From: Szabolcs Nagy <nsz@port70.net>
To: musl@lists.openwall.com
Subject: Re: ldso : dladdr support
Date: Fri, 24 Aug 2012 10:12:27 +0200 [thread overview]
Message-ID: <20120824081227.GG10731@port70.net> (raw)
In-Reply-To: <20120823222113.GT27715@brightrain.aerifal.cx>
* Rich Felker <dalias@aerifal.cx> [2012-08-23 18:21:13 -0400]:
> +static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
> +{
> + Sym *sym;
> + char *strings;
> + uint32_t *hashtab = dso->ghashtab;
> + uint32_t nbuckets = hashtab[0];
> + uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
> + uint32_t h2;
> + uint32_t *hashval;
> + uint32_t n = buckets[h1 % nbuckets];
> +
> + if (!n) return 0;
> +
> + strings = dso->strings;
> + sym = dso->syms + n;
> + hashval = buckets + nbuckets + (n - hashtab[1]);
> +
> + for (h1 |= 1; ; sym++) {
> + h2 = *hashval++;
> + if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name))
> + return sym;
> + if (h2 & 1) break;
> + }
heh, is this really the gnuhash lookup logic?
they drop a valuable low bit with h1 |= 1
high bits are less important for short
strings because of the *33 logic
(last 3-4 chars have no effect on the msb)
not that it matters much of course..
but seems silly design to me especially
when nbuckets is a power-of-2, then
highbits are not used for much and
could be used as flags for whatever
next prev parent reply other threads:[~2012-08-24 8:12 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-07 9:04 musl
2012-08-07 11:46 ` Szabolcs Nagy
2012-08-07 14:15 ` musl
2012-08-07 14:53 ` Szabolcs Nagy
2012-08-07 23:09 ` Rich Felker
2012-08-08 9:55 ` musl
2012-08-08 11:52 ` Szabolcs Nagy
2012-08-08 12:54 ` Rich Felker
2012-08-08 13:57 ` musl
2012-08-11 23:05 ` Rich Felker
2012-08-15 22:41 ` boris brezillon
2012-08-17 5:39 ` Rich Felker
2012-08-19 16:42 ` musl
2012-08-20 2:06 ` Rich Felker
2012-08-20 12:55 ` musl
2012-08-20 14:32 ` musl
2012-08-23 21:39 ` Rich Felker
2012-08-23 22:21 ` Rich Felker
2012-08-24 7:29 ` musl
2012-08-24 18:38 ` Rich Felker
2012-08-25 7:42 ` boris brezillon
2012-08-25 12:35 ` Rich Felker
2012-08-25 22:13 ` musl
2012-08-25 22:37 ` musl
2012-08-26 0:00 ` musl
2012-08-24 8:12 ` Szabolcs Nagy [this message]
2012-08-24 8:56 ` musl
2012-08-24 9:38 ` Szabolcs Nagy
2012-08-25 21:34 ` musl
2012-08-25 21:42 ` Rich Felker
2012-08-16 18:03 ` musl
2012-08-17 16:35 ` musl
2012-08-08 12:49 ` Rich Felker
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