ref: 4040ea7a5eda976098131794e8df3b162cafa8f4
dir: /sys/src/ape/lib/openssl/bugs/dggccbug.c/
/* NOCW */
/* dggccbug.c */
/* bug found by Eric Young ([email protected]) - May 1995 */
#include <stdio.h>
/* There is a bug in
* gcc version 2.5.8 (88open OCS/BCS, DG-2.5.8.3, Oct 14 1994)
* as shipped with DGUX 5.4R3.10 that can be bypassed by defining
* DG_GCC_BUG in my code.
* The bug manifests itself by the vaule of a pointer that is
* used only by reference, not having it's value change when it is used
* to check for exiting the loop. Probably caused by there being 2
* copies of the valiable, one in a register and one being an address
* that is passed. */
/* compare the out put from
* gcc dggccbug.c; ./a.out
* and
* gcc -O dggccbug.c; ./a.out
* compile with -DFIXBUG to remove the bug when optimising.
*/
void inc(a)
int *a;
{
(*a)++;
}
main()
{
int p=0;
#ifdef FIXBUG
int dummy;
#endif
while (p<3)
{
fprintf(stderr,"%08X\n",p);
inc(&p);
#ifdef FIXBUG
dummy+=p;
#endif
}
}