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Diffstat (limited to 'sysdeps/i386/memcmp.S')
| -rw-r--r-- | sysdeps/i386/memcmp.S | 73 |
1 files changed, 0 insertions, 73 deletions
diff --git a/sysdeps/i386/memcmp.S b/sysdeps/i386/memcmp.S deleted file mode 100644 index 01f8f8ef03..0000000000 --- a/sysdeps/i386/memcmp.S +++ /dev/null @@ -1,73 +0,0 @@ -/* Compare two memory blocks for differences in the first COUNT bytes. - Copyright (C) 1995-2017 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" - -#define PARMS 4+4 /* space for 1 saved reg */ -#define BLK1 PARMS -#define BLK2 BLK1+4 -#define LEN BLK2+4 - - .text -ENTRY (memcmp) - - pushl %esi /* Save callee-safe registers. */ - cfi_adjust_cfa_offset (4) - movl %edi, %edx /* Note that %edx is not used and can - so be used to save %edi. It's faster. */ - cfi_register (edi, edx) - - movl BLK1(%esp), %esi - cfi_rel_offset (esi, 0) - movl BLK2(%esp), %edi - movl LEN(%esp), %ecx - - cld /* Set direction of comparison. */ - - xorl %eax, %eax /* Default result. */ - - repe /* Compare at most %ecx bytes. */ - cmpsb - jz L(1) /* If even last byte was equal we return 0. */ - - /* The memory blocks are not equal. So result of the last - subtraction is present in the carry flag. It is set when - the byte in block #2 is bigger. In this case we have to - return -1 (=0xffffffff), else 1. */ - sbbl %eax, %eax /* This is tricky. %eax == 0 and carry is set - or not depending on last subtraction. */ - - /* At this point %eax == 0, if the byte of block #1 was bigger, and - 0xffffffff if the last byte of block #2 was bigger. The latter - case is already correct but the former needs a little adjustment. - Note that the following operation does not change 0xffffffff. */ - orb $1, %al /* Change 0 to 1. */ - -L(1): popl %esi /* Restore registers. */ - cfi_adjust_cfa_offset (-4) - cfi_restore (esi) - movl %edx, %edi - cfi_restore (edi) - - ret -END (memcmp) - -#undef bcmp -weak_alias (memcmp, bcmp) -libc_hidden_builtin_def (memcmp) |