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S390: Optimize strncmp and wcsncmp.

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This patch provides optimized versions of strncmp and wcsncmp with the z13
vector instructions.

ChangeLog:

	* sysdeps/s390/multiarch/strncmp-c.c: New File.
	* sysdeps/s390/multiarch/strncmp-vx.S: Likewise.
	* sysdeps/s390/multiarch/strncmp.c: Likewise.
	* sysdeps/s390/multiarch/wcsncmp-c.c: Likewise.
	* sysdeps/s390/multiarch/wcsncmp-vx.S: Likewise.
	* sysdeps/s390/multiarch/wcsncmp.c: Likewise.
	* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add strncmp and
	wcsncmp functions.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add ifunc test for strncmp, wcsncmp.
	* wcsmbs/wcsncmp.c (WCSNCMP): Define and use macro.
	* benchtests/bench-strncmp.c: Add wcsncmp support.
	* benchtests/bench-wcsncmp.c: New File.
	* benchtests/Makefile (wcsmbs-bench): Add wcsncmp.
This commit is contained in:
Stefan Liebler 2015-08-26 10:26:22 +02:00 committed by Andreas Krebbel
parent 63724a6db6
commit cee82e70cc
13 changed files with 558 additions and 29 deletions
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17
ChangeLog
View File

@ -1,3 +1,20 @@
2015-08-26 Stefan Liebler <stli@linux.vnet.ibm.com>
* sysdeps/s390/multiarch/strncmp-c.c: New File.
* sysdeps/s390/multiarch/strncmp-vx.S: Likewise.
* sysdeps/s390/multiarch/strncmp.c: Likewise.
* sysdeps/s390/multiarch/wcsncmp-c.c: Likewise.
* sysdeps/s390/multiarch/wcsncmp-vx.S: Likewise.
* sysdeps/s390/multiarch/wcsncmp.c: Likewise.
* sysdeps/s390/multiarch/Makefile (sysdep_routines): Add strncmp and
wcsncmp functions.
* sysdeps/s390/multiarch/ifunc-impl-list.c
(__libc_ifunc_impl_list): Add ifunc test for strncmp, wcsncmp.
* wcsmbs/wcsncmp.c (WCSNCMP): Define and use macro.
* benchtests/bench-strncmp.c: Add wcsncmp support.
* benchtests/bench-wcsncmp.c: New File.
* benchtests/Makefile (wcsmbs-bench): Add wcsncmp.
2015-08-26 Stefan Liebler <stli@linux.vnet.ibm.com>
* sysdeps/s390/multiarch/strcmp-vx.S: New File.

2
benchtests/Makefile
View File

@ -37,7 +37,7 @@ string-bench := bcopy bzero memccpy memchr memcmp memcpy memmem memmove \
strspn strstr strcpy_chk stpcpy_chk memrchr strsep strtok \
strcoll
wcsmbs-bench := wcslen wcsnlen wcscpy wcpcpy wcsncpy wcpncpy wcscat wcsncat \
wcscmp
wcscmp wcsncmp
string-bench-all := $(string-bench) ${wcsmbs-bench}
# We have to generate locales

