glibc/sysdeps/s390/s390-32/strncpy-z900.S
Stefan Liebler d1bdbf3809 S390: Refactor strncpy ifunc handling.
The ifunc handling for strncpy is adjusted in order to omit ifunc
variants if those will never be used as the minimum architecture level
already supports newer CPUs by default.
Glibc internal calls will then also use the "newer" ifunc variant.

Note: The fallback s390-32/s390-64 ifunc variants are now moved to
the strncpy-z900.S files. The s390-32/s390-64 files multiarch/strncpy.c
and strncpy.S are deleted.

ChangeLog:

	* sysdeps/s390/multiarch/Makefile
	(sysdep_routines): Remove strncpy variants.
	* sysdeps/s390/Makefile (sysdep_routines): Add strncpy variants.
	* sysdeps/s390/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Refactor ifunc handling for strncpy.
	* sysdeps/s390/multiarch/strncpy-vx.S: Move to ...
	* sysdeps/s390/strncpy-vx.S: ... here and adjust ifunc handling.
	* sysdeps/s390/multiarch/strncpy.c: Move to ...
	* sysdeps/s390/strncpy.c: ... here and adjust ifunc handling.
	* sysdeps/s390/ifunc-strncpy.h: New file.
	* sysdeps/s390/s390-64/strncpy.S: Move to ...
	* sysdeps/s390/s390-64/strncpy-z900.S: ... here
	and adjust ifunc handling.
	* sysdeps/s390/s390-32/strncpy.S: Move to ...
	* sysdeps/s390/s390-32/strncpy-z900.S: ... here
	and adjust ifunc handling.
	* sysdeps/s390/s390-32/multiarch/strncpy.c: Delete file.
	* sysdeps/s390/s390-64/multiarch/strncpy.c: Likewise.
2018-12-18 13:57:11 +01:00

90 lines
2.6 KiB
ArmAsm

/* strncpy - copy at most n characters from a string from source to
destination. For IBM S390
This file is part of the GNU C Library.
Copyright (C) 2000-2018 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
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/>. */
/*
* R2 = address of destination (dst)
* R3 = address of source (src)
* R4 = max of bytes to copy
*/
#include <ifunc-strncpy.h>
#include "sysdep.h"
#include "asm-syntax.h"
#if HAVE_STRNCPY_Z900_G5
ENTRY(STRNCPY_Z900_G5)
.text
st %r2,24(%r15) # save dst pointer
slr %r2,%r3 # %r3 points to src, %r2+%r3 to dst
lhi %r1,3
nr %r1,%r4 # last 2 bits of # bytes
srl %r4,2
ltr %r4,%r4 # less than 4 bytes to copy ?
jz .L1
bras %r5,.L0 # enter loop & load address of a 0
.long 0
.L0: icm %r0,8,0(%r3) # first byte
jz .L3
icm %r0,4,1(%r3) # second byte
jz .L4
icm %r0,2,2(%r3) # third byte
jz .L5
icm %r0,1,3(%r3) # fourth byte
jz .L6
st %r0,0(%r2,%r3) # store all four to dest.
la %r3,4(%r3)
brct %r4,.L0
.L1: ltr %r1,%r1
jz .Lexit
.L2: icm %r0,1,0(%r3)
stc %r0,0(%r2,%r3)
la %r3,1(%r3)
jz .L7
brct %r1,.L2
j .Lexit
.L3: icm %r0,4,0(%r5)
.L4: icm %r0,2,0(%r5)
.L5: icm %r0,1,0(%r5)
.L6: st %r0,0(%r2,%r3)
la %r3,4(%r3)
ahi %r4,-1
j .L8
.L7: ahi %r1,-1
.L8: sll %r4,2
alr %r4,%r1
alr %r2,%r3 # start of dst area to be zeroed
lr %r3,%r4
slr %r4,%r4
slr %r5,%r5
.L9: mvcle %r2,%r4,0 # pad dst with zeroes
jo .L9
.Lexit: l %r2,24(%r15) # return dst pointer
br %r14
END(STRNCPY_Z900_G5)
# if ! HAVE_STRNCPY_IFUNC
strong_alias (STRNCPY_Z900_G5, strncpy)
# endif
# if defined SHARED && IS_IN (libc)
strong_alias (STRNCPY_Z900_G5, __GI_strncpy)
# endif
#endif