[Bug middle-end/79536] [5/6/7 Regression] ICE in fold_binary_loc, at fold-const.c:9060

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79536

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Marek Polacek from comment #4)
> So perhaps this:
> --- a/gcc/fold-const.c
> +++ b/gcc/fold-const.c
> @@ -581,8 +581,8 @@ fold_negate_expr (location_t loc, tree t)
>      case COMPLEX_EXPR:
>        if (negate_expr_p (t))
>     return fold_build2_loc (loc, COMPLEX_EXPR, type,
> -               fold_negate_expr (loc, TREE_OPERAND (t, 0)),
> -               fold_negate_expr (loc, TREE_OPERAND (t, 1)));
> +               negate_expr (TREE_OPERAND (t, 0)),
> +               negate_expr (TREE_OPERAND (t, 1)));
>        break;
>  
>      case CONJ_EXPR:
> 
> 
> (and I guess handle CONJ_EXPR the same)

Why?  negate_expr_p checks

    case COMPLEX_EXPR:
      return negate_expr_p (TREE_OPERAND (t, 0))
             && negate_expr_p (TREE_OPERAND (t, 1));

so it is negatable.