[cover] Optimize case where d <= 8

2017-05-02 11:02:43 -07:00
parent 865918dd04
commit f2d9ef1dc0
3 changed files with 34 additions and 10 deletions
@@ -186,7 +186,8 @@ Typical gains range from 10% (at 64KB) to x5 better (at <1KB).
    Selects segments of size _k_ with the highest score to put in the dictionary.
    The score of a segment is computed by the sum of the frequencies of all the
    subsegments of of size _d_.
-    Generally _d_ should be in the range [6, 24].
+    Generally _d_ should be in the range [6, 8], but no more than 24.
+    When _d_ <= 8, the dictionary builder will run significantly faster.
    Good values for _k_ vary widely based on the input data,
    but a safe range is [32, 2048].<br />
    Example: `--train --cover=k=64,d=8 FILEs`.