1. Nick Coghlan
  2. cpython_sandbox

Source

cpython_sandbox / Modules / _ctypes / libffi / src / s390 / ffi.c

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
/* -----------------------------------------------------------------------
   ffi.c - Copyright (c) 2000, 2007 Software AG
           Copyright (c) 2008 Red Hat, Inc
 
   S390 Foreign Function Interface
 
   Permission is hereby granted, free of charge, to any person obtaining
   a copy of this software and associated documentation files (the
   ``Software''), to deal in the Software without restriction, including
   without limitation the rights to use, copy, modify, merge, publish,
   distribute, sublicense, and/or sell copies of the Software, and to
   permit persons to whom the Software is furnished to do so, subject to
   the following conditions:
 
   The above copyright notice and this permission notice shall be included
   in all copies or substantial portions of the Software.
 
   THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR
   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   OTHER DEALINGS IN THE SOFTWARE.
   ----------------------------------------------------------------------- */
/*====================================================================*/
/*                          Includes                                  */
/*                          --------                                  */
/*====================================================================*/
 
#include <ffi.h>
#include <ffi_common.h>
 
#include <stdlib.h>
#include <stdio.h>
 
/*====================== End of Includes =============================*/
 
/*====================================================================*/
/*                           Defines                                  */
/*                           -------                                  */
/*====================================================================*/

/* Maximum number of GPRs available for argument passing.  */ 
#define MAX_GPRARGS 5

/* Maximum number of FPRs available for argument passing.  */ 
#ifdef __s390x__
#define MAX_FPRARGS 4
#else
#define MAX_FPRARGS 2
#endif

/* Round to multiple of 16.  */
#define ROUND_SIZE(size) (((size) + 15) & ~15)

/* If these values change, sysv.S must be adapted!  */
#define FFI390_RET_VOID		0
#define FFI390_RET_STRUCT	1
#define FFI390_RET_FLOAT	2
#define FFI390_RET_DOUBLE	3
#define FFI390_RET_INT32	4
#define FFI390_RET_INT64	5

/*===================== End of Defines ===============================*/
 
/*====================================================================*/
/*                          Prototypes                                */
/*                          ----------                                */
/*====================================================================*/
 
static void ffi_prep_args (unsigned char *, extended_cif *);
void
#if __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ > 2)
__attribute__ ((visibility ("hidden")))
#endif
ffi_closure_helper_SYSV (ffi_closure *, unsigned long *, 
			 unsigned long long *, unsigned long *);

/*====================== End of Prototypes ===========================*/
 
/*====================================================================*/
/*                          Externals                                 */
/*                          ---------                                 */
/*====================================================================*/
 
extern void ffi_call_SYSV(unsigned,
			  extended_cif *,
			  void (*)(unsigned char *, extended_cif *),
			  unsigned,
			  void *,
			  void (*fn)(void));

extern void ffi_closure_SYSV(void);
 
/*====================== End of Externals ============================*/
 
/*====================================================================*/
/*                                                                    */
/* Name     - ffi_check_struct_type.                                  */
/*                                                                    */
/* Function - Determine if a structure can be passed within a         */
/*            general purpose or floating point register.             */
/*                                                                    */
/*====================================================================*/
 
static int
ffi_check_struct_type (ffi_type *arg)
{
  size_t size = arg->size;

  /* If the struct has just one element, look at that element
     to find out whether to consider the struct as floating point.  */
  while (arg->type == FFI_TYPE_STRUCT 
         && arg->elements[0] && !arg->elements[1])
    arg = arg->elements[0];

  /* Structs of size 1, 2, 4, and 8 are passed in registers,
     just like the corresponding int/float types.  */
  switch (size)
    {
      case 1:
        return FFI_TYPE_UINT8;

      case 2:
        return FFI_TYPE_UINT16;

      case 4:
	if (arg->type == FFI_TYPE_FLOAT)
          return FFI_TYPE_FLOAT;
	else
	  return FFI_TYPE_UINT32;

      case 8:
	if (arg->type == FFI_TYPE_DOUBLE)
          return FFI_TYPE_DOUBLE;
	else
	  return FFI_TYPE_UINT64;

      default:
	break;
    }

  /* Other structs are passed via a pointer to the data.  */
  return FFI_TYPE_POINTER;
}
 
