https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104310 --- Comment #2 from David Binderman <dcb314 at hotmail dot com> --- The code I gave crashes in fre. This code crashes in forwprop: int i_5; void func_3() { int *ptr_11; unsigned int ui_15; ptr_11 = &ui_15; (ui_15 = 0 >= 0) / i_5 << 1; } My apologies for getting the reduction wrong.