forked from KolibriOS/kolibrios
49cb0f914d
devman: scan pci root bus git-svn-id: svn://kolibrios.org@1627 a494cfbc-eb01-0410-851d-a64ba20cac60
42 lines
923 B
ArmAsm
42 lines
923 B
ArmAsm
/* strchr() Author: Kees J. Bot */
|
|
/* 1 Jan 1994 */
|
|
|
|
/* char *strchr(const char *s, int c) */
|
|
/* Look for a character in a string. */
|
|
/* */
|
|
#include "asm.h"
|
|
|
|
ENTRY(strchr)
|
|
push %ebp
|
|
movl %esp, %ebp
|
|
push %edi
|
|
cld
|
|
movl 8(%ebp), %edi /* edi = string */
|
|
movl $16, %edx /* Look at small chunks of the string */
|
|
next:
|
|
shll $1, %edx /* Chunks become bigger each time */
|
|
movl %edx, %ecx
|
|
xorb %al, %al /* Look for the zero at the end */
|
|
|
|
repne scasb
|
|
pushf /* Remember the flags */
|
|
subl %edx, %ecx
|
|
negl %ecx /* Some or all of the chunk */
|
|
subl %ecx, %edi /* Step back */
|
|
movb 12(%ebp), %al /* The character to look for */
|
|
|
|
repne scasb
|
|
je found
|
|
popf /* Did we find the end of string earlier? */
|
|
jne next /* No, try again */
|
|
xorl %eax, %eax /* Return NULL */
|
|
pop %edi
|
|
pop %ebp
|
|
ret
|
|
found:
|
|
pop %eax /* Get rid of those flags */
|
|
leal -1(%edi), %eax /* Address of byte found */
|
|
pop %edi
|
|
pop %ebp
|
|
ret
|