i am getting different branch occupancy (achieved) on rtx2070

[jdgh000]

I know book uses m2070, but that is too old, so I used slight newer rtx2070 fe.
I coded everything and observed the achived branch occupancy and got followings:
achieved occupancies: active warps / SM
kernel1 60.72% 19.48%
kernel2 86.09% 27.55%
kernel3 57.77% 19.49%
kernel4 60.65% 19.41%

For kernel2 and 4 makes no sense because it should be 100% utilization...
kernel2:

if (tid % warpsize)/2==0)

kernel4:
itid = tid >> 5

I wonder why?