Reimplementation of prefix sets.

Prefix sets were broken beyond any repair and have to be reimplemented.
They are reimplemented using a trie with bitmasks in nodes.
There is also change in the interpretation of minus prefix pattern,
but the old interpretation was already inconsistent with
the documentation and broken.

There is also some bugfixes in filter code related to set variables.

1 files changed, 21 insertions, 0 deletions

diff --git a/lib/bitops.c b/lib/bitops.c
index 6ca0505..88cef78 100644
--- a/lib/bitops.c
+++ b/lib/bitops.c
@@ -45,3 +45,24 @@ u32_masklen(u32 x)
   if (x & 0xaaaaaaaa) l++;
   return l;
 }
+
+/**
+ * u32_log2 - compute a binary logarithm.
+ * @v: number
+ *
+ * This function computes a integral part of binary logarithm of given
+ * integer @v and returns it. The computed value is also an index of the
+ * first non-zero bit position.
+ */
+
+u32
+u32_log2(u32 v)
+{
+  u32 r, shift;
+  r =     (v > 0xFFFF) << 4; v >>= r;
+  shift = (v > 0xFF  ) << 3; v >>= shift; r |= shift;
+  shift = (v > 0xF   ) << 2; v >>= shift; r |= shift;
+  shift = (v > 0x3   ) << 1; v >>= shift; r |= shift;
+  r |= (v >> 1);
+  return r;
+}