aboutsummaryrefslogtreecommitdiff
path: root/include/asm-i386/string.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-i386/string.h')
-rw-r--r--include/asm-i386/string.h449
1 files changed, 449 insertions, 0 deletions
diff --git a/include/asm-i386/string.h b/include/asm-i386/string.h
new file mode 100644
index 00000000000..1679983d053
--- /dev/null
+++ b/include/asm-i386/string.h
@@ -0,0 +1,449 @@
+#ifndef _I386_STRING_H_
+#define _I386_STRING_H_
+
+#ifdef __KERNEL__
+#include <linux/config.h>
+/*
+ * On a 486 or Pentium, we are better off not using the
+ * byte string operations. But on a 386 or a PPro the
+ * byte string ops are faster than doing it by hand
+ * (MUCH faster on a Pentium).
+ */
+
+/*
+ * 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 strsep,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 :-)
+ *
+ * NO Copyright (C) 1991, 1992 Linus Torvalds,
+ * consider these trivial functions to be PD.
+ */
+
+/* AK: in fact I bet it would be better to move this stuff all out of line.
+ */
+
+#define __HAVE_ARCH_STRCPY
+static inline char * strcpy(char * dest,const char *src)
+{
+int d0, d1, d2;
+__asm__ __volatile__(
+ "1:\tlodsb\n\t"
+ "stosb\n\t"
+ "testb %%al,%%al\n\t"
+ "jne 1b"
+ : "=&S" (d0), "=&D" (d1), "=&a" (d2)
+ :"0" (src),"1" (dest) : "memory");
+return dest;
+}
+
+#define __HAVE_ARCH_STRNCPY
+static inline char * strncpy(char * dest,const char *src,size_t count)
+{
+int d0, d1, d2, d3;
+__asm__ __volatile__(
+ "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" (d0), "=&D" (d1), "=&c" (d2), "=&a" (d3)
+ :"0" (src),"1" (dest),"2" (count) : "memory");
+return dest;
+}
+
+#define __HAVE_ARCH_STRCAT
+static inline char * strcat(char * dest,const char * src)
+{
+int d0, d1, d2, d3;
+__asm__ __volatile__(
+ "repne\n\t"
+ "scasb\n\t"
+ "decl %1\n"
+ "1:\tlodsb\n\t"
+ "stosb\n\t"
+ "testb %%al,%%al\n\t"
+ "jne 1b"
+ : "=&S" (d0), "=&D" (d1), "=&a" (d2), "=&c" (d3)
+ : "0" (src), "1" (dest), "2" (0), "3" (0xffffffffu):"memory");
+return dest;
+}
+
+#define __HAVE_ARCH_STRNCAT
+static inline char * strncat(char * dest,const char * src,size_t count)
+{
+int d0, d1, d2, d3;
+__asm__ __volatile__(
+ "repne\n\t"
+ "scasb\n\t"
+ "decl %1\n\t"
+ "movl %8,%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" (d0), "=&D" (d1), "=&a" (d2), "=&c" (d3)
+ : "0" (src),"1" (dest),"2" (0),"3" (0xffffffffu), "g" (count)
+ : "memory");
+return dest;
+}
+
+#define __HAVE_ARCH_STRCMP
+static inline int strcmp(const char * cs,const char * ct)
+{
+int d0, d1;
+register int __res;
+__asm__ __volatile__(
+ "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,%%al\n"
+ "3:"
+ :"=a" (__res), "=&S" (d0), "=&D" (d1)
+ :"1" (cs),"2" (ct));
+return __res;
+}
+
+#define __HAVE_ARCH_STRNCMP
+static inline int strncmp(const char * cs,const char * ct,size_t count)
+{
+register int __res;
+int d0, d1, d2;
+__asm__ __volatile__(
+ "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" (d0), "=&D" (d1), "=&c" (d2)
+ :"1" (cs),"2" (ct),"3" (count));
+return __res;
+}
+
+#define __HAVE_ARCH_STRCHR
+static inline char * strchr(const char * s, int c)
+{
+int d0;
+register char * __res;
+__asm__ __volatile__(
+ "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" (d0) : "1" (s),"0" (c));
+return __res;
+}
+
+#define __HAVE_ARCH_STRRCHR
+static inline char * strrchr(const char * s, int c)
+{
+int d0, d1;
+register char * __res;
+__asm__ __volatile__(
+ "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"
+ :"=g" (__res), "=&S" (d0), "=&a" (d1) :"0" (0),"1" (s),"2" (c));
+return __res;
+}
+
+#define __HAVE_ARCH_STRLEN
+static inline size_t strlen(const char * s)
+{
+int d0;
+register int __res;
+__asm__ __volatile__(
+ "repne\n\t"
+ "scasb\n\t"
+ "notl %0\n\t"
+ "decl %0"
+ :"=c" (__res), "=&D" (d0) :"1" (s),"a" (0), "0" (0xffffffffu));
+return __res;
+}
+
+static inline void * __memcpy(void * to, const void * from, size_t n)
+{
+int d0, d1, d2;
+__asm__ __volatile__(
+ "rep ; movsl\n\t"
+ "testb $2,%b4\n\t"
+ "je 1f\n\t"
+ "movsw\n"
+ "1:\ttestb $1,%b4\n\t"
+ "je 2f\n\t"
+ "movsb\n"
+ "2:"
+ : "=&c" (d0), "=&D" (d1), "=&S" (d2)
+ :"0" (n/4), "q" (n),"1" ((long) to),"2" ((long) from)
+ : "memory");
+return (to);
+}
+
+/*
+ * This looks horribly ugly, but the compiler can optimize it totally,
+ * as the count is constant.
