[Bug tree-optimization/27093] New: verify_ssa failed: definition does not dominate use

["debian-gcc at lists dot debian dot org" <gcc-bugzilla at gcc dot gnu dot org>]

[ forwarded from http://bugs.debian.org/361591 ]

falk@juist:/tmp% cat 309.c           
struct mark_entry { int num; };
void *t1(void);
int t2(int*);
void t3(int);
void g(void);

static void *f(void) {
    if (t1())
        return 0;    
    void *seen_numbers = 0;
    int bytes_left;
    if (t2(&bytes_left)) {
        if (bytes_left) {
            struct mark_entry *entry = t1();
            seen_numbers = t1();
            while (bytes_left) {
                t3(entry->num);
                entry++;
            }
        }
        t1();
    }
    return seen_numbers;
}

void g(void) {
    void *seen_numbers = f();
    if (!seen_numbers)
        t1();    
}

falk@juist:/tmp% gcc -O -c 309.c     
falk@juist:/tmp% gcc -O2 -c 309.c 
309.c: In function 'g':
309.c:26: error: definition in block 8 does not dominate use in block 11
for SSA_NAME: SMT.5_37 in statement:
SMT.5_20 = PHI <SMT.5_37(8), SMT.5_31(2), SMT.5_35(3), SMT.5_37(11)>;
PHI argument
SMT.5_37
for PHI node
SMT.5_20 = PHI <SMT.5_37(8), SMT.5_31(2), SMT.5_35(3), SMT.5_37(11)>;
309.c:26: internal compiler error: verify_ssa failed
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

I don't have 4.1 or earlier with checking enabled, so I cannot check 
whether the problem is present there.

    Falk


-- 
           Summary: verify_ssa failed: definition does not dominate use
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: debian-gcc at lists dot debian dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27093