/*======================== End of Routine ============================*/
 
/*====================================================================*/
/*                                                                    */
/* Name     - ffi_prep_args.                                          */
/*                                                                    */
/* Function - Prepare parameters for call to function.                */
/*                                                                    */
/* ffi_prep_args is called by the assembly routine once stack space   */
/* has been allocated for the function's arguments.                   */
/*                                                                    */
/*====================================================================*/
 
static void
ffi_prep_args (unsigned char *stack, extended_cif *ecif)
{
  /* The stack space will be filled with those areas:

	FPR argument register save area     (highest addresses)
	GPR argument register save area
	temporary struct copies
	overflow argument area              (lowest addresses)

     We set up the following pointers:

        p_fpr: bottom of the FPR area (growing upwards)
	p_gpr: bottom of the GPR area (growing upwards)
	p_ov: bottom of the overflow area (growing upwards)
	p_struct: top of the struct copy area (growing downwards)

     All areas are kept aligned to twice the word size.  */

  int gpr_off = ecif->cif->bytes;
  int fpr_off = gpr_off + ROUND_SIZE (MAX_GPRARGS * sizeof (long));

  unsigned long long *p_fpr = (unsigned long long *)(stack + fpr_off);
  unsigned long *p_gpr = (unsigned long *)(stack + gpr_off);
  unsigned char *p_struct = (unsigned char *)p_gpr;
  unsigned long *p_ov = (unsigned long *)stack;

  int n_fpr = 0;
  int n_gpr = 0;
  int n_ov = 0;

  ffi_type **ptr;
  void **p_argv = ecif->avalue;
  int i;
 
  /* If we returning a structure then we set the first parameter register
     to the address of where we are returning this structure.  */

  if (ecif->cif->flags == FFI390_RET_STRUCT)
    p_gpr[n_gpr++] = (unsigned long) ecif->rvalue;

  /* Now for the arguments.  */
 
  for (ptr = ecif->cif->arg_types, i = ecif->cif->nargs;
       i > 0;
       i--, ptr++, p_argv++)
    {
      void *arg = *p_argv;
      int type = (*ptr)->type;

#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
      /* 16-byte long double is passed like a struct.  */
      if (type == FFI_TYPE_LONGDOUBLE)
	type = FFI_TYPE_STRUCT;
#endif

      /* Check how a structure type is passed.  */
      if (type == FFI_TYPE_STRUCT)
	{
	  type = ffi_check_struct_type (*ptr);

	  /* If we pass the struct via pointer, copy the data.  */
	  if (type == FFI_TYPE_POINTER)
	    {
	      p_struct -= ROUND_SIZE ((*ptr)->size);
	      memcpy (p_struct, (char *)arg, (*ptr)->size);
	      arg = &p_struct;
	    }
	}

      /* Now handle all primitive int/pointer/float data types.  */
      switch (type) 
	{
	  case FFI_TYPE_DOUBLE:
	    if (n_fpr < MAX_FPRARGS)
	      p_fpr[n_fpr++] = *(unsigned long long *) arg;
	    else
#ifdef __s390x__
	      p_ov[n_ov++] = *(unsigned long *) arg;
#else
	      p_ov[n_ov++] = ((unsigned long *) arg)[0],
	      p_ov[n_ov++] = ((unsigned long *) arg)[1];
#endif
	    break;
	
	  case FFI_TYPE_FLOAT:
	    if (n_fpr < MAX_FPRARGS)
	      p_fpr[n_fpr++] = (long long) *(unsigned int *) arg << 32;
	    else
	      p_ov[n_ov++] = *(unsigned int *) arg;
	    break;

	  case FFI_TYPE_POINTER:
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = (unsigned long)*(unsigned char **) arg;
	    else
	      p_ov[n_ov++] = (unsigned long)*(unsigned char **) arg;
	    break;
 
