Crate jit_core 

Core no_std types and encoding logic for AArch64 instruction synthesis.

This crate is the runtime heart of the project:

• [types] defines the structured operand model and generated spec metadata.
• [engine] implements variant selection, validation, and bitfield encoding.

Design goals:

• no_std compatibility (with alloc only where needed for diagnostics).
• deterministic, metadata-driven encoding (no handwritten opcode tables).
• strict error reporting for ambiguous or invalid operand forms.

Typical call paths:

• high-level: encode with canonical mnemonic + structured operands.
• low-level: encode_by_spec_operands when variant/spec is already known.
• dispatch assist: operand_shape_keys for precomputed shape-based routing.

Structs

BitFieldSpec

Field metadata for an instruction operand bitfield.

EncodingSpec

Encoding metadata for a single canonical instruction variant.

ExtendOperand

Extend modifier operand.

ImplicitField

Implicit default for one encoding field.

InstructionCode

AArch64 instruction with little-endian byte order.

MemoryOperand

Memory operand.

OperandConstraintSignature

One expected operand-form signature expressed as constraint kinds.

OperandShapeSignature

One provided operand-form signature expressed as concrete shape tags.

RegisterListOperand

Register-list operand.

RegisterOperand

Register operand with optional vector arrangement/lane decorations.

ShiftOperand

Shift modifier operand.

SplitImmediatePlanSpec

Precomputed split-immediate descriptor for one encoding variant.

SysRegOperand

System-register operand encoded as architectural parts.

Enums

AddressingMode

Addressing mode for memory operands.

AliasNoMatchHint

Structured alias mismatch hint.

ConditionCode

AArch64 condition code.

CoreNoMatchHint

Structured core mismatch hint.

EncodeError

Encoder errors.

ExtendKind

Extend kind.

MemoryAddressingConstraintSpec

Precomputed memory addressing constraint for one encoding variant.

MemoryOffset

Offset for memory operands.

Modifier

Modifier used in memory index expressions.

NoMatchingHint

Structured no-match hint for EncodeError::NoMatchingVariantHint.

Operand

Structured operand used by jit! and direct runtime encoding.

OperandConstraintKind

Per-slot operand constraint kind generated from AARCHMRS metadata.

OperandShapeTag

Operand-shape atom used in structured mismatch diagnostics.

PostIndexOffset

Post-index update component.

RegClass

Register family class used for mnemonic disambiguation.

ShiftKind

Shift kind.

SplitImmediateKindSpec

Split-immediate packing kind for one encoding variant.

VectorArrangement

Vector arrangement suffix.

Functions

encode

Selects a variant by mnemonic and typed operands and encodes it.

encode_by_spec

Encodes one instruction variant by spec.

encode_by_spec_operands

Returns EncodeError when operand count, kind, or ranges are invalid.

encode_candidates

Encodes one mnemonic using a generated shortlist of candidate variant indices.

operand_shape_keys

Computes packed operand-shape keys for all materialized flattenings of operands.

Type Aliases

OperandShapeKey

Packed key for one flattened operand-kind sequence.