NR_STACK_ARG_REGS
if (idx < NR_STACK_ARG_REGS)
emit(A64_LDR64I(dst, A64_FP, (idx - NR_STACK_ARG_REGS) * sizeof(u64) + 16), ctx);
if (idx < NR_STACK_ARG_REGS)
emit(A64_STR64I(src_a64, A64_SP, (idx - NR_STACK_ARG_REGS) * sizeof(u64)), ctx);
if (idx < NR_STACK_ARG_REGS) {
emit(A64_STR64I(tmp, A64_SP, (idx - NR_STACK_ARG_REGS) * sizeof(u64)), ctx);
int nr_on_stack = out_cnt - NR_STACK_ARG_REGS;