38 lines
836 B
ArmAsm
38 lines
836 B
ArmAsm
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! _strncat() Author: Kees J. Bot
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! 27 Jan 1994
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.sect .text; .sect .rom; .sect .data; .sect .bss
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! char *_strncat(char *s1, const char *s2, size_t dx)
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! Append string s2 to s1.
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!
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.sect .text
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.define __strncat
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__strncat:
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push bp
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mov bp, sp
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push si
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push di
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mov di, 4(bp) ! String s1
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mov cx, #-1
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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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dec di ! Back one up (and clear 'Z' flag)
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push di ! Save end of s1
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mov di, 6(bp) ! di = string s2
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mov cx, dx ! Maximum count
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repne scasb ! Look for the end of s2
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jne no0
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inc cx ! Exclude null byte
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no0: sub dx, cx ! Number of bytes in s2
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mov cx, dx
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mov si, 6(bp) ! si = string s2
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pop di ! di = 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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mov ax, 4(bp) ! Return s1
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pop di
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pop si
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pop bp
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ret
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