Vec.reduceTree leads to java.lang.OutOfMemoryError

In my code, the following usage of reduceTree will lead to OutOfMemoryError when the parameter dspXn grows from 16 to 32. The problem disappeared when I change the reduceTree to reduceLeft.

`io.convResult := VecInit((for(i<- 0 until 4)
yield VecInit((for(j<-0 until dspXn)
yield dspArray(j).result(i))).reduceTree(_+&_) ))`

Java runtime memory is enlarged using the following configuration. But the problem remains the same as long as reduceTree is used.
`export JAVA_OPTS="-XX:+CMSClassUnloadingEnabled -XX:-UseGCOverheadLimit -XX:+UseConcMarkSweepGC -Xmx32G -Xmx16G -XX:MaxPermSize=1G -Xss16M"`

Seems there is some memory leakage in the implementation of reduceTree?