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-rw-r--r--libc/string/i386/string.c316
1 files changed, 316 insertions, 0 deletions
diff --git a/libc/string/i386/string.c b/libc/string/i386/string.c
new file mode 100644
index 000000000..bc85b46a1
--- /dev/null
+++ b/libc/string/i386/string.c
@@ -0,0 +1,316 @@
+/*
+ * 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 :-)
+ *
+ * NO Copyright (C) 1991, 1992 Linus Torvalds,
+ * consider these trivial functions to be PD.
+ *
+ * Modified for uClibc by Erik Andersen <andersen@codepoet.org>
+ * These make no attempt to use nifty things like mmx/3dnow/etc.
+ * These are not inline, and will therefore not be as fast as
+ * modifying the headers to use inlines (and cannot therefore
+ * do tricky things when dealing with const memory). But they
+ * should (I hope!) be faster than their generic equivalents....
+ *
+ * More importantly, these should provide a good example for
+ * others to follow when adding arch specific optimizations.
+ * -Erik
+ */
+
+#define _STDIO_UTILITY
+#define _GNU_SOURCE
+#include <string.h>
+
+#ifdef L_strcpy
+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;
+}
+#endif
+
+
+#ifdef L_strncpy
+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;
+}
+#endif
+
+
+#ifdef L_strcat
+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" (0xffffffff):"memory");
+ return dest;
+}
+#endif
+
+
+#ifdef L_strncat
+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" (0xffffffff), "g" (count)
+ : "memory");
+ return dest;
+}
+#endif
+
+
+#ifdef L_strcmp
+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;
+}
+#endif
+
+
+#ifdef L_strncmp
+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;
+}
+#endif
+
+
+#ifdef L_strchr
+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;
+}
+#endif
+
+
+#ifdef L_strrchr
+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;
+}
+#endif
+
+
+
+#ifdef L_strlen
+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" (0xffffffff));
+ return __res;
+}
+#endif
+
+
+#ifdef L_strnlen
+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;
+}
+#endif
+
+
+#ifdef L_memcpy
+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);
+}
+#endif
+
+
+#ifdef L_memmove
+void *memmove(void *dest, const void *src, size_t n)
+{
+ int d0, d1, d2;
+ if (dest<src)
+ __asm__ __volatile__(
+ "rep\n\t"
+ "movsb"
+ : "=&c" (d0), "=&S" (d1), "=&D" (d2)
+ :"0" (n),"1" (src),"2" (dest)
+ : "memory");
+ else
+ __asm__ __volatile__(
+ "std\n\t"
+ "rep\n\t"
+ "movsb\n\t"
+ "cld"
+ : "=&c" (d0), "=&S" (d1), "=&D" (d2)
+ :"0" (n),
+ "1" (n-1+(const char *)src),
+ "2" (n-1+(char *)dest)
+ :"memory");
+ return dest;
+}
+#endif
+
+#ifdef L_memchr
+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;
+}
+#endif
+
+#ifdef L_memset
+void *memset(void *s, int 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;
+}
+#endif
+
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