| 1,30 → 1,27 |
|---|
| # _strnlen() Author: Kees J. Bot 1 Jan 1994 |
| /* _strnlen() Author: Kees J. Bot */ |
| /* 1 Jan 1994 */ |
| |
| # size_t _strnlen(const char *s, size_t ecx) |
| # Return the length of a string. |
| /* size_t _strnlen(const char *s, size_t ecx) */ |
| /* Return the length of a string. */ |
| /* */ |
| #include "asm.h" |
| |
| .intel_syntax |
| ENTRY(_strnlen) |
| push %ebp |
| movl %esp, %ebp |
| push %edi |
| movl 8(%ebp), %edi /* edi = string */ |
| xorb %al, %al /* Look for a zero byte */ |
| movl %ecx, %edx /* Save maximum count */ |
| cmpb $1, %cl /* 'Z' bit must be clear if ecx = 0 */ |
| cld |
| |
| .globl __strnlen |
| |
| .text |
| .align 16 |
| __strnlen: |
| push ebp |
| mov ebp, esp |
| push edi |
| mov edi, [ebp+8] # edi = string |
| xorb al, al # Look for a zero byte |
| mov edx, ecx # Save maximum count |
| cmpb cl, 1 # 'Z' bit must be clear if ecx = 0 |
| cld |
| repne |
| scasb # Look for zero |
| repne scasb /* Look for zero */ |
| jne no0 |
| inc ecx # Don't count zero byte |
| incl %ecx /* Don't count zero byte */ |
| no0: |
| mov eax, edx |
| sub eax, ecx # Compute bytes scanned |
| pop edi |
| pop ebp |
| movl %edx, %eax |
| subl %ecx, %eax /* Compute bytes scanned */ |
| pop %edi |
| pop %ebp |
| ret |