diff --git a/test/test_pattern_matcher.py b/test/test_pattern_matcher.py
new file mode 100644
index 0000000000..2ea730ca8d
--- /dev/null
+++ b/test/test_pattern_matcher.py
@@ -0,0 +1,70 @@
+import unittest
+from tinygrad.dtype import dtypes
+from tinygrad.ops import BinaryOps
+from tinygrad.codegen.uops import UOpGraph, UOps, PatternMatcher, UOp
+
+class TestPatternMatcher(unittest.TestCase):
+  def test_simple_match(self):
+    matcher = PatternMatcher([({"__name__": "x", "uop": UOps.CONST, "dtype": dtypes.float}, lambda x: x)])
+    c1 = UOp(UOps.CONST, dtypes.float, arg=1.0)
+    c2 = UOp(UOps.CONST, dtypes.int, arg=1)
+    self.assertEqual(matcher.rewrite(c1), c1)
+    self.assertEqual(matcher.rewrite(c2), None)
+
+  def test_vin_one(self):
+    matcher = PatternMatcher([({"__name__": "x", "uop": UOps.ALU, "vin":({"uop": UOps.CONST}, {"uop": UOps.CONST})}, lambda x: x)])
+    c1 = UOp(UOps.CONST, dtypes.float, arg=1.0)
+    c2 = UOp(UOps.CONST, dtypes.float, arg=2.0)
+    c3 = UOp(UOps.ALU, dtypes.float, (c1,c2), BinaryOps.ADD)
+    self.assertEqual(matcher.rewrite(c3), c3)
+    self.assertEqual(matcher.rewrite(c2), None)
+
+  def test_vin_permutations(self):
+    matcher = PatternMatcher([({"__name__": "x", "uop": UOps.ALU, "vin":[{"uop": UOps.CONST}, {"uop": UOps.ALU}]}, lambda x: x)])
+    c1 = UOp(UOps.CONST, dtypes.float, arg=1.0)
+    c2 = UOp(UOps.CONST, dtypes.float, arg=2.0)
+    c3 = UOp(UOps.ALU, dtypes.float, (c1,c2), BinaryOps.ADD)
+    c4 = UOp(UOps.ALU, dtypes.float, (c3,c2), BinaryOps.ADD)
+    c5 = UOp(UOps.ALU, dtypes.float, (c2,c3), BinaryOps.ADD)
+    c6 = UOp(UOps.ALU, dtypes.float, (c3,c4), BinaryOps.ADD)
+    self.assertEqual(matcher.rewrite(c3), None)
+    self.assertEqual(matcher.rewrite(c4), c4)
+    self.assertEqual(matcher.rewrite(c5), c5)
+    self.assertEqual(matcher.rewrite(c6), None)
+
+  def test_vin_repeat(self):
+    matcher = PatternMatcher([({"__name__": "x", "uop": UOps.ALU, "vin":{"uop": UOps.CONST}}, lambda x: x)])
+    c1 = UOp(UOps.CONST, dtypes.float, arg=1.0)
+    c2 = UOp(UOps.CONST, dtypes.float, arg=2.0)
+    c3 = UOp(UOps.ALU, dtypes.float, (c1,c2), BinaryOps.ADD)
+    c4 = UOp(UOps.ALU, dtypes.float, (c2,c3), BinaryOps.ADD)
+    self.assertEqual(matcher.rewrite(c3), c3)
+    self.assertEqual(matcher.rewrite(c4), None)
+
+  def test_rewrite_graph_folds(self):
+    uops = UOpGraph()
+    uops.add(UOps.CONST, dtypes.float, arg=2.0, simplify=False)
+    matcher = PatternMatcher([({"__name__": "x", "uop": UOps.CONST, "dtype": dtypes.float},
+                                lambda x: UOp(UOps.CAST, dtypes.int, (UOp(UOps.ALU, x.dtype, (x,x), BinaryOps.ADD),)))])
+    matcher.rewrite_graph(uops)
+    def _to_key(u): return (u.uop, u.dtype, u.arg)
+    self.assertEqual(_to_key(UOp(UOps.CONST, dtypes.int, arg=4)), _to_key(uops.uops[-1]))
+
+  def test_rewrite_graph_adds(self):
+    uops = UOpGraph()
+    uops.add(UOps.CONST, dtypes.int, arg=2, simplify=False)
+    matcher = PatternMatcher([({"__name__": "x", "uop": UOps.CONST, "dtype": dtypes.int},
+                               lambda x: UOp(UOps.STORE, x.dtype, (UOp(UOps.DEFINE_GLOBAL, x.dtype, tuple(), None), x)))])
+    matcher.rewrite_graph(uops)
+    uops.remove_childless(set(x for x in uops if x.uop in {UOps.STORE}))
+    e1 = UOp(UOps.CONST, dtypes.int, arg=2)
+    e2 = UOp(UOps.DEFINE_GLOBAL, dtypes.int, tuple())
+    e3 = UOp(UOps.STORE, dtypes.int, (e2,e1))
+    def _to_key(u): return (u.uop, u.dtype, u.arg)
+    self.assertEqual(_to_key(e1), _to_key(uops.uops[0]))
+    self.assertEqual(_to_key(e2), _to_key(uops.uops[1]))
+    self.assertEqual(_to_key(e3), _to_key(uops.uops[2]))
+    self.assertEqual(len(uops.uops), 3)
+
+if __name__ == '__main__':
+  unittest.main(verbosity=2)
diff --git a/tinygrad/codegen/uops.py b/tinygrad/codegen/uops.py
index 09156c7a87..6006ad7512 100644
--- a/tinygrad/codegen/uops.py
+++ b/tinygrad/codegen/uops.py
@@ -67,6 +67,27 @@ class PatternMatcher:
       if _match(uop, p, store): return fxn(**store)
     return None
 
