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/* NOCW */
/* dggccbug.c */
/* bug found by Eric Young (eay@cryptsoft.com) - 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
}
}
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