Add assertion to prevent nonsense mod values (#2474)

test/unit/test_symbolic.py

@@ -402,6 +402,12 @@ class TestSymbolicSymbolicOps(unittest.TestCase):
     with self.assertRaises(AssertionError):
       lt3 = (x < 3)
 
+  def test_nested_variable_mod(self):
+    i = Variable("i", 1, 5)
+    idx0 = Variable("idx0", 0, i)
+    with self.assertRaises(AssertionError):
+      assert idx0 % 2 == idx0
+
   def test_num_node_mul_node(self):
     a = Variable("a", 1, 5)
     b = NumNode(2) * a

tinygrad/shape/symbolic.py

@@ -94,7 +94,7 @@ class Node:
       if self == b: return NumNode(0)
       if (b - self).min > 0 and self.min >= 0: return self # b - self simplifies the node
       raise RuntimeError(f"not supported: {self} % {b}")
-    assert b > 0
+    assert b > 0 and isinstance(self.max, int) and isinstance(self.min, int), 'not supported'
     if b == 1: return NumNode(0)
     if self.min >= 0 and self.max < b: return self
     if (self.min//b) == (self.max//b): return self - (b*(self.min//b))