+  def rewrite_graph(self, uops: UOpGraph):
+    replace: Dict[UOp, UOp] = {}
+    seen: Set[UOp] = set()
+    for u in uops:
+      if u in seen: continue
+      seen.add(u)
+      for o,n in replace.items():
+        if o in u.vin and u is not n:
+          u.vin = tuple(n if x == o else x for x in u.vin)
+      if rew := self.rewrite(u): replace[u] = rew
+
+    for o,n in replace.items():
+      queue = [n]
+      while queue:
+        if all([qq in uops.uops for qq in queue[-1].vin]):
+          q = queue.pop()
+          new = uops.add(q.uop, q.dtype, q.vin, q.arg, insert_before=max([0]+[uops.uops.index(vv) for vv in q.vin])+1)
+          for vv in uops.uops + queue: vv.vin = tuple(new if x is q else x for x in vv.vin)
+        else: queue.extend([qq for qq in queue[-1].vin if qq not in uops.uops])
+      if not any([o in u.vin for u in uops]): uops.uops.remove(o)
+
 constant_folder = PatternMatcher([
   # const rules
   ({"__name__": "root", "uop": UOps.GEP, "vin": ({"__name__": "c", "uop": UOps.CONST},)}, lambda root, c: UOp.const(root.dtype, c.arg)),
diff --git a/tinygrad/renderer/assembly.py b/tinygrad/renderer/assembly.py
index f7915c3067..e56014e1e4 100644
--- a/tinygrad/renderer/assembly.py
+++ b/tinygrad/renderer/assembly.py
@@ -1,4 +1,4 @@
-from typing import Callable, DefaultDict, Dict, List, Union, NamedTuple, Set
+from typing import Callable, DefaultDict, Dict, List, Union, NamedTuple
 import functools, struct
 from collections import defaultdict
 from tinygrad.codegen.linearizer import UOps, UOp
@@ -76,25 +76,7 @@ def uops_to_asm(lang:AssemblyLanguage, function_name:str, uops:UOpGraph) -> str:
 
   # here we do a pretransform on UOps to fix some shortcomings of PTX
   # all uops must be a register
-  replace: Dict[UOp, UOp] = {}
-  seen: Set[UOp] = set()
-  for u in uops:
-    if u in seen: continue
-    seen.add(u)
-    for o,n in replace.items():
-      if o in u.vin and u is not n:
-        u.vin = tuple(n if x == o else x for x in u.vin)
-    if rew := matcher.rewrite(u): replace[u] = rew
-
-  for o,n in replace.items():
-    queue = [n]
-    while queue:
-      if all([qq in uops.uops for qq in queue[-1].vin]):
-        q = queue.pop()
-        new = uops.add(q.uop, q.dtype, q.vin, q.arg, insert_before=max([uops.uops.index(vv) for vv in q.vin])+1)
-        for vv in uops.uops + queue: vv.vin = tuple(new if x is q else x for x in vv.vin)
-      else: queue.extend([qq for qq in queue[-1].vin if qq not in uops.uops])
-    uops.uops.remove(o)
+  matcher.rewrite_graph(uops)
 
   for pointer_op in list(filter(lambda uop: uop.uop in [UOps.LOAD, UOps.STORE], uops.uops)): ptr_ar(pointer_op, uops)
   uops.remove_childless(set(x for x in uops if x.uop in {UOps.DEFINE_GLOBAL, UOps.PHI, UOps.ENDIF, UOps.ENDLOOP, UOps.STORE}))