/*
 *  linux/include/linux/string.h
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file README.legal in the main directory of this archive
 * for more details.
 */

#ifndef _LINUX_STRING_H_
#define _LINUX_STRING_H_

#include <linux/types.h>	/* for size_t */

#ifndef NULL
#define NULL ((void *) 0)
#endif

#if defined(__i386__)

/*
 * This string-include defines all string functions as inline
 * functions. Use gcc. It also assumes ds=es=data space, this should be
 * normal. Most of the string-functions are rather heavily hand-optimized,
 * see especially strtok,strstr,str[c]spn. They should work, but are not
 * very easy to understand. Everything is done entirely within the register
 * set, making the functions fast and clean. String instructions have been
 * used through-out, making for "slightly" unclear code :-)
 *
 *		Copyright (C) 1991, 1992 Linus Torvalds
 */
 
extern inline char * strcpy(char * dest,const char *src)
{
__asm__("cld\n"
	"1:\tlodsb\n\t"
	"stosb\n\t"
	"testb %%al,%%al\n\t"
	"jne 1b"
	: /* no output */
	:"S" (src),"D" (dest):"si","di","ax","memory");
return dest;
}

extern inline char * strncpy(char * dest,const char *src,size_t 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:"
	: /* no output */
	:"S" (src),"D" (dest),"c" (count):"si","di","ax","cx","memory");
return dest;
}

extern inline 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"
	: /* no output */
	:"S" (src),"D" (dest),"a" (0),"c" (0xffffffff):"si","di","ax","cx");
return dest;
}

extern inline char * strncat(char * dest,const char * src,size_t 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"
	: /* no output */
	:"S" (src),"D" (dest),"a" (0),"c" (0xffffffff),"g" (count)
	:"si","di","ax","cx","memory");
return dest;
}

extern inline 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"
	"jb 3f\n\t"
	"negl %%eax\n"
	"3:"
	:"=a" (__res):"D" (cs),"S" (ct):"si","di");
return __res;
}

extern inline int strncmp(const char * cs,const char * ct,size_t 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"
	"jb 4f\n\t"
	"negl %%eax\n"
	"4:"
	:"=a" (__res):"D" (cs),"S" (ct),"c" (count):"si","di","cx");
return __res;
}

extern inline 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):"si");
return __res;
}

extern inline 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):"ax","si");
return __res;
}

extern inline size_t 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)
	:"ax","cx","dx","di");
return __res-cs;
}

extern inline size_t 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)
	:"ax","cx","dx","di");
return __res-cs;
}

extern inline 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)
	:"ax","cx","dx","di");
return __res;
}

extern inline 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)
	:"cx","dx","di","si");
return __res;
}

extern inline size_t strlen(const char * s)
{
register int __res __asm__("cx");
__asm__("cld\n\t"
	"repne\n\t"
	"scasb\n\t"
	"notl %0\n\t"
	"decl %0"
	:"=c" (__res):"D" (s),"a" (0),"0" (0xffffffff):"di");
return __res;
}

extern char * ___strtok;

extern inline 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)
	:"ax","cx","dx","di","memory");
return __res;
}

extern inline void * memcpy(void * to, const void * from, size_t n)
{
__asm__("cld\n\t"
	"movl %%edx, %%ecx\n\t"
	"shrl $2,%%ecx\n\t"
	"rep ; movsl\n\t"
	"testb $1,%%dl\n\t"
	"je 1f\n\t"
	"movsb\n"
	"1:\ttestb $2,%%dl\n\t"
	"je 2f\n\t"
	"movsw\n"
	"2:\n"
	: /* no output */
	:"d" (n),"D" ((long) to),"S" ((long) from)
	: "cx","di","si","memory");
return (to);
}

extern inline void * memmove(void * dest,const void * src, size_t n)
{
if (dest<src)
__asm__("cld\n\t"
	"rep\n\t"
	"movsb"
	: /* no output */
	:"c" (n),"S" (src),"D" (dest)
	:"cx","si","di");
else
__asm__("std\n\t"
	"rep\n\t"
	"movsb\n\t"
	"cld"
	: /* no output */
	:"c" (n),
	 "S" (n-1+(const char *)src),
	 "D" (n-1+(char *)dest)
	:"cx","si","di","memory");
return dest;
}

extern inline int memcmp(const void * cs,const void * ct,size_t 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"
	"jb 1f\n\t"
	"negl %%eax\n"
	"1:"
	:"=a" (__res):"0" (0),"D" (cs),"S" (ct),"c" (count)
	:"si","di","cx");
return __res;
}

extern inline void * memchr(const void * cs,char c,size_t 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)
	:"cx");
return __res;
}

extern inline void * memset(void * s,char c,size_t count)
{
__asm__("cld\n\t"
	"rep\n\t"
	"stosb"
	: /* no output */
	:"a" (c),"D" (s),"c" (count)
	:"cx","di","memory");
return s;
}

#elif defined (__mc68000__)

extern inline char * strcpy(char * dest,const char *src)
{
  char *xdest = dest;

  __asm__ __volatile__
       ("1:\tmoveb %1@+,%0@+\n\t"
        "bne 1b"
	: "=a" (dest), "=a" (src)
        : "0" (dest), "1" (src) : "memory");
  return xdest;
}

extern inline void * strncpy(char *dest, const void *src, size_t n)
{
  char *xdest = dest;

  if (n == 0)
    return xdest;

