string.c

SimpleGraphicOperatingSystem 32位图形化操作系统 多进程 支持FAT32 详见www.sgos.net.cn

#include <Osdef.h>
#include <ctype.h>
#include <string.h>

/*
 * Note: Some are from Linux0.11 Source Code, But changed.
 */

char * strerror(int errno);

EXPORT char * strcpy(char * dest,const char *src)
{
__asm__("cld\n"
    "1:\tlodsb\n\t"
    "stosb\n\t"
    "testb %%al,%%al\n\t"
    "jne 1b"
    ::"S" (src),"D" (dest));
return dest;
}

EXPORT char * strncpy(char * dest,const char *src,int count)
{
__asm__("cld\n"
    "1:\tdecl %2\n\t"
    "js 2f\n\t"
    "lodsb\n\t"
    "stosb\n\t"
    "testb %%al,%%al\n\t"
    "jne 1b\n\t"
    "rep\n\t"
    "stosb\n"
    "2:"
    ::"S" (src),"D" (dest),"c" (count));
return dest;
}

EXPORT char * strcat(char * dest,const char * src)
{
__asm__("cld\n\t"
    "repne\n\t"
    "scasb\n\t"
    "decl %1\n"
    "1:\tlodsb\n\t"
    "stosb\n\t"
    "testb %%al,%%al\n\t"
    "jne 1b"
    ::"S" (src),"D" (dest),"a" (0),"c" (0xffffffff));
return dest;
}

EXPORT char * strncat(char * dest,const char * src,int count)
{
__asm__("cld\n\t"
    "repne\n\t"
    "scasb\n\t"
    "decl %1\n\t"
    "movl %4,%3\n"
    "1:\tdecl %3\n\t"
    "js 2f\n\t"
    "lodsb\n\t"
    "stosb\n\t"
    "testb %%al,%%al\n\t"
    "jne 1b\n"
    "2:\txorl %2,%2\n\t"
    "stosb"
    ::"S" (src),"D" (dest),"a" (0),"c" (0xffffffff),"g" (count)
    );
return dest;
}

EXPORT int strcmp(const char * cs,const char * ct)
{
register int __res __asm__("ax");
__asm__("cld\n"
    "1:\tlodsb\n\t"
    "scasb\n\t"
    "jne 2f\n\t"
    "testb %%al,%%al\n\t"
    "jne 1b\n\t"
    "xorl %%eax,%%eax\n\t"
    "jmp 3f\n"
    "2:\tmovl $1,%%eax\n\t"
    "jl 3f\n\t"
    "negl %%eax\n"
    "3:"
    :"=a" (__res):"D" (cs),"S" (ct));
return __res;
}

EXPORT int strncmp(const char * cs,const char * ct,int count)
{
register int __res __asm__("ax");
__asm__("cld\n"
    "1:\tdecl %3\n\t"
    "js 2f\n\t"
    "lodsb\n\t"
    "scasb\n\t"
    "jne 3f\n\t"
    "testb %%al,%%al\n\t"
    "jne 1b\n"
    "2:\txorl %%eax,%%eax\n\t"
    "jmp 4f\n"
    "3:\tmovl $1,%%eax\n\t"
    "jl 4f\n\t"
    "negl %%eax\n"
    "4:"
    :"=a" (__res):"D" (cs),"S" (ct),"c" (count));
return __res;
}

EXPORT char * strchr(const char * s,char c)
{
register char * __res __asm__("ax");
__asm__("cld\n\t"
    "movb %%al,%%ah\n"
    "1:\tlodsb\n\t"
    "cmpb %%ah,%%al\n\t"
    "je 2f\n\t"
    "testb %%al,%%al\n\t"
    "jne 1b\n\t"
    "movl $1,%1\n"
    "2:\tmovl %1,%0\n\t"
    "decl %0"
    :"=a" (__res):"S" (s),"0" (c));
return __res;
}

EXPORT char * strrchr(const char * s,char c)
{
register char * __res __asm__("dx");
__asm__("cld\n\t"
    "movb %%al,%%ah\n"
    "1:\tlodsb\n\t"
    "cmpb %%ah,%%al\n\t"
    "jne 2f\n\t"
    "movl %%esi,%0\n\t"
    "decl %0\n"
    "2:\ttestb %%al,%%al\n\t"
    "jne 1b"
    :"=d" (__res):"0" (0),"S" (s),"a" (c));
return __res;
}