110
benchtests/bench-strncmp.c
View File

@ -17,17 +17,68 @@
<http://www.gnu.org/licenses/>. */
#define TEST_MAIN
#define TEST_NAME "strncmp"
#ifdef WIDE
# define TEST_NAME "wcsncmp"
#else
# define TEST_NAME "strncmp"
#endif /* !WIDE */
#include "bench-string.h"
typedef int (*proto_t) (const char *, const char *, size_t);
int simple_strncmp (const char *, const char *, size_t);
int stupid_strncmp (const char *, const char *, size_t);
#ifdef WIDE
# include <wchar.h>
IMPL (stupid_strncmp, 0)
IMPL (simple_strncmp, 0)
IMPL (strncmp, 1)
# define L(str) L##str
# define STRNCMP wcsncmp
# define SIMPLE_STRNCMP simple_wcsncmp
# define STUPID_STRNCMP stupid_wcsncmp
# define CHAR wchar_t
# define CHARBYTES 4
/* Wcsncmp uses signed semantics for comparison, not unsigned.
Avoid using substraction since possible overflow. */
int
simple_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
{
wchar_t c1, c2;
while (n--)
{
c1 = *s1++;
c2 = *s2++;
if (c1 == L ('\0') || c1 != c2)
return c1 > c2 ? 1 : (c1 < c2 ? -1 : 0);
}
return 0;
}
int
stupid_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
{
wchar_t c1, c2;
size_t ns1 = wcsnlen (s1, n) + 1, ns2 = wcsnlen (s2, n) + 1;
n = ns1 < n ? ns1 : n;
n = ns2 < n ? ns2 : n;
while (n--)
{
c1 = *s1++;
c2 = *s2++;
if (c1 != c2)
return c1 > c2 ? 1 : -1;
}
return 0;
}
#else
# define L(str) str
# define STRNCMP strncmp
# define SIMPLE_STRNCMP simple_strncmp
# define STUPID_STRNCMP stupid_strncmp
# define CHAR char
# define CHARBYTES 1
/* Strncmp uses unsigned semantics for comparison. */
int
simple_strncmp (const char *s1, const char *s2, size_t n)
{
@ -46,12 +97,21 @@ stupid_strncmp (const char *s1, const char *s2, size_t n)
n = ns1 < n ? ns1 : n;
n = ns2 < n ? ns2 : n;
while (n-- && (ret = *(unsigned char *) s1++ - * (unsigned char *) s2++) == 0);
while (n-- && (ret = *(unsigned char *) s1++ - *(unsigned char *) s2++) == 0);
return ret;
}
#endif /* !WIDE */
typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
IMPL (STUPID_STRNCMP, 0)
IMPL (SIMPLE_STRNCMP, 0)
IMPL (STRNCMP, 1)
static void
do_one_test (impl_t *impl, const char *s1, const char *s2, size_t n,
do_one_test (impl_t *impl, const CHAR *s1, const CHAR *s2, size_t n,
int exp_result)
{
size_t i, iters = INNER_LOOP_ITERS;
@ -74,12 +134,12 @@ do_test_limit (size_t align1, size_t align2, size_t len, size_t n, int max_char,
int exp_result)
{
size_t i, align_n;
char *s1, *s2;
CHAR *s1, *s2;
if (n == 0)
{
s1 = (char*)(buf1 + page_size);
s2 = (char*)(buf2 + page_size);
s1 = (CHAR *) (buf1 + page_size);
s2 = (CHAR *) (buf2 + page_size);
printf ("Length %4zd/%4zd:", len, n);
FOR_EACH_IMPL (impl, 0)
@ -92,16 +152,16 @@ do_test_limit (size_t align1, size_t align2, size_t len, size_t n, int max_char,
align1 &= 15;
align2 &= 15;
align_n = (page_size - n) & 15;
align_n = (page_size - n * CHARBYTES) & 15;
s1 = (char*)(buf1 + page_size - n);
s2 = (char*)(buf2 + page_size - n);
s1 = (CHAR *) (buf1 + page_size - n * CHARBYTES);
s2 = (CHAR *) (buf2 + page_size - n * CHARBYTES);
if (align1 < align_n)
s1 -= (align_n - align1);
s1 = (CHAR *) ((char *) s1 - (align_n - align1));
if (align2 < align_n)
s2 -= (align_n - align2);
s2 = (CHAR *) ((char *) s2 - (align_n - align2));
for (i = 0; i < n; i++)
s1[i] = s2[i] = 1 + 23 * i % max_char;
@ -129,24 +189,24 @@ do_test (size_t align1, size_t align2, size_t len, size_t n, int max_char,
int exp_result)
{
size_t i;
char *s1, *s2;
CHAR *s1, *s2;
if (n == 0)
return;
align1 &= 7;
if (align1 + n + 1 >= page_size)
align1 &= 63;
if (align1 + (n + 1) * CHARBYTES >= page_size)
return;
align2 &= 7;
if (align2 + n + 1 >= page_size)
if (align2 + (n + 1) * CHARBYTES >= page_size)
return;
s1 = (char*)(buf1 + align1);
s2 = (char*)(buf2 + align2);
s1 = (CHAR *) (buf1 + align1);
s2 = (CHAR *) (buf2 + align2);
for (i = 0; i < n; i++)
s1[i] = s2[i] = 1 + 23 * i % max_char;
s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;
s1[n] = 24 + exp_result;
s2[n] = 23;
@ -162,7 +222,7 @@ do_test (size_t align1, size_t align2, size_t len, size_t n, int max_char,
printf ("Length %4zd/%4zd, alignment %2zd/%2zd:", len, n, align1, align2);
FOR_EACH_IMPL (impl, 0)
do_one_test (impl, (char*)s1, (char*)s2, n, exp_result);
do_one_test (impl, s1, s2, n, exp_result);
putchar ('\n');
}

