You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
110 lines
2.2 KiB
110 lines
2.2 KiB
9 years ago
|
#include <stdio.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include "dbg.h"
|
||
|
|
|
||
|
|
int normal_copy(char *from, char *to, int count)
|
||
|
|
{
|
||
|
|
int i = 0;
|
||
|
|
|
||
|
|
for(i = 0; i < count; i++) {
|
||
|
|
to[i] = from[i];
|
||
|
|
}
|
||
|
|
|
||
|
|
return i;
|
||
|
|
}
|
||
|
|
|
||
|
|
int duffs_device(char *from, char *to, int count)
|
||
|
|
{
|
||
|
|
{
|
||
|
|
int n = (count + 7) / 8;
|
||
|
|
debug("n=%d, (count %% 8)=%d", n, count % 8);
|
||
|
|
|
||
|
|
switch(count % 8) {
|
||
|
|
case 0: do { *to++ = *from++;
|
||
|
|
case 7: *to++ = *from++;
|
||
|
|
case 6: *to++ = *from++;
|
||
|
|
case 5: *to++ = *from++;
|
||
|
|
case 4: *to++ = *from++;
|
||
|
|
case 3: *to++ = *from++;
|
||
|
|
case 2: *to++ = *from++;
|
||
|
|
case 1: *to++ = *from++;
|
||
|
|
} while(--n > 0);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return count;
|
||
|
|
}
|
||
|
|
|
||
|
|
int zeds_device(char *from, char *to, int count)
|
||
|
|
{
|
||
|
|
{
|
||
|
|
int n = (count + 7) / 8;
|
||
|
|
|
||
|
|
switch(count % 8) {
|
||
|
|
case 0:
|
||
|
|
again: *to++ = *from++;
|
||
|
|
case 7: *to++ = *from++;
|
||
|
|
case 6: *to++ = *from++;
|
||
|
|
case 5: *to++ = *from++;
|
||
|
|
case 4: *to++ = *from++;
|
||
|
|
case 3: *to++ = *from++;
|
||
|
|
case 2: *to++ = *from++;
|
||
|
|
case 1: *to++ = *from++;
|
||
|
|
if(--n > 0) goto again;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return count;
|
||
|
|
}
|
||
|
|
|
||
|
|
int valid_copy(char *data, int count, char expects)
|
||
|
|
{
|
||
|
|
int i = 0;
|
||
|
|
for(i = 0; i < count; i++) {
|
||
|
|
if(data[i] != expects) {
|
||
|
|
log_err("[%d] %c != %c", i, data[i], expects);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
int main(int argc, char *argv[])
|
||
|
|
{
|
||
|
|
char from[1000] = {'a'};
|
||
|
|
char to[1000] = {'c'};
|
||
|
|
int rc = 0;
|
||
|
|
|
||
|
|
// setup the from to have some stuff
|
||
|
|
memset(from, 'x', 1000);
|
||
|
|
// set it to a failure mode
|
||
|
|
memset(to, 'y', 1000);
|
||
|
|
check(valid_copy(to, 1000, 'y'), "Not initialized right.");
|
||
|
|
|
||
|
|
// use normal copy to
|
||
|
|
rc = normal_copy(from, to, 1000);
|
||
|
|
check(rc == 1000, "Normal copy failed: %d", rc);
|
||
|
|
check(valid_copy(to, 1000, 'x'), "Normal copy failed.");
|
||
|
|
|
||
|
|
// reset
|
||
|
|
memset(to, 'y', 1000);
|
||
|
|
|
||
|
|
// duffs version
|
||
|
|
rc = duffs_device(from, to, 1000);
|
||
|
|
check(rc == 1000, "Duff's deice failed: %d", rc);
|
||
|
|
check(valid_copy(to, 1000, 'x'), "Duff's deice failed copy.");
|
||
|
|
|
||
|
|
// reset
|
||
|
|
memset(to, 'y', 1000);
|
||
|
|
|
||
|
|
// my version
|
||
|
|
rc = zeds_device(from, to, 1000);
|
||
|
|
check(rc == 1000, "Zed's device failed: %d", rc);
|
||
|
|
check(valid_copy(to, 1000, 'x'), "Zed's device failed copy.");
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
error:
|
||
|
|
return 1;
|
||
|
|
}
|