The following valid code snippet triggers an ICE on mainline when compiled with "-O":
================================= int foo() { volatile int a[1]; int i, *p = (int*)a; a[0] = 1; for (i = 0; i < 1; ++i) if (p[i]) return -1; return 0; } ================================= bug.c: In function 'foo': bug.c:1: internal compiler error: in gimple_rhs_has_side_effects, at gimple.c:2343 Please submit a full bug report, [etc.] -- Summary: [4.4 regression] ICE with volatile Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: ice-on-valid-code, monitored Severity: normal Priority: P3 Component: middle-end AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: reichelt at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38645