mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-12 06:10:10 +00:00
2b778ceb40
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
188 lines
4.4 KiB
ArmAsm
188 lines
4.4 KiB
ArmAsm
/* strcpy/stpcpy - copy a string returning pointer to start/end.
|
|
Copyright (C) 2013-2021 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
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
/* To build as stpcpy, define BUILD_STPCPY before compiling this file.
|
|
|
|
To test the page crossing code path more thoroughly, compile with
|
|
-DSTRCPY_TEST_PAGE_CROSS - this will force all unaligned copies through
|
|
the slower entry path. This option is not intended for production use. */
|
|
|
|
#include <sysdep.h>
|
|
|
|
/* Assumptions:
|
|
*
|
|
* ARMv8-a, AArch64, Advanced SIMD.
|
|
* MTE compatible.
|
|
*/
|
|
|
|
/* Arguments and results. */
|
|
#define dstin x0
|
|
#define srcin x1
|
|
#define result x0
|
|
|
|
#define src x2
|
|
#define dst x3
|
|
#define len x4
|
|
#define synd x4
|
|
#define tmp x5
|
|
#define wtmp w5
|
|
#define shift x5
|
|
#define data1 x6
|
|
#define dataw1 w6
|
|
#define data2 x7
|
|
#define dataw2 w7
|
|
|
|
#define dataq q0
|
|
#define vdata v0
|
|
#define vhas_nul v1
|
|
#define vrepmask v2
|
|
#define vend v3
|
|
#define dend d3
|
|
#define dataq2 q1
|
|
|
|
#ifdef BUILD_STPCPY
|
|
# define STRCPY __stpcpy
|
|
# define IFSTPCPY(X,...) X,__VA_ARGS__
|
|
#else
|
|
# define STRCPY strcpy
|
|
# define IFSTPCPY(X,...)
|
|
#endif
|
|
|
|
/* Core algorithm:
|
|
|
|
For each 16-byte chunk we calculate a 64-bit syndrome value with four bits
|
|
per byte. For even bytes, bits 0-3 are set if the relevant byte matched the
|
|
requested character or the byte is NUL. Bits 4-7 must be zero. Bits 4-7 are
|
|
set likewise for odd bytes so that adjacent bytes can be merged. Since the
|
|
bits in the syndrome reflect the order in which things occur in the original
|
|
string, counting trailing zeros identifies exactly which byte matched. */
|
|
|
|
ENTRY (STRCPY)
|
|
PTR_ARG (0)
|
|
PTR_ARG (1)
|
|
bic src, srcin, 15
|
|
mov wtmp, 0xf00f
|
|
ld1 {vdata.16b}, [src]
|
|
dup vrepmask.8h, wtmp
|
|
cmeq vhas_nul.16b, vdata.16b, 0
|
|
lsl shift, srcin, 2
|
|
and vhas_nul.16b, vhas_nul.16b, vrepmask.16b
|
|
addp vend.16b, vhas_nul.16b, vhas_nul.16b
|
|
fmov synd, dend
|
|
lsr synd, synd, shift
|
|
cbnz synd, L(tail)
|
|
|
|
ldr dataq, [src, 16]!
|
|
cmeq vhas_nul.16b, vdata.16b, 0
|
|
and vhas_nul.16b, vhas_nul.16b, vrepmask.16b
|
|
addp vend.16b, vhas_nul.16b, vhas_nul.16b
|
|
fmov synd, dend
|
|
cbz synd, L(start_loop)
|
|
|
|
#ifndef __AARCH64EB__
|
|
rbit synd, synd
|
|
#endif
|
|
sub tmp, src, srcin
|
|
clz len, synd
|
|
add len, tmp, len, lsr 2
|
|
tbz len, 4, L(less16)
|
|
sub tmp, len, 15
|
|
ldr dataq, [srcin]
|
|
ldr dataq2, [srcin, tmp]
|
|
str dataq, [dstin]
|
|
str dataq2, [dstin, tmp]
|
|
IFSTPCPY (add result, dstin, len)
|
|
ret
|
|
|
|
.p2align 4,,8
|
|
L(tail):
|
|
rbit synd, synd
|
|
clz len, synd
|
|
lsr len, len, 2
|
|
|
|
.p2align 4
|
|
L(less16):
|
|
tbz len, 3, L(less8)
|
|
sub tmp, len, 7
|
|
ldr data1, [srcin]
|
|
ldr data2, [srcin, tmp]
|
|
str data1, [dstin]
|
|
str data2, [dstin, tmp]
|
|
IFSTPCPY (add result, dstin, len)
|
|
ret
|
|
|
|
.p2align 4
|
|
L(less8):
|
|
subs tmp, len, 3
|
|
b.lo L(less4)
|
|
ldr dataw1, [srcin]
|
|
ldr dataw2, [srcin, tmp]
|
|
str dataw1, [dstin]
|
|
str dataw2, [dstin, tmp]
|
|
IFSTPCPY (add result, dstin, len)
|
|
ret
|
|
|
|
L(less4):
|
|
cbz len, L(zerobyte)
|
|
ldrh dataw1, [srcin]
|
|
strh dataw1, [dstin]
|
|
L(zerobyte):
|
|
strb wzr, [dstin, len]
|
|
IFSTPCPY (add result, dstin, len)
|
|
ret
|
|
|
|
.p2align 4
|
|
L(start_loop):
|
|
sub len, src, srcin
|
|
ldr dataq2, [srcin]
|
|
add dst, dstin, len
|
|
str dataq2, [dstin]
|
|
|
|
.p2align 5
|
|
L(loop):
|
|
str dataq, [dst], 16
|
|
ldr dataq, [src, 16]!
|
|
cmeq vhas_nul.16b, vdata.16b, 0
|
|
umaxp vend.16b, vhas_nul.16b, vhas_nul.16b
|
|
fmov synd, dend
|
|
cbz synd, L(loop)
|
|
|
|
and vhas_nul.16b, vhas_nul.16b, vrepmask.16b
|
|
addp vend.16b, vhas_nul.16b, vhas_nul.16b /* 128->64 */
|
|
fmov synd, dend
|
|
#ifndef __AARCH64EB__
|
|
rbit synd, synd
|
|
#endif
|
|
clz len, synd
|
|
lsr len, len, 2
|
|
sub tmp, len, 15
|
|
ldr dataq, [src, tmp]
|
|
str dataq, [dst, tmp]
|
|
IFSTPCPY (add result, dst, len)
|
|
ret
|
|
|
|
END (STRCPY)
|
|
|
|
#ifdef BUILD_STPCPY
|
|
weak_alias (__stpcpy, stpcpy)
|
|
libc_hidden_def (__stpcpy)
|
|
libc_hidden_builtin_def (stpcpy)
|
|
#else
|
|
libc_hidden_builtin_def (strcpy)
|
|
#endif
|