20
benchtests/bench-wcsncmp.c Normal file
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@ -0,0 +1,20 @@
/* Measure wcsncmp functions.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#define WIDE 1
#include "bench-strncmp.c"

6
sysdeps/s390/multiarch/Makefile
View File

@ -7,7 +7,8 @@ sysdep_routines += strlen strlen-vx strlen-c \
stpncpy stpncpy-vx stpncpy-c \
strcat strcat-vx strcat-c \
strncat strncat-vx strncat-c \
strcmp strcmp-vx
strcmp strcmp-vx \
strncmp strncmp-vx strncmp-c
endif
ifeq ($(subdir),wcsmbs)
@ -19,5 +20,6 @@ sysdep_routines += wcslen wcslen-vx wcslen-c \
wcpncpy wcpncpy-vx wcpncpy-c \
wcscat wcscat-vx wcscat-c \
wcsncat wcsncat-vx wcsncat-c \
wcscmp wcscmp-vx wcscmp-c
wcscmp wcscmp-vx wcscmp-c \
wcsncmp wcsncmp-vx wcsncmp-c
endif

3
sysdeps/s390/multiarch/ifunc-impl-list.c
View File

@ -106,6 +106,9 @@ __libc_ifunc_impl_list (const char *name, struct libc_ifunc_impl *array,
IFUNC_VX_IMPL (strcmp);
IFUNC_VX_IMPL (wcscmp);
IFUNC_VX_IMPL (strncmp);
IFUNC_VX_IMPL (wcsncmp);
#endif /* HAVE_S390_VX_ASM_SUPPORT */
return i;

28
sysdeps/s390/multiarch/strncmp-c.c Normal file
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@ -0,0 +1,28 @@
/* Default strncmp implementation for S/390.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
# define STRNCMP __strncmp_c
# ifdef SHARED
# undef libc_hidden_builtin_def
# define libc_hidden_builtin_def(name) \
__hidden_ver1 (__strncmp_c, __GI_strncmp, __strncmp_c);
# endif /* SHARED */
# include <string/strncmp.c>
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */

