Improve generic strcspn performance
Improve strcspn performance using a much faster algorithm. It is kept simple so it works well on most targets. It is generally at least 10 times faster than the existing implementation on bench-strcspn on a few AArch64 implementations, and for some tests 100 times as fast (repeatedly calling strchr on a small string is extremely slow...). In fact the string/bits/string2.h inlines make no longer sense, as GCC already uses strlen if reject is an empty string, strchrnul is 5 times as fast as __strcspn_c1, while __strcspn_c2 and __strcspn_c3 are slower than the strcspn main loop for large strings (though reject length 2-4 could be special cased in the future to gain even more performance). Tested on x86_64, i686, and aarch64. * string/Version (libc): Add GLIBC_2.24. * string/strcspn.c (strcspn): Rewrite function. * string/bits/string2.h (strcspn): Use __builtin_strcspn. (__strcspn_c1): Remove inline function. (__strcspn_c2): Likewise. (__strcspn_c3): Likewise. * string/string-inline.c [SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c1): Add compatibility symbol. [SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c2): Likewise. [SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c3): Likewise. * sysdeps/i386/string-inlines.c: Include generic string-inlines.c.
This commit is contained in:
Wilco Dijkstra
Adhemerval Zanella
parent
d8a012c5c9
commit
d3496c9f4f
18
ChangeLog
18
ChangeLog
@ -1,3 +1,21 @@
|
||||
2016-04-01 Wilco Dijkstra <wdijkstr@arm.com>
|
||||
Adhemerval Zanella <adhemerval.zanella@linaro.org>
|
||||
|
||||
* string/Version (libc): Add GLIBC_2.24.
|
||||
* string/strcspn.c (strcspn): Rewrite function.
|
||||
* string/bits/string2.h (strcspn): Use __builtin_strcspn.
|
||||
(__strcspn_c1): Remove inline function.
|
||||
(__strcspn_c2): Likewise.
|
||||
(__strcspn_c3): Likewise.
|
||||
* string/string-inline.c
|
||||
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c1): Add
|
||||
compatibility symbol.
|
||||
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c2):
|
||||
Likewise.
|
||||
[SHLIB_COMPAT(libc, GLIBC_2_1_1, GLIBC_2_24)] (__strcspn_c3):
|
||||
Likewise.
|
||||
* sysdeps/i386/string-inlines.c: Include generic string-inlines.c.
|
||||
|
||||
2016-04-01 Stefan Liebler <stli@linux.vnet.ibm.com>
|
||||
|
||||
* sysdeps/s390/s390-32/dl-trampoline.h (_dl_runtime_resolve):
|
||||
|
||||
@ -80,4 +80,6 @@ libc {
|
||||
GLIBC_2.6 {
|
||||
strerror_l;
|
||||
}
|
||||
GLIBC_2.24 {
|
||||
}
|
||||
}
|
||||
|
||||
@ -905,77 +905,10 @@ __stpcpy_small (char *__dest,
|
||||
|
||||
/* Return the length of the initial segment of S which
|
||||
consists entirely of characters not in REJECT. */
|
||||
#if !defined _HAVE_STRING_ARCH_strcspn || defined _FORCE_INLINES
|
||||
# ifndef _HAVE_STRING_ARCH_strcspn
|
||||
# if __GNUC_PREREQ (3, 2)
|
||||
# define strcspn(s, reject) \
|
||||
__extension__ \
|
||||
({ char __r0, __r1, __r2; \
|
||||
(__builtin_constant_p (reject) && __string2_1bptr_p (reject) \
|
||||
? ((__builtin_constant_p (s) && __string2_1bptr_p (s)) \
|
||||
? __builtin_strcspn (s, reject) \
|
||||
: ((__r0 = ((const char *) (reject))[0], __r0 == '\0') \
|
||||
? strlen (s) \
|
||||
: ((__r1 = ((const char *) (reject))[1], __r1 == '\0') \
|
||||
? __strcspn_c1 (s, __r0) \
