add decoder test

3 files changed, 44 insertions, 3 deletions

diff --git a/src/test/scala/chiselTests/ChiselSpec.scala b/src/test/scala/chiselTests/ChiselSpec.scala
index e9ec2dae..1f1b5399 100644
--- a/src/test/scala/chiselTests/ChiselSpec.scala
+++ b/src/test/scala/chiselTests/ChiselSpec.scala
@@ -40,10 +40,10 @@ class ChiselPropSpec extends PropSpec with PropertyChecks {
 
   def popCount(n: Long) = n.toBinaryString.count(_=='1')
 
-  val smallPosInts = Gen.choose(1, 16)
+  val smallPosInts = Gen.choose(1, 8)
   val safeUIntWidth = Gen.choose(1, 31) 
   val safeUInts = Gen.choose(0, (1 << 30))
   val vecSizes = Gen.choose(0, 4)
   def enSequence(n: Int) = Gen.containerOfN[List,Boolean](n,Gen.oneOf(true,false))
+  val binaryString = for(i <- Arbitrary.arbitrary[Int]) yield "b" + i.toBinaryString
 }
-
diff --git a/src/test/scala/chiselTests/ComplexAssign.scala b/src/test/scala/chiselTests/ComplexAssign.scala
index ab940440..47041ddd 100644
--- a/src/test/scala/chiselTests/ComplexAssign.scala
+++ b/src/test/scala/chiselTests/ComplexAssign.scala
@@ -42,7 +42,7 @@ class ComplexAssignSpec extends ChiselPropSpec {
   }
      
   property("All complex assignments should return the correct result") {
-    forAll(enSequence(16), safeUInts, safeUInts) { (en: List[Boolean], re: Int, im: Int) =>
+    forAll(enSequence(4), safeUInts, safeUInts) { (en: List[Boolean], re: Int, im: Int) =>
       assert(execute{ new ComplexAssignTester(en, re, im) }) 
     }
   }
diff --git a/src/test/scala/chiselTests/Decoder.scala b/src/test/scala/chiselTests/Decoder.scala
new file mode 100644
index 00000000..cc463600
--- /dev/null
+++ b/src/test/scala/chiselTests/Decoder.scala
@@ -0,0 +1,41 @@
+package chiselTests
+import Chisel._
+import org.scalatest._
+import org.scalatest.prop._
+import org.scalacheck._
+import Chisel.testers.BasicTester
+
+class Decoder(bitpats: List[String]) extends Module {
+  val io = new Bundle {
+    val inst  = UInt(INPUT, 32)
+    val match_idx = UInt(OUTPUT, 5)
+  }
+  io.match_idx := Vec(bitpats.map(BitPat(_) === io.inst)).indexWhere{i: Bool => i}
+}
+
+class DecoderSpec extends ChiselPropSpec {
+
+  class DecoderTester(pairs: List[(String, String)]) extends BasicTester {
+    val (insts, bitpats) = pairs.unzip
+    val (cnt, wrap) = Counter(Bool(true), pairs.size)
+    val dut = Module(new Decoder(bitpats))
+    dut.io.inst := Vec(insts.map(UInt(_)))(cnt)
+    when(dut.io.match_idx != cnt) { io.done := Bool(true); io.error := cnt }
+    when(wrap) { io.done := Bool(true) }
+  }
+
+  // Use a single Int to make both a specific instruction and a BitPat that will match it
+  val bitpatPair = for(seed <- Arbitrary.arbitrary[Int]) yield {
+    val rnd = new scala.util.Random(seed)
+    val bs = seed.toBinaryString
+    val bp = bs.map(if(rnd.nextBoolean) _ else "?").mkString
+    ("b"+bs, "b"+bp)
+  } 
+  def nPairs(n: Int) = Gen.containerOfN[List, (String,String)](n,bitpatPair)
+
+  property("BitPat wildcards should be usable in decoding") {
+    forAll(nPairs(16)){ (pairs: List[(String, String)]) =>
+      assert(execute{ new DecoderTester(pairs) })
+    }
+  }
+}