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1.1 root 1: TTL MINIMAL -- MACHINE INDEPENDENT MACRO ASSEMBLY LANG.
2: EJC
3: *
4: * THE FOLLOWING SECTIONS DESCRIBE THE IMPLEMENTATION
5: * LANGUAGE ORIGINALLY DEVELOPED FOR SPITBOL BUT NOW MORE
6: * WIDELY USED. MINIMAL IS AN ASSEMBLY LANGUAGE
7: * FOR AN IDEALIZED MACHINE. THE FOLLOWING DESCRIBES THE
8: * BASIC CHARACTERISTICS OF THIS MACHINE.
9: *
10: * SECTION 1 - CONFIGURATION PARAMETERS
11: *
12: * THERE ARE SEVERAL PARAMETERS WHICH MAY VARY WITH THE
13: * TARGET MACHINE. THE MACRO-PROGRAM IS INDEPENDENT OF THE
14: * ACTUAL DEFINITIONS OF THESE PARAMETERS.
15: *
16: * THE DEFINITIONS OF THESE PARAMETERS ARE SUPPLIED BY
17: * THE TRANSLATION PROGRAM TO MATCH THE TARGET MACHINE.
18: *
19: * CFP$A NUMBER OF DISTINCT CHARACTERS IN
20: * INTERNAL ALPHABET IN THE RANGE
21: * 64 LE CFP$A LE MXLEN.
22: *
23: * CFP$B NUMBER OF BYTES IN A WORD WHERE A
24: * BYTE IS THE AMOUNT OF STORAGE
25: * ADDRESSED BY THE LEAST SIGNIFICANT
26: * ADDRESS BIT.
27: *
28: * CFP$C NUMBER OF CHARACTERS WHICH CAN
29: * BE STORED IN A SINGLE WORD.
30: *
31: * CFP$F BYTE OFFSET FROM START OF A STRING
32: * BLOCK TO THE FIRST CHARACTER.
33: * DEPENDS BOTH ON TARGET MACHINE AND
34: * STRING DATA STRUCTURE. SEE PLC, PSC
35: *
36: * CFP$I NUMBER OF WORDS IN A SIGNED
37: * INTEGER CONSTANT
38: *
39: * CFP$M THE LARGEST POSITIVE INTEGER
40: * OF FORM 2**N - 1 WHICH CAN BE
41: * STORED IN A SINGLE WORD. N
42: * WILL OFTEN BE CFP$N BUT NEED NOT BE
43: *
44: *
45: * CFP$N NUMBER OF BITS WHICH CAN BE STORED
46: * IN A ONE WORD BIT STRING.
47: *
48: * CFP$R NUMBER OF WORDS IN A REAL CONSTANT
49: *
50: * CFP$S NUMBER OF SIGNIFICANT DIGITS TO
51: * BE OUTPUT IN CONVERSION OF A REAL
52: * QUANTITY. THE INTEGER CONSISTING OF
53: * THIS NUMBER OF 9S MUST NOT BE TOO
54: * LARGE TO FIT IN THE INTEGER ACCUM.
55: *
56: * CFP$X NUMBER OF DIGITS IN REAL EXPONENT
57: EJC
58: *
59: * SECTION 2 - MEMORY
60: *
61: * MEMORY IS ORGANIZED INTO WORDS WHICH EACH CONTAIN CFP$B
62: * BYTES. FOR WORD MACHINES CFP$B, WHICH IS A CONFIGURATION
63: * PARAMETER, MAY BE ONE IN WHICH CASE WORDS AND BYTES ARE
64: * IDENTICAL. TO EACH WORD CORRESPONDS AN ADDRESS WHICH IS
65: * A NON-NEGATIVE QUANTITY WHICH IS A MULTIPLE OF CFP$B.
66: * DATA IS ORGANIZED INTO WORDS AS FOLLOWS.
67: *
68: * 1) A SIGNED INTEGER VALUE OCCUPIES CFP$I CONSECUTIVE
69: * WORDS (CFP$I IS A CONFIGURATION PARAMETER).
70: * THE RANGE MAY INCLUDE MORE NEGATIVE NUMBERS THAN
71: * POSITIVE (E.G. THE TWOS COMPLEMENT REPRESENTATION).
72: *
73: * 2) A SIGNED REAL VALUE OCCUPIES CFP$R CONSECUTIVE
74: * WORDS. (CFP$R IS A CONFIGURATION PARAMETER).
75: *
76: * 3) CFP$C CHARACTERS MAY BE STORED IN A SINGLE WORD
77: * (CFP$C IS A CONFIGURATION PARAMETER).
78: *
79: * 4) A BIT STRING CONTAINING CFP$N BITS CAN BE STORED IN
80: * A SINGLE WORD (CFP$N IS A CONFIGURATION PARAMETER).
81: *
82: * 5) A WORD CAN CONTAIN A NON-NEGATIVE INTEGER VALUE IN
83: * THE RANGE (0 LE N LE CFP$M). THESE INTEGER VALUES
84: * MAY REPRESENT ADDRESSES OF OTHER WORDS AND SOME OF
85: * THE INSTRUCTIONS USE THIS FACT TO PROVIDE INDEXING
86: * AND INDIRECTION FACILITIES.
87: *
88: * 6) PROGRAM INSTRUCTIONS OCCUPY WORDS IN AN UNDEFINED
89: * MANNER. DEPENDING ON THE ACTUAL IMPLEMENTATION,
90: * INSTRUCTIONS MAY OCCUPY SEVERAL WORDS, OR PART OF
91: * A WORD, OR EVEN BE SPLIT OVER WORD BOUNDARIES.
92: *
93: * THE FOLLOWING REGIONS OF MEMORY ARE AVAILABLE TO THE
94: * PROGRAM. EACH REGION CONSISTS OF A SERIES OF WORDS WITH
95: * CONSECUTIVE ADDRESSES.
96: *
97: * 1) CONSTANT SECTION ASSEMBLED CONSTANTS
98: * 2) WORKING STORAGE SECTION ASSEMBLED WORK AREAS
99: * 3) PROGRAM SECTION ASSEMBLED INSTRUCTIONS
100: * 4) STACK AREA ALLOCATED STACK AREA
101: * 5) DATA AREA ALLOCATED DATA AREA
102: EJC
103: *
104: * SECTION 3 - REGISTERS
105: *
106: * THERE ARE THREE INDEX REGISTERS CALLED XR,XL,XS. IN
107: * ADDITION XL MAY SOMETIMES BE REFERRED TO BY THE ALIAS
108: * OF XT - SEE SECTION 4. ANY OF THE ABOVE
109: * REGISTERS MAY HOLD A POSITIVE INTEGER IN THE RANGE
110: * (0 LE N LE CFP$M). WHEN THE INDEX REGISTER IS USED FOR
111: * INDEXING PURPOSES, THIS MUST BE AN APPROPRIATE ADDRESS.
112: * XS IS SPECIAL IN THAT IT IS USED TO POINT TO THE TOP
113: * ITEM OF A STACK IN MEMORY. THE STACK MAY BUILD UP OR
114: * DOWN IN MEMORY.SINCE IT IS REQUIRED THAT XS POINTS TO THE
115: * STACK TOP BUT ACCESS TO ITEMS BELOW THE TOP IS PERMITTED,
116: * REGISTERS XS AND XT MAY BE USED WITH SUITABLE OFFSETS
117: * TO INDEX STACKED ITEMS. ONLY XS AND XT MAY BE USED FOR
118: * THIS PURPOSE SINCE THE DIRECTION OF THE OFFSET IS
119: * TARGET MACHINE DEPENDENT. XT IS A SYNONYM FOR XL
120: * WHICH THEREFORE CANNOT BE USED IN CODE SEQUENCES
121: * REFERENCING XT.
122: * THE STACK IS USED FOR S-R LINKAGE AND TEMPORARY
123: * DATA STORAGE FOR WHICH THE STACK ARRANGEMENT IS SUITABLE.
124: * XR,XL CAN ALSO CONTAIN A CHARACTER POINTER IN CONJUNCTION
125: * WITH THE CHARACTER INSTRUCTIONS (SEE DESCRIPTION OF PLC).
126: EJC
127: *
128: * THERE ARE THREE WORK REGISTERS CALLED WA,WB,WC WHICH
129: * CAN CONTAIN ANY DATA ITEM WHICH CAN BE STORED IN A
130: * SINGLE MEMORY WORD. IN FACT, THE WORK REGISTERS ARE JUST
131: * LIKE MEMORY LOCATIONS EXCEPT THAT THEY HAVE NO ADDRESSES
132: * AND ARE REFERENCED IN A SPECIAL WAY BY THE INSTRUCTIONS.
133: * NOTE THAT REGISTERS WA,WB HAVE SPECIAL USES IN CONNECTION
134: * WITH THE CVD, CVM, MVC, MVW, MWB, CMC, TRC INSTRUCTIONS.
135: * REGISTER WC MAY OVERLAP THE INTEGER ACCUMULATOR (IA) IN
136: * SOME IMPLEMENTATIONS. THUS ANY OPERATION CHANGING THE
137: * VALUE IN WC LEAVES (IA) UNDEFINED AND VICE VERSA
138: * EXCEPT AS NOTED IN THE FOLLOWING RESTRICTION ON SIMPLE
139: * DUMP/RESTORE OPERATIONS.
140: *
141: * RESTRICTION
142: * -----------
143: *
144: * IF IA AND WA OVERLAP THEN
145: * STI IASAV
146: * LDI IASAV
147: * DOES NOT CHANGE WC, AND
148: * MOV WC,WCSAV
149: * MOV WCSAV,WC
150: * DOES NOT CHANGE IA.
151: *
152: *
153: *
154: * THERE IS AN INTEGER ACCUMULATOR (IA) WHICH IS CAPABLE OF
155: * HOLDING A SIGNED INTEGER VALUE (CFP$I WORDS LONG).
156: * REGISTER WC MAY OVERLAP THE INTEGER ACCUMULATOR (IA) IN
157: * SOME IMPLEMENTATIONS. THUS ANY OPERATION CHANGING THE
158: * VALUE IN WC LEAVES (IA) UNDEFINED AND VICE VERSA
159: * EXCEPT AS NOTED IN THE ABOVE RESTRICTION ON SIMPLE
160: * DUMP/RESTORE OPERATIONS.
161: *
162: *
163: *
164: * THERE IS A SINGLE REAL ACCUMULATOR (RA) WHICH CAN HOLD
165: * ANY REAL VALUE AND IS COMPLETELY SEPARATE FROM ANY OF
166: * THE OTHER REGISTERS OR PROGRAM ACCESSIBLE LOCATIONS.
167: *
168: *
169: *
170: * THE CODE POINTER REGISTER (CP) IS A SPECIAL INDEX
171: * REGISTER FOR USE IN IMPLEMENTATIONS OF INTERPRETORS.
172: * IT IS USED TO CONTAIN A PSEUDO-CODE POINTER AND CAN
173: * ONLY BE AFFECTED BY ICP, LCP, SCP AND LCW INSTRUCTIONS.
174: EJC
175: * SECTION 4 - THE STACK
176: *
177: * THE FOLLOWING NOTES ARE TO GUIDE BOTH IMPLEMENTORS OF
178: * SYSTEMS WRITTEN IN MINIMAL AND MINIMAL PROGRAMMERS IN
179: * DEALING WITH STACK MANIPULATION. IMPLEMENTATION OF A
180: * DOWNWARDS BUILDING STACK IS EASIEST AND IN GENERAL IS
181: * TO BE PREFERRED, IN WHICH CASE IT IS MERELY NECESSARY TO
182: * CONSIDER XT AS AN ALTERNATIVE NAME FOR XL.
183: *
184: * THE MINIMAL VIRTUAL MACHINE INCLUDES A STACK AND HAS
185: * OPERAND FORMATS -(XS) AND (XS)+ FOR PUSHING AND POPPING
186: * ITEMS WITH AN IMPLICATION THAT THE STACK BUILDS DOWN IN
187: * MEMORY (A D-STACK). HOWEVER ON SOME TARGET MACHINES IT IS
188: * BETTER FOR THE STACK TO BUILD UP (A U-STACK).
189: * A STACK ADDRESSED ONLY BY PUSH AND POP OPERATIONS CAN
190: * BUILD IN EITHER DIRECTION WITH NO COMPLICATION BUT
191: * SUCH A PURE SCHEME OF STACK ACCESS PROVES RESTRICTIVE.
