diff options
Diffstat (limited to 'chapter02/src/main/java')
| -rw-r--r-- | chapter02/src/main/java/com/seaofnodes/simple/node/Node.java | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/chapter02/src/main/java/com/seaofnodes/simple/node/Node.java b/chapter02/src/main/java/com/seaofnodes/simple/node/Node.java index 43dea8e1..7c39083e 100644 --- a/chapter02/src/main/java/com/seaofnodes/simple/node/Node.java +++ b/chapter02/src/main/java/com/seaofnodes/simple/node/Node.java @@ -154,6 +154,12 @@ public abstract class Node { */ void set_def(int idx, Node new_def ) { Node old_def = in(idx); + if( old_def == new_def ) return; // No change + // If new def is not null, add the corresponding def->use edge + // This needs to happen before removing the old node's def->use edge as + // the new_def might get killed if the old node kills it recursively. + if( new_def != null ) + new_def._outputs.add(this); if( old_def != null ) { // If the old def exists, remove a use->def edge ArrayList<Node> outs = old_def._outputs; int lidx = outs.size()-1; // Last index @@ -168,9 +174,6 @@ public abstract class Node { } // Set the new_def over the old (killed) edge _inputs.set(idx,new_def); - // If new def is not null, add the corresponding use->def edge - if( new_def != null ) - new_def._outputs.add(this); } |