|
||||
: ((__r2 = ((const char *) (reject))[2], __r2 == '\0') \
|
||||
? __strcspn_c2 (s, __r0, __r1) \
|
||||
: (((const char *) (reject))[3] == '\0' \
|
||||
? __strcspn_c3 (s, __r0, __r1, __r2) \
|
||||
: __builtin_strcspn (s, reject)))))) \
|
||||
: __builtin_strcspn (s, reject)); })
|
||||
# else
|
||||
# define strcspn(s, reject) \
|
||||
__extension__ \
|
||||
({ char __r0, __r1, __r2; \
|
||||
(__builtin_constant_p (reject) && __string2_1bptr_p (reject) \
|
||||
? ((__r0 = ((const char *) (reject))[0], __r0 == '\0') \
|
||||
? strlen (s) \
|
||||
: ((__r1 = ((const char *) (reject))[1], __r1 == '\0') \
|
||||
? __strcspn_c1 (s, __r0) \
|
||||
: ((__r2 = ((const char *) (reject))[2], __r2 == '\0') \
|
||||
? __strcspn_c2 (s, __r0, __r1) \
|
||||
: (((const char *) (reject))[3] == '\0' \
|
||||
? __strcspn_c3 (s, __r0, __r1, __r2) \
|
||||
: strcspn (s, reject))))) \
|
||||
: strcspn (s, reject)); })
|
||||
# endif
|
||||
#ifndef _HAVE_STRING_ARCH_strcspn
|
||||
# if __GNUC_PREREQ (3, 2)
|
||||
# define strcspn(s, reject) __builtin_strcspn (s, reject)
|
||||
# endif
|
||||
|
||||
__STRING_INLINE size_t __strcspn_c1 (const char *__s, int __reject);
|
||||
__STRING_INLINE size_t
|
||||
__strcspn_c1 (const char *__s, int __reject)
|
||||
{
|
||||
size_t __result = 0;
|
||||
while (__s[__result] != '\0' && __s[__result] != __reject)
|
||||
++__result;
|
||||
return __result;
|
||||
}
|
||||
|
||||
__STRING_INLINE size_t __strcspn_c2 (const char *__s, int __reject1,
|
||||
int __reject2);
|
||||
__STRING_INLINE size_t
|
||||
__strcspn_c2 (const char *__s, int __reject1, int __reject2)
|
||||
{
|
||||
size_t __result = 0;
|
||||
while (__s[__result] != '\0' && __s[__result] != __reject1
|
||||
&& __s[__result] != __reject2)
|
||||
++__result;
|
||||
return __result;
|
||||
}
|
||||
|
||||
__STRING_INLINE size_t __strcspn_c3 (const char *__s, int __reject1,
|
||||
int __reject2, int __reject3);
|
||||
__STRING_INLINE size_t
|
||||
__strcspn_c3 (const char *__s, int __reject1, int __reject2,
|
||||
int __reject3)
|
||||
{
|
||||
size_t __result = 0;
|
||||
while (__s[__result] != '\0' && __s[__result] != __reject1
|
||||
&& __s[__result] != __reject2 && __s[__result] != __reject3)
|
||||
++__result;
|
||||
return __result;
|
||||
}
|
||||
#endif
|
||||
|
||||
|
||||
|
||||
@ -16,6 +16,7 @@
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
#include <string.h>
|
||||
#include <stdint.h>
|
||||
|
||||
#undef strcspn
|
||||
|
||||
@ -26,16 +27,45 @@
|
||||
/* Return the length of the maximum initial segment of S
|
||||
which contains no characters from REJECT. */
|
||||
size_t
|
||||
STRCSPN (const char *s, const char *reject)
|
||||
STRCSPN (const char *str, const char *reject)
|
||||
{
|
||||
size_t count = 0;
|
||||
if (__glibc_unlikely (reject[0] == '\0') ||
|
||||
__glibc_unlikely (reject[1] == '\0'))
|
||||
return __strchrnul (str, reject [0]) - str;
|
||||
|
||||
while (*s != '\0')
|
||||
if (strchr (reject, *s++) == NULL)
|
||||
++count;
|
||||
else
|
||||
return count;
|
||||
/* Use multiple small memsets to enable inlining on most targets. */
|
||||
unsigned char table[256];
|
||||
unsigned char *p = memset (table, 0, 64);
|
||||
memset (p + 64, 0, 64);
|
||||
memset (p + 128, 0, 64);
|
||||
memset (p + 192, 0, 64);
|
||||
|
