Re: [PATCH v3 1/3] siphash: add cryptographically secure hashtable function

From: Jason A. Donenfeld
Date: Wed Dec 14 2016 - 18:34:39 EST


Hey Linus,

On Thu, Dec 15, 2016 at 12:30 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> No. The bug is talking about "words" in the first place.
>
> Depending on your background, a "word" can be generally be either 16
> bits or 32 bits (or, in some cases, 18 bits).
>
> In theory, a 64-bit entity can be a "word" too, but pretty much nobody
> uses that. Even architectures that started out with a 64-bit register
> size and never had any smaller historical baggage (eg alpha) tend to
> call 32-bit entities "words".
>
> So 16 bits can be a word, but some people/architectures will call it a
> "half-word".
>
> To make matters even more confusing, a "quadword" is generally always
> 64 bits, regardless of the size of "word".
>
> So please try to avoid the use of "word" entirely. It's too ambiguous,
> and it's not even helpful as a "size of the native register". It's
> almost purely random.
>
> For the kernel, we tend use
>
> - uX for types that have specific sizes (X being the number of bits)
>
> - "[unsigned] long" for native register size
>
> But never "word".

The voice of reason. Have a desired name for this function family?

siphash_3u64s
siphash_3u64
siphash_three_u64
siphash_3sixityfourbitintegers

Or does your reasonable dislike of "word" still allow for the use of
dword and qword, so that the current function names of:

siphash_3qwords
siphash_6dwords

are okay?

Jason