diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/i386/i686/memmove.S | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/sysdeps/i386/i686/memmove.S b/sysdeps/i386/i686/memmove.S new file mode 100644 index 0000000000..76fda405c1 --- /dev/null +++ b/sysdeps/i386/i686/memmove.S @@ -0,0 +1,94 @@ +/* Copy memory block and return pointer to beginning of destination block + For Intel 80x86, x>=6. + This file is part of the GNU C Library. + Copyright (C) 2003 Free Software Foundation, Inc. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 2003. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <sysdep.h> +#include "asm-syntax.h" +#include "bp-sym.h" +#include "bp-asm.h" + +#define PARMS LINKAGE+4 /* one spilled register */ +#define RTN PARMS +#define DEST RTN+RTN_SIZE +#define SRC DEST+PTR_SIZE +#define LEN SRC+PTR_SIZE + + .text +ENTRY (BP_SYM (memmove)) + ENTER + + pushl %edi + + movl LEN(%esp), %ecx + movl DEST(%esp), %edi + movl %esi, %edx + movl SRC(%esp), %esi + CHECK_BOUNDS_BOTH_WIDE (%edi, DEST(%esp), %ecx) + CHECK_BOUNDS_BOTH_WIDE (%esi, SRC(%esp), %ecx) + + movl %edi, %eax + subl %esi, %eax + cmpl %eax, %edi + jae 3f + + cld + shrl $1, %ecx + jnc 1f + movsb +1: shrl $1, %ecx + jnc 2f + movsw +2: rep + movsl + movl %edx, %esi + movl DEST(%esp), %eax + RETURN_BOUNDED_POINTER (DEST(%esp)) + + popl %edi + + LEAVE + RET_PTR + + /* Backward copying. */ +3: std + leal -1(%edi, %ecx), %edi + leal -1(%esi, %ecx), %esi + shrl $1, %ecx + jnc 1f + movsb +1: subl $1, %edi + subl $1, %esi + shrl $1, %ecx + jnc 2f + movsw +2: subl $2, %edi + subl $2, %esi + rep + movsl + movl %edx, %esi + movl DEST(%esp), %eax + RETURN_BOUNDED_POINTER (DEST(%esp)) + + cld + popl %edi + + LEAVE + RET_PTR +END (BP_SYM (memmove)) |