31 lines
559 B
ArmAsm
31 lines
559 B
ArmAsm
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! memchr() Author: Kees J. Bot
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! 2 Jan 1994
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.sect .text; .sect .rom; .sect .data; .sect .bss
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! void *memchr(const void *s, int c, size_t n)
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! Look for a character in a chunk of memory.
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!
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.sect .text
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.define _memchr
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.align 16
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_memchr:
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push ebp
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mov ebp, esp
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push edi
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mov edi, 8(ebp) ! edi = string
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movb al, 12(ebp) ! The character to look for
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mov ecx, 16(ebp) ! Length
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cmpb cl, 1 ! 'Z' bit must be clear if ecx = 0
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cld
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repne
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scasb
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jne failure
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lea eax, -1(edi) ! Found
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pop edi
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pop ebp
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ret
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failure:xor eax, eax
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pop edi
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pop ebp
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ret
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