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Diffstat (limited to 'src/main/scala/firrtl/Utils.scala')
| -rw-r--r-- | src/main/scala/firrtl/Utils.scala | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/src/main/scala/firrtl/Utils.scala b/src/main/scala/firrtl/Utils.scala index 30dff01c..f54d8cd6 100644 --- a/src/main/scala/firrtl/Utils.scala +++ b/src/main/scala/firrtl/Utils.scala @@ -580,6 +580,41 @@ object Utils extends LazyLogging { case _ => NoInfo }} + /** Splits an Expression into root Ref and tail + * + * @example + * Given: SubField(SubIndex(SubField(Ref("a", UIntType(IntWidth(32))), "b"), 2), "c") + * Returns: (Ref("a"), SubField(SubIndex(Ref("b"), 2), "c")) + * a.b[2].c -> (a, b[2].c) + * @example + * Given: SubField(SubIndex(Ref("b"), 2), "c") + * Returns: (Ref("b"), SubField(SubIndex(EmptyExpression, 2), "c")) + * b[2].c -> (b, EMPTY[2].c) + * @note This function only supports WRef, WSubField, and WSubIndex + */ + def splitRef(e: Expression): (WRef, Expression) = e match { + case e: WRef => (e, EmptyExpression) + case e: WSubIndex => + val (root, tail) = splitRef(e.exp) + (root, WSubIndex(tail, e.value, e.tpe, e.gender)) + case e: WSubField => + val (root, tail) = splitRef(e.exp) + tail match { + case EmptyExpression => (root, WRef(e.name, e.tpe, root.kind, e.gender)) + case exp => (root, WSubField(tail, e.name, e.tpe, e.gender)) + } + } + + /** Adds a root reference to some SubField/SubIndex chain */ + def mergeRef(root: WRef, body: Expression): Expression = body match { + case e: WRef => + WSubField(root, e.name, e.tpe, e.gender) + case e: WSubIndex => + WSubIndex(mergeRef(root, e.exp), e.value, e.tpe, e.gender) + case e: WSubField => + WSubField(mergeRef(root, e.exp), e.name, e.tpe, e.gender) + case EmptyExpression => root + } // =============== RECURISVE MAPPERS =================== def mapr (f: Width => Width, t:Type) : Type = { |