diff options
| author | Jack Koenig | 2018-04-10 21:24:49 -0700 |
|---|---|---|
| committer | GitHub | 2018-04-10 21:24:49 -0700 |
| commit | 0c93a121c109c3e167d80173dbfe8c2e355b30ef (patch) | |
| tree | 1da105cf6ff46a8badb0ec23b27bbd5fedc6b8b4 /src/main | |
| parent | 1d4914c396881c66aceb47d5cdd8740ad9a5be26 (diff) | |
Fix bug in Constant Propagation for registers propped to zero (#787)
It wasn't properly padding the width of the constant zero.
Also add a test that shows the buggy behavior.
Diffstat (limited to 'src/main')
| -rw-r--r-- | src/main/scala/firrtl/transforms/ConstantPropagation.scala | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/main/scala/firrtl/transforms/ConstantPropagation.scala b/src/main/scala/firrtl/transforms/ConstantPropagation.scala index 2def130c..c417357b 100644 --- a/src/main/scala/firrtl/transforms/ConstantPropagation.scala +++ b/src/main/scala/firrtl/transforms/ConstantPropagation.scala @@ -379,7 +379,8 @@ class ConstantPropagation extends Transform { case Mux(_, tval: Literal, fval: WRef, _) if weq(lref, fval) => nodeMap(lname) = constPropExpression(nodeMap, instMap, constSubOutputs)(pad(tval, ltpe)) case WRef(`lname`, _,_,_) => // If a register is connected to itself, propagate zero - nodeMap(lname) = passes.RemoveValidIf.getGroundZero(ltpe) + val zero = passes.RemoveValidIf.getGroundZero(ltpe) + nodeMap(lname) = constPropExpression(nodeMap, instMap, constSubOutputs)(pad(zero, ltpe)) case _ => } // Mark instance inputs connected to a constant |