diff options
| author | Jim Lawson | 2016-06-20 11:08:46 -0700 |
|---|---|---|
| committer | Jim Lawson | 2016-06-20 11:08:46 -0700 |
| commit | d408d73a171535bd7c2ba9d0037c194022b8a62f (patch) | |
| tree | 81885a99ec56e89532bc3fa338f22b163dcc4d1f /src/main/scala/chisel3/util/Conditional.scala | |
| parent | b5a534914795d9d17f4dfe623525f1b804e4c60f (diff) | |
Rename chisel3 package.
Diffstat (limited to 'src/main/scala/chisel3/util/Conditional.scala')
| -rw-r--r-- | src/main/scala/chisel3/util/Conditional.scala | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/src/main/scala/chisel3/util/Conditional.scala b/src/main/scala/chisel3/util/Conditional.scala new file mode 100644 index 00000000..01c12799 --- /dev/null +++ b/src/main/scala/chisel3/util/Conditional.scala @@ -0,0 +1,73 @@ +// See LICENSE for license details. + +/** Conditional blocks. + */ + +package chisel.util + +import scala.language.reflectiveCalls +import scala.language.experimental.macros +import scala.reflect.runtime.universe._ +import scala.reflect.macros.blackbox._ + +import chisel._ + +/** This is identical to [[Chisel.when when]] with the condition inverted */ +object unless { // scalastyle:ignore object.name + def apply(c: Bool)(block: => Unit) { + when (!c) { block } + } +} + +class SwitchContext[T <: Bits](cond: T) { + def is(v: Iterable[T])(block: => Unit) { + if (!v.isEmpty) when (v.map(_.asUInt === cond.asUInt).reduce(_||_)) { block } + } + def is(v: T)(block: => Unit) { is(Seq(v))(block) } + def is(v: T, vr: T*)(block: => Unit) { is(v :: vr.toList)(block) } +} + +/** An object for separate cases in [[Chisel.switch switch]] + * It is equivalent to a [[Chisel.when$ when]] block comparing to the condition + * Use outside of a switch statement is illegal */ +object is { // scalastyle:ignore object.name + // Begin deprecation of non-type-parameterized is statements. + def apply(v: Iterable[Bits])(block: => Unit) { + require(false, "The 'is' keyword may not be used outside of a switch.") + } + + def apply(v: Bits)(block: => Unit) { + require(false, "The 'is' keyword may not be used outside of a switch.") + } + + def apply(v: Bits, vr: Bits*)(block: => Unit) { + require(false, "The 'is' keyword may not be used outside of a switch.") + } +} + +/** Conditional logic to form a switch block + * @example + * {{{ ... // default values here + * switch ( myState ) { + * is( state1 ) { + * ... // some logic here + * } + * is( state2 ) { + * ... // some logic here + * } + * } }}}*/ +object switch { // scalastyle:ignore object.name + def apply[T <: Bits](cond: T)(x: => Unit): Unit = macro impl + def impl(c: Context)(cond: c.Tree)(x: c.Tree): c.Tree = { import c.universe._ + val sc = c.universe.internal.reificationSupport.freshTermName("sc") + def extractIsStatement(tree: Tree): List[c.universe.Tree] = tree match { + // TODO: remove when Chisel compatibility package is removed + case q"Chisel.`package`.is.apply( ..$params )( ..$body )" => List(q"$sc.is( ..$params )( ..$body )") + case q"chisel.util.is.apply( ..$params )( ..$body )" => List(q"$sc.is( ..$params )( ..$body )") + case b => throw new Exception(s"Cannot include blocks that do not begin with is() in switch.") + } + val q"..$body" = x + val ises = body.flatMap(extractIsStatement(_)) + q"""{ val $sc = new SwitchContext($cond); ..$ises }""" + } +} |
