T>, OpHash<T>>*>(op) |
| ->parameter(); |
| } |
| |
| |
| // NOTE: We have to be careful to use the right equal/hash functions below, for |
| // float/double we always use the ones operating on the bit level, for Handle<> |
| // we always use the ones operating on the location level. |
| template <> |
| struct OpEqualTo<float> : public base::bit_equal_to<float> {}; |
| template <> |
| struct OpHash<float> : public base::bit_hash<float> {}; |
| |
| template <> |
| struct OpEqualTo<double> : public base::bit_equal_to<double> {}; |
| template <> |
| struct OpHash<double> : public base::bit_hash<double> {}; |
| |
| template <> |
| struct OpEqualTo<Handle<HeapObject>> : public Handle<HeapObject>::equal_to {}; |
| template <> |
| struct OpHash<Handle<HeapObject>> : public Handle<HeapObject>::hash {}; |
| |
| template <> |
| struct OpEqualTo<Handle<String>> : public Handle<String>::equal_to {}; |
| template <> |
| struct OpHash<Handle<String>> : public Handle<String>::hash {}; |
| |
| template <> |
| struct OpEqualTo<Handle<ScopeInfo>> : public Handle<ScopeInfo>::equal_to {}; |
| template <> |
| struct OpHash<Handle<ScopeInfo>> : public Handle<ScopeInfo>::hash {}; |
| |
| } // namespace compiler |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_COMPILER_OPERATOR_H_ |