From abeff01f0714d5474b9d18d78fc13011e5ad6b99 Mon Sep 17 00:00:00 2001
From: Jiuyang Liu
Date: Sat, 27 Mar 2021 00:53:25 +0000
Subject: Add NoConstantPropagationAnnotation to disable constatnt propagation
 (#2150)

* add --no-constant-propagation to disable constant propagation

* add test

* deprecate DisableFold.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>---
 src/test/scala/firrtlTests/ConstantPropagationTests.scala | 11 +++++++++++
 1 file changed, 11 insertions(+)

(limited to 'src/test')

diff --git a/src/test/scala/firrtlTests/ConstantPropagationTests.scala b/src/test/scala/firrtlTests/ConstantPropagationTests.scala
index 60cf1b8b..bc7f92e6 100644
--- a/src/test/scala/firrtlTests/ConstantPropagationTests.scala
+++ b/src/test/scala/firrtlTests/ConstantPropagationTests.scala
@@ -908,6 +908,17 @@ class ConstantPropagationIntegrationSpec extends LowTransformSpec {
     execute(input, check, Seq(dontTouch("Child.in1")))
   }
 
+  it should "NOT optimize if no-constant-propagation is enabled" in {
+    val input =
+      """circuit Foo:
+        |  module Foo:
+        |    input a: UInt<1>
+        |    output b: UInt<1>
+        |    b <= and(UInt<1>(0), a)""".stripMargin
+    val check = parse(input).serialize
+    execute(input, check, Seq(NoConstantPropagationAnnotation))
+  }
+
   it should "still propagate constants even when there is name swapping" in {
     val input =
       """circuit Top :
-- 
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