https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97152
Bug ID: 97152
Summary: Wrong code generation since commit b6ff3ddecfa
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: stefansf at linux dot ibm.com
Target Milestone: ---
Since commit b6ff3ddecfa the following program prints the wrong number to
stdout:
int a = 0, j = 0;
int *b = 0;
int **c = &b, **i = 0;
unsigned d = 0;
unsigned short e = 4;
long f = 0;
char g = 0, k = 99;
static unsigned *dPTR = &d;
void l() {
for (;;) {
int m = 0;
for (g = 0; g == 0; g++) {
unsigned short *n = &e;
*c = &j;
if ((*n)++ == 0)
return;
for (d = 3; d <= 8; d++)
;
*dPTR = 0;
}
for (; a != 0;)
for (;;)
for (; f != 0;)
*i = &m;
}
}
int main() {
l();
printf("%d\n", d);
return d;
}
The inner loop always executes 1 time. The expression (*n)++ evaluates after
MAX_USHORT-4 times to zero which renders the if-condition true and the function
call to l returns. Prior that via *dPTR = 0 variable d gets set to zero. Thus
expected is 0 but 9 is printed. Any idea what went wrong?
