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/*
* Name: string.h
* Description: asm/string.h from Linux, but everything except strnlen()
* and memscan() disabled.
* Modified: Christian Starkjohann <cs@hal.kph.tuwien.ac.at>
* Date: 1996-11-14
* Copyright: GNU-GPL
* Tabsize: 4
*/
#ifndef _I386_STRING_H_
#define _I386_STRING_H_
/*
* 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
*/
#ifdef ASM_FOR_NEXTSTEP /* we don't want any of these for now. */
#define __HAVE_ARCH_STRCPY
extern inline char * strcpy(char * dest,const char *src)
{
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRNCPY
extern inline char * strncpy(char * dest,const char *src,size_t count)
{
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRCAT
extern inline char * strcat(char * dest,const char * src)
{
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRNCAT
extern inline char * strncat(char * dest,const char * src,size_t count)
{
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRCMP
extern inline int strcmp(const char * cs,const char * ct)
{
register int __res;
__asm__ __volatile__(
"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:\tsbbl %%eax,%%eax\n\t"
"orb $1,%%eax\n"
"3:"
:"=a" (__res):"S" (cs),"D" (ct):"si","di");
return __res;
}
#define __HAVE_ARCH_STRNCMP
extern inline int strncmp(const char * cs,const char * ct,size_t count)
{
register int __res;
__asm__ __volatile__(
"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:\tsbbl %%eax,%%eax\n\t"
"orb $1,%%al\n"
"4:"
:"=a" (__res):"S" (cs),"D" (ct),"c" (count):"si","di","cx");
return __res;
}
#define __HAVE_ARCH_STRCHR
extern inline char * strchr(const char * s, int c)
{
register char * __res;
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRRCHR
extern inline char * strrchr(const char * s, int c)
{
register char * __res;
__asm__ __volatile__(
"cld\n\t"
"movb %%al,%%ah\n"
"1:\tlodsb\n\t"
"cmpb %%ah,%%al\n\t"
"jne 2f\n\t"
"leal -1(%%esi),%0\n"
"2:\ttestb %%al,%%al\n\t"
"jne 1b"
:"=d" (__res):"0" (0),"S" (s),"a" (c):"ax","si");
return __res;
}
#define __HAVE_ARCH_STRSPN
extern inline size_t strspn(const char * cs, const char * ct)
{
register char * __res;
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRCSPN
extern inline size_t strcspn(const char * cs, const char * ct)
{
register char * __res;
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRPBRK
extern inline char * strpbrk(const char * cs,const char * ct)
{
register char * __res;
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRSTR
extern inline char * strstr(const char * cs,const char * ct)
{
register char * __res;
__asm__ __volatile__(
"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;
}
#define __HAVE_ARCH_STRLEN
extern inline size_t strlen(const char * s)
{
register int __res;
__asm__ __volatile__(
"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;
}
#if 0 /* disable this, it seems to be broken on NEXTSTEP */
#define __HAVE_ARCH_STRTOK
extern inline char * strtok(char * s,const char * ct)
{
register char * __res;
__asm__ __volatile__(
"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 delimiter-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;
}
#endif
extern inline void * __memcpy(void * to, const void * from, size_t n)
{
__asm__ __volatile__(
"cld\n\t"
"rep ; movsl\n\t"
"testb $2,%b1\n\t"
"je 1f\n\t"
"movsw\n"
"1:\ttestb $1,%b1\n\t"
"je 2f\n\t"
"movsb\n"
"2:"
: /* no output */
:"c" (n/4), "q" (n),"D" ((long) to),"S" ((long) from)
: "cx","di","si","memory");
return (to);
}
/*
* This looks horribly ugly, but the compiler can optimize it totally,
* as the count is constant.
