different valid order (#7589)

in simplify_valid, we start with valids that are in others' parent so the others is more likely to be simplified

test/unit/test_simplify_valid_idx.py

@@ -1,4 +1,4 @@
-import unittest
+import unittest, itertools
 from typing import Tuple
 
 from tinygrad.codegen.uopgraph import full_graph_rewrite, is_increasing
@@ -79,6 +79,26 @@ class TestValidIdxSimplification(unittest.TestCase):
     valid = alu0.lt(57) & alu0.ge(1)
     self.assertIsNone(simplify_valid(valid))
 
+  def test_valid_order_matters1(self):
+    ridx0 = Range(0, 2)
+    v0 = ridx0.lt(1)
+    v1 = ((ridx0*5+1)%6).lt(5)
+    self.assertEqual(simplify_valid(v0&v1).render(), "(ridx0<1)")
+    self.assertEqual(simplify_valid(v1&v0).render(), "(ridx0<1)")
+
+  def test_valid_order_matters2(self):
+    gidx0 = Special("gidx0", 13)
+    gidx1 = Special("gidx1", 13)
+    ridx0 = Range(0, 4)
+    alu0 = (gidx1+(ridx0*13))
+    v0 = ((gidx0+11)%14).lt(11)
+    v1 = ((alu0+((gidx0+39)//42))%14).lt(11)
+    v2 = gidx0.lt(3)
+    v3 = alu0.lt(42)
+
+    for v in itertools.permutations([v0,v1,v2,v3]):
+      self.assertEqual(simplify_valid(v[0]&v[1]&v[2]&v[3]).render(), "False")
+
 class TestImageSimplification(unittest.TestCase):
   def check(self, load, svalid, sidx0, sidx1):
     load = full_graph_rewrite(load.sink()).src[0]