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Merge pull request #6080 from Vurich/ethash

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Unroll loops in light_compute
This commit is contained in:
Robert Habermeier
2017-07-24 13:09:31 +02:00
committed by GitHub
parent e33f9c1d11 0fa9c93f6f
commit 079b24175c
4 changed files with 105 additions and 18 deletions
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83
ethash/src/compute.rs
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@@ -289,24 +289,55 @@ fn hash_compute(light: &Light, full_size: usize, header_hash: &H256, nonce: u64)
let num_full_pages = (full_size / page_size) as u32;
let cache: &[Node] = &light.cache; // deref once for better performance
for i in 0..(ETHASH_ACCESSES as u32) {
let index = fnv_hash(f_mix.get_unchecked(0).as_words().get_unchecked(0) ^ i, *mix.get_unchecked(0).as_words().get_unchecked((i as usize) % MIX_WORDS)) % num_full_pages;
for n in 0..MIX_NODES {
let tmp_node = calculate_dag_item(index * MIX_NODES as u32 + n as u32, cache);
for w in 0..NODE_WORDS {
*mix.get_unchecked_mut(n).as_words_mut().get_unchecked_mut(w) = fnv_hash(*mix.get_unchecked(n).as_words().get_unchecked(w), *tmp_node.as_words().get_unchecked(w));
debug_assert_eq!(ETHASH_ACCESSES, 64);
debug_assert_eq!(MIX_NODES, 2);
debug_assert_eq!(NODE_WORDS, 16);
unroll! {
// ETHASH_ACCESSES
for i_usize in 0..64 {
let i = i_usize as u32;
let index = fnv_hash(
f_mix.get_unchecked(0).as_words().get_unchecked(0) ^ i,
*mix.get_unchecked(0).as_words().get_unchecked(i as usize % MIX_WORDS)
) % num_full_pages;
unroll! {
// MIX_NODES
for n in 0..2 {
let tmp_node = calculate_dag_item(
index * MIX_NODES as u32 + n as u32,
cache,
);
unroll! {
// NODE_WORDS
for w in 0..16 {
*mix.get_unchecked_mut(n).as_words_mut().get_unchecked_mut(w) =
fnv_hash(
*mix.get_unchecked(n).as_words().get_unchecked(w),
*tmp_node.as_words().get_unchecked(w),
);
}
}
}
}
}
}
debug_assert_eq!(MIX_WORDS / 4, 8);
// compress mix
for i in 0..(MIX_WORDS / 4) {
let w = i * 4;
let mut reduction = *mix.get_unchecked(0).as_words().get_unchecked(w + 0);
reduction = reduction.wrapping_mul(FNV_PRIME) ^ *mix.get_unchecked(0).as_words().get_unchecked(w + 1);
reduction = reduction.wrapping_mul(FNV_PRIME) ^ *mix.get_unchecked(0).as_words().get_unchecked(w + 2);
reduction = reduction.wrapping_mul(FNV_PRIME) ^ *mix.get_unchecked(0).as_words().get_unchecked(w + 3);
*mix.get_unchecked_mut(0).as_words_mut().get_unchecked_mut(i) = reduction;
unroll! {
for i in 0..8 {
let w = i * 4;
let mut reduction = *mix.get_unchecked(0).as_words().get_unchecked(w + 0);
reduction = reduction.wrapping_mul(FNV_PRIME) ^ *mix.get_unchecked(0).as_words().get_unchecked(w + 1);
reduction = reduction.wrapping_mul(FNV_PRIME) ^ *mix.get_unchecked(0).as_words().get_unchecked(w + 2);
reduction = reduction.wrapping_mul(FNV_PRIME) ^ *mix.get_unchecked(0).as_words().get_unchecked(w + 3);
*mix.get_unchecked_mut(0).as_words_mut().get_unchecked_mut(i) = reduction;
}
}
let mut mix_hash = [0u8; 32];
@@ -331,13 +362,22 @@ fn calculate_dag_item(node_index: u32, cache: &[Node]) -> Node {
*ret.as_words_mut().get_unchecked_mut(0) ^= node_index;
sha3::sha3_512(ret.bytes.as_mut_ptr(), ret.bytes.len(), ret.bytes.as_ptr(), ret.bytes.len());
for i in 0..ETHASH_DATASET_PARENTS {
debug_assert_eq!(NODE_WORDS, 16);
for i in 0..ETHASH_DATASET_PARENTS as u32 {
let parent_index = fnv_hash(node_index ^ i, *ret.as_words().get_unchecked(i as usize % NODE_WORDS)) % num_parent_nodes as u32;
let parent = cache.get_unchecked(parent_index as usize);
for w in 0..NODE_WORDS {
*ret.as_words_mut().get_unchecked_mut(w) = fnv_hash(*ret.as_words().get_unchecked(w), *parent.as_words().get_unchecked(w));
unroll! {
for w in 0..16 {
*ret.as_words_mut().get_unchecked_mut(w) =
fnv_hash(
*ret.as_words().get_unchecked(w),
*parent.as_words().get_unchecked(w)
);
}
}
}
sha3::sha3_512(ret.bytes.as_mut_ptr(), ret.bytes.len(), ret.bytes.as_ptr(), ret.bytes.len());
ret
}
@@ -359,13 +399,20 @@ fn light_new<T: AsRef<Path>>(cache_dir: T, block_number: u64) -> Light {
sha3::sha3_512(nodes.get_unchecked_mut(i).bytes.as_mut_ptr(), NODE_BYTES, nodes.get_unchecked(i - 1).bytes.as_ptr(), NODE_BYTES);
}
debug_assert_eq!(NODE_WORDS, 16);
// This _should_ get unrolled by the compiler, since it's not using the loop variable.
for _ in 0..ETHASH_CACHE_ROUNDS {
for i in 0..num_nodes {
let idx = *nodes.get_unchecked_mut(i).as_words().get_unchecked(0) as usize % num_nodes;
let mut data = nodes.get_unchecked((num_nodes - 1 + i) % num_nodes).clone();
for w in 0..NODE_WORDS {
*data.as_words_mut().get_unchecked_mut(w) ^= *nodes.get_unchecked(idx).as_words().get_unchecked(w);
unroll! {
for w in 0..16 {
*data.as_words_mut().get_unchecked_mut(w) ^= *nodes.get_unchecked(idx).as_words().get_unchecked(w);
}
}
sha3_512(&data.bytes, &mut nodes.get_unchecked_mut(i).bytes);
}
}