137
sysdeps/s390/multiarch/strncmp-vx.S Normal file
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@ -0,0 +1,137 @@
/* Vector optimized 32/64 bit S/390 version of strncmp.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
# include "sysdep.h"
# include "asm-syntax.h"
.text
/* int strncmp (const char *s1, const char *s2, size_t n)
Compare at most n characters of two strings.
Register usage:
-r0=tmp
-r1=tmp
-r2=s1
-r3=s2
-r4=n
-r5=current_len
-v16=part of s1
-v17=part of s2
-v18=index of unequal
*/
ENTRY(__strncmp_vx)
.machine "z13"
.machinemode "zarch_nohighgprs"
# if !defined __s390x__
llgfr %r4,%r4
# endif /* !defined __s390x__ */
clgije %r4,0,.Lend_equal /* Nothing to do if n == 0, */
lghi %r5,0 /* current_len = 0. */
.Lloop:
vlbb %v16,0(%r5,%r2),6 /* Load s1 to block boundary. */
vlbb %v17,0(%r5,%r3),6 /* Load s2 to block boundary. */
lcbb %r0,0(%r5,%r2),6 /* Get loaded byte count of s1. */
jo .Llt16_1 /* Jump away if vr is not fully loaded. */
lcbb %r1,0(%r5,%r3),6 /* Get loaded byte count of s2. */
jo .Llt16_2 /* Jump away if vr is not fully loaded. */
aghi %r5,16 /* Both vrs are fully loaded. */
clgrjhe %r5,%r4,.Llastcmp /* If current_len >= n ->last compare. */
vfenezbs %v18,%v16,%v17 /* Compare not equal with zero search. */
jno .Lfound
vlbb %v16,0(%r5,%r2),6
vlbb %v17,0(%r5,%r3),6
lcbb %r0,0(%r5,%r2),6
jo .Llt16_1
lcbb %r1,0(%r5,%r3),6
jo .Llt16_2
aghi %r5,16
clgrjhe %r5,%r4,.Llastcmp
vfenezbs %v18,%v16,%v17
jno .Lfound
vlbb %v16,0(%r5,%r2),6
vlbb %v17,0(%r5,%r3),6
lcbb %r0,0(%r5,%r2),6
jo .Llt16_1
lcbb %r1,0(%r5,%r3),6
jo .Llt16_2
aghi %r5,16
clgrjhe %r5,%r4,.Llastcmp
vfenezbs %v18,%v16,%v17
jno .Lfound
vlbb %v16,0(%r5,%r2),6
vlbb %v17,0(%r5,%r3),6
lcbb %r0,0(%r5,%r2),6
jo .Llt16_1
lcbb %r1,0(%r5,%r3),6
jo .Llt16_2
aghi %r5,16
clgrjhe %r5,%r4,.Llastcmp
vfenezbs %v18,%v16,%v17
jno .Lfound
j .Lloop
.Llt16_1:
lcbb %r1,0(%r5,%r3),6 /* Get loaded byte count ofs2. */
.Llt16_2:
clr %r0,%r1 /* Compare logical. */
locrh %r0,%r1 /* Compute minimum of bytes loaded. */
algfr %r5,%r0 /* Add smallest loaded bytes to current_len. */
clgrj %r5,%r4,10,.Llastcmp /* If current_len >= n ->last compare. */
vfenezbs %v18,%v16,%v17 /* Compare not equal with zero search. */
vlgvb %r1,%v18,7 /* Get not equal index or 16 if all equal. */
clrjl %r1,%r0,.Lfound /* Jump away if miscompare is within
loaded bytes (index < loaded-bytes) */
j .Lloop
.Llastcmp:
/* Use comparision result only if located within first n characters.
%r0: loaded byte count in vreg;
%r5: current_len;
%r4: n;
(current_len - n): [0...16[
First ignored match index: loaded bytes - (current_len-n): ]0...16]
*/
slgr %r5,%r4 /* %r5 = current_len - n. */
slr %r0,%r5 /* %r0 = first ignored match index. */
vfenezbs %v18,%v16,%v17 /* Compare not equal with zero search. */
vlgvb %r1,%v18,7 /* Get not equal index or 16 if all equal. */
clrjl %r1,%r0,.Lfound /* Jump away if miscompare is within
loaded bytes and below n bytes. */
j .Lend_equal /* Miscompare after n-bytes -> end equal. */
.Lfound:
/* Difference or end of string. */
je .Lend_equal
lghi %r2,1
lghi %r1,-1
locgrl %r2,%r1
br %r14
.Lend_equal:
lghi %r2,0
br %r14
END(__strncmp_vx)
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */

30
sysdeps/s390/multiarch/strncmp.c Normal file
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@ -0,0 +1,30 @@
/* Multiple versions of strncmp.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
# include <string.h>
# include <ifunc-resolve.h>
# undef strcmp
extern __typeof (strncmp) __strncmp;
s390_vx_libc_ifunc2 (__strncmp, strncmp)
#else
# include <string/strncmp.c>
#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */

