fast compare for lazyop (#2893)

test/test_fusion_op.py

@@ -27,12 +27,26 @@ class TestFusionOp(unittest.TestCase):
   def test_recursive_add(self):
     st = time.perf_counter()
     a = Tensor([1,2,3,4])
-    for _ in range(20): a = a + a
+    for _ in range(24): a = a + a
     sched = create_schedule([a.lazydata], None)
     ji = lower_schedule_item(sched[-1])
-    et = time.perf_counter()
+    self.assertLess(time.perf_counter()-st, 1.0)
-    self.assertLess(et-st, 10.0)
     assert isinstance(ji, InterpretedASTRunner) or len(ji.prg) < 5000
 
+  def test_recursive_add_cmp(self):
+    st = time.perf_counter()
+    a = Tensor([1,2,3,4])
+    for _ in range(24): a = a + a
+    sched1 = create_schedule([a.lazydata], None)
+    b = Tensor([1,2,3,4])
+    for _ in range(24): b = b + b
+    sched2 = create_schedule([b.lazydata], None)
+    c = Tensor([1,2,3,4])
+    for _ in range(23): c = c + c
+    sched3 = create_schedule([c.lazydata], None)
+    assert sched1[-1].ast == sched2[-1].ast
+    assert sched1[-1].ast != sched3[-1].ast
+    self.assertLess(time.perf_counter()-st, 1.0)
+
 if __name__ == '__main__':
   unittest.main(verbosity=2)

tinygrad/ops.py

@@ -45,11 +45,18 @@ class ScheduleItem:
   inputs: Tuple[LazyBuffer, ...]
   var_vals: Dict[Variable, int]
 
-@dataclass(frozen=True)
+@dataclass(frozen=True, eq=False)
 class LazyOp:
   op: Op
   src: Tuple[LazyOp, ...] = ()
   arg: Any = None
+  def cached_compare(self, x, context):
+    if id(self) == id(x): return True
+    if self.op != x.op or self.arg != x.arg or len(self.src) != len(x.src): return False
+    if (self,x) in context: return context[(self,x)]
+    ret = context[self,x] = all(a.cached_compare(b, context) for a,b in zip(self.src, x.src))
+    return ret
+  def __eq__(self, x): return self.cached_compare(x, context={})
   def __repr__(self): return f"LazyOp(op={self.op}, src={self.src}, arg={self.arg})"
   @functools.cached_property
   def hash(self): return hash((self.op, self.src, self.arg))