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/* Vector optimized 32/64 bit S/390 version of memchr.
Copyright (C) 2015-2016 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
/* void *memchr (const void *s, int c, size_t n)
Scans memory for character c
and returns pointer to first c.
Register usage:
-r0=tmp
-r1=tmp
-r2=s
-r3=c
-r4=n
-r5=current_len
-v16=part of s
-v17=index of found c
-v18=c replicated
*/
ENTRY(__memchr_vx)
.machine "z13"
.machinemode "zarch_nohighgprs"
# if !defined __s390x__
llgfr %r4,%r4
# endif /* !defined __s390x__ */
clgije %r4,0,.Lnf_end /* If len == 0 then exit. */
vlbb %v16,0(%r2),6 /* Load s until next 4k-byte boundary. */
lcbb %r0,0(%r2),6 /* Get bytes to 4k-byte boundary or 16. */
llgfr %r0,%r0 /* Convert 32bit to 64bit. */
vlvgb %v18,%r3,0 /* Generate vector which elements are all c.
if c > 255, c will be truncated. */
vrepb %v18,%v18,0
lghi %r5,16 /* current_len = 16. */
clgrjhe %r0,%r4,.Llastcmp /* If (bytes to boundary) >= n,
jump to lastcmp. */
vfeebs %v17,%v16,%v18 /* Find c. */
vlgvb %r1,%v17,7 /* Load byte index of c. */
clgrjl %r1,%r0,.Lfound2 /* Found c is within loaded bytes. */
/* Align s to 16 byte. */
risbgn %r1,%r2,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */
slr %r5,%r1 /* Compute bytes to 16bytes boundary. */
lgr %r0,%r5 /* If %r5 + 64 < n? -> loop64. */
aghi %r0,64
clgrjl %r0,%r4,.Lloop64
.Llt64:
vl %v16,0(%r5,%r2)
aghi %r5,16
clgrjhe %r5,%r4,.Llastcmp /* Do last compare if curr-len >= n. */
vfeebs %v17,%v16,%v18 /* Find c. */
jl .Lfound /* Jump away if c was found. */
vl %v16,0(%r5,%r2)
aghi %r5,16
clgrjhe %r5,%r4,.Llastcmp
vfeebs %v17,%v16,%v18
jl .Lfound
vl %v16,0(%r5,%r2)
aghi %r5,16
clgrjhe %r5,%r4,.Llastcmp
vfeebs %v17,%v16,%v18
jl .Lfound
vl %v16,0(%r5,%r2)
aghi %r5,16
.Llastcmp:
/* Use comparision result only if located within first n characters.
%r5: current_len;
%r4: n;
(current_len - n): [0...16[
first ignored match index: vr-width - (current_len - n) ]0...16]
*/
vfeebs %v17,%v16,%v18 /* Find c. */
slgrk %r4,%r5,%r4 /* %r5 = current_len - n. */
lghi %r0,16 /* Register width = 16. */
vlgvb %r1,%v17,7 /* Extract found index or 16 if all equal. */
slr %r0,%r4 /* %r0 = first ignored match index. */
clrjl %r1,%r0,.Lfound2 /* Go away if miscompare is below n bytes. */
/* c not found within n-bytes. */
.Lnf_end:
lghi %r2,0 /* Return null. */
br %r14
.Lfound48:
aghi %r5,16
.Lfound32:
aghi %r5,16
.Lfound16:
aghi %r5,16
.Lfound0:
aghi %r5,16
.Lfound:
vlgvb %r1,%v17,7 /* Load byte index of c. */
.Lfound2:
slgfi %r5,16 /* current_len -=16 */
algr %r5,%r1 /* Zero byte index is added to current len. */
la %r2,0(%r5,%r2) /* Return pointer to c. */
br %r14
.Lloop64:
vl %v16,0(%r5,%r2)
vfeebs %v17,%v16,%v18 /* Find c. */
jl .Lfound0 /* Jump away if c was found. */
vl %v16,16(%r5,%r2)
vfeebs %v17,%v16,%v18
jl .Lfound16
vl %v16,32(%r5,%r2)
vfeebs %v17,%v16,%v18
jl .Lfound32
vl %v16,48(%r5,%r2)
vfeebs %v17,%v16,%v18
jl .Lfound48
aghi %r5,64
lgr %r0,%r5 /* If %r5 + 64 < n? -> loop64. */
aghi %r0,64
clgrjl %r0,%r4,.Lloop64
j .Llt64
END(__memchr_vx)
# define memchr __memchr_c
# undef libc_hidden_builtin_def
# define libc_hidden_builtin_def(name) strong_alias(__memchr_c, __GI_memchr)
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
#include <memchr.S>
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