API change: out-of-bounds vec accesses now invalid, not first element (#685)

[skip formal checks]
Generate nicer name for remove accesses

4 files changed, 38 insertions, 5 deletions

diff --git a/src/main/scala/firrtl/LoweringCompilers.scala b/src/main/scala/firrtl/LoweringCompilers.scala
index f032868a..57aa1533 100644
--- a/src/main/scala/firrtl/LoweringCompilers.scala
+++ b/src/main/scala/firrtl/LoweringCompilers.scala
@@ -59,6 +59,7 @@ class HighFirrtlToMiddleFirrtl extends CoreTransform {
     passes.ReplaceAccesses,
     passes.ExpandConnects,
     passes.RemoveAccesses,
+    passes.Uniquify,
     passes.ExpandWhens,
     passes.CheckInitialization,
     passes.ResolveKinds,
diff --git a/src/main/scala/firrtl/Namespace.scala b/src/main/scala/firrtl/Namespace.scala
index cf8472a6..9e1cae67 100644
--- a/src/main/scala/firrtl/Namespace.scala
+++ b/src/main/scala/firrtl/Namespace.scala
@@ -40,6 +40,9 @@ class Namespace private {
   }
 }
 
+/* TODO(azidar): Make Namespace return unique names that will not conflict with expanded
+ * names after LowerTypes expands names (like the Uniquify pass).
+ */
 object Namespace {
   // Initializes a namespace from a Module
   def apply(m: DefModule): Namespace = {
diff --git a/src/main/scala/firrtl/Utils.scala b/src/main/scala/firrtl/Utils.scala
index c9659644..76f58f30 100644
--- a/src/main/scala/firrtl/Utils.scala
+++ b/src/main/scala/firrtl/Utils.scala
@@ -130,6 +130,7 @@ class FIRRTLException(val str: String) extends Exception(str)
 object Utils extends LazyLogging {
   def throwInternalError =
     error("Internal Error! Please file an issue at https://github.com/ucb-bar/firrtl/issues")
+
   private[firrtl] def time[R](block: => R): (Double, R) = {
     val t0 = System.nanoTime()
     val result = block
@@ -139,7 +140,7 @@ object Utils extends LazyLogging {
   }
 
   /** Removes all [[firrtl.ir.EmptyStmt]] statements and condenses
-   * [[firrtl.ir.Block]] statements.
+    * [[firrtl.ir.Block]] statements.
     */
   def squashEmpty(s: Statement): Statement = s map squashEmpty match {
     case Block(stmts) =>
@@ -152,6 +153,31 @@ object Utils extends LazyLogging {
     case sx => sx
   }
 
+  /** Provide a nice name to create a temporary **/
+  def niceName(e: Expression): String = niceName(1)(e)
+  def niceName(depth: Int)(e: Expression): String = {
+    e match {
+      case WRef(name, _, _, _) if name(0) == '_' => name
+      case WRef(name, _, _, _) => "_" + name
+      case WSubAccess(expr, index, _, _) if depth <= 0 => niceName(depth)(expr)
+      case WSubAccess(expr, index, _, _) => niceName(depth)(expr) + niceName(depth - 1)(index)
+      case WSubField(expr, field, _, _) => niceName(depth)(expr) + "_" + field
+      case WSubIndex(expr, index, _, _) => niceName(depth)(expr) + "_" + index
+      case Reference(name, _) if name(0) == '_' => name
+      case Reference(name, _) => "_" + name
+      case SubAccess(expr, index,  _) if depth <= 0 => niceName(depth)(expr)
+      case SubAccess(expr, index,  _) => niceName(depth)(expr) + niceName(depth - 1)(index)
+      case SubField(expr, field, _) => niceName(depth)(expr) + "_" + field
+      case SubIndex(expr, index, _) => niceName(depth)(expr) + "_" + index
+      case DoPrim(op, args, consts, _) if depth <= 0 => "_" + op
+      case DoPrim(op, args, consts, _) => "_" + op + (args.map(niceName(depth - 1)) ++ consts.map("_" + _)).mkString("")
+      case Mux(cond, tval, fval, _) if depth <= 0 => "_mux"
+      case Mux(cond, tval, fval, _) => "_mux" + Seq(cond, tval, fval).map(niceName(depth - 1)).mkString("")
+      case UIntLiteral(value, _) => "_" + value
+      case SIntLiteral(value, _) => "_" + value
+    }
+  }
+
   /** Indent the results of [[ir.FirrtlNode.serialize]] */
   def indent(str: String) = str replaceAllLiterally ("\n", "\n  ")
 
diff --git a/src/main/scala/firrtl/passes/RemoveAccesses.scala b/src/main/scala/firrtl/passes/RemoveAccesses.scala
index 253e6a15..37b92a9e 100644
--- a/src/main/scala/firrtl/passes/RemoveAccesses.scala
+++ b/src/main/scala/firrtl/passes/RemoveAccesses.scala
@@ -15,10 +15,12 @@ import scala.collection.mutable
   */
 object RemoveAccesses extends Pass {
   private def AND(e1: Expression, e2: Expression) =
-    DoPrim(And, Seq(e1, e2), Nil, BoolType)
+    if(e1 == one) e2
+    else if(e2 == one) e1
+    else DoPrim(And, Seq(e1, e2), Nil, BoolType)
 
   private def EQV(e1: Expression, e2: Expression): Expression =
-    DoPrim(Eq, Seq(e1, e2), Nil, e1.tpe)
+    DoPrim(Eq, Seq(e1, e2), Nil, BoolType)
 
   /** Container for a base expression and its corresponding guard
     */
@@ -82,7 +84,7 @@ object RemoveAccesses extends Pass {
       val namespace = Namespace(m)
       def onStmt(s: Statement): Statement = {
         def create_temp(e: Expression): (Statement, Expression) = {
-          val n = namespace.newTemp
+          val n = namespace.newName(niceName(e))
           (DefWire(get_info(s), n, e.tpe), WRef(n, e.tpe, kind(e), gender(e)))
         }
 
@@ -101,7 +103,8 @@ object RemoveAccesses extends Pass {
                 stmts += wire
                 rs.zipWithIndex foreach {
                   case (x, i) if i < temps.size =>
-                    stmts += Connect(get_info(s),getTemp(i),x.base)
+                    stmts += IsInvalid(get_info(s),getTemp(i))
+                    stmts += Conditionally(get_info(s),x.guard,Connect(get_info(s),getTemp(i),x.base),EmptyStmt)
                   case (x, i) =>
                     stmts += Conditionally(get_info(s),x.guard,Connect(get_info(s),getTemp(i),x.base),EmptyStmt)
                 }