https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63577
--- Comment #10 from Segher Boessenkool <segher at gcc dot gnu.org> --- Also note that doing GC during the pass will not reduce the compile time or the amount of garbage created at all, so won't fix the actual problem; it does of course make it more bearable on smaller machines. I'll have another look at what causes this; from what I remember last time I looked there simply *are* very many opportunities to combine some insns (most of which fail, maybe we could short-circuit some).