[Bug c/49859] gcc could warn about statements between "switch" and first "case"
wkoszek at gmail dot com
gcc-bugzilla@gcc.gnu.org
Wed Jul 27 01:28:00 GMT 2011
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49859
--- Comment #3 from Wojciech Koszek <wkoszek at gmail dot com> 2011-07-27 01:28:28 UTC ---
Looks like GCC and Clang both agree on Duff's stuff:
wkoszek@wkoszek:~/p/duff$ cat duff.c
#include <stdio.h>
void
duff(to, from, count)
register short *to, *from;
register int count;
{
register int n=(count+7)/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);
}
}
int
main(int argc, char **argv)
{
short *dummy = NULL;
(void)argc;
(void)argv;
duff(dummy, dummy, 123);
return 0;
}
wkoszek@wkoszek:~/p/duff$ gcc -Wall -pedantic -Wunreachable-code -c duff.c
wkoszek@wkoszek:~/p/duff$ clang -Wall -pedantic -Wunreachable-code -c duff.c
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