31 lines
823 B
ArmAsm
31 lines
823 B
ArmAsm
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# _strnlen() Author: Kees J. Bot 1 Jan 1994
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# size_t _strnlen(const char *s, size_t ecx)
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# Return the length of a string.
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.intel_syntax
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.globl __strnlen
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.text
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.align 16
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__strnlen:
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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, [ebp+8] # edi = string
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xorb al, al # Look for a zero byte
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mov edx, ecx # Save maximum count
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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 # Look for zero
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jne no0
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inc ecx # Don't count zero byte
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no0:
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mov eax, edx
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sub eax, ecx # Compute bytes scanned
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pop edi
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pop ebp
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ret
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