The following valid code snippet triggers an ICE since GCC 4.0.0 (only with the C frontend):
======================================== struct A { int i; }; void foo() { ((struct A) { 0 }).i += 1; } ======================================== bug.c: In function 'foo': bug.c:5: internal compiler error: in gimple_add_tmp_var, at gimplify.c:720 Please submit a full bug report, [etc.] -- Summary: [4.0/4.1/4.2 regression] ICE incrementing temporary variable Product: gcc Version: 4.2.0 Status: UNCONFIRMED Keywords: ice-on-valid-code, monitored Severity: normal Priority: P3 Component: c 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=28418