diff --git a/tinygrad/uop/symbolic.py b/tinygrad/uop/symbolic.py
index 9ec4aa8989..f676b9e123 100644
--- a/tinygrad/uop/symbolic.py
+++ b/tinygrad/uop/symbolic.py
@@ -102,13 +102,11 @@ symbolic_simple = propagate_invalid + PatternMatcher([
   # positive const ** x
   (UPat.cvar("c", vec=False).alu(Ops.POW, UPat.var("x")), lambda c,x: c if c.arg == 1 else (x*math.log2(c.arg)).exp2() if c.arg > 0 else None),
   # rules for threefry
-  ((UPat.var('x', dtypes.uint64)&0xFFFFFFFF).cast(dtypes.uint32), lambda x: x.cast(dtypes.uint32)&0xFFFFFFFF), # TODO: why is the and needed?
+  ((UPat.var('x', dtypes.uint64)&0xFFFFFFFF).cast(dtypes.uint32), lambda x: x.cast(dtypes.uint32)),
   (((UPat.var(None, dtypes.uint64)*(1<<32)) | UPat.var('y',  dtypes.uint32).cast(dtypes.uint64)).cast(dtypes.uint32), lambda y: y),
   (((UPat.var('x',  dtypes.uint64)*(1<<32)) | UPat.var(None, dtypes.uint32).cast(dtypes.uint64))//(1<<32), lambda x: x),
-  # new decomp rules for threefry
   (((UPat.var(None, dtypes.uint64)<<32) | UPat.var('y',  dtypes.uint32).cast(dtypes.uint64)).cast(dtypes.uint32), lambda y: y),
   (((UPat.var('x',  dtypes.uint64)<<32) | UPat.var(None, dtypes.uint32).cast(dtypes.uint64))>>32, lambda x: x),
-  (UPat.var('b').where(UPat.var('x', dtypes.uint32).cast(dtypes.uint64), UPat.const(dtypes.uint64, 0)).cast(dtypes.uint32), lambda b,x: b.where(x,0)),
   # ** simple where folding **
   # a conditional with the same results either way is a noop, also fold const conditionals
   (UPat.var().where(UPat.var("val"), UPat.var("val")), lambda val: val),