On Wed, Feb 08, 2012 at 10:27:42AM +0100, Richard Guenther wrote: > Isn't it cheaper to do that before we scan all the sequences? Thus, > I'd expect BLOCK_FOR_INSN to be NULL if the insn is in a sequence? > Like simply
Actually, on a third look, the emit-rtl.c changes aren't needed, apparently NEXT_INSN even in cfglayout mode is NULL for the in bb insns only if it is equal to get_last_insn (), unless in the header/footer sequences, but for those one shouldn't call remove_insn. To fix this bug the + /* The above might add a BARRIER as BB_END, but as barriers + aren't valid parts of a bb, remove_insn doesn't update + BB_END if it is a barrier. So adjust BB_END here. */ + while (BB_END (a) != first && BARRIER_P (BB_END (a))) + BB_END (a) = PREV_INSN (BB_END (a)); hunk is all that is needed (and the remaining cfgrtl.c hunks just a nice to have cleanup, could be postponed for 4.8). Without this BB_END (a) is a barrier, but deleted one, so get_last_insn () was actually moved to some insn before it and therefore when we emit_insn_after_noloc the b bb unchained sequence, it doesn't match get_last_insn () when it should. I'll bootstrap/regtest now just that single hunk, is that ok for trunk/4.6/4.5? Jakub