192: * HENCE IT IS PERMITTED TO ACCESS BURIED ITEMS USING AN
193: * INTEGER OFFSET PAST THE INDEX REGISTER POINTING TO THE
194: * STACK TOP. ON TARGET MACHINES THIS OFFSET WILL BE
195: * POSITIVE/NEGATIVE FOR D-STACKS/U-STACKS AND THIS MUST
196: * BE ALLOWED FOR IN THE TRANSLATION.
197: * A FURTHER RESTRICTION IS THAT AT NO TIME MAY AN ITEM BE
198: * PLACED ABOVE THE STACK TOP. FOR SOME OPERATIONS THIS
199: * MAKES IT CONVENIENT TO ADVANCE THE STACK POINTER AND THEN
200: * ADDRESS ITEMS BELOW IT USING A SECOND INDEX REGISTER.
201: * THE PROBLEM OF SIGNED OFFSETS PAST SUCH A REGISTER THEN
202: * ARISES. TO DISTINGUISH STACK OFFSETS, WHICH IN SOME
203: * IMPLEMENTATIONS MAY BE NEGATIVE, FROM NON-STACK OFFSETS
204: * WHICH ARE INVARIABLY POSITIVE, XT, AN ALIAS OR
205: * SYNONYM FOR XL IS USED. FOR A U-STACK IMPLEMENTATION, THE
206: * MINIMAL TRANSLATOR SHOULD NEGATE THE SIGN OF OFFSETS
207: * APPLIED TO BOTH (XS) AND (XT).
208: * PROGRAMMERS SHOULD NOTE THAT SINCE XT IS NOT A
209: * SEPARATE REGISTER, XL SHOULD NOT BE USED IN CODE WHERE
210: * XT IS REFERENCED. OTHER MODIFICATIONS NEEDED IN U-STACK
211: * TRANSLATIONS ARE IN THE ADD, SUB, ICA, DCA OPCODES
212: * APPLIED TO XS, XT. FOR EXAMPLE
213: *
214: * MINIMAL D-STACK TRANS. U-STACK TRANS.
215: *
216: * MOV WA,-(XS) SBI XS,1 ADI XS,1
217: * STO WA,(XS) STO WA,(XS)
218: * MOV (XT)+,WC LOD WC,(XL) LOD WC,(XL)
219: * ADI XL,1 SBI XL,1
220: * ADD =SEVEN,XS ADI XS,7 SBI XS,7
221: * MOV 2(XT),WA LOD WA,2(XL) LOD WA,-2(XL)
222: * ICA XS ADI XS,1 SBI XS,1
223: *
224: * NOTE THAT FORMS SUCH AS
225: * MOV -(XS),WA
226: * ADD WA,(XS)+
227: * ARE ILLEGAL, SINCE THEY ASSUME INFORMATION STORAGE
228: * ABOVE THE STACK TOP.
229: EJC
230: * SECTION 5 - INTERNAL CHARACTER SET
231: *
232: * THE INTERNAL CHARACTER SET IS REPRESENTED BY A SET OF
233: * CONTIGUOUS CODES FROM 0 TO CFP$A-1. THE CODES FOR THE
234: * DIGITS 0-9 MUST BE CONTIGUOUS AND IN SEQUENCE. OTHER
235: * THAN THIS, THERE ARE NO RESTRAINTS.
236: *
237: * THE FOLLOWING SYMBOLS ARE AUTOMATICALLY DEFINED TO HAVE
238: * THE VALUE OF THE CORRESPONDING INTERNAL CHARACTER CODE.
239: *
240: * CH$LA LETTER A
241: * CH$LB LETTER B
242: * . .
243: * CH$L$ LETTER Z
244: *
245: * CH$D0 DIGIT 0
246: * . .
247: * CH$D9 DIGIT 9
248: *
249: * CH$AM AMPERSAND
250: * CH$AS ASTERISK
251: * CH$AT AT
252: * CH$BB LEFT BRACKET
253: * CH$BL BLANK
254: * CH$BR VERTICAL BAR
255: * CH$CL COLON
256: * CH$CM COMMA
257: * CH$DL DOLLAR SIGN
258: * CH$DT DOT (PERIOD)
259: * CH$DQ DOUBLE QUOTE
260: * CH$EQ EQUAL SIGN
261: * CH$EX EXCLAMATION MARK
262: * CH$MN MINUS
263: * CH$NM NUMBER SIGN
264: * CH$NT NOT
265: * CH$PC PERCENT
266: * CH$PL PLUS
267: * CH$PP LEFT PAREN
268: * CH$RB RIGHT BRACKET
269: * CH$RP RIGHT PAREN
270: * CH$QU QUESTION MARK
271: * CH$SL SLASH
272: * CH$SM SEMI-COLON
273: * CH$SQ SINGLE QUOTE
274: * CH$UN UNDERLINE
275: *
276: * THE FOLLOWING OPTIONAL SYMBOLS ARE INCORPORATED
277: * BY DEFINING THE CONDITIONAL ASSEMBLY SYMBOL NAMED.
278: *
279: * 26 SHIFTED LETTERS INCORPORATED BY DEFINING .CASL
280: *
281: * CH$$A SHIFTED A
282: * CH$$B SHIFTED B
283: * . .
284: * CH$$$ SHIFTED Z
285: *
286: * CH$HT HORIZONTAL TAB - DEFINE .CAHT
287: * CH$VT VERTICAL TAB - DEFINE .CAVT
288: EJC
289: *
290: * SECTION 6 - CONDITIONAL ASSEMBLY FEATURES
291: *
292: * SOME FEATURES OF THE INTERPRETER ARE APPLICABLE TO ONLY
293: * CERTAIN TARGET MACHINES. THEY MAY BE INCORPORATED OR
294: * OMITTED BY USE OF CONDITIONAL ASSEMBLY. THE FULL
295: * FORM OF A CONDITION IS -
296: * .IF CONDITIONAL ASSEMBLY SYMBOL (CAS)
297: * .THEN
298: * MINIMAL STATEMENTS1 (MS1)
299: * .ELSE
300: * MINIMAL STATEMENTS2 (MS2)
301: * .FI
302: * THE FOLLOWING RULES APPLY
303: * 1. THE DIRECTIVES .IF, .THEN, .ELSE, .FI MUST
304: * START IN COLUMN 1.
305: * 2. THE CONDITIONAL ASSEMBLY SYMBOL MUST START WITH A
306: * DOT IN COLUMN 8 FOLLOWED BY 4 LETTERS OR DIGITS E.G.
307: * .CA$1
308: * 3. .THEN IS REDUNDANT AND MAY BE OMITTED IF WISHED.
309: * 4. MS1, MS2 ARE ARBITRARY SEQUENCES OF MINIMAL
310: * STATEMENTS EITHER OF WHICH MAY BE NULL.
311: * 5. IF MS2 IS OMITTED, .ELSE MAY ALSO BE OMITTED.
312: * 6. .FI IS REQUIRED.
313: * 7. CONDITIONS MAY BE NESTED TO A DEPTH DETERMINED
314: * BY THE TRANSLATOR (NOT LESS THAN 20, SAY).
315: *
316: * SELECTION OF THE ALTERNATIVES MS1, MS2 IS BY MEANS OF THE
317: * DEFINE AND UNDEFINE DIRECTIVES OF FORM -
318: * .DEF CAS
319: * .UNDEF CAS
320: * WHICH OBEY RULES 1. AND 2. ABOVE AND MAY OCCUR AT ANY
321: * POINT IN A MINIMAL PROGRAM, INCLUDING WITHIN A CONDITION.
322: * MULTIPLY DEFINING A SYMBOL IS AN ERROR.
323: * UNDEFINING A SYMBOL WHICH IS NOT DEFINED IS NOT AN ERROR.
324: *
325: * THE EFFECT IS THAT IF A SYMBOL IS CURRENTLY DEFINED,
326: * THEN IN ANY CONDITION DEPENDING ON IT, MS1 WILL BE
327: * PROCESSED AND MS2 OMITTED. CONVERSELY IF IT IS UNDEFINED,
328: * MS1 WILL BE OMITTED AND MS2 PROCESSED.
329: EJC
330: *
331: * SECTION 7 - OPERAND FORMATS
332: *
333: * THE FOLLOWING SECTION DESCRIBES THE VARIOUS POSSIBILITIES
334: * FOR OPERANDS OF INSTRUCTIONS AND ASSEMBLY OPERATIONS.
335: *
336: * 01 INT UNSIGNED INTEGER LE CFP$M
337: * 02 DLBL SYMBOL DEFINED IN DEFINITIONS SEC
338: * 03 WLBL LABEL IN WORKING STORAGE SECTION
339: * 04 CLBL LABEL IN CONSTANT SECTION
340: * 05 ELBL PROGRAM SECTION ENTRY LABEL
341: * 06 PLBL PROGRAM SECTION LABEL (NON-ENTRY)
342: * 07 X ONE OF THE THREE INDEX REGISTERS
343: * 08 W ONE OF THE THREE WORK REGISTERS
344: * 09 (X) LOCATION INDEXED BY X
345: * 10 (X)+ LIKE (X) BUT POST INCREMENT X
346: * 11 -(X) LIKE (X) BUT PREDECREMENT X
347: * 12 INT(X) LOCATION INT WORDS BEYOND ADDR IN X
348: * 13 DLBL(X) LOCATION DLBL WORDS PAST ADDR IN X
349: * 14 CLBL(X) LOCATION (X) BYTES BEYOND CLBL
350: * 15 WLBL(X) LOCATION (X) BYTES BEYOND WLBL
351: * 16 INTEGER SIGNED INTEGER (DIC)
352: * 17 REAL SIGNED REAL (DRC)
353: * 18 =DLBL LOCATION CONTAINING DAC DLBL
354: * 19 *DLBL LOCATION CONTAINING DAC CFP$B*DLBL
355: * 20 =WLBL LOCATION CONTAINING DAC WLBL
356: * 21 =CLBL LOCATION CONTAINING DAC CLBL
357: * 22 =ELBL LOCATION CONTAINING DAC ELBL
358: * 23 PNAM PROCEDURE LABEL (ON PRC INSTRUC)
359: * 24 EQOP OPERAND FOR EQU INSTRUCTION
360: * 25 PTYP PROCEDURE TYPE (SEE PRC)
361: * 26 TEXT ARBITRARY TEXT (ERB,ERR,TTL)
362: * 27 DTEXT DELIMITED TEXT STRING (DTC)
363: *
364: * THE NUMBERS IN THE ABOVE LIST ARE USED IN SUBSEQUENT
365: * DESCRIPTION AND IN SOME OF THE MINIMAL TRANSLATORS.
366: EJC
367: *
368: * OPERAND FORMATS (CONTINUED)
369: *
370: * THE FOLLOWING SPECIAL SYMBOLS REFER TO A COLLECTION OF
371: * THE LISTED POSSIBILITIES
372: *
373: * VAL 01,02 PREDEFINED VALUE
374: *
375: * VAL IS USED TO REFER TO A PREDEFINED ONE WORD
376: * INTEGER VALUE IN THE RANGE 0 LE N LE CFP$M.
377: *
378: * REG 07,08 REGISTER
379: *
380: * REG IS USED TO DESCRIBE AN OPERAND WHICH CAN BE
381: * ANY OF THE REGISTERS (XL,XR,XS,XT,WA,WB,WC). SUCH
382: * AN OPERAND CAN HOLD A ONE WORD INTEGER (ADDRESS).
383: *
384: * OPC 09,10,11 CHARACTER
385: *
386: * OPC IS USED TO DESIGNATE A SPECIFIC CHARACTER
387: * OPERAND FOR USE IN THE LCH AND SCH INSTRUCTIONS.
388: * THE INDEX REGISTER REFERENCED MUST BE EITHER XR OR
389: * XL (NOT XS,XT). SEE SECTION ON CHARACTER OPERATIONS.
390: *
391: * OPS 03,04,09,12,13,14,15 MEMORY REFERENCE
392: *
393: * OPS IS USED TO DESCRIBE AN OPERAND WHICH IS IN
394: * MEMORY. THE OPERAND MAY BE ONE OR MORE WORDS LONG
395: * DEPENDING ON THE DATA TYPE. IN THE CASE OF MULTIWORD
396: * OPERANDS, THE ADDRESS GIVEN IS THE FIRST WORD.
