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Add and document ffsl(), fls() and flsl().

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This commit is contained in:
Dag-Erling Smørgrav 2004-01-13 16:05:47 +00:00
parent 8746a69a28
commit f434fe1237
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=124483
8 changed files with 204 additions and 12 deletions
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3
include/strings.h
View File

@ -42,6 +42,9 @@ int bcmp(const void *, const void *, size_t); /* LEGACY */
void bcopy(const void *, void *, size_t); /* LEGACY */
void bzero(void *, size_t); /* LEGACY */
int ffs(int);
int ffsl(long);
int fls(int);
int flsl(long);
char *index(const char *, int); /* LEGACY */
char *rindex(const char *, int); /* LEGACY */
int strcasecmp(const char *, const char *);

4
lib/libc/Makefile
View File

@ -83,8 +83,8 @@ SRCS+= ${_src}
KQSRCS= adddi3.c anddi3.c ashldi3.c ashrdi3.c cmpdi2.c divdi3.c iordi3.c \
lshldi3.c lshrdi3.c moddi3.c muldi3.c negdi2.c notdi2.c qdivrem.c \
subdi3.c ucmpdi2.c udivdi3.c umoddi3.c xordi3.c
KSRCS= bcmp.c ffs.c index.c mcount.c rindex.c strcat.c strcmp.c strcpy.c \
strlen.c strncpy.c
KSRCS= bcmp.c ffs.c ffsl.c fls.c flsl.c index.c mcount.c rindex.c \
strcat.c strcmp.c strcpy.c strlen.c strncpy.c
libkern: libkern.gen libkern.${MACHINE_ARCH}

6
lib/libc/string/Makefile.inc
View File

@ -6,7 +6,8 @@
CFLAGS+= -I${.CURDIR}/locale
# machine-independent string sources
MISRCS+=bcmp.c bcopy.c bzero.c ffs.c index.c memccpy.c memchr.c memcmp.c \
MISRCS+=bcmp.c bcopy.c bzero.c ffs.c ffsl.c fls.c flsl.c index.c memccpy.c \
memchr.c memcmp.c \
memcpy.c memmove.c memset.c rindex.c stpcpy.c strcasecmp.c strcat.c \
strchr.c strcmp.c strcoll.c strcpy.c strcspn.c strdup.c strerror.c \
strlcat.c strlcpy.c strlen.c strmode.c strncat.c strncmp.c strncpy.c \
@ -32,6 +33,9 @@ MAN+= bcmp.3 bcopy.3 bstring.3 bzero.3 ffs.3 index.3 memccpy.3 memchr.3 \
strspn.3 strstr.3 strtok.3 strxfrm.3 swab.3 wcscoll.3 wcstok.3 \
wcswidth.3 wcsxfrm.3 wmemchr.3
MLINKS+=ffs.3 ffsl.3
MLINKS+=ffs.3 fls.3
MLINKS+=ffs.3 flsl.3
MLINKS+=index.3 rindex.3
MLINKS+=strcasecmp.3 strncasecmp.3
MLINKS+=strcat.3 strncat.3

41
lib/libc/string/ffs.3
View File

@ -38,23 +38,44 @@
.Dt FFS 3
.Os
.Sh NAME
.Nm ffs
.Nd find first bit set in a bit string
.Nm ffs ,
.Nm ffsl ,
.Nm fls ,
.Nm flsl
.Nd find first or last bit set in a bit string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In strings.h
.Ft int
.Fn ffs "int value"
.Ft int
.Fn ffsl "long value"
.Ft int
.Fn fls "int value"
.Ft int
.Fn flsl "long value"
.Sh DESCRIPTION
The
.Fn ffs
function finds the first bit set in
and
.Fn ffsl
functions find the first bit set in
.Fa value
and returns the index of that bit.
and return the index of that bit.
.Pp
The
.Fn fls
and
.Fn flsl
functions find the last bit set in
.Fa value
and return the index of that bit.
.Pp
Bits are numbered starting from 1, starting at the right-most
bit.
A return value of 0 means that the argument was zero.
(least significant) bit.
A return value of zero from any of these functions means that the
argument was zero.
.Sh SEE ALSO
.Xr bitstring 3
.Sh HISTORY
@ -69,3 +90,11 @@ before it was moved to
for
.St -p1003.1-2001
compliance.
.Pp
The
.Fn ffsl ,
.Fn fls
and
.Fn flsl
functions appeared in
.Fx 5.3 .

6
lib/libc/string/ffs.c
View File

@ -40,7 +40,7 @@ __FBSDID("$FreeBSD$");
#include <strings.h>
/*
* ffs -- vax ffs instruction
* Find First Set bit
*/
int
ffs(int mask)
@ -50,6 +50,6 @@ ffs(int mask)
if (mask == 0)
return(0);
for (bit = 1; !(mask & 1); bit++)
mask >>= 1;
return(bit);
(unsigned int)mask >>= 1;
return (bit);
}

52
lib/libc/string/ffsl.c Normal file
View File

@ -0,0 +1,52 @@
/*-
* Copyright (c) 1990, 1993
* The 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <strings.h>
/*
* Find First Set bit
*/
int
ffsl(long mask)
{
int bit;
if (mask == 0)
return(0);
for (bit = 1; !(mask & 1); bit++)
(unsigned long)mask >>= 1;
return (bit);
}

52
lib/libc/string/fls.c Normal file
View File

@ -0,0 +1,52 @@
/*-
* Copyright (c) 1990, 1993
* The 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <strings.h>
/*
* Find Last Set bit
*/
int
fls(int mask)
{
int bit;
if (mask == 0)
return (0);
for (bit = 1; mask != 1; bit++)
(unsigned int)mask >>= 1;
return (bit);
}

52
lib/libc/string/flsl.c Normal file
View File

@ -0,0 +1,52 @@
/*-
* Copyright (c) 1990, 1993
* The 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <strings.h>
/*
* Find Last Set bit
*/
int
flsl(long mask)
{
int bit;
if (mask == 0)
return (0);
for (bit = 1; mask != 1; bit++)
(unsigned long)mask >>= 1;
return (bit);
}