25
sysdeps/s390/multiarch/wcsncmp-c.c Normal file
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@ -0,0 +1,25 @@
/* Default wcsncmp implementation for S/390.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
# define WCSNCMP __wcsncmp_c
# include <wchar.h>
extern __typeof (wcsncmp) __wcsncmp_c;
# include <wcsmbs/wcsncmp.c>
#endif

177
sysdeps/s390/multiarch/wcsncmp-vx.S Normal file
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@ -0,0 +1,177 @@
/* Vector optimized 32/64 bit S/390 version of wcsncmp.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
# include "sysdep.h"
# include "asm-syntax.h"
.text
/* int wcsncmp (const wchar_t *s1, const wchar_t *s2, size_t n)
Compare at most n characters of two strings.
Register usage:
-r0=tmp
-r1=tmp
-r2=s1
-r3=s2
-r4=n
-r5=current_len
-v16=part of s1
-v17=part of s2
-v18=index of unequal
*/
ENTRY(__wcsncmp_vx)
.machine "z13"
.machinemode "zarch_nohighgprs"
# if !defined __s390x__
llgfr %r4,%r4
# endif /* !defined __s390x__ */
clgije %r4,0,.Lend_equal /* Nothing to do if n == 0. */
/* Check range of n and convert to byte-count. */
# ifdef __s390x__
tmhh %r4,49152 /* Test bit 0 or 1 of maxlen. */
lghi %r1,-4 /* Max byte-count is 18446744073709551612. */
# else
tmlh %r4,49152 /* Test bit 0 or 1 of maxlen. */
llilf %r1,4294967292 /* Max byte-count is 4294967292. */
# endif /* !__s390x__ */
sllg %r4,%r4,2 /* Convert character-count to byte-count. */
locgrne %r4,%r1 /* Use max byte-count, if bit 0/1 was one. */
/* Check first character without vector load. */
lghi %r5,4 /* current_len = 4 bytes. */
/* Check s1/2[0]. */
lt %r0,0(%r2)
l %r1,0(%r3)
je .Lend_cmp_one_char
crjne %r0,%r1,.Lend_cmp_one_char
.Lloop:
vlbb %v17,0(%r5,%r3),6 /* Load s2 to block boundary. */
vlbb %v16,0(%r5,%r2),6 /* Load s1 to block boundary. */
lcbb %r0,0(%r5,%r2),6 /* Get loaded byte count of s1. */
jo .Llt16_1 /* Jump away if vector not fully loaded. */
lcbb %r1,0(%r5,%r3),6 /* Get loaded byte count of s2. */
jo .Llt16_2 /* Jump away if vector not fully loaded. */
aghi %r5,16 /* Both vectors are fully loaded. */
vfenezfs %v18,%v16,%v17 /* Compare not equal with zero search. */
clgrjhe %r5,%r4,.Llastcmp /* If current_len >= n ->last compare. */
jno .Lfound
vlbb %v17,0(%r5,%r3),6
vlbb %v16,0(%r5,%r2),6
lcbb %r0,0(%r5,%r2),6
jo .Llt16_1
lcbb %r1,0(%r5,%r3),6
jo .Llt16_2
aghi %r5,16
vfenezfs %v18,%v16,%v17
clgrjhe %r5,%r4,.Llastcmp
jno .Lfound
vlbb %v17,0(%r5,%r3),6
vlbb %v16,0(%r5,%r2),6
lcbb %r0,0(%r5,%r2),6
jo .Llt16_1
lcbb %r1,0(%r5,%r3),6
jo .Llt16_2
aghi %r5,16
vfenezfs %v18,%v16,%v17
clgrjhe %r5,%r4,.Llastcmp
jno .Lfound
vlbb %v17,0(%r5,%r3),6
vlbb %v16,0(%r5,%r2),6
lcbb %r0,0(%r5,%r2),6
jo .Llt16_1
lcbb %r1,0(%r5,%r3),6
jo .Llt16_2
aghi %r5,16
vfenezfs %v18,%v16,%v17
clgrjhe %r5,%r4,.Llastcmp
jno .Lfound
j .Lloop
.Llt16_1:
lcbb %r1,0(%r5,%r3),6 /* Get loaded byte count of s2. */
.Llt16_2:
clr %r0,%r1 /* Compare logical. */
locrh %r0,%r1 /* Compute minimum of bytes loaded. */
