aboutsummaryrefslogtreecommitdiffstats
path: root/code/qcommon/vm.c
blob: 82c08139474c8266112b82089d25cc0576b95ad0 (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
/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// vm.c -- virtual machine

/*


intermix code and data
symbol table

a dll has one imported function: VM_SystemCall
and one exported function: Perform


*/

#include "vm_local.h"


vm_t	*currentVM = NULL;
vm_t	*lastVM    = NULL;
int		vm_debugLevel;

// used by Com_Error to get rid of running vm's before longjmp
static int forced_unload;

#define	MAX_VM		3
vm_t	vmTable[MAX_VM];


void VM_VmInfo_f( void );
void VM_VmProfile_f( void );



#if 0 // 64bit!
// converts a VM pointer to a C pointer and
// checks to make sure that the range is acceptable
void	*VM_VM2C( vmptr_t p, int length ) {
	return (void *)p;
}
#endif

void VM_Debug( int level ) {
	vm_debugLevel = level;
}

/*
==============
VM_Init
==============
*/
void VM_Init( void ) {
	Cvar_Get( "vm_cgame", "2", CVAR_ARCHIVE );	// !@# SHIP WITH SET TO 2
	Cvar_Get( "vm_game", "2", CVAR_ARCHIVE );	// !@# SHIP WITH SET TO 2
	Cvar_Get( "vm_ui", "2", CVAR_ARCHIVE );		// !@# SHIP WITH SET TO 2

	Cmd_AddCommand ("vmprofile", VM_VmProfile_f );
	Cmd_AddCommand ("vminfo", VM_VmInfo_f );

	Com_Memset( vmTable, 0, sizeof( vmTable ) );
}


/*
===============
VM_ValueToSymbol

Assumes a program counter value
===============
*/
const char *VM_ValueToSymbol( vm_t *vm, int value ) {
	vmSymbol_t	*sym;
	static char		text[MAX_TOKEN_CHARS];

	sym = vm->symbols;
	if ( !sym ) {
		return "NO SYMBOLS";
	}

	// find the symbol
	while ( sym->next && sym->next->symValue <= value ) {
		sym = sym->next;
	}

	if ( value == sym->symValue ) {
		return sym->symName;
	}

	Com_sprintf( text, sizeof( text ), "%s+%i", sym->symName, value - sym->symValue );

	return text;
}

/*
===============
VM_ValueToFunctionSymbol

For profiling, find the symbol behind this value
===============
*/
vmSymbol_t *VM_ValueToFunctionSymbol( vm_t *vm, int value ) {
	vmSymbol_t	*sym;
	static vmSymbol_t	nullSym;

	sym = vm->symbols;
	if ( !sym ) {
		return &nullSym;
	}

	while ( sym->next && sym->next->symValue <= value ) {
		sym = sym->next;
	}

	return sym;
}


/*
===============
VM_SymbolToValue
===============
*/
int VM_SymbolToValue( vm_t *vm, const char *symbol ) {
	vmSymbol_t	*sym;

	for ( sym = vm->symbols ; sym ; sym = sym->next ) {
		if ( !strcmp( symbol, sym->symName ) ) {
			return sym->symValue;
		}
	}
	return 0;
}


/*
=====================
VM_SymbolForCompiledPointer
=====================
*/
#if 0 // 64bit!
const char *VM_SymbolForCompiledPointer( vm_t *vm, void *code ) {
	int			i;

	if ( code < (void *)vm->codeBase ) {
		return "Before code block";
	}
	if ( code >= (void *)(vm->codeBase + vm->codeLength) ) {
		return "After code block";
	}

	// find which original instruction it is after
	for ( i = 0 ; i < vm->codeLength ; i++ ) {
		if ( (void *)vm->instructionPointers[i] > code ) {
			break;
		}
	}
	i--;

	// now look up the bytecode instruction pointer
	return VM_ValueToSymbol( vm, i );
}
#endif



