private void cleanupEdge(final Block src, final Block dst) {
		dst.visit(new TreeVisitor() {
			public void visitPhiJoinStmt(final PhiJoinStmt stmt) {
				final Expr operand = stmt.operandAt(src);

				if (operand != null) {
					operand.cleanup();

					// Remove the operand associated with src
					// from a PhiJoinStmt
					stmt.setOperandAt(src, null);
				}
			}

			public void visitStmt(final Stmt stmt) {
			}
		});
	}