| /* memset/bzero -- set memory area to CH/0 |
| Highly optimized version for ix86, x>=6. |
| Copyright (C) 1999-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999. |
| |
| 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 */ |
| #ifdef USE_AS_BZERO |
| # define DEST PARMS |
| # define LEN DEST+4 |
| #else |
| # define RTN PARMS |
| # define DEST RTN |
| # define CHR DEST+4 |
| # define LEN CHR+4 |
| #endif |
| |
| .text |
| #if defined SHARED && IS_IN (libc) && !defined USE_AS_BZERO |
| ENTRY_CHK (__memset_chk) |
| movl 12(%esp), %eax |
| cmpl %eax, 16(%esp) |
| jb HIDDEN_JUMPTARGET (__chk_fail) |
| END_CHK (__memset_chk) |
| #endif |
| ENTRY (memset) |
| |
| cld |
| pushl %edi |
| cfi_adjust_cfa_offset (4) |
| movl DEST(%esp), %edx |
| movl LEN(%esp), %ecx |
| #ifdef USE_AS_BZERO |
| xorl %eax, %eax /* fill with 0 */ |
| #else |
| movzbl CHR(%esp), %eax |
| #endif |
| jecxz 1f |
| movl %edx, %edi |
| cfi_rel_offset (edi, 0) |
| andl $3, %edx |
| jz 2f /* aligned */ |
| jp 3f /* misaligned at 3, store just one byte below */ |
| stosb /* misaligned at 1 or 2, store two bytes */ |
| decl %ecx |
| jz 1f |
| 3: stosb |
| decl %ecx |
| jz 1f |
| xorl $1, %edx |
| jnz 2f /* was misaligned at 2 or 3, now aligned */ |
| stosb /* was misaligned at 1, store third byte */ |
| decl %ecx |
| 2: movl %ecx, %edx |
| shrl $2, %ecx |
| andl $3, %edx |
| #ifndef USE_AS_BZERO |
| imul $0x01010101, %eax |
| #endif |
| rep |
| stosl |
| movl %edx, %ecx |
| rep |
| stosb |
| |
| 1: |
| #ifndef USE_AS_BZERO |
| movl DEST(%esp), %eax /* start address of destination is result */ |
| #endif |
| popl %edi |
| cfi_adjust_cfa_offset (-4) |
| cfi_restore (edi) |
| |
| ret |
| END (memset) |
| libc_hidden_builtin_def (memset) |
