On Fri, 2 Mar 2018, Peter Bergner wrote:
> But currently ira-lives.c:process_bb_node_lives() has:
>
> /* Don't allocate allocnos that cross setjmps or any
> call, if this function receives a nonlocal
> goto. */
> if (cfun->has_nonlocal_label
> || find_reg_note (insn, REG_SETJMP,
> NULL_RTX) != NULL_RTX)
> {
> SET_HARD_REG_SET (OBJECT_CONFLICT_HARD_REGS (obj));
> SET_HARD_REG_SET (OBJECT_TOTAL_CONFLICT_HARD_REGS (obj));
> }
>
> ...which forces us to spill everything live across the setjmp by forcing
> the pseudos to interfere all hardregs. That can't be good for performance.
> What am I missing?
FWIW there's a similar issue with exceptions where IRA chooses memory
for pseudos inside the loop even though the throwing call is outside:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82242#c3
Alexander
