... causes invalid removal of memory write. The following test-case will be
committed as gcc.c-torture/execute/prXXXXXX-1.c; it is miscompiled at -O2.
The first assignment to **ipp is removed in .flow2. This bug has been there
since at least 3.2.1.
void f (int **, int *, int *, int **, int **) __attribute__ ((__noinline__));
void
f (int **ipp, int *i1p, int *i2p, int **i3, int **i4)
{
**ipp = *i1p;
*ipp = i2p;
*i3 = *i4;
**ipp = 99;
}
extern void exit (int);
extern void abort (void);
int main (void)
{
int i = 42, i1 = 66, i2 = 1, i3 = -1, i4 = 55;
int *ip = &i;
int *i3p = &i3;
int *i4p = &i4;
f (&ip, &i1, &i2, &i3p, &i4p);
if (i != 66 || ip != &i2 || i2 != 99 || i3 != -1 || i3p != i4p || i4 != 55)
abort ();
exit (0);
}
--
Summary: Missed invalidation of known memory contents in flow2...
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P2
Component: rtl-optimization
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: hp at gcc dot gnu dot org
CC: gcc-bugs at gcc dot gnu dot org
GCC target triplet: cris-*
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20466