/*
===============
ParseHex
===============
*/
int	ParseHex( const char *text ) {
	int		value;
	int		c;

	value = 0;
	while ( ( c = *text++ ) != 0 ) {
		if ( c >= '0' && c <= '9' ) {
			value = value * 16 + c - '0';
			continue;
		}
		if ( c >= 'a' && c <= 'f' ) {
			value = value * 16 + 10 + c - 'a';
			continue;
		}
		if ( c >= 'A' && c <= 'F' ) {
			value = value * 16 + 10 + c - 'A';
			continue;
		}
	}

	return value;
}

/*
===============
VM_LoadSymbols
===============
*/
void VM_LoadSymbols( vm_t *vm ) {
	int		len;
	union {
		char	*c;
		void	*v;
	} mapfile;
	char *text_p, *token;
	char	name[MAX_QPATH];
	char	symbols[MAX_QPATH];
	vmSymbol_t	**prev, *sym;
	int		count;
	int		value;
	int		chars;
	int		segment;
	int		numInstructions;

	// don't load symbols if not developer
	if ( !com_developer->integer ) {
		return;
	}

	COM_StripExtension(vm->name, name, sizeof(name));
	Com_sprintf( symbols, sizeof( symbols ), "vm/%s.map", name );
	len = FS_ReadFile( symbols, &mapfile.v );
	if ( !mapfile.c ) {
		Com_Printf( "Couldn't load symbol file: %s\n", symbols );
		return;
	}

	numInstructions = vm->instructionPointersLength >> 2;

	// parse the symbols
	text_p = mapfile.c;
	prev = &vm->symbols;
	count = 0;

	while ( 1 ) {
		token = COM_Parse( &text_p );
		if ( !token[0] ) {
			break;
		}
		segment = ParseHex( token );
		if ( segment ) {
			COM_Parse( &text_p );
			COM_Parse( &text_p );
			continue;		// only load code segment values
		}

		token = COM_Parse( &text_p );
		if ( !token[0] ) {
			Com_Printf( "WARNING: incomplete line at end of file\n" );
			break;
		}
		value = ParseHex( token );

		token = COM_Parse( &text_p );
		if ( !token[0] ) {
			Com_Printf( "WARNING: incomplete line at end of file\n" );
			break;
		}
		chars = strlen( token );
		sym = Hunk_Alloc( sizeof( *sym ) + chars, h_high );
		*prev = sym;
		prev = &sym->next;
		sym->next = NULL;

		// convert value from an instruction number to a code offset
		if ( value >= 0 && value < numInstructions ) {
			value = vm->instructionPointers[value];
		}

		sym->symValue = value;
		Q_strncpyz( sym->symName, token, chars + 1 );

		count++;
	}

	vm->numSymbols = count;
	Com_Printf( "%i symbols parsed from %s\n", count, symbols );
	FS_FreeFile( mapfile.v );
}

/*
============
VM_DllSyscall

Dlls will call this directly

 rcg010206 The horror; the horror.

  The syscall mechanism relies on stack manipulation to get it's args.
   This is likely due to C's inability to pass "..." parameters to
   a function in one clean chunk. On PowerPC Linux, these parameters
   are not necessarily passed on the stack, so while (&arg[0] == arg)
   is true, (&arg[1] == 2nd function parameter) is not necessarily
   accurate, as arg's value might have been stored to the stack or
   other piece of scratch memory to give it a valid address, but the
   next parameter might still be sitting in a register.

  Quake's syscall system also assumes that the stack grows downward,
   and that any needed types can be squeezed, safely, into a signed int.

  This hack below copies all needed values for an argument to a
   array in memory, so that Quake can get the correct values. This can
   also be used on systems where the stack grows upwards, as the
   presumably standard and safe stdargs.h macros are used.

  As for having enough space in a signed int for your datatypes, well,
   it might be better to wait for DOOM 3 before you start porting.  :)

  The original code, while probably still inherently dangerous, seems
   to work well enough for the platforms it already works on. Rather
   than add the performance hit for those platforms, the original code
   is still in use there.

  For speed, we just grab 15 arguments, and don't worry about exactly
   how many the syscall actually needs; the extra is thrown away.
 