397: *
398: * OPW AS FOR OPS + 08,10,11 FULL WORD
399: *
400: * OPW IS USED TO REFER TO AN OPERAND WHOSE CAPACITY IS
401: * THAT OF A FULL MEMORY WORD. OPW INCLUDES ALL THE
402: * POSSIBILITIES FOR OPS (THE REFERENCED WORD IS USED)
403: * PLUS THE USE OF ONE OF THE THREE WORK REGISTERS
404: * (WA,WB,WC). IN ADDITION, THE FORMATS (X)+ AND -(X)
405: * ALLOW INDEXED OPERATIONS IN WHICH THE INDEX REGISTER
406: * IS POPPED BY ONE WORD AFTER THE REFERENCE (X)+,
407: * OR PUSHED BY ONE WORD BEFORE THE REFERENCE -(X)
408: * THESE LATTER TWO FORMATS PROVIDE A FACILITY FOR
409: * MANIPULATION OF STACKS. THE FORMAT DOES NOT IMPLY
410: * A PARTICULAR DIRECTION IN WHICH STACKS MUST BUILD -
411: * IT IS USED FOR COMPACTNESS. NOTE THAT THERE IS A
412: * RESTRICTION WHICH DISALLOWS AN INSTRUCTION TO USE
413: * AN INDEX REGISTER IN ONE OF THESE FORMATS
414: * IN SOME OTHER MANNER IN THE SAME INSTRUCTION.
415: * E.G. MOV XL,(XL)+ IS ILLEGAL.
416: * THE FORMATS -(X) AND (X)+ MAY ALSO BE USED IN
417: * PRE-DECREMENTATION, POST-INCREMENTATION TO ACCESS
418: * THE ADJACENT CHARACTER OF A STRING.
419: EJC
420: *
421: * OPERAND FORMATS (CONTINUED)
422: *
423: * OPN AS FOR OPW + 07 ONE WORD INTEGER
424: *
425: * OPN IS USED TO REPRESENT AN OPERAND LOCATION WHICH
426: * CAN CONTAIN A ONE WORD INTEGER (E.G. AN ADDRESS).
427: * THIS INCLUDES ALL THE POSSIBILITIES FOR OPW PLUS
428: * THE USE OF ONE OF THE INDEX REGISTERS (XL,XR,XT,
429: * XS). THE RANGE OF INTEGER VALUES IS 0 LE N LE CFP$M.
430: *
431: * OPV AS FOR OPN + 18-22 ONE WORD INTEGER VALUE
432: *
433: * OPV IS USED FOR AN OPERAND WHICH CAN YIELD A ONE
434: * WORD INTEGER VALUE (E.G. AN ADDRESS). IT INCLUDES
435: * ALL THE POSSIBILITIES FOR OPN (THE CURRENT VALUE OF
436: * THE LOCATION IS USED) PLUS THE USE OF LITERALS. NOTE
437: * THAT ALTHOUGH THE LITERAL FORMATS ARE DESCRIBED IN
438: * TERMS OF A REFERENCE TO A LOCATION CONTAINING AN
439: * ADDRESS CONSTANT, THIS LOCATION MAY NOT ACTUALLY
440: * EXIST IN SOME IMPLEMENTATIONS SINCE ONLY THE VALUE
441: * IS REQUIRED. A RESTRICTION IS PLACED ON LITERALS
442: * WHICH MAY CONSIST ONLY OF DEFINED SYMBOLS AND
443: * CERTAIN LABELS. CONSEQUENTLY SMALL INTEGERS TO BE
444: * USED AS LITERALS MUST BE PRE-DEFINED, A DISCIPLINE
445: * AIDING PROGRAM MAINTENANCE AND REVISION.
446: *
447: * ADDR 01,02,03,04,05 ADDRESS
448: *
449: * ADDR IS USED TO DESCRIBE AN EXPLICIT ADDRESS VALUE
450: * (ONE WORD INTEGER VALUE) FOR USE WITH DAC.
451: *
452: *
453: * ****************************************************
454: * * IN THE FOLLOWING DESCRIPTIONS THE USAGE -- *
455: * * (XL),(XR), ... ,(IA) *
456: * * IN THE DESCRIPTIVE TEXT SIGNIFIES THE +
457: * * CONTENTS OF THE STATED REGISTER. *
458: * ****************************************************
459: EJC
460: *
461: * SECTION 8 - LIST OF INSTRUCTION MNEMONICS
462: *
463: * THE FOLLOWING LIST INCLUDES ALL INSTRUCTION AND
464: * ASSEMBLY OPERATION MNEMONICS IN ALPHABETICAL ORDER.
465: * THE MNEMONICS ARE PRECEDED BY A NUMBER IDENTIFYING
466: * THE FOLLOWING SECTION WHERE THE INSTRUCTION IS DESCRIBED.
467: * A STAR (*) IS APPENDED TO THE MNEMONIC IF THE LAST
468: * OPERAND MAY OPTIONALLY BE OMITTED.
469: * SEE SECTION -15- FOR DETAILS OF STATEMENT FORMAT AND
470: * COMMENT CONVENTIONS.
471: *
472: * 2.1 ADD OPV,OPN ADD ADDRESS
473: * 4.2 ADI OPS ADD INTEGER
474: * 5.3 ADR OPS ADD REAL
475: * 7.1 ANB OPW,W AND BIT STRING
476: * 2.17 AOV OPV,OPN,PLBL ADD ADDRESS, FAIL IF OVERFLOW
477: * 2.16 BCT W,PLBL BRANCH AND COUNT
478: * 2.5 BEQ OPN,OPV,PLBL BRANCH IF ADDRESS EQUAL
479: * 2.8 BGE OPN,OPV,PLBL BRANCH IF ADDRESS GREATER OR EQUL
480: * 2.7 BGT OPN,OPV,PLBL BRANCH IF ADDRESS GREATER
481: * 2.12 BHI OPN,OPV,PLBL BRANCH IF ADDRESS HIGH
482: * 2.10 BLE OPN,OPV,PLBL BRANCH IF ADDRESS LESS OR EQUAL
483: * 2.11 BLO OPN,OPV,PLBL BRANCH IF ADDRESS LOW
484: * 2.9 BLT OPN,OPV,PLBL BRANCH IF ADDRESS LESS THAN
485: * 2.6 BNE OPN,OPV,PLBL BRANCH IF ADDRESS NOT EQUAL
486: * 2.13 BNZ OPN,PLBL BRANCH IF ADDRESS NON-ZERO
487: * 1.2 BRN PLBL BRANCH UNCONDITIONAL
488: * 1.7 BRI OPN BRANCH INDIRECT
489: * 1.3 BSW* X,VAL,PLBL BRANCH ON SWITCH VALUE
490: * 8.2 BTW REG CONVERT BYTES TO WORDS
491: * 2.14 BZE OPN,PLBL BRANCH IF ADDRESS ZERO
492: * 6.6 CEQ OPW,OPW,PLBL BRANCH IF CHARACTERS EQUAL
493: * 10.1 CHK CHECK STACK OVERFLOW
494: * 7.4 CMB W COMPLEMENT BIT STRING
495: * 6.8 CMC PLBL,PLBL COMPARE CHARACTER STRINGS
496: * 6.7 CNE OPW,OPW,PLBL BRANCH IF CHARACTERS NOT EQUAL
497: * 6.5 CSC X COMPLETE STORE CHARACTERS
498: * 8.8 CTB W,VAL CONVERT CHARACTER COUNT TO BYTES
499: * 8.7 CTW W,VAL CONVERT CHARACTER COUNT TO WORDS
500: * 8.10 CVD CONVERT BY DIVISION
501: * 8.9 CVM PLBL CONVERT BY MULTIPLICATION
502: * 11.1 DAC ADDR DEFINE ADDRESS CONSTANT
503: * 11.5 DBC VAL DEFINE BIT STRING CONSTANT
504: * 2.4 DCA OPN DECREMENT ADDRESS BY ONE WORD
505: * 1.17 DCV OPN DECREMENT VALUE BY ONE
506: * 11.2 DIC INTEGER DEFINE INTEGER CONSTANT
507: EJC
508: *
509: * ALPHABETICAL LIST OF MNEMONICS (CONTINUED)
510: *
511: * 11.3 DRC REAL DEFINE REAL CONSTANT
512: * 11.4 DTC DTEXT DEFINE TEXT (CHARACTER) CONSTANT
513: * 4.5 DVI OPS DIVIDE INTEGER
514: * 5.6 DVR OPS DIVIDE REAL
515: * 13.1 EJC EJECT ASSEMBLY LISTING
516: * 14.2 END END OF ASSEMBLY
517: * 1.13 ENP DEFINE END OF PROCEDURE
518: * 1.6 ENT* VAL DEFINE ENTRY POINT
519: * 12.1 EQU EQOP DEFINE SYMBOLIC VALUE
520: * 1.15 ERB INT,TEXT ASSEMBLE ERROR CODE AND BRANCH
521: * 1.14 ERR INT,TEXT ASSEMBLE ERROR CODE
522: * 1.5 ESW END OF SWITCH LIST FOR BSW
523: * 1.12 EXI* INT EXIT FROM PROCEDURE
524: * 12.2 EXP DEFINE EXTERNAL PROCEDURE
525: * 2.3 ICA OPN INCREMENT ADDRESS BY ONE WORD
526: * 3.4 ICP INCREMENT CODE POINTER
527: * 1.16 ICV OPN INCREMENT VALUE BY ONE
528: * 4.11 IEQ PLBL JUMP IF INTEGER ZERO
529: * 1.4 IFF VAL,PLBL SPECIFY BRANCH FOR BSW
530: * 4.12 IGE PLBL JUMP IF INTEGER NON-NEGATIVE
531: * 4.13 IGT PLBL JUMP IF INTEGER POSITIVE
532: * 4.14 ILE PLBL JUMP IF INTEGER NEGATIVE OR ZERO
533: * 4.15 ILT PLBL JUMP IF INTEGER NEGATIVE
534: * 4.16 INE PLBL JUMP IF INTEGER NON-ZERO
535: * 4.9 INO PLBL JUMP IF NO INTEGER OVERFLOW
536: * 12.3 INP PTYP,INT INTERNAL PROCEDURE
537: * 12.4 INR INTERNAL ROUTINE
538: * 4.10 IOV PLBL JUMP IF INTEGER OVERFLOW
539: * 8.5 ITR CONVERT INTEGER TO REAL
540: * 1.9 JSR PNAM CALL PROCEDURE
541: * 6.3 LCH REG,OPC LOAD CHARACTER
542: * 2.15 LCT W,OPV LOAD COUNTER FOR LOOP
543: * 3.1 LCP REG LOAD CODE POINTER REGISTER
544: * 3.3 LCW REG LOAD NEXT CODE WORD
545: * 4.1 LDI OPS LOAD INTEGER
546: * 5.1 LDR OPS LOAD REAL
547: * 1.8 LEI X LOAD ENTRY POINT ID
548: * 7.6 LSH W,VAL LEFT SHIFT BIT STRING
549: * 7.8 LSX W,(X) LEFT SHIFT INDEXED
550: * 8.4 MFI* OPN,PLBL CONVERT (IA) TO ADDRESS VALUE
551: * 4.3 MLI OPS MULTIPLY INTEGER
552: * 5.5 MLR OPS MULTIPLY REAL
553: * 1.19 MNZ OPN MOVE NON-ZERO
554: * 1.1 MOV OPV,OPN MOVE
555: * 8.3 MTI OPN MOVE ADDRESS VALUE TO (IA)
556: * 9.1 MVC MOVE CHARACTERS
557: * 9.2 MVW MOVE WORDS
558: * 9.3 MWB MOVE WORDS BACKWARDS
559: * 4.8 NGI NEGATE INTEGER
560: EJC
561: *
562: * ALPHABETICAL LIST OF MNEMONICS (CONTINUED)
563: *
564: * 5.9 NGR NEGATE REAL
565: * 7.9 NZB W,PLBL JUMP IF NOT ALL ZERO BITS
566: * 7.2 ORB OPW,W OR BIT STRINGS
567: * 6.1 PLC* X,OPV PREPARE TO LOAD CHARACTERS
568: * 1.10 PPM* PLBL PROVIDE PROCEDURE EXIT PARAMETER
569: * 1.11 PRC PTYP,VAL DEFINE START OF PROCEDURE
570: * 6.2 PSC* X,OPV PREPARE TO STORE CHARACTERS
571: * 5.10 REQ PLBL JUMP IF REAL ZERO
572: * 5.11 RGE PLBL JUMP IF REAL POSITIVE OR ZERO
573: * 5.12 RGT PLBL JUMP IF REAL POSITIVE
574: * 5.13 RLE PLBL JUMP IF REAL NEGATIVE OR ZERO
575: * 5.14 RLT PLBL JUMP IF REAL NEGATIVE
576: * 4.6 RMI OPS REMAINDER INTEGER
577: * 5.15 RNE PLBL JUMP IF REAL NON-ZERO
578: * 5.8 RNO PLBL JUMP IF NO REAL OVERFLOW
579: * 5.7 ROV PLBL JUMP IF REAL OVERFLOW
580: * 7.5 RSH W,VAL RIGHT SHIFT BIT STRING
581: * 7.7 RSX W,(X) RIGHT SHIFT INDEXED
582: * 8.6 RTI* PLBL CONVERT REAL TO INTEGER
583: * 1.22 RTN DEFINE START OF ROUTINE
584: * 4.4 SBI OPS SUBTRACT INTEGER
585: * 5.4 SBR OPS SUBTRACT REALS
586: * 6.4 SCH REG,OPC STORE CHARACTER
587: * 3.2 SCP REG STORE CODE POINTER
588: * 14.1 SEC DEFINE START OF ASSEMBLY SECTION
589: * 1.20 SSL OPW SUBROUTINE STACK LOAD
590: * 1.21 SSS OPW SUBROUTINE STACK STORE
591: * 4.7 STI OPS STORE INTEGER
592: * 5.2 STR OPS STORE REAL
593: * 2.2 SUB OPV,OPN SUBTRACT ADDRESS
594: * 6.9 TRC TRANSLATE CHARACTER STRING
595: * 13.2 TTL TEXT SUPPLY ASSEMBLY TITLE
596: * 8.1 WTB REG CONVERT WORDS TO BYTES
597: * 7.3 XOB OPW,W EXCLUSIVE OR BIT STRINGS
598: * 1.18 ZER OPN ZEROISE INTEGER LOCATION
599: * 7.11 ZGB OPN ZEROISE GARBAGE BITS
600: * 7.10 ZRB W,PLBL JUMP IF ALL ZERO BITS
601: EJC
602: *
603: * SECTION 9 - MINIMAL INSTRUCTIONS
604: *
605: * THE FOLLOWING DESCRIPTIONS ASSUME THE DEFINITIONS -
606: *
607: * ZEROE EQU 0
608: * UNITY EQU 1
609: *
610: * -1- BASIC INSTRUCTION SET
611: *
612: * 1.1 MOV OPV,OPN MOVE ONE WORD VALUE
613: *
614: * MOV CAUSES THE VALUE OF OPERAND OPV TO BE SET AS
615: * THE NEW CONTENTS OF OPERAND LOCATION OPN. IN THE
616: * CASE WHERE OPN IS NOT AN INDEX REGISTER, ANY VALUE
617: * WHICH CAN NORMALLY OCCUPY A MEMORY WORD (INCLUDING
618: * A PART OF A MULTIWORD REAL OR INTEGER VALUE)
619: * CAN BE TRANSFERRED USING MOV. IF THE TARGET LOCATION
620: * OPN IS AN INDEX REGISTER, THEN OPV MUST SPECIFY AN
621: * APPROPRIATE ONE WORD VALUE OR OPERAND CONTAINING
622: * SUCH AN APPROPRIATE VALUE.
