https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78118
--- Comment #2 from jcmvbkbc at gcc dot gnu.org --- The change that made xtensa backend go ICE looks completely unrelated, and indeed, the issue is caused by the side effect of compute_frame_size() function call hidden in the INITIAL_ELIMINATION_OFFSET macro. This call updates the value of the xtensa_current_frame_size static variable, used in "return" instruction predicate. Prior to the change the value of xtensa_current_frame_size was set to 0 after the end of epilogue generation, which enabled the "return" instruction for the CALL0 ABI, but after the change the additional INITIAL_ELIMINATION_OFFSET calls make xtensa_current_frame_size non-zero and "return" pattern unavailable. Get rid of the global xtensa_current_frame_size and xtensa_callee_save_size variables by moving them into the machine_function structure. Implement predicate for the "return" pattern as a function. Don't communicate completion of epilogue generation through zeroing of xtensa_current_frame_size, add explicit epilogue_done variable to the machine_function structure. Don't update stack frame layout after the completion of reload.
