Type.h
#ifndef HALIDE_TYPE_H
#define HALIDE_TYPE_H
#include <stdint.h>
#include "runtime/HalideRuntime.h"
#include "Error.h"
#include "Util.h"
#include "Float16.h"
/** \file
* Defines halide types
*/
/** A set of types to represent a C++ function signature. This allows
* two things. First, proper prototypes can be provided for Halide
* generated functions, giving better compile time type
* checking. Second, C++ name mangling can be done to provide link
* time type checking for both Halide generated functions and calls
* from Halide to external functions.
*
* These are intended to be constexpr producable, but we don't depend
* on C++11 yet. In C++14, it is possible these will be replaced with
* introspection/reflection facilities.
*
* halide_handle_traits has to go outside the Halide namespace due to template
* resolution rules. TODO(zalman): Do all types need to be in global namespace?
*/
//@{
/** A structure to represent the (unscoped) name of a C++ composite type for use
* as a single argument (or return value) in a function signature.
*
* Currently does not support the restrict qualifier, references, or
* r-value references. These features cannot be used in extern
* function calls from Halide or in the generated function from
* Halide, but their applicability seems limited anyway.
*
* Although this is in the global namespace, it should be considered "Halide Internal"
* and subject to change; code outside Halide should avoid referencing it.
*/
struct halide_cplusplus_type_name {
/// An enum to indicate whether a C++ type is non-composite, a struct, class, or union
enum CPPTypeType {
Simple, ///< "int"
Struct, ///< "struct Foo"
Class, ///< "class Foo"
Union, ///< "union Foo"
Enum, ///< "enum Foo"
} cpp_type_type; // Note: order is reflected in map_to_name table in CPlusPlusMangle.cpp
std::string name;
halide_cplusplus_type_name(CPPTypeType cpp_type_type, const std::string &name)
: cpp_type_type(cpp_type_type), name(name) {
}
bool operator==(const halide_cplusplus_type_name &rhs) const {
return cpp_type_type == rhs.cpp_type_type &&
name == rhs.name;
}
bool operator!=(const halide_cplusplus_type_name &rhs) const {
return !(*this == rhs);
}
bool operator<(const halide_cplusplus_type_name &rhs) const {
return cpp_type_type < rhs.cpp_type_type ||
(cpp_type_type == rhs.cpp_type_type &&
name < rhs.name);
}
};
/** A structure to represent the fully scoped name of a C++ composite
* type for use in generating function signatures that use that type.
*
* This is intended to be a constexpr usable type, but we don't depend
* on C++11 yet. In C++14, it is possible this will be replaced with
* introspection/reflection facilities.
*
* Although this is in the global namespace, it should be considered "Halide Internal"
* and subject to change; code outside Halide should avoid referencing it.
*/
struct halide_handle_cplusplus_type {
halide_cplusplus_type_name inner_name;
std::vector<std::string> namespaces;
std::vector<halide_cplusplus_type_name> enclosing_types;
/// One set of modifiers on a type.
/// The const/volatile/restrict propertises are "inside" the pointer property.
enum Modifier : uint8_t {
Const = 1 << 0, ///< Bitmask flag for "const"
Volatile = 1 << 1, ///< Bitmask flag for "volatile"
Restrict = 1 << 2, ///< Bitmask flag for "restrict"
Pointer = 1 << 3, ///< Bitmask flag for a pointer "*"
};
/// Qualifiers and indirections on type. 0 is innermost.
std::vector<uint8_t> cpp_type_modifiers;
/// References are separate because they only occur at the outermost level.
/// No modifiers are needed for references as they are not allowed to apply
/// to the reference itself. (This isn't true for restrict, but that is a C++
/// extension anyway.) If modifiers are needed, the last entry in the above
/// array would be the modifers for the reference.
enum ReferenceType : uint8_t {
NotReference = 0,
LValueReference = 1, // "&"
RValueReference = 2, // "&&"
};
ReferenceType reference_type;
halide_handle_cplusplus_type(const halide_cplusplus_type_name &inner_name,
const std::vector<std::string> &namespaces = { },
const std::vector<halide_cplusplus_type_name> &enclosing_types = { },
const std::vector<uint8_t> &modifiers = { },
ReferenceType reference_type = NotReference)
: inner_name(inner_name),
namespaces(namespaces),
enclosing_types(enclosing_types),
cpp_type_modifiers(modifiers),
reference_type(reference_type) {}
template<typename T>
static const halide_handle_cplusplus_type make();
};
//@}
/** halide_c_type_to_name is a utility class used to provide a user-extensible
* way of naming Handle types.
