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Delete my old MDS code, now obsolete

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This commit is contained in:
Daniel Lubarov 2021-09-12 18:29:07 -07:00
parent a8d08aa153
commit 7ffeba3ae4
2 changed files with 0 additions and 124 deletions
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95
src/field/crandall_field.rs
View File

@ -17,90 +17,6 @@ use crate::field::inversion::try_inverse_u64;
/// EPSILON = 9 * 2**28 - 1
const EPSILON: u64 = 2415919103;
/// A precomputed 8*8 Cauchy matrix, generated with `Field::mds_8`.
const CAUCHY_MDS_8: [[CrandallField; 8]; 8] = [
[
CrandallField(16140901062381928449),
CrandallField(2635249153041947502),
CrandallField(3074457345215605419),
CrandallField(11068046442776179508),
CrandallField(13835058053470224385),
CrandallField(6148914690431210838),
CrandallField(9223372035646816257),
CrandallField(1),
],
[
CrandallField(2049638230143736946),
CrandallField(16140901062381928449),
CrandallField(2635249153041947502),
CrandallField(3074457345215605419),
CrandallField(11068046442776179508),
CrandallField(13835058053470224385),
CrandallField(6148914690431210838),
CrandallField(9223372035646816257),
],
[
CrandallField(5534023221388089754),
CrandallField(2049638230143736946),
CrandallField(16140901062381928449),
CrandallField(2635249153041947502),
CrandallField(3074457345215605419),
CrandallField(11068046442776179508),
CrandallField(13835058053470224385),
CrandallField(6148914690431210838),
],
[
CrandallField(16769767337539665921),
CrandallField(5534023221388089754),
CrandallField(2049638230143736946),
CrandallField(16140901062381928449),
CrandallField(2635249153041947502),
CrandallField(3074457345215605419),
CrandallField(11068046442776179508),
CrandallField(13835058053470224385),
],
[
CrandallField(10760600708254618966),
CrandallField(16769767337539665921),
CrandallField(5534023221388089754),
CrandallField(2049638230143736946),
CrandallField(16140901062381928449),
CrandallField(2635249153041947502),
CrandallField(3074457345215605419),
CrandallField(11068046442776179508),
],
[
CrandallField(5675921252705733081),
CrandallField(10760600708254618966),
CrandallField(16769767337539665921),
CrandallField(5534023221388089754),
CrandallField(2049638230143736946),
CrandallField(16140901062381928449),
CrandallField(2635249153041947502),
CrandallField(3074457345215605419),
],
[
CrandallField(1317624576520973751),
CrandallField(5675921252705733081),
CrandallField(10760600708254618966),
CrandallField(16769767337539665921),
CrandallField(5534023221388089754),
CrandallField(2049638230143736946),
CrandallField(16140901062381928449),
CrandallField(2635249153041947502),
],
[
CrandallField(15987178195121148178),
CrandallField(1317624576520973751),
CrandallField(5675921252705733081),
CrandallField(10760600708254618966),
CrandallField(16769767337539665921),
CrandallField(5534023221388089754),
CrandallField(2049638230143736946),
CrandallField(16140901062381928449),
],
];
/// A field designed for use with the Crandall reduction algorithm.
///
/// Its order is
@ -257,17 +173,6 @@ impl Field for CrandallField {
let x74 = x73 * x39;
x74
}
fn mds_8(vec: [Self; 8]) -> [Self; 8] {
let mut result = [Self::ZERO; 8];
for r in 0..8 {
for c in 0..8 {
let entry = CAUCHY_MDS_8[r][c];
result[r] += entry * vec[c];
}
}
result
}
}
impl PrimeField for CrandallField {

29
src/field/field_types.rs
View File

@ -280,35 +280,6 @@ pub trait Field:
}
}
/// Apply an MDS matrix to the given vector. Any MDS matrix can be used, as long as the same one
/// is used among calls with the same vector length.
///
/// Note that the default implementation is quite slow. If speed is important, this should be
/// overridden with a field-specific implementation which applies a precomputed MDS matrix.
fn mds(vec: Vec<Self>) -> Vec<Self> {
// We use a Cauchy matrix with x_r = n + r, y_c = c.
let n = vec.len();
let mut result = Vec::with_capacity(n);
for r in 0..n {
let mut sum = Self::ZERO;
for c in 0..n {
let x = Self::from_canonical_usize(n + r);
let y = Self::from_canonical_usize(c);
// This is the (r, c) entry of the Cauchy matrix.
let entry = (x - y).inverse();
sum += entry * vec[c];
}
result.push(sum);
}
result
}
/// Like `mds`, but specialized to n=8. For specific fields, this can be overridden with an
/// impl which applies a fast, precomputed 8x8 MDS matrix.
fn mds_8(vec: [Self; 8]) -> [Self; 8] {
Self::mds(vec.to_vec()).try_into().unwrap()
}
fn rand() -> Self {
Self::rand_from_rng(&mut rand::thread_rng())
}