summaryrefslogtreecommitdiff
path: root/src/mesa/shader/slang/slang_assemble.c
blob: 0cba5d5d007f6ecb70a85af2dfddcc78da560c79 (plain)
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
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 2005-2006  Brian Paul   All Rights Reserved.
 *
 * 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
 * BRIAN PAUL 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.
 */

/**
 * \file slang_assemble.c
 * slang intermediate code assembler
 * \author Michal Krol
 */

#include "imports.h"
#include "slang_assemble.h"
#include "slang_compile.h"
#include "slang_storage.h"

/* slang_assembly */

static GLboolean
slang_assembly_construct(slang_assembly * assem)
{
   assem->type = slang_asm_none;
   return GL_TRUE;
}

static GLvoid
slang_assembly_destruct(slang_assembly * assem)
{
}

/*
 * slang_assembly_file
 */

GLvoid
_slang_assembly_file_ctr(slang_assembly_file * self)
{
   self->code = NULL;
   self->count = 0;
   self->capacity = 0;
}

GLvoid
slang_assembly_file_destruct(slang_assembly_file * file)
{
   GLuint i;

   for (i = 0; i < file->count; i++)
      slang_assembly_destruct(&file->code[i]);
   slang_alloc_free(file->code);
}

static GLboolean
push_new(slang_assembly_file * file)
{
   if (file->count == file->capacity) {
      GLuint n;

      if (file->capacity == 0)
         n = 256;
      else
         n = file->capacity * 2;
      file->code = (slang_assembly *)
         slang_alloc_realloc(file->code,
                             file->capacity * sizeof(slang_assembly),
                             n * sizeof(slang_assembly));
      if (file->code == NULL)
         return GL_FALSE;
      file->capacity = n;
   }
   if (!slang_assembly_construct(&file->code[file->count]))
      return GL_FALSE;
   file->count++;
   return GL_TRUE;
}

static GLboolean
push_gen(slang_assembly_file * file, slang_assembly_type type,
         GLfloat literal, GLuint label, GLuint size)
{
   slang_assembly *assem;

   if (!push_new(file))
      return GL_FALSE;
   assem = &file->code[file->count - 1];
   assem->type = type;
   assem->literal = literal;
   assem->param[0] = label;
   assem->param[1] = size;
   return GL_TRUE;
}

GLboolean
slang_assembly_file_push(slang_assembly_file * file, slang_assembly_type type)
{
   return push_gen(file, type, (GLfloat) 0, 0, 0);
}

GLboolean
slang_assembly_file_push_label(slang_assembly_file * file,
                               slang_assembly_type type, GLuint label)
{
   return push_gen(file, type, (GLfloat) 0, label, 0);
}

GLboolean
slang_assembly_file_push_label2(slang_assembly_file * file,
                                slang_assembly_type type, GLuint label1,
                                GLuint label2)
{
   return push_gen(file, type, (GLfloat) 0, label1, label2);
}

GLboolean
slang_assembly_file_push_literal(slang_assembly_file * file,
                                 slang_assembly_type type, GLfloat literal)
{
   return push_gen(file, type, literal, 0, 0);
}

#define PUSH slang_assembly_file_push
#define PLAB slang_assembly_file_push_label
#define PLAB2 slang_assembly_file_push_label2
#define PLIT slang_assembly_file_push_literal

/* slang_assembly_file_restore_point */

GLboolean
slang_assembly_file_restore_point_save(slang_assembly_file * file,
                                       slang_assembly_file_restore_point *
                                       point)
{
   point->count = file->count;
   return GL_TRUE;
}

GLboolean
slang_assembly_file_restore_point_load(slang_assembly_file * file,
                                       slang_assembly_file_restore_point *
                                       point)
{
   GLuint i;

   for (i = point->count; i < file->count; i++)
      slang_assembly_destruct(&file->code[i]);
   file->count = point->count;
   return GL_TRUE;
}

/* utility functions */

static GLboolean
sizeof_variable(slang_assemble_ctx * A, slang_type_specifier * spec,
                slang_type_qualifier qual, GLuint array_len, GLuint * size)
{
   slang_storage_aggregate agg;

   /* calculate the size of the variable's aggregate */
   if (!slang_storage_aggregate_construct(&agg))
      return GL_FALSE;
   if (!_slang_aggregate_variable
       (&agg, spec, array_len, A->space.funcs, A->space.structs,
        A->space.vars, A->mach, A->file, A->atoms)) {
      slang_storage_aggregate_destruct(&agg);
      return GL_FALSE;
   }
   *size += _slang_sizeof_aggregate(&agg);
   slang_storage_aggregate_destruct(&agg);

   /* for reference variables consider the additional address overhead */
   if (qual == slang_qual_out || qual == slang_qual_inout)
      *size += 4;

   return GL_TRUE;
}

static GLboolean
sizeof_variable2(slang_assemble_ctx * A, slang_variable * var, GLuint * size)
{
   var->address = *size;
   if (var->type.qualifier == slang_qual_out
       || var->type.qualifier == slang_qual_inout)
      var->address += 4;
   return sizeof_variable(A, &var->type.specifier, var->type.qualifier,
                          var->array_len, size);
}

static GLboolean
sizeof_variables(slang_assemble_ctx * A, slang_variable_scope * vars,
                 GLuint start, GLuint stop, GLuint * size)
{
   GLuint i;

   for (i = start; i < stop; i++)
      if (!sizeof_variable2(A, &vars->variables[i], size))
         return GL_FALSE;
   return GL_TRUE;
}

static GLboolean
collect_locals(slang_assemble_ctx * A, slang_operation * op, GLuint * size)
{
   GLuint i;

   if (!sizeof_variables(A, op->locals, 0, op->locals->num_variables, size))
      return GL_FALSE;
   for (i = 0; i < op->num_children; i++)
      if (!collect_locals(A, &op->children[i], size))
         return GL_FALSE;
   return GL_TRUE;
}

