simpler reduce that just removes ones

tinygrad/uop/ops.py

@@ -257,18 +257,12 @@ class UOp(MathTrait, metaclass=UOpMetaClass):
   @staticmethod
   def range(dtype:DType, end:sint, idx:int): return UOp(Ops.RANGE, dtype=dtype, src=(sint_to_uop(end),), arg=idx)
   def r(self, op:Ops, axis:tuple[int, ...], permute=True):
+    assert permute
     axis = tuple(sorted([x for x in axis if resolve(self.shape[x] != 1)]))
     if len(axis) == 0: return self
-    # move any non reduce axis before the first reduce axis
-    move_early, rest = partition(range(axis[0], len(self.shape)), lambda i: i not in axis and resolve(self.shape[i] != 1))
-    if move_early and permute:
-      permaxis = tuple(range(axis[0])) + tuple(move_early) + tuple(rest)
-      ret = self.permute(permaxis)
-      new_axis = tuple([x for x in range(axis[0]+len(move_early), len(self.shape)) if resolve(ret.shape[x] != 1)])
-      assert len(axis) == len(new_axis)
-    else:
-      ret, new_axis = self, axis
-    ret = UOp(Ops.REDUCE_AXIS, self.dtype, (ret,), (op, new_axis))
+    ret = self.permute(tuple([i for i in range(len(self.shape)) if i not in axis])+axis)
+    ret = ret.reshape(tuple([s for s in ret.shape if resolve(s != 1)]))
+    ret = UOp(Ops.REDUCE_AXIS, self.dtype, (ret,), (op, tuple(range(len(ret.shape)-len(axis), len(ret.shape)))))
     return ret.reshape(tuple([x if i not in axis else 1 for i,x in enumerate(self.shape)]))
   def reduce(self, *src:UOp, **kwargs): return UOp(Ops.REDUCE, kwargs.pop('dtype', self.dtype), src=(self,)+src, **kwargs)
   def contiguous(self): return self.alu(Ops.CONTIGUOUS)