1 files changed, 118 insertions, 0 deletions
diff --git a/src/test/scala/firrtlTests/fixed/FixedPointMathSpec.scala b/src/test/scala/firrtlTests/fixed/FixedPointMathSpec.scala
new file mode 100644
index 00000000..85f34606
--- /dev/null
+++ b/src/test/scala/firrtlTests/fixed/FixedPointMathSpec.scala
@@ -0,0 +1,118 @@
+// See LICENSE for license details.
+
+package firrtlTests.fixed
+
+import java.io.StringWriter
+
+import firrtl.Annotations.AnnotationMap
+import firrtl.{LowFirrtlCompiler, Parser}
+import firrtl.Parser.IgnoreInfo
+import firrtlTests.FirrtlFlatSpec
+
+class FixedPointMathSpec extends FirrtlFlatSpec {
+  def parse (input:String) = Parser.parse(input.split("\n").toIterator, IgnoreInfo)
+
+  "Fixed types" should "parse" in {
+    val SumPattern        = """.*output sum.*<(\d+)>.*.*""".r
+    val ProductPattern    = """.*output product.*<(\d+)>.*""".r
+    val DifferencePattern = """.*output difference.*<(\d+)>.*""".r
+
+    val AssignPattern     = """\s*(\w+) <= (\w+)\((.*)\)\s*""".r
+
+    for {
+      bits1        <- 1 to 4
+//      binaryPoint1 <- -4 to 4
+      binaryPoint1 <- 1 to 4
+      bits2        <- 1 to 4
+//      binaryPoint2 <- -4 to 4
+      binaryPoint2 <- 1 to 4
+    } {
+      val input =
+        s"""circuit Unit :
+        |  module Unit :
+        |    input  a : Fixed<$bits1><<$binaryPoint1>>
+        |    input  b : Fixed<$bits2><<$binaryPoint2>>
+        |    output sum        : Fixed
+        |    output product    : Fixed
+        |    output difference : Fixed
+        |    sum        <= add(a, b)
+        |    product    <= mul(a, b)
+        |    difference <= sub(a, b)
+        |    """.
+          stripMargin
+
+      val lowerer = new LowFirrtlCompiler
+
+      val writer = new StringWriter()
+
+      lowerer.compile(parse(input), new AnnotationMap(Seq.empty), writer)
+
+      val output = writer.toString.split("\n")
+
+      def config = s"($bits1,$binaryPoint1)($bits2,$binaryPoint2)"
+
+      def inferredAddWidth: Int = {
+        val binaryDifference = binaryPoint1 - binaryPoint2
+        val (newW1, newW2) = if(binaryDifference > 0) {
+          (bits1, bits2 + binaryDifference)
+        } else {
+          (bits1 + binaryDifference.abs, bits2)
+        }
+        newW1.max(newW2) + 1
+      }
+
+      println(s"Test for configuratio $config")
+
+      for(line <- output) {
+        line  match {
+          case SumPattern(varWidth)     =>
+            assert(varWidth.toInt === inferredAddWidth, s"$config sum sint bits wrong for $line")
+          case ProductPattern(varWidth) =>
+            assert(varWidth.toInt === bits1 + bits2, s"$config product bits wrong for $line")
+          case DifferencePattern(varWidth)     =>
+            assert(varWidth.toInt === inferredAddWidth, s"$config difference bits wrong for $line")
+          case AssignPattern(varName, operation, args) =>
+            varName match {
+              case "sum" =>
+                assert(operation === "add", s"var sum should be result of an add in $line")
+                if (binaryPoint1 > binaryPoint2) {
+                  assert(!args.contains("shl(a"), s"$config first arg should be just a in $line")
+                  assert(args.contains(s"shl(b, ${binaryPoint1 - binaryPoint2})"),
+                    s"$config second arg incorrect in $line")
+                } else if (binaryPoint1 < binaryPoint2) {
+                  assert(args.contains(s"shl(a, ${(binaryPoint1 - binaryPoint2).abs})"),
+                    s"$config second arg incorrect in $line")
+                  assert(!args.contains("shl(b"), s"$config second arg should be just b in $line")
+                } else {
+                  assert(!args.contains("shl(a"), s"$config first arg should be just a in $line")
+                  assert(!args.contains("shl(b"), s"$config second arg should be just b in $line")
+                }
+              case "product" =>
+                assert(operation === "mul", s"var sum should be result of an add in $line")
+                assert(!args.contains("shl(a"), s"$config first arg should be just a in $line")
+                assert(!args.contains("shl(b"), s"$config second arg should be just b in $line")
+              case "difference" =>
+                assert(operation === "sub", s"var difference should be result of an sub in $line")
+                if (binaryPoint1 > binaryPoint2) {
+                  assert(!args.contains("shl(a"), s"$config first arg should be just a in $line")
+                  assert(args.contains(s"shl(b, ${binaryPoint1 - binaryPoint2})"),
+                    s"$config second arg incorrect in $line")
+                } else if (binaryPoint1 < binaryPoint2) {
+                  assert(args.contains(s"shl(a, ${(binaryPoint1 - binaryPoint2).abs})"),
+                    s"$config second arg incorrect in $line")
+                  assert(!args.contains("shl(b"), s"$config second arg should be just b in $line")
+                } else {
+                  assert(!args.contains("shl(a"), s"$config first arg should be just a in $line")
+                  assert(!args.contains("shl(b"), s"$config second arg should be just b in $line")
+                }
+              case _ =>
+            }
+          case _ =>
+//            println(s"No pattern found for ${line}")
+        }
+      }
+
+      println(writer.toString)
+    }
+  }
+}