/* _slang_locate_function() */

slang_function *
_slang_locate_function(const slang_function_scope * funcs, slang_atom a_name,
                       const slang_operation * params, GLuint num_params,
                       const slang_assembly_name_space * space,
                       slang_atom_pool * atoms)
{
   GLuint i;

   for (i = 0; i < funcs->num_functions; i++) {
      GLuint j;
      slang_function *f = &funcs->functions[i];

      if (a_name != f->header.a_name)
         continue;
      if (f->param_count != num_params)
         continue;
      for (j = 0; j < num_params; j++) {
         slang_assembly_typeinfo ti;

         if (!slang_assembly_typeinfo_construct(&ti))
            return NULL;
         if (!_slang_typeof_operation_(&params[j], space, &ti, atoms)) {
            slang_assembly_typeinfo_destruct(&ti);
            return NULL;
         }
         if (!slang_type_specifier_equal
             (&ti.spec, &f->parameters->variables[j].type.specifier)) {
            slang_assembly_typeinfo_destruct(&ti);
            break;
         }
         slang_assembly_typeinfo_destruct(&ti);

         /* "out" and "inout" formal parameter requires the actual parameter to be l-value */
         if (!ti.can_be_referenced &&
             (f->parameters->variables[j].type.qualifier == slang_qual_out ||
              f->parameters->variables[j].type.qualifier == slang_qual_inout))
            break;
      }
      if (j == num_params)
         return f;
   }
   if (funcs->outer_scope != NULL)
      return _slang_locate_function(funcs->outer_scope, a_name, params,
                                    num_params, space, atoms);
   return NULL;
}

/* _slang_assemble_function() */

GLboolean
_slang_assemble_function(slang_assemble_ctx * A, slang_function * fun)
{
   GLuint param_size, local_size;
   GLuint skip, cleanup;

   fun->address = A->file->count;

   if (fun->body == NULL) {
      /* jump to the actual function body - we do not know it, so add
       * the instruction to fixup table
       */
      if (!slang_fixup_save(&fun->fixups, fun->address))
         return GL_FALSE;
      if (!PUSH(A->file, slang_asm_jump))
         return GL_FALSE;
      return GL_TRUE;
   }
   else {
      /* resolve all fixup table entries and delete it */
      GLuint i;
      for (i = 0; i < fun->fixups.count; i++)
         A->file->code[fun->fixups.table[i]].param[0] = fun->address;
      slang_fixup_table_free(&fun->fixups);
   }

   /* At this point traverse function formal parameters and code to calculate
    * total memory size to be allocated on the stack.
    * During this process the variables will be assigned local addresses to
    * reference them in the code.
    * No storage optimizations are performed so exclusive scopes are not
    * detected and shared.
    */

   /* calculate return value size */
   param_size = 0;
   if (fun->header.type.specifier.type != slang_spec_void)
      if (!sizeof_variable
          (A, &fun->header.type.specifier, slang_qual_none, 0, &param_size))
         return GL_FALSE;
   A->local.ret_size = param_size;

   /* calculate formal parameter list size */
   if (!sizeof_variables
       (A, fun->parameters, 0, fun->param_count, &param_size))
      return GL_FALSE;

   /* calculate local variables size - take into account the four-byte
    * return address and temporaries for various tasks (4 for addr and
    * 16 for swizzle temporaries).  these include variables from the
    * formal parameter scope and from the code
    */
   A->local.addr_tmp = param_size + 4;
   A->local.swizzle_tmp = param_size + 4 + 4;
   local_size = param_size + 4 + 4 + 16;
   if (!sizeof_variables
       (A, fun->parameters, fun->param_count, fun->parameters->num_variables,
        &local_size))
      return GL_FALSE;
   if (!collect_locals(A, fun->body, &local_size))
      return GL_FALSE;

   /* allocate local variable storage */
   if (!PLAB(A->file, slang_asm_local_alloc, local_size - param_size - 4))
      return GL_FALSE;

   /* mark a new frame for function variable storage */
   if (!PLAB(A->file, slang_asm_enter, local_size))
      return GL_FALSE;

   /* jump directly to the actual code */
   skip = A->file->count;
   if (!push_new(A->file))
      return GL_FALSE;
   A->file->code[skip].type = slang_asm_jump;

   /* all "return" statements will be directed here */
   A->flow.function_end = A->file->count;
   cleanup = A->file->count;
   if (!push_new(A->file))
      return GL_FALSE;
   A->file->code[cleanup].type = slang_asm_jump;

   /* execute the function body */
   A->file->code[skip].param[0] = A->file->count;
   if (!_slang_assemble_operation
       (A, fun->body, /*slang_ref_freelance */ slang_ref_forbid))
      return GL_FALSE;

   /* this is the end of the function - restore the old function frame */
   A->file->code[cleanup].param[0] = A->file->count;
   if (!PUSH(A->file, slang_asm_leave))
      return GL_FALSE;

   /* free local variable storage */
   if (!PLAB(A->file, slang_asm_local_free, local_size - param_size - 4))
      return GL_FALSE;

   /* return from the function */
   if (!PUSH(A->file, slang_asm_return))
      return GL_FALSE;

   return GL_TRUE;
}

GLboolean
_slang_cleanup_stack(slang_assemble_ctx * A, slang_operation * op)
{
   slang_assembly_typeinfo ti;
   GLuint size = 0;

   /* get type info of the operation and calculate its size */
   if (!slang_assembly_typeinfo_construct(&ti))
      return GL_FALSE;
   if (!_slang_typeof_operation(A, op, &ti)) {
      slang_assembly_typeinfo_destruct(&ti);
      return GL_FALSE;
   }
   if (ti.spec.type != slang_spec_void) {
      if (A->ref == slang_ref_force) {
         size = 4;
      }
      else if (!sizeof_variable(A, &ti.spec, slang_qual_none, 0, &size)) {
         slang_assembly_typeinfo_destruct(&ti);
         return GL_FALSE;
      }
   }
   slang_assembly_typeinfo_destruct(&ti);

   /* if nonzero, free it from the stack */
   if (size != 0) {
      if (!PLAB(A->file, slang_asm_local_free, size))
         return GL_FALSE;
   }

   return GL_TRUE;
}

/* _slang_assemble_operation() */

static GLboolean
dereference_basic(slang_assemble_ctx * A, slang_storage_type type,
                  GLuint * size, slang_swizzle * swz, GLboolean is_swizzled)
{
   GLuint src_offset;
   slang_assembly_type ty;