EXPORT int strspn(const char * cs, const char * ct)
{
register char * __res __asm__("si");
__asm__("cld\n\t"
    "movl %4,%%edi\n\t"
    "repne\n\t"
    "scasb\n\t"
    "notl %%ecx\n\t"
    "decl %%ecx\n\t"
    "movl %%ecx,%%edx\n"
    "1:\tlodsb\n\t"
    "testb %%al,%%al\n\t"
    "je 2f\n\t"
    "movl %4,%%edi\n\t"
    "movl %%edx,%%ecx\n\t"
    "repne\n\t"
    "scasb\n\t"
    "je 1b\n"
    "2:\tdecl %0"
    :"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct));
return __res-cs;
}

EXPORT int strcspn(const char * cs, const char * ct)
{
register char * __res __asm__("si");
__asm__("cld\n\t"
    "movl %4,%%edi\n\t"
    "repne\n\t"
    "scasb\n\t"
    "notl %%ecx\n\t"
    "decl %%ecx\n\t"
    "movl %%ecx,%%edx\n"
    "1:\tlodsb\n\t"
    "testb %%al,%%al\n\t"
    "je 2f\n\t"
    "movl %4,%%edi\n\t"
    "movl %%edx,%%ecx\n\t"
    "repne\n\t"
    "scasb\n\t"
    "jne 1b\n"
    "2:\tdecl %0"
    :"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct));
return __res-cs;
}

EXPORT char * strpbrk(const char * cs,const char * ct)
{
register char * __res __asm__("si");
__asm__("cld\n\t"
    "movl %4,%%edi\n\t"
    "repne\n\t"
    "scasb\n\t"
    "notl %%ecx\n\t"
    "decl %%ecx\n\t"
    "movl %%ecx,%%edx\n"
    "1:\tlodsb\n\t"
    "testb %%al,%%al\n\t"
    "je 2f\n\t"
    "movl %4,%%edi\n\t"
    "movl %%edx,%%ecx\n\t"
    "repne\n\t"
    "scasb\n\t"
    "jne 1b\n\t"
    "decl %0\n\t"
    "jmp 3f\n"
    "2:\txorl %0,%0\n"
    "3:"
    :"=S" (__res):"a" (0),"c" (0xffffffff),"0" (cs),"g" (ct));
return __res;
}

EXPORT char * strstr(const char * cs,const char * ct)
{
register char * __res __asm__("ax");
__asm__("cld\n\t" \
    "movl %4,%%edi\n\t"
    "repne\n\t"
    "scasb\n\t"
    "notl %%ecx\n\t"
    "decl %%ecx\n\t"    /* NOTE! This also sets Z if searchstring='' */
    "movl %%ecx,%%edx\n"
    "1:\tmovl %4,%%edi\n\t"
    "movl %%esi,%%eax\n\t"
    "movl %%edx,%%ecx\n\t"
    "repe\n\t"
    "cmpsb\n\t"
    "je 2f\n\t"     /* also works for empty string, see above */
    "xchgl %%eax,%%esi\n\t"
    "incl %%esi\n\t"
    "cmpb $0,-1(%%eax)\n\t"
    "jne 1b\n\t"
    "xorl %%eax,%%eax\n\t"
    "2:"
    :"=a" (__res):"0" (0),"c" (0xffffffff),"S" (cs),"g" (ct));
return __res;
}

EXPORT int strlen(const char * s)
{
    int i=0;
    while(s[i]) i++;
    return i;
}

char * ___strtok;