+ */
+static inline void * __constant_memcpy(void * to, const void * from, size_t n)
+{
+ if (n <= 128)
+ return __builtin_memcpy(to, from, n);
+
+#define COMMON(x) \
+__asm__ __volatile__( \
+ "rep ; movsl" \
+ x \
+ : "=&c" (d0), "=&D" (d1), "=&S" (d2) \
+ : "0" (n/4),"1" ((long) to),"2" ((long) from) \
+ : "memory");
+{
+ int d0, d1, d2;
+ switch (n % 4) {
+ case 0: COMMON(""); return to;
+ case 1: COMMON("\n\tmovsb"); return to;
+ case 2: COMMON("\n\tmovsw"); return to;
+ default: COMMON("\n\tmovsw\n\tmovsb"); return to;
+ }
+}
+
+#undef COMMON
+}
+
+#define __HAVE_ARCH_MEMCPY
+
+#ifdef CONFIG_X86_USE_3DNOW
+
+#include <asm/mmx.h>
+
+/*
+ * This CPU favours 3DNow strongly (eg AMD Athlon)
+ */
+
+static inline void * __constant_memcpy3d(void * to, const void * from, size_t len)
+{
+ if (len < 512)
+ return __constant_memcpy(to, from, len);
+ return _mmx_memcpy(to, from, len);
+}
+
+static __inline__ void *__memcpy3d(void *to, const void *from, size_t len)
+{
+ if (len < 512)
+ return __memcpy(to, from, len);
+ return _mmx_memcpy(to, from, len);
+}
+
+#define memcpy(t, f, n) \
+(__builtin_constant_p(n) ? \
+ __constant_memcpy3d((t),(f),(n)) : \
+ __memcpy3d((t),(f),(n)))
+
+#else
+
+/*
+ * No 3D Now!
+ */
+
+#define memcpy(t, f, n) \
+(__builtin_constant_p(n) ? \
+ __constant_memcpy((t),(f),(n)) : \
+ __memcpy((t),(f),(n)))
+
+#endif
+
+#define __HAVE_ARCH_MEMMOVE
+void *memmove(void * dest,const void * src, size_t n);
+
+#define memcmp __builtin_memcmp
+
+#define __HAVE_ARCH_MEMCHR
+static inline void * memchr(const void * cs,int c,size_t count)
+{
+int d0;
+register void * __res;
+if (!count)
+ return NULL;
+__asm__ __volatile__(
+ "repne\n\t"
+ "scasb\n\t"
+ "je 1f\n\t"
+ "movl $1,%0\n"
+ "1:\tdecl %0"
+ :"=D" (__res), "=&c" (d0) : "a" (c),"0" (cs),"1" (count));
+return __res;
+}
+
+static inline void * __memset_generic(void * s, char c,size_t count)
+{
+int d0, d1;
+__asm__ __volatile__(
+ "rep\n\t"
+ "stosb"
+ : "=&c" (d0), "=&D" (d1)
+ :"a" (c),"1" (s),"0" (count)
+ :"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..
+ */
+static inline void * __constant_c_memset(void * s, unsigned long c, size_t count)
+{
+int d0, d1;
+__asm__ __volatile__(
+ "rep ; stosl\n\t"
+ "testb $2,%b3\n\t"
+ "je 1f\n\t"
+ "stosw\n"
+ "1:\ttestb $1,%b3\n\t"
+ "je 2f\n\t"
+ "stosb\n"
+ "2:"
+ : "=&c" (d0), "=&D" (d1)
+ :"a" (c), "q" (count), "0" (count/4), "1" ((long) s)
+ :"memory");
+return (s);
+}
+
+/* Added by Gertjan van Wingerde to make minix and sysv module work */
+#define __HAVE_ARCH_STRNLEN
+static inline size_t strnlen(const char * s, size_t count)
+{
+int d0;
+register int __res;
+__asm__ __volatile__(
+ "movl %2,%0\n\t"
+ "jmp 2f\n"
+ "1:\tcmpb $0,(%0)\n\t"
+ "je 3f\n\t"
+ "incl %0\n"
+ "2:\tdecl %1\n\t"
+ "cmpl $-1,%1\n\t"
+ "jne 1b\n"
+ "3:\tsubl %2,%0"
+ :"=a" (__res), "=&d" (d0)
+ :"c" (s),"1" (count));
+return __res;
+}
+/* end of additional stuff */
+
+#define __HAVE_ARCH_STRSTR
+
+extern char *strstr(const char *cs, const char *ct);
+
+/*
+ * This looks horribly ugly, but the compiler can optimize it totally,
+ * as we by now know that both pattern and count is constant..
+ */
+static 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__ __volatile__( \
+ "rep ; stosl" \
+ x \
+ : "=&c" (d0), "=&D" (d1) \
+ : "a" (pattern),"0" (count/4),"1" ((long) s) \
+ : "memory")
+{
+ int d0, d1;
+ switch (count % 4) {
+ case 0: COMMON(""); return s;
+ case 1: COMMON("\n\tstosb"); return s;
+ case 2: COMMON("\n\tstosw"); return s;
+ default: 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)))
+
+/*
+ * find the first occurrence of byte 'c', or 1 past the area if none
+ */
+#define __HAVE_ARCH_MEMSCAN
+static inline void * memscan(void * addr, int c, size_t size)
+{
+ if (!size)
+ return addr;
+ __asm__("repnz; scasb\n\t"
+ "jnz 1f\n\t"
+ "dec %%edi\n"
+ "1:"
+ : "=D" (addr), "=c" (size)
+ : "0" (addr), "1" (size), "a" (c));
+ return addr;
+}
+
+#endif /* __KERNEL__ */
+
+#endif