	  case FFI_TYPE_UINT64:
	  case FFI_TYPE_SINT64:
#ifdef __s390x__
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = *(unsigned long *) arg;
	    else
	      p_ov[n_ov++] = *(unsigned long *) arg;
#else
	    if (n_gpr == MAX_GPRARGS-1)
	      n_gpr = MAX_GPRARGS;
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = ((unsigned long *) arg)[0],
	      p_gpr[n_gpr++] = ((unsigned long *) arg)[1];
	    else
	      p_ov[n_ov++] = ((unsigned long *) arg)[0],
	      p_ov[n_ov++] = ((unsigned long *) arg)[1];
#endif
	    break;
 
	  case FFI_TYPE_UINT32:
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = *(unsigned int *) arg;
	    else
	      p_ov[n_ov++] = *(unsigned int *) arg;
	    break;
 
	  case FFI_TYPE_INT:
	  case FFI_TYPE_SINT32:
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = *(signed int *) arg;
	    else
	      p_ov[n_ov++] = *(signed int *) arg;
	    break;
 
	  case FFI_TYPE_UINT16:
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = *(unsigned short *) arg;
	    else
	      p_ov[n_ov++] = *(unsigned short *) arg;
	    break;
 
	  case FFI_TYPE_SINT16:
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = *(signed short *) arg;
	    else
	      p_ov[n_ov++] = *(signed short *) arg;
	    break;

	  case FFI_TYPE_UINT8:
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = *(unsigned char *) arg;
	    else
	      p_ov[n_ov++] = *(unsigned char *) arg;
	    break;
 
	  case FFI_TYPE_SINT8:
	    if (n_gpr < MAX_GPRARGS)
	      p_gpr[n_gpr++] = *(signed char *) arg;
	    else
	      p_ov[n_ov++] = *(signed char *) arg;
	    break;
 
	  default:
	    FFI_ASSERT (0);
	    break;
        }
    }
}

/*======================== End of Routine ============================*/
 
/*====================================================================*/
/*                                                                    */
/* Name     - ffi_prep_cif_machdep.                                   */
/*                                                                    */
/* Function - Perform machine dependent CIF processing.               */
/*                                                                    */
/*====================================================================*/
 
ffi_status
ffi_prep_cif_machdep(ffi_cif *cif)
{
  size_t struct_size = 0;
  int n_gpr = 0;
  int n_fpr = 0;
  int n_ov = 0;

  ffi_type **ptr;
  int i;

  /* Determine return value handling.  */ 

  switch (cif->rtype->type)
    {
      /* Void is easy.  */
      case FFI_TYPE_VOID:
	cif->flags = FFI390_RET_VOID;
	break;

      /* Structures are returned via a hidden pointer.  */
      case FFI_TYPE_STRUCT:
	cif->flags = FFI390_RET_STRUCT;
	n_gpr++;  /* We need one GPR to pass the pointer.  */
	break; 

      /* Floating point values are returned in fpr 0.  */
      case FFI_TYPE_FLOAT:
	cif->flags = FFI390_RET_FLOAT;
	break;

      case FFI_TYPE_DOUBLE:
	cif->flags = FFI390_RET_DOUBLE;
	break;

#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
      case FFI_TYPE_LONGDOUBLE:
	cif->flags = FFI390_RET_STRUCT;
	n_gpr++;
	break;
#endif
      /* Integer values are returned in gpr 2 (and gpr 3
	 for 64-bit values on 31-bit machines).  */
      case FFI_TYPE_UINT64:
      case FFI_TYPE_SINT64:
	cif->flags = FFI390_RET_INT64;
	break;

      case FFI_TYPE_POINTER:
      case FFI_TYPE_INT:
      case FFI_TYPE_UINT32:
      case FFI_TYPE_SINT32:
      case FFI_TYPE_UINT16:
      case FFI_TYPE_SINT16:
      case FFI_TYPE_UINT8:
      case FFI_TYPE_SINT8:
	/* These are to be extended to word size.  */
#ifdef __s390x__
	cif->flags = FFI390_RET_INT64;
#else
	cif->flags = FFI390_RET_INT32;
#endif
	break;
 
      default:
        FFI_ASSERT (0);
        break;
    }

  /* Now for the arguments.  */
 
  for (ptr = cif->arg_types, i = cif->nargs;
       i > 0;
       i--, ptr++)
    {
      int type = (*ptr)->type;