   *size -= _slang_sizeof_type(type);

   /* If swizzling is taking place, we are forced to use scalar
    * operations, even if we have vec4 instructions enabled (this
    * should be actually done with special vec4 shuffle instructions).
    * Adjust the size and calculate the offset within source variable
    * to read.
    */
   if (is_swizzled)
      src_offset = swz->swizzle[*size / 4] * 4;
   else
      src_offset = *size;

   /* dereference data slot of a basic type */
   if (!PLAB2(A->file, slang_asm_local_addr, A->local.addr_tmp, 4))
      return GL_FALSE;
   if (!PUSH(A->file, slang_asm_addr_deref))
      return GL_FALSE;
   if (src_offset != 0) {
      if (!PLAB(A->file, slang_asm_addr_push, src_offset))
         return GL_FALSE;
      if (!PUSH(A->file, slang_asm_addr_add))
         return GL_FALSE;
   }

   switch (type) {
   case slang_stor_bool:
      ty = slang_asm_bool_deref;
      break;
   case slang_stor_int:
      ty = slang_asm_int_deref;
      break;
   case slang_stor_float:
      ty = slang_asm_float_deref;
      break;
#if defined(USE_X86_ASM) || defined(SLANG_X86)
   case slang_stor_vec4:
      ty = slang_asm_vec4_deref;
      break;
#endif
   default:
      _mesa_problem(NULL, "Unexpected arr->type in dereference_basic");
      ty = slang_asm_none;
   }

   return PUSH(A->file, ty);
}

static GLboolean
dereference_aggregate(slang_assemble_ctx * A,
                      const slang_storage_aggregate * agg, GLuint * size,
                      slang_swizzle * swz, GLboolean is_swizzled)
{
   GLuint i;

   for (i = agg->count; i > 0; i--) {
      const slang_storage_array *arr = &agg->arrays[i - 1];
      GLuint j;

      for (j = arr->length; j > 0; j--) {
         if (arr->type == slang_stor_aggregate) {
            if (!dereference_aggregate
                (A, arr->aggregate, size, swz, is_swizzled))
               return GL_FALSE;
         }
         else {
            if (is_swizzled && arr->type == slang_stor_vec4) {
               if (!dereference_basic
                   (A, slang_stor_float, size, swz, is_swizzled))
                  return GL_FALSE;
               if (!dereference_basic
                   (A, slang_stor_float, size, swz, is_swizzled))
                  return GL_FALSE;
               if (!dereference_basic
                   (A, slang_stor_float, size, swz, is_swizzled))
                  return GL_FALSE;
               if (!dereference_basic
                   (A, slang_stor_float, size, swz, is_swizzled))
                  return GL_FALSE;
            }
            else {
               if (!dereference_basic(A, arr->type, size, swz, is_swizzled))
                  return GL_FALSE;
            }
         }
      }
   }

   return GL_TRUE;
}

GLboolean
_slang_dereference(slang_assemble_ctx * A, slang_operation * op)
{
   slang_assembly_typeinfo ti;
   GLboolean result = GL_FALSE;
   slang_storage_aggregate agg;
   GLuint size;

   /* get type information of the given operation */
   if (!slang_assembly_typeinfo_construct(&ti))
      return GL_FALSE;
   if (!_slang_typeof_operation(A, op, &ti))
      goto end1;

   /* construct aggregate from the type info */
   if (!slang_storage_aggregate_construct(&agg))
      goto end1;
   if (!_slang_aggregate_variable
       (&agg, &ti.spec, ti.array_len, A->space.funcs, A->space.structs,
        A->space.vars, A->mach, A->file, A->atoms))
      goto end;

   /* dereference the resulting aggregate */
   size = _slang_sizeof_aggregate(&agg);
   result = dereference_aggregate(A, &agg, &size, &ti.swz, ti.is_swizzled);

 end:
   slang_storage_aggregate_destruct(&agg);
 end1:
   slang_assembly_typeinfo_destruct(&ti);
   return result;
}

GLboolean
_slang_assemble_function_call(slang_assemble_ctx * A, slang_function * fun,
                              slang_operation * params, GLuint param_count,
                              GLboolean assignment)
{
   GLuint i;
   slang_swizzle p_swz[64];
   slang_ref_type p_ref[64];

   /* TODO: fix this, allocate dynamically */
   if (param_count > 64)
      return GL_FALSE;

   /* make room for the return value, if any */
   if (fun->header.type.specifier.type != slang_spec_void) {
      GLuint ret_size = 0;

      if (!sizeof_variable
          (A, &fun->header.type.specifier, slang_qual_none, 0, &ret_size))
         return GL_FALSE;
      if (!PLAB(A->file, slang_asm_local_alloc, ret_size))
         return GL_FALSE;
   }

   /* push the actual parameters on the stack */
   for (i = 0; i < param_count; i++) {
      if (fun->parameters->variables[i].type.qualifier == slang_qual_inout ||
          fun->parameters->variables[i].type.qualifier == slang_qual_out) {
         if (!PLAB2(A->file, slang_asm_local_addr, A->local.addr_tmp, 4))
            return GL_FALSE;
         /* TODO: optimize the "out" parameter case */
         if (!_slang_assemble_operation(A, &params[i], slang_ref_force))
            return GL_FALSE;
         p_swz[i] = A->swz;
         p_ref[i] = A->ref;
         if (!PUSH(A->file, slang_asm_addr_copy))
            return GL_FALSE;
         if (!PUSH(A->file, slang_asm_addr_deref))
            return GL_FALSE;
         if (i == 0 && assignment) {
            /* duplicate the resulting address */
            if (!PLAB2(A->file, slang_asm_local_addr, A->local.addr_tmp, 4))
               return GL_FALSE;
            if (!PUSH(A->file, slang_asm_addr_deref))
               return GL_FALSE;
         }
         if (!_slang_dereference(A, &params[i]))
            return GL_FALSE;
      }
      else {
         if (!_slang_assemble_operation(A, &params[i], slang_ref_forbid))
            return GL_FALSE;
         p_swz[i] = A->swz;
         p_ref[i] = A->ref;
      }
   }

