Module field 

Field arithmetic modulo 2^255 - 19.

The compatibility backend uses FieldElement2625 and exposes serial and four-lane engines. Encoding, inversion, square-root chains, and parallel multiplication are implemented by the owning rhdl_ed25519_field crate.

Modules

parallel

Ten-lane, area-bounded field arithmetic engine.

Structs

FieldCodecEngine

Serial canonical encoder/decoder for field elements.

FieldCodecIn

Request accepted by FieldCodecEngine.

FieldCodecOut

Response from FieldCodecEngine.

FieldCodecRegs

Registered datapath state for FieldCodecEngine.

FieldElement2625

Field element stored as ten alternating 26/25-bit limbs in 32-bit lanes.

FieldMulEngine

Area-oriented serial field multiply/add/subtract engine.

FieldMulIn

Command accepted by serial or parallel field arithmetic engines.

FieldMulOut

Response from serial or parallel field arithmetic engines.

FieldMulRegs

Registered datapath state for FieldMulEngine.

FieldPowController

Controller that schedules fixed exponentiation chains on a shared multiplier.

FieldPowControllerIn

Combined request and shared-multiplier response for FieldPowController.

FieldPowControllerOut

External response and shared-multiplier command from FieldPowController.

FieldPowEngine

Self-contained exponentiation engine with an internal serial multiplier.

FieldPowIn

Exponentiation or multiply request.

FieldPowOut

Exponentiation-controller response.

FieldPowRegs

Registered temporaries for the fixed exponentiation chains.

ParallelFieldMulBank4

Four independent parallel field engines used by point-operation DAGs.

ParallelFieldMulEngine

One ten-output-lane field multiply/add/subtract engine.

Enums

FieldCodecState

Internal state of the canonical field codec.

FieldMulState

Internal state of the area-oriented serial field engine.

FieldPowState

Internal exponentiation-chain state.

Constants

FIELD_CODEC_DECODE

Decode bytes and report whether the input encoding was canonical.

FIELD_CODEC_ENCODE

Encode a field element to canonical bytes.

FIELD_OP_ADD

Add a + b and restore output limb bounds.

FIELD_OP_MUL

Multiply a * b mod p.

FIELD_OP_SUB

Subtract a - b mod p and restore output limb bounds.

FIELD_POW_INVERT

Compute multiplicative inverse base^(p-2).

FIELD_POW_MUL

Multiply base * other through the shared controller interface.

FIELD_POW_P58

Compute base^((p-5)/8) for point decoding.

FIELD_POW_SQRT

Compute the fixed square-root exponentiation used by point decoding.

Functions

field_add_2625_kernel

Add two loose radix-2^25.5 values limb by limb.

field_carry_reduce_2625_kernel

Propagate alternating 26/25-bit carries and fold bit 255 by factor 19.

field_codec_engine_kernel

Next-state/output kernel for FieldCodecEngine.

field_equal_kernel

Compare two field elements after canonical encoding.

field_from_bytes_kernel

Parse 32 little-endian bytes into radix-2^25.5 limbs.

field_is_negative_kernel

Return the parity bit of the canonical little-endian encoding.

field_is_zero_kernel

Return whether a field element is zero after canonical encoding.

field_minus_one_kernel

Synthesizable canonical representation of -1 mod p.

field_mul_engine_kernel

Next-state and output kernel for FieldMulEngine.

field_neg_2625_kernel

Negate a bounded field element modulo p.

field_one

Return the multiplicative identity as a host-side digital value.

field_one_kernel

Synthesizable constructor for the multiplicative identity.

field_pow_controller_kernel

Next-state/output kernel for FieldPowController.

field_pow_engine_kernel

Wires FieldPowController to its private FieldMulEngine.

field_reduce_wide_kernel

Reduce ten wide convolution accumulators to FieldElement2625.

field_sub_bias_2625_kernel

Subtract with a multiple-of-p bias that prevents negative limbs.

field_to_bytes_kernel

Carry, canonicalize, and encode a field element as 32 little-endian bytes.

field_zero

Return the additive identity as a host-side digital value.

field_zero_kernel

Synthesizable constructor for the additive identity.

lookup_select8_kernel

Constant-pattern selection from eight candidate field values.