#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
      /* 16-byte long double is passed like a struct.  */
      if (type == FFI_TYPE_LONGDOUBLE)
	type = FFI_TYPE_STRUCT;
#endif

      /* Check how a structure type is passed.  */
      if (type == FFI_TYPE_STRUCT)
	{
	  type = ffi_check_struct_type (*ptr);

	  /* If we pass the struct via pointer, we must reserve space
	     to copy its data for proper call-by-value semantics.  */
	  if (type == FFI_TYPE_POINTER)
	    struct_size += ROUND_SIZE ((*ptr)->size);
	}

      /* Now handle all primitive int/float data types.  */
      switch (type) 
	{
	  /* The first MAX_FPRARGS floating point arguments
	     go in FPRs, the rest overflow to the stack.  */

	  case FFI_TYPE_DOUBLE:
	    if (n_fpr < MAX_FPRARGS)
	      n_fpr++;
	    else
	      n_ov += sizeof (double) / sizeof (long);
	    break;
	
	  case FFI_TYPE_FLOAT:
	    if (n_fpr < MAX_FPRARGS)
	      n_fpr++;
	    else
	      n_ov++;
	    break;

	  /* On 31-bit machines, 64-bit integers are passed in GPR pairs,
	     if one is still available, or else on the stack.  If only one
	     register is free, skip the register (it won't be used for any 
	     subsequent argument either).  */
	      
#ifndef __s390x__
	  case FFI_TYPE_UINT64:
	  case FFI_TYPE_SINT64:
	    if (n_gpr == MAX_GPRARGS-1)
	      n_gpr = MAX_GPRARGS;
	    if (n_gpr < MAX_GPRARGS)
	      n_gpr += 2;
	    else
	      n_ov += 2;
	    break;
#endif

	  /* Everything else is passed in GPRs (until MAX_GPRARGS
	     have been used) or overflows to the stack.  */

	  default: 
	    if (n_gpr < MAX_GPRARGS)
	      n_gpr++;
	    else
	      n_ov++;
	    break;
        }
    }

  /* Total stack space as required for overflow arguments
     and temporary structure copies.  */

  cif->bytes = ROUND_SIZE (n_ov * sizeof (long)) + struct_size;
 
  return FFI_OK;
}
 
/*======================== End of Routine ============================*/
 
/*====================================================================*/
/*                                                                    */
/* Name     - ffi_call.                                               */
/*                                                                    */
/* Function - Call the FFI routine.                                   */
/*                                                                    */
/*====================================================================*/
 
void
ffi_call(ffi_cif *cif,
	 void (*fn)(void),
	 void *rvalue,
	 void **avalue)
{
  int ret_type = cif->flags;
  extended_cif ecif;
 
  ecif.cif    = cif;
  ecif.avalue = avalue;
  ecif.rvalue = rvalue;

  /* If we don't have a return value, we need to fake one.  */
  if (rvalue == NULL)
    {
      if (ret_type == FFI390_RET_STRUCT)
	ecif.rvalue = alloca (cif->rtype->size);
      else
	ret_type = FFI390_RET_VOID;
    } 

  switch (cif->abi)
    {
      case FFI_SYSV:
        ffi_call_SYSV (cif->bytes, &ecif, ffi_prep_args,
		       ret_type, ecif.rvalue, fn);
        break;
 
      default:
        FFI_ASSERT (0);
        break;
    }
}
 
/*======================== End of Routine ============================*/

/*====================================================================*/
/*                                                                    */
/* Name     - ffi_closure_helper_SYSV.                                */
/*                                                                    */
/* Function - Call a FFI closure target function.                     */
/*                                                                    */
/*====================================================================*/
 
void
ffi_closure_helper_SYSV (ffi_closure *closure,
			 unsigned long *p_gpr,
			 unsigned long long *p_fpr,
			 unsigned long *p_ov)
{
  unsigned long long ret_buffer;

  void *rvalue = &ret_buffer;
  void **avalue;
  void **p_arg;

  int n_gpr = 0;
  int n_fpr = 0;
  int n_ov = 0;

  ffi_type **ptr;
  int i;