*/
extern inline void * __constant_memcpy(void * to, const void * from, size_t n)
{
switch (n) {
case 0:
return to;
case 1:
*(unsigned char *)to = *(const unsigned char *)from;
return to;
case 2:
*(unsigned short *)to = *(const unsigned short *)from;
return to;
case 3:
*(unsigned short *)to = *(const unsigned short *)from;
*(2+(unsigned char *)to) = *(2+(const unsigned char *)from);
return to;
case 4:
*(unsigned long *)to = *(const unsigned long *)from;
return to;
case 8:
*(unsigned long *)to = *(const unsigned long *)from;
*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
return to;
case 12:
*(unsigned long *)to = *(const unsigned long *)from;
*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
*(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
return to;
case 16:
*(unsigned long *)to = *(const unsigned long *)from;
*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
*(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
*(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
return to;
case 20:
*(unsigned long *)to = *(const unsigned long *)from;
*(1+(unsigned long *)to) = *(1+(const unsigned long *)from);
*(2+(unsigned long *)to) = *(2+(const unsigned long *)from);
*(3+(unsigned long *)to) = *(3+(const unsigned long *)from);
*(4+(unsigned long *)to) = *(4+(const unsigned long *)from);
return to;
}
#define COMMON(x) \
__asm__("cld\n\t" \
"rep ; movsl" \
x \
: /* no outputs */ \
: "c" (n/4),"D" ((long) to),"S" ((long) from) \
: "cx","di","si","memory");
switch (n % 4) {
case 0: COMMON(""); return to;
case 1: COMMON("\n\tmovsb"); return to;
case 2: COMMON("\n\tmovsw"); return to;
case 3: COMMON("\n\tmovsw\n\tmovsb"); return to;
}
#undef COMMON
}
#if 0 /* CS: think, this may cause some troubles... */
#define __HAVE_ARCH_MEMCPY
#define memcpy(t, f, n) \
(__builtin_constant_p(n) ? \
__constant_memcpy((t),(f),(n)) : \
__memcpy((t),(f),(n)))
#endif
#define __HAVE_ARCH_MEMMOVE
extern inline void * memmove(void * dest,const void * src, size_t n)
{
if (dest<src)
__asm__ __volatile__(
"cld\n\t"
"rep\n\t"
"movsb"
: /* no output */
:"c" (n),"S" (src),"D" (dest)
:"cx","si","di");
else
__asm__ __volatile__(
"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;
}
#define memcmp __builtin_memcmp
#define __HAVE_ARCH_MEMCHR
extern inline void * memchr(const void * cs,int c,size_t count)
{
register void * __res;
if (!count)
return NULL;
__asm__ __volatile__(
"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_generic(void * s, char c,size_t count)
{
__asm__ __volatile__(
"cld\n\t"
"rep\n\t"
"stosb"
: /* no output */
:"a" (c),"D" (s),"c" (count)
:"cx","di","memory");
return s;
}
/* we might want to write optimized versions of these later */
#define __constant_count_memset(s,c,count) __memset_generic((s),(c),(count))
/*
* memset(x,0,y) is a reasonably common thing to do, so we want to fill
* things 32 bits at a time even when we don't know the size of the
* area at compile-time..
*/
extern inline void * __constant_c_memset(void * s, unsigned long c, size_t count)
{
__asm__ __volatile__(
"cld\n\t"
"rep ; stosl\n\t"
"testb $2,%b1\n\t"
"je 1f\n\t"
"stosw\n"
"1:\ttestb $1,%b1\n\t"
"je 2f\n\t"
"stosb\n"
"2:"
: /* no output */
:"a" (c), "q" (count), "c" (count/4), "D" ((long) s)
:"cx","di","memory");
return (s);
}
/*
* This looks horribly ugly, but the compiler can optimize it totally,
* as we by now know that both pattern and count is constant..
*/
extern inline void * __constant_c_and_count_memset(void * s, unsigned long pattern, size_t count)
{
switch (count) {
case 0:
return s;
case 1:
*(unsigned char *)s = pattern;
return s;
case 2:
*(unsigned short *)s = pattern;
return s;
case 3:
*(unsigned short *)s = pattern;
*(2+(unsigned char *)s) = pattern;
return s;
case 4:
*(unsigned long *)s = pattern;
return s;
}
#define COMMON(x) \
__asm__("cld\n\t" \
"rep ; stosl" \
x \
: /* no outputs */ \
: "a" (pattern),"c" (count/4),"D" ((long) s) \
: "cx","di","memory")
switch (count % 4) {
case 0: COMMON(""); return s;
case 1: COMMON("\n\tstosb"); return s;
case 2: COMMON("\n\tstosw"); return s;
case 3: COMMON("\n\tstosw\n\tstosb"); return s;
}
#undef COMMON
}
#define __constant_c_x_memset(s, c, count) \
(__builtin_constant_p(count) ? \
__constant_c_and_count_memset((s),(c),(count)) : \
__constant_c_memset((s),(c),(count)))
#define __memset(s, c, count) \
(__builtin_constant_p(count) ? \
__constant_count_memset((s),(c),(count)) : \
__memset_generic((s),(c),(count)))
#define __HAVE_ARCH_MEMSET
#define memset(s, c, count) \
(__builtin_constant_p(c) ? \
__constant_c_x_memset((s),(0x01010101UL*(unsigned char)c),(count)) : \
__memset((s),(c),(count)))
#endif /* ASM_FOR_NEXTSTEP */
/* Added by Gertjan van Wingerde to make minix and sysv module work */
#define __HAVE_ARCH_STRNLEN
extern inline size_t strnlen(const char * s, size_t count)
{
register int __res;
__asm__ __volatile__(
"movl %1,%0\n\t"
"jmp 2f\n"
"1:\tcmpb $0,(%0)\n\t"
"je 3f\n\t"
"incl %0\n"
"2:\tdecl %2\n\t"
"cmpl $-1,%2\n\t"
"jne 1b\n"
"3:\tsubl %1,%0"
:"=a" (__res):"c" (s),"d" (count));
return __res;
}
/* end of additional stuff */
/*
* find the first occurrence of byte 'c', or 1 past the area if none
*/
#define __HAVE_ARCH_MEMSCAN
extern inline void * memscan(void * addr, int c, size_t size)
{
if (!size)
return addr;
__asm__("cld
repnz; scasb
jnz 1f
dec %%edi
1: "
: "=D" (addr), "=c" (size)
: "0" (addr), "1" (size), "a" (c));
return addr;
}
#endif
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.