*
* Although this is in the global namespace, it should be considered "Halide Internal"
* and subject to change; code outside Halide should avoid referencing it
* directly (use the HALIDE_DECLARE_EXTERN_xxx macros instead).
*/
template<typename T>
struct halide_c_type_to_name {
static constexpr bool known_type = false;
static halide_cplusplus_type_name name() {
return {halide_cplusplus_type_name::Simple, "void"};
}
};
#define HALIDE_DECLARE_EXTERN_TYPE(TypeType, Type) \
template<> struct halide_c_type_to_name<Type> { \
static constexpr bool known_type = true; \
static halide_cplusplus_type_name name() { \
return { halide_cplusplus_type_name::TypeType, #Type}; \
} \
}
#define HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(T) HALIDE_DECLARE_EXTERN_TYPE(Simple, T)
#define HALIDE_DECLARE_EXTERN_STRUCT_TYPE(T) HALIDE_DECLARE_EXTERN_TYPE(Struct, T)
#define HALIDE_DECLARE_EXTERN_CLASS_TYPE(T) HALIDE_DECLARE_EXTERN_TYPE(Class, T)
#define HALIDE_DECLARE_EXTERN_UNION_TYPE(T) HALIDE_DECLARE_EXTERN_TYPE(Union, T)
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(char);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(bool);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(int8_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(uint8_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(int16_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(uint16_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(int32_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(uint32_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(int64_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(uint64_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(Halide::float16_t);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(float);
HALIDE_DECLARE_EXTERN_SIMPLE_TYPE(double);
HALIDE_DECLARE_EXTERN_STRUCT_TYPE(buffer_t);
HALIDE_DECLARE_EXTERN_STRUCT_TYPE(halide_buffer_t);
HALIDE_DECLARE_EXTERN_STRUCT_TYPE(halide_dimension_t);
HALIDE_DECLARE_EXTERN_STRUCT_TYPE(halide_device_interface_t);
HALIDE_DECLARE_EXTERN_STRUCT_TYPE(halide_filter_metadata_t);
HALIDE_DECLARE_EXTERN_STRUCT_TYPE(halide_semaphore_t);
HALIDE_DECLARE_EXTERN_STRUCT_TYPE(halide_parallel_task_t);
// You can make arbitrary user-defined types be "Known" using the
// macro above. This is useful for making Param<> arguments for
// Generators type safe. e.g.,
//
// struct MyFunStruct { ... };
//
// ...
//
// HALIDE_DECLARE_EXTERN_STRUCT_TYPE(MyFunStruct);
//
// ...
//
// class MyGenerator : public Generator<MyGenerator> {
// Param<const MyFunStruct *> my_struct_ptr;
// ...
// };
template<typename T>
/*static*/ const halide_handle_cplusplus_type halide_handle_cplusplus_type::make() {
constexpr bool is_ptr = std::is_pointer<T>::value;
constexpr bool is_lvalue_reference = std::is_lvalue_reference<T>::value;
constexpr bool is_rvalue_reference = std::is_rvalue_reference<T>::value;
using TBase = typename std::remove_pointer<typename std::remove_reference<T>::type>::type;
constexpr bool is_const = std::is_const<TBase>::value;
constexpr bool is_volatile = std::is_volatile<TBase>::value;
constexpr uint8_t modifiers = static_cast<uint8_t>(
(is_ptr ? halide_handle_cplusplus_type::Pointer : 0) |
(is_const ? halide_handle_cplusplus_type::Const : 0) |
(is_volatile ? halide_handle_cplusplus_type::Volatile : 0)
);
constexpr halide_handle_cplusplus_type::ReferenceType ref_type =
is_lvalue_reference ? halide_handle_cplusplus_type::LValueReference
: (is_rvalue_reference ? halide_handle_cplusplus_type::RValueReference
: halide_handle_cplusplus_type::NotReference);
using TNonCVBase = typename std::remove_cv<TBase>::type;
constexpr bool known_type = halide_c_type_to_name<TNonCVBase>::known_type;
static_assert(!(!known_type && !is_ptr), "Unknown types must be pointers");
halide_handle_cplusplus_type info = {
halide_c_type_to_name<TNonCVBase>::name(),
{},
{},
{modifiers},
ref_type
};
// Pull off any namespaces
info.inner_name.name = Halide::Internal::extract_namespaces(info.inner_name.name, info.namespaces);
return info;
}
/** A type traits template to provide a halide_handle_cplusplus_type
* value from a C++ type.