  /* Allocate buffer for argument list pointers.  */

  p_arg = avalue = alloca (closure->cif->nargs * sizeof (void *));

  /* If we returning a structure, pass the structure address 
     directly to the target function.  Otherwise, have the target 
     function store the return value to the GPR save area.  */

  if (closure->cif->flags == FFI390_RET_STRUCT)
    rvalue = (void *) p_gpr[n_gpr++];

  /* Now for the arguments.  */

  for (ptr = closure->cif->arg_types, i = closure->cif->nargs;
       i > 0;
       i--, p_arg++, ptr++)
    {
      int deref_struct_pointer = 0;
      int type = (*ptr)->type;

#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
      /* 16-byte long double is passed like a struct.  */
      if (type == FFI_TYPE_LONGDOUBLE)
	type = FFI_TYPE_STRUCT;
#endif

      /* Check how a structure type is passed.  */
      if (type == FFI_TYPE_STRUCT)
	{
	  type = ffi_check_struct_type (*ptr);

	  /* If we pass the struct via pointer, remember to 
	     retrieve the pointer later.  */
	  if (type == FFI_TYPE_POINTER)
	    deref_struct_pointer = 1;
	}

      /* Pointers are passed like UINTs of the same size.  */
      if (type == FFI_TYPE_POINTER)
#ifdef __s390x__
	type = FFI_TYPE_UINT64;
#else
	type = FFI_TYPE_UINT32;
#endif

      /* Now handle all primitive int/float data types.  */
      switch (type) 
	{
	  case FFI_TYPE_DOUBLE:
	    if (n_fpr < MAX_FPRARGS)
	      *p_arg = &p_fpr[n_fpr++];
	    else
	      *p_arg = &p_ov[n_ov], 
	      n_ov += sizeof (double) / sizeof (long);
	    break;
	
	  case FFI_TYPE_FLOAT:
	    if (n_fpr < MAX_FPRARGS)
	      *p_arg = &p_fpr[n_fpr++];
	    else
	      *p_arg = (char *)&p_ov[n_ov++] + sizeof (long) - 4;
	    break;
 
	  case FFI_TYPE_UINT64:
	  case FFI_TYPE_SINT64:
#ifdef __s390x__
	    if (n_gpr < MAX_GPRARGS)
	      *p_arg = &p_gpr[n_gpr++];
	    else
	      *p_arg = &p_ov[n_ov++];
#else
	    if (n_gpr == MAX_GPRARGS-1)
	      n_gpr = MAX_GPRARGS;
	    if (n_gpr < MAX_GPRARGS)
	      *p_arg = &p_gpr[n_gpr], n_gpr += 2;
	    else
	      *p_arg = &p_ov[n_ov], n_ov += 2;
#endif
	    break;
 
	  case FFI_TYPE_INT:
	  case FFI_TYPE_UINT32:
	  case FFI_TYPE_SINT32:
	    if (n_gpr < MAX_GPRARGS)
	      *p_arg = (char *)&p_gpr[n_gpr++] + sizeof (long) - 4;
	    else
	      *p_arg = (char *)&p_ov[n_ov++] + sizeof (long) - 4;
	    break;
 
	  case FFI_TYPE_UINT16:
	  case FFI_TYPE_SINT16:
	    if (n_gpr < MAX_GPRARGS)
	      *p_arg = (char *)&p_gpr[n_gpr++] + sizeof (long) - 2;
	    else
	      *p_arg = (char *)&p_ov[n_ov++] + sizeof (long) - 2;
	    break;

	  case FFI_TYPE_UINT8:
	  case FFI_TYPE_SINT8:
	    if (n_gpr < MAX_GPRARGS)
	      *p_arg = (char *)&p_gpr[n_gpr++] + sizeof (long) - 1;
	    else
	      *p_arg = (char *)&p_ov[n_ov++] + sizeof (long) - 1;
	    break;
 
	  default:
	    FFI_ASSERT (0);
	    break;
        }

      /* If this is a struct passed via pointer, we need to
	 actually retrieve that pointer.  */
      if (deref_struct_pointer)
	*p_arg = *(void **)*p_arg;
    }