  __asm__
       ("1:\tmoveb %1@+,%0@+\n\t"
	"beq 2f\n\t"
        "subql #1,%3\n\t"
        "bne 1b\n\t"
        "2:"
        : "=a" (dest), "=a" (src), "=d" (n)
        : "0" (dest), "1" (src), "2" (n)
        : "memory");
return dest;
}

extern inline char * strcat(char * dest, const char * src)
{
	char *tmp = dest;

	while (*dest)
		dest++;
	while ((*dest++ = *src++))
		;

	return tmp;
}

extern inline char * strncat(char *dest, const char *src, size_t count)
{
	char *tmp = dest;

	if (count) {
		while (*dest)
			dest++;
		while ((*dest++ = *src++)) {
			if (--count == 0)
				break;
		}
	}

	return tmp;
}

extern inline int strcmp(const char * cs,const char * ct)
{
  char __res;

  __asm__
       ("1:\tmoveb %0@+,%2\n\t" /* get *cs */
        "cmpb %1@+,%2\n\t"      /* compare a byte */
        "bne  2f\n\t"           /* not equal, break out */
        "tstb %2\n\t"           /* at end of cs? */
        "bne  1b\n\t"           /* no, keep going */
        "bra  3f\n\t"		/* strings are equal */
        "2:\tsubb %1@-,%2\n\t"  /* *cs - *ct */
        "3:"
        : "=a" (cs), "=a" (ct), "=d" (__res)
        : "0" (cs), "1" (ct));
  return __res;
}

extern inline int strncmp(const char * cs,const char * ct,size_t count)
{
  char __res;

  if (!count)
    return 0;
  __asm__
       ("1:\tmovb %0@+,%3\n\t"          /* get *cs */
        "cmpb   %1@+,%3\n\t"            /* compare a byte */
        "bne    3f\n\t"                 /* not equal, break out */
        "tstb   %3\n\t"                 /* at end of cs? */
        "beq    4f\n\t"                 /* yes, all done */
        "subql  #1,%2\n\t"              /* no, adjust count */
        "bne    1b\n\t"                 /* more to do, keep going */
        "2:\tmoveq #0,%3\n\t"           /* strings are equal */
        "bra    4f\n\t"
        "3:\tsubb %1@-,%3\n\t"          /* *cs - *ct */
        "4:"
        : "=a" (cs), "=a" (ct), "=d" (count), "=d" (__res)
        : "0" (cs), "1" (ct), "2" (count));
  return __res;
}

extern inline char * strchr(const char * s,char c)
{
  const char ch = c;
  
  for(; *s != ch; ++s)
    if (*s == '\0')
      return( NULL );
  return( (char *) s);
}

extern inline size_t strlen(const char * s)
{
  const char *sc;
  for (sc = s; *sc != '\0'; ++sc) ;
  return(sc - s);
}

extern inline size_t strspn(const char *s, const char *accept)
{
  const char *p;
  const char *a;
  size_t count = 0;

  for (p = s; *p != '\0'; ++p)
    {
      for (a = accept; *a != '\0'; ++a)
        if (*p == *a)
          break;
      if (*a == '\0')
        return count;
      else
        ++count;
    }

  return count;
}

extern inline char * strpbrk(const char * cs,const char * ct)
{
  const char *sc1,*sc2;
  
  for( sc1 = cs; *sc1 != '\0'; ++sc1)
    for( sc2 = ct; *sc2 != '\0'; ++sc2)
      if (*sc1 == *sc2)
	return((char *) sc1);
  return( NULL );
}

extern inline char * strtok(char * s,const char * ct)
{
  char *sbegin, *send;
  static char *ssave = NULL;
  
  sbegin  = s ? s : ssave;
  if (!sbegin) {
	  return NULL;
  }
  sbegin += strspn(sbegin,ct);
  if (*sbegin == '\0') {
    ssave = NULL;
    return( NULL );
  }
  send = strpbrk( sbegin, ct);
  if (send && *send != '\0')
    *send++ = '\0';
  ssave = send;
  return (sbegin);
}

extern inline void * memset(void * s,char c,size_t count)
{
  void *xs = s;

  if (!count)
    return xs;
  __asm__ __volatile__
       ("1:\tmoveb %3,%0@+\n\t"
	"subql #1,%1\n\t"
        "bne 1b"
	: "=a" (s), "=d" (count)
        : "0" (s), "d" (c), "1" (count)
	: "memory");
  return xs;
}

extern inline void * memcpy(void * to, const void * from, size_t n)
{
  void *xto = to;

  if (!n)
    return xto;
  __asm__ __volatile__
       ("1:\tmoveb %1@+,%0@+\n\t"
	"subql #1,%2\n\t"
        "bne 1b"
        : "=a" (to), "=a" (from), "=d" (n)
        : "0" (to), "1" (from), "2" (n)
        : "memory" );
  return xto;
}

extern inline void * memmove(void * dest,const void * src, size_t n)
{
  void *xdest = dest;

  if (!n)
    return xdest;

  if (dest < src)
    __asm__ __volatile__
       ("1:\tmoveb %1@+,%0@+\n\t"
	"subql #1,%2\n\t"
        "bne 1b"
        : "=a" (dest), "=a" (src), "=d" (n)
        : "0" (dest), "1" (src), "2" (n)
        : "memory" );
  else
    __asm__ __volatile__
       ("1:\tmoveb %1@-,%0@-\n\t"
	"subql #1,%2\n\t"
        "bne 1b"
        : "=a" (dest), "=a" (src), "=d" (n)
        : "0" (dest+n), "1" (src+n), "2" (n)
        : "memory" );
  return xdest;
}

extern inline int memcmp(const void * cs,const void * ct,size_t count)
{
  const unsigned char *su1, *su2;

  for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
    if (*su1 != *su2)
      return((*su1 < *su2) ? -1 : +1);
  return(0);
}

#endif

#endif /* _LINUX_STRING_H_ */