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]

tinygrad/ops.py

@@ -992,10 +992,16 @@ def uop_given_valid(valid:UOp, uop:UOp) -> Optional[UOp]:
 
   return uop
 
+def _valid_priority(v: UOp, valids:List[UOp]):
+  # we want valid that's in other valids' parents to be first, so it's more likely the other valids get simplified
+  try: return sum(-1 if parse_valid(v)[0] in other.parents else 0 for other in valids)
+  except ValueError: return 0
+
 def simplify_valid(valid:UOp) -> Optional[UOp]:
   ret:List[UOp] = []
   something_changed = False
-  for stmt in split_uop(valid, BinaryOps.AND):
+  valids = list(split_uop(valid, Ops.AND))
+  for stmt in sorted(valids, key=lambda v: _valid_priority(v, valids)):
     ret.append(newstmt if ret and (newstmt:=uop_given_valid(functools.reduce(operator.and_, ret), stmt)) is not None else stmt)
     if ret[-1] is not stmt: something_changed = True
   return functools.reduce(operator.and_, ret) if something_changed else None