Add a helper method to unpack IEEE floats

src/main/scala/tile/FPU.scala

@@ -193,7 +193,8 @@ case class FType(exp: Int, sig: Int) {
   def ieeeWidth = exp + sig
   def recodedWidth = ieeeWidth + 1
 
-  def qNaN = UInt((BigInt(7) << (exp + sig - 3)) + (BigInt(1) << (sig - 2)), exp + sig + 1)
+  def ieeeQNaN = UInt((BigInt(1) << (ieeeWidth - 1)) - (BigInt(1) << (sig - 2)), ieeeWidth)
+  def qNaN = UInt((BigInt(7) << (exp + sig - 3)) + (BigInt(1) << (sig - 2)), recodedWidth)
   def isNaN(x: UInt) = x(sig + exp - 1, sig + exp - 3).andR
   def isSNaN(x: UInt) = isNaN(x) && !x(sig - 2)
 
@@ -231,6 +232,19 @@ case class FType(exp: Int, sig: Int) {
     Cat(sign, expOut, fractOut)
   }
 
+  private def ieeeBundle = {
+    val expWidth = exp
+    class IEEEBundle extends Bundle {
+      val sign = Bool()
+      val exp = UInt(expWidth.W)
+      val sig = UInt((ieeeWidth-expWidth-1).W)
+      override def cloneType = new IEEEBundle().asInstanceOf[this.type]
+    }
+    new IEEEBundle
+  }
+
+  def unpackIEEE(x: UInt) = x.asTypeOf(ieeeBundle)
+
   def recode(x: UInt) = hardfloat.recFNFromFN(exp, sig, x)
   def ieee(x: UInt) = hardfloat.fNFromRecFN(exp, sig, x)
 }