||||
return count;
|
||||
unsigned char *s = (unsigned char*) reject;
|
||||
unsigned char tmp;
|
||||
do
|
||||
p[tmp = *s++] = 1;
|
||||
while (tmp);
|
||||
|
||||
s = (unsigned char*) str;
|
||||
if (p[s[0]]) return 0;
|
||||
if (p[s[1]]) return 1;
|
||||
if (p[s[2]]) return 2;
|
||||
if (p[s[3]]) return 3;
|
||||
|
||||
s = (unsigned char *) ((uintptr_t)(s) & ~3);
|
||||
|
||||
unsigned int c0, c1, c2, c3;
|
||||
do
|
||||
{
|
||||
s += 4;
|
||||
c0 = p[s[0]];
|
||||
c1 = p[s[1]];
|
||||
c2 = p[s[2]];
|
||||
c3 = p[s[3]];
|
||||
}
|
||||
while ((c0 | c1 | c2 | c3) == 0);
|
||||
|
||||
size_t count = s - (unsigned char *) str;
|
||||
return (c0 | c1) != 0 ? count - c0 + 1 : count - c2 + 3;
|
||||
}
|
||||
libc_hidden_builtin_def (strcspn)
|
||||
|
||||
@ -32,3 +32,43 @@
|
||||
#undef __NO_INLINE__
|
||||
#include <bits/string.h>
|
||||
#include <bits/string2.h>
|
||||
|
||||
#include "shlib-compat.h"
|
||||
|
||||
#if SHLIB_COMPAT (libc, GLIBC_2_1_1, GLIBC_2_24)
|
||||
/* The inline functions are not used from GLIBC 2.24 and forward, however
|
||||
they are required to provide the symbols through string-inlines.c
|
||||
(if inlining is not possible for compatibility reasons). */
|
||||
size_t
|
||||
__old_strcspn_c1 (const char *__s, int __reject)
|
||||
{
|
||||
size_t __result = 0;
|
||||
while (__s[__result] != '\0' && __s[__result] != __reject)
|
||||
++__result;
|
||||
return __result;
|
||||
}
|
||||
compat_symbol (libc, __old_strcspn_c1, __strcspn_c1, GLIBC_2_1_1);
|
||||
|
||||
size_t
|
||||
__old_strcspn_c2 (const char *__s, int __reject1, int __reject2)
|
||||
{
|
||||
size_t __result = 0;
|
||||
while (__s[__result] != '\0' && __s[__result] != __reject1
|
||||
&& __s[__result] != __reject2)
|
||||
++__result;
|
||||
return __result;
|
||||
}
|
||||
compat_symbol (libc, __old_strcspn_c2, __strcspn_c2, GLIBC_2_1_1);
|
||||
|
||||
size_t
|
||||
__old_strcspn_c3 (const char *__s, int __reject1, int __reject2,
|
||||
int __reject3)
|
||||
{
|
||||
size_t __result = 0;
|
||||
while (__s[__result] != '\0' && __s[__result] != __reject1
|
||||
&& __s[__result] != __reject2 && __s[__result] != __reject3)
|
||||
++__result;
|
||||
return __result;
|
||||
}
|
||||
compat_symbol (libc, __old_strcspn_c3, __strcspn_c3, GLIBC_2_1_1);
|
||||
#endif
|
||||
|
||||
@ -15,27 +15,10 @@
|
||||
License along with the GNU C Library; if not, see
|
||||
<http://www.gnu.org/licenses/>. */
|
||||
|
||||
/* <bits/string.h> and <bits/string2.h> declare some extern inline
|
||||
functions. These functions are declared additionally here if
|
||||
inlining is not possible. */
|
||||
|
||||
#undef __USE_STRING_INLINES
|
||||
#define __USE_STRING_INLINES
|
||||
#define _FORCE_INLINES
|
||||
#define __STRING_INLINE /* empty */
|
||||
#define __NO_INLINE__
|
||||
|
||||
/* This is to avoid PLT entries for the x86 version. */
|
||||
#define __memcpy_g __memcpy_g_internal
|
||||
#define __strchr_g __strchr_g_internal
|
||||
|
||||
#include <string.h>
|
||||
#undef index
|
||||
#undef rindex
|
||||
|
||||
#undef __NO_INLINE__
|
||||
#include <bits/string.h>
|
||||
#include <bits/string2.h>
|
||||
#include <string/string-inlines.c>
|
||||
|
||||
void *
|
||||
(__memcpy_c) (void *d, const void *s, size_t n)
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user