PNG_FP_IS_ZERO    166 contrib/libtests/tarith.c          assert(!PNG_FP_IS_ZERO(state));
PNG_FP_IS_ZERO    169 contrib/libtests/tarith.c       else if (PNG_FP_IS_ZERO(state) && !(test == 0))
PNG_FP_IS_ZERO    183 contrib/libtests/tarith.c          assert(!PNG_FP_IS_ZERO(state));
PNG_FP_IS_ZERO    389 contrib/libtests/tarith.c    if (PNG_FP_IS_ZERO(c.state) != (number_is_valid && c.is_zero))