Improve performance of LowerTypes renaming (#2024)

This is done by having LowerTypes uses two RenameMaps instead of one for
each module. There is one for renaming instance paths, and one for
renaming everything within modules.

Also add some utilities:
* TargetUtils for dealing with InstanceTargets
* RenameMap.fromInstanceRenames

1 files changed, 39 insertions, 0 deletions

diff --git a/src/test/scala/firrtl/RenameMapPrivateSpec.scala b/src/test/scala/firrtl/RenameMapPrivateSpec.scala
new file mode 100644
index 00000000..d735e6c8
--- /dev/null
+++ b/src/test/scala/firrtl/RenameMapPrivateSpec.scala
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package firrtl
+
+import firrtl.annotations.Target
+import firrtl.annotations.TargetToken.{Instance, OfModule}
+import firrtl.analyses.InstanceKeyGraph
+import firrtl.testutils.FirrtlFlatSpec
+
+class RenameMapPrivateSpec extends FirrtlFlatSpec {
+  "RenameMap.fromInstanceRenames" should "handle instance renames" in {
+    def tar(str: String): Target = Target.deserialize(str)
+    val circuit = parse(
+      """circuit Top :
+        |  module Bar :
+        |    skip
+        |  module Foo :
+        |    inst bar of Bar
+        |  module Top :
+        |    inst foo1 of Foo
+        |    inst foo2 of Foo
+        |    inst bar of Bar
+        |""".stripMargin
+    )
+    val graph = InstanceKeyGraph(circuit)
+    val renames = Map(
+      OfModule("Foo") -> Map(Instance("bar") -> Instance("bbb")),
+      OfModule("Top") -> Map(Instance("foo1") -> Instance("ffff"))
+    )
+    val rm = RenameMap.fromInstanceRenames(graph, renames)
+    rm.get(tar("~Top|Top/foo1:Foo")) should be(Some(Seq(tar("~Top|Top/ffff:Foo"))))
+    rm.get(tar("~Top|Top/foo2:Foo")) should be(None)
+    // Check of nesting
+    rm.get(tar("~Top|Top/foo1:Foo/bar:Bar")) should be(Some(Seq(tar("~Top|Top/ffff:Foo/bbb:Bar"))))
+    rm.get(tar("~Top|Top/foo2:Foo/bar:Bar")) should be(Some(Seq(tar("~Top|Top/foo2:Foo/bbb:Bar"))))
+    rm.get(tar("~Top|Foo/bar:Bar")) should be(Some(Seq(tar("~Top|Foo/bbb:Bar"))))
+    rm.get(tar("~Top|Top/bar:Bar")) should be(None)
+  }
+}