Remove <: Data from ModuleChoice

AI-assisted-by: Claude Code (Claude Sonnet 4.6)
Signed-off-by: Jack Koenig <koenig@sifive.com>

Author: jackkoenig

src/main/scala-2/chisel3/FixedIOModule.scala

@@ -22,6 +22,8 @@ sealed trait FixedIOBaseModule[A] extends BaseModule {
 
   protected implicit def dataProduct: DataProduct[A]
 
+  private[chisel3] def _lookupable: Lookupable[A] = lookupable
+
   // No @public, lookups implemented manually in companion object.
   final val io: A = {
     val a = ioGenerator

src/main/scala-2/chisel3/choice/ModuleChoiceIntf.scala

@@ -29,13 +29,13 @@ private[chisel3] trait ModuleChoiceObjIntf extends SourceInfoDoc { self: ModuleC
     *
     * @throws java.lang.IllegalArgumentException if the cases do not belong to the same option.
     */
-  def apply[T <: Data](
+  def apply[T](
     default: => FixedIOBaseModule[T]
   )(choices: => Seq[(Case, () => FixedIOBaseModule[T])]): T =
     macro InstChoiceTransform.apply[T]
 
   /** @group SourceInfoTransformMacro */
-  def do_apply[T <: Data](
+  def do_apply[T](
     default: => FixedIOBaseModule[T],
     choices: Seq[(Case, () => FixedIOBaseModule[T])]
   )(

src/main/scala-3/chisel3/FixedIOModule.scala

@@ -16,6 +16,8 @@ sealed trait FixedIOBaseModule[A](using lookupable: Lookupable[A]) extends BaseM
   /** A generator of IO */
   protected def ioGenerator: A
 
+  private[chisel3] def _lookupable: Lookupable[A] = lookupable
+
   @public final val io: A = {
     val dataElems = lookupable.in(ioGenerator)
     val names = LazyList.from(0).map(i => ('a' + i).toChar.toString)

src/main/scala-3/chisel3/choice/ModuleChoiceIntf.scala

@@ -2,7 +2,7 @@
 
 package chisel3.choice
 
-import chisel3.{Data, FixedIOBaseModule}
+import chisel3.FixedIOBaseModule
 import chisel3.experimental.SourceInfo
 
 private[chisel3] trait ModuleChoiceObjIntf { self: ModuleChoice.type =>
@@ -26,7 +26,7 @@ private[chisel3] trait ModuleChoiceObjIntf { self: ModuleChoice.type =>
     *
     * @throws java.lang.IllegalArgumentException if the cases do not belong to the same option.
     */
-  def apply[T <: Data](
+  def apply[T](
     default: => FixedIOBaseModule[T],
     choices: Seq[(Case, () => FixedIOBaseModule[T])]
   )(

src/main/scala/chisel3/choice/ModuleChoice.scala

@@ -6,24 +6,29 @@ import scala.collection.immutable.ListMap
 
 import chisel3.{Data, FixedIOBaseModule, Module, SourceInfoDoc}
 import chisel3.experimental.{BaseModule, SourceInfo}
+import chisel3.experimental.hierarchy.core.Lookupable
 import chisel3.internal.{groupByIntoSeq, Builder}
 import chisel3.internal.binding.InstanceChoiceBinding
 import chisel3.internal.Builder.pushCommand
 import chisel3.internal.firrtl.ir.DefInstanceChoice
 
 object ModuleChoice extends ModuleChoiceObjIntf {
 
-  protected def _applyImpl[T <: Data](
+  protected def _applyImpl[T](
     default: => FixedIOBaseModule[T],
     choices: Seq[(Case, () => FixedIOBaseModule[T])]
   )(
     implicit sourceInfo: SourceInfo
   ): T = {
     val instDefaultModule = Module.evaluate(default)
+    val lk: Lookupable[T] = instDefaultModule._lookupable
+
+    val defaultLeaves = lk.in(instDefaultModule.io)
 
     val choiceModules = choices.map { case (choice, module) =>
       val instModule = Module.evaluate(module())
-      if (!instModule.io.typeEquivalent(instDefaultModule.io)) {
+      val choiceLeaves = lk.in(instModule.io)
+      if (!defaultLeaves.zip(choiceLeaves).forall { case (a, b) => b.typeEquivalent(a) }) {
         Builder.error("Error: choice module IO bundles are not type equivalent")
       }
       Builder.options += choice
@@ -46,13 +51,14 @@ object ModuleChoice extends ModuleChoiceObjIntf {
     }
     val group = groupedChoices.head.name
 
-    val binding = instDefaultModule.io.cloneTypeFull
-    binding.bind(InstanceChoiceBinding(Builder.forcedUserModule, Builder.currentBlock))
+    val bindingLeaves = defaultLeaves.map(_.cloneTypeFull)
+    bindingLeaves.foreach(_.bind(InstanceChoiceBinding(Builder.forcedUserModule, Builder.currentBlock)))
+    val binding = lk.out(instDefaultModule.io, bindingLeaves.iterator)
 
     pushCommand(
       DefInstanceChoice(
         sourceInfo,
-        binding,
+        bindingLeaves.head,
         instDefaultModule,
         group,
         choiceModules.map { case (choice, instModule) =>