============
*/
intptr_t QDECL VM_DllSyscall( intptr_t arg, ... ) {
#if !id386
  // rcg010206 - see commentary above
  intptr_t args[16];
  int i;
  va_list ap;
  
  args[0] = arg;
  
  va_start(ap, arg);
  for (i = 1; i < sizeof (args) / sizeof (args[i]); i++)
    args[i] = va_arg(ap, intptr_t);
  va_end(ap);
  
  return currentVM->systemCall( args );
#else // original id code
	return currentVM->systemCall( &arg );
#endif
}


#define	STACK_SIZE	0x20000

/*
=================
VM_LoadQVM

Load a .qvm file
=================
*/
vmHeader_t *VM_LoadQVM( vm_t *vm, qboolean alloc ) {
	int					length;
	int					dataLength;
	int					i;
	char				filename[MAX_QPATH];
	union {
		vmHeader_t	*h;
		void				*v;
	} header;

	// load the image
	Com_sprintf( filename, sizeof(filename), "vm/%s.qvm", vm->name );
	Com_Printf( "Loading vm file %s...\n", filename );
	length = FS_ReadFile( filename, &header.v );
	if ( !header.h ) {
		Com_Printf( "Failed.\n" );
		VM_Free( vm );
		return NULL;
	}

	if( LittleLong( header.h->vmMagic ) == VM_MAGIC_VER2 ) {
		Com_Printf( "...which has vmMagic VM_MAGIC_VER2\n" );

		// byte swap the header
		for ( i = 0 ; i < sizeof( vmHeader_t ) / 4 ; i++ ) {
			((int *)header.h)[i] = LittleLong( ((int *)header.h)[i] );
		}

		// validate
		if ( header.h->jtrgLength < 0
			|| header.h->bssLength < 0
			|| header.h->dataLength < 0
			|| header.h->litLength < 0
			|| header.h->codeLength <= 0 ) {
			VM_Free( vm );
			Com_Error( ERR_FATAL, "%s has bad header", filename );
		}
	} else if( LittleLong( header.h->vmMagic ) == VM_MAGIC ) {
		// byte swap the header
		// sizeof( vmHeader_t ) - sizeof( int ) is the 1.32b vm header size
		for ( i = 0 ; i < ( sizeof( vmHeader_t ) - sizeof( int ) ) / 4 ; i++ ) {
			((int *)header.h)[i] = LittleLong( ((int *)header.h)[i] );
		}

		// validate
		if ( header.h->bssLength < 0
			|| header.h->dataLength < 0
			|| header.h->litLength < 0
			|| header.h->codeLength <= 0 ) {
			VM_Free( vm );
			Com_Error( ERR_FATAL, "%s has bad header", filename );
		}
	} else {
		VM_Free( vm );
		Com_Error( ERR_FATAL, "%s does not have a recognisable "
				"magic number in its header", filename );
	}

	// round up to next power of 2 so all data operations can
	// be mask protected
	dataLength = header.h->dataLength + header.h->litLength +
		header.h->bssLength + STACK_SIZE;
	for ( i = 0 ; dataLength > ( 1 << i ) ; i++ ) {
	}
	dataLength = 1 << i;

	if( alloc ) {
		// allocate zero filled space for initialized and uninitialized data
		vm->dataBase = Hunk_Alloc( dataLength, h_high );
		vm->dataMask = dataLength - 1;
	} else {
		// clear the data
		Com_Memset( vm->dataBase, 0, dataLength );
	}

	// copy the intialized data
	Com_Memcpy( vm->dataBase, (byte *)header.h + header.h->dataOffset,
		header.h->dataLength + header.h->litLength );

	// byte swap the longs
	for ( i = 0 ; i < header.h->dataLength ; i += 4 ) {
		*(int *)(vm->dataBase + i) = LittleLong( *(int *)(vm->dataBase + i ) );
	}

	if( header.h->vmMagic == VM_MAGIC_VER2 ) {
		vm->numJumpTableTargets = header.h->jtrgLength >> 2;
		Com_Printf( "Loading %d jump table targets\n", vm->numJumpTableTargets );

		if( alloc ) {
			vm->jumpTableTargets = Hunk_Alloc( header.h->jtrgLength, h_high );
		} else {
			Com_Memset( vm->jumpTableTargets, 0, header.h->jtrgLength );
		}

