The MergeCircuitsPass assumed that the only quantum operation between quir.call_circuits operations would be quir.barriers. This assumption failed with the BreakResetsPass which currently inserts quir.measure and quir.call_gate @x in the main function.
One way to fix this would be to adjust BreakResetsPass to be --enable-circuits aware. The alternative implemented here is to handle operations other than barriers between quir.circuit_ops and test for qubit overlap in the same way currently being applied to quir.barriers.
This alternative was chosen so that existing and future passes would not be required to be "quir.circuit" aware and therefore MergeCircuitsPass would be more robust to that situation.
The
MergeCircuitsPassassumed that the only quantum operation betweenquir.call_circuitsoperations would bequir.barriers. This assumption failed with theBreakResetsPasswhich currently insertsquir.measureandquir.call_gate @xin themainfunction.One way to fix this would be to adjust
BreakResetsPassto be--enable-circuitsaware. The alternative implemented here is to handle operations other than barriers betweenquir.circuit_opsand test for qubit overlap in the same way currently being applied toquir.barriers.This alternative was chosen so that existing and future passes would not be required to be "quir.circuit" aware and therefore
MergeCircuitsPasswould be more robust to that situation.