add a gate to rewrite if there's no rules [pr]

tinygrad/uop/ops.py

@@ -1034,10 +1034,11 @@ class PatternMatcher:
   def __add__(self, more:PatternMatcher) -> PatternMatcher: return PatternMatcher(self.patterns+more.patterns)
 
   def rewrite(self, uop:UOp, ctx=None) -> UOp|None:
-    ler = {u.op for u in uop.src}
-    for _,match,early_reject in self.pdict.get(uop.op, []):
-      if not early_reject.issubset(ler): continue
-      if (ret:=match(uop, ctx)) is not None and ret is not uop: return ret
+    if len(pats:=self.pdict.get(uop.op, [])):
+      ler = {u.op for u in uop.src}
+      for _,match,early_reject in pats:
+        if not early_reject.issubset(ler): continue
+        if (ret:=match(uop, ctx)) is not None and ret is not uop: return ret
     return None
 
 # *** tracking pattern matcher ***
@@ -1119,28 +1120,29 @@ def profile_matches(fxn:Callable):
 
 class TrackedPatternMatcher(PatternMatcher):
   def rewrite(self, uop:UOp, ctx=None) -> UOp|None:
-    ret = None
-    ler = {u.op for u in uop.src}
-    for p,match,early_reject in self.pdict.get(uop.op, []):
-      if p not in match_stats: match_stats[p] = [0,0,0.0,0.0]
-      st = time.perf_counter()
-      if not early_reject.issubset(ler):
+    if len(pats:=self.pdict.get(uop.op, [])):
+      ret = None
+      ler = {u.op for u in uop.src}
+      for p,match,early_reject in pats:
+        if p not in match_stats: match_stats[p] = [0,0,0.0,0.0]
+        st = time.perf_counter()
+        if not early_reject.issubset(ler):
+          match_stats[p][2] += time.perf_counter()-st
+          continue
+        match_stats[p][1] += 1
+        try: ret = match(uop, ctx)
+        except Exception:
+          if TRACK_MATCH_STATS >= 2 and active_rewrites:
+            active_rewrites[-1].matches.append((uop.trace_num, UOp(Ops.REWRITE_ERROR,src=uop.src,arg=str(sys.exc_info()[1])).trace_num,p.location,0))
+          raise
+        if ret is not None and ret is not uop:
+          match_stats[p][0] += 1
+          match_stats[p][3] += (et:=time.perf_counter()-st)
+          if TRACK_MATCH_STATS >= 3: print(f"{et*1e6:7.2f} us -- ", printable(p.location))
+          if TRACK_MATCH_STATS >= 2 and isinstance(ret, UOp) and active_rewrites:
+            active_rewrites[-1].matches.append((uop.trace_num, ret.trace_num, p.location, et))
+          return ret
         match_stats[p][2] += time.perf_counter()-st
-        continue
-      match_stats[p][1] += 1
-      try: ret = match(uop, ctx)
-      except Exception:
-        if TRACK_MATCH_STATS >= 2 and active_rewrites:
-          active_rewrites[-1].matches.append((uop.trace_num, UOp(Ops.REWRITE_ERROR,src=uop.src,arg=str(sys.exc_info()[1])).trace_num,p.location,0))
-        raise
-      if ret is not None and ret is not uop:
-        match_stats[p][0] += 1
-        match_stats[p][3] += (et:=time.perf_counter()-st)
-        if TRACK_MATCH_STATS >= 3: print(f"{et*1e6:7.2f} us -- ", printable(p.location))
-        if TRACK_MATCH_STATS >= 2 and isinstance(ret, UOp) and active_rewrites:
-          active_rewrites[-1].matches.append((uop.trace_num, ret.trace_num, p.location, et))
-        return ret
-      match_stats[p][2] += time.perf_counter()-st
     return None
 
 @dataclass(frozen=True)