623: *
624: * 1.2 BRN PLBL UNCONDITIONAL BRANCH
625: *
626: * BRN CAUSES CONTROL TO BE PASSED TO THE INDICATED
627: * LABEL IN THE PROGRAM SECTION.
628: *
629: * 1.3 BSW X,VAL,PLBL BRANCH ON SWITCH VALUE
630: * 1.4 IFF VAL,PLBL PROVIDE BRANCH FOR SWITCH
631: * IFF VAL,PLBL ...
632: * ...
633: * ...
634: * 1.5 ESW END OF BRANCH SWITCH TABLE
635: *
636: * BSW,IFF,ESW PROVIDE A CAPABILITY FOR A SWITCHED
637: * BRANCH SIMILAR TO A FORTRAN COMPUTED GOTO. THE
638: * VAL ON THE BSW INSTRUCTION IS THE MAXIMUM NUMBER
639: * OF BRANCHES. THE VALUE IN X RANGES FROM ZERO UP TO
640: * BUT NOT INCLUDING THIS MAXIMUM. EACH IFF PROVIDES A
641: * BRANCH. VAL MUST BE LESS THAN THAT GIVEN ON THE BSW
642: * AND CONTROL GOES TO PLBL IF THE VALUE IN X MATCHES.
643: * IF THE VALUE IN X DOES NOT CORRESPOND TO ANY OF THE
644: * IFF ENTRIES, THEN CONTROL PASSES TO THE PLBL ON THE
645: * BSW. THIS PLBL OPERAND MAY BE OMITTED IF THERE ARE
646: * NO VALUES MISSING FROM THE LIST.
647: *
648: * IFF AND ESW MAY ONLY BE USED IN THIS CONTEXT.
649: * EXECUTION OF BSW MAY DESTROY THE CONTENTS OF X.
650: * THE IFF ENTRIES MAY BE IN ANY ORDER AND SINCE
651: * A TRANSLATOR MAY THUS NEED TO STORE AND SORT THEM,
652: * THE COMMENT FIELD IS RESTRICTED IN LENGTH (SEC 11).
653: EJC
654: *
655: * -1- BASIC INSTRUCTIONS (CONTINUED)
656: *
657: * 1.6 ENT VAL DEFINE PROGRAM ENTRY POINT
658: *
659: * THE SYMBOL APPEARING IN THE LABEL FIELD IS DEFINED
660: * TO BE A PROGRAM ENTRY POINT WHICH CAN SUBSEQUENTLY
661: * BE USED IN CONJUNCTION WITH THE BRI INSTRUCTION,
662: * WHICH PROVIDES THE ONLY MEANS OF ENTERING THE
663: * CODE. IT IS ILLEGAL TO FALL INTO CODE
664: * IDENTIFIED BY AN ENTRY POINT. THE
665: * ENTRY SYMBOL IS ASSIGNED AN ADDRESS WHICH NEED NOT
666: * BE A MULTIPLE OF CFP$B BUT WHICH MUST BE IN THE
667: * RANGE 0 LE CFP$M AND THE ADDRESS MUST NOT LIE WITHIN
668: * THE ADDRESS RANGE OF THE ALLOCATED DATA AREA.
669: * FURTHERMORE, ADDRESSES OF SUCCESSIVE ENTRY POINTS
670: * MUST BE ASSIGNED IN SOME ASCENDING SEQUENCE SO
671: * THAT THE ADDRESS COMPARISON INSTRUCTIONS CAN BE
672: * USED TO TEST THE ORDER IN WHICH TWO ENTRY POINTS
673: * OCCUR. THE SYMBOL VAL GIVES AN IDENTIFYING VALUE
674: * TO THE ENTRY POINT WHICH CAN BE ACCESSED WITH THE
675: * LEI INSTRUCTION.
676: * NOTE - SUBJECT TO THE RESTRICTION BELOW, VAL MAY
677: * BE OMITTED IF NO SUCH IDENTIFICATION IS NEEDED I.E.
678: * IF NO LEI REFERENCES THE ENTRY POINT. FOR THIS
679: * CASE, A TRANSLATION OPTIMISATION IS POSSIBLE IN
680: * WHICH NO MEMORY NEED BE RESERVED FOR A NULL
681: * IDENTIFICATION WHICH IS NEVER TO BE REFERENCED, BUT
682: * ONLY PROVIDED THIS IS DONE SO AS NOT TO INTERFERE
683: * WITH THE STRICTLY ASCENDING SEQUENCE OF ENTRY POINT
684: * ADDRESSES. TO SIMPLIFY THIS OPTIMISATION FOR ALL
685: * IMPLEMENTORS, THE FOLLOWING RESTRICTION IS OBSERVED
686: * VAL MAY ONLY BE OMITTED IF THE ENTRY POINT IS
687: * SEPARATED FROM A FOLLOWING ENTRY POINT BY A
688: * NON-NULL MINIMAL CODE SEQUENCE.
689: * ENTRY POINT ADDRESSES ARE ACCESSIBLE ONLY BY USE OF
690: * LITERALS (=ELBL, SECTION 7) OR DAC CONSTANTS
691: * (SECTION 8-11.1).
692: *
693: * 1.7 BRI OPN BRANCH INDIRECT
694: *
695: * OPN CONTAINS THE ADDRESS OF A PROGRAM ENTRY POINT
696: * (SEE ENT). CONTROL IS PASSED TO THE EXECUTABLE
697: * CODE STARTING AT THE ENTRY POINT ADDRESS. OPN IS
698: * LEFT UNCHANGED.
699: *
700: * 1.8 LEI X LOAD ENTRY POINT IDENTIFICATION
701: *
702: * X CONTAINS THE ADDRESS OF AN ENTRY POINT FOR WHICH
703: * AN IDENTIFYING VALUE WAS GIVEN ON THE THE ENT LINE.
704: * LEI REPLACES THE CONTENTS OF X BY THIS VALUE.
705: EJC
706: *
707: * -1- BASIC INSTRUCTIONS (CONTINUED)
708: *
709: * 1.9 JSR PNAM CALL PROCEDURE PNAM
710: * 1.10 PPM PLBL PROVIDE EXIT PARAMETER
711: * PPM PLBL ...
712: * ...
713: * PPM PLBL ...
714: *
715: * JSR CAUSES CONTROL TO BE PASSED TO THE NAMED
716: * PROCEDURE. PNAM IS THE LABEL ON A PRC STATEMENT
717: * ELSEWHERE IN THE PROGRAM SECTION (SEE PRC)
718: * OR HAS BEEN DEFINED USING AN EXP INSTRUCTION.
719: * THE PPM EXIT PARAMETERS FOLLOWING THE CALL GIVE
720: * NAMES OF PROGRAM LOCATIONS (PLBL-S) TO WHICH
721: * ALTERNATIVE EXI RETURNS OF THE CALLED PROCEDURE MAY
722: * PASS CONTROL. THEY MAY OPTIONALLY BE REPLACED BY
723: * ERROR RETURNS (SEE ERR). THE NUMBER OF EXIT
724: * PARAMETERS FOLLOWING A JSR MUST EQUAL THE INT IN THE
725: * PROCEDURE DEFINITION. THE OPERAND OF PPM MAY BE
726: * OMITTED IF THE CORRESPONDING EXI RETURN IS CERTAIN
727: * NOT TO BE TAKEN.
728: *
729: * 1.11 PRC PTYP,INT DEFINE START OF PROCEDURE
730: *
731: * THE SYMBOL APPEARING IN THE LABEL FIELD IS DEFINED
732: * TO BE THE NAME OF A PROCEDURE FOR USE WITH JSR.
733: * A PROCEDURE IS A CONTIGUOUS SECTION OF INSTRUCTIONS
734: * TO WHICH CONTROL MAY BE PASSED WITH A JSR
735: * INSTRUCTION. THIS IS THE ONLY WAY IN WHICH THE
736: * INSTRUCTIONS IN A PROCEDURE MAY BE EXECUTED. IT IS
737: * NOT PERMITTED TO FALL INTO A PROCEDURE.
738: * ALL PROCEDURES SHOULD BE NAMED IN SECTION 0
739: * INP STATEMENTS.
740: *
741: * INT IS THE NUMBER OF EXIT PARAMETERS (PPM-S) TO
742: * BE USED IN JSR CALLS.
743: *
744: * THERE ARE THREE POSSIBILITIES FOR PTYP, EACH
745: * CONSISTING OF A SINGLE LETTER AS FOLLOWS.
746: *
747: * R RECURSIVE
748: *
749: * THE RETURN POINT (ONE OR MORE WORDS) IS STORED ON
750: * THE STACK AS THOUGH ONE OR MORE MOV ..,-(XS)
751: * INSTRUCTIONS WERE EXECUTED.
752: EJC
753: *
754: * -1- BASIC INSTRUCTIONS (CONTINUED)
755: *
756: * N NON-RECURSIVE
757: *
758: * THE RETURN POINT IS TO BE STORED EITHER
759: * (1) IN A LOCAL STORAGE WORD ASSOCIATED
760: * WITH THE PROCEDURE AND NOT DIRECTLY
761: * AVAILABLE TO THE PROGRAM IN ANY OTHER MANNER OR
762: * (2) ON A SUBROUTINE LINK STACK QUITE DISTINCT FROM
763: * THE MINIMAL STACK ADDRESSED BY XS.
