stf Operation:
if (PR[qp]) {
if (imm_base_update_form)
check_target_register(r3);
if (tmp_isrcode = fp_reg_disabled(f2, 0, 0, 0))
disabled_fp_register_fault(tmp_isrcode, WRITE);

if (GR[r3].nat || (!spill_form && (FR[f2] == NATVAL)))
register_nat_consumption_fault(WRITE);

size = spill_form ? 16 : (integer_form ? 8 : fsz);

paddr = tlb_translate(GR[r3], size, WRITE, PSR.cpl, &mattr, &tmp_unused);
val = fp_fr_to_mem_format(FR[f2], size, integer_form);
mem_write(val, paddr, size, UM.be, mattr, UNORDERED, sthint);

alat_inval_multiple_entries(paddr, size);

if (imm_base_update_form) {
GR[r3] = GR[r3] + sign_ext(imm9, 9);
GR[r3].nat = 0;
mem_implicit_prefetch(GR[r3], sthint, WRITE);
}
}