case 's': if (arg) return 0;  break;
md_parse_option (c, arg)     int c;     char *arg;{  switch (c)    {    case 'u':      /* -u means that any undefined symbols should be treated as	 external, which is the default for gas anyhow.  */      break;    case 'm':      /* -mpwrx and -mpwr2 mean to assemble for the IBM POWER/2         (RIOS2).  */      if (strcmp (arg, "pwrx") == 0 || strcmp (arg, "pwr2") == 0)	ppc_cpu = PPC_OPCODE_POWER | PPC_OPCODE_POWER2;      /* -mpwr means to assemble for the IBM POWER (RIOS1).  */      else if (strcmp (arg, "pwr") == 0)	ppc_cpu = PPC_OPCODE_POWER;      /* -m601 means to assemble for the Motorola PowerPC 601, which includes         instructions that are holdovers from the Power. */      else if (strcmp (arg, "601") == 0)	ppc_cpu = PPC_OPCODE_PPC | PPC_OPCODE_601;      /* -mppc, -mppc32, -m603, and -m604 mean to assemble for the         Motorola PowerPC 603/604.  */      else if (strcmp (arg, "ppc") == 0	       || strcmp (arg, "ppc32") == 0	       || strcmp (arg, "403") == 0	       || strcmp (arg, "603") == 0	       || strcmp (arg, "604") == 0)	ppc_cpu = PPC_OPCODE_PPC;      /* -mppc64 and -m620 mean to assemble for the 64-bit PowerPC         620.  */      else if (strcmp (arg, "ppc64") == 0 || strcmp (arg, "620") == 0)	{	  ppc_cpu = PPC_OPCODE_PPC;	  ppc_size = PPC_OPCODE_64;	}      /* -mcom means assemble for the common intersection between Power	 and PowerPC.  At present, we just allow the union, rather	 than the intersection.  */      else if (strcmp (arg, "com") == 0)	ppc_cpu = PPC_OPCODE_COMMON;      /* -many means to assemble for any architecture (PWR/PWRX/PPC).  */      else if (strcmp (arg, "any") == 0)	ppc_cpu = PPC_OPCODE_ANY;#ifdef OBJ_ELF      /* -mrelocatable/-mrelocatable-lib -- warn about initializations that require relocation */      else if (strcmp (arg, "relocatable") == 0)	{	  mrelocatable = true;	  ppc_flags |= EF_PPC_RELOCATABLE;	}      else if (strcmp (arg, "relocatable-lib") == 0)	{	  mrelocatable = true;	  ppc_flags |= EF_PPC_RELOCATABLE_LIB;	}      /* -memb, set embedded bit */      else if (strcmp (arg, "emb") == 0)	ppc_flags |= EF_PPC_EMB;      /* -mlittle/-mbig set the endianess */      else if (strcmp (arg, "little") == 0 || strcmp (arg, "little-endian") == 0)	{	  target_big_endian = 0;	  set_target_endian = 1;	}      else if (strcmp (arg, "big") == 0 || strcmp (arg, "big-endian") == 0)	{	  target_big_endian = 1;	  set_target_endian = 1;	}#endif      else	{	  as_bad ("invalid switch -m%s", arg);	  return 0;	}      break;#ifdef OBJ_ELF      /* -V: SVR4 argument to print version ID.  */    case 'V':      print_version_id ();      break;      /* -Qy, -Qn: SVR4 arguments controlling whether a .comment section	 should be emitted or not.  FIXME: Not implemented.  */    case 'Q':      break;#endif    default:      return 0;    }  return 1;}