		Com_Memcpy( vm->jumpTableTargets, (byte *)header.h + header.h->dataOffset +
				header.h->dataLength + header.h->litLength, header.h->jtrgLength );

		// byte swap the longs
		for ( i = 0 ; i < header.h->jtrgLength ; i += 4 ) {
			*(int *)(vm->jumpTableTargets + i) = LittleLong( *(int *)(vm->jumpTableTargets + i ) );
		}
	}

	return header.h;
}

/*
=================
VM_Restart

Reload the data, but leave everything else in place
This allows a server to do a map_restart without changing memory allocation
=================
*/
vm_t *VM_Restart( vm_t *vm ) {
	vmHeader_t	*header;

	// DLL's can't be restarted in place
	if ( vm->dllHandle ) {
		char	name[MAX_QPATH];
		intptr_t	(*systemCall)( intptr_t *parms );
		
		systemCall = vm->systemCall;	
		Q_strncpyz( name, vm->name, sizeof( name ) );

		VM_Free( vm );

		vm = VM_Create( name, systemCall, VMI_NATIVE );
		return vm;
	}

	// load the image
	Com_Printf( "VM_Restart()\n" );

	if( !( header = VM_LoadQVM( vm, qfalse ) ) ) {
		Com_Error( ERR_DROP, "VM_Restart failed.\n" );
		return NULL;
	}

	// free the original file
	FS_FreeFile( header );

	return vm;
}

/*
================
VM_Create

If image ends in .qvm it will be interpreted, otherwise
it will attempt to load as a system dll
================
*/
vm_t *VM_Create( const char *module, intptr_t (*systemCalls)(intptr_t *), 
				vmInterpret_t interpret ) {
	vm_t		*vm;
	vmHeader_t	*header;
	int			i, remaining;

	if ( !module || !module[0] || !systemCalls ) {
		Com_Error( ERR_FATAL, "VM_Create: bad parms" );
	}

	remaining = Hunk_MemoryRemaining();

	// see if we already have the VM
	for ( i = 0 ; i < MAX_VM ; i++ ) {
		if (!Q_stricmp(vmTable[i].name, module)) {
			vm = &vmTable[i];
			return vm;
		}
	}

	// find a free vm
	for ( i = 0 ; i < MAX_VM ; i++ ) {
		if ( !vmTable[i].name[0] ) {
			break;
		}
	}

	if ( i == MAX_VM ) {
		Com_Error( ERR_FATAL, "VM_Create: no free vm_t" );
	}

	vm = &vmTable[i];

	Q_strncpyz( vm->name, module, sizeof( vm->name ) );
	vm->systemCall = systemCalls;

	if ( interpret == VMI_NATIVE ) {
		// try to load as a system dll
		Com_Printf( "Loading dll file %s.\n", vm->name );
		vm->dllHandle = Sys_LoadDll( module, vm->fqpath , &vm->entryPoint, VM_DllSyscall );
		if ( vm->dllHandle ) {
			return vm;
		}

		Com_Printf( "Failed to load dll, looking for qvm.\n" );
		interpret = VMI_COMPILED;
	}

	// load the image
	if( !( header = VM_LoadQVM( vm, qtrue ) ) ) {
		return NULL;
	}

	// allocate space for the jump targets, which will be filled in by the compile/prep functions
	vm->instructionPointersLength = header->instructionCount * 4;
	vm->instructionPointers = Hunk_Alloc( vm->instructionPointersLength, h_high );

	// copy or compile the instructions
	vm->codeLength = header->codeLength;

	vm->compiled = qfalse;

#ifdef NO_VM_COMPILED
	if(interpret >= VMI_COMPILED) {
		Com_Printf("Architecture doesn't have a bytecode compiler, using interpreter\n");
		interpret = VMI_BYTECODE;
	}
#else
	if ( interpret >= VMI_COMPILED ) {
		vm->compiled = qtrue;
		VM_Compile( vm, header );
	}
#endif
	// VM_Compile may have reset vm->compiled if compilation failed
	if (!vm->compiled)
	{
		VM_PrepareInterpreter( vm, header );
	}

