[Bug middle-end/63793] -mcmodel=medium in gfortran on x86_64 emits references that are RIP relative (instead of using the GOT)

[howarth at bromo dot med.uc.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63793

--- Comment #18 from howarth at bromo dot med.uc.edu ---
Another interesting section of code in gcc/config/i386/i386.c

  else
    {
      /* For TARGET_64BIT and MS_ABI, force pic on, in order to enable the
         use of rip-relative addressing.  This eliminates fixups that
         would otherwise be needed if this object is to be placed in a
         DLL, and is essentially just as efficient as direct addressing.  */
      if (TARGET_64BIT_P (opts->x_ix86_isa_flags)
          && (TARGET_RDOS || TARGET_PECOFF))
        opts->x_ix86_cmodel = CM_MEDIUM_PIC, opts->x_flag_pic = 1;
      else if (TARGET_64BIT_P (opts->x_ix86_isa_flags))
        opts->x_ix86_cmodel = opts->x_flag_pic ? CM_SMALL_PIC : CM_SMALL;
      else
        opts->x_ix86_cmodel = CM_32;
    }