*
* Note the type represented is implicitly a pointer.
*
* A NULL pointer of type halide_handle_traits represents "void *".
* This is chosen for compactness or representation as Type is a very
* widely used data structure.
*
* Although this is in the global namespace, it should be considered "Halide Internal"
* and subject to change; code outside Halide should avoid referencing it directly.
*/
template<typename T>
struct halide_handle_traits {
// This trait must return a pointer to a global structure. I.e. it should never be freed.
// A return value of nullptr here means "void *".
HALIDE_ALWAYS_INLINE static const halide_handle_cplusplus_type *type_info() {
if (std::is_pointer<T>::value ||
std::is_lvalue_reference<T>::value ||
std::is_rvalue_reference<T>::value) {
static const halide_handle_cplusplus_type the_info = halide_handle_cplusplus_type::make<T>();
return &the_info;
}
return nullptr;
}
};
namespace Halide {
struct Expr;
/** Types in the halide type system. They can be ints, unsigned ints,
* or floats of various bit-widths (the 'bits' field). They can also
* be vectors of the same (by setting the 'lanes' field to something
* larger than one). Front-end code shouldn't use vector
* types. Instead vectorize a function. */
struct Type {
private:
halide_type_t type;
public:
/** Aliases for halide_type_code_t values for legacy compatibility
* and to match the Halide internal C++ style. */
// @{
static const halide_type_code_t Int = halide_type_int;
static const halide_type_code_t UInt = halide_type_uint;
static const halide_type_code_t Float = halide_type_float;
static const halide_type_code_t Handle = halide_type_handle;
// @}
/** The number of bytes required to store a single scalar value of this type. Ignores vector lanes. */
int bytes() const {return (bits() + 7) / 8;}
// Default ctor initializes everything to predictable-but-unlikely values
Type() : type(Handle, 0, 0), handle_type(nullptr) {}
/** Construct a runtime representation of a Halide type from:
* code: The fundamental type from an enum.
* bits: The bit size of one element.
* lanes: The number of vector elements in the type. */
Type(halide_type_code_t code, int bits, int lanes, const halide_handle_cplusplus_type *handle_type = nullptr)
: type(code, (uint8_t)bits, (uint16_t)lanes), handle_type(handle_type) {
}
/** Trivial copy constructor. */
Type(const Type &that) = default;
/** Trivial copy assignment operator. */
Type &operator=(const Type &that) = default;
/** Type is a wrapper around halide_type_t with more methods for use
* inside the compiler. This simply constructs the wrapper around
* the runtime value. */
HALIDE_ALWAYS_INLINE
Type(const halide_type_t &that, const halide_handle_cplusplus_type *handle_type = nullptr)
: type(that), handle_type(handle_type) {}
/** Unwrap the runtime halide_type_t for use in runtime calls, etc.
