Implement memset memcpy, calloc

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1055 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2001-10-30 22:37:01 +00:00
parent db351718d0
commit 53b20c34dc

View File

@ -10,6 +10,7 @@
//
//===----------------------------------------------------------------------===//
#include <stdlib.h>
// Prototypes for functions exported by LLI directly.
void exit(int Code);
@ -140,8 +141,92 @@ long int atol(const char *nptr) {
}
//===----------------------------------------------------------------------===//
// memory stuff...
//===----------------------------------------------------------------------===//
// 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;
}
void *calloc(size_t nelem, size_t elsize) {
void *Result = malloc(nelem*elsize);
return memset(Result, 0, nelem*elsize);
}
//===----------------------------------------------------------------------===//