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-rw-r--r--sysdeps/i386/memcpy.S95
1 files changed, 95 insertions, 0 deletions
diff --git a/sysdeps/i386/memcpy.S b/sysdeps/i386/memcpy.S
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+++ b/sysdeps/i386/memcpy.S
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+/* memcpy with REP MOVSB/STOSB
+ Copyright (C) 2015-2016 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