EXPORT char * strtok(char * s,const char * ct)
{
register char * __res;
__asm__("testl %1,%1\n\t"
    "jne 1f\n\t"
    "testl %0,%0\n\t"
    "je 8f\n\t"
    "movl %0,%1\n"
    "1:\txorl %0,%0\n\t"
    "movl $-1,%%ecx\n\t"
    "xorl %%eax,%%eax\n\t"
    "cld\n\t"
    "movl %4,%%edi\n\t"
    "repne\n\t"
    "scasb\n\t"
    "notl %%ecx\n\t"
    "decl %%ecx\n\t"
    "je 7f\n\t"         /* empty delimeter-string */
    "movl %%ecx,%%edx\n"
    "2:\tlodsb\n\t"
    "testb %%al,%%al\n\t"
    "je 7f\n\t"
    "movl %4,%%edi\n\t"
    "movl %%edx,%%ecx\n\t"
    "repne\n\t"
    "scasb\n\t"
    "je 2b\n\t"
    "decl %1\n\t"
    "cmpb $0,(%1)\n\t"
    "je 7f\n\t"
    "movl %1,%0\n"
    "3:\tlodsb\n\t"
    "testb %%al,%%al\n\t"
    "je 5f\n\t"
    "movl %4,%%edi\n\t"
    "movl %%edx,%%ecx\n\t"
    "repne\n\t"
    "scasb\n\t"
    "jne 3b\n\t"
    "decl %1\n\t"
    "cmpb $0,(%1)\n\t"
    "je 5f\n\t"
    "movb $0,(%1)\n\t"
    "incl %1\n\t"
    "jmp 6f\n"
    "5:\txorl %1,%1\n"
    "6:\tcmpb $0,(%0)\n\t"
    "jne 7f\n\t"
    "xorl %0,%0\n"
    "7:\ttestl %0,%0\n\t"
    "jne 8f\n\t"
    "movl %0,%1\n"
    "8:"
    :"=b" (__res),"=S" (___strtok)
    :"0" (___strtok),"1" (s),"g" (ct));
return __res;
}

EXPORT void * memcpy(void * dest,const void * src, int n)
{
__asm__("cld\n\t"
    "rep\n\t"
    "movsb"
    ::"c" (n),"S" (src),"D" (dest));
return dest;
}

EXPORT void * memcpyw(void * dest,const void * src, int n)
{
__asm__("cld\n\t"
    "rep\n\t"
    "movsw"
    ::"c" (n),"S" (src),"D" (dest));
return dest;
}

EXPORT char * memmove(char * dest,const char * src, int n)
{
if (dest<src)
__asm__("cld\n\t"
    "rep\n\t"
    "movsb"
    ::"c" (n),"S" (src),"D" (dest));
else
__asm__("std\n\t"
    "rep\n\t"
    "movsb"
    ::"c" (n),"S" (src+n-1),"D" (dest+n-1));
return dest;
}

EXPORT int memcmp(const void * cs,const void * ct,int count)
{
register int __res __asm__("ax");
__asm__("cld\n\t"
    "repe\n\t"
    "cmpsb\n\t"
    "je 1f\n\t"
    "movl $1,%%eax\n\t"
    "jl 1f\n\t"
    "negl %%eax\n"
    "1:"
    :"=a" (__res):"0" (0),"D" (cs),"S" (ct),"c" (count));
return __res;
}

EXPORT void * memchr(const void * cs,char c,int count)
{
register void * __res __asm__("di");
if (!count)
    return NULL;
__asm__("cld\n\t"
    "repne\n\t"
    "scasb\n\t"
    "je 1f\n\t"
    "movl $1,%0\n"
    "1:\tdecl %0"
    :"=D" (__res):"a" (c),"D" (cs),"c" (count));
return __res;
}

EXPORT void * memset(void * s,char c,int count)
{
__asm__("cld\n\t"
    "rep\n\t"
    "stosb"
    ::"a" (c),"D" (s),"c" (count));
return s;
}

EXPORT void * memsetw(void * s,short n,int count)
{
__asm__("cld\n\t"
    "rep\n\t"
    "stosw"
    ::"a" (n),"D" (s),"c" (count));
return s;
}

EXPORT char * strlwr(char * str)
{
    int i=0;
    while(str[i++])
        if( str[i]>='A' && str[i]<='Z' )
            str[i]-='A'-'a';
    return str;
}

EXPORT int CompStrNoCaseN(char* s1, char* s2, int len)
{
    int i;
    for(i=0;s1[i] && s2[i];i++)
    {
        register char c = tolower(s1[i]);
        if( c!=tolower(s2[i]) )
            return 0;
    }
    if( (!s1[i] && !s2[i])||(i>len) )
        return 1;
    else{
        return 0;
    }
}

EXPORT int CompStrNoCase(char* s1, char* s2)
{
    int i;
    for(i=0;s1[i] && s2[i];i++)
    {
        register char c = tolower(s1[i]);
        if( c!=tolower(s2[i]) )
            return 0;
    }
    if( (!s1[i] && !s2[i]) )
        return 1;
    else 
        return 0;
}