first attack on creating a range api for chisel3

3 files changed, 68 insertions, 1 deletions

diff --git a/chiselFrontend/src/main/scala/chisel3/core/Bits.scala b/chiselFrontend/src/main/scala/chisel3/core/Bits.scala
index 4a09c70e..83733089 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/Bits.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/Bits.scala
@@ -563,6 +563,10 @@ private[core] sealed trait UIntFactory {
     result.binding = LitBinding()
     result
   }
+   /** Create a UInt with the specified range */
+  def apply(range: Range): UInt = {
+    width(range.getWidth)
+  }
 
   /** Create a UInt with a specified width - compatibility with Chisel2. */
   // NOTE: This resolves UInt(width = 32)
@@ -728,6 +732,11 @@ object SInt {
   /** Create an SInt literal with specified width. */
   def apply(value: BigInt, width: Width): SInt = Lit(value, width)
 
+  /** Create a SInt with the specified range */
+  def apply(range: Range): SInt = {
+    width(range.getWidth)
+  }
+
   def Lit(value: BigInt): SInt = Lit(value, Width())
   def Lit(value: BigInt, width: Int): SInt = Lit(value, Width(width))
    /** Create an SInt literal with specified width. */
diff --git a/chiselFrontend/src/main/scala/chisel3/internal/firrtl/IR.scala b/chiselFrontend/src/main/scala/chisel3/internal/firrtl/IR.scala
index 17b869f2..d463d78e 100644
--- a/chiselFrontend/src/main/scala/chisel3/internal/firrtl/IR.scala
+++ b/chiselFrontend/src/main/scala/chisel3/internal/firrtl/IR.scala
@@ -109,6 +109,63 @@ case class Index(imm: Arg, value: Arg) extends Arg {
   override def fullName(ctx: Component): String = s"${imm.fullName(ctx)}[${value.fullName(ctx)}]"
 }
 
+object Range {
+  def log2Up(value: BigInt): Int = {
+    require(value >= 0)
+    1 max (value-1).bitLength
+  }
+}
+
+/*sealed abstract class Range {
+
+}*/
+sealed trait Bound
+sealed trait NumericBound[T] extends Bound {
+  val value: T
+}
+sealed case class Open[T](value: T) extends NumericBound[T]
+sealed case class Closed[T](value: T) extends NumericBound[T]
+
+sealed trait Range {
+  val min: Bound
+  val max: Bound
+  def getWidth: Width
+}
+
+sealed trait KnownIntRange extends Range {
+  val min: NumericBound[Int]
+  val max: NumericBound[Int]
+
+  require( (min, max) match {
+    case (low, Open(high_val)) => low.value < high_val
+    case (Open(low_val), high) => low_val < high.value
+    case (Closed(low_val), Closed(high_val)) => low_val <= high_val
+  })
+}
+
+sealed case class KnownUIntRange(min: NumericBound[Int], max: NumericBound[Int]) extends KnownIntRange {
+  require (min.value >= 0)
+
+  def getWidth: Width = max match {
+    case Open(v) => Width(BigInt(v - 1).bitLength.max(1))
+    case Closed(v) => Width(BigInt(v).bitLength.max(1))
+  }
+}
+
+sealed case class KnownSIntRange(min: NumericBound[Int], max: NumericBound[Int]) extends KnownIntRange {
+
+  val maxWidth = max match {
+    case Open(v) => Width(BigInt(v - 1).bitLength + 1)
+    case Closed(v) => Width(BigInt(v).bitLength + 1)
+  }
+  val minWidth = min match {
+    case Open(v) => Width(BigInt(v + 1).bitLength + 1)
+    case Closed(v) => Width(BigInt(v).bitLength + 1)
+  }
+  def getWidth: Width = maxWidth.max(minWidth)
+
+}
+
 object Width {
   def apply(x: Int): Width = KnownWidth(x)
   def apply(): Width = UnknownWidth()
diff --git a/coreMacros/src/main/scala/chisel3/internal/RangeTransform.scala b/coreMacros/src/main/scala/chisel3/internal/RangeTransform.scala
index 20142d5d..ff5ba953 100644
--- a/coreMacros/src/main/scala/chisel3/internal/RangeTransform.scala
+++ b/coreMacros/src/main/scala/chisel3/internal/RangeTransform.scala
@@ -90,6 +90,7 @@ class RangeTransform(val c: Context) {
 
     c.warning(c.enclosingPosition, s"$startInclusive ${showRaw(minArg)} ${showRaw(maxArg)} $endInclusive")
 
-    q""
+    q"_root_.chisel3.internal.firrtl"
+
   }
 }