Module bytecode

Expand description

Implement python as a virtual machine with bytecode. This module implements bytecode structure.

Modules§

Arg
Arguments: Argument structure
BasicBag
CodeFlags
CodeObject: Primary container of a single code object. Each python function has a code object. Also a module has a code object.
CodeUnit
CodeUnits
Constants
ExceptionTableEntry: Exception table entry for zero-cost exception handling Format: (start, size, target, depth<<1|lasti)
Label
LoadAttr
LoadSuperAttr
MakeFunctionFlags
OpArg: Full 32-bit op_arg, including any possible ExtendedArg extension.
OpArgByte: Opcode argument that may be extended by a prior ExtendedArg.
OpArgState
StackEffect: What effect the instruction has on the stack.
UnpackExArgs

AnyInstruction
BinaryOperator: The possible Binary operators
BorrowedConstant: A borrowed Constant
BuildSliceArgCount: Specifies if a slice is built with either 2 or 3 arguments.
CommonConstant: Common constants for LOAD_COMMON_CONSTANT opcode. pycore_opcode_utils.h CONSTANT_*
ComparisonOperator: COMPARE_OP arg is (cmp_index << 5) | mask. Only the upper 3 bits identify the comparison; the lower 5 bits are an inline cache mask for adaptive specialization.
ConstantData: A Constant (which usually encapsulates data within it)
ConvertValueOparg: Oparg values for Instruction::ConvertValue.
Instruction: A Single bytecode instruction that are executed by the VM.
IntrinsicFunction1: Intrinsic function for CALL_INTRINSIC_1
IntrinsicFunction2: Intrinsic function for CALL_INTRINSIC_2
Invert: Whether or not to invert the operation.
MakeFunctionFlag: SET_FUNCTION_ATTRIBUTE flags. Bitmask: Defaults=0x01, KwOnly=0x02, Annotations=0x04, Closure=0x08, TypeParams=0x10, Annotate=0x20. Stored as bit position (0-5) by bitflag! macro.
PseudoInstruction: Instructions used by the compiler. They are not executed by the VM.
PyCodeLocationInfoKind: CPython 3.11+ linetable location info codes
RaiseKind: The kind of Raise that occurred.
SpecialMethod: Special method for LOAD_SPECIAL opcode (context managers).

ADAPTIVE_COOLDOWN_VALUE: Adaptive specialization: cooldown counter after a successful specialization.
ADAPTIVE_WARMUP_VALUE: Adaptive specialization: number of executions before attempting specialization.
CO_FAST_CELL
CO_FAST_FREE
CO_FAST_HIDDEN: Per-slot kind flags for localsplus (co_localspluskinds).
CO_FAST_LOCAL
JUMP_BACKWARD_INITIAL_VALUE: Initial JUMP_BACKWARD counter bits (value/backoff = 4095/12).

adaptive_counter_backoff: Reset adaptive counter with exponential backoff.
adaptive_counter_bits: Encode an adaptive counter as (value << 4) | backoff.
adaptive_counter_triggers: True when the adaptive counter should trigger specialization.
advance_adaptive_counter: Decrement adaptive counter by one countdown step.
build_no_location_mask: Parse linetable to build a boolean mask indicating which code units have NO_LOCATION (line == -1). Returns a Vec of length num_units.
decode_exception_table: Decode all exception table entries.
encode_exception_table: Encode exception table entries. Uses 6-bit varint encoding with start marker (MSB) and continuation bit.
find_exception_handler: Find exception handler for given instruction offset.