https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113797
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- static integer(kind=8) slen.1; inside void check (integer(kind=4) & restrict i) pstr.2 = 0B; slen.1 = 0; concat_f (&pstr.2, &slen.1, &"0123456 "[1]{lb: 1 sz: 1}, D.4331, 8); That is it used for the return value of concat_f. I don't know why it is static but that is almost likely the cause of the issue there.