Merge branch 'master' into tobits-deprecation

1 files changed, 44 insertions, 0 deletions

diff --git a/src/main/scala/chisel3/util/Math.scala b/src/main/scala/chisel3/util/Math.scala
new file mode 100644
index 00000000..73665f0f
--- /dev/null
+++ b/src/main/scala/chisel3/util/Math.scala
@@ -0,0 +1,44 @@
+// See LICENSE for license details.
+
+/** Scala-land math helper functions, like logs.
+  */
+
+package chisel3.util
+
+import chisel3._
+
+/** Compute the log2 rounded up with min value of 1 */
+object log2Up {
+  def apply(in: BigInt): Int = {
+    require(in >= 0)
+    1 max (in-1).bitLength
+  }
+  def apply(in: Int): Int = apply(BigInt(in))
+}
+
+/** Compute the log2 rounded up */
+object log2Ceil {
+  def apply(in: BigInt): Int = {
+    require(in > 0)
+    (in-1).bitLength
+  }
+  def apply(in: Int): Int = apply(BigInt(in))
+}
+
+/** Compute the log2 rounded down with min value of 1 */
+object log2Down {
+  def apply(in: BigInt): Int = log2Up(in) - (if (isPow2(in)) 0 else 1)
+  def apply(in: Int): Int = apply(BigInt(in))
+}
+
+/** Compute the log2 rounded down */
+object log2Floor {
+  def apply(in: BigInt): Int = log2Ceil(in) - (if (isPow2(in)) 0 else 1)
+  def apply(in: Int): Int = apply(BigInt(in))
+}
+
+/** Check if an Integer is a power of 2 */
+object isPow2 {
+  def apply(in: BigInt): Boolean = in > 0 && ((in & (in-1)) == 0)
+  def apply(in: Int): Boolean = apply(BigInt(in))
+}