On 2/19/2014, 6:54 AM, Joey Ye wrote:
Vlad,When fixing PR60169, I found that reload fail to assert verify_initial_elim_offsets () if (insns_need_reload != 0 || something_needs_elimination || something_needs_operands_changed) { HOST_WIDE_INT old_frame_size = get_frame_size (); reload_as_needed (global); gcc_assert (old_frame_size == get_frame_size ()); gcc_assert (verify_initial_elim_offsets ()); } The reason is that stack layout changes during reload_as_needed as a result of a thumb1 backend heuristic. I have a patch to make sure the heuristic doesn't change stack layout during and after reload, and the assertion disappeared. However, I'm not sure if it will also be a problem in lra. Here is the question more specific: Is that any chance during lra_in_progress that: stack layout can no longer be altered, but insns can still be added or changed?
I believe LRA is less prone to the above reload problem because of its design. You can change stack in the backend and all will work if you provide the right sfp to hfp/sp offsets. In fact, LRA itself can allocate stack slots several times and add and change insns between these allocations.
