2010-03-03 15:27:30 +01:00
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/* _strnlen() Author: Kees J. Bot */
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/* 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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/* */
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2010-08-17 18:44:07 +02:00
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#include <machine/asm.h>
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ENTRY(_strnlen)
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2010-03-03 15:27:30 +01:00
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push %ebp
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movl %esp, %ebp
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push %edi
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movl 8(%ebp), %edi /* edi = string */
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xorb %al, %al /* Look for a zero byte */
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movl %ecx, %edx /* Save maximum count */
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cmpb $1, %cl /* 'Z' bit must be clear if ecx = 0 */
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cld
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repne scasb /* Look for zero */
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jne no0
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incl %ecx /* Don't count zero byte */
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no0:
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movl %edx, %eax
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subl %ecx, %eax /* Compute bytes scanned */
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pop %edi
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pop %ebp
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ret
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