41 lines
924 B
ArmAsm
41 lines
924 B
ArmAsm
/* _strncat() Author: Kees J. Bot */
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/* 1 Jan 1994 */
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/* char *_strncat(char *s1, const char *s2, size_t edx) */
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/* Append string s2 to s1. */
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/* */
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#include <machine/asm.h>
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ENTRY(_strncat)
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push %ebp
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movl %esp, %ebp
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push %esi
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push %edi
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movl 8(%ebp), %edi /* String s1 */
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movl $-1, %ecx
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xorb %al, %al /* Null byte */
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cld
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repne scasb /* Look for the zero byte in s1 */
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decl %edi /* Back one up (and clear 'Z' flag) */
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push %edi /* Save end of s1 */
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movl 12(%ebp), %edi /* edi = string s2 */
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movl %edx, %ecx /* Maximum count */
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repne scasb /* Look for the end of s2 */
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jne no0
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incl %ecx /* Exclude null byte */
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no0:
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subl %ecx, %edx /* Number of bytes in s2 */
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movl %edx, %ecx
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movl 12(%ebp), %esi /* esi = string s2 */
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pop %edi /* edi = end of string s1 */
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rep movsb /* Copy bytes */
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stosb /* Add a terminating null */
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movl 8(%ebp), %eax /* Return s1 */
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pop %edi
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pop %esi
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pop %ebp
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ret
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