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0f88a5c66e
The symbol is not present in current POSIX specification and compiler already generates memset call.
80 lines
2.0 KiB
ArmAsm
80 lines
2.0 KiB
ArmAsm
/* memset/bzero -- set memory area to CH/0
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Highly optimized version for ix86, x>=6.
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Copyright (C) 1999-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <sysdep.h>
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#include "asm-syntax.h"
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#define PARMS 4+4 /* space for 1 saved reg */
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#define RTN PARMS
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#define DEST RTN
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#define CHR DEST+4
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#define LEN CHR+4
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.text
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#if defined SHARED && IS_IN (libc)
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ENTRY_CHK (__memset_chk)
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movl 12(%esp), %eax
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cmpl %eax, 16(%esp)
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jb HIDDEN_JUMPTARGET (__chk_fail)
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END_CHK (__memset_chk)
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#endif
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ENTRY (memset)
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cld
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pushl %edi
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cfi_adjust_cfa_offset (4)
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movl DEST(%esp), %edx
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movl LEN(%esp), %ecx
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movzbl CHR(%esp), %eax
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jecxz 1f
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movl %edx, %edi
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cfi_rel_offset (edi, 0)
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andl $3, %edx
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jz 2f /* aligned */
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jp 3f /* misaligned at 3, store just one byte below */
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stosb /* misaligned at 1 or 2, store two bytes */
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decl %ecx
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jz 1f
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3: stosb
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decl %ecx
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jz 1f
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xorl $1, %edx
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jnz 2f /* was misaligned at 2 or 3, now aligned */
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stosb /* was misaligned at 1, store third byte */
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decl %ecx
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2: movl %ecx, %edx
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shrl $2, %ecx
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andl $3, %edx
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imul $0x01010101, %eax
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rep
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stosl
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movl %edx, %ecx
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rep
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stosb
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1:
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movl DEST(%esp), %eax /* start address of destination is result */
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popl %edi
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cfi_adjust_cfa_offset (-4)
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cfi_restore (edi)
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ret
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END (memset)
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libc_hidden_builtin_def (memset)
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