* Representation is exactly equivalent. */
HALIDE_ALWAYS_INLINE
operator halide_type_t() const { return type; }
/** Return the underlying data type of an element as an enum value. */
HALIDE_ALWAYS_INLINE
halide_type_code_t code() const { return (halide_type_code_t)type.code; }
/** Return the bit size of a single element of this type. */
HALIDE_ALWAYS_INLINE
int bits() const { return type.bits; }
/** Return the number of vector elements in this type. */
HALIDE_ALWAYS_INLINE
int lanes() const { return type.lanes; }
/** Return Type with same number of bits and lanes, but new_code for a type code. */
Type with_code(halide_type_code_t new_code) const {
return Type(new_code, bits(), lanes(),
(new_code == code()) ? handle_type : nullptr);
}
/** Return Type with same type code and lanes, but new_bits for the number of bits. */
Type with_bits(int new_bits) const {
return Type(code(), new_bits, lanes(),
(new_bits == bits()) ? handle_type : nullptr);
}
/** Return Type with same type code and number of bits,
* but new_lanes for the number of vector lanes. */
Type with_lanes(int new_lanes) const {
return Type(code(), bits(), new_lanes, handle_type);
}
/** Type to be printed when declaring handles of this type. */
const halide_handle_cplusplus_type *handle_type;
/** Is this type boolean (represented as UInt(1))? */
HALIDE_ALWAYS_INLINE
bool is_bool() const {return code() == UInt && bits() == 1;}
/** Is this type a vector type? (lanes() != 1).
* TODO(abadams): Decide what to do for lanes() == 0. */
HALIDE_ALWAYS_INLINE
bool is_vector() const {return lanes() != 1;}
/** Is this type a scalar type? (lanes() == 1).
* TODO(abadams): Decide what to do for lanes() == 0. */
HALIDE_ALWAYS_INLINE
bool is_scalar() const {return lanes() == 1;}
/** Is this type a floating point type (float or double). */
HALIDE_ALWAYS_INLINE
bool is_float() const {return code() == Float;}
/** Is this type a signed integer type? */
HALIDE_ALWAYS_INLINE
bool is_int() const {return code() == Int;}
/** Is this type an unsigned integer type? */
HALIDE_ALWAYS_INLINE
bool is_uint() const {return code() == UInt;}
/** Is this type an opaque handle type (void *) */
HALIDE_ALWAYS_INLINE
bool is_handle() const {return code() == Handle;}
/** Check that the type name of two handles matches. */
bool same_handle_type(const Type &other) const;
/** Compare two types for equality */
bool operator==(const Type &other) const {
return type == other.type && (code() != Handle || same_handle_type(other));
}
/** Compare two types for inequality */
bool operator!=(const Type &other) const {
return type != other.type || (code() == Handle && !same_handle_type(other));
}
/** Compare ordering of two types so they can be used in certain containers and algorithms */
bool operator<(const Type &other) const {
if (type < other.type) return true;
if (code() == Handle) return handle_type < other.handle_type;
return false;
}
/** Produce the scalar type (that of a single element) of this vector type */
Type element_of() const {
return with_lanes(1);
}
/** Can this type represent all values of another type? */
bool can_represent(Type other) const;
/** Can this type represent a particular constant? */
// @{
bool can_represent(double x) const;
bool can_represent(int64_t x) const;
bool can_represent(uint64_t x) const;
// @}
/** Check if an integer constant value is the maximum or minimum
* representable value for this type. */
// @{
bool is_max(uint64_t) const;
bool is_max(int64_t) const;
bool is_min(uint64_t) const;
bool is_min(int64_t) const;
// @}
/** Return an expression which is the maximum value of this type.
* Returns infinity for types which can represent it. */
Expr max() const;
/** Return an expression which is the minimum value of this type.
* Returns -infinity for types which can represent it. */
Expr min() const;
};
/** Constructing a signed integer type */
inline Type Int(int bits, int lanes = 1) {
return Type(Type::Int, bits, lanes);
}
/** Constructing an unsigned integer type */
inline Type UInt(int bits, int lanes = 1) {
return Type(Type::UInt, bits, lanes);
}
/** Construct a floating-point type */
inline Type Float(int bits, int lanes = 1) {
return Type(Type::Float, bits, lanes);
}
/** Construct a boolean type */
inline Type Bool(int lanes = 1) {
return UInt(1, lanes);
}
/** Construct a handle type */
inline Type Handle(int lanes = 1, const halide_handle_cplusplus_type *handle_type = nullptr) {
return Type(Type::Handle, 64, lanes, handle_type);
}
/** Construct the halide equivalent of a C type */
template<typename T>
inline Type type_of() {
return Type(halide_type_of<T>(), halide_handle_traits<T>::type_info());
}
} // namespace Halide
#endif