	// free the original file
	FS_FreeFile( header );

	// load the map file
	VM_LoadSymbols( vm );

	// the stack is implicitly at the end of the image
	vm->programStack = vm->dataMask + 1;
	vm->stackBottom = vm->programStack - STACK_SIZE;

	Com_Printf("%s loaded in %d bytes on the hunk\n", module, remaining - Hunk_MemoryRemaining());

	return vm;
}

/*
==============
VM_Free
==============
*/
void VM_Free( vm_t *vm ) {

	if(!vm) {
		return;
	}

	if(vm->callLevel) {
		if(!forced_unload) {
			Com_Error( ERR_FATAL, "VM_Free(%s) on running vm", vm->name );
			return;
		} else {
			Com_Printf( "forcefully unloading %s vm\n", vm->name );
		}
	}

	if(vm->destroy)
		vm->destroy(vm);

	if ( vm->dllHandle ) {
		Sys_UnloadDll( vm->dllHandle );
		Com_Memset( vm, 0, sizeof( *vm ) );
	}
#if 0	// now automatically freed by hunk
	if ( vm->codeBase ) {
		Z_Free( vm->codeBase );
	}
	if ( vm->dataBase ) {
		Z_Free( vm->dataBase );
	}
	if ( vm->instructionPointers ) {
		Z_Free( vm->instructionPointers );
	}
#endif
	Com_Memset( vm, 0, sizeof( *vm ) );

	currentVM = NULL;
	lastVM = NULL;
}

void VM_Clear(void) {
	int i;
	for (i=0;i<MAX_VM; i++) {
		VM_Free(&vmTable[i]);
	}
}

void VM_Forced_Unload_Start(void) {
	forced_unload = 1;
}

void VM_Forced_Unload_Done(void) {
	forced_unload = 0;
}

void *VM_ArgPtr( intptr_t intValue ) {
	if ( !intValue ) {
		return NULL;
	}
	// currentVM is missing on reconnect
	if ( currentVM==NULL )
	  return NULL;

	if ( currentVM->entryPoint ) {
		return (void *)(currentVM->dataBase + intValue);
	}
	else {
		return (void *)(currentVM->dataBase + (intValue & currentVM->dataMask));
	}
}

void *VM_ExplicitArgPtr( vm_t *vm, intptr_t intValue ) {
	if ( !intValue ) {
		return NULL;
	}

	// currentVM is missing on reconnect here as well?
	if ( currentVM==NULL )
	  return NULL;

	//
	if ( vm->entryPoint ) {
		return (void *)(vm->dataBase + intValue);
	}
	else {
		return (void *)(vm->dataBase + (intValue & vm->dataMask));
	}
}


/*
==============
VM_Call


Upon a system call, the stack will look like:

sp+32	parm1
sp+28	parm0
sp+24	return value
sp+20	return address
sp+16	local1
sp+14	local0
sp+12	arg1
sp+8	arg0
sp+4	return stack
sp		return address

An interpreted function will immediately execute
an OP_ENTER instruction, which will subtract space for
locals from sp
==============
*/
#define	MAX_STACK	256
#define	STACK_MASK	(MAX_STACK-1)

intptr_t	QDECL VM_Call( vm_t *vm, int callnum, ... ) {
	vm_t	*oldVM;
	intptr_t r;
	int i;

	if ( !vm ) {
		Com_Error( ERR_FATAL, "VM_Call with NULL vm" );
	}

	oldVM = currentVM;
	currentVM = vm;
	lastVM = vm;

	if ( vm_debugLevel ) {
	  Com_Printf( "VM_Call( %d )\n", callnum );
	}

	++vm->callLevel;
	// if we have a dll loaded, call it directly
	if ( vm->entryPoint ) {
		//rcg010207 -  see dissertation at top of VM_DllSyscall() in this file.
		int args[10];
		va_list ap;
		va_start(ap, callnum);
		for (i = 0; i < sizeof (args) / sizeof (args[i]); i++) {
			args[i] = va_arg(ap, int);
		}
		va_end(ap);

		r = vm->entryPoint( callnum,  args[0],  args[1],  args[2], args[3],
                            args[4],  args[5],  args[6], args[7],
                            args[8],  args[9]);
	} else {
#if id386 || idsparc // i386/sparc calling convention doesn't need conversion
#ifndef NO_VM_COMPILED
		if ( vm->compiled )
			r = VM_CallCompiled( vm, (int*)&callnum );
		else
#endif
			r = VM_CallInterpreted( vm, (int*)&callnum );
#else
		struct {
			int callnum;
			int args[10];
		} a;
		va_list ap;

		a.callnum = callnum;
		va_start(ap, callnum);
		for (i = 0; i < sizeof (a.args) / sizeof (a.args[0]); i++) {
			a.args[i] = va_arg(ap, int);
		}
		va_end(ap);
#ifndef NO_VM_COMPILED
		if ( vm->compiled )
			r = VM_CallCompiled( vm, &a.callnum );
		else
#endif
			r = VM_CallInterpreted( vm, &a.callnum );
#endif
	}
	--vm->callLevel;

	if ( oldVM != NULL )
	  currentVM = oldVM;
	return r;
}

//=================================================================

static int QDECL VM_ProfileSort( const void *a, const void *b ) {
	vmSymbol_t	*sa, *sb;

	sa = *(vmSymbol_t **)a;
	sb = *(vmSymbol_t **)b;

	if ( sa->profileCount < sb->profileCount ) {
		return -1;
	}
	if ( sa->profileCount > sb->profileCount ) {
		return 1;
	}
	return 0;
}

/*
==============
VM_VmProfile_f

==============
*/
void VM_VmProfile_f( void ) {
	vm_t		*vm;
	vmSymbol_t	**sorted, *sym;
	int			i;
	double		total;

	if ( !lastVM ) {
		return;
	}

	vm = lastVM;

	if ( !vm->numSymbols ) {
		return;
	}

	sorted = Z_Malloc( vm->numSymbols * sizeof( *sorted ) );
	sorted[0] = vm->symbols;
	total = sorted[0]->profileCount;
	for ( i = 1 ; i < vm->numSymbols ; i++ ) {
		sorted[i] = sorted[i-1]->next;
		total += sorted[i]->profileCount;
	}

	qsort( sorted, vm->numSymbols, sizeof( *sorted ), VM_ProfileSort );

	for ( i = 0 ; i < vm->numSymbols ; i++ ) {
		int		perc;

		sym = sorted[i];

		perc = 100 * (float) sym->profileCount / total;
		Com_Printf( "%2i%% %9i %s\n", perc, sym->profileCount, sym->symName );
		sym->profileCount = 0;
	}

	Com_Printf("    %9.0f total\n", total );

	Z_Free( sorted );
}

/*
==============
VM_VmInfo_f

==============
*/
void VM_VmInfo_f( void ) {
	vm_t	*vm;
	int		i;

	Com_Printf( "Registered virtual machines:\n" );
	for ( i = 0 ; i < MAX_VM ; i++ ) {
		vm = &vmTable[i];
		if ( !vm->name[0] ) {
			break;
		}
		Com_Printf( "%s : ", vm->name );
		if ( vm->dllHandle ) {
			Com_Printf( "native\n" );
			continue;
		}
		if ( vm->compiled ) {
			Com_Printf( "compiled on load\n" );
		} else {
			Com_Printf( "interpreted\n" );
		}
		Com_Printf( "    code length : %7i\n", vm->codeLength );
		Com_Printf( "    table length: %7i\n", vm->instructionPointersLength );
		Com_Printf( "    data length : %7i\n", vm->dataMask + 1 );
	}
}

/*
===============
VM_LogSyscalls

Insert calls to this while debugging the vm compiler
===============
*/
void VM_LogSyscalls( int *args ) {
	static	int		callnum;
	static	FILE	*f;

	if ( !f ) {
		f = fopen("syscalls.log", "w" );
	}
	callnum++;
	fprintf(f, "%i: %p (%i) = %i %i %i %i\n", callnum, (void*)(args - (int *)currentVM->dataBase),
		args[0], args[1], args[2], args[3], args[4] );
}