   /* call the function */
   if (!PLAB(A->file, slang_asm_call, fun->address))
      return GL_FALSE;

   /* pop the parameters from the stack */
   for (i = param_count; i > 0; i--) {
      GLuint j = i - 1;

      A->swz = p_swz[j];
      A->ref = p_ref[j];
      if (fun->parameters->variables[j].type.qualifier == slang_qual_inout ||
          fun->parameters->variables[j].type.qualifier == slang_qual_out) {
         /* for output parameter copy the contents of the formal parameter
          * back to the original actual parameter
          */
         if (!_slang_assemble_assignment(A, &params[j]))
            return GL_FALSE;
         /* pop the actual parameter's address */
         if (!PLAB(A->file, slang_asm_local_free, 4))
            return GL_FALSE;
      }
      else {
         /* pop the value of the parameter */
         if (!_slang_cleanup_stack(A, &params[j]))
            return GL_FALSE;
      }
   }

   return GL_TRUE;
}

GLboolean
_slang_assemble_function_call_name(slang_assemble_ctx * A, const char *name,
                                   slang_operation * params,
                                   GLuint param_count, GLboolean assignment)
{
   slang_atom atom;
   slang_function *fun;

   atom = slang_atom_pool_atom(A->atoms, name);
   if (atom == SLANG_ATOM_NULL)
      return GL_FALSE;
   fun =
      _slang_locate_function(A->space.funcs, atom, params, param_count,
                             &A->space, A->atoms);
   if (fun == NULL)
      return GL_FALSE;
   return _slang_assemble_function_call(A, fun, params, param_count,
                                        assignment);
}

static GLboolean
assemble_function_call_name_dummyint(slang_assemble_ctx * A, const char *name,
                                     slang_operation * params)
{
   slang_operation p[2];
   GLboolean result;

   p[0] = params[0];
   if (!slang_operation_construct(&p[1]))
      return GL_FALSE;
   p[1].type = slang_oper_literal_int;
   result = _slang_assemble_function_call_name(A, name, p, 2, GL_FALSE);
   slang_operation_destruct(&p[1]);
   return result;
}

static const struct
{
   const char *name;
   slang_assembly_type code1, code2;
} inst[] = {
   /* core */
   {"float_add", slang_asm_float_add, slang_asm_float_copy},
   {"float_multiply", slang_asm_float_multiply, slang_asm_float_copy},
   {"float_divide", slang_asm_float_divide, slang_asm_float_copy},
   {"float_negate", slang_asm_float_negate, slang_asm_float_copy},
   {"float_less", slang_asm_float_less, slang_asm_bool_copy},
   {"float_equal", slang_asm_float_equal_exp, slang_asm_bool_copy},
   {"float_to_int", slang_asm_float_to_int, slang_asm_int_copy},
   {"float_sine", slang_asm_float_sine, slang_asm_float_copy},
   {"float_arcsine", slang_asm_float_arcsine, slang_asm_float_copy},
   {"float_arctan", slang_asm_float_arctan, slang_asm_float_copy},
   {"float_power", slang_asm_float_power, slang_asm_float_copy},
   {"float_log2", slang_asm_float_log2, slang_asm_float_copy},
   {"float_floor", slang_asm_float_floor, slang_asm_float_copy},
   {"float_ceil", slang_asm_float_ceil, slang_asm_float_copy},
   {"float_noise1", slang_asm_float_noise1, slang_asm_float_copy},
   {"float_noise2", slang_asm_float_noise2, slang_asm_float_copy},
   {"float_noise3", slang_asm_float_noise3, slang_asm_float_copy},
   {"float_noise4", slang_asm_float_noise4, slang_asm_float_copy},
   {"int_to_float", slang_asm_int_to_float, slang_asm_float_copy},
   {"vec4_tex1d", slang_asm_vec4_tex1d, slang_asm_none},
   {"vec4_tex2d", slang_asm_vec4_tex2d, slang_asm_none},
   {"vec4_tex3d", slang_asm_vec4_tex3d, slang_asm_none},
   {"vec4_texcube", slang_asm_vec4_texcube, slang_asm_none},
   {"vec4_shad1d", slang_asm_vec4_shad1d, slang_asm_none},
   {"vec4_shad2d", slang_asm_vec4_shad2d, slang_asm_none},
    /* GL_MESA_shader_debug */
   {"float_print", slang_asm_float_deref, slang_asm_float_print},
   {"int_print", slang_asm_int_deref, slang_asm_int_print},
   {"bool_print", slang_asm_bool_deref, slang_asm_bool_print},
   /* vec4 */
   {"float_to_vec4", slang_asm_float_to_vec4, slang_asm_none},
   {"vec4_add", slang_asm_vec4_add, slang_asm_none},
   {"vec4_subtract", slang_asm_vec4_subtract, slang_asm_none},
   {"vec4_multiply", slang_asm_vec4_multiply, slang_asm_none},
   {"vec4_divide", slang_asm_vec4_divide, slang_asm_none},
   {"vec4_negate", slang_asm_vec4_negate, slang_asm_none},
   {"vec4_dot", slang_asm_vec4_dot, slang_asm_none},
   {NULL, slang_asm_none, slang_asm_none}
};

static GLboolean
call_asm_instruction(slang_assemble_ctx * A, slang_atom a_name)
{
   const char *id;
   GLuint i;

   id = slang_atom_pool_id(A->atoms, a_name);

   for (i = 0; inst[i].name != NULL; i++)
      if (slang_string_compare(id, inst[i].name) == 0)
         break;
   if (inst[i].name == NULL)
      return GL_FALSE;

   if (!PLAB2(A->file, inst[i].code1, 4, 0))
      return GL_FALSE;
   if (inst[i].code2 != slang_asm_none)
      if (!PLAB2(A->file, inst[i].code2, 4, 0))
         return GL_FALSE;

