Introduce fls() helper

This is needed for virtio.  The implementation is originally from 
Marcelo Tosatti.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5868 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 11 insertions, 0 deletions

diff --git a/cutils.c b/cutils.c
index 142347d6a..9f124f5ea 100644
--- a/cutils.c
+++ b/cutils.c
@@ -95,3 +95,14 @@ time_t mktimegm(struct tm *tm)
     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
     return t;
 }
+
+int fls(int i)
+{
+    int bit;
+
+    for (bit=31; bit >= 0; bit--)
+        if (i & (1 << bit))
+            return bit+1;
+
+    return 0;
+}