Types

All values used in an LLVM module are explicitly typed. All types derive from a common base class Type. You can instantiate most of them directly. Once instantiated, a type should be considered immutable.

class llvmlite.ir.Type

The base class for all types. Never instantiate it directly. Types have the following methods in common:

  • as_pointer(addrspace=0)

    Return a PointerType pointing to this type. The optional addrspace integer allows you to choose a non-default address space—the meaning is platform dependent.

  • get_abi_size(target_data)

    Get the ABI size of this type, in bytes, according to the target_data—an llvmlite.binding.TargetData instance.

  • get_abi_alignment(target_data)

    Get the ABI alignment of this type, in bytes, according to the target_data—an llvmlite.binding.TargetData instance.

  • get_element_offset(target_data, position)

    Get the byte offset for the struct element at position, according to the target_data—an llvmlite.binding.TargetData instance.

    NOTE: get_abi_size(), get_abi_alignment(), and get_element_offset() call into the LLVM C++ API to get the requested information.

  • __call__(value)

    A convenience method to create a Constant of this type with the given value:

    >>> int32 = ir.IntType(32)
>>> c = int32(42)
>>> c
<ir.Constant type='i32' value=42>
>>> print(c)
i32 42

Atomic types

class llvmlite.ir.IntType(bits)

The type of integers. The Python integer bits specifies the bitwidth of the integers having this type.

width

The width in bits.

class llvmlite.ir.HalfType

The type of half-precision, floating-point, real numbers.

class llvmlite.ir.FloatType

The type of single-precision, floating-point, real numbers.

class llvmlite.ir.DoubleType

The type of double-precision, floating-point, real numbers.

class llvmlite.ir.VoidType

The class for void types. Used only as the return type of a function without a return value.

Pointer Types

llvmlite presently supports both Typed Pointers and Opaque Pointers. Typed Pointers are currently the default; Opaque Pointers will become the default in future, and support for Typed Pointers will be eventually be removed.

Note

Further details of the migration to Opaque Pointers are outlined in the section on Deprecation of Typed Pointers.

When Typed Pointers are enabled, the pointer type is represented using:

class llvmlite.ir.PointerType(pointee, addrspace=0)

The type of pointers to another type.

Pointer types expose the following attributes:

  • addrspace

    The pointer’s address space number. This optional integer allows you to choose a non-default address space—the meaning is platform dependent.

  • pointee

    The type pointed to.

Opaque pointers can be enabled by setting the environment variable:

LLVMLITE_ENABLE_OPAQUE_POINTERS=1

or by setting the opaque_pointers_enabled attribute after importing llvmlite, but prior to using any of its functionality. For example:

import llvmlite
llvmlite.opaque_pointers_enabled = True

# ... continue using llvmlite ...

When Opaque Pointers are enabled, the pointer type is represented using:

class llvmlite.ir.PointerType(addrspace=0)

The type of pointers.

Pointer types expose the following attribute:

  • addrspace

    The pointer’s address space number. This optional integer allows you to choose a non-default address space—the meaning is platform dependent.

Aggregate types

class llvmlite.ir.Aggregate

The base class for aggregate types. Never instantiate it directly. Aggregate types have the elements attribute in common.

elements

A tuple-like immutable sequence of element types for this aggregate type.

class llvmlite.ir.ArrayType(element, count)

The class for array types.

  • element is the type of every element.

  • count is a Python integer representing the number of elements.

class llvmlite.ir.VectorType(element, count)

The class for vector types.

  • element is the type of every element.

  • count is a Python integer representing the number of elements.

class llvmlite.ir.LiteralStructType(elements[, packed=False])

The class for literal struct types.

  • elements is a sequence of element types for each member of the structure.

  • packed controls whether to use packed layout.

class llvmlite.ir.IdentifiedStructType

The class for identified struct types. Identified structs are compared by name. It can be used to make opaque types.

Users should not create new instance directly. Use the Context.get_identified_type method instead.

An identified struct is created without a body (thus opaque). To define the struct body, use the .set_body method.

set_body(*elems)

Define the structure body with a sequence of element types.

Other types

class llvmlite.ir.FunctionType(return_type, args, var_arg=False)

The type of a function.

  • return_type is the return type of the function.

  • args is a sequence describing the types of argument to the function.

  • If var_arg is True, the function takes a variable number of additional arguments of unknown types after the explicit args.

    EXAMPLE:

    int32 = ir.IntType(32)
fnty = ir.FunctionType(int32, (ir.DoubleType(), ir.PointerType(int32)))

    An equivalent C declaration would be:

    typedef int32_t (*fnty)(double, int32_t *);
class llvmlite.ir.LabelType

The type for labels. You do not need to instantiate this type.

class llvmlite.ir.MetaDataType

The type for Metadata. You do not need to instantiate this type.

NOTE: This class was previously called “MetaData,” but it was renamed for clarity.