   /* clean-up the stack from the remaining dst address */
   if (!PLAB(A->file, slang_asm_local_free, 4))
      return GL_FALSE;

   return GL_TRUE;
}

static GLboolean
equality_aggregate(slang_assemble_ctx * A,
                   const slang_storage_aggregate * agg, GLuint * index,
                   GLuint size, GLuint z_label)
{
   GLuint i;

   for (i = 0; i < agg->count; i++) {
      const slang_storage_array *arr = &agg->arrays[i];
      GLuint j;

      for (j = 0; j < arr->length; j++) {
         if (arr->type == slang_stor_aggregate) {
            if (!equality_aggregate(A, arr->aggregate, index, size, z_label))
               return GL_FALSE;
         }
         else {
#if defined(USE_X86_ASM) || defined(SLANG_X86)
            if (arr->type == slang_stor_vec4) {
               if (!PLAB2
                   (A->file, slang_asm_vec4_equal_int, size + *index, *index))
                  return GL_FALSE;
            }
            else
#endif
            if (!PLAB2
                   (A->file, slang_asm_float_equal_int, size + *index,
                       *index))
               return GL_FALSE;

            *index += _slang_sizeof_type(arr->type);
            if (!PLAB(A->file, slang_asm_jump_if_zero, z_label))
               return GL_FALSE;
         }
      }
   }

   return GL_TRUE;
}

static GLboolean
equality(slang_assemble_ctx * A, slang_operation * op, GLboolean equal)
{
   slang_assembly_typeinfo ti;
   GLboolean result = GL_FALSE;
   slang_storage_aggregate agg;
   GLuint index, size;
   GLuint skip_jump, true_label, true_jump, false_label, false_jump;

   /* get type of operation */
   if (!slang_assembly_typeinfo_construct(&ti))
      return GL_FALSE;
   if (!_slang_typeof_operation(A, op, &ti))
      goto end1;

   /* convert it to an aggregate */
   if (!slang_storage_aggregate_construct(&agg))
      goto end1;
   if (!_slang_aggregate_variable
       (&agg, &ti.spec, 0, A->space.funcs, A->space.structs, A->space.vars,
        A->mach, A->file, A->atoms))
      goto end;

   /* compute the size of the agregate - there are two such aggregates on the stack */
   size = _slang_sizeof_aggregate(&agg);

   /* jump to the actual data-comparison code */
   skip_jump = A->file->count;
   if (!PUSH(A->file, slang_asm_jump))
      goto end;

   /* pop off the stack the compared data and push 1 */
   true_label = A->file->count;
   if (!PLAB(A->file, slang_asm_local_free, size * 2))
      goto end;
   if (!PLIT(A->file, slang_asm_bool_push, (GLfloat) 1))
      goto end;
   true_jump = A->file->count;
   if (!PUSH(A->file, slang_asm_jump))
      goto end;

   false_label = A->file->count;
   if (!PLAB(A->file, slang_asm_local_free, size * 2))
      goto end;
   if (!PLIT(A->file, slang_asm_bool_push, (GLfloat) 0))
      goto end;
   false_jump = A->file->count;
   if (!PUSH(A->file, slang_asm_jump))
      goto end;

   A->file->code[skip_jump].param[0] = A->file->count;

   /* compare the data on stack, it will eventually jump either to true or false label */
   index = 0;
   if (!equality_aggregate
       (A, &agg, &index, size, equal ? false_label : true_label))
      goto end;
   if (!PLAB(A->file, slang_asm_jump, equal ? true_label : false_label))
      goto end;

   A->file->code[true_jump].param[0] = A->file->count;
   A->file->code[false_jump].param[0] = A->file->count;

   result = GL_TRUE;
 end:
   slang_storage_aggregate_destruct(&agg);
 end1:
   slang_assembly_typeinfo_destruct(&ti);
   return result;
}

static GLboolean
handle_subscript(slang_assemble_ctx * A, slang_assembly_typeinfo * tie,
                 slang_assembly_typeinfo * tia, slang_operation * op,
                 slang_ref_type ref)
{
   GLuint asize = 0, esize = 0;

   /* get type info of the master expression (matrix, vector or an array */
   if (!_slang_typeof_operation(A, &op->children[0], tia))
      return GL_FALSE;
   if (!sizeof_variable
       (A, &tia->spec, slang_qual_none, tia->array_len, &asize))
      return GL_FALSE;

   /* get type info of the result (matrix column, vector row or array element) */
   if (!_slang_typeof_operation(A, op, tie))
      return GL_FALSE;
   if (!sizeof_variable(A, &tie->spec, slang_qual_none, 0, &esize))
      return GL_FALSE;

   /* assemble the master expression */
   if (!_slang_assemble_operation(A, &op->children[0], ref))
      return GL_FALSE;

   /* when indexing an l-value swizzle, push the swizzle_tmp */
   if (ref == slang_ref_force && tia->is_swizzled)
      if (!PLAB2(A->file, slang_asm_local_addr, A->local.swizzle_tmp, 16))
         return GL_FALSE;

   /* assemble the subscript expression */
   if (!_slang_assemble_operation(A, &op->children[1], slang_ref_forbid))
      return GL_FALSE;

   if (ref == slang_ref_force && tia->is_swizzled) {
      GLuint i;

      /* copy the swizzle indexes to the swizzle_tmp */
      for (i = 0; i < tia->swz.num_components; i++) {
         if (!PLAB2(A->file, slang_asm_local_addr, A->local.swizzle_tmp, 16))
            return GL_FALSE;
         if (!PLAB(A->file, slang_asm_addr_push, i * 4))
            return GL_FALSE;
         if (!PUSH(A->file, slang_asm_addr_add))
            return GL_FALSE;
         if (!PLAB(A->file, slang_asm_addr_push, tia->swz.swizzle[i]))
            return GL_FALSE;
         if (!PUSH(A->file, slang_asm_addr_copy))
            return GL_FALSE;
         if (!PLAB(A->file, slang_asm_local_free, 4))
            return GL_FALSE;
      }