764: * IT IS AN ERROR TO USE THE STACK FOR N-LINKS, SINCE
765: * PROCEDURE PARAMETERS OR RESULTS MAY BE PASSED VIA
766: * THE STACK.
767: * IF METHOD (2) IS USED FOR LINKS, ERROR EXITS
768: * (ERB,ERR) FROM A PROCEDURE WILL NECESSITATE LINK
769: * STACK RESETTING. THE SSL AND SSS ORDERS PROVIDED
770: * FOR THIS MAY BE REGARDED AS NO-OPS FOR
771: * IMPLEMENTATIONS USING METHOD (1).
772: *
773: * E EITHER
774: *
775: * THE RETURN POINT MAY BE STORED IN EITHER MANNER
776: * ACCORDING TO EFFICIENCY REQUIREMENTS OF THE ACTUAL
777: * PHYSICAL MACHINE USED FOR THE IMPLEMENTATION. NOTE
778: * THAT PROGRAMMING OF E TYPE PROCEDURES MUST BE
779: * INDEPENDENT OF THE ACTUAL IMPLEMENTATION.
780: *
781: * THE ACTUAL FORM OF THE RETURN POINT IS UNDEFINED.
782: * HOWEVER, EACH WORD STORED ON THE STACK FOR AN
783: * R-TYPE CALL MUST MEET THE FOLLOWING REQUIREMENTS.
784: *
785: * 1) IT CAN BE HANDLED AS AN ADDRESS
786: * AND PLACED IN AN INDEX REGISTER.
787: *
788: * 2) WHEN USED AS AN OPERAND IN AN
789: * ADDRESS COMPARISON INSTRUCTION, IT
790: * MUST NOT APPEAR TO LIE WITHIN
791: * THE ALLOCATED DATA AREA.
792: *
793: * 3) IT IS NOT REQUIRED TO APPEAR
794: * TO LIE WITHIN THE PROGRAM SECTION.
795: EJC
796: *
797: * -1- BASIC INSTRUCTIONS (CONTINUED)
798: *
799: * 1.12 EXI INT EXIT FROM PROCEDURE
800: *
801: * THE PPM AND ERR PARAMETERS FOLLOWING A JSR ARE
802: * NUMBERED STARTING FROM 1. EXI INT CAUSES CONTROL
803: * TO BE RETURNED TO THE INT-TH SUCH PARAM. EXI 1 GIVES
804: * CONTROL TO THE PLBL OF THE FIRST PPM AFTER THE JSR.
805: * IF INT IS OMITTED, CONTROL IS PASSED BACK PAST THE
806: * LAST EXIT PARAMETER (OR PAST THE JSR IF THERE ARE
807: * NONE). FOR R AND E TYPE PROCEDURES, THE
808: * STACK POINTER XS MUST BE SET TO ITS APPROPRIATE
809: * ENTRY VALUE BEFORE EXECUTING AN EXI INSTRUCTION.
810: * IN THIS CASE, EXI REMOVES RETURN POINTS FROM THE
811: * STACK IF ANY ARE STORED THERE SO THAT THE STACK
812: * POINTER IS RESTORED TO ITS CALLING VALUE.
813: *
814: * 1.13 ENP DEFINE END OF PROCEDURE BODY
815: *
816: * ENP DELIMITS A PROCEDURE BODY AND MAY NOT ACTUALLY
817: * BE EXECUTED, HENCE IT MUST HAVE NO LABEL.
818: *
819: * 1.14 ERR INT,TEXT PROVIDE ERROR RETURN
820: *
821: * ERR MAY REPLACE AN EXIT PARAMETER (PPM) IN
822: * ANY PROCEDURE CALL. THE INT ARGUMENT IS A UNIQUE
823: * ERROR CODE IN 0 TO 899.
824: * THE TEXT SUPPLIED AS THE OTHER OPERAND IS
825: * ARBITRARY TEXT IN THE FORTRAN CHARACTER SET AND
826: * MAY BE USED IN CONSTRUCTING A FILE OF ERROR
827: * MESSAGES FOR DOCUMENTING PURPOSES OR FOR BUILDING
828: * A DIRECT ACCESS OR OTHER FILE OF MESSAGES TO BE
829: * USED BY THE ERROR HANDLING CODE.
830: * IN THE EVENT THAT AN EXI ATTEMPTS
831: * TO RETURN CONTROL VIA AN EXIT PARAMETER TO
832: * AN ERR, CONTROL IS INSTEAD PASSED TO THE FIRST
833: * INSTRUCTION IN THE ERROR SECTION (WHICH FOLLOWS THE
834: * PROGRAM SECTION) WITH THE ERROR CODE IN WA.
835: *
836: * 1.15 ERB INT,TEXT ERROR BRANCH
837: *
838: * THIS INSTRUCTION RESEMBLES ERR EXCEPT THAT IT MAY
839: * OCCUR AT ANY POINT WHERE A BRANCH IS PERMITTED.
840: * IT EFFECTS A TRANSFER OF CONTROL TO THE ERROR
841: * SECTION WITH THE ERROR CODE IN WA.
842: *
843: * 1.16 ICV OPN INCREMENT VALUE BY ONE
844: *
845: * ICV INCREMENTS THE VALUE OF THE OPERAND BY UNITY.
846: * IT IS EQUIVALENT TO ADD =UNITY,OPN
847: *
848: * 1.17 DCV OPN DECREMENT VALUE BY ONE
849: *
850: * DCV DECREMENTS THE VALUE OF THE OPERAND BY UNITY.
851: * IT IS EQUIVALENT TO SUB =UNITY,OPN
852: EJC
853: *
854: * BASIC INSTRUCTIONS (CONTINUED)
855: *
856: * 1.18 ZER OPN ZEROISE OPN
857: *
858: * ZER IS EQUIVALENT TO MOV =ZEROE,OPN
859: *
860: * 1.19 MNZ OPN MOVE NON-ZERO TO OPN
861: *
862: * ANY NON-ZERO COLLECTABLE VALUE MAY USED, FOR WHICH
863: * THE OPCODES BNZ/BZE WILL BRANCH/FAIL TO BRANCH.
864: *
865: * 1.20 SSL OPW SUBROUTINE STACK LOAD
866: *
867: * 1.21 SSS OPW SUBROUTINE STACK STORE
868: *
869: * THIS PAIR OF OPERATIONS IS PROVIDED TO MAKE POSSIBLE
870: * THE USE OF A LOCAL STACK TO HOLD SUBROUTINE (S-R)
871: * RETURN LINKS FOR N-TYPE PROCEDURES. SSS STORES THE
872: * S-R STACK POINTER IN OPW AND SSL LOADS THE S-R
873: * STACK POINTER FROM OPW. BY USING SSS IN THE MAIN
874: * PROGRAM OR ON ENTRY TO A PROCEDURE WHICH SHOULD
875: * REGAIN CONTROL ON OCCURRENCE OF AN ERR OR ERB AND BY
876: * USE OF SSL IN THE ERROR PROCESSING SECTIONS THE
877: * S-R STACK POINTER CAN BE RESTORED GIVING A LINK
878: * STACK CLEANED UP READY FOR RESUMED EXECUTION.
879: * THE FORM OF THE LINK STACK POINTER IS UNDEFINED IN
880: * MINIMAL (IT IS LIKELY TO BE A PRIVATE REGISTER
881: * KNOWN TO THE TRANSLATOR) AND THE ONLY REQUIREMENT
882: * IS THAT IT SHOULD FIT INTO A SINGLE FULL WORD.
883: * SSL AND SSS ARE NO-OPS IF A PRIVATE LINK STACK IS
884: * NOT USED.
885: *
886: * 1.22 RTN DEFINE START OF ROUTINE
887: *
888: * A ROUTINE IS A CODE CHUNK USED FOR SIMILAR PURPOSES
889: * TO A PROCEDURE. HOWEVER IT IS ENTERED BY ANY TYPE OF
890: * CONDITIONAL OR UNCONDITIONAL BRANCH (NOT BY JSR). ON
891: * TERMINATION IT PASSES CONTROL BY A BRANCH (OFTEN
892: * BRI THROUGH A CODE WORD) OR EVEN PERMITS CONTROL
893: * TO DROP THROUGH TO ANOTHER ROUTINE. NO RETURN LINK
894: * EXISTS AND THE END OF A ROUTINE IS NOT MARKED BY
895: * AN EXPLICIT OPCODE (COMPARE ENP).
896: * ALL ROUTINES SHOULD BE NAMED IN SECTION 0
897: * INR STATEMENTS.
898: EJC
899: *
900: * -2- OPERATIONS ON ONE WORD INTEGER VALUES (ADDRESSES)
901: *
902: * 2.1 ADD OPV,OPN ADDS OPV TO THE VALUE IN OPN AND
903: * STORES THE RESULT IN OPN. UNDEFINED
904: * IF THE RESULT EXCEEDS CFP$M.
905: *
906: * 2.2 SUB OPV,OPN SUBTRACTS OPV FROM OPN. STORES THE
907: * RESULT IN OPN. UNDEFINED IF THE
908: * RESULT IS NEGATIVE.
909: *
910: * 2.3 ICA OPN INCREMENT ADDRESS IN OPN
911: * EQUIVALENT TO ADD *UNITY,OPN
912: *
913: * 2.4 DCA OPN DECREMENT ADDRESS IN OPN
914: * EQUIVALENT TO SUB *UNITY,OPN
915: *
916: * 2.5 BEQ OPN,OPV,PLBL BRANCH TO PLBL IF OPN EQ OPV
917: * 2.6 BNE OPN,OPV,PLBL BRANCH TO PLBL IF OPN NE OPV
918: * 2.7 BGT OPN,OPV,PLBL BRANCH TO PLBL IF OPN GT OPV
919: * 2.8 BGE OPN,OPV,PLBL BRANCH TO PLBL IF OPN GE OPV
920: * 2.9 BLT OPN,OPV,PLBL BRANCH TO PLBL IF OPN LT OPV
921: * 2.10 BLE OPN,OPV,PLBL BRANCH TO PLBL IF OPN LE OPV
922: * 2.11 BLO OPN,OPV,PLBL EQUIVALENT TO BLT OR BLE
923: * 2.12 BHI OPN,OPV,PLBL EQUIVALENT TO BGT OR BGE
924: *
925: * THE ABOVE INSTRUCTIONS COMPARE TWO ADDRESS
926: * VALUES AS UNSIGNED INTEGER VALUES.
927: * THE BLO AND BHI INSTRUCTIONS ARE USED IN CASES WHERE
928: * THE EQUAL CONDITION EITHER DOES NOT OCCUR OR CAN
929: * RESULT EITHER IN A BRANCH OR NO BRANCH. THIS AVOIDS
930: * INEFFICIENT TRANSLATIONS IN SOME IMPLEMENTATIONS.
931: *
932: * 2.13 BNZ OPN,PLBL EQUIVALENT TO BNE OPN,=ZEROE,PLBL
933: *
934: * 2.14 BZE OPN,PLBL EQUIVALENT TO BEQ OPN,=ZEROE,PLBL
935: *
936: *
937: * 2.15 LCT W,OPV LOAD COUNTER FOR BCT
938: *
939: * LCT LOADS A COUNTER VALUE FOR USE WITH THE BCT
940: * INSTRUCTION. THE VALUE IN OPV IS THE NUMBER OF LOOPS
941: * TO BE EXECUTED. THE VALUE IN W AFTER THIS OPERATION
942: * IS AN UNDEFINED ONE WORD INTEGER QUANTITY.
943: *
944: * 2.16 BCT W,PLBL BRANCH AND COUNT
945: *
946: * BCT USES THE COUNTER VALUE IN W TO BRANCH THE
947: * REQUIRED NUMBER OF TIMES AND THEN FINALLY TO FALL
948: * THROUGH TO THE NEXT INSTRUCTION. BCT CAN ONLY BE
949: * USED FOLLOWING AN APPROPRIATE LCT INSTRUCTION.
950: * THE VALUE IN W AFTER EXECUTION OF BCT IS UNDEFINED.
