PG_ELPA
if (read_gc0_pagegrain() & PG_ELPA)
bool xpa = cpu_has_xpa && (read_c0_pagegrain() & PG_ELPA);
set_c0_pagegrain(PG_RIE | PG_XIE | PG_ELPA);
write_c0_pagegrain(pagegrain | PG_ELPA);
if (pagegrain & PG_ELPA)