diff options
Diffstat (limited to 'src/main/scala/firrtl/transforms/ConstantPropagation.scala')
| -rw-r--r-- | src/main/scala/firrtl/transforms/ConstantPropagation.scala | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/src/main/scala/firrtl/transforms/ConstantPropagation.scala b/src/main/scala/firrtl/transforms/ConstantPropagation.scala index 6618312a..fdaa7112 100644 --- a/src/main/scala/firrtl/transforms/ConstantPropagation.scala +++ b/src/main/scala/firrtl/transforms/ConstantPropagation.scala @@ -350,6 +350,8 @@ class ConstantPropagation extends Transform with ResolvedAnnotationPaths { // Keep track of any submodule inputs we drive with a constant // (can have more than 1 of the same submodule) val constSubInputs = mutable.HashMap.empty[String, mutable.HashMap[String, Seq[Literal]]] + // AsyncReset registers don't have reset turned into a mux so we must be careful + val asyncResetRegs = mutable.HashSet.empty[String] // Copy constant mapping for constant inputs (except ones marked dontTouch!) nodeMap ++= constInputs.filterNot { case (pname, _) => dontTouches.contains(pname) } @@ -405,6 +407,8 @@ class ConstantPropagation extends Transform with ResolvedAnnotationPaths { // Record things that should be propagated stmtx match { case x: DefNode if !dontTouches.contains(x.name) => propagateRef(x.name, x.value) + case reg: DefRegister if reg.reset.tpe == AsyncResetType => + asyncResetRegs += reg.name case Connect(_, WRef(wname, wtpe, WireKind, _), expr: Literal) if !dontTouches.contains(wname) => val exprx = constPropExpression(nodeMap, instMap, constSubOutputs)(pad(expr, wtpe)) propagateRef(wname, exprx) @@ -414,7 +418,7 @@ class ConstantPropagation extends Transform with ResolvedAnnotationPaths { constOutputs(pname) = paddedLit // Const prop registers that are driven by a mux tree containing only instances of one constant or self-assigns // This requires that reset has been made explicit - case Connect(_, lref @ WRef(lname, ltpe, RegKind, _), rhs) if !dontTouches.contains(lname) => + case Connect(_, lref @ WRef(lname, ltpe, RegKind, _), rhs) if !dontTouches(lname) && !asyncResetRegs(lname) => /** Checks if an RHS expression e of a register assignment is convertible to a constant assignment. * Here, this means that e must be 1) a literal, 2) a self-connect, or 3) a mux tree of cases (1) and (2). * In case (3), it also recursively checks that the two mux cases are convertible to constants and |