safescatter.fut

let safescatter 't [m] [n] (dest: *[m]t) (is: [n]i32) (vs: [n]t): *[m]t =
  let dest' = scatter dest is vs
  let in_bounds = scatter (replicate 1 true)
                          (map (\i -> if i >= 0 && i < m then -1 else 0) is)
                          (replicate n false)
  in assert in_bounds[0] dest'

-- ==
-- entry: test_scatter test_safescatter
-- random input { 100 [1000000]i32 } auto output
-- random input { 1000 [1000000]i32 } auto output
-- random input { 10000 [1000000]i32 } auto output
-- random input { 1000 [1000000]i32 } auto output
-- random input { 10000 [1000000]i32 } auto output
-- random input { 100000 [1000000]i32 } auto output

entry test_scatter (m: i32) (is: []i32) =
  scatter (replicate m 0) (map (%m) is) (map (%m) is)

entry test_safescatter (m: i32) (is: []i32) =
  safescatter (replicate m 0) (map (%m) is) (map (%m) is)