mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-24 11:41:07 +00:00
208 lines
6.4 KiB
ArmAsm
208 lines
6.4 KiB
ArmAsm
/* Vector optimized 32/64 bit S/390 version of strncpy.
|
|
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
|
|
|
|
/* char * strncpy (const char *dest, const char *src, size_t n)
|
|
Copy at most n characters of string src to dest.
|
|
|
|
Register usage:
|
|
-r0=dest pointer for return
|
|
-r1=tmp, zero byte index
|
|
-r2=dest
|
|
-r3=src
|
|
-r4=n
|
|
-r5=current_len
|
|
-r6=tmp, loaded bytes
|
|
-r7=tmp, border
|
|
-v16=part of src
|
|
-v17=index of zero
|
|
-v18=part of src
|
|
-v31=register save area for r6, r7
|
|
*/
|
|
ENTRY(__strncpy_vx)
|
|
.machine "z13"
|
|
.machinemode "zarch_nohighgprs"
|
|
|
|
# if !defined __s390x__
|
|
llgfr %r4,%r4
|
|
# endif /* !defined __s390x__ */
|
|
|
|
clgfi %r4,0
|
|
ber %r14 /* Nothing to do, if n == 0. */
|
|
lgr %r0,%r2 /* Save destination pointer for return. */
|
|
vlvgp %v31,%r6,%r7 /* Save registers. */
|
|
|
|
vlbb %v16,0(%r3),6 /* Load s until next 4k-byte boundary. */
|
|
lcbb %r6,0(%r3),6 /* Get bytes to 4k-byte boundary or 16. */
|
|
llgfr %r6,%r6 /* Convert 32bit to 64bit. */
|
|
|
|
lghi %r5,0 /* current_len = 0. */
|
|
|
|
clgrjle %r4,%r6,.Lremaining_v16 /* If n <= loaded-bytes
|
|
-> process remaining. */
|
|
|
|
/* n > loaded-byte-count. */
|
|
vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */
|
|
vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */
|
|
clrjl %r1,%r6,.Lfound_v16_store /* Found zero within loaded bytes,
|
|
copy and return. */
|
|
|
|
/* Align s to 16 byte. */
|
|
risbgn %r7,%r3,60,128+63,0 /* %r3 = bits 60-63 of %r2 'and' 15. */
|
|
lghi %r5,15 /* current_len = 15. */
|
|
slr %r5,%r7 /* Compute highest index to 16byte boundary. */
|
|
|
|
/* Zero not found and n > loaded-byte-count. */
|
|
vstl %v16,%r5,0(%r2) /* Copy loaded characters - no zero. */
|
|
ahi %r5,1 /* Start loop at next character. */
|
|
|
|
/* Now we are 16byte aligned, so we can load
|
|
a full vreg without page fault. */
|
|
lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
|
|
aghi %r1,64
|
|
clgrjl %r1,%r4,.Lloop64
|
|
|
|
vl %v16,0(%r5,%r3) /* Load s. */
|
|
clgijl %r4,17,.Lremaining_v16 /* If n <= 16, process remaining
|
|
bytes. */
|
|
.Llt64:
|
|
lgr %r7,%r4
|
|
slgfi %r7,16 /* border_len = n - 16. */
|
|
|
|
clgrjhe %r5,%r7,.Lremaining_v16 /* If current_len >= border
|
|
then process remaining bytes. */
|
|
vfenezbs %v17,%v16,%v16 /* Find element not equal with zero search. */
|
|
je .Lfound_v16 /* Jump away if zero was found. */
|
|
vl %v18,16(%r5,%r3) /* Load next part of s. */
|
|
vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */
|
|
aghi %r5,16
|
|
|
|
clgrjhe %r5,%r7,.Lremaining_v18
|
|
vfenezbs %v17,%v18,%v18
|
|
je .Lfound_v18
|
|
vl %v16,16(%r5,%r3)
|
|
vst %v18,0(%r5,%r2)
|
|
aghi %r5,16
|
|
|
|
clgrjhe %r5,%r7,.Lremaining_v16
|
|
vfenezbs %v17,%v16,%v16
|
|
je .Lfound_v16
|
|
vl %v18,16(%r5,%r3)
|
|
vst %v16,0(%r5,%r2)
|
|
aghi %r5,16
|
|
|
|
.Lremaining_v18:
|
|
vlr %v16,%v18
|
|
.Lremaining_v16:
|
|
/* v16 contains the remaining bytes [1...16].
