use a compiler builtin (which uses processor instructions) for this operation

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@33933 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_agent.c

@@ -1334,12 +1334,13 @@ static struct ast_channel *agent_request(const char *type, int format, void *dat
 	return chan;
 }
 
-static int powerof(unsigned int v)
+static force_inline int powerof(unsigned int d)
 {
-	int x;
-	for (x=0;x<32;x++) {
-		if (v & (1 << x)) return x;
-	}
+	int x = ffs(d);
+
+	if (x)
+		return x - 1;
+
 	return 0;
 }
 

translate.c

@@ -74,13 +74,15 @@ static struct translator_path tr_matrix[MAX_FORMAT][MAX_FORMAT];
  */
 
 /*! \brief returns the index of the lowest bit set */
-static int powerof(int d)
+static force_inline int powerof(unsigned int d)
 {
-	int x;
-	for (x = 0; x < MAX_FORMAT; x++)
-		if ((1 << x) & d)
-			return x;
-	ast_log(LOG_WARNING, "Powerof %d: No power??\n", d);
+	int x = ffs(d);
+
+	if (x)
+		return x - 1;
+
+	ast_log(LOG_WARNING, "No bits set? %d\n", d);
+
 	return -1;
 }