static 
void getSyscallArgsFromGuestState ( /*OUT*/SyscallArgs*       canonical,
                                    /*IN*/ VexGuestArchState* gst_vanilla )
{
   VexGuestX86State* gst = (VexGuestX86State*)gst_vanilla;
   UWord *argv = (void *)(UWord)gst->guest_ESP;
   switch (gst->guest_EAX) {
   default:
      canonical->sysno = gst->guest_EAX;
      canonical->indir_sysno = -1;
      break;
   case 198:
      canonical->sysno = argv[1];
      canonical->indir_sysno = 198;
      argv += 2;
      break;
   case 0:
      canonical->sysno = argv[1];
      canonical->indir_sysno = 0;
      argv += 1;
      break;
   }
   canonical->nargs = sysargcount[canonical->sysno];
   memset(&canonical->arg1, 0xfe, (char *)&canonical->indir_sysno - (char *)&canonical->arg1);
   memcpy(&canonical->arg1, &argv[1], canonical->nargs * sizeof(UWord));
}

static 
void putSyscallArgsIntoGuestState ( /*IN*/ SyscallArgs*       canonical,
                                    /*OUT*/VexGuestArchState* gst_vanilla )
{
   VexGuestX86State* gst = (VexGuestX86State*)gst_vanilla;
   UWord *argv = (void *)(UWord)gst->guest_ESP;
   switch (canonical->indir_sysno) {
   case -1:
      gst->guest_EAX = canonical->sysno;
      break;
   case 198:
      gst->guest_EAX = 198;
      argv[1] = 198;
      argv += 2;	/* __syscall(2) has quad aligned args */
      break;
   case 0:
      gst->guest_EAX = 0;
      argv[1] = 0;
      argv += 1;	/* syscall(2) has int aligned args */
      break;
   }
   memcpy(&argv[1], &canonical->arg1, canonical->nargs * sizeof(UWord));
}

static
void getSyscallStatusFromGuestState ( /*OUT*/SyscallStatus*     canonical,
                                      /*IN*/ VexGuestArchState* gst_vanilla )
{
   VexGuestX86State* gst = (VexGuestX86State*)gst_vanilla;
   UInt		     efl = LibVEX_GuestX86_get_eflags( gst );
   canonical->what = (efl & 1)  ? SsFailure  : SsSuccess;
   canonical->val  = (UWord)gst->guest_EAX;
   canonical->val2 = (UWord)gst->guest_EDX;
}

static 
void putSyscallStatusIntoGuestState ( /*IN*/ SyscallStatus*     canonical,
                                      /*OUT*/VexGuestArchState* gst_vanilla )
{
   VexGuestX86State* gst = (VexGuestX86State*)gst_vanilla;
   vg_assert(canonical->what == SsSuccess 
             || canonical->what == SsFailure);
   gst->guest_EAX = canonical->val;
   gst->guest_EDX = canonical->val2;
   if (canonical->what == SsFailure) {
      LibVEX_GuestX86_put_eflag_c( 1, gst );
   } else {
      LibVEX_GuestX86_put_eflag_c( 0, gst );
   }
}