mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 21:10:07 +00:00
79 lines
2.3 KiB
C
79 lines
2.3 KiB
C
/* Compute hash alue for given string according to ELF standard.
|
|
Copyright (C) 1998-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#ifndef _DL_HASH_H
|
|
#define _DL_HASH_H 1
|
|
|
|
|
|
/* This is the hashing function specified by the ELF ABI. It is highly
|
|
optimized for the PII processors. Though it will run on i586 it
|
|
would be much slower than the generic C implementation. So don't
|
|
use it. */
|
|
static unsigned int
|
|
_dl_elf_hash (const char *name)
|
|
{
|
|
unsigned int result;
|
|
unsigned int temp0;
|
|
unsigned int temp1;
|
|
|
|
__asm__ __volatile__
|
|
("movzbl (%1),%2\n\t"
|
|
"testl %2, %2\n\t"
|
|
"jz 1f\n\t"
|
|
"movl %2, %0\n\t"
|
|
"movzbl 1(%1), %2\n\t"
|
|
"jecxz 1f\n\t"
|
|
"shll $4, %0\n\t"
|
|
"addl %2, %0\n\t"
|
|
"movzbl 2(%1), %2\n\t"
|
|
"jecxz 1f\n\t"
|
|
"shll $4, %0\n\t"
|
|
"addl %2, %0\n\t"
|
|
"movzbl 3(%1), %2\n\t"
|
|
"jecxz 1f\n\t"
|
|
"shll $4, %0\n\t"
|
|
"addl %2, %0\n\t"
|
|
"movzbl 4(%1), %2\n\t"
|
|
"jecxz 1f\n\t"
|
|
"shll $4, %0\n\t"
|
|
"addl $5, %1\n\t"
|
|
"addl %2, %0\n\t"
|
|
"movzbl (%1), %2\n\t"
|
|
"jecxz 1f\n"
|
|
"2:\t"
|
|
"shll $4, %0\n\t"
|
|
"movl $0xf0000000, %3\n\t"
|
|
"incl %1\n\t"
|
|
"addl %2, %0\n\t"
|
|
"andl %0, %3\n\t"
|
|
"andl $0x0fffffff, %0\n\t"
|
|
"shrl $24, %3\n\t"
|
|
"movzbl (%1), %2\n\t"
|
|
"xorl %3, %0\n\t"
|
|
"testl %2, %2\n\t"
|
|
"jnz 2b\n"
|
|
"1:\t"
|
|
: "=&r" (result), "=r" (name), "=&c" (temp0), "=&r" (temp1)
|
|
: "0" (0), "1" ((const unsigned char *) name));
|
|
|
|
return result;
|
|
}
|
|
|
|
#endif /* dl-hash.h */
|