gcc/libiberty/bsearch.c

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/*
* Copyright (c) 1990 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. [rescinded 22 July 1999]
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
@deftypefn Supplemental void* bsearch (const void *@var{key}, @
const void *@var{base}, size_t @var{nmemb}, size_t @var{size}, @
int (*@var{compar})(const void *, const void *))
Performs a search over an array of @var{nmemb} elements pointed to by
@var{base} for a member that matches the object pointed to by @var{key}.
The size of each member is specified by @var{size}. The array contents
should be sorted in ascending order according to the @var{compar}
comparison function. This routine should take two arguments pointing to
the @var{key} and to an array member, in that order, and should return an
integer less than, equal to, or greater than zero if the @var{key} object
is respectively less than, matching, or greater than the array member.
@end deftypefn
*/
#include "config.h"
#include "ansidecl.h"
#include <sys/types.h> /* size_t */
#include <stdio.h>
/*
* Perform a binary search.
*
* The code below is a bit sneaky. After a comparison fails, we
* divide the work in half by moving either left or right. If lim
* is odd, moving left simply involves halving lim: e.g., when lim
* is 5 we look at item 2, so we change lim to 2 so that we will
* look at items 0 & 1. If lim is even, the same applies. If lim
* is odd, moving right again involes halving lim, this time moving
* the base up one item past p: e.g., when lim is 5 we change base
* to item 3 and make lim 2 so that we will look at items 3 and 4.
* If lim is even, however, we have to shrink it by one before
* halving: e.g., when lim is 4, we still looked at item 2, so we
* have to make lim 3, then halve, obtaining 1, so that we will only
* look at item 3.
*/
void *
bsearch (const void *key, const void *base0,
size_t nmemb, size_t size,
int (*compar)(const void *, const void *))
{
const char *base = (const char *) base0;
int lim, cmp;
const void *p;
for (lim = nmemb; lim != 0; lim >>= 1) {
p = base + (lim >> 1) * size;
cmp = (*compar)(key, p);
if (cmp == 0)
return (void *)p;
if (cmp > 0) { /* key > p: move right */
demangle.h: Remove uses of PARAMS. include/ 2005-03-26 Gabriel Dos Reis <gdr@integrable-solutions.net> * demangle.h: Remove uses of PARAMS. * libiberty.h (ANSI_PROTOTYPES): Remove guard since ANSI_PROTOTYPES is always assumed. Remove uses of PARAMS throughout. libiberty/ 2005-03-26 Gabriel Dos Reis <gdr@integrable-solutions.net> Convert libiberty to use ISO C prototype style 2/n. * cp-demangle.h: Remove uses of PARAMS. * cp-demangle.c: Likewise. (d_dump, cplus_demangle_fill_name, cplus_demangle_fill_extended_operator, cplus_demangle_fill_ctor, cplus_demangle_fill_dtor, d_make_empty, d_make_comp, d_make_name, d_make_builtin_type, d_make_operator, d_make_extended_operator, d_make_ctor, d_make_dtor, d_make_template_param, d_make_sub, cplus_demangle_mangled_name, has_return_type, is_ctor_dtor_or_conversion, d_encoding, d_name, d_nested_name, d_prefix, d_unqualified_name, d_source_name, d_number, d_identifier, d_operator_name, d_special_name, d_call_offset, d_ctor_dtor_name, cplus_demangle_type, d_cv_qualifiers, d_function_type, d_bare_function_type, d_class_enum_type, d_array_type, d_pointer_to_member_type, d_template_param, d_template_args, d_template_arg, d_expression, d_expr_primary, d_local_name, d_discriminator, d_add_substitution, d_substitution, d_print_resize, d_print_append_char, d_print_append_buffer, d_print_error, cplus_demangle_print, d_print_comp, d_print_java_identifier, d_print_mod_list, d_print_mod, d_print_function_type, d_print_array_type, d_print_expr_op, d_print_cast, cplus_demangle_init_info, d_demangle, __cxa_demangle, cplus_demangle_v3, java_demangle_v3, is_ctor_or_dtor, is_gnu_v3_mangled_ctor, is_gnu_v3_mangled_dtor, print_usage, main): 2005-03-26 Gabriel Dos Reis <gdr@integrable-solutions.net> Convert libiberty to ISO C prototype style 1/n. * _doprnt.c: Remove conditional #include <varargs.h> on ANSI_PROTOTYPES as the latter is always assumed. (_doprnt, checkit, main): Use ISO C prototype. * alloca.c (find_stack_direction, C_alloca): Use ISO C prototype. * argv.c: Remove conditional #includes on ANSI_PROTOTYPES. (dupargv, freeargv, buildargv, main): Use ISO C prototype. * atexit.c (atexit): Likewise * asprintf.c: Remove conditional include on ANSI_PROTOTYPES. (asprintf): Use ISO C prototype. * basename.c (basename): Likewise * bcmp.c (bcmp): Likewise. * bcopy.c (bcopy): Likewise. * bzero.c (bzero): Likewise. * bsearch.c (bsearch): Likewise. Improve const-correctness. * choose-temp.c (choose_temp_base): Likewise. * calloc.c: Remove conditional #include on ANSI_PROTOTYPES. (calloc): Use ISO C prototype. * clock.c (clock): Likewise. * concat.c: Remove conditional #include on ANSI_PROTOTYPES. (vconcat_length, vconcat_copy, concat_length, concat_copy, concat_copy2, concat, reconcat, main): Use ISO C prototype. * copysign.c (copysign): Likewise. From-SVN: r97085
2005-03-26 20:24:33 +01:00
base = (const char *)p + size;
lim--;
} /* else move left */
}
return (NULL);
}