951: *
952: * 2.17 AOV OPV,OPN,PLBL ADD WITH OVERFLOW TEST
953: *
954: * ADDS OPV TO THE VALUE IN OPN AND STORES RESULT IN
955: * OPN. BRANCHES TO PLBL IF RESULT EXCEEDS CFP$M
956: * WITH RESULT IN OPN UNDEFINED. CF. ADD.
957: EJC
958: *
959: * -3- OPERATIONS ON THE CODE POINTER REGISTER (CP)
960: *
961: * THE CODE POINTER REGISTER PROVIDES A PSUEDO
962: * INSTRUCTION COUNTER FOR USE IN AN INTERPRETOR. IT
963: * MAY BE IMPLEMENTED AS A REAL REGISTER OR AS A
964: * MEMORY LOCATION, BUT IN EITHER CASE IT IS SEPARATE
965: * FROM ANY OTHER REGISTER. THE VALUE IN THE CODE
966: * POINTER REGISTER IS ALWAYS A WORD ADDRESS (I.E.
967: * A ONE WORD INTEGER WHICH IS A MULTIPLE OF CFP$B).
968: *
969: * 3.1 LCP REG LOAD CODE POINTER REGISTER
970: * THIS INSTRUCTION CAUSES THE CODE
971: * POINTER REGISTER TO BE SET FROM
972: * THE VALUE IN REG WHICH IS UNCHANGED
973: *
974: * 3.2 SCP REG STORE CODE POINTER REGISTER
975: * THIS INSTRUCTION LOADS THE CURRENT
976: * VALUE IN THE CODE POINTER REGISTER
977: * INTO REG. (CP) IS UNCHANGED.
978: *
979: * 3.3 LCW REG LOAD NEXT CODE WORD
980: * THIS INSTRUCTION CAUSES THE WORD
981: * POINTED TO BY CP TO BE LOADED INTO
982: * THE INDICATED REG. THE VALUE IN CP
983: * IS THEN INCREMENTED BY ONE WORD.
984: * EXECUTION OF LCW MAY DESTROY XL.
985: *
986: * 3.4 ICP INCREMENT CP BY ONE WORD
987: *
988: * ON MACHINES WITH MORE THAN THREE INDEX REGISTERS,
989: * CP CAN BE TREATED SIMPLY AS AN INDEX REGISTER.
990: * IN THIS CASE, THE FOLLOWING EQUIVALENCES APPLY.
991: *
992: * LCP REG IS LIKE MOV REG,CP
993: * SCP REG IS LIKE MOV CP,REG
994: * LCW REG IS LIKE MOV (CP)+,REG
995: * ICP IS LIKE ICA CP
996: *
997: * SINCE LCW IS ALLOWED TO DESTROY XL, THE FOLLOWING
998: * IMPLEMENTATION USING A WORK LOCATION CP$$$ CAN
999: * ALSO BE USED.
1000: *
1001: * LCP REG MOV REG,CP$$$
1002: *
1003: * SCP REG MOV CP$$$,REG
1004: *
1005: * LCW REG MOV CP$$$,XL
1006: * MOV (XL)+,REG
1007: * MOV XL,CP$$$
1008: *
1009: * ICP ICA CP$$$
1010: EJC
1011: *
1012: * -4- OPERATIONS ON SIGNED INTEGER VALUES
1013: *
1014: * 4.1 LDI OPS LOAD INTEGER ACCUMULATOR FROM OPS
1015: * 4.2 ADI OPS ADD OPS TO INTEGER ACCUMULATOR
1016: * 4.3 MLI OPS MULTIPLY INTEGER ACCUMULATOR BY OPS
1017: * 4.4 SBI OPS SUBTRACT OPS FROM INT ACCUMULATOR
1018: * 4.5 DVI OPS DIVIDE INTEGER ACCUMULATOR BY OPS
1019: * 4.6 RMI OPS SET INT ACCUM TO MOD(INTACC,OPS)
1020: * 4.7 STI OPS STORE INTEGER ACCUMULATOR AT OPS
1021: * 4.8 NGI NEGATE THE VALUE IN THE INTEGER
1022: * ACCUMULATOR (CHANGE ITS SIGN)
1023: *
1024: * THE EQUATION SATISFIED BY OPERANDS AND RESULTS OF
1025: * DVI AND RMI IS
1026: * DIV = QOT * OPS + REM WHERE
1027: * DIV = DIVIDEND IN INTEGER ACCUMULATOR
1028: * QOT = QUOTIENT LEFT IN IA BY DIV
1029: * OPS = THE DIVISOR
1030: * REM = REMAINDER LEFT IN IA BY RMI
1031: * THE SIGN OF THE RESULT OF DVI IS + IF (IA) AND (OPS)
1032: * HAVE THE SAME SIGN AND IS - IF THEY HAVE OPPOSITE
1033: * SIGNS. THE SIGN OF (IA) IS ALWAYS USED AS THE SIGN
1034: * OF THE RESULT OF REM.
1035: * ASSUMING IN EACH CASE THAT IA CONTAINS THE NUMBER
1036: * SPECIFIED IN PARENTHESES AND THAT SEVEN AND MSEVN
1037: * HOLD +7 AND -7 RESP. THE ALGORITHM IS ILLUSTRATED
1038: * BELOW.
1039: * (IA = 13)
1040: * DVI SEVEN IA = 1
1041: * RMI SEVEN IA = 6
1042: * DVI MSEVN IA = -1
1043: * RMI MSEVN IA = 6
1044: * (IA = -13)
1045: * DVI SEVEN IA = -1
1046: * RMI SEVEN IA = -6
1047: * DVI MSEVN IA = 1
1048: * RMI MSEVN IA = -6
1049: EJC
1050: *
1051: * THE ABOVE INSTRUCTIONS OPERATE ON A FULL RANGE OF
1052: * SIGNED INTEGER VALUES. WITH THE EXCEPTION OF LDI AND
1053: * STI, THESE INSTRUCTIONS MAY CAUSE INTEGER OVERFLOW
1054: * BY ATTEMPTING TO PRODUCE AN UNDEFINED OR OUT OF
1055: * RANGE RESULT IN WHICH CASE INTEGER OVERFLOW IS SET,
1056: * THE RESULT IN (IA) IS UNDEFINED AND THE FOLLOWING
1057: * INSTRUCTION MUST BE IOV OR INO.
1058: * PARTICULAR CARE MAY BE NEEDED ON TARGET MACHINES
1059: * HAVING DISTINCT OVERFLOW AND DIVIDE BY ZERO
1060: * CONDITIONS.
1061: *
1062: * 4.9 INO PLBL JUMP TO PLBL IF NO INTEGER OVERFLOW
1063: * 4.10 IOV PLBL JUMP TO PLBL IF INTEGER OVERFLOW
1064: *
1065: * THESE INSTRUCTIONS CAN ONLY OCCUR IMMEDIATELY
1066: * FOLLOWING AN INSTRUCTION WHICH CAN CAUSE INTEGER
1067: * OVERFLOW (ADI, SBI, MLI, DVI, RMI, NGI) AND
1068: * TEST THE RESULT OF THE PRECEDING INSTRUCTION.
1069: * IOV AND INO MAY NOT HAVE LABELS.
1070: *
1071: * 4.11 IEQ PLBL JUMP TO PLBL IF (IA) EQ 0
1072: * 4.12 IGE PLBL JUMP TO PLBL IF (IA) GE 0
1073: * 4.13 IGT PLBL JUMP TO PLBL IF (IA) GT 0
1074: * 4.14 ILE PLBL JUMP TO PLBL IF (IA) LE 0
1075: * 4.15 ILT PLBL JUMP TO PLBL IF (IA) LT 0
1076: * 4.16 INE PLBL JUMP TO PLBL IF (IA) NE 0
1077: *
1078: * THE ABOVE CONDITIONAL JUMP INSTRUCTIONS DO
1079: * NOT CHANGE THE CONTENTS OF THE ACCUMULATOR.
1080: * ON A ONES COMPLEMENT MACHINE, IT IS PERMISSIBLE TO
1081: * PRODUCE NEGATIVE ZERO IN IA PROVIDED THESE
1082: * INSTRUCTIONS OPERATE CORRECTLY WITH SUCH A VALUE.
1083: EJC
1084: *
1085: * -5- OPERATIONS ON REAL VALUES
1086: *
1087: * 5.1 LDR OPS LOAD REAL ACCUMULATOR FROM OPS
1088: * 5.2 STR OPS STORE REAL ACCUMULATOR AT OPS
1089: * 5.3 ADR OPS ADD OPS TO REAL ACCUMULATOR
1090: * 5.4 SBR OPS SUBTRACT OPS FROM REAL ACCUMULATOR
1091: * 5.5 MLR OPS MULTIPLY REAL ACCUMULATOR BY OPS
1092: * 5.6 DVR OPS DIVIDE REAL ACCUMULATOR BY OPS
1093: *
1094: * IF THE RESULT OF ANY OF THE ABOVE OPERATIONS CAUSES
1095: * UNDERFLOW, THE RESULT YIELDED IS 0.0.
1096: *
1097: * IF THE RESULT OF ANY OF THE ABOVE OPERATIONS IS
1098: * UNDEFINED OR OUT OF RANGE, REAL OVERFLOW IS SET,
1099: * THE CONTENTS OF (RA) ARE UNDEFINED AND THE FOLLOWING
1100: * INSTRUCTION MUST BE EITHER ROV OR RNO.
1101: * PARTICULAR CARE MAY BE NEEDED ON TARGET MACHINES
1102: * HAVING DISTINCT OVERFLOW AND DIVIDE BY ZERO
1103: * CONDITIONS.
1104: *
1105: * 5.7 ROV PLBL JUMP TO PLBL IF REAL OVERFLOW
1106: * 5.8 RNO PLBL JUMP TO PLBL IF NO REAL OVERFLOW
1107: *
1108: * THESE INSTRUCTIONS CAN ONLY OCCUR IMMEDIATELY
1109: * FOLLOWING AN INSTRUCTION WHICH CAN CAUSE REAL
1110: * OVERFLOW (ADR,SBR,MLR,DVR).
1111: *
1112: * 5.9 NGR NEGATE REAL ACCUM (CHANGE SIGN)
1113: *
1114: * 5.10 REQ PLBL JUMP TO PLBL IF (RA) EQ 0.0
1115: * 5.11 RGE PLBL JUMP TO PLBL IF (RA) GE 0.0
1116: * 5.12 RGT PLBL JUMP TO PLBL IF (RA) GT 0.0
1117: * 5.13 RLE PLBL JUMP TO PLBL IF (RA) LE 0.0
1118: * 5.14 RLT PLBL JUMP TO PLBL IF (RA) LT 0.0
1119: * 5.15 RNE PLBL JUMP TO PLBL IF (RA) NE 0.0
1120: *
1121: * THE ABOVE CONDITIONAL INSTRUCTIONS DO NOT AFFECT
1122: * THE VALUE STORED IN THE REAL ACCUMULATOR.
1123: * ON A ONES COMPLEMENT MACHINE, IT IS PERMISSIBLE TO
1124: * PRODUCE NEGATIVE ZERO IN RA PROVIDED THESE
1125: * INSTRUCTIONS OPERATE CORRECTLY WITH SUCH A VALUE.
1126: EJC
1127: *
1128: * -6- OPERATIONS ON CHARACTER VALUES
1129: *
1130: * CHARACTER OPERATIONS EMPLOY THE CONCEPT OF A
1131: * CHARACTER POINTER WHICH USES EITHER
1132: * INDEX REGISTER XR OR XL (NOT XS).
1133: *
1134: * A CHARACTER POINTER POINTS TO A SPECIFIC CHARACTER
1135: * IN A STRING OF CHARACTERS STORED CFP$C CHARS TO A
1136: * WORD. THE ONLY OPERATIONS PERMITTED ON A CHARACTER
1137: * POINTER ARE LCH AND SCH. IN PARTICULAR, A CHARACTER
1138: * POINTER MAY NOT EVEN BE MOVED WITH MOV.
1139: *
1140: * RESTRICTION 1.
1141: * --------------
1142: * IT IS IMPORTANT WHEN CODING IN MINIMAL TO ENSURE
1143: * THAT NO ACTION OCCURRING BETWEEN THE INITIAL USE OF
1144: * PLC OR PSC AND THE EVENTUAL CLEARING OF XL OR XR ON
1145: * COMPLETION OF CHARACTER OPERATIONS CAN INITIATE A
1146: * GARBAGE COLLECTION. THE LATTER OF COURSE COULD CAUSE
1147: * THE ADDRESSED CHARACTERS TO BE MOVED LEAVING THE
1148: * CHARACTER POINTERS POINTING TO RUBBISH.
