sword_smith    2025-02-27 👍 1 👎

I would ignore that comment in the README if I were you.

Here’s what I would do:

1. Install Futhark
2. Install CUDA if you haven’t already
3. clone this repo: https://github.com/Holindauer/ruthark
4. Write a fast_kernel_mast_hash implementation in Futhark (see below).
5. Write a benchmark of fast_kernel_mast_hash (see below).
6. See if you can get a speedup compared to what you can do on your CPU.

There’s no point in proceeding, I think, if you can’t get the GPU hasher to run faster than on your CPU. Unless you have a GPU cluster, I guess.

fast_kernel_mast_hash in Futhark

def fast_kernel_mast_hash (kernel_auth_path: [2]Digest) (header_auth_path: [3] Digest) (nonce: Digest) : Digest =
  let header_mast_hash = Tip5.hash_pair (Tip5.hash_varlen nonce.0) header_auth_path[0]
  let header_mast_hash = Tip5.hash_pair header_mast_hash header_auth_path[1]
  let header_mast_hash = Tip5.hash_pair header_auth_path[2] header_mast_hash

  in Tip5.hash_pair
    (Tip5.hash_pair
      (Tip5.hash_varlen header_mast_hash.0)
      kernel_auth_path[0])
    kernel_auth_path[1]

Benchmark of fast_kernel_mast_hash in Futhark

-- ==
-- entry: fast_kernel_mast_hash_bench
-- random input { [1000][5]u64 [2][5]u64 [3][5]u64 }
-- random input { [1000000][5]u64 [2][5]u64 [3][5]u64 }
entry fast_kernel_mast_hash_bench ( nonces: [][Digest.DIGEST_LENGTH]u64 ) (kernel_auth_path: [2][Digest.DIGEST_LENGTH]u64) (header_auth_path: [3][Digest.DIGEST_LENGTH]u64) =
   let u64s_to_digest (bfes: [Digest.DIGEST_LENGTH]u64): Digest = {0 = map (\x -> BFieldElement.new x) bfes}
   let bfe_to_u64 (bfe: BFieldElement): u64 = BFieldElement.value(bfe)
   let nonces = map u64s_to_digest nonces
   let kap = map u64s_to_digest kernel_auth_path
   let hap = map u64s_to_digest header_auth_path
   in map (\x -> fast_kernel_mast_hash kap hap x) nonces

Run benchmark of fast_kernel_mast_hash on a CUDA backend: futhark bench --backend=cuda fut-src/Tip5.fut

Compile a binary, with the Futhark compiler, that compiles a CUDA program. futhark cuda fut-src/Tip5.fut -o Tip5.