      /* offset the pushed swizzle_tmp address and dereference it */
      if (!PUSH(A->file, slang_asm_int_to_addr))
         return GL_FALSE;
      if (!PLAB(A->file, slang_asm_addr_push, 4))
         return GL_FALSE;
      if (!PUSH(A->file, slang_asm_addr_multiply))
         return GL_FALSE;
      if (!PUSH(A->file, slang_asm_addr_add))
         return GL_FALSE;
      if (!PUSH(A->file, slang_asm_addr_deref))
         return GL_FALSE;
   }
   else {
      /* convert the integer subscript to a relative address */
      if (!PUSH(A->file, slang_asm_int_to_addr))
         return GL_FALSE;
   }

   if (!PLAB(A->file, slang_asm_addr_push, esize))
      return GL_FALSE;
   if (!PUSH(A->file, slang_asm_addr_multiply))
      return GL_FALSE;

   if (ref == slang_ref_force) {
      /* offset the base address with the relative address */
      if (!PUSH(A->file, slang_asm_addr_add))
         return GL_FALSE;
   }
   else {
      GLuint i;

      /* move the selected element to the beginning of the master expression */
      for (i = 0; i < esize; i += 4)
         if (!PLAB2
             (A->file, slang_asm_float_move, asize - esize + i + 4, i + 4))
            return GL_FALSE;
      if (!PLAB(A->file, slang_asm_local_free, 4))
         return GL_FALSE;

      /* free the rest of the master expression */
      if (!PLAB(A->file, slang_asm_local_free, asize - esize))
         return GL_FALSE;
   }

   return GL_TRUE;
}

static GLboolean
handle_field(slang_assemble_ctx * A, slang_assembly_typeinfo * tia,
             slang_assembly_typeinfo * tib, slang_operation * op,
             slang_ref_type ref)
{
   /* get type info of the result (field or swizzle) */
   if (!_slang_typeof_operation(A, op, tia))
      return GL_FALSE;

   /* get type info of the master expression being accessed (struct or vector) */
   if (!_slang_typeof_operation(A, &op->children[0], tib))
      return GL_FALSE;

   /* if swizzling a vector in-place, the swizzle temporary is needed */
   if (ref == slang_ref_forbid && tia->is_swizzled)
      if (!PLAB2(A->file, slang_asm_local_addr, A->local.swizzle_tmp, 16))
         return GL_FALSE;

   /* assemble the master expression */
   if (!_slang_assemble_operation(A, &op->children[0], ref))
      return GL_FALSE;

   /* assemble the field expression */
   if (tia->is_swizzled) {
      if (ref == slang_ref_force) {
#if 0
         if (tia->swz.num_components == 1) {
            /* simple case - adjust the vector's address to point to
             * the selected component
             */
            if (!PLAB(file, slang_asm_addr_push, tia->swz.swizzle[0] * 4))
               return 0;
            if (!PUSH(file, slang_asm_addr_add))
               return 0;
         }
         else
#endif
         {
            /* two or more vector components are being referenced -
             * the so-called write mask must be passed to the upper
             * operations and applied when assigning value to this swizzle
             */
            A->swz = tia->swz;
         }
      }
      else {
         /* swizzle the vector in-place using the swizzle temporary */
         if (!_slang_assemble_constructor_from_swizzle
             (A, &tia->swz, &tia->spec, &tib->spec))
            return GL_FALSE;
      }
   }
   else {
      GLuint i, struct_size = 0, field_offset = 0, field_size = 0;

      /*
       * Calculate struct size, field offset and field size.
       */
      for (i = 0; i < tib->spec._struct->fields->num_variables; i++) {
         slang_variable *field;
         slang_storage_aggregate agg;
         GLuint size;

         field = &tib->spec._struct->fields->variables[i];
         if (!slang_storage_aggregate_construct(&agg))
            return GL_FALSE;
         if (!_slang_aggregate_variable
             (&agg, &field->type.specifier, field->array_len, A->space.funcs,
              A->space.structs, A->space.vars, A->mach, A->file, A->atoms)) {
            slang_storage_aggregate_destruct(&agg);
            return GL_FALSE;
         }
         size = _slang_sizeof_aggregate(&agg);
         slang_storage_aggregate_destruct(&agg);

         if (op->a_id == field->a_name) {
            field_size = size;
            field_offset = struct_size;
         }
         struct_size += size;
      }

      if (ref == slang_ref_force) {
         GLboolean shift;

         /*
          * OPTIMIZATION: If selecting first field, no address shifting
          * is needed.
          */
         shift = (field_offset != 0);

         if (shift) {
            if (!PLAB(A->file, slang_asm_addr_push, field_offset))
               return GL_FALSE;
            if (!PUSH(A->file, slang_asm_addr_add))
               return GL_FALSE;
         }
      }
      else {
         GLboolean relocate, shrink;
         GLuint free_b = 0;

         /*
          * OPTIMIZATION: If selecting last field, no relocation is needed.
          */
         relocate = (field_offset != (struct_size - field_size));

         /*
          * OPTIMIZATION: If field and struct sizes are equal, no partial
          * free is needed.
          */
         shrink = (field_size != struct_size);

         if (relocate) {
            GLuint i;

            /*
             * Move the selected element to the end of the master expression.
             * Do it in reverse order to avoid overwriting itself.
             */
            if (!PLAB(A->file, slang_asm_addr_push, field_offset))
               return GL_FALSE;
            for (i = field_size; i > 0; i -= 4)
               if (!PLAB2
                   (A->file, slang_asm_float_move,
                    struct_size - field_size + i, i))
                  return GL_FALSE;
            free_b += 4;
         }

         if (shrink) {
            /* free the rest of the master expression */
            free_b += struct_size - field_size;
         }

         if (free_b) {
            if (!PLAB(A->file, slang_asm_local_free, free_b))
               return GL_FALSE;
         }
      }
   }

   return GL_TRUE;
}

GLboolean
_slang_assemble_operation(slang_assemble_ctx * A, slang_operation * op,
                          slang_ref_type ref)
{
   /* set default results */
   A->ref = /*(ref == slang_ref_freelance) ? slang_ref_force : */ ref;
   A->swz.num_components = 0;

   switch (op->type) {
   case slang_oper_block_no_new_scope:
   case slang_oper_block_new_scope:
      {
         GLuint i;

         for (i = 0; i < op->num_children; i++) {
            if (!_slang_assemble_operation
                (A, &op->children[i],
                 slang_ref_forbid /*slang_ref_freelance */ ))
               return GL_FALSE;
            if (!_slang_cleanup_stack(A, &op->children[i]))
               return GL_FALSE;
         }
      }
      break;
   case slang_oper_variable_decl:
      {
         GLuint i;
         slang_operation assign;
         GLboolean result;

