Default libm mode is XOPEN?

[Kyrill Tkachov <kyrylo dot tkachov at arm dot com>]

Hi all,

Looking at newlib/libm/common/fdlibm.h I see the lines:

/* REDHAT LOCAL: Default to XOPEN_MODE.  */
#define _XOPEN_MODE

Building an aarch64-none-elf compiler with newlib, the following test 
program:
#include <stdio.h>
#include <math.h>

int
main (void)
{
  printf ("_LIB_VERSION: %d\n", _LIB_VERSION);
  printf ("_XOPEN_: %d\n", _XOPEN_);
  return 0;
}

produces:
_LIB_VERSION: 1
_XOPEN_: 1


Is this /* REDHAT LOCAL: Default to XOPEN_MODE.  */ really intentional 
for all users of newlib?
I thought IEEE was supposed to be the default one. Or are targets 
expected to override this?

Thanks,
Kyrill