1149: *
1150: * RESTRICTION 2.
1151: * --------------
1152: * A FURTHER RESTRICTION TO BE OBSERVED IN CODE
1153: * HANDLING CHARACTER STRINGS, IS THAT STRINGS BUILT
1154: * DYNAMICALLY SHOULD BE RIGHT PADDED WITH ZERO
1155: * CHARACTERS TO A FULL WORD BOUNDARY TO PERMIT EASY
1156: * HASHING AND USE OF CEQ OR CNE IN TESTING STRINGS
1157: * FOR EQUALITY.
1158: *
1159: * 6.1 PLC X,OPV PREPARE CH PTR FOR LCH,CMC,MVC,TRC
1160: *
1161: * 6.2 PSC X,OPV PREPARE CHAR. PTR FOR SCH,MVC.
1162: *
1163: * OPV CAN BE OMITTED IF IT IS ZERO.
1164: * THE CHAR. INITIALLY ADDRESSED IS DETERMINED BY THE
1165: * WORD ADDRESS IN X AND THE INTEGER OFFSET OPV.
1166: * THERE IS AN AUTOMATIC IMPLIED OFFSET OF CFP$F BYTES.
1167: * CFP$F IS USED TO FORMALLY INTRODUCE INTO MINIMAL A
1168: * VALUE NEEDED IN TRANSLATING THESE OPCODES WHICH,
1169: * SINCE MINIMAL ITSELF DOES NOT PRESCRIBE A STRING
1170: * STRUCTURE IN DETAIL, DEPENDS ON THE CHOICE OF A DATA
1171: * STRUCTURE FOR STRINGS IN THE MINIMAL PROGRAM.
1172: * E.G. IF CFP$B = CFP$C = 3, CFP$F = 6, NUM01 = 1, XL
1173: * POINTS TO A SERIES OF 4 WORDS, ABC/DEF/GHI/JKL, THEN
1174: * PLC XL,=NUM01
1175: * POINTS TO H.
1176: EJC
1177: *
1178: * -6- OPERATIONS ON CHARACTER VALUES (CONTINUED)
1179: *
1180: * 6.3 LCH REG,OPC LOAD CHARACTER INTO REG
1181: *
1182: * 6.4 SCH REG,OPC STORE CHARACTER FROM REG
1183: *
1184: * THESE OPERATIONS ARE DEFINED SUCH THAT THE CHARACTER
1185: * IS RIGHT JUSTIFIED IN REGISTER REG WITH ZERO BITS TO
1186: * THE LEFT. AFTER LCH FOR EXAMPLE, IT IS LEGITIMATE
1187: * TO REGARD REG AS CONTAINING THE ORDINAL INTEGER
1188: * CORRESPONDING TO THE CHARACTER.
1189: *
1190: * OPC IS ONE OF THE FOLLOWING THREE POSSIBILITIES.
1191: *
1192: * (X) THE CHARACTER POINTED TO BY THE
1193: * CHARACTER POINTER IN X. THE
1194: * CHARACTER POINTER IS NOT CHANGED.
1195: *
1196: * (X)+ SAME CHARACTER AS (X) BUT THE
1197: * CHARACTER POINTER IS INCREMENTED
1198: * TO POINT TO THE NEXT CHARACTER
1199: * FOLLOWING EXECUTION.
1200: *
1201: * -(X) THE CHARACTER POINTER IS DECRE-
1202: * MENTED BEFORE ACCESSING THE
1203: * CHARACTER SO THAT THE PREVIOUS
1204: * CHARACTER IS REFERENCED.
1205: *
1206: * 6.5 CSC X COMPLETE STORE CHARACTERS
1207: *
1208: * THIS INSTRUCTION MARKS COMPLETION OF A
1209: * PSC,SCH,SCH,...,SCH SEQUENCE INITIATED BY
1210: * A PSC X INSTRUCTION. NO MORE SCH INSTRUCTIONS
1211: * USING X SHOULD BE OBEYED UNTIL ANOTHER PSC
1212: * IS OBEYED. THIS MAKES BUFFERING OF SCH CHARS
1213: * FEASIBLE ON MACHINES LACKING CHARACTER ORDERS.
1214: * IF CSC IS NOT A NO-OP, IT MUST OBSERVE RESTRICTION 2
1215: *
1216: * THE FOLLOWING INSTRUCTIONS ARE USED TO COMPARE
1217: * TWO WORDS CONTAINING CFP$C CHARACTERS.
1218: * COMPARISONS DISTINCT FROM BEQ,BNE ARE PROVIDED AS
1219: * ON SOME TARGET MACHINES, THE POSSIBILITY OF THE SIGN
1220: * BIT BEING SET MAY REQUIRE SPECIAL ACTION.
1221: * NOTE THAT RESTRICTION 2 ABOVE, EASES USE OF THESE
1222: * ORDERS IN TESTING COMPLETE STRINGS FOR EQUALITY,
1223: * SINCE WHOLE WORD TESTS ARE POSSIBLE.
1224: *
1225: * 6.6 CEQ OPW,OPW,PLBL JUMP TO PLBL IF OPW EQ OPW
1226: * 6.7 CNE OPW,OPW,PLBL JUMP TO PLBL IF OPW NE OPW
1227: EJC
1228: *
1229: * -6- OPERATIONS ON CHARACTER VALUES (CONTINUED)
1230: *
1231: * 6.8 CMC PLBL,PLBL COMPARE CHARACTERS
1232: *
1233: * CMC IS USED TO COMPARE TWO CHARACTER STRINGS. BEFORE
1234: * EXECUTING CMC, REGISTERS ARE SET UP AS FOLLOWS.
1235: * (XL) CHARACTER PTR FOR FIRST STRING
1236: * (XR) CHARACTER POINTER FOR SECOND STRING
1237: * (WA) CHARACTER COUNT (MUST BE .GT. ZERO)
1238: * XL AND XR SHOULD HAVE BEEN PREPARED BY PLC.
1239: * CONTROL PASSES TO FIRST PLBL IF THE FIRST STRING
1240: * IS LEXICALLY LESS THAN THE SECOND STRING, AND TO
1241: * THE SECOND PLBL IF THE FIRST STRING IS LEXICALLY
1242: * GREATER. CONTROL PASSES TO THE FOLLOWING INSTRUCTION
1243: * IF THE STRINGS ARE IDENTICAL. AFTER EXECUTING THIS
1244: * INSTRUCTION, THE VALUES OF XR AND XL ARE SET TO ZERO
1245: * AND THE VALUE IN (WA) IS UNDEFINED.
1246: * ARGUMENTS TO CMC MAY BE COMPLETE OR PARTIAL
1247: * STRINGS, SO MAKING OPTIMISATION TO USE WHOLE WORD
1248: * COMPARISONS DIFFICULT (DEPENDENT IN GENERAL ON
1249: * SHIFTS AND MASKING).
1250: *
1251: * 6.9 TRC TRANSLATE CHARACTERS
1252: *
1253: * TRC IS USED TO TRANSLATE A CHARACTER STRING USING A
1254: * SUPPLIED TRANSLATION TABLE. BEFORE EXECUTING TRC THE
1255: * REGISTERS ARE SET AS FOLLOWS.
1256: * (XL) CHAR PTR TO STRING TO BE TRANSLATED
1257: * (XR) CHAR PTR TO TRANSLATE TABLE
1258: * (WA) LENGTH OF STRING TO BE TRANSLATED
1259: * XL AND XR SHOULD HAVE BEEN PREPARED BY PLC.
1260: * THE TRANSLATE TABLE CONSISTS OF CFP$A CONTIGUOUS
1261: * CHARACTERS GIVING THE TRANSLATIONS OF THE CFP$A
1262: * CHARACTERS IN THE ALPHABET. ON COMPLETION, (XR) AND
1263: * (XL) ARE SET TO ZERO AND (WA) IS UNDEFINED.
1264: EJC
1265: *
1266: * -7- OPERATIONS ON BIT STRING VALUES
1267: *
1268: * 7.1 ANB OPW,W AND BIT STRING VALUES
1269: * 7.2 ORB OPW,W OR BIT STRING VALUES
1270: * 7.3 XOB OPW,W EXCLUSIVE OR BIT STRING VALUES
1271: *
1272: * IN THE ABOVE OPERATIONS, THE LOGICAL CONNECTIVE IS
1273: * APPLIED SEPARATELY TO EACH OF THE CFP$N BITS.
1274: * THE RESULT IS STORED IN THE SECOND OPERAND LOCATION.
1275: *
1276: * 7.4 CMB W COMPLEMENT ALL BITS IN OPW
1277: *
1278: * 7.5 RSH W,VAL RIGHT SHIFT BY VAL BITS
1279: * 7.6 LSH W,VAL LEFT SHIFT BY VAL BITS
1280: * 7.7 RSX W,(X) RIGHT SHIFT W NUMBER OF BITS IN X
1281: * 7.8 LSX W,(X) LEFT SHIFT W NUMBER OF BITS IN X
1282: *
1283: * THE ABOVE SHIFTS ARE LOGICAL SHIFTS IN WHICH BITS
1284: * SHIFTED OUT ARE LOST AND ZERO BITS SUPPLIED AS
1285: * REQUIRED. THE SHIFT COUNT IS IN THE RANGE 0-CFP$N.
1286: *
1287: * 7.9 NZB W,PLBL JUMP TO PLBL IF W IS NOT
1288: * ALL ZERO BITS.
1289: *
1290: * 7.10 ZRB W,PLBL JUMP TO PLBL IF W IS ALL ZERO BITS
1291: *
1292: * 7.11 ZGB OPN ZEROISE GARBAGE BITS
1293: *
1294: * OPN CONTAINS A BIT STRING REPRESENTING A WORD
1295: * OF CHARACTERS FROM A STRING OR SOME FUNCTION
1296: * FORMED FROM SUCH CHARACTERS (E.G. AS A RESULT OF
1297: * HASHING). ON A MACHINE WHERE THE WORD SIZE IS NOT A
1298: * MULTIPLE OF THE CHARACTER SIZE, SOME BITS IN REG MAY
1299: * BE UNDEFINED. THIS OPCODE REPLACES SUCH BITS BY THE
1300: * ZERO BIT. ZGB IS A NO-OP IF THE WORD SIZE IS A
1301: * MULTIPLE OF THE CHARACTER SIZE.
1302: EJC
1303: *
1304: * -8- CONVERSION INSTRUCTIONS
1305: *
1306: * THE FOLLOWING INSTRUCTIONS PROVIDE FOR CONVERSION
1307: * BETWEEN LENGTHS IN BYTES AND LENGTHS IN WORDS.
1308: *
1309: * 8.1 WTB REG CONVERT REG FROM WORDS TO BYTES.
1310: * THAT IS, MULTIPLY BY CFP$B. THIS IS
1311: * A NO-OP IF CFP$B IS ONE.
1312: *
1313: * 8.2 BTW REG CONVERT REG FROM BYTES TO WORDS
1314: * BY DIVIDING REG BY CFP$B DISCARDING
1315: * THE FRACTION. NO-OP IF CFP$B IS ONE
1316: *
1317: * THE FOLLOWING INSTRUCTIONS PROVIDE FOR CONVERSION
1318: * OF ONE WORD INTEGER VALUES (ADDRESSES) TO AND
1319: * FROM THE FULL SIGNED INTEGER FORMAT.
1320: *
1321: * 8.3 MTI OPN THE VALUE OF OPN (AN ADDRESS)
1322: * IS MOVED AS A POSITIVE INTEGER
1323: * TO THE INTEGER ACCUMULATOR.
1324: *
1325: * 8.4 MFI OPN,PLBL THE VALUE CURRENTLY STORED IN THE
1326: * INTEGER ACCUMULATOR IS MOVED
1327: * TO OPN AS AN ADDRESS IF IT IS IN
1328: * THE RANGE 0 TO CFP$M INCLUSIVE.
1329: * IF THE ACCUMULATOR VALUE IS
1330: * OUTSIDE THIS RANGE, THEN THE RESULT
1331: * IN OPN IS UNDEFINED AND CONTROL IS
1332: * PASSED TO PLBL. MFI DESTROYS THE
1333: * VALUE OF (IA) WHETHER OR NOT
1334: * INTEGER OVERFLOW IS SIGNALLED.
