Ranier Vilela писал 2021-08-13 14:12:
Em sex., 13 de ago. de 2021 às 07:15, Andres Freund
<and...@anarazel.de> escreveu:
Hi,
On 2021-08-13 12:44:17 +0300, Yura Sokolov wrote:
Andres Freund писал 2021-08-13 12:21:
Any chance you'd write a test for simplehash with such huge
amount of
values? It'd require a small bit of trickery to be practical. On
systems
with MAP_NORESERVE it should be feasible.
Which way C structures should be tested in postgres?
dynahash/simplhash - do they have any tests currently?
I'll do if hint is given.
We don't have a great way right now :(. I think the best is to have
a
SQL callable function that uses some API. See e.g. test_atomic_ops()
et
al in src/test/regress/regress.c
> static inline void
> -SH_COMPUTE_PARAMETERS(SH_TYPE * tb, uint32 newsize)
> +SH_COMPUTE_PARAMETERS(SH_TYPE * tb, uint64 newsize)
> {
> uint64 size;
>
> @@ -322,11 +322,7 @@ SH_COMPUTE_PARAMETERS(SH_TYPE * tb,
uint32
> newsize)
>
> /* now set size */
> tb->size = size;
> -
> - if (tb->size == SH_MAX_SIZE)
> - tb->sizemask = 0;
> - else
> - tb->sizemask = tb->size - 1;
> + tb->sizemask = (uint32)(size - 1);
ISTM using ~0 would be nicer here?
I don't think so.
To be rigid it should be `~(uint32)0`.
But I believe it doesn't differ from `tb->sizemask = (uint32)(size
- 1)`
that is landed with patch, therefore why `if` is needed?
Personally I find it more obvious to understand the intended
behaviour
with ~0 (i.e. all bits set) than with a width truncation.
https://godbolt.org/z/57WcjKqMj
The generated code is identical.
I believe, you mean https://godbolt.org/z/qWzE1ePTE
regards,
Ranier Vilela
