Limit number of nonminimal_bool ops

clippy_lints/src/booleans.rs

@@ -477,14 +477,12 @@ impl<'a, 'tcx> NonminimalBoolVisitor<'a, 'tcx> {
             cx: self.cx,
         };
         if let Ok(expr) = h2q.run(e) {
-            if h2q.terminals.len() > 8 {
-                // QMC has exponentially slow behavior as the number of terminals increases
-                // 8 is reasonable, it takes approximately 0.2 seconds.
-                // See #825
+            let stats = terminal_stats(&expr);
+            if stats.ops > 7 {
+                // QMC has exponentially slow behavior as the number of ops increases.
+                // See #825, #13206
                 return;
             }
-
-            let stats = terminal_stats(&expr);
             let mut simplified = expr.simplify();
             for simple in Bool::Not(Box::new(expr)).simplify() {
                 match simple {

tests/ui/nonminimal_bool.rs

@@ -177,3 +177,9 @@ fn issue_12371(x: usize) -> bool {
     // Should not warn!
     !x != 0
 }
+
+// Not linted because it is slow to do so
+// https://github.com/rust-lang/rust-clippy/issues/13206
+fn many_ops(a: bool, b: bool, c: bool, d: bool, e: bool, f: bool) -> bool {
+    (a && c && f) || (!a && b && !d) || (!b && !c && !e) || (d && e && !f)
+}