Since r141534 (PR37542), the following testcase segfaults during fre at -O1 and higher:
template <typename To, typename From> static inline To bitwise_cast (From from) { union { From f; To t; } u; u.f = from; return u.t; } extern void foo (unsigned char *); double bar () { unsigned char b[sizeof (unsigned long long)]; foo (b); return bitwise_cast<double> (*(unsigned long long *) b); } -- Summary: [4.4/4.5 Regression] ICE in get_expr_value_id Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: ice-on-valid-code Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: jakub at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39713