Revert "Better div nesting (#11811)"

This reverts commit 952f729b07.

test/unit/test_uop_symbolic.py

@@ -483,7 +483,9 @@ class TestSymbolic(unittest.TestCase):
     lidx2 = Variable("lidx2", 0, 3)
     alu0 = gidx2*640+gidx1*160+(gidx0//5)*2+lidx0*320+lidx1*10
     self.helper_test_variable((alu0+lidx2*2+1)//20, 0, 8192,
-                              ("((((gidx1*8)+(gidx2*32))+(lidx0*16))+(((lidx2+(gidx0//5))+(lidx1*5))//10))",))
+                              ("((((((gidx0//5)+lidx2)//5)+lidx1)//2)+(((gidx2*32)+(gidx1*8))+(lidx0*16)))",
+                               "(((lidx1+((lidx2+(gidx0//5))//5))//2)+((gidx2*32)+((gidx1*8)+(lidx0*16))))",
+                               "((((gidx1*8)+(gidx2*32))+(lidx0*16))+((lidx1+((lidx2+(gidx0//5))//5))//2))"))
 
   def test_sum_div_complex2(self):
     gidx0 = Variable("gidx0", 0, 7)
@@ -497,8 +499,8 @@ class TestSymbolic(unittest.TestCase):
     gidx0 = Variable("gidx0", 0, 7)
     lidx2 = Variable("lidx2", 0, 12)
     lidx3 = Variable("lidx3", 0, 1)
-    self.helper_test_variable((gidx0*4+lidx2*2+lidx3)//12, 0, 4, ("((lidx2+(gidx0*2))//6)"))
-    self.helper_test_variable((lidx2*2+gidx0*4+lidx3)//12, 0, 4, ("((lidx2+(gidx0*2))//6)"))
+    self.helper_test_variable((gidx0*4+lidx2*2+lidx3)//12, 0, 4, ("(((lidx2//2)+gidx0)//3)", "((gidx0+(lidx2//2))//3)"))
+    self.helper_test_variable((lidx2*2+gidx0*4+lidx3)//12, 0, 4, ("(((lidx2//2)+gidx0)//3)", "((gidx0+(lidx2//2))//3)"))
 
   def test_sum_mul_distribute(self):
     gidx0 = Variable("gidx0", 0, 7)

tinygrad/uop/symbolic.py

@@ -202,8 +202,7 @@ def nest_div_by_smallest_factor(d: UOp, x: UOp, y: UOp) -> UOp|None:
   # TODO: there are better ways to pick `div`, this sometimes adds extra divisions
   # TODO: add same optimization for mod
   div = min([y.arg]+[abs(f) for f in factors if abs(f) > 1 and (c%f)==0])
-  if (1 < div < c) and (newxs:=fold_divmod_congruence(newx:=(x//div), x, y.const_like(div))) is not None and x.vmin>=0 and newx.vmin>=0:
-    return newxs//(c//div)
+  if (1 < div < c) and (newxs:=(newx:=(x//div)).simplify()) is not newx and x.vmin>=0 and newx.vmin>=0: return newxs//(c//div)
   return None
 
 def simplify_remainder(d: UOp, x: UOp, y: UOp) -> UOp|None: