Subject: Re: [PATCH 0/7] RFC: Accelerate xdiff and begin its rustification

From: Junio C Hamano <[email-masked]>
Date: Mon, 21 Jul 2025 11:33:52 -0700

Phillip Wood <[email-masked]> writes:

> ... by 15%. Just over half of that seems to come from hoisting the
> check for whitespace flags in xdl_hash_record() out of the loop
> in xdl_prepare_ctx() and the rest comes from the change in hash
> function.

The first half of that alone is interesting enough ;-).

> As I understand it the hash is implemented using SIMD
> compiler intrinsics and the rust implementation is basically a
> copy of the C code in libxxhash. I wonder how well xxhash performs
> compared to our existing hash on platforms without an optimized
> implementation.

Yeah, that indeed is worth investigating.

Thanks.