https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107815
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ppalka at gcc dot gnu.org,
| |redi at gcc dot gnu.org
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
You're right.
This is the:
else if (fmt == chars_format::fixed && fd.exponent >= 0)
{
// The Ryu exponent is positive, and so this number's shortest
// representation is a whole number, to be formatted in fixed instead
// of scientific notation "as if by std::printf". This means we may
// need to print more digits of the IEEE mantissa than what the
// shortest scientific form given by Ryu provides.
//
// For instance, the exactly representable number
// 12300000000000001048576.0 has as its shortest scientific
// representation 123e+22, so in this case fd.mantissa is 123 and
// fd.exponent is 22, which doesn't have enough information to format
// the number exactly. So we defer to Ryu's d2fixed_buffered_n with
// precision=0 to format the number in the general case here.
case for which ryu doesn't handle d2fixed_buffered_n for wider than double and
so use
const int output_length = sprintf_ld(buffer,
expected_output_length + 1,
"%.0Lf", value);
and Solaris apparently violates ISO C99 in producing for the last 3 printf
calls scientifix values rather than fixed:
#include <stdio.h>
int
main ()
{
printf ("%.0f\n", __DBL_MAX__);
printf ("%.0Lf\n", (long double) __DBL_MAX__);
printf ("%.0Lf\n", 2.0L * __DBL_MAX__);
printf ("%.0Lf\n", 1e+202L * __DBL_MAX__);
printf ("%.0Lf\n", 1e+203L * __DBL_MAX__);
printf ("%.0Lf\n", (long double) __DBL_MAX__ * (long double) __DBL_MAX__);
printf ("%.0Lf\n", __LDBL_MAX__);
}
The 1e+202L * __DBL_MAX__ number is:
1797693134862315708145274237317043363780293901488132670510305396153274401107450252964067353821542098883610426262810674725334159395885309388675990127492090757713383689567223448511120723139743573688679064280172265585993927318314820133831157520860190820700571151387146478495139447053313076754655788391539857757373041885363113533243178943928496535556954517148959372706003524689906194839868952331046086040494963209033312113173876118835007579814542996644987978064090838995977878567921521624960885877081515358704107520
which is 511 bytes long excluding '\0' terminator, so bet they have somewhere
fixed length temporary buffer or what.
Jonathan, shall we just #ifdef out the
std::numeric_limits<std::float128_t>::max()
test in that test for Solaris and maybe HP-UX if it suffers from the same bug?