|
|
Store remaining bytes and append string-termination. */
|
|
vfenezb %v17,%v16,%v16 /* Find element not equal with zero search. */
|
|
slgrk %r7,%r4,%r5 /* Remaining bytes = maxlen - current_len. */
|
|
aghi %r7,-1 /* vstl needs highest index. */
|
|
la %r2,0(%r5,%r2) /* vstl has no index register. */
|
|
vlgvb %r1,%v17,7 /* Load zero index or 16 if not found. */
|
|
/* Zero in remaining bytes? -> jump away (zero-index < max-index)
|
|
Do not jump away if zero-index == max-index,
|
|
but simply copy zero with vstl below. */
|
|
clrjl %r1,%r7,.Lfound_v16_store
|
|
vstl %v16,%r7,0(%r2) /* Store remaining bytes without null
|
|
termination!. */
|
|
.Lend:
|
|
/* Restore saved registers. */
|
|
vlgvg %r6,%v31,0
|
|
vlgvg %r7,%v31,1
|
|
lgr %r2,%r0 /* Load saved dest-ptr. */
|
|
br %r14
|
|
|
|
|
|
.Lfound_v16_32:
|
|
aghi %r5,32
|
|
j .Lfound_v16
|
|
.Lfound_v18_48:
|
|
aghi %r5,32
|
|
.Lfound_v18_16:
|
|
aghi %r5,16
|
|
.Lfound_v18:
|
|
vlr %v16,%v18
|
|
.Lfound_v16:
|
|
/* v16 contains a zero. Store remaining bytes to zero. current_len
|
|
has not reached border, thus checking for n is not needed! */
|
|
vlgvb %r1,%v17,7 /* Load byte index of zero. */
|
|
la %r2,0(%r5,%r2) /* vstl has no support for index-register. */
|
|
.Lfound_v16_store:
|
|
vstl %v16,%r1,0(%r2) /* Copy characters including zero. */
|
|
/* Fill remaining bytes with zero - remaining count always > 0. */
|
|
algr %r5,%r1 /* Remaining bytes (=%r4) = ... */
|
|
slgr %r4,%r5 /* = n - (current_len + zero_index + 1). */
|
|
la %r2,0(%r1,%r2) /* Pointer to zero. start filling beyond. */
|
|
aghi %r4,-2 /* mvc with exrl needs count - 1.
|
|
(additional -1, see remaining bytes above) */
|
|
srlg %r6,%r4,8 /* Split into 256 byte blocks. */
|
|
ltgr %r6,%r6
|
|
je .Lzero_lt256
|
|
.Lzero_loop256:
|
|
mvc 1(256,%r2),0(%r2) /* Fill 256 zeros at once. */
|
|
la %r2,256(%r2)
|
|
brctg %r6,.Lzero_loop256 /* Loop until all blocks are processed. */
|
|
.Lzero_lt256:
|
|
exrl %r4,.Lmvc_lt256
|
|
j .Lend
|
|
.Lmvc_lt256:
|
|
mvc 1(1,%r2),0(%r2)
|
|
|
|
.Lloop64:
|
|
vl %v16,0(%r5,%r3) /* Load s. */
|
|
vfenezbs %v17,%v16,%v16 /* Find element not equal with zero search. */
|
|
je .Lfound_v16 /* Jump away if zero was found. */
|
|
vl %v18,16(%r5,%r3) /* Load next part of s. */
|
|
vst %v16,0(%r5,%r2) /* Store previous part without zero to dst. */
|
|
vfenezbs %v17,%v18,%v18
|
|
je .Lfound_v18_16
|
|
vl %v16,32(%r5,%r3)
|
|
vst %v18,16(%r5,%r2)
|
|
vfenezbs %v17,%v16,%v16
|
|
je .Lfound_v16_32
|
|
vl %v18,48(%r5,%r3)
|
|
vst %v16,32(%r5,%r2)
|
|
vfenezbs %v17,%v18,%v18
|
|
je .Lfound_v18_48
|
|
vst %v18,48(%r5,%r2)
|
|
|
|
aghi %r5,64
|
|
lgr %r1,%r5 /* If %r5 + 64 < maxlen? -> loop64. */
|
|
aghi %r1,64
|
|
clgrjl %r1,%r4,.Lloop64
|
|
|
|
vl %v16,0(%r5,%r3) /* Load s. */
|
|
j .Llt64
|
|
END(__strncpy_vx)
|
|
|
|
# define strncpy __strncpy_c
|
|
# undef libc_hidden_builtin_def
|
|
# define libc_hidden_builtin_def(name) strong_alias(__strncpy_c, __GI_strncpy)
|
|
#endif /* HAVE_S390_VX_ASM_SUPPORT && IS_IN (libc) */
|
|
|
|
/* Include strncpy-implementation in s390-32/s390-64 subdirectory. */
|
|
#include <strncpy.S>
|