public void visitCheckExpr(final CheckExpr expr) {
			// UGLY: We special case RC and UC to allow stack variables since
			// they do not change the operand stack at all. However, since
			// they do contain stack variables, we cannot hoist these
			// expressions, but we can one eliminate them so long as they
			// are replaced with stack variables rather than locals.

			if (isLeaf(expr.expr()) || (expr.expr() instanceof StackExpr)) {
				firstOrder = true;
			}
		}