llvm-6502/runtime/GCCLibraries/libc/string.c
Chris Lattner 4ee8dd7f2b Add strcat function
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1847 91177308-0d34-0410-b5e6-96231b3b80d8
2002-03-11 17:46:50 +00:00

133 lines
3.1 KiB
C

//===-- string.c - String functions for the LLVM libc Library -----*- C -*-===//
//
// A lot of this code is ripped gratuitously from glibc and libiberty.
//
//===----------------------------------------------------------------------===//
#include <stdlib.h>
void *malloc(unsigned);
void free(void *);
unsigned strlen(const char *Str) {
int Count = 0;
while (*Str) { ++Count; ++Str; }
return Count;
}
char *strdup(const char *str) {
int Len = strlen(str);
char *Result = (char*)malloc((Len+1)*sizeof(char));
memcpy(Result, str, Len+1);
return Result;
}
char *strcpy(char *s1, const char *s2) {
while ((*s1++ = *s2++));
return s1;
}
char *strcat(char *s1, const char *s2) {
strcpy(s1+strlen(s1), s2);
return s1;
}
/* Compare S1 and S2, returning less than, equal to or
greater than zero if S1 is lexicographically less than,
equal to or greater than S2. */
int strcmp (const char *p1, const char *p2) {
register const unsigned char *s1 = (const unsigned char *) p1;
register const unsigned char *s2 = (const unsigned char *) p2;
unsigned char c1, c2;
do
{
c1 = (unsigned char) *s1++;
c2 = (unsigned char) *s2++;
if (c1 == '\0')
return c1 - c2;
}
while (c1 == c2);
return c1 - c2;
}
// http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc/sysdeps/generic/?cvsroot=glibc
typedef unsigned int op_t;
#define OPSIZ 4
void *memset (void *dstpp, int c, size_t len) {
long long int dstp = (long long int) dstpp;
if (len >= 8)
{
size_t xlen;
op_t cccc;
cccc = (unsigned char) c;
cccc |= cccc << 8;
cccc |= cccc << 16;
if (OPSIZ > 4)
/* Do the shift in two steps to avoid warning if long has 32 bits. */
cccc |= (cccc << 16) << 16;
/* There are at least some bytes to set.
No need to test for LEN == 0 in this alignment loop. */
while (dstp % OPSIZ != 0)
{
((unsigned char *) dstp)[0] = c;
dstp += 1;
len -= 1;
}
/* Write 8 `op_t' per iteration until less than 8 `op_t' remain. */
xlen = len / (OPSIZ * 8);
while (xlen > 0)
{
((op_t *) dstp)[0] = cccc;
((op_t *) dstp)[1] = cccc;
((op_t *) dstp)[2] = cccc;
((op_t *) dstp)[3] = cccc;
((op_t *) dstp)[4] = cccc;
((op_t *) dstp)[5] = cccc;
((op_t *) dstp)[6] = cccc;
((op_t *) dstp)[7] = cccc;
dstp += 8 * OPSIZ;
xlen -= 1;
}
len %= OPSIZ * 8;
/* Write 1 `op_t' per iteration until less than OPSIZ bytes remain. */
xlen = len / OPSIZ;
while (xlen > 0)
{
((op_t *) dstp)[0] = cccc;
dstp += OPSIZ;
xlen -= 1;
}
len %= OPSIZ;
}
/* Write the last few bytes. */
while (len > 0)
{
((unsigned char *) dstp)[0] = c;
dstp += 1;
len -= 1;
}
return dstpp;
}
void *memcpy(void *dstpp, const void *srcpp, size_t len) {
char *dstp = (char*)dstpp;
char *srcp = (char*) srcpp;
unsigned i;
for (i = 0; i < len; ++i)
dstp[i] = srcp[i];
return dstpp;
}