diff options
Diffstat (limited to 'sysdeps/i386/memcpy.S')
-rw-r--r-- | sysdeps/i386/memcpy.S | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/sysdeps/i386/memcpy.S b/sysdeps/i386/memcpy.S new file mode 100644 index 0000000000..5f0196ee50 --- /dev/null +++ b/sysdeps/i386/memcpy.S @@ -0,0 +1,95 @@ +/* memcpy with REP MOVSB/STOSB + Copyright (C) 2015 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/>. */ + +#include <sysdep.h> +#include "asm-syntax.h" + +#ifndef MEMCPY +# define MEMCPY memcpy +# define MEMCPY_CHK __memcpy_chk +#endif + +#ifdef USE_AS_BCOPY +# define STR2 12 +# define STR1 STR2+4 +# define N STR1+4 +#else +# define STR1 12 +# define STR2 STR1+4 +# define N STR2+4 +#endif + +#define CFI_PUSH(REG) \ + cfi_adjust_cfa_offset (4); \ + cfi_rel_offset (REG, 0) + +#define CFI_POP(REG) \ + cfi_adjust_cfa_offset (-4); \ + cfi_restore (REG) + +#define PUSH(REG) pushl REG; CFI_PUSH (REG) +#define POP(REG) popl REG; CFI_POP (REG) + + .text +#if defined SHARED && IS_IN (libc) && !defined USE_AS_BCOPY +ENTRY (MEMCPY_CHK) + movl 12(%esp), %eax + cmpl %eax, 16(%esp) + jb HIDDEN_JUMPTARGET (__chk_fail) +END (MEMCPY_CHK) +#endif +ENTRY (MEMCPY) + PUSH (%esi) + PUSH (%edi) + movl N(%esp), %ecx + movl STR1(%esp), %edi + movl STR2(%esp), %esi + mov %edi, %eax +#ifdef USE_AS_MEMPCPY + add %ecx, %eax +#endif + +#ifdef USE_AS_MEMMOVE + cmp %esi, %edi + ja L(copy_backward) + je L(bwd_write_0bytes) +#endif + + rep movsb + POP (%edi) + POP (%esi) + ret + +#ifdef USE_AS_MEMMOVE +L(copy_backward): + lea -1(%edi,%ecx), %edi + lea -1(%esi,%ecx), %esi + std + rep movsb + cld +L(bwd_write_0bytes): + POP (%edi) + POP (%esi) + ret +#endif + +END (MEMCPY) + +#ifndef USE_AS_BCOPY +libc_hidden_builtin_def (MEMCPY) +#endif |