no load substitute in uop_given_valid [pr] (#13333)

tinygrad/uop/symbolic.py

@@ -407,14 +407,10 @@ def uop_given_valid(valid:UOp, uop:UOp, try_simplex=True) -> UOp:
     expr, is_upper, c = res
     bounds[expr][int(is_upper)] = c
 
-  # don't simplify any other gates, can lead to OOB, we substitute them back later
-  uop = uop.substitute((load_subs:={u: UOp(Ops.NOOP, dtype=u.dtype, arg=u) for u in uop.toposort() if u.op is Ops.INDEX}))
-
   # simplify uop given that valid is True
   all_candidates = []
   for i,(expr,v) in enumerate(bounds.items()):
     v0, v1 = (expr.vmin if v[0] is None else v[0], expr.vmax if v[1] is None else v[1])
-    expr = expr.substitute(load_subs)  # make sure expr appears in same form in the uop
     # try checking the whole clause
     all_candidates.append((expr, UOp.variable(f"fake{i}", v0, v1, expr.dtype)))
 
@@ -438,8 +434,6 @@ def uop_given_valid(valid:UOp, uop:UOp, try_simplex=True) -> UOp:
   # try all the valids together (but only the whole expressions)
   if (s_uop:=uop.substitute(sub_dict:=dict(all_candidates))) is not uop:
     uop = s_uop.simplify().substitute({newX:X for X,newX in sub_dict.items()}).simplify(full_symbolic=False)
-  # put the loads back in
-  uop = uop.substitute({v:k for k,v in load_subs.items()})
   return uop
 
 def _valid_priority(v: UOp, valids:list[UOp]):