Added retime annotation

tapeout/src/main/scala/transforms/retime/Retime.scala

@@ -0,0 +1,45 @@
+// See LICENSE for license details.
+
+package barstools.tapeout.transforms.retime
+
+import chisel3.internal.InstanceId
+import firrtl.PrimOps.Not
+import firrtl.annotations.{Annotation, CircuitName, ModuleName, Named, ComponentName}
+import firrtl.ir.{Input, UIntType, IntWidth, Module, Port, DefNode, NoInfo, Reference, DoPrim, Block, Circuit}
+import firrtl.passes.Pass
+import firrtl.{CircuitForm, CircuitState, LowForm, Transform}
+
+object RetimeAnnotation {
+  def apply(target: ModuleName): Annotation = Annotation(target, classOf[RetimeTransform], "retime")
+  def unapply(a: Annotation): Option[Named] = a match {
+    case Annotation(m, t, "retime") if t == classOf[RetimeTransform] => Some(m)
+    case _ => None
+  }
+}
+
+class RetimeTransform extends Transform {
+  override def inputForm: CircuitForm = LowForm
+  override def outputForm: CircuitForm = LowForm
+
+  override def execute(state: CircuitState): CircuitState = {
+    getMyAnnotations(state) match {
+      case Nil => state
+      case seq => seq.foreach {
+        case RetimeAnnotation(ModuleName(module, CircuitName(_))) =>
+          logger.info(s"Retiming module $module")
+        case RetimeAnnotation(ComponentName(name, ModuleName(module, CircuitName(_)))) =>
+          logger.info(s"Retiming instance $module.$name")
+        case _ =>
+          throw new Exception(s"There should be RetimeAnnotations, got ${seq.mkString(" -- ")}")
+      }
+      state
+    }
+  }
+}
+
+trait RetimeLib {
+  self: chisel3.Module =>
+  def retime(component: InstanceId): Unit = {
+    annotate(chisel3.experimental.ChiselAnnotation(component, classOf[RetimeTransform], "retime"))
+  }
+}