deque block_size<8>, 64 elems: first segment holds 8 elements, 9 segments spanned

--- reported case: 64 source elements, every element copied ---
copy_if flat dst             block=-     n=64      every=1   pred_applied=64       mandated=64       extra=0      (0.000%)
copy_if deque dst            block=8     n=64      every=1   pred_applied=71       mandated=64       extra=7      (10.938%)
copy_if deque dst (nsg)      block=8     n=64      every=1   pred_applied=64       mandated=64       extra=0      (0.000%)

--- 2S: flat vector source, deque destination, every=1 (all pass) ---
  flat dst  (control)        block=-     n=100000  every=1   pred_applied=100000   mandated=100000   extra=0      (0.000%)
  deque dst                  block=8     n=100000  every=1   pred_applied=112499   mandated=100000   extra=12499  (12.499%)
  deque dst                  block=16    n=100000  every=1   pred_applied=106249   mandated=100000   extra=6249   (6.249%)
  deque dst                  block=32    n=100000  every=1   pred_applied=103124   mandated=100000   extra=3124   (3.124%)
  deque dst                  block=64    n=100000  every=1   pred_applied=101562   mandated=100000   extra=1562   (1.562%)
  deque dst                  block=128   n=100000  every=1   pred_applied=100781   mandated=100000   extra=781    (0.781%)
  deque dst                  block=256   n=100000  every=1   pred_applied=100390   mandated=100000   extra=390    (0.390%)
  deque dst                  block=512   n=100000  every=1   pred_applied=100195   mandated=100000   extra=195    (0.195%)

--- 2S: flat vector source, deque destination, every=2 (half pass) ---
  flat dst  (control)        block=-     n=100000  every=2   pred_applied=100000   mandated=100000   extra=0      (0.000%)
  deque dst                  block=8     n=100000  every=2   pred_applied=106249   mandated=100000   extra=6249   (6.249%)
  deque dst                  block=16    n=100000  every=2   pred_applied=103124   mandated=100000   extra=3124   (3.124%)
  deque dst                  block=32    n=100000  every=2   pred_applied=101562   mandated=100000   extra=1562   (1.562%)
  deque dst                  block=64    n=100000  every=2   pred_applied=100781   mandated=100000   extra=781    (0.781%)
  deque dst                  block=128   n=100000  every=2   pred_applied=100390   mandated=100000   extra=390    (0.390%)
  deque dst                  block=256   n=100000  every=2   pred_applied=100195   mandated=100000   extra=195    (0.195%)
  deque dst                  block=512   n=100000  every=2   pred_applied=100097   mandated=100000   extra=97     (0.097%)

--- 2S miss: flat vector source, deque destination, every=0 (none pass) ---
  flat dst  (control)        block=-     n=100000  every=0   pred_applied=100000   mandated=100000   extra=0      (0.000%)
  deque dst                  block=8     n=100000  every=0   pred_applied=100000   mandated=100000   extra=0      (0.000%)
  deque dst                  block=128   n=100000  every=0   pred_applied=100000   mandated=100000   extra=0      (0.000%)

--- 1+2S: deque source (block 128), deque destination ---
  flat dst  (1S control)     block=-     n=100000  every=1   pred_applied=100000   mandated=100000   extra=0      (0.000%)
  deque dst                  block=128   n=100000  every=1   pred_applied=100000   mandated=100000   extra=0      (0.000%)
  deque dst                  block=128   n=100000  every=2   pred_applied=100000   mandated=100000   extra=0      (0.000%)

--- recursively segmented destinations, flat source, n=4096 ---
  flat dst  (control)        block=-     n=4096    every=1   pred_applied=4096     mandated=4096     extra=0      (0.000%)
  seg_vector dst  (d1)       block=64    n=4096    every=1   pred_applied=4159     mandated=4096     extra=63     (1.538%)
  seg2_vector dst (d2)       block=64    n=4096    every=1   pred_applied=4174     mandated=4096     extra=78     (1.904%)
  seg_vector dst  (d1)       block=64    n=4096    every=2   pred_applied=4127     mandated=4096     extra=31     (0.757%)
  seg2_vector dst (d2)       block=64    n=4096    every=2   pred_applied=4134     mandated=4096     extra=38     (0.928%)

