add atime test

Author: ben-schwen

.ci/atime/tests.R

@@ -424,5 +424,16 @@ test.list <- atime::atime_test_list(
     seconds.limit = 1,
     expr = data.table:::`[.data.table`(dt, , base::max(V1, na.rm = TRUE), by = id)),
 
+  # speed up bmerge for double columns
+  "bmerge numeric roll improved in this PR" = atime::atime_test(
+    setup = {
+      x = data.table(id = as.double(seq_len(N)))
+      i = data.table(id = as.double(seq_len(N)) + 0.5)
+      setkey(x, id)
+    },
+    Slow = "4ebcd64c3976973d0d601dcbee4daf39a986e091",
+    Fast = "8e8cbbed5e77f657b39dd28b5a87c563fae0c58e",
+    expr = data.table:::`[.data.table`(x, i, roll = TRUE, which = TRUE)),
+
   tests=extra.test.list)
 # nolint end: undesirable_operator_linter.