type of vm.stats.vm.v_vnodepgsin vm.stats.vm.v_swappgsin, vm.stats.vm.v_vnodepgsout vm.stats.vm.v_swappgsout on AMD64 r320730

Dears

I'm the maintainer of xosview and I'm debugging rather weird behavior 
from it in the latest FreeBSD 12 revisions (12.0-CURRENT #0 r320730 
AMD64) . The problem is occurring on the lines responsible for 
collecting statistics about paging. These lines follow:

If (pageinfo) {
Pageinfo [0] = (uint64_t) vm.v_vnodepgsin + (uint64_t) vm.v_swappgsin;
Pageinfo [1] = (uint64_t) vm.v_vnodepgsout + (uint64_t) vm.v_swappgsout;
}

This code works on FreeBSD 11 and until a short time ago it works at 12. 
But now it returns extremely large values ​​when interpreted as 64-bit 
values. A debugging has shown that for this sysctl call the following 
values ​​are returned in the terminal:
sysctl vm.stats.vm.v_vnodepgsin vm.stats.vm.v_swappgsin 
vm.stats.vm.v_vnodepgsout vm.stats.vm.v_swappgsout
Vm.stats.vm.v_vnodepgsin: 47432
Vm.stats.vm.v_swappgsin: 0
Vm.stats.vm.v_vnodepgsout: 19
Vm.stats.vm.v_swappgsout: 0

While the code returns things like:

Pageinf [0] = 34359785800; Pageinfo [1] = 140733193388051
Pageinf [0] = 34359785800; Pageinfo [1] = 2678138638516092947

After some tests I found that if I change the code to use a typecast to 
(uint32_t) then Xosview works correctly.:
If (pageinfo) {
Pageinfo [0] = (uint32_t) ((uint64_t) vm.v_vnodepgsin + (uint64_t) 
vm.v_swappgsin);
Pageinfo [1] = (uint32_t) ((uint64_t) vm.v_vnodepgsout + (uint64_t) 
vm.v_swappgsout);
}

For me, it seems that some code in the kernel is storing values ​​as 32 
bits where it should be 64 bits. Is this behavior correct?

[]'s

-Otacílio