diff options
Diffstat (limited to 'src/main/scala/firrtl/passes/ExpandWhens.scala')
| -rw-r--r-- | src/main/scala/firrtl/passes/ExpandWhens.scala | 60 |
1 files changed, 29 insertions, 31 deletions
diff --git a/src/main/scala/firrtl/passes/ExpandWhens.scala b/src/main/scala/firrtl/passes/ExpandWhens.scala index 9136c913..560a1c1c 100644 --- a/src/main/scala/firrtl/passes/ExpandWhens.scala +++ b/src/main/scala/firrtl/passes/ExpandWhens.scala @@ -14,16 +14,16 @@ import collection.mutable import collection.immutable.ListSet /** Expand Whens -* -* This pass does the following things: -* $ - Remove last connect semantics -* $ - Remove conditional blocks -* $ - Eliminate concept of scoping -* $ - Consolidate attaches -* -* @note Assumes bulk connects and isInvalids have been expanded -* @note Assumes all references are declared -*/ + * + * This pass does the following things: + * $ - Remove last connect semantics + * $ - Remove conditional blocks + * $ - Eliminate concept of scoping + * $ - Consolidate attaches + * + * @note Assumes bulk connects and isInvalids have been expanded + * @note Assumes all references are declared + */ object ExpandWhens extends Pass { /** Returns circuit with when and last connection semantics resolved */ def run(c: Circuit): Circuit = { @@ -79,23 +79,22 @@ object ExpandWhens extends Pass { val infoMap: InfoMap = new InfoMap - /** - * Adds into into map, aggregates info into MultiInfo where necessary - * @param key serialized name of node - * @param info info being recorded - */ + /* Adds into into map, aggregates info into MultiInfo where necessary + * @param key serialized name of node + * @param info info being recorded + */ def saveInfo(key: String, info: Info): Unit = { infoMap(key) = infoMap(key) ++ info } - /** Removes connections/attaches from the statement - * Mutates namespace, simlist, nodes, attaches - * Mutates input netlist - * @param netlist maps references to their values for a given immediate scope - * @param defaults sequence of netlists of surrouding scopes, ordered closest to farthest - * @param p predicate so far, used to update simulation constructs - * @param s statement to expand - */ + /* Removes connections/attaches from the statement + * Mutates namespace, simlist, nodes, attaches + * Mutates input netlist + * @param netlist maps references to their values for a given immediate scope + * @param defaults sequence of netlists of surrouding scopes, ordered closest to farthest + * @param p predicate so far, used to update simulation constructs + * @param s statement to expand + */ def expandWhens(netlist: Netlist, defaults: Defaults, p: Expression) @@ -137,13 +136,13 @@ object ExpandWhens extends Pass { EmptyStmt // Expand conditionally, see comments below case sx: Conditionally => - /** 1) Recurse into conseq and alt with empty netlist, updated defaults, updated predicate - * 2) For each assigned reference (lvalue) in either conseq or alt, get merged value - * a) Find default value from defaults - * b) Create Mux, ValidIf or WInvalid, depending which (or both) conseq/alt assigned lvalue - * 3) If a merged value has been memoized, update netlist. Otherwise, memoize then update netlist. - * 4) Return conseq and alt declarations, followed by memoized nodes - */ + /* 1) Recurse into conseq and alt with empty netlist, updated defaults, updated predicate + * 2) For each assigned reference (lvalue) in either conseq or alt, get merged value + * a) Find default value from defaults + * b) Create Mux, ValidIf or WInvalid, depending which (or both) conseq/alt assigned lvalue + * 3) If a merged value has been memoized, update netlist. Otherwise, memoize then update netlist. + * 4) Return conseq and alt declarations, followed by memoized nodes + */ val conseqNetlist = new Netlist val altNetlist = new Netlist val conseqStmt = expandWhens(conseqNetlist, netlist +: defaults, AND(p, sx.pred))(sx.conseq) @@ -269,4 +268,3 @@ object ExpandWhens extends Pass { private def NOT(e: Expression) = DoPrim(Eq, Seq(e, zero), Nil, BoolType) } - |