[Bug tree-optimization/103194] [12 Regression] ice in optimize_atomic_bit_test_and with __sync_fetch_and_and since r12-5102-gfb161782545224f5

["crazylht at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103194

--- Comment #10 from Hongtao.liu <crazylht at gmail dot com> ---
(In reply to Hongtao.liu from comment #9)
> (In reply to H.J. Lu from comment #6)
> > Created attachment 51785 [details]
> > The v2 incomplete patch
> > 
> > Hongtao, please finish it.  Thanks.
> 
> I'm trying to handle narrowing part in match.pd and add else return; when
> precision is not equal.
> 
> (for bit_op (bit_and bit_xor bit_ior)
>  (simplify
>   (bit_op (convert@0 @1) (convert@2 @3))
>   (if (INTEGRAL_TYPE_P (type)
>       && INTEGRAL_TYPE_P (TREE_TYPE (@1))
>       && tree_nop_conversion_p (TREE_TYPE (@1), TREE_TYPE (@3))
>       && single_use (@0)
>       && single_use (@2)
>       && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@1)))
>    (with { tree type1 = TREE_TYPE (@1); }
>     (convert (bit_op @1 (convert:type1 @3)))))))
> 
> (for bit_op (bit_and bit_xor bit_ior)
>  (simplify
>   (bit_op (convert@0 @1) INTEGER_CST@2)
>   (if (INTEGRAL_TYPE_P (type)
>       && INTEGRAL_TYPE_P (TREE_TYPE (@1))
>       && single_use (@0)
>       && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@1)))
>    (convert (bit_op @1 { fold_convert (TREE_TYPE (@1), @2); })))))

hmm, cause infinite loop because of

      /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
         constants (if x has signed type, the sign bit cannot be set
         in c).  This folds extension into the BIT_AND_EXPR.
         ??? We don't do it for BOOLEAN_TYPE or ENUMERAL_TYPE because they
         very likely don't have maximal range for their precision and this
         transformation effectively doesn't preserve non-maximal ranges.  */
      if (TREE_CODE (type) == INTEGER_TYPE
          && TREE_CODE (op0) == BIT_AND_EXPR
          && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)