         /* Construct assignment expression placeholder. */
         if (!slang_operation_construct(&assign))
            return GL_FALSE;
         assign.type = slang_oper_assign;
         assign.children =
            (slang_operation *) slang_alloc_malloc(2 *
                                                   sizeof(slang_operation));
         if (assign.children == NULL) {
            slang_operation_destruct(&assign);
            return GL_FALSE;
         }
         for (assign.num_children = 0; assign.num_children < 2;
              assign.num_children++)
            if (!slang_operation_construct
                (&assign.children[assign.num_children])) {
               slang_operation_destruct(&assign);
               return GL_FALSE;
            }

         result = GL_TRUE;
         for (i = 0; i < op->num_children; i++) {
            slang_variable *var;

            var =
               _slang_locate_variable(op->children[i].locals,
                                      op->children[i].a_id, GL_TRUE);
            if (var == NULL) {
               result = GL_FALSE;
               break;
            }
            if (var->initializer == NULL)
               continue;

            if (!slang_operation_copy(&assign.children[0], &op->children[i])
                || !slang_operation_copy(&assign.children[1],
                                         var->initializer)
                || !_slang_assemble_assign(A, &assign, "=", slang_ref_forbid)
                || !_slang_cleanup_stack(A, &assign)) {
               result = GL_FALSE;
               break;
            }
         }
         slang_operation_destruct(&assign);
         if (!result)
            return GL_FALSE;
      }
      break;
   case slang_oper_asm:
      {
         GLuint i;
         if (!_slang_assemble_operation(A, &op->children[0], slang_ref_force))
            return GL_FALSE;
         for (i = 1; i < op->num_children; i++)
            if (!_slang_assemble_operation
                (A, &op->children[i], slang_ref_forbid))
               return GL_FALSE;
         if (!call_asm_instruction(A, op->a_id))
            return GL_FALSE;
      }
      break;
   case slang_oper_break:
      if (!PLAB(A->file, slang_asm_jump, A->flow.loop_end))
         return GL_FALSE;
      break;
   case slang_oper_continue:
      if (!PLAB(A->file, slang_asm_jump, A->flow.loop_start))
         return GL_FALSE;
      break;
   case slang_oper_discard:
      if (!PUSH(A->file, slang_asm_discard))
         return GL_FALSE;
      if (!PUSH(A->file, slang_asm_exit))
         return GL_FALSE;
      break;
   case slang_oper_return:
      if (A->local.ret_size != 0) {
         /* push the result's address */
         if (!PLAB2(A->file, slang_asm_local_addr, 0, A->local.ret_size))
            return GL_FALSE;
         if (!_slang_assemble_operation
             (A, &op->children[0], slang_ref_forbid))
            return GL_FALSE;

         A->swz.num_components = 0;
         /* assign the operation to the function result (it was reserved on the stack) */
         if (!_slang_assemble_assignment(A, op->children))
            return GL_FALSE;

         if (!PLAB(A->file, slang_asm_local_free, 4))
            return GL_FALSE;
      }
      if (!PLAB(A->file, slang_asm_jump, A->flow.function_end))
         return GL_FALSE;
      break;
   case slang_oper_expression:
      if (ref == slang_ref_force)
         return GL_FALSE;
      if (!_slang_assemble_operation(A, &op->children[0], ref))
         return GL_FALSE;
      break;
   case slang_oper_if:
      if (!_slang_assemble_if(A, op))
         return GL_FALSE;
      break;
   case slang_oper_while:
      if (!_slang_assemble_while(A, op))
         return GL_FALSE;
      break;
   case slang_oper_do:
      if (!_slang_assemble_do(A, op))
         return GL_FALSE;
      break;
   case slang_oper_for:
      if (!_slang_assemble_for(A, op))
         return GL_FALSE;
      break;
   case slang_oper_void:
      break;
   case slang_oper_literal_bool:
      if (ref == slang_ref_force)
         return GL_FALSE;
      if (!PLIT(A->file, slang_asm_bool_push, op->literal))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_literal_int:
      if (ref == slang_ref_force)
         return GL_FALSE;
      if (!PLIT(A->file, slang_asm_int_push, op->literal))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_literal_float:
      if (ref == slang_ref_force)
         return GL_FALSE;
      if (!PLIT(A->file, slang_asm_float_push, op->literal))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_identifier:
      {
         slang_variable *var;
         GLuint size;

         /* find the variable and calculate its size */
         var = _slang_locate_variable(op->locals, op->a_id, GL_TRUE);
         if (var == NULL)
            return GL_FALSE;
         size = 0;
         if (!sizeof_variable
             (A, &var->type.specifier, slang_qual_none, var->array_len,
              &size))
            return GL_FALSE;

         /* prepare stack for dereferencing */
         if (ref == slang_ref_forbid)
            if (!PLAB2(A->file, slang_asm_local_addr, A->local.addr_tmp, 4))
               return GL_FALSE;

         /* push the variable's address */
         if (var->global) {
            if (!PLAB(A->file, slang_asm_global_addr, var->address))
               return GL_FALSE;
         }
         else {
            if (!PLAB2(A->file, slang_asm_local_addr, var->address, size))
               return GL_FALSE;
         }

