glibc/sysdeps/s390/multiarch/memccpy-vx.S

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/* Vector optimized 32/64 bit S/390 version of memccpy.
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 *memccpy (void * dest, const void *src, int c, size_t n)
Copies no more than n bytes from src to dest,
stopping when the character c is found
and returns pointer next to c in dest or null if c not found.
Register usage:
-r0=tmp
-r1=tmp
-r2=dest
-r3=src
-r4=c
-r5=n
-r6=current_len
-v16=part of s
-v17=index of found c
-v18=c replicated
-v19=part #2 of s
-v31=save area for r6
*/
ENTRY(__memccpy_vx)
.machine "z13"
.machinemode "zarch_nohighgprs"
# if !defined __s390x__
llgfr %r5,%r5
# endif /* !defined __s390x__ */
vlvgp %v31,%r6,%r7 /* Save registers. */
clgije %r5,0,.Lnf_end /* If len == 0 then exit. */
vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */
lcbb %r0,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */
llgfr %r0,%r0 /* Convert 32bit to 64bit. */
vlvgb %v18,%r4,0 /* Generate vector which elements are all c.
if c > 255, c will be truncated. */
vrepb %v18,%v18,0
lghi %r6,0 /* current_len = 0. */
clgrjle %r5,%r0,.Lremaining_v16 /* If maxlen <= loaded-bytes
-> Process remaining. */
vfeebs %v17,%v16,%v18 /* Find c. */
vlgvb %r1,%v17,7 /* Load byte index of c. */
clgrjl %r1,%r0,.Lfound_v16 /* Found c is within loaded bytes. */
/* Align s to 16 byte. */
risbgn %r1,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */
lghi %r6,15 /* current_len = 15. */
slr %r6,%r1 /* Compute highest index to 16byte boundary. */
vstl %v16,%r6,0(%r2) /* Store prcessed bytes */
ahi %r6,1
.Lpreloop1:
/* Now we are 16byte aligned, so we can load
a full vreg without page fault. */
vl %v16,0(%r6,%r3) /* Load s. */
clgijl %r5,17,.Lremaining_v16 /* If n <= 16,
process remaining bytes. */
lgr %r7,%r5
slgfi %r7,16 /* border_len = n - 16. */
j .Lloop1
.Lloop2:
vl %v16,16(%r6,%r3)
vst %v19,0(%r6,%r2)
aghi %r6,16
.Lloop1:
clgrjhe %r6,%r7,.Lremaining_v16 /* If current_len >= border
then process remaining bytes. */
vfeebs %v17,%v16,%v18 /* Find c. */
jl .Lfound_v16 /* Jump away if c was found. */
vl %v19,16(%r6,%r3) /* Load next s part. */
vst %v16,0(%r6,%r2) /* Store previous part without c. */
aghi %r6,16
clgrjhe %r6,%r7,.Lremaining_v19
vfeebs %v17,%v19,%v18
jl .Lfound_v19
vl %v16,16(%r6,%r3)
vst %v19,0(%r6,%r2)
aghi %r6,16
clgrjhe %r6,%r7,.Lremaining_v16
vfeebs %v17,%v16,%v18
jl .Lfound_v16
vl %v19,16(%r6,%r3)
vst %v16,0(%r6,%r2)
aghi %r6,16
clgrjhe %r6,%r7,.Lremaining_v19
vfeebs %v17,%v19,%v18
jo .Lloop2
.Lfound_v19:
vlr %v16,%v19
.Lfound_v16:
/* v16 contains c. Store remaining bytes to c. currlen hasn´t
reached border, thus checking for maxlen is not needed! */
vlgvb %r1,%v17,7 /* Load byte index of c. */
la %r2,0(%r6,%r2) /* vstl has no support for index-register. */
.Lfound_v16_store:
vstl %v16,%r1,0(%r2) /* Copy bytes including c. */
la %r2,1(%r1,%r2) /* Return pointer next to c in dest. */
vlgvg %r6,%v31,0
vlgvg %r7,%v31,1
br %r14
.Lremaining_v19:
vlr %v16,%v19
.Lremaining_v16:
/* v16 contains the remaining bytes [1...16].
Check and store remaining bytes. */
vfeebs %v17,%v16,%v18
slgrk %r7,%r5,%r6 /* Remaining bytes = maxlen - current_len. */
aghi %r7,-1 /* vstl needs highest index. */
la %r2,0(%r6,%r2) /* vstl has no index register. */
vlgvb %r1,%v17,7 /* Load index of c or 16 if not found. */
/* c in remaining bytes? -> Jump away (c-index <= max-index) */
clrjle %r1,%r7,.Lfound_v16_store
vstl %v16,%r7,0(%r2) /* Store remaining bytes. */
.Lnf_end:
vlgvg %r6,%v31,0
vlgvg %r7,%v31,1
lghi %r2,0 /* Return null. */
br %r14
END(__memccpy_vx)
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */