xref: /illumos-gate/usr/src/common/ficl/vm.c (revision a536a2a3182b56eef2630fb4b4509c9e106655e6)
1 /*
2  * v m . c
3  * Forth Inspired Command Language - virtual machine methods
4  * Author: John Sadler (john_sadler@alum.mit.edu)
5  * Created: 19 July 1997
6  * $Id: vm.c,v 1.17 2010/09/13 18:43:04 asau Exp $
7  */
8 /*
9  * This file implements the virtual machine of Ficl. Each virtual
10  * machine retains the state of an interpreter. A virtual machine
11  * owns a pair of stacks for parameters and return addresses, as
12  * well as a pile of state variables and the two dedicated registers
13  * of the interpreter.
14  */
15 /*
16  * Copyright (c) 1997-2001 John Sadler (john_sadler@alum.mit.edu)
17  * All rights reserved.
18  *
19  * Get the latest Ficl release at http://ficl.sourceforge.net
20  *
21  * I am interested in hearing from anyone who uses Ficl. If you have
22  * a problem, a success story, a defect, an enhancement request, or
23  * if you would like to contribute to the Ficl release, please
24  * contact me by email at the address above.
25  *
26  * L I C E N S E  and  D I S C L A I M E R
27  *
28  * Redistribution and use in source and binary forms, with or without
29  * modification, are permitted provided that the following conditions
30  * are met:
31  * 1. Redistributions of source code must retain the above copyright
32  *    notice, this list of conditions and the following disclaimer.
33  * 2. Redistributions in binary form must reproduce the above copyright
34  *    notice, this list of conditions and the following disclaimer in the
35  *    documentation and/or other materials provided with the distribution.
36  *
37  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
38  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
40  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
41  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
42  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
43  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
45  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
46  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  * SUCH DAMAGE.
48  */
49 
50 #include "ficl.h"
51 
52 #if FICL_ROBUST >= 2
53 #define	FICL_VM_CHECK(vm)	\
54 	FICL_VM_ASSERT(vm, (*(vm->ip - 1)) == vm->runningWord)
55 #else
56 #define	FICL_VM_CHECK(vm)
57 #endif
58 
59 /*
60  * v m B r a n c h R e l a t i v e
61  */
62 void
63 ficlVmBranchRelative(ficlVm *vm, int offset)
64 {
65 	vm->ip += offset;
66 }
67 
68 /*
69  * v m C r e a t e
70  * Creates a virtual machine either from scratch (if vm is NULL on entry)
71  * or by resizing and reinitializing an existing VM to the specified stack
72  * sizes.
73  */
74 ficlVm *
75 ficlVmCreate(ficlVm *vm, unsigned nPStack, unsigned nRStack)
76 {
77 	if (vm == NULL) {
78 		vm = (ficlVm *)ficlMalloc(sizeof (ficlVm));
79 		FICL_ASSERT(NULL, vm);
80 		memset(vm, 0, sizeof (ficlVm));
81 	}
82 
83 	if (vm->dataStack)
84 		ficlStackDestroy(vm->dataStack);
85 	vm->dataStack = ficlStackCreate(vm, "data", nPStack);
86 
87 	if (vm->returnStack)
88 		ficlStackDestroy(vm->returnStack);
89 	vm->returnStack = ficlStackCreate(vm, "return", nRStack);
90 
91 #if FICL_WANT_FLOAT
92 	if (vm->floatStack)
93 		ficlStackDestroy(vm->floatStack);
94 	vm->floatStack = ficlStackCreate(vm, "float", nPStack);
95 #endif
96 
97 	ficlVmReset(vm);
98 	return (vm);
99 }
100 
101 /*
102  * v m D e l e t e
103  * Free all memory allocated to the specified VM and its subordinate
104  * structures.
105  */
106 void
107 ficlVmDestroy(ficlVm *vm)
108 {
109 	if (vm) {
110 		ficlFree(vm->dataStack);
111 		ficlFree(vm->returnStack);
112 #if FICL_WANT_FLOAT
113 		ficlFree(vm->floatStack);
114 #endif
115 		ficlFree(vm);
116 	}
117 }
118 
119 /*
120  * v m E x e c u t e
121  * Sets up the specified word to be run by the inner interpreter.
122  * Executes the word's code part immediately, but in the case of
123  * colon definition, the definition itself needs the inner interpreter
124  * to complete. This does not happen until control reaches ficlExec
125  */
126 void
127 ficlVmExecuteWord(ficlVm *vm, ficlWord *pWord)
128 {
129 	ficlVmInnerLoop(vm, pWord);
130 }
131 
132 static void
133 ficlVmOptimizeJumpToJump(ficlVm *vm, ficlIp ip)
134 {
135 	ficlIp destination;
136 	switch ((ficlInstruction)(*ip)) {
137 	case ficlInstructionBranchParenWithCheck:
138 		*ip = (ficlWord *)ficlInstructionBranchParen;
139 		goto RUNTIME_FIXUP;
140 
141 	case ficlInstructionBranch0ParenWithCheck:
142 		*ip = (ficlWord *)ficlInstructionBranch0Paren;
143 RUNTIME_FIXUP:
144 		ip++;
145 		destination = ip + *(ficlInteger *)ip;
146 		switch ((ficlInstruction)*destination) {
147 		case ficlInstructionBranchParenWithCheck:
148 			/* preoptimize where we're jumping to */
149 			ficlVmOptimizeJumpToJump(vm, destination);
150 		case ficlInstructionBranchParen:
151 			destination++;
152 			destination += *(ficlInteger *)destination;
153 			*ip = (ficlWord *)(destination - ip);
154 		break;
155 		}
156 	}
157 }
158 
159 /*
160  * v m I n n e r L o o p
161  * the mysterious inner interpreter...
162  * This loop is the address interpreter that makes colon definitions
163  * work. Upon entry, it assumes that the IP points to an entry in
164  * a definition (the body of a colon word). It runs one word at a time
165  * until something does vmThrow. The catcher for this is expected to exist
166  * in the calling code.
167  * vmThrow gets you out of this loop with a longjmp()
168  */
169 
170 #if FICL_ROBUST <= 1
171 	/* turn off stack checking for primitives */
172 #define	_CHECK_STACK(stack, top, pop, push)
173 #else
174 
175 #define	_CHECK_STACK(stack, top, pop, push)	\
176 	ficlStackCheckNospill(stack, top, pop, push)
177 
178 FICL_PLATFORM_INLINE void
179 ficlStackCheckNospill(ficlStack *stack, ficlCell *top, int popCells,
180     int pushCells)
181 {
182 	/*
183 	 * Why save and restore stack->top?
184 	 * So the simple act of stack checking doesn't force a "register" spill,
185 	 * which might mask bugs (places where we needed to spill but didn't).
186 	 * --lch
187 	 */
188 	ficlCell *oldTop = stack->top;
189 	stack->top = top;
190 	ficlStackCheck(stack, popCells, pushCells);
191 	stack->top = oldTop;
192 }
193 
194 #endif /* FICL_ROBUST <= 1 */
195 
196 #define	CHECK_STACK(pop, push)		\
197 	_CHECK_STACK(vm->dataStack, dataTop, pop, push)
198 #define	CHECK_FLOAT_STACK(pop, push)	\
199 	_CHECK_STACK(vm->floatStack, floatTop, pop, push)
200 #define	CHECK_RETURN_STACK(pop, push)	\
201 	_CHECK_STACK(vm->returnStack, returnTop, pop, push)
202 
203 #if FICL_WANT_FLOAT
204 #define	FLOAT_LOCAL_VARIABLE_SPILL	\
205 	vm->floatStack->top = floatTop;
206 #define	FLOAT_LOCAL_VARIABLE_REFILL	\
207 	floatTop = vm->floatStack->top;
208 #else
209 #define	FLOAT_LOCAL_VARIABLE_SPILL
210 #define	FLOAT_LOCAL_VARIABLE_REFILL
211 #endif  /* FICL_WANT_FLOAT */
212 
213 #if FICL_WANT_LOCALS
214 #define	LOCALS_LOCAL_VARIABLE_SPILL	\
215 	vm->returnStack->frame = frame;
216 #define	LOCALS_LOCAL_VARIABLE_REFILL \
217 	frame = vm->returnStack->frame;
218 #else
219 #define	LOCALS_LOCAL_VARIABLE_SPILL
220 #define	LOCALS_LOCAL_VARIABLE_REFILL
221 #endif  /* FICL_WANT_FLOAT */
222 
223 #define	LOCAL_VARIABLE_SPILL	\
224 		vm->ip = (ficlIp)ip;	\
225 		vm->dataStack->top = dataTop;	\
226 		vm->returnStack->top = returnTop;	\
227 		FLOAT_LOCAL_VARIABLE_SPILL \
228 		LOCALS_LOCAL_VARIABLE_SPILL
229 
230 #define	LOCAL_VARIABLE_REFILL	\
231 		ip = (ficlInstruction *)vm->ip; \
232 		dataTop = vm->dataStack->top;	\
233 		returnTop = vm->returnStack->top;	\
234 		FLOAT_LOCAL_VARIABLE_REFILL	\
235 		LOCALS_LOCAL_VARIABLE_REFILL
236 
237 void
238 ficlVmInnerLoop(ficlVm *vm, ficlWord *fw)
239 {
240 	register ficlInstruction *ip;
241 	register ficlCell *dataTop;
242 	register ficlCell *returnTop;
243 #if FICL_WANT_FLOAT
244 	register ficlCell *floatTop;
245 	ficlFloat f;
246 #endif  /* FICL_WANT_FLOAT */
247 #if FICL_WANT_LOCALS
248 	register ficlCell *frame;
249 #endif  /* FICL_WANT_LOCALS */
250 	jmp_buf *oldExceptionHandler;
251 	jmp_buf exceptionHandler;
252 	int except;
253 	int once;
254 	int count;
255 	ficlInstruction instruction;
256 	ficlInteger i;
257 	ficlUnsigned u;
258 	ficlCell c;
259 	ficlCountedString *s;
260 	ficlCell *cell;
261 	char *cp;
262 
263 	once = (fw != NULL);
264 	if (once)
265 		count = 1;
266 
267 	oldExceptionHandler = vm->exceptionHandler;
268 	/* This has to come before the setjmp! */
269 	vm->exceptionHandler = &exceptionHandler;
270 	except = setjmp(exceptionHandler);
271 
272 	LOCAL_VARIABLE_REFILL;
273 
274 	if (except) {
275 		LOCAL_VARIABLE_SPILL;
276 		vm->exceptionHandler = oldExceptionHandler;
277 		ficlVmThrow(vm, except);
278 	}
279 
280 	for (;;) {
281 		if (once) {
282 			if (!count--)
283 				break;
284 			instruction = (ficlInstruction)((void *)fw);
285 		} else {
286 			instruction = *ip++;
287 			fw = (ficlWord *)instruction;
288 		}
289 
290 AGAIN:
291 		switch (instruction) {
292 		case ficlInstructionInvalid:
293 			ficlVmThrowError(vm,
294 			    "Error: NULL instruction executed!");
295 		return;
296 
297 		case ficlInstruction1:
298 		case ficlInstruction2:
299 		case ficlInstruction3:
300 		case ficlInstruction4:
301 		case ficlInstruction5:
302 		case ficlInstruction6:
303 		case ficlInstruction7:
304 		case ficlInstruction8:
305 		case ficlInstruction9:
306 		case ficlInstruction10:
307 		case ficlInstruction11:
308 		case ficlInstruction12:
309 		case ficlInstruction13:
310 		case ficlInstruction14:
311 		case ficlInstruction15:
312 		case ficlInstruction16:
313 			CHECK_STACK(0, 1);
314 			(++dataTop)->i = instruction;
315 		continue;
316 
317 		case ficlInstruction0:
318 		case ficlInstructionNeg1:
319 		case ficlInstructionNeg2:
320 		case ficlInstructionNeg3:
321 		case ficlInstructionNeg4:
322 		case ficlInstructionNeg5:
323 		case ficlInstructionNeg6:
324 		case ficlInstructionNeg7:
325 		case ficlInstructionNeg8:
326 		case ficlInstructionNeg9:
327 		case ficlInstructionNeg10:
328 		case ficlInstructionNeg11:
329 		case ficlInstructionNeg12:
330 		case ficlInstructionNeg13:
331 		case ficlInstructionNeg14:
332 		case ficlInstructionNeg15:
333 		case ficlInstructionNeg16:
334 			CHECK_STACK(0, 1);
335 			(++dataTop)->i = ficlInstruction0 - instruction;
336 		continue;
337 
338 		/*
339 		 * stringlit: Fetch the count from the dictionary, then push
340 		 * the address and count on the stack. Finally, update ip to
341 		 * point to the first aligned address after the string text.
342 		 */
343 		case ficlInstructionStringLiteralParen: {
344 			ficlUnsigned8 length;
345 			CHECK_STACK(0, 2);
346 
347 			s = (ficlCountedString *)(ip);
348 			length = s->length;
349 			cp = s->text;
350 			(++dataTop)->p = cp;
351 			(++dataTop)->i = length;
352 
353 			cp += length + 1;
354 			cp = ficlAlignPointer(cp);
355 			ip = (void *)cp;
356 		continue;
357 		}
358 
359 		case ficlInstructionCStringLiteralParen:
360 			CHECK_STACK(0, 1);
361 
362 			s = (ficlCountedString *)(ip);
363 			cp = s->text + s->length + 1;
364 			cp = ficlAlignPointer(cp);
365 			ip = (void *)cp;
366 			(++dataTop)->p = s;
367 		continue;
368 
369 #if FICL_WANT_OPTIMIZE == FICL_OPTIMIZE_FOR_SIZE
370 #if FICL_WANT_FLOAT
371 FLOAT_PUSH_CELL_POINTER_DOUBLE_MINIPROC:
372 			*++floatTop = cell[1];
373 			/* intentional fall-through */
374 FLOAT_PUSH_CELL_POINTER_MINIPROC:
375 			*++floatTop = cell[0];
376 		continue;
377 
378 FLOAT_POP_CELL_POINTER_MINIPROC:
379 			cell[0] = *floatTop--;
380 		continue;
381 
382 FLOAT_POP_CELL_POINTER_DOUBLE_MINIPROC:
383 			cell[0] = *floatTop--;
384 			cell[1] = *floatTop--;
385 		continue;
386 
387 #define	FLOAT_PUSH_CELL_POINTER_DOUBLE(cp)	\
388 	cell = (cp); goto FLOAT_PUSH_CELL_POINTER_DOUBLE_MINIPROC
389 #define	FLOAT_PUSH_CELL_POINTER(cp)		\
390 	cell = (cp); goto FLOAT_PUSH_CELL_POINTER_MINIPROC
391 #define	FLOAT_POP_CELL_POINTER_DOUBLE(cp)	\
392 	cell = (cp); goto FLOAT_POP_CELL_POINTER_DOUBLE_MINIPROC
393 #define	FLOAT_POP_CELL_POINTER(cp)		\
394 	cell = (cp); goto FLOAT_POP_CELL_POINTER_MINIPROC
395 #endif /* FICL_WANT_FLOAT */
396 
397 		/*
398 		 * Think of these as little mini-procedures.
399 		 * --lch
400 		 */
401 PUSH_CELL_POINTER_DOUBLE_MINIPROC:
402 			*++dataTop = cell[1];
403 			/* intentional fall-through */
404 PUSH_CELL_POINTER_MINIPROC:
405 			*++dataTop = cell[0];
406 		continue;
407 
408 POP_CELL_POINTER_MINIPROC:
409 			cell[0] = *dataTop--;
410 		continue;
411 POP_CELL_POINTER_DOUBLE_MINIPROC:
412 			cell[0] = *dataTop--;
413 			cell[1] = *dataTop--;
414 		continue;
415 
416 #define	PUSH_CELL_POINTER_DOUBLE(cp)	\
417 	cell = (cp); goto PUSH_CELL_POINTER_DOUBLE_MINIPROC
418 #define	PUSH_CELL_POINTER(cp)		\
419 	cell = (cp); goto PUSH_CELL_POINTER_MINIPROC
420 #define	POP_CELL_POINTER_DOUBLE(cp)	\
421 	cell = (cp); goto POP_CELL_POINTER_DOUBLE_MINIPROC
422 #define	POP_CELL_POINTER(cp)		\
423 	cell = (cp); goto POP_CELL_POINTER_MINIPROC
424 
425 BRANCH_MINIPROC:
426 			ip += *(ficlInteger *)ip;
427 		continue;
428 
429 #define	BRANCH()	goto BRANCH_MINIPROC
430 
431 EXIT_FUNCTION_MINIPROC:
432 			ip = (ficlInstruction *)((returnTop--)->p);
433 				continue;
434 
435 #define	EXIT_FUNCTION	goto EXIT_FUNCTION_MINIPROC
436 
437 #else /* FICL_WANT_SIZE */
438 
439 #if FICL_WANT_FLOAT
440 #define	FLOAT_PUSH_CELL_POINTER_DOUBLE(cp)	\
441 	cell = (cp); *++floatTop = cell[1]; *++floatTop = *cell; continue
442 #define	FLOAT_PUSH_CELL_POINTER(cp)		\
443 	cell = (cp); *++floatTop = *cell; continue
444 #define	FLOAT_POP_CELL_POINTER_DOUBLE(cp)	\
445 	cell = (cp); *cell = *floatTop--; cell[1] = *floatTop--; continue
446 #define	FLOAT_POP_CELL_POINTER(cp)		\
447 	cell = (cp); *cell = *floatTop--; continue
448 #endif /* FICL_WANT_FLOAT */
449 
450 #define	PUSH_CELL_POINTER_DOUBLE(cp)	\
451 	cell = (cp); *++dataTop = cell[1]; *++dataTop = *cell; continue
452 #define	PUSH_CELL_POINTER(cp)		\
453 	cell = (cp); *++dataTop = *cell; continue
454 #define	POP_CELL_POINTER_DOUBLE(cp)	\
455 	cell = (cp); *cell = *dataTop--; cell[1] = *dataTop--; continue
456 #define	POP_CELL_POINTER(cp)		\
457 	cell = (cp); *cell = *dataTop--; continue
458 
459 #define	BRANCH()	ip += *(ficlInteger *)ip; continue
460 #define	EXIT_FUNCTION()	ip = (ficlInstruction *)((returnTop--)->p); continue
461 
462 #endif /* FICL_WANT_SIZE */
463 
464 
465 		/*
466 		 * This is the runtime for (literal). It assumes that it is
467 		 * part of a colon definition, and that the next ficlCell
468 		 * contains a value to be pushed on the parameter stack at
469 		 * runtime. This code is compiled by "literal".
470 		 */
471 
472 		case ficlInstructionLiteralParen:
473 			CHECK_STACK(0, 1);
474 			(++dataTop)->i = *ip++;
475 		continue;
476 
477 		case ficlInstruction2LiteralParen:
478 			CHECK_STACK(0, 2);
479 			(++dataTop)->i = ip[1];
480 			(++dataTop)->i = ip[0];
481 			ip += 2;
482 		continue;
483 
484 #if FICL_WANT_LOCALS
485 		/*
486 		 * Link a frame on the return stack, reserving nCells of space
487 		 * for locals - the value of nCells is the next ficlCell in
488 		 * the instruction stream.
489 		 * 1) Push frame onto returnTop
490 		 * 2) frame = returnTop
491 		 * 3) returnTop += nCells
492 		 */
493 		case ficlInstructionLinkParen: {
494 			ficlInteger nCells = *ip++;
495 			(++returnTop)->p = frame;
496 			frame = returnTop + 1;
497 			returnTop += nCells;
498 		continue;
499 		}
500 
501 		/*
502 		 * Unink a stack frame previously created by stackLink
503 		 * 1) dataTop = frame
504 		 * 2) frame = pop()
505 		 */
506 		case ficlInstructionUnlinkParen:
507 			returnTop = frame - 1;
508 			frame = (returnTop--)->p;
509 		continue;
510 
511 		/*
512 		 * Immediate - cfa of a local while compiling - when executed,
513 		 * compiles code to fetch the value of a local given the
514 		 * local's index in the word's pfa
515 		 */
516 #if FICL_WANT_FLOAT
517 		case ficlInstructionGetF2LocalParen:
518 			FLOAT_PUSH_CELL_POINTER_DOUBLE(frame + *ip++);
519 
520 		case ficlInstructionGetFLocalParen:
521 			FLOAT_PUSH_CELL_POINTER(frame + *ip++);
522 
523 		case ficlInstructionToF2LocalParen:
524 			FLOAT_POP_CELL_POINTER_DOUBLE(frame + *ip++);
525 
526 		case ficlInstructionToFLocalParen:
527 			FLOAT_POP_CELL_POINTER(frame + *ip++);
528 #endif /* FICL_WANT_FLOAT */
529 
530 		case ficlInstructionGet2LocalParen:
531 			PUSH_CELL_POINTER_DOUBLE(frame + *ip++);
532 
533 		case ficlInstructionGetLocalParen:
534 			PUSH_CELL_POINTER(frame + *ip++);
535 
536 		/*
537 		 * Immediate - cfa of a local while compiling - when executed,
538 		 * compiles code to store the value of a local given the
539 		 * local's index in the word's pfa
540 		 */
541 
542 		case ficlInstructionTo2LocalParen:
543 			POP_CELL_POINTER_DOUBLE(frame + *ip++);
544 
545 		case ficlInstructionToLocalParen:
546 			POP_CELL_POINTER(frame + *ip++);
547 
548 		/*
549 		 * Silly little minor optimizations.
550 		 * --lch
551 		 */
552 		case ficlInstructionGetLocal0:
553 			PUSH_CELL_POINTER(frame);
554 
555 		case ficlInstructionGetLocal1:
556 			PUSH_CELL_POINTER(frame + 1);
557 
558 		case ficlInstructionGet2Local0:
559 			PUSH_CELL_POINTER_DOUBLE(frame);
560 
561 		case ficlInstructionToLocal0:
562 			POP_CELL_POINTER(frame);
563 
564 		case ficlInstructionToLocal1:
565 			POP_CELL_POINTER(frame + 1);
566 
567 		case ficlInstructionTo2Local0:
568 			POP_CELL_POINTER_DOUBLE(frame);
569 
570 #endif /* FICL_WANT_LOCALS */
571 
572 		case ficlInstructionPlus:
573 			CHECK_STACK(2, 1);
574 			i = (dataTop--)->i;
575 			dataTop->i += i;
576 		continue;
577 
578 		case ficlInstructionMinus:
579 			CHECK_STACK(2, 1);
580 			i = (dataTop--)->i;
581 			dataTop->i -= i;
582 		continue;
583 
584 		case ficlInstruction1Plus:
585 			CHECK_STACK(1, 1);
586 			dataTop->i++;
587 		continue;
588 
589 		case ficlInstruction1Minus:
590 			CHECK_STACK(1, 1);
591 			dataTop->i--;
592 		continue;
593 
594 		case ficlInstruction2Plus:
595 			CHECK_STACK(1, 1);
596 			dataTop->i += 2;
597 		continue;
598 
599 		case ficlInstruction2Minus:
600 			CHECK_STACK(1, 1);
601 			dataTop->i -= 2;
602 		continue;
603 
604 		case ficlInstructionDup: {
605 			ficlInteger i = dataTop->i;
606 			CHECK_STACK(0, 1);
607 			(++dataTop)->i = i;
608 			continue;
609 		}
610 
611 		case ficlInstructionQuestionDup:
612 			CHECK_STACK(1, 2);
613 
614 			if (dataTop->i != 0) {
615 				dataTop[1] = dataTop[0];
616 				dataTop++;
617 			}
618 
619 		continue;
620 
621 		case ficlInstructionSwap: {
622 			ficlCell swap;
623 			CHECK_STACK(2, 2);
624 			swap = dataTop[0];
625 			dataTop[0] = dataTop[-1];
626 			dataTop[-1] = swap;
627 		}
628 		continue;
629 
630 		case ficlInstructionDrop:
631 			CHECK_STACK(1, 0);
632 			dataTop--;
633 		continue;
634 
635 		case ficlInstruction2Drop:
636 			CHECK_STACK(2, 0);
637 			dataTop -= 2;
638 		continue;
639 
640 		case ficlInstruction2Dup:
641 			CHECK_STACK(2, 4);
642 			dataTop[1] = dataTop[-1];
643 			dataTop[2] = *dataTop;
644 			dataTop += 2;
645 		continue;
646 
647 		case ficlInstructionOver:
648 			CHECK_STACK(2, 3);
649 			dataTop[1] = dataTop[-1];
650 			dataTop++;
651 		continue;
652 
653 		case ficlInstruction2Over:
654 			CHECK_STACK(4, 6);
655 			dataTop[1] = dataTop[-3];
656 			dataTop[2] = dataTop[-2];
657 			dataTop += 2;
658 		continue;
659 
660 		case ficlInstructionPick:
661 			CHECK_STACK(1, 0);
662 			i = dataTop->i;
663 			if (i < 0)
664 				continue;
665 			CHECK_STACK(i + 2, i + 3);
666 			*dataTop = dataTop[-i - 1];
667 		continue;
668 
669 		/*
670 		 * Do stack rot.
671 		 * rot ( 1 2 3  -- 2 3 1 )
672 		 */
673 		case ficlInstructionRot:
674 			i = 2;
675 		goto ROLL;
676 
677 		/*
678 		 * Do stack roll.
679 		 * roll ( n -- )
680 		 */
681 		case ficlInstructionRoll:
682 			CHECK_STACK(1, 0);
683 			i = (dataTop--)->i;
684 
685 			if (i < 1)
686 				continue;
687 
688 ROLL:
689 			CHECK_STACK(i+1, i+2);
690 			c = dataTop[-i];
691 			memmove(dataTop - i, dataTop - (i - 1),
692 			    i * sizeof (ficlCell));
693 			*dataTop = c;
694 		continue;
695 
696 		/*
697 		 * Do stack -rot.
698 		 * -rot ( 1 2 3  -- 3 1 2 )
699 		 */
700 		case ficlInstructionMinusRot:
701 			i = 2;
702 		goto MINUSROLL;
703 
704 		/*
705 		 * Do stack -roll.
706 		 * -roll ( n -- )
707 		 */
708 		case ficlInstructionMinusRoll:
709 			CHECK_STACK(1, 0);
710 			i = (dataTop--)->i;
711 
712 			if (i < 1)
713 				continue;
714 
715 MINUSROLL:
716 			CHECK_STACK(i+1, i+2);
717 			c = *dataTop;
718 			memmove(dataTop - (i - 1), dataTop - i,
719 			    i * sizeof (ficlCell));
720 			dataTop[-i] = c;
721 
722 		continue;
723 
724 		/*
725 		 * Do stack 2swap
726 		 * 2swap ( 1 2 3 4  -- 3 4 1 2 )
727 		 */
728 		case ficlInstruction2Swap: {
729 			ficlCell c2;
730 			CHECK_STACK(4, 4);
731 
732 			c = *dataTop;
733 			c2 = dataTop[-1];
734 
735 			*dataTop = dataTop[-2];
736 			dataTop[-1] = dataTop[-3];
737 
738 			dataTop[-2] = c;
739 			dataTop[-3] = c2;
740 		continue;
741 		}
742 
743 		case ficlInstructionPlusStore: {
744 			ficlCell *cell;
745 			CHECK_STACK(2, 0);
746 			cell = (ficlCell *)(dataTop--)->p;
747 			cell->i += (dataTop--)->i;
748 		continue;
749 		}
750 
751 		case ficlInstructionQuadFetch: {
752 			ficlUnsigned32 *integer32;
753 			CHECK_STACK(1, 1);
754 			integer32 = (ficlUnsigned32 *)dataTop->i;
755 			dataTop->u = (ficlUnsigned)*integer32;
756 		continue;
757 		}
758 
759 		case ficlInstructionQuadStore: {
760 			ficlUnsigned32 *integer32;
761 			CHECK_STACK(2, 0);
762 			integer32 = (ficlUnsigned32 *)(dataTop--)->p;
763 			*integer32 = (ficlUnsigned32)((dataTop--)->u);
764 		continue;
765 		}
766 
767 		case ficlInstructionWFetch: {
768 			ficlUnsigned16 *integer16;
769 			CHECK_STACK(1, 1);
770 			integer16 = (ficlUnsigned16 *)dataTop->p;
771 			dataTop->u = ((ficlUnsigned)*integer16);
772 		continue;
773 		}
774 
775 		case ficlInstructionWStore: {
776 			ficlUnsigned16 *integer16;
777 			CHECK_STACK(2, 0);
778 			integer16 = (ficlUnsigned16 *)(dataTop--)->p;
779 			*integer16 = (ficlUnsigned16)((dataTop--)->u);
780 		continue;
781 		}
782 
783 		case ficlInstructionCFetch: {
784 			ficlUnsigned8 *integer8;
785 			CHECK_STACK(1, 1);
786 			integer8 = (ficlUnsigned8 *)dataTop->p;
787 			dataTop->u = ((ficlUnsigned)*integer8);
788 		continue;
789 		}
790 
791 		case ficlInstructionCStore: {
792 			ficlUnsigned8 *integer8;
793 			CHECK_STACK(2, 0);
794 			integer8 = (ficlUnsigned8 *)(dataTop--)->p;
795 			*integer8 = (ficlUnsigned8)((dataTop--)->u);
796 		continue;
797 		}
798 
799 
800 		/*
801 		 * l o g i c   a n d   c o m p a r i s o n s
802 		 */
803 
804 		case ficlInstruction0Equals:
805 			CHECK_STACK(1, 1);
806 			dataTop->i = FICL_BOOL(dataTop->i == 0);
807 		continue;
808 
809 		case ficlInstruction0Less:
810 			CHECK_STACK(1, 1);
811 			dataTop->i = FICL_BOOL(dataTop->i < 0);
812 		continue;
813 
814 		case ficlInstruction0Greater:
815 			CHECK_STACK(1, 1);
816 			dataTop->i = FICL_BOOL(dataTop->i > 0);
817 		continue;
818 
819 		case ficlInstructionEquals:
820 			CHECK_STACK(2, 1);
821 			i = (dataTop--)->i;
822 			dataTop->i = FICL_BOOL(dataTop->i == i);
823 		continue;
824 
825 		case ficlInstructionLess:
826 			CHECK_STACK(2, 1);
827 			i = (dataTop--)->i;
828 			dataTop->i = FICL_BOOL(dataTop->i < i);
829 		continue;
830 
831 		case ficlInstructionULess:
832 			CHECK_STACK(2, 1);
833 			u = (dataTop--)->u;
834 			dataTop->i = FICL_BOOL(dataTop->u < u);
835 		continue;
836 
837 		case ficlInstructionAnd:
838 			CHECK_STACK(2, 1);
839 			i = (dataTop--)->i;
840 			dataTop->i = dataTop->i & i;
841 		continue;
842 
843 		case ficlInstructionOr:
844 			CHECK_STACK(2, 1);
845 			i = (dataTop--)->i;
846 			dataTop->i = dataTop->i | i;
847 		continue;
848 
849 		case ficlInstructionXor:
850 			CHECK_STACK(2, 1);
851 			i = (dataTop--)->i;
852 			dataTop->i = dataTop->i ^ i;
853 		continue;
854 
855 		case ficlInstructionInvert:
856 			CHECK_STACK(1, 1);
857 			dataTop->i = ~dataTop->i;
858 		continue;
859 
860 		/*
861 		 * r e t u r n   s t a c k
862 		 */
863 		case ficlInstructionToRStack:
864 			CHECK_STACK(1, 0);
865 			CHECK_RETURN_STACK(0, 1);
866 			*++returnTop = *dataTop--;
867 		continue;
868 
869 		case ficlInstructionFromRStack:
870 			CHECK_STACK(0, 1);
871 			CHECK_RETURN_STACK(1, 0);
872 			*++dataTop = *returnTop--;
873 		continue;
874 
875 		case ficlInstructionFetchRStack:
876 			CHECK_STACK(0, 1);
877 			CHECK_RETURN_STACK(1, 1);
878 			*++dataTop = *returnTop;
879 		continue;
880 
881 		case ficlInstruction2ToR:
882 			CHECK_STACK(2, 0);
883 			CHECK_RETURN_STACK(0, 2);
884 			*++returnTop = dataTop[-1];
885 			*++returnTop = dataTop[0];
886 			dataTop -= 2;
887 		continue;
888 
889 		case ficlInstruction2RFrom:
890 			CHECK_STACK(0, 2);
891 			CHECK_RETURN_STACK(2, 0);
892 			*++dataTop = returnTop[-1];
893 			*++dataTop = returnTop[0];
894 			returnTop -= 2;
895 		continue;
896 
897 		case ficlInstruction2RFetch:
898 			CHECK_STACK(0, 2);
899 			CHECK_RETURN_STACK(2, 2);
900 			*++dataTop = returnTop[-1];
901 			*++dataTop = returnTop[0];
902 		continue;
903 
904 		/*
905 		 * f i l l
906 		 * CORE ( c-addr u char -- )
907 		 * If u is greater than zero, store char in each of u
908 		 * consecutive characters of memory beginning at c-addr.
909 		 */
910 		case ficlInstructionFill: {
911 			char c;
912 			char *memory;
913 			CHECK_STACK(3, 0);
914 			c = (char)(dataTop--)->i;
915 			u = (dataTop--)->u;
916 			memory = (char *)(dataTop--)->p;
917 
918 			/*
919 			 * memset() is faster than the previous hand-rolled
920 			 * solution.  --lch
921 			 */
922 			memset(memory, c, u);
923 		continue;
924 		}
925 
926 		/*
927 		 * l s h i f t
928 		 * l-shift CORE ( x1 u -- x2 )
929 		 * Perform a logical left shift of u bit-places on x1,
930 		 * giving x2. Put zeroes into the least significant bits
931 		 * vacated by the shift. An ambiguous condition exists if
932 		 * u is greater than or equal to the number of bits in a
933 		 * ficlCell.
934 		 *
935 		 * r-shift CORE ( x1 u -- x2 )
936 		 * Perform a logical right shift of u bit-places on x1,
937 		 * giving x2. Put zeroes into the most significant bits
938 		 * vacated by the shift. An ambiguous condition exists
939 		 * if u is greater than or equal to the number of bits
940 		 * in a ficlCell.
941 		 */
942 		case ficlInstructionLShift: {
943 			ficlUnsigned nBits;
944 			ficlUnsigned x1;
945 			CHECK_STACK(2, 1);
946 
947 			nBits = (dataTop--)->u;
948 			x1 = dataTop->u;
949 			dataTop->u = x1 << nBits;
950 		continue;
951 		}
952 
953 		case ficlInstructionRShift: {
954 			ficlUnsigned nBits;
955 			ficlUnsigned x1;
956 			CHECK_STACK(2, 1);
957 
958 			nBits = (dataTop--)->u;
959 			x1 = dataTop->u;
960 			dataTop->u = x1 >> nBits;
961 			continue;
962 		}
963 
964 		/*
965 		 * m a x   &   m i n
966 		 */
967 		case ficlInstructionMax: {
968 			ficlInteger n2;
969 			ficlInteger n1;
970 			CHECK_STACK(2, 1);
971 
972 			n2 = (dataTop--)->i;
973 			n1 = dataTop->i;
974 
975 			dataTop->i = ((n1 > n2) ? n1 : n2);
976 		continue;
977 		}
978 
979 		case ficlInstructionMin: {
980 			ficlInteger n2;
981 			ficlInteger n1;
982 			CHECK_STACK(2, 1);
983 
984 			n2 = (dataTop--)->i;
985 				n1 = dataTop->i;
986 
987 			dataTop->i = ((n1 < n2) ? n1 : n2);
988 			continue;
989 		}
990 
991 		/*
992 		 * m o v e
993 		 * CORE ( addr1 addr2 u -- )
994 		 * If u is greater than zero, copy the contents of u
995 		 * consecutive address units at addr1 to the u consecutive
996 		 * address units at addr2. After MOVE completes, the u
997 		 * consecutive address units at addr2 contain exactly
998 		 * what the u consecutive address units at addr1 contained
999 		 * before the move.
1000 		 * NOTE! This implementation assumes that a char is the same
1001 		 * size as an address unit.
1002 		 */
1003 		case ficlInstructionMove: {
1004 			ficlUnsigned u;
1005 			char *addr2;
1006 			char *addr1;
1007 			CHECK_STACK(3, 0);
1008 
1009 			u = (dataTop--)->u;
1010 			addr2 = (dataTop--)->p;
1011 			addr1 = (dataTop--)->p;
1012 
1013 			if (u == 0)
1014 				continue;
1015 			/*
1016 			 * Do the copy carefully, so as to be
1017 			 * correct even if the two ranges overlap
1018 			 */
1019 			/* Which ANSI C's memmove() does for you! Yay!  --lch */
1020 			memmove(addr2, addr1, u);
1021 		continue;
1022 		}
1023 
1024 		/*
1025 		 * s t o d
1026 		 * s-to-d CORE ( n -- d )
1027 		 * Convert the number n to the double-ficlCell number d with
1028 		 * the same numerical value.
1029 		 */
1030 		case ficlInstructionSToD: {
1031 			ficlInteger s;
1032 			CHECK_STACK(1, 2);
1033 
1034 			s = dataTop->i;
1035 
1036 			/* sign extend to 64 bits.. */
1037 			(++dataTop)->i = (s < 0) ? -1 : 0;
1038 		continue;
1039 		}
1040 
1041 		/*
1042 		 * c o m p a r e
1043 		 * STRING ( c-addr1 u1 c-addr2 u2 -- n )
1044 		 * Compare the string specified by c-addr1 u1 to the string
1045 		 * specified by c-addr2 u2. The strings are compared, beginning
1046 		 * at the given addresses, character by character, up to the
1047 		 * length of the shorter string or until a difference is found.
1048 		 * If the two strings are identical, n is zero. If the two
1049 		 * strings are identical up to the length of the shorter string,
1050 		 * n is minus-one (-1) if u1 is less than u2 and one (1)
1051 		 * otherwise. If the two strings are not identical up to the
1052 		 * length of the shorter string, n is minus-one (-1) if the
1053 		 * first non-matching character in the string specified by
1054 		 * c-addr1 u1 has a lesser numeric value than the corresponding
1055 		 * character in the string specified by c-addr2 u2 and
1056 		 * one (1) otherwise.
1057 		 */
1058 		case ficlInstructionCompare:
1059 			i = FICL_FALSE;
1060 		goto COMPARE;
1061 
1062 
1063 		case ficlInstructionCompareInsensitive:
1064 			i = FICL_TRUE;
1065 		goto COMPARE;
1066 
1067 COMPARE:
1068 		{
1069 			char *cp1, *cp2;
1070 			ficlUnsigned u1, u2, uMin;
1071 			int n = 0;
1072 
1073 			CHECK_STACK(4, 1);
1074 			u2  = (dataTop--)->u;
1075 			cp2 = (char *)(dataTop--)->p;
1076 			u1  = (dataTop--)->u;
1077 			cp1 = (char *)(dataTop--)->p;
1078 
1079 			uMin = (u1 < u2)? u1 : u2;
1080 			for (; (uMin > 0) && (n == 0); uMin--) {
1081 				int c1 = (unsigned char)*cp1++;
1082 				int c2 = (unsigned char)*cp2++;
1083 
1084 				if (i) {
1085 					c1 = tolower(c1);
1086 					c2 = tolower(c2);
1087 				}
1088 				n = (c1 - c2);
1089 			}
1090 
1091 			if (n == 0)
1092 				n = (int)(u1 - u2);
1093 
1094 			if (n < 0)
1095 				n = -1;
1096 			else if (n > 0)
1097 				n = 1;
1098 
1099 			(++dataTop)->i = n;
1100 		continue;
1101 		}
1102 
1103 		/*
1104 		 * r a n d o m
1105 		 * Ficl-specific
1106 		 */
1107 		case ficlInstructionRandom:
1108 			(++dataTop)->i = random();
1109 		continue;
1110 
1111 		/*
1112 		 * s e e d - r a n d o m
1113 		 * Ficl-specific
1114 		 */
1115 		case ficlInstructionSeedRandom:
1116 			srandom((dataTop--)->i);
1117 		continue;
1118 
1119 		case ficlInstructionGreaterThan: {
1120 			ficlInteger x, y;
1121 			CHECK_STACK(2, 1);
1122 			y = (dataTop--)->i;
1123 			x = dataTop->i;
1124 			dataTop->i = FICL_BOOL(x > y);
1125 		continue;
1126 
1127 		case ficlInstructionUGreaterThan:
1128 			CHECK_STACK(2, 1);
1129 			u = (dataTop--)->u;
1130 			dataTop->i = FICL_BOOL(dataTop->u > u);
1131 		continue;
1132 
1133 		}
1134 
1135 		/*
1136 		 * This function simply pops the previous instruction
1137 		 * pointer and returns to the "next" loop. Used for exiting
1138 		 * from within a definition. Note that exitParen is identical
1139 		 * to semiParen - they are in two different functions so that
1140 		 * "see" can correctly identify the end of a colon definition,
1141 		 * even if it uses "exit".
1142 		 */
1143 		case ficlInstructionExitParen:
1144 		case ficlInstructionSemiParen:
1145 			EXIT_FUNCTION();
1146 
1147 		/*
1148 		 * The first time we run "(branch)", perform a "peephole
1149 		 * optimization" to see if we're jumping to another
1150 		 * unconditional jump.  If so, just jump directly there.
1151 		 */
1152 		case ficlInstructionBranchParenWithCheck:
1153 			LOCAL_VARIABLE_SPILL;
1154 			ficlVmOptimizeJumpToJump(vm, vm->ip - 1);
1155 			LOCAL_VARIABLE_REFILL;
1156 		goto BRANCH_PAREN;
1157 
1158 		/*
1159 		 * Same deal with branch0.
1160 		 */
1161 		case ficlInstructionBranch0ParenWithCheck:
1162 			LOCAL_VARIABLE_SPILL;
1163 			ficlVmOptimizeJumpToJump(vm, vm->ip - 1);
1164 			LOCAL_VARIABLE_REFILL;
1165 			/* intentional fall-through */
1166 
1167 		/*
1168 		 * Runtime code for "(branch0)"; pop a flag from the stack,
1169 		 * branch if 0. fall through otherwise.
1170 		 * The heart of "if" and "until".
1171 		 */
1172 		case ficlInstructionBranch0Paren:
1173 			CHECK_STACK(1, 0);
1174 
1175 			if ((dataTop--)->i) {
1176 				/*
1177 				 * don't branch, but skip over branch
1178 				 * relative address
1179 				 */
1180 				ip += 1;
1181 				continue;
1182 			}
1183 			/* otherwise, take branch (to else/endif/begin) */
1184 			/* intentional fall-through! */
1185 
1186 		/*
1187 		 * Runtime for "(branch)" -- expects a literal offset in the
1188 		 * next compilation address, and branches to that location.
1189 		 */
1190 		case ficlInstructionBranchParen:
1191 BRANCH_PAREN:
1192 			BRANCH();
1193 
1194 		case ficlInstructionOfParen: {
1195 			ficlUnsigned a, b;
1196 
1197 			CHECK_STACK(2, 1);
1198 
1199 			a = (dataTop--)->u;
1200 			b = dataTop->u;
1201 
1202 			if (a == b) {
1203 				/* fall through */
1204 				ip++;
1205 				/* remove CASE argument */
1206 				dataTop--;
1207 			} else {
1208 				/* take branch to next of or endcase */
1209 				BRANCH();
1210 			}
1211 
1212 		continue;
1213 		}
1214 
1215 		case ficlInstructionDoParen: {
1216 			ficlCell index, limit;
1217 
1218 			CHECK_STACK(2, 0);
1219 
1220 			index = *dataTop--;
1221 			limit = *dataTop--;
1222 
1223 			/* copy "leave" target addr to stack */
1224 			(++returnTop)->i = *(ip++);
1225 			*++returnTop = limit;
1226 			*++returnTop = index;
1227 
1228 		continue;
1229 		}
1230 
1231 		case ficlInstructionQDoParen: {
1232 			ficlCell index, limit, leave;
1233 
1234 			CHECK_STACK(2, 0);
1235 
1236 			index = *dataTop--;
1237 			limit = *dataTop--;
1238 
1239 			leave.i = *ip;
1240 
1241 			if (limit.u == index.u) {
1242 				ip = leave.p;
1243 			} else {
1244 				ip++;
1245 				*++returnTop = leave;
1246 				*++returnTop = limit;
1247 				*++returnTop = index;
1248 			}
1249 
1250 		continue;
1251 		}
1252 
1253 		case ficlInstructionLoopParen:
1254 		case ficlInstructionPlusLoopParen: {
1255 			ficlInteger index;
1256 			ficlInteger limit;
1257 			int direction = 0;
1258 
1259 			index = returnTop->i;
1260 			limit = returnTop[-1].i;
1261 
1262 			if (instruction == ficlInstructionLoopParen)
1263 				index++;
1264 			else {
1265 				ficlInteger increment;
1266 				CHECK_STACK(1, 0);
1267 				increment = (dataTop--)->i;
1268 				index += increment;
1269 				direction = (increment < 0);
1270 			}
1271 
1272 			if (direction ^ (index >= limit)) {
1273 				/* nuke the loop indices & "leave" addr */
1274 				returnTop -= 3;
1275 				ip++;  /* fall through the loop */
1276 			} else {	/* update index, branch to loop head */
1277 				returnTop->i = index;
1278 				BRANCH();
1279 			}
1280 
1281 		continue;
1282 		}
1283 
1284 
1285 		/*
1286 		 * Runtime code to break out of a do..loop construct
1287 		 * Drop the loop control variables; the branch address
1288 		 * past "loop" is next on the return stack.
1289 		 */
1290 		case ficlInstructionLeave:
1291 			/* almost unloop */
1292 			returnTop -= 2;
1293 			/* exit */
1294 			EXIT_FUNCTION();
1295 
1296 		case ficlInstructionUnloop:
1297 			returnTop -= 3;
1298 		continue;
1299 
1300 		case ficlInstructionI:
1301 			*++dataTop = *returnTop;
1302 		continue;
1303 
1304 		case ficlInstructionJ:
1305 			*++dataTop = returnTop[-3];
1306 		continue;
1307 
1308 		case ficlInstructionK:
1309 			*++dataTop = returnTop[-6];
1310 		continue;
1311 
1312 		case ficlInstructionDoesParen: {
1313 			ficlDictionary *dictionary = ficlVmGetDictionary(vm);
1314 			dictionary->smudge->code =
1315 			    (ficlPrimitive)ficlInstructionDoDoes;
1316 			dictionary->smudge->param[0].p = ip;
1317 			ip = (ficlInstruction *)((returnTop--)->p);
1318 		continue;
1319 		}
1320 
1321 		case ficlInstructionDoDoes: {
1322 			ficlCell *cell;
1323 			ficlIp tempIP;
1324 
1325 			CHECK_STACK(0, 1);
1326 
1327 			cell = fw->param;
1328 			tempIP = (ficlIp)((*cell).p);
1329 			(++dataTop)->p = (cell + 1);
1330 			(++returnTop)->p = (void *)ip;
1331 			ip = (ficlInstruction *)tempIP;
1332 		continue;
1333 		}
1334 
1335 #if FICL_WANT_FLOAT
1336 		case ficlInstructionF2Fetch:
1337 			CHECK_FLOAT_STACK(0, 2);
1338 			CHECK_STACK(1, 0);
1339 			FLOAT_PUSH_CELL_POINTER_DOUBLE((dataTop--)->p);
1340 
1341 		case ficlInstructionFFetch:
1342 			CHECK_FLOAT_STACK(0, 1);
1343 			CHECK_STACK(1, 0);
1344 			FLOAT_PUSH_CELL_POINTER((dataTop--)->p);
1345 
1346 		case ficlInstructionF2Store:
1347 			CHECK_FLOAT_STACK(2, 0);
1348 			CHECK_STACK(1, 0);
1349 			FLOAT_POP_CELL_POINTER_DOUBLE((dataTop--)->p);
1350 
1351 		case ficlInstructionFStore:
1352 			CHECK_FLOAT_STACK(1, 0);
1353 			CHECK_STACK(1, 0);
1354 			FLOAT_POP_CELL_POINTER((dataTop--)->p);
1355 #endif /* FICL_WANT_FLOAT */
1356 
1357 		/*
1358 		 * two-fetch CORE ( a-addr -- x1 x2 )
1359 		 *
1360 		 * Fetch the ficlCell pair x1 x2 stored at a-addr.
1361 		 * x2 is stored at a-addr and x1 at the next consecutive
1362 		 * ficlCell. It is equivalent to the sequence
1363 		 * DUP ficlCell+ @ SWAP @ .
1364 		 */
1365 		case ficlInstruction2Fetch:
1366 			CHECK_STACK(1, 2);
1367 			PUSH_CELL_POINTER_DOUBLE((dataTop--)->p);
1368 
1369 		/*
1370 		 * fetch CORE ( a-addr -- x )
1371 		 *
1372 		 * x is the value stored at a-addr.
1373 		 */
1374 		case ficlInstructionFetch:
1375 			CHECK_STACK(1, 1);
1376 			PUSH_CELL_POINTER((dataTop--)->p);
1377 
1378 		/*
1379 		 * two-store    CORE ( x1 x2 a-addr -- )
1380 		 * Store the ficlCell pair x1 x2 at a-addr, with x2 at a-addr
1381 		 * and x1 at the next consecutive ficlCell. It is equivalent
1382 		 * to the sequence SWAP OVER ! ficlCell+ !
1383 		 */
1384 		case ficlInstruction2Store:
1385 			CHECK_STACK(3, 0);
1386 			POP_CELL_POINTER_DOUBLE((dataTop--)->p);
1387 
1388 		/*
1389 		 * store	CORE ( x a-addr -- )
1390 		 * Store x at a-addr.
1391 		 */
1392 		case ficlInstructionStore:
1393 			CHECK_STACK(2, 0);
1394 			POP_CELL_POINTER((dataTop--)->p);
1395 
1396 		case ficlInstructionComma: {
1397 			ficlDictionary *dictionary;
1398 			CHECK_STACK(1, 0);
1399 
1400 			dictionary = ficlVmGetDictionary(vm);
1401 			ficlDictionaryAppendCell(dictionary, *dataTop--);
1402 		continue;
1403 		}
1404 
1405 		case ficlInstructionCComma: {
1406 			ficlDictionary *dictionary;
1407 			char c;
1408 			CHECK_STACK(1, 0);
1409 
1410 			dictionary = ficlVmGetDictionary(vm);
1411 			c = (char)(dataTop--)->i;
1412 			ficlDictionaryAppendCharacter(dictionary, c);
1413 		continue;
1414 		}
1415 
1416 		case ficlInstructionCells:
1417 			CHECK_STACK(1, 1);
1418 			dataTop->i *= sizeof (ficlCell);
1419 		continue;
1420 
1421 		case ficlInstructionCellPlus:
1422 			CHECK_STACK(1, 1);
1423 			dataTop->i += sizeof (ficlCell);
1424 		continue;
1425 
1426 		case ficlInstructionStar:
1427 			CHECK_STACK(2, 1);
1428 			i = (dataTop--)->i;
1429 			dataTop->i *= i;
1430 		continue;
1431 
1432 		case ficlInstructionNegate:
1433 			CHECK_STACK(1, 1);
1434 			dataTop->i = - dataTop->i;
1435 		continue;
1436 
1437 		case ficlInstructionSlash:
1438 			CHECK_STACK(2, 1);
1439 			i = (dataTop--)->i;
1440 			dataTop->i /= i;
1441 		continue;
1442 
1443 		/*
1444 		 * slash-mod	CORE ( n1 n2 -- n3 n4 )
1445 		 * Divide n1 by n2, giving the single-ficlCell remainder n3
1446 		 * and the single-ficlCell quotient n4. An ambiguous condition
1447 		 * exists if n2 is zero. If n1 and n2 differ in sign, the
1448 		 * implementation-defined result returned will be the
1449 		 * same as that returned by either the phrase
1450 		 * >R S>D R> FM/MOD or the phrase >R S>D R> SM/REM.
1451 		 * NOTE: Ficl complies with the second phrase
1452 		 * (symmetric division)
1453 		 */
1454 		case ficlInstructionSlashMod: {
1455 			ficl2Integer n1;
1456 			ficlInteger n2;
1457 			ficl2IntegerQR qr;
1458 
1459 			CHECK_STACK(2, 2);
1460 			n2    = dataTop[0].i;
1461 			FICL_INTEGER_TO_2INTEGER(dataTop[-1].i, n1);
1462 
1463 			qr = ficl2IntegerDivideSymmetric(n1, n2);
1464 			dataTop[-1].i = qr.remainder;
1465 			dataTop[0].i = FICL_2UNSIGNED_GET_LOW(qr.quotient);
1466 		continue;
1467 		}
1468 
1469 		case ficlInstruction2Star:
1470 			CHECK_STACK(1, 1);
1471 			dataTop->i <<= 1;
1472 		continue;
1473 
1474 		case ficlInstruction2Slash:
1475 			CHECK_STACK(1, 1);
1476 			dataTop->i >>= 1;
1477 		continue;
1478 
1479 		case ficlInstructionStarSlash: {
1480 			ficlInteger x, y, z;
1481 			ficl2Integer prod;
1482 			CHECK_STACK(3, 1);
1483 
1484 			z = (dataTop--)->i;
1485 			y = (dataTop--)->i;
1486 			x = dataTop->i;
1487 
1488 			prod = ficl2IntegerMultiply(x, y);
1489 			dataTop->i = FICL_2UNSIGNED_GET_LOW(
1490 			    ficl2IntegerDivideSymmetric(prod, z).quotient);
1491 		continue;
1492 		}
1493 
1494 		case ficlInstructionStarSlashMod: {
1495 			ficlInteger x, y, z;
1496 			ficl2Integer prod;
1497 			ficl2IntegerQR qr;
1498 
1499 			CHECK_STACK(3, 2);
1500 
1501 			z = (dataTop--)->i;
1502 			y = dataTop[0].i;
1503 			x = dataTop[-1].i;
1504 
1505 			prod = ficl2IntegerMultiply(x, y);
1506 			qr   = ficl2IntegerDivideSymmetric(prod, z);
1507 
1508 			dataTop[-1].i = qr.remainder;
1509 			dataTop[0].i = FICL_2UNSIGNED_GET_LOW(qr.quotient);
1510 			continue;
1511 		}
1512 
1513 #if FICL_WANT_FLOAT
1514 		case ficlInstructionF0:
1515 			CHECK_FLOAT_STACK(0, 1);
1516 			(++floatTop)->f = 0.0f;
1517 		continue;
1518 
1519 		case ficlInstructionF1:
1520 			CHECK_FLOAT_STACK(0, 1);
1521 			(++floatTop)->f = 1.0f;
1522 		continue;
1523 
1524 		case ficlInstructionFNeg1:
1525 			CHECK_FLOAT_STACK(0, 1);
1526 			(++floatTop)->f = -1.0f;
1527 		continue;
1528 
1529 		/*
1530 		 * Floating point literal execution word.
1531 		 */
1532 		case ficlInstructionFLiteralParen:
1533 			CHECK_FLOAT_STACK(0, 1);
1534 
1535 			/*
1536 			 * Yes, I'm using ->i here,
1537 			 * but it's really a float.  --lch
1538 			 */
1539 			(++floatTop)->i = *ip++;
1540 				continue;
1541 
1542 		/*
1543 		 * Do float addition r1 + r2.
1544 		 * f+ ( r1 r2 -- r )
1545 		 */
1546 		case ficlInstructionFPlus:
1547 			CHECK_FLOAT_STACK(2, 1);
1548 
1549 			f = (floatTop--)->f;
1550 			floatTop->f += f;
1551 		continue;
1552 
1553 		/*
1554 		 * Do float subtraction r1 - r2.
1555 		 * f- ( r1 r2 -- r )
1556 		 */
1557 		case ficlInstructionFMinus:
1558 			CHECK_FLOAT_STACK(2, 1);
1559 
1560 			f = (floatTop--)->f;
1561 			floatTop->f -= f;
1562 		continue;
1563 
1564 		/*
1565 		 * Do float multiplication r1 * r2.
1566 		 * f* ( r1 r2 -- r )
1567 		 */
1568 		case ficlInstructionFStar:
1569 			CHECK_FLOAT_STACK(2, 1);
1570 
1571 			f = (floatTop--)->f;
1572 			floatTop->f *= f;
1573 		continue;
1574 
1575 		/*
1576 		 * Do float negation.
1577 		 * fnegate ( r -- r )
1578 		 */
1579 		case ficlInstructionFNegate:
1580 			CHECK_FLOAT_STACK(1, 1);
1581 
1582 			floatTop->f = -(floatTop->f);
1583 		continue;
1584 
1585 		/*
1586 		 * Do float division r1 / r2.
1587 		 * f/ ( r1 r2 -- r )
1588 		 */
1589 		case ficlInstructionFSlash:
1590 			CHECK_FLOAT_STACK(2, 1);
1591 
1592 			f = (floatTop--)->f;
1593 			floatTop->f /= f;
1594 		continue;
1595 
1596 		/*
1597 		 * Do float + integer r + n.
1598 		 * f+i ( r n -- r )
1599 		 */
1600 		case ficlInstructionFPlusI:
1601 			CHECK_FLOAT_STACK(1, 1);
1602 			CHECK_STACK(1, 0);
1603 
1604 			f = (ficlFloat)(dataTop--)->f;
1605 			floatTop->f += f;
1606 		continue;
1607 
1608 		/*
1609 		 * Do float - integer r - n.
1610 		 * f-i ( r n -- r )
1611 		 */
1612 		case ficlInstructionFMinusI:
1613 			CHECK_FLOAT_STACK(1, 1);
1614 			CHECK_STACK(1, 0);
1615 
1616 			f = (ficlFloat)(dataTop--)->f;
1617 			floatTop->f -= f;
1618 		continue;
1619 
1620 		/*
1621 		 * Do float * integer r * n.
1622 		 * f*i ( r n -- r )
1623 		 */
1624 		case ficlInstructionFStarI:
1625 			CHECK_FLOAT_STACK(1, 1);
1626 			CHECK_STACK(1, 0);
1627 
1628 			f = (ficlFloat)(dataTop--)->f;
1629 			floatTop->f *= f;
1630 		continue;
1631 
1632 		/*
1633 		 * Do float / integer r / n.
1634 		 * f/i ( r n -- r )
1635 		 */
1636 		case ficlInstructionFSlashI:
1637 			CHECK_FLOAT_STACK(1, 1);
1638 			CHECK_STACK(1, 0);
1639 
1640 			f = (ficlFloat)(dataTop--)->f;
1641 			floatTop->f /= f;
1642 			continue;
1643 
1644 		/*
1645 		 * Do integer - float n - r.
1646 		 * i-f ( n r -- r )
1647 		 */
1648 		case ficlInstructionIMinusF:
1649 			CHECK_FLOAT_STACK(1, 1);
1650 			CHECK_STACK(1, 0);
1651 
1652 			f = (ficlFloat)(dataTop--)->f;
1653 			floatTop->f = f - floatTop->f;
1654 		continue;
1655 
1656 		/*
1657 		 * Do integer / float n / r.
1658 		 * i/f ( n r -- r )
1659 		 */
1660 		case ficlInstructionISlashF:
1661 			CHECK_FLOAT_STACK(1, 1);
1662 			CHECK_STACK(1, 0);
1663 
1664 			f = (ficlFloat)(dataTop--)->f;
1665 			floatTop->f = f / floatTop->f;
1666 		continue;
1667 
1668 		/*
1669 		 * Do integer to float conversion.
1670 		 * int>float ( n -- r )
1671 		 */
1672 		case ficlInstructionIntToFloat:
1673 			CHECK_STACK(1, 0);
1674 			CHECK_FLOAT_STACK(0, 1);
1675 
1676 			(++floatTop)->f = ((dataTop--)->f);
1677 		continue;
1678 
1679 		/*
1680 		 * Do float to integer conversion.
1681 		 * float>int ( r -- n )
1682 		 */
1683 		case ficlInstructionFloatToInt:
1684 			CHECK_STACK(0, 1);
1685 			CHECK_FLOAT_STACK(1, 0);
1686 
1687 			(++dataTop)->i = ((floatTop--)->i);
1688 		continue;
1689 
1690 		/*
1691 		 * Add a floating point number to contents of a variable.
1692 		 * f+! ( r n -- )
1693 		 */
1694 		case ficlInstructionFPlusStore: {
1695 			ficlCell *cell;
1696 
1697 			CHECK_STACK(1, 0);
1698 			CHECK_FLOAT_STACK(1, 0);
1699 
1700 			cell = (ficlCell *)(dataTop--)->p;
1701 			cell->f += (floatTop--)->f;
1702 		continue;
1703 		}
1704 
1705 		/*
1706 		 * Do float stack drop.
1707 		 * fdrop ( r -- )
1708 		 */
1709 		case ficlInstructionFDrop:
1710 			CHECK_FLOAT_STACK(1, 0);
1711 			floatTop--;
1712 		continue;
1713 
1714 		/*
1715 		 * Do float stack ?dup.
1716 		 * f?dup ( r -- r )
1717 		 */
1718 		case ficlInstructionFQuestionDup:
1719 			CHECK_FLOAT_STACK(1, 2);
1720 
1721 			if (floatTop->f != 0)
1722 				goto FDUP;
1723 
1724 		continue;
1725 
1726 		/*
1727 		 * Do float stack dup.
1728 		 * fdup ( r -- r r )
1729 		 */
1730 		case ficlInstructionFDup:
1731 			CHECK_FLOAT_STACK(1, 2);
1732 
1733 FDUP:
1734 			floatTop[1] = floatTop[0];
1735 			floatTop++;
1736 			continue;
1737 
1738 		/*
1739 		 * Do float stack swap.
1740 		 * fswap ( r1 r2 -- r2 r1 )
1741 		 */
1742 		case ficlInstructionFSwap:
1743 			CHECK_FLOAT_STACK(2, 2);
1744 
1745 			c = floatTop[0];
1746 			floatTop[0] = floatTop[-1];
1747 			floatTop[-1] = c;
1748 		continue;
1749 
1750 		/*
1751 		 * Do float stack 2drop.
1752 		 * f2drop ( r r -- )
1753 		 */
1754 		case ficlInstructionF2Drop:
1755 			CHECK_FLOAT_STACK(2, 0);
1756 
1757 			floatTop -= 2;
1758 		continue;
1759 
1760 		/*
1761 		 * Do float stack 2dup.
1762 		 * f2dup ( r1 r2 -- r1 r2 r1 r2 )
1763 		 */
1764 		case ficlInstructionF2Dup:
1765 			CHECK_FLOAT_STACK(2, 4);
1766 
1767 			floatTop[1] = floatTop[-1];
1768 			floatTop[2] = *floatTop;
1769 			floatTop += 2;
1770 		continue;
1771 
1772 		/*
1773 		 * Do float stack over.
1774 		 * fover ( r1 r2 -- r1 r2 r1 )
1775 		 */
1776 		case ficlInstructionFOver:
1777 			CHECK_FLOAT_STACK(2, 3);
1778 
1779 			floatTop[1] = floatTop[-1];
1780 			floatTop++;
1781 		continue;
1782 
1783 		/*
1784 		 * Do float stack 2over.
1785 		 * f2over ( r1 r2 r3 -- r1 r2 r3 r1 r2 )
1786 		 */
1787 		case ficlInstructionF2Over:
1788 			CHECK_FLOAT_STACK(4, 6);
1789 
1790 			floatTop[1] = floatTop[-2];
1791 			floatTop[2] = floatTop[-1];
1792 			floatTop += 2;
1793 		continue;
1794 
1795 		/*
1796 		 * Do float stack pick.
1797 		 * fpick ( n -- r )
1798 		 */
1799 		case ficlInstructionFPick:
1800 			CHECK_STACK(1, 0);
1801 			c = *dataTop--;
1802 			CHECK_FLOAT_STACK(c.i+2, c.i+3);
1803 
1804 			floatTop[1] = floatTop[- c.i - 1];
1805 		continue;
1806 
1807 		/*
1808 		 * Do float stack rot.
1809 		 * frot ( r1 r2 r3  -- r2 r3 r1 )
1810 		 */
1811 		case ficlInstructionFRot:
1812 			i = 2;
1813 		goto FROLL;
1814 
1815 		/*
1816 		 * Do float stack roll.
1817 		 * froll ( n -- )
1818 		 */
1819 		case ficlInstructionFRoll:
1820 			CHECK_STACK(1, 0);
1821 			i = (dataTop--)->i;
1822 
1823 			if (i < 1)
1824 				continue;
1825 
1826 FROLL:
1827 			CHECK_FLOAT_STACK(i+1, i+2);
1828 			c = floatTop[-i];
1829 			memmove(floatTop - i, floatTop - (i - 1),
1830 			    i * sizeof (ficlCell));
1831 			*floatTop = c;
1832 
1833 		continue;
1834 
1835 		/*
1836 		 * Do float stack -rot.
1837 		 * f-rot ( r1 r2 r3  -- r3 r1 r2 )
1838 		 */
1839 		case ficlInstructionFMinusRot:
1840 			i = 2;
1841 			goto FMINUSROLL;
1842 
1843 
1844 		/*
1845 		 * Do float stack -roll.
1846 		 * f-roll ( n -- )
1847 		 */
1848 		case ficlInstructionFMinusRoll:
1849 			CHECK_STACK(1, 0);
1850 			i = (dataTop--)->i;
1851 
1852 			if (i < 1)
1853 				continue;
1854 
1855 FMINUSROLL:
1856 			CHECK_FLOAT_STACK(i+1, i+2);
1857 			c = *floatTop;
1858 			memmove(floatTop - (i - 1), floatTop - i,
1859 			    i * sizeof (ficlCell));
1860 			floatTop[-i] = c;
1861 
1862 		continue;
1863 
1864 		/*
1865 		 * Do float stack 2swap
1866 		 * f2swap ( r1 r2 r3 r4  -- r3 r4 r1 r2 )
1867 		 */
1868 		case ficlInstructionF2Swap: {
1869 			ficlCell c2;
1870 			CHECK_FLOAT_STACK(4, 4);
1871 
1872 			c = *floatTop;
1873 			c2 = floatTop[-1];
1874 
1875 			*floatTop = floatTop[-2];
1876 			floatTop[-1] = floatTop[-3];
1877 
1878 			floatTop[-2] = c;
1879 			floatTop[-3] = c2;
1880 		continue;
1881 		}
1882 
1883 		/*
1884 		 * Do float 0= comparison r = 0.0.
1885 		 * f0= ( r -- T/F )
1886 		 */
1887 		case ficlInstructionF0Equals:
1888 			CHECK_FLOAT_STACK(1, 0);
1889 			CHECK_STACK(0, 1);
1890 
1891 			(++dataTop)->i = FICL_BOOL((floatTop--)->f != 0.0f);
1892 		continue;
1893 
1894 		/*
1895 		 * Do float 0< comparison r < 0.0.
1896 		 * f0< ( r -- T/F )
1897 		 */
1898 		case ficlInstructionF0Less:
1899 			CHECK_FLOAT_STACK(1, 0);
1900 			CHECK_STACK(0, 1);
1901 
1902 			(++dataTop)->i = FICL_BOOL((floatTop--)->f < 0.0f);
1903 		continue;
1904 
1905 		/*
1906 		 * Do float 0> comparison r > 0.0.
1907 		 * f0> ( r -- T/F )
1908 		 */
1909 		case ficlInstructionF0Greater:
1910 			CHECK_FLOAT_STACK(1, 0);
1911 			CHECK_STACK(0, 1);
1912 
1913 			(++dataTop)->i = FICL_BOOL((floatTop--)->f > 0.0f);
1914 		continue;
1915 
1916 		/*
1917 		 * Do float = comparison r1 = r2.
1918 		 * f= ( r1 r2 -- T/F )
1919 		 */
1920 		case ficlInstructionFEquals:
1921 			CHECK_FLOAT_STACK(2, 0);
1922 			CHECK_STACK(0, 1);
1923 
1924 			f = (floatTop--)->f;
1925 			(++dataTop)->i = FICL_BOOL((floatTop--)->f == f);
1926 		continue;
1927 
1928 		/*
1929 		 * Do float < comparison r1 < r2.
1930 		 * f< ( r1 r2 -- T/F )
1931 		 */
1932 		case ficlInstructionFLess:
1933 			CHECK_FLOAT_STACK(2, 0);
1934 			CHECK_STACK(0, 1);
1935 
1936 			f = (floatTop--)->f;
1937 			(++dataTop)->i = FICL_BOOL((floatTop--)->f < f);
1938 		continue;
1939 
1940 		/*
1941 		 * Do float > comparison r1 > r2.
1942 		 * f> ( r1 r2 -- T/F )
1943 		 */
1944 		case ficlInstructionFGreater:
1945 			CHECK_FLOAT_STACK(2, 0);
1946 			CHECK_STACK(0, 1);
1947 
1948 			f = (floatTop--)->f;
1949 			(++dataTop)->i = FICL_BOOL((floatTop--)->f > f);
1950 		continue;
1951 
1952 
1953 		/*
1954 		 * Move float to param stack (assumes they both fit in a
1955 		 * single ficlCell) f>s
1956 		 */
1957 		case ficlInstructionFFrom:
1958 			CHECK_FLOAT_STACK(1, 0);
1959 			CHECK_STACK(0, 1);
1960 
1961 			*++dataTop = *floatTop--;
1962 		continue;
1963 
1964 		case ficlInstructionToF:
1965 			CHECK_FLOAT_STACK(0, 1);
1966 			CHECK_STACK(1, 0);
1967 
1968 			*++floatTop = *dataTop--;
1969 		continue;
1970 
1971 #endif /* FICL_WANT_FLOAT */
1972 
1973 		/*
1974 		 * c o l o n P a r e n
1975 		 * This is the code that executes a colon definition. It
1976 		 * assumes that the virtual machine is running a "next" loop
1977 		 * (See the vm.c for its implementation of member function
1978 		 * vmExecute()). The colon code simply copies the address of
1979 		 * the first word in the list of words to interpret into IP
1980 		 * after saving its old value. When we return to the "next"
1981 		 * loop, the virtual machine will call the code for each
1982 		 * word in turn.
1983 		 */
1984 		case ficlInstructionColonParen:
1985 			(++returnTop)->p = (void *)ip;
1986 			ip = (ficlInstruction *)(fw->param);
1987 		continue;
1988 
1989 		case ficlInstructionCreateParen:
1990 			CHECK_STACK(0, 1);
1991 			(++dataTop)->p = (fw->param + 1);
1992 		continue;
1993 
1994 		case ficlInstructionVariableParen:
1995 			CHECK_STACK(0, 1);
1996 			(++dataTop)->p = fw->param;
1997 		continue;
1998 
1999 		/*
2000 		 * c o n s t a n t P a r e n
2001 		 * This is the run-time code for "constant". It simply returns
2002 		 * the contents of its word's first data ficlCell.
2003 		 */
2004 
2005 #if FICL_WANT_FLOAT
2006 		case ficlInstructionF2ConstantParen:
2007 			CHECK_FLOAT_STACK(0, 2);
2008 			FLOAT_PUSH_CELL_POINTER_DOUBLE(fw->param);
2009 
2010 		case ficlInstructionFConstantParen:
2011 			CHECK_FLOAT_STACK(0, 1);
2012 			FLOAT_PUSH_CELL_POINTER(fw->param);
2013 #endif /* FICL_WANT_FLOAT */
2014 
2015 		case ficlInstruction2ConstantParen:
2016 			CHECK_STACK(0, 2);
2017 			PUSH_CELL_POINTER_DOUBLE(fw->param);
2018 
2019 		case ficlInstructionConstantParen:
2020 			CHECK_STACK(0, 1);
2021 			PUSH_CELL_POINTER(fw->param);
2022 
2023 #if FICL_WANT_USER
2024 		case ficlInstructionUserParen: {
2025 			ficlInteger i = fw->param[0].i;
2026 			(++dataTop)->p = &vm->user[i];
2027 		continue;
2028 		}
2029 #endif
2030 
2031 		default:
2032 		/*
2033 		 * Clever hack, or evil coding?  You be the judge.
2034 		 *
2035 		 * If the word we've been asked to execute is in fact
2036 		 * an *instruction*, we grab the instruction, stow it
2037 		 * in "i" (our local cache of *ip), and *jump* to the
2038 		 * top of the switch statement.  --lch
2039 		 */
2040 			if (((ficlInstruction)fw->code >
2041 			    ficlInstructionInvalid) &&
2042 			    ((ficlInstruction)fw->code < ficlInstructionLast)) {
2043 				instruction = (ficlInstruction)fw->code;
2044 				goto AGAIN;
2045 			}
2046 
2047 			LOCAL_VARIABLE_SPILL;
2048 			(vm)->runningWord = fw;
2049 			fw->code(vm);
2050 			LOCAL_VARIABLE_REFILL;
2051 		continue;
2052 		}
2053 	}
2054 
2055 	LOCAL_VARIABLE_SPILL;
2056 	vm->exceptionHandler = oldExceptionHandler;
2057 }
2058 
2059 /*
2060  * v m G e t D i c t
2061  * Returns the address dictionary for this VM's system
2062  */
2063 ficlDictionary *
2064 ficlVmGetDictionary(ficlVm *vm)
2065 {
2066 	FICL_VM_ASSERT(vm, vm);
2067 	return (vm->callback.system->dictionary);
2068 }
2069 
2070 /*
2071  * v m G e t S t r i n g
2072  * Parses a string out of the VM input buffer and copies up to the first
2073  * FICL_COUNTED_STRING_MAX characters to the supplied destination buffer, a
2074  * ficlCountedString. The destination string is NULL terminated.
2075  *
2076  * Returns the address of the first unused character in the dest buffer.
2077  */
2078 char *
2079 ficlVmGetString(ficlVm *vm, ficlCountedString *counted, char delimiter)
2080 {
2081 	ficlString s = ficlVmParseStringEx(vm, delimiter, 0);
2082 
2083 	if (FICL_STRING_GET_LENGTH(s) > FICL_COUNTED_STRING_MAX) {
2084 		FICL_STRING_SET_LENGTH(s, FICL_COUNTED_STRING_MAX);
2085 	}
2086 
2087 	strncpy(counted->text, FICL_STRING_GET_POINTER(s),
2088 	    FICL_STRING_GET_LENGTH(s));
2089 	counted->text[FICL_STRING_GET_LENGTH(s)] = '\0';
2090 	counted->length = (ficlUnsigned8)FICL_STRING_GET_LENGTH(s);
2091 
2092 	return (counted->text + FICL_STRING_GET_LENGTH(s) + 1);
2093 }
2094 
2095 /*
2096  * v m G e t W o r d
2097  * vmGetWord calls vmGetWord0 repeatedly until it gets a string with
2098  * non-zero length.
2099  */
2100 ficlString
2101 ficlVmGetWord(ficlVm *vm)
2102 {
2103 	ficlString s = ficlVmGetWord0(vm);
2104 
2105 	if (FICL_STRING_GET_LENGTH(s) == 0) {
2106 		ficlVmThrow(vm, FICL_VM_STATUS_RESTART);
2107 	}
2108 
2109 	return (s);
2110 }
2111 
2112 /*
2113  * v m G e t W o r d 0
2114  * Skip leading whitespace and parse a space delimited word from the tib.
2115  * Returns the start address and length of the word. Updates the tib
2116  * to reflect characters consumed, including the trailing delimiter.
2117  * If there's nothing of interest in the tib, returns zero. This function
2118  * does not use vmParseString because it uses isspace() rather than a
2119  * single  delimiter character.
2120  */
2121 ficlString
2122 ficlVmGetWord0(ficlVm *vm)
2123 {
2124 	char *trace = ficlVmGetInBuf(vm);
2125 	char *stop = ficlVmGetInBufEnd(vm);
2126 	ficlString s;
2127 	ficlUnsigned length = 0;
2128 	char c = 0;
2129 
2130 	trace = ficlStringSkipSpace(trace, stop);
2131 	FICL_STRING_SET_POINTER(s, trace);
2132 
2133 	/* Please leave this loop this way; it makes Purify happier.  --lch */
2134 	for (;;) {
2135 		if (trace == stop)
2136 			break;
2137 		c = *trace;
2138 		if (isspace((unsigned char)c))
2139 			break;
2140 		length++;
2141 		trace++;
2142 	}
2143 
2144 	FICL_STRING_SET_LENGTH(s, length);
2145 
2146 	/* skip one trailing delimiter */
2147 	if ((trace != stop) && isspace((unsigned char)c))
2148 		trace++;
2149 
2150 	ficlVmUpdateTib(vm, trace);
2151 
2152 	return (s);
2153 }
2154 
2155 /*
2156  * v m G e t W o r d T o P a d
2157  * Does vmGetWord and copies the result to the pad as a NULL terminated
2158  * string. Returns the length of the string. If the string is too long
2159  * to fit in the pad, it is truncated.
2160  */
2161 int
2162 ficlVmGetWordToPad(ficlVm *vm)
2163 {
2164 	ficlString s;
2165 	char *pad = (char *)vm->pad;
2166 	s = ficlVmGetWord(vm);
2167 
2168 	if (FICL_STRING_GET_LENGTH(s) > FICL_PAD_SIZE)
2169 		FICL_STRING_SET_LENGTH(s, FICL_PAD_SIZE);
2170 
2171 	strncpy(pad, FICL_STRING_GET_POINTER(s), FICL_STRING_GET_LENGTH(s));
2172 	pad[FICL_STRING_GET_LENGTH(s)] = '\0';
2173 	return ((int)(FICL_STRING_GET_LENGTH(s)));
2174 }
2175 
2176 /*
2177  * v m P a r s e S t r i n g
2178  * Parses a string out of the input buffer using the delimiter
2179  * specified. Skips leading delimiters, marks the start of the string,
2180  * and counts characters to the next delimiter it encounters. It then
2181  * updates the vm input buffer to consume all these chars, including the
2182  * trailing delimiter.
2183  * Returns the address and length of the parsed string, not including the
2184  * trailing delimiter.
2185  */
2186 ficlString
2187 ficlVmParseString(ficlVm *vm, char delimiter)
2188 {
2189 	return (ficlVmParseStringEx(vm, delimiter, 1));
2190 }
2191 
2192 ficlString
2193 ficlVmParseStringEx(ficlVm *vm, char delimiter, char skipLeadingDelimiters)
2194 {
2195 	ficlString s;
2196 	char *trace = ficlVmGetInBuf(vm);
2197 	char *stop = ficlVmGetInBufEnd(vm);
2198 	char c;
2199 
2200 	if (skipLeadingDelimiters) {
2201 		while ((trace != stop) && (*trace == delimiter))
2202 			trace++;
2203 	}
2204 
2205 	FICL_STRING_SET_POINTER(s, trace);    /* mark start of text */
2206 
2207 	/* find next delimiter or end of line */
2208 	for (c = *trace;
2209 	    (trace != stop) && (c != delimiter) && (c != '\r') && (c != '\n');
2210 	    c = *++trace) {
2211 		;
2212 	}
2213 
2214 	/* set length of result */
2215 	FICL_STRING_SET_LENGTH(s, trace - FICL_STRING_GET_POINTER(s));
2216 
2217 	/* gobble trailing delimiter */
2218 	if ((trace != stop) && (*trace == delimiter))
2219 		trace++;
2220 
2221 	ficlVmUpdateTib(vm, trace);
2222 	return (s);
2223 }
2224 
2225 
2226 /*
2227  * v m P o p
2228  */
2229 ficlCell
2230 ficlVmPop(ficlVm *vm)
2231 {
2232 	return (ficlStackPop(vm->dataStack));
2233 }
2234 
2235 /*
2236  * v m P u s h
2237  */
2238 void
2239 ficlVmPush(ficlVm *vm, ficlCell c)
2240 {
2241 	ficlStackPush(vm->dataStack, c);
2242 }
2243 
2244 /*
2245  * v m P o p I P
2246  */
2247 void
2248 ficlVmPopIP(ficlVm *vm)
2249 {
2250 	vm->ip = (ficlIp)(ficlStackPopPointer(vm->returnStack));
2251 }
2252 
2253 /*
2254  * v m P u s h I P
2255  */
2256 void
2257 ficlVmPushIP(ficlVm *vm, ficlIp newIP)
2258 {
2259 	ficlStackPushPointer(vm->returnStack, (void *)vm->ip);
2260 	vm->ip = newIP;
2261 }
2262 
2263 /*
2264  * v m P u s h T i b
2265  * Binds the specified input string to the VM and clears >IN (the index)
2266  */
2267 void
2268 ficlVmPushTib(ficlVm *vm, char *text, ficlInteger nChars, ficlTIB *pSaveTib)
2269 {
2270 	if (pSaveTib) {
2271 		*pSaveTib = vm->tib;
2272 	}
2273 	vm->tib.text = text;
2274 	vm->tib.end = text + nChars;
2275 	vm->tib.index = 0;
2276 }
2277 
2278 void
2279 ficlVmPopTib(ficlVm *vm, ficlTIB *pTib)
2280 {
2281 	if (pTib) {
2282 		vm->tib = *pTib;
2283 	}
2284 }
2285 
2286 /*
2287  * v m Q u i t
2288  */
2289 void
2290 ficlVmQuit(ficlVm *vm)
2291 {
2292 	ficlStackReset(vm->returnStack);
2293 	vm->restart = 0;
2294 	vm->ip = NULL;
2295 	vm->runningWord = NULL;
2296 	vm->state = FICL_VM_STATE_INTERPRET;
2297 	vm->tib.text = NULL;
2298 	vm->tib.end = NULL;
2299 	vm->tib.index = 0;
2300 	vm->pad[0] = '\0';
2301 	vm->sourceId.i = 0;
2302 }
2303 
2304 /*
2305  * v m R e s e t
2306  */
2307 void
2308 ficlVmReset(ficlVm *vm)
2309 {
2310 	ficlVmQuit(vm);
2311 	ficlStackReset(vm->dataStack);
2312 #if FICL_WANT_FLOAT
2313 	ficlStackReset(vm->floatStack);
2314 #endif
2315 	vm->base = 10;
2316 }
2317 
2318 /*
2319  * v m S e t T e x t O u t
2320  * Binds the specified output callback to the vm. If you pass NULL,
2321  * binds the default output function (ficlTextOut)
2322  */
2323 void
2324 ficlVmSetTextOut(ficlVm *vm, ficlOutputFunction textOut)
2325 {
2326 	vm->callback.textOut = textOut;
2327 }
2328 
2329 void
2330 ficlVmTextOut(ficlVm *vm, char *text)
2331 {
2332 	ficlCallbackTextOut((ficlCallback *)vm, text);
2333 }
2334 
2335 
2336 void
2337 ficlVmErrorOut(ficlVm *vm, char *text)
2338 {
2339 	ficlCallbackErrorOut((ficlCallback *)vm, text);
2340 }
2341 
2342 
2343 /*
2344  * v m T h r o w
2345  */
2346 void
2347 ficlVmThrow(ficlVm *vm, int except)
2348 {
2349 	if (vm->exceptionHandler)
2350 		longjmp(*(vm->exceptionHandler), except);
2351 }
2352 
2353 void
2354 ficlVmThrowError(ficlVm *vm, char *fmt, ...)
2355 {
2356 	va_list list;
2357 
2358 	va_start(list, fmt);
2359 	vsprintf(vm->pad, fmt, list);
2360 	va_end(list);
2361 	strcat(vm->pad, "\n");
2362 
2363 	ficlVmErrorOut(vm, vm->pad);
2364 	longjmp(*(vm->exceptionHandler), FICL_VM_STATUS_ERROR_EXIT);
2365 }
2366 
2367 void
2368 ficlVmThrowErrorVararg(ficlVm *vm, char *fmt, va_list list)
2369 {
2370 	vsprintf(vm->pad, fmt, list);
2371 	/*
2372 	 * well, we can try anyway, we're certainly not
2373 	 * returning to our caller!
2374 	 */
2375 	va_end(list);
2376 	strcat(vm->pad, "\n");
2377 
2378 	ficlVmErrorOut(vm, vm->pad);
2379 	longjmp(*(vm->exceptionHandler), FICL_VM_STATUS_ERROR_EXIT);
2380 }
2381 
2382 /*
2383  * f i c l E v a l u a t e
2384  * Wrapper for ficlExec() which sets SOURCE-ID to -1.
2385  */
2386 int
2387 ficlVmEvaluate(ficlVm *vm, char *s)
2388 {
2389 	int returnValue;
2390 	ficlCell id = vm->sourceId;
2391 	ficlString string;
2392 	vm->sourceId.i = -1;
2393 	FICL_STRING_SET_FROM_CSTRING(string, s);
2394 	returnValue = ficlVmExecuteString(vm, string);
2395 	vm->sourceId = id;
2396 	return (returnValue);
2397 }
2398 
2399 /*
2400  * f i c l E x e c
2401  * Evaluates a block of input text in the context of the
2402  * specified interpreter. Emits any requested output to the
2403  * interpreter's output function.
2404  *
2405  * Contains the "inner interpreter" code in a tight loop
2406  *
2407  * Returns one of the VM_XXXX codes defined in ficl.h:
2408  * VM_OUTOFTEXT is the normal exit condition
2409  * VM_ERREXIT means that the interpreter encountered a syntax error
2410  *      and the vm has been reset to recover (some or all
2411  *      of the text block got ignored
2412  * VM_USEREXIT means that the user executed the "bye" command
2413  *      to shut down the interpreter. This would be a good
2414  *      time to delete the vm, etc -- or you can ignore this
2415  *      signal.
2416  */
2417 int
2418 ficlVmExecuteString(ficlVm *vm, ficlString s)
2419 {
2420 	ficlSystem *system = vm->callback.system;
2421 	ficlDictionary *dictionary = system->dictionary;
2422 
2423 	int except;
2424 	jmp_buf vmState;
2425 	jmp_buf *oldState;
2426 	ficlTIB saveficlTIB;
2427 
2428 	FICL_VM_ASSERT(vm, vm);
2429 	FICL_VM_ASSERT(vm, system->interpreterLoop[0]);
2430 
2431 	ficlVmPushTib(vm, FICL_STRING_GET_POINTER(s),
2432 	    FICL_STRING_GET_LENGTH(s), &saveficlTIB);
2433 
2434 	/*
2435 	 * Save and restore VM's jmp_buf to enable nested calls to ficlExec
2436 	 */
2437 	oldState = vm->exceptionHandler;
2438 
2439 	/* This has to come before the setjmp! */
2440 	vm->exceptionHandler = &vmState;
2441 	except = setjmp(vmState);
2442 
2443 	switch (except) {
2444 	case 0:
2445 		if (vm->restart) {
2446 			vm->runningWord->code(vm);
2447 			vm->restart = 0;
2448 		} else {	/* set VM up to interpret text */
2449 			ficlVmPushIP(vm, &(system->interpreterLoop[0]));
2450 		}
2451 
2452 		ficlVmInnerLoop(vm, 0);
2453 	break;
2454 
2455 	case FICL_VM_STATUS_RESTART:
2456 		vm->restart = 1;
2457 		except = FICL_VM_STATUS_OUT_OF_TEXT;
2458 	break;
2459 
2460 	case FICL_VM_STATUS_OUT_OF_TEXT:
2461 		ficlVmPopIP(vm);
2462 #if 0	/* we dont output prompt in loader */
2463 		if ((vm->state != FICL_VM_STATE_COMPILE) &&
2464 		    (vm->sourceId.i == 0))
2465 			ficlVmTextOut(vm, FICL_PROMPT);
2466 #endif
2467 	break;
2468 
2469 	case FICL_VM_STATUS_USER_EXIT:
2470 	case FICL_VM_STATUS_INNER_EXIT:
2471 	case FICL_VM_STATUS_BREAK:
2472 	break;
2473 
2474 	case FICL_VM_STATUS_QUIT:
2475 		if (vm->state == FICL_VM_STATE_COMPILE) {
2476 			ficlDictionaryAbortDefinition(dictionary);
2477 #if FICL_WANT_LOCALS
2478 			ficlDictionaryEmpty(system->locals,
2479 			    system->locals->forthWordlist->size);
2480 #endif
2481 		}
2482 		ficlVmQuit(vm);
2483 	break;
2484 
2485 	case FICL_VM_STATUS_ERROR_EXIT:
2486 	case FICL_VM_STATUS_ABORT:
2487 	case FICL_VM_STATUS_ABORTQ:
2488 	default:		/* user defined exit code?? */
2489 		if (vm->state == FICL_VM_STATE_COMPILE) {
2490 			ficlDictionaryAbortDefinition(dictionary);
2491 #if FICL_WANT_LOCALS
2492 			ficlDictionaryEmpty(system->locals,
2493 			    system->locals->forthWordlist->size);
2494 #endif
2495 		}
2496 		ficlDictionaryResetSearchOrder(dictionary);
2497 		ficlVmReset(vm);
2498 	break;
2499 	}
2500 
2501 	vm->exceptionHandler = oldState;
2502 	ficlVmPopTib(vm, &saveficlTIB);
2503 	return (except);
2504 }
2505 
2506 /*
2507  * f i c l E x e c X T
2508  * Given a pointer to a ficlWord, push an inner interpreter and
2509  * execute the word to completion. This is in contrast with vmExecute,
2510  * which does not guarantee that the word will have completed when
2511  * the function returns (ie in the case of colon definitions, which
2512  * need an inner interpreter to finish)
2513  *
2514  * Returns one of the VM_XXXX exception codes listed in ficl.h. Normal
2515  * exit condition is VM_INNEREXIT, Ficl's private signal to exit the
2516  * inner loop under normal circumstances. If another code is thrown to
2517  * exit the loop, this function will re-throw it if it's nested under
2518  * itself or ficlExec.
2519  *
2520  * NOTE: this function is intended so that C code can execute ficlWords
2521  * given their address in the dictionary (xt).
2522  */
2523 int
2524 ficlVmExecuteXT(ficlVm *vm, ficlWord *pWord)
2525 {
2526 	int except;
2527 	jmp_buf vmState;
2528 	jmp_buf *oldState;
2529 	ficlWord *oldRunningWord;
2530 
2531 	FICL_VM_ASSERT(vm, vm);
2532 	FICL_VM_ASSERT(vm, vm->callback.system->exitInnerWord);
2533 
2534 	/*
2535 	 * Save the runningword so that RESTART behaves correctly
2536 	 * over nested calls.
2537 	 */
2538 	oldRunningWord = vm->runningWord;
2539 	/*
2540 	 * Save and restore VM's jmp_buf to enable nested calls
2541 	 */
2542 	oldState = vm->exceptionHandler;
2543 	/* This has to come before the setjmp! */
2544 	vm->exceptionHandler = &vmState;
2545 	except = setjmp(vmState);
2546 
2547 	if (except)
2548 		ficlVmPopIP(vm);
2549 	else
2550 		ficlVmPushIP(vm, &(vm->callback.system->exitInnerWord));
2551 
2552 	switch (except) {
2553 	case 0:
2554 		ficlVmExecuteWord(vm, pWord);
2555 		ficlVmInnerLoop(vm, 0);
2556 	break;
2557 
2558 	case FICL_VM_STATUS_INNER_EXIT:
2559 	case FICL_VM_STATUS_BREAK:
2560 	break;
2561 
2562 	case FICL_VM_STATUS_RESTART:
2563 	case FICL_VM_STATUS_OUT_OF_TEXT:
2564 	case FICL_VM_STATUS_USER_EXIT:
2565 	case FICL_VM_STATUS_QUIT:
2566 	case FICL_VM_STATUS_ERROR_EXIT:
2567 	case FICL_VM_STATUS_ABORT:
2568 	case FICL_VM_STATUS_ABORTQ:
2569 	default:		/* user defined exit code?? */
2570 		if (oldState) {
2571 			vm->exceptionHandler = oldState;
2572 			ficlVmThrow(vm, except);
2573 		}
2574 	break;
2575 	}
2576 
2577 	vm->exceptionHandler = oldState;
2578 	vm->runningWord = oldRunningWord;
2579 	return (except);
2580 }
2581 
2582 /*
2583  * f i c l P a r s e N u m b e r
2584  * Attempts to convert the NULL terminated string in the VM's pad to
2585  * a number using the VM's current base. If successful, pushes the number
2586  * onto the param stack and returns FICL_TRUE. Otherwise, returns FICL_FALSE.
2587  * (jws 8/01) Trailing decimal point causes a zero ficlCell to be pushed. (See
2588  * the standard for DOUBLE wordset.
2589  */
2590 int
2591 ficlVmParseNumber(ficlVm *vm, ficlString s)
2592 {
2593 	ficlInteger accumulator = 0;
2594 	char isNegative = 0;
2595 	char isDouble = 0;
2596 	unsigned base = vm->base;
2597 	char *trace = FICL_STRING_GET_POINTER(s);
2598 	ficlUnsigned8 length = (ficlUnsigned8)FICL_STRING_GET_LENGTH(s);
2599 	unsigned c;
2600 	unsigned digit;
2601 
2602 	if (length > 1) {
2603 		switch (*trace) {
2604 		case '-':
2605 			trace++;
2606 			length--;
2607 			isNegative = 1;
2608 		break;
2609 		case '+':
2610 			trace++;
2611 			length--;
2612 			isNegative = 0;
2613 		break;
2614 		default:
2615 		break;
2616 		}
2617 	}
2618 
2619 	/* detect & remove trailing decimal */
2620 	if ((length > 0) && (trace[length - 1] == '.')) {
2621 		isDouble = 1;
2622 		length--;
2623 	}
2624 
2625 	if (length == 0)		/* detect "+", "-", ".", "+." etc */
2626 		return (0);		/* false */
2627 
2628 	while ((length--) && ((c = *trace++) != '\0')) {
2629 		if (!isalnum(c))
2630 			return (0);	/* false */
2631 
2632 		digit = c - '0';
2633 
2634 		if (digit > 9)
2635 			digit = tolower(c) - 'a' + 10;
2636 
2637 		if (digit >= base)
2638 			return (0);	/* false */
2639 
2640 		accumulator = accumulator * base + digit;
2641 	}
2642 
2643 	if (isNegative)
2644 		accumulator = -accumulator;
2645 
2646 	ficlStackPushInteger(vm->dataStack, accumulator);
2647 	if (vm->state == FICL_VM_STATE_COMPILE)
2648 		ficlPrimitiveLiteralIm(vm);
2649 
2650 	if (isDouble) {			/* simple (required) DOUBLE support */
2651 		if (isNegative)
2652 			ficlStackPushInteger(vm->dataStack, -1);
2653 		else
2654 			ficlStackPushInteger(vm->dataStack, 0);
2655 		if (vm->state == FICL_VM_STATE_COMPILE)
2656 			ficlPrimitiveLiteralIm(vm);
2657 	}
2658 
2659 	return (1); /* true */
2660 }
2661 
2662 /*
2663  * d i c t C h e c k
2664  * Checks the dictionary for corruption and throws appropriate
2665  * errors.
2666  * Input: +n number of ADDRESS UNITS (not ficlCells) proposed to allot
2667  *        -n number of ADDRESS UNITS proposed to de-allot
2668  *         0 just do a consistency check
2669  */
2670 void
2671 ficlVmDictionarySimpleCheck(ficlVm *vm, ficlDictionary *dictionary, int cells)
2672 {
2673 #if FICL_ROBUST >= 1
2674 	if ((cells >= 0) &&
2675 	    (ficlDictionaryCellsAvailable(dictionary) *
2676 	    (int)sizeof (ficlCell) < cells)) {
2677 		ficlVmThrowError(vm, "Error: dictionary full");
2678 	}
2679 
2680 	if ((cells <= 0) &&
2681 	    (ficlDictionaryCellsUsed(dictionary) *
2682 	    (int)sizeof (ficlCell) < -cells)) {
2683 		ficlVmThrowError(vm, "Error: dictionary underflow");
2684 	}
2685 #else /* FICL_ROBUST >= 1 */
2686 	FICL_IGNORE(vm);
2687 	FICL_IGNORE(dictionary);
2688 	FICL_IGNORE(cells);
2689 #endif /* FICL_ROBUST >= 1 */
2690 }
2691 
2692 void
2693 ficlVmDictionaryCheck(ficlVm *vm, ficlDictionary *dictionary, int cells)
2694 {
2695 #if FICL_ROBUST >= 1
2696 	ficlVmDictionarySimpleCheck(vm, dictionary, cells);
2697 
2698 	if (dictionary->wordlistCount > FICL_MAX_WORDLISTS) {
2699 		ficlDictionaryResetSearchOrder(dictionary);
2700 		ficlVmThrowError(vm, "Error: search order overflow");
2701 	} else if (dictionary->wordlistCount < 0) {
2702 		ficlDictionaryResetSearchOrder(dictionary);
2703 		ficlVmThrowError(vm, "Error: search order underflow");
2704 	}
2705 #else /* FICL_ROBUST >= 1 */
2706 	FICL_IGNORE(vm);
2707 	FICL_IGNORE(dictionary);
2708 	FICL_IGNORE(cells);
2709 #endif /* FICL_ROBUST >= 1 */
2710 }
2711 
2712 void
2713 ficlVmDictionaryAllot(ficlVm *vm, ficlDictionary *dictionary, int n)
2714 {
2715 	FICL_VM_DICTIONARY_SIMPLE_CHECK(vm, dictionary, n);
2716 	FICL_IGNORE(vm);
2717 	ficlDictionaryAllot(dictionary, n);
2718 }
2719 
2720 void
2721 ficlVmDictionaryAllotCells(ficlVm *vm, ficlDictionary *dictionary, int cells)
2722 {
2723 	FICL_VM_DICTIONARY_SIMPLE_CHECK(vm, dictionary, cells);
2724 	FICL_IGNORE(vm);
2725 	ficlDictionaryAllotCells(dictionary, cells);
2726 }
2727 
2728 /*
2729  * f i c l P a r s e W o r d
2730  * From the standard, section 3.4
2731  * b) Search the dictionary name space (see 3.4.2). If a definition name
2732  * matching the string is found:
2733  *  1.if interpreting, perform the interpretation semantics of the definition
2734  *  (see 3.4.3.2), and continue at a);
2735  *  2.if compiling, perform the compilation semantics of the definition
2736  *  (see 3.4.3.3), and continue at a).
2737  *
2738  * c) If a definition name matching the string is not found, attempt to
2739  * convert the string to a number (see 3.4.1.3). If successful:
2740  *  1.if interpreting, place the number on the data stack, and continue at a);
2741  *  2.if compiling, FICL_VM_STATE_COMPILE code that when executed will place
2742  *  the number on the stack (see 6.1.1780 LITERAL), and continue at a);
2743  *
2744  * d) If unsuccessful, an ambiguous condition exists (see 3.4.4).
2745  *
2746  * (jws 4/01) Modified to be a ficlParseStep
2747  */
2748 int
2749 ficlVmParseWord(ficlVm *vm, ficlString name)
2750 {
2751 	ficlDictionary *dictionary = ficlVmGetDictionary(vm);
2752 	ficlWord *tempFW;
2753 
2754 	FICL_VM_DICTIONARY_CHECK(vm, dictionary, 0);
2755 	FICL_STACK_CHECK(vm->dataStack, 0, 0);
2756 
2757 #if FICL_WANT_LOCALS
2758 	if (vm->callback.system->localsCount > 0) {
2759 		tempFW = ficlSystemLookupLocal(vm->callback.system, name);
2760 	} else
2761 #endif
2762 		tempFW = ficlDictionaryLookup(dictionary, name);
2763 
2764 	if (vm->state == FICL_VM_STATE_INTERPRET) {
2765 		if (tempFW != NULL) {
2766 			if (ficlWordIsCompileOnly(tempFW)) {
2767 				ficlVmThrowError(vm,
2768 				    "Error: FICL_VM_STATE_COMPILE only!");
2769 			}
2770 
2771 			ficlVmExecuteWord(vm, tempFW);
2772 			return (1); /* true */
2773 		}
2774 	} else {	/* (vm->state == FICL_VM_STATE_COMPILE) */
2775 		if (tempFW != NULL) {
2776 			if (ficlWordIsImmediate(tempFW)) {
2777 				ficlVmExecuteWord(vm, tempFW);
2778 			} else {
2779 				ficlCell c;
2780 				c.p = tempFW;
2781 				if (tempFW->flags & FICL_WORD_INSTRUCTION)
2782 					ficlDictionaryAppendUnsigned(dictionary,
2783 					    (ficlInteger)tempFW->code);
2784 				else
2785 					ficlDictionaryAppendCell(dictionary, c);
2786 			}
2787 			return (1); /* true */
2788 		}
2789 	}
2790 
2791 	return (0); /* false */
2792 }
2793