         /* perform the dereference */
         if (ref == slang_ref_forbid) {
            if (!PUSH(A->file, slang_asm_addr_copy))
               return GL_FALSE;
            if (!PLAB(A->file, slang_asm_local_free, 4))
               return GL_FALSE;
            if (!_slang_dereference(A, op))
               return GL_FALSE;
         }
      }
      break;
   case slang_oper_sequence:
      if (ref == slang_ref_force)
         return GL_FALSE;
      if (!_slang_assemble_operation(A, &op->children[0],
                                     slang_ref_forbid /*slang_ref_freelance */ ))
         return GL_FALSE;
      if (!_slang_cleanup_stack(A, &op->children[0]))
         return GL_FALSE;
      if (!_slang_assemble_operation(A, &op->children[1], slang_ref_forbid))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_assign:
      if (!_slang_assemble_assign(A, op, "=", ref))
         return GL_FALSE;
      break;
   case slang_oper_addassign:
      if (!_slang_assemble_assign(A, op, "+=", ref))
         return GL_FALSE;
      A->ref = ref;
      break;
   case slang_oper_subassign:
      if (!_slang_assemble_assign(A, op, "-=", ref))
         return GL_FALSE;
      A->ref = ref;
      break;
   case slang_oper_mulassign:
      if (!_slang_assemble_assign(A, op, "*=", ref))
         return GL_FALSE;
      A->ref = ref;
      break;
      /*case slang_oper_modassign: */
      /*case slang_oper_lshassign: */
      /*case slang_oper_rshassign: */
      /*case slang_oper_orassign: */
      /*case slang_oper_xorassign: */
      /*case slang_oper_andassign: */
   case slang_oper_divassign:
      if (!_slang_assemble_assign(A, op, "/=", ref))
         return GL_FALSE;
      A->ref = ref;
      break;
   case slang_oper_select:
      if (!_slang_assemble_select(A, op))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_logicalor:
      if (!_slang_assemble_logicalor(A, op))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_logicaland:
      if (!_slang_assemble_logicaland(A, op))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_logicalxor:
      if (!_slang_assemble_function_call_name(A, "^^", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
      /*case slang_oper_bitor: */
      /*case slang_oper_bitxor: */
      /*case slang_oper_bitand: */
   case slang_oper_less:
      if (!_slang_assemble_function_call_name(A, "<", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_greater:
      if (!_slang_assemble_function_call_name(A, ">", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_lessequal:
      if (!_slang_assemble_function_call_name(A, "<=", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_greaterequal:
      if (!_slang_assemble_function_call_name(A, ">=", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
      /*case slang_oper_lshift: */
      /*case slang_oper_rshift: */
   case slang_oper_add:
      if (!_slang_assemble_function_call_name(A, "+", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_subtract:
      if (!_slang_assemble_function_call_name(A, "-", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_multiply:
      if (!_slang_assemble_function_call_name(A, "*", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
      /*case slang_oper_modulus: */
   case slang_oper_divide:
      if (!_slang_assemble_function_call_name(A, "/", op->children, 2, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_equal:
      if (!_slang_assemble_operation(A, &op->children[0], slang_ref_forbid))
         return GL_FALSE;
      if (!_slang_assemble_operation(A, &op->children[1], slang_ref_forbid))
         return GL_FALSE;
      if (!equality(A, op->children, GL_TRUE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_notequal:
      if (!_slang_assemble_operation(A, &op->children[0], slang_ref_forbid))
         return GL_FALSE;
      if (!_slang_assemble_operation(A, &op->children[1], slang_ref_forbid))
         return GL_FALSE;
      if (!equality(A, op->children, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_preincrement:
      if (!_slang_assemble_assign(A, op, "++", ref))
         return GL_FALSE;
      A->ref = ref;
      break;
   case slang_oper_predecrement:
      if (!_slang_assemble_assign(A, op, "--", ref))
         return GL_FALSE;
      A->ref = ref;
      break;
   case slang_oper_plus:
      if (!_slang_dereference(A, op))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_minus:
      if (!_slang_assemble_function_call_name
          (A, "-", op->children, 1, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
      /*case slang_oper_complement: */
   case slang_oper_not:
      if (!_slang_assemble_function_call_name
          (A, "!", op->children, 1, GL_FALSE))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_subscript:
      {
         slang_assembly_typeinfo ti_arr, ti_elem;

         if (!slang_assembly_typeinfo_construct(&ti_arr))
            return GL_FALSE;
         if (!slang_assembly_typeinfo_construct(&ti_elem)) {
            slang_assembly_typeinfo_destruct(&ti_arr);
            return GL_FALSE;
         }
         if (!handle_subscript(A, &ti_elem, &ti_arr, op, ref)) {
            slang_assembly_typeinfo_destruct(&ti_arr);
            slang_assembly_typeinfo_destruct(&ti_elem);
            return GL_FALSE;
         }
         slang_assembly_typeinfo_destruct(&ti_arr);
         slang_assembly_typeinfo_destruct(&ti_elem);
      }
      break;
   case slang_oper_call:
      {
         slang_function *fun;

         fun =
            _slang_locate_function(A->space.funcs, op->a_id, op->children,
                                   op->num_children, &A->space, A->atoms);
         if (fun == NULL) {
            if (!_slang_assemble_constructor(A, op))
               return GL_FALSE;
         }
         else {
            if (!_slang_assemble_function_call
                (A, fun, op->children, op->num_children, GL_FALSE))
               return GL_FALSE;
         }
         A->ref = slang_ref_forbid;
      }
      break;
   case slang_oper_field:
      {
         slang_assembly_typeinfo ti_after, ti_before;

         if (!slang_assembly_typeinfo_construct(&ti_after))
            return GL_FALSE;
         if (!slang_assembly_typeinfo_construct(&ti_before)) {
            slang_assembly_typeinfo_destruct(&ti_after);
            return GL_FALSE;
         }
         if (!handle_field(A, &ti_after, &ti_before, op, ref)) {
            slang_assembly_typeinfo_destruct(&ti_after);
            slang_assembly_typeinfo_destruct(&ti_before);
            return GL_FALSE;
         }
         slang_assembly_typeinfo_destruct(&ti_after);
         slang_assembly_typeinfo_destruct(&ti_before);
      }
      break;
   case slang_oper_postincrement:
      if (!assemble_function_call_name_dummyint(A, "++", op->children))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   case slang_oper_postdecrement:
      if (!assemble_function_call_name_dummyint(A, "--", op->children))
         return GL_FALSE;
      A->ref = slang_ref_forbid;
      break;
   default:
      return GL_FALSE;
   }

   return GL_TRUE;
}