llvmlite.ir
A module
consists mostly of values.
Undefined
An undefined value, mapping to LLVM's undef
.
The base class for all IR values.
A literal value.
- typ is the type of the represented value---a
~llvmlite.ir.Type
instance. - constant is the Python value to be represented.
Which Python types are allowed for constant depends on typ:
- All types accept
Undefined
and convert it to LLVM'sundef
. - All types accept
None
and convert it to LLVM'szeroinitializer
. IntType
accepts any Python integer or boolean.FloatType
andDoubleType
accept any Python real number.- Aggregate types---array and structure types---accept a sequence of Python values corresponding to the type's element types.
ArrayType
accepts a singlebytearray
instance to initialize the array from a string of bytes. This is useful for character constants.
literal_array(elements)
An alternate constructor for constant arrays.
- elements is a sequence of values,
Constant
or otherwise. - All elements must have the same type.
- Returns a constant array containing the elements, in order.
literal_struct(elements)
An alternate constructor for constant structs.
- elements is a sequence of values,
Constant
or otherwise. Returns a constant struct containing the elements in order.
bitcast(typ)
Convert this pointer constant to a constant of the given pointer type.
gep(indices)
Compute the address of the inner element given by the sequence of indices. The constant must have a pointer type.
inttoptr(typ)
Convert this integer constant to a constant of the given pointer type.
NOTE: You cannot define constant functions. Use a function declaration
instead.
One of a function's arguments. Arguments have the add_attribute
method.
add_attribute(attr)
Add an argument attribute to this argument. attr is a Python string.
A basic block
. Do not instantiate or mutate this type directly. Instead, call the helper methods on Function
and IRBuilder
.
Basic blocks have the following methods and attributes:
replace(old, new)
Replace the instruction old with the other instruction new in this block's list of instructions. All uses of old in the whole function are also patched. old and new are
Instruction
objects.function
The function this block is defined in.
is_terminated
Whether this block ends with a
terminator instruction <terminator>
.terminator
The block's
terminator instruction <terminator>
, if any. OtherwiseNone
.
A constant representing an address of a basic block.
Block address constants have the following attributes:
function
The function in which the basic block is defined.
basic_block
The basic block. Must be a part of
function
.
There are several kinds of metadata
values.
A string literal for use in metadata.
- module is the module that the metadata belongs to.
- value is a Python string.
A metadata node. To create an instance, call Module.add_metadata
.
A debug information descriptor, containing key-value pairs. To create an instance, call Module.add_debug_info
.
A debug information "token," representing a well-known enumeration value. value is the enumeration name.
EXAMPLE: 'DW_LANG_Python'
A named metadata node. To create an instance, call Module.add_named_metadata
. NamedMetaData
has the add
method:
add(md)
Append the given piece of metadata to the collection of operands referred to by the NamedMetaData
. md can be either a MetaDataString
or a MDValue
.
Global values are values accessible using a module-wide name.
The base class for global values. Global values have the following writable attributes:
linkage
A Python string describing the linkage behavior of the global value---for example, whether it is visible from other modules. The default is the empty string, meaning "external."
storage_class
A Python string describing the storage class of the global value.
- The default is the empty string, meaning "default."
- Other possible values include
dllimport
anddllexport
.
A global variable.
- module is where the variable is defined.
typ is the variable's type. It cannot be a function type. To declare a global function, use
Function
.The type of the returned Value is a pointer to typ. To read the contents of the variable, you need to
~IRBuilder.load
from the returned Value. To write to the variable, you need to~IRBuilder.store
to the returned Value.- name is the variable's name---a Python string.
- addrspace is an optional address space to store the variable in.
Global variables have the following writable attributes:
global_constant
- If
True
, the variable is declared a constant, meaning that its contents cannot be modified. - The default is
False
.
- If
unnamed_addr
- If
True
, the address of the variable is deemed insignificant, meaning that it is merged with other variables that have the same initializer. - The default is
False
.
- If
initializer
The variable's initialization value---probably a
Constant
of type typ. The default isNone
, meaning that the variable is uninitialized.align
An explicit alignment in bytes. The default is
None
, meaning that the default alignment for the variable's type is used.
A global function.
- module is where the function is defined.
- typ is the function's type---a
FunctionType
instance. - name is the function's name---a Python string.
If a global function has any basic blocks, it is a function definition
. Otherwise, it is a function declaration
.
Functions have the following methods and attributes:
append_basic_block(name='')
Append a
basic block
to this function's body.- If name is not empty, it names the block's entry
label
. - Returns a new
Block
.
- If name is not empty, it names the block's entry
insert_basic_block(before, name='')
Similar to
append_basic_block
, but inserts it before the basic block before in the function's list of basic blocks.set_metadata(name, node)
Add a function-specific metadata named name pointing to the given metadata node---an
MDValue
.args
The function's arguments as a tuple of
Argument
instances.attributes
A set of function attributes. Each optional attribute is a Python string. By default this is empty. Use the .add() method to add an attribute:
fnty = ir.FunctionType(ir.DoubleType(), (ir.DoubleType(),)) fn = Function(module, fnty, "sqrt") fn.attributes.add("alwaysinline")
calling_convention
The function's calling convention---a Python string. The default is the empty string.
is_declaration
Indicates whether the global function is a declaration or a definition.
- If
True
, it is a declaration. - If
False
, it is a definition.
- If
Every instruction
is also a value:
- It has a name---the recipient's name.
- It has a well-defined type.
- It can be used as an operand in other instructions or in literals.
Usually, you should not instantiate instruction types directly. Use the helper methods on the IRBuilder
class.
The base class for all instructions. Instructions have the following method and attributes:
set_metadata(name, node)
Add an instruction-specific metadata name pointing to the given metadata node---an
MDValue
.replace_usage(old, new)
Replace the operand old with the other instruction new.
function
The function that contains this instruction.
module
The module that defines this instruction's function.
The class of instructions for which we can specify the probabilities of different outcomes---for example, a switch or a conditional branch. Predictable instructions have the set_weights
method.
set_weights(weights)
Set the weights of the instruction's possible outcomes. weights is a sequence of positive integers, each corresponding to a different outcome and specifying its relative probability compared to other outcomes. The greater the number, the likelier the outcome.
A switch instruction. Switch instructions have the add_case
method.
add_case(val, block)
Add a case to the switch instruction.
- val should be a
Constant
or a Python value compatible with the switch instruction's operand type. - block is a
Block
to jump to if val and the switch operand compare equal.
An indirect branch instruction. Indirect branch instructions have the add_destination
method.
add_destination(value, block)
Add an outgoing edge. The indirect branch instruction must refer to every basic block it can transfer control to.
A phi instruction. Phi instructions have the add_incoming
method.
add_incoming(value, block)
Add an incoming edge. Whenever transfer is controlled from block---a Block
---the phi instruction takes the given value.
A landing pad. Landing pads have the add_clause
method:
add_clause(value, block)
Add a catch or filter clause. Create catch clauses using CatchClause
and filter clauses using FilterClause
.
Landing pads have the following classes associated with them.
A catch clause. Instructs the personality function to compare the in-flight exception typeinfo with value, which should have type IntType(8).as_pointer().as_pointer().
A filter clause. Instructs the personality function to check inclusion of the the in-flight exception typeinfo in value, which should have type ArrayType(IntType(8).as_pointer().as_pointer(), ...).