  /* Call the target function.  */
  (closure->fun) (closure->cif, rvalue, avalue, closure->user_data);

  /* Convert the return value.  */
  switch (closure->cif->rtype->type)
    {
      /* Void is easy, and so is struct.  */
      case FFI_TYPE_VOID:
      case FFI_TYPE_STRUCT:
#if FFI_TYPE_LONGDOUBLE != FFI_TYPE_DOUBLE
      case FFI_TYPE_LONGDOUBLE:
#endif
	break;

      /* Floating point values are returned in fpr 0.  */
      case FFI_TYPE_FLOAT:
	p_fpr[0] = (long long) *(unsigned int *) rvalue << 32;
	break;

      case FFI_TYPE_DOUBLE:
	p_fpr[0] = *(unsigned long long *) rvalue;
	break;

      /* Integer values are returned in gpr 2 (and gpr 3
	 for 64-bit values on 31-bit machines).  */
      case FFI_TYPE_UINT64:
      case FFI_TYPE_SINT64:
#ifdef __s390x__
	p_gpr[0] = *(unsigned long *) rvalue;
#else
	p_gpr[0] = ((unsigned long *) rvalue)[0],
	p_gpr[1] = ((unsigned long *) rvalue)[1];
#endif
	break;

      case FFI_TYPE_POINTER:
      case FFI_TYPE_UINT32:
      case FFI_TYPE_UINT16:
      case FFI_TYPE_UINT8:
	p_gpr[0] = *(unsigned long *) rvalue;
	break;

      case FFI_TYPE_INT:
      case FFI_TYPE_SINT32:
      case FFI_TYPE_SINT16:
      case FFI_TYPE_SINT8:
	p_gpr[0] = *(signed long *) rvalue;
	break;

      default:
        FFI_ASSERT (0);
        break;
    }
}
 
/*======================== End of Routine ============================*/

/*====================================================================*/
/*                                                                    */
/* Name     - ffi_prep_closure_loc.                                   */
/*                                                                    */
/* Function - Prepare a FFI closure.                                  */
/*                                                                    */
/*====================================================================*/
 
ffi_status
ffi_prep_closure_loc (ffi_closure *closure,
		      ffi_cif *cif,
		      void (*fun) (ffi_cif *, void *, void **, void *),
		      void *user_data,
		      void *codeloc)
{
  if (cif->abi != FFI_SYSV)
    return FFI_BAD_ABI;

#ifndef __s390x__
  *(short *)&closure->tramp [0] = 0x0d10;   /* basr %r1,0 */
  *(short *)&closure->tramp [2] = 0x9801;   /* lm %r0,%r1,6(%r1) */
  *(short *)&closure->tramp [4] = 0x1006;
  *(short *)&closure->tramp [6] = 0x07f1;   /* br %r1 */
  *(long  *)&closure->tramp [8] = (long)codeloc;
  *(long  *)&closure->tramp[12] = (long)&ffi_closure_SYSV;
#else
  *(short *)&closure->tramp [0] = 0x0d10;   /* basr %r1,0 */
  *(short *)&closure->tramp [2] = 0xeb01;   /* lmg %r0,%r1,14(%r1) */
  *(short *)&closure->tramp [4] = 0x100e;
  *(short *)&closure->tramp [6] = 0x0004;
  *(short *)&closure->tramp [8] = 0x07f1;   /* br %r1 */
  *(long  *)&closure->tramp[16] = (long)codeloc;
  *(long  *)&closure->tramp[24] = (long)&ffi_closure_SYSV;
#endif 
 
  closure->cif = cif;
  closure->user_data = user_data;
  closure->fun = fun;
 
  return FFI_OK;
}

/*======================== End of Routine ============================*/