1 files changed, 32 insertions, 0 deletions
diff --git a/media/libnbaio/roundup.c b/media/libnbaio/roundup.c
new file mode 100644
index 0000000..1d552d1
--- /dev/null
+++ b/media/libnbaio/roundup.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <media/nbaio/roundup.h>
+
+unsigned roundup(unsigned v)
+{
+    // __builtin_clz is undefined for zero input
+    if (v == 0) {
+        v = 1;
+    }
+    int lz = __builtin_clz((int) v);
+    unsigned rounded = ((unsigned) 0x80000000) >> lz;
+    // 0x800000001 and higher are actually rounded _down_ to prevent overflow
+    if (v > rounded && lz > 0) {
+        rounded <<= 1;
+    }
+    return rounded;
+}