This (slightly nonsensical) reduced test case crashes with an internal compiler error:
void foo(void) { int x; asm volatile("mov $0,%e0\n" :"=r" (x)); } $ gcc-4.5 tgcc.c -c -o tgcc.o tgcc.c: In function 'foo': tgcc.c:6:1: internal compiler error: in reverse_condition, at jump.c:477 -- Summary: Internal compiler error with inline asm Product: gcc Version: unknown Status: UNCONFIRMED Severity: trivial Priority: P3 Component: c AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: svfuerst at gmail dot com GCC build triplet: x86_64-linux GCC host triplet: x86_64-linux GCC target triplet: x86_64-linux http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43638