http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57381
Bug ID: 57381 Summary: array of volatile pointers hangs gcc Product: gcc Version: 4.9.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: dhazeghi at yahoo dot com The following code causes gcc trunk and 4.8 branch to hang at -O1 or above due to it consuming all available memory (well over 2GB after 10 seconds). $ gcc-trunk -v Target: x86_64-unknown-linux-gnu gcc version 4.9.0 20130522 (experimental) [trunk revision 199191] (GCC) $ time gcc-trunk -O0 -c small.c real 0m0.023s user 0m0.008s sys 0m0.008s $ time gcc-4.7 -O1 -c small.c real 0m0.028s user 0m0.004s sys 0m0.016s $ time timeout 10 gcc-trunk -O1 -c small.c real 0m10.002s user 0m0.000s sys 0m0.004s $ echo $? 124 ---------------------------------- struct S0 { int f0, f1, f2; }; struct S1 { int f0; volatile struct S0 f2; }; static struct S1 s = {0x47BED265,{0x06D4EB3E,5,0U}}; int foo(struct S0 p) { for (s.f2.f2 = 0; (s.f2.f2 <= 12); s.f2.f2++) { volatile int *l_61[5][2][2] = {{{&s.f2.f0,&s.f2.f0},{&s.f2.f0,&s.f2.f0}},{{&s.f2.f0,&s.f2.f0},{&s.f2.f0,&s.f2.f0}},{{&s.f2.f0,(void*)0},{&s.f2.f0,&s.f2.f0}},{{&s.f2.f0,&s.f2.f0},{&s.f2.f0,&s.f2.f0}},{{&s.f2.f0,&s.f2.f0},{(void*)0,&s.f2.f0}}}; volatile int **l_68 = &l_61[0][0][1]; volatile int *l_76 = &s.f2.f0; (*l_68) = l_61[0][0][0]; if ((*l_76 = (p.f2 % 5))) ; } return p.f0; }