nill %r0,65532 /* Align bytes loaded to full characters. */
jz .Lcmp_one_char /* Jump away if no full char is available. */
.Llt_cmp:
algfr %r5,%r0 /* Add smallest loaded bytes to current_len. */
vfenezfs %v18,%v16,%v17 /* Compare not equal with zero search. */
clgrj %r5,%r4,10,.Llastcmp /* If current_len >= n -> last compare */
vlgvb %r1,%v18,7 /* Get not equal index or 16 if all equal. */
clrjl %r1,%r0,.Lfound /* Jump away if miscompare is within
loaded bytes; (index < loaded-bytes) */
j .Lloop
.Lcmp_one_char:
/* At least one of both strings is not 4-byte aligned
and there is no full character before next block-boundary.
Compare one character to get over the boundary and
proceed with normal loop! */
vlef %v16,0(%r5,%r2),0 /* Load one character. */
lghi %r0,4 /* Loaded byte count is 4. */
vlef %v17,0(%r5,%r3),0
j .Llt_cmp /* Proceed with comparision. */
.Llastcmp:
/* Use comparision result only if located within first n characters.
%r0: loaded byte count in vreg;
%r5: current_len;
%r4: n;
(current_len - n): [0...16[
First ignored match index: loaded bytes - (current_len-n): ]0...16]
*/
slgr %r5,%r4 /* %r5 = current_len - n. */
slr %r0,%r5 /* %r0 = first ignored match index. */
vlgvb %r4,%v18,7 /* Get not equal index or 16 if all equal. */
clrjl %r4,%r0,.Lfound2 /* Jump away if miscompare is within
loaded bytes and below n bytes. */
.Lend_equal:
lghi %r2,0
br %r14
.Lfound:
/* Difference or end of string. */
/* vfenezf found an unequal element or zero.
This instruction compares unsigned words, but wchar_t is signed.
Thus we have to compare the found element again. */
vlgvb %r4,%v18,7 /* Extract not equal byte-index. */
.Lfound2:
srl %r4,2 /* And convert it to character-index. */
vlgvf %r0,%v16,0(%r4) /* Load character-values. */
vlgvf %r1,%v17,0(%r4)
.Lend_cmp_one_char:
cr %r0,%r1
je .Lend_equal
lghi %r2,1
lghi %r1,-1
locgrl %r2,%r1
br %r14
END(__wcsncmp_vx)
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */

27
sysdeps/s390/multiarch/wcsncmp.c Normal file
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@ -0,0 +1,27 @@
/* Multiple versions of wcsncmp.
Copyright (C) 2015 Free Software Foundation, Inc.
This file is part of the GNU C Library.
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/>. */
#if defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)
# include <wchar.h>
# include <ifunc-resolve.h>
s390_vx_libc_ifunc2 (__wcsncmp, wcsncmp)
#else
# include <wcsmbs/wcsncmp.c>
#endif /* !(defined HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc)) */

5
wcsmbs/wcsncmp.c
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@ -18,13 +18,16 @@
#include <wchar.h>
#ifndef WCSNCMP
# define WCSNCMP wcsncmp
#endif
/* Compare no more than N characters of S1 and S2,
returning less than, equal to or greater than zero
if S1 is lexicographically less than, equal to or
greater than S2. */
int
wcsncmp (s1, s2, n)
WCSNCMP (s1, s2, n)
const wchar_t *s1;
const wchar_t *s2;
size_t n;