1335: * PLBL MAY BE OMITTED IF OVERFLOW
1336: * IS IMPOSSIBLE.
1337: *
1338: * THE FOLLOWING INSTRUCTIONS PROVIDE FOR CONVERSION
1339: * BETWEEN REAL VALUES AND INTEGER VALUES.
1340: *
1341: * 8.5 ITR CONVERT INTEGER VALUE IN INTEGER
1342: * ACCUMULATOR TO REAL AND STORE IN
1343: * REAL ACCUMULATOR (MAY LOSE
1344: * PRECISION IN SOME CASES)
1345: *
1346: * 8.6 RTI PLBL CONVERT THE REAL VALUE IN RA TO
1347: * AN INTEGER AND PLACE RESULT IN IA.
1348: * CONVERSION IS BY TRUNCATION OF THE
1349: * FRACTION - NO ROUNDING OCCURS.
1350: * JUMP TO PLBL IF OUT OF RANGE. (RA)
1351: * IS NOT CHANGED IN EITHER CASE.
1352: * PLBL MAY BE OMITTED IF OVERFLOW
1353: * IS IMPOSSIBLE.
1354: EJC
1355: *
1356: * -8- CONVERSION INSTRUCTIONS (CONTINUED)
1357: *
1358: * THE FOLLOWING INSTRUCTIONS PROVIDE FOR COMPUTING
1359: * THE LENGTH OF STORAGE REQUIRED FOR A TEXT STRING.
1360: *
1361: * 8.7 CTW W,VAL THIS INSTRUCTION COMPUTES THE SUM
1362: * (NUMBER OF WORDS REQUIRED TO STORE
1363: * W CHARACTERS) + (VAL). THE SUM
1364: * IS STORED IN W.
1365: * FOR EXAMPLE, IF CFP$C IS 5, AND WA
1366: * CONTAINS 32, THEN CTW WA,2
1367: * GIVES A RESULT OF 9 IN WA.
1368: *
1369: * 8.8 CTB W,VAL CTB IS EXACTLY LIKE CTW EXCEPT THAT
1370: * THE RESULT IS IN BYTES. IT HAS THE
1371: * SAME EFFECT AS CTW W,VAL WTB W
1372: *
1373: * THE FOLLOWING INSTRUCTIONS PROVIDE FOR CONVERSION
1374: * FROM INTEGERS TO AND FROM NUMERIC DIGIT CHARACTERS
1375: * FOR USE IN NUMERIC CONVERSION ROUTINES. THEY EMPLOY
1376: * NEGATIVE INTEGER VALUES TO ALLOW FOR PROPER
1377: * CONVERSION OF NUMBERS WHICH CANNOT BE COMPLEMENTED.
1378: *
1379: * 8.9 CVM PLBL CONVERT BY MULTIPLICATION
1380: *
1381: * THE INTEGER ACCUMULATOR, WHICH IS ZERO OR NEGATIVE,
1382: * IS MULTIPLIED BY 10. WB CONTAINS THE CHARACTER
1383: * CODE FOR A DIGIT. THE VALUE OF THIS DIGIT IS THEN
1384: * SUBTRACTED FROM THE RESULT. IF THE RESULT IS OUT OF
1385: * RANGE, THEN CONTROL IS PASSED TO PLBL WITH THE
1386: * RESULT IN (IA) UNDEFINED. EXECUTION OF CVM LEAVES
1387: * THE RESULT IN (WB) UNDEFINED.
1388: *
1389: * 8.10 CVD CONVERT BY DIVISION
1390: *
1391: * THE INTEGER ACCUMULATOR, WHICH IS ZERO OR NEGATIVE,
1392: * IS DIVIDED BY 10. THE QUOTIENT (ZERO OR NEGATIVE)
1393: * IS REPLACED IN THE ACCUMULATOR. THE REMAINDER IS
1394: * CONVERTED TO THE CHARACTER CODE OF A DIGIT AND
1395: * PLACED IN WA. FOR EXAMPLE, AN OPERAND OF -523 GIVES
1396: * A QUOTIENT OF -52 AND A REMAINDER IN WA OF CH$D3.
1397: EJC
1398: *
1399: * -9- BLOCK MOVE INSTRUCTIONS
1400: *
1401: * THE FOLLOWING INSTRUCTIONS ARE USED FOR TRANSFERRING
1402: * DATA FROM ONE AREA OF MEMORY TO ANOTHER IN BLOCKS.
1403: * THEY CAN BE IMPLEMENTED WITH THE INDICATED SERIES OF
1404: * OTHER MACRO-INSTRUCTIONS, BUT MORE EFFICIENT IMPLE-
1405: * MENTATIONS WILL BE POSSSIBLE ON MOST MACHINES.
1406: *
1407: * 9.1 MVC MOVE CHARACTERS
1408: *
1409: * BEFORE OBEYING THIS ORDER WA,XL,XR SHOLD HAVE BEEN
1410: * SET UP, THE LATTER TWO BY PLC, PSC RESP.
1411: * MVC IS EQUIVALENT TO THE SEQUENCE
1412: *
1413: * MOV WB,DUMPB
1414: * LCT WA,WA
1415: * LOOPC LCH WB,(XL)+
1416: * SCH WB,(XR)+
1417: * BCT WA,LOOPC
1418: * CSC XR
1419: * MOV DUMPB,WB
1420: *
1421: * THE CHARACTER POINTERS ARE BUMPED AS INDICATED
1422: * AND THE FINAL VALUE OF WA IS UNDEFINED.
1423: *
1424: * 9.2 MVW MOVE WORDS
1425: *
1426: * MVW IS EQUIVALENT TO THE SEQUENCE
1427: *
1428: * LOOPW MOV (XL)+,(XR)+
1429: * DCA WA WA = BYTES TO MOVE
1430: * BNZ WA,LOOPW
1431: *
1432: * NOTE THAT THIS IMPLIES THAT THE VALUE IN WA IS THE
1433: * LENGTH IN BYTES WHICH IS A MULTIPLE OF CFP$B.
1434: * THE INITIAL ADDRESSES IN XR,XL ARE WORD ADDRESSES.
1435: * AS INDICATED, THE FINAL XR,XL VALUES POINT PAST THE
1436: * NEW AND OLD REGIONS OF MEMORY RESPECTIVELY.
1437: * THE FINAL VALUE OF WA IS UNDEFINED.
1438: * WA,XL,XR MUST BE SET UP BEFORE OBEYING MVW.
1439: *
1440: * 9.3 MWB MOVE WORDS BACKWARDS
1441: *
1442: * MWB IS EQUIVALENT TO THE SEQUENCE
1443: *
1444: * LOOPB MOV -(XL),-(XR)
1445: * DCA WA WA = BYTES TO MOVE
1446: * BNZ WA,LOOPB
1447: *
1448: * THERE IS A REQUIREMENT THAT THE INITIAL VALUE IN XL
1449: * BE AT LEAST 256 LESS THAN THE VALUE IN XR. THIS
1450: * ALLOWS AN IMPLEMENTATION IN WHICH CHUNKS OF 256
1451: * BYTES ARE MOVED FORWARD (IBM 360, ICL 1900).
1452: * THE FINAL VALUE OF WA IS UNDEFINED.
1453: * WA,XL,XR MUST BE SET UP BEFORE OBEYING MWB.
1454: EJC
1455: *
1456: * -10- OPERATIONS CONNECTED WITH THE STACK
1457: *
1458: * THE STACK IS AN AREA IN MEMORY WHICH IS DEDICATED FOR USE
1459: * IN CONJUNCTION WITH THE STACK POINTER REGISTER (XS). AS
1460: * PREVIOUSLY DESCRIBED, IT IS USED BY THE JSR AND EXI
1461: * INSTRUCTIONS AND MAY BE USED FOR STORAGE OF ANY OTHER
1462: * DATA AS REQUIRED.
1463: *
1464: * THE STACK BUILDS EITHER WAY IN MEMORY AND AN IMPORTANT
1465: * RESTRICTION IS THAT THE VALUE IN (XS) MUST BE THE ADDRESS
1466: * OF THE STACK FRONT AT ALL TIMES SINCE
1467: * SOME IMPLEMENTATIONS MAY RANDOMLY DESTROY STACK LOCATIONS
1468: * BEYOND (XS).
1469: *
1470: * THE STARTING STACK BASE ADDRESS IS PASSED
1471: * IN (XS) AT THE START OF EXECUTION. DURING EXECUTION IT
1472: * IS NECESSARY TO MAKE SURE THAT THE STACK DOES NOT
1473: * OVERFLOW. THIS IS ACHIEVED BY EXECUTING THE FOLLOWING
1474: * INSTRUCTION PERIODICALLY.
1475: *
1476: * 10.1 CHK CHECK STACK OVERFLOW
1477: *
1478: * AFTER SUCCESSFULLY EXECUTING CHK, IT IS PERMISSIBLE TO
1479: * USE UP TO 100 ADDITIONAL WORDS BEFORE ISSUING ANOTHER CHK
1480: * THUS CHK NEED NOT BE ISSUED EVERY TIME THE STACK IS
1481: * EXPANDED. IN SOME IMPLEMENTATIONS, THE CHECKING MAY BE
1482: * AUTOMATIC AND CHK WILL HAVE NO EFFECT. FOLLOWING THE
1483: * ABOVE RULE MAKES SURE THAT THE PROGRAM WILL OPERATE
1484: * CORRECTLY IN IMPLEMENTATIONS WITH NO AUTOMATIC CHECK.
1485: *
1486: * IF STACK OVERFLOW OCCURS (DETECTED EITHER AUTOMATICALLY
1487: * OR BY A CHK INSTRUCTION), THEN CONTROL IS PASSED TO THE
1488: * STACK OVERFLOW SECTION (SEE PROGRAM FORM). NOTE THAT THIS
1489: * TRANSFER MAY TAKE PLACE FOLLOWING ANY INSTRUCTION WHICH
1490: * STORES DATA AT A NEW LOCATION ON THE STACK.
1491: * AFTER STACK OVERFLOW, STACK IS ARBITRARILY POPPED
1492: * TO GIVE SOME SPACE IN WHICH THE ERROR PROCEDURE MAY
1493: * OPERATE. OTHERWISE A LOOP OF STACK OVERFLOWS MAY OCCUR.
1494: EJC
1495: *
1496: * -11- DATA GENERATION INSTRUCTIONS
1497: *
1498: * THE FOLLOWING INSTRUCTIONS ARE USED TO GENERATE CONSTANT
1499: * VALUES IN THE CONSTANT SECTION AND ALSO TO ASSEMBLE
1500: * INITIAL VALUES IN THE WORKING STORAGE SECTION. THEY
1501: * MAY NOT APPEAR EXCEPT IN THESE TWO SECTIONS.
1502: *
1503: * 11.1 DAC ADDR ASSEMBLE ADDRESS CONSTANT.
1504: * GENERATES ONE WORD CONTAINING THE
1505: * SPECIFIED ONE WORD INTEGER
1506: * VALUE (ADDRESS).
1507: *
1508: * 11.2 DIC INTEGER GENERATES AN INTEGER VALUE WHICH
1509: * OCCUPIES CFP$I CONSECUTIVE WORDS.
1510: * THE OPERAND IS A DIGIT STRING WITH
1511: * A REQUIRED LEADING SIGN.
1512: *
1513: * 11.3 DRC REAL ASSEMBLES A REAL CONSTANT WHICH
1514: * OCCUPIES CFP$R CONSECUTIVE WORDS.
1515: * THE OPERAND FORM MUST OBEY THE
1516: * RULES FOR A FORTRAN REAL CONSTANT
1517: * WITH THE EXTRA REQUIREMENT THAT A
1518: * LEADING SIGN BE PRESENT.
1519: *
1520: * 11.4 DTC DTEXT DEFINE TEXT CONSTANT. DTEXT
1521: * IS STARTED AND ENDED WITH ANY
1522: * CHARACTER NOT CONTAINED IN THE
1523: * CHARACTERS TO BE ASSEMBLED. THE
1524: * CONSTANT OCCUPIES CONSECUTIVE WORDS
1525: * AS DICTATED BY THE CONFIGURATION
1526: * PARAMETER CFP$C. ANY UNUSED CHARS
1527: * IN THE LAST WORD ARE RIGHT FILLED
1528: * WITH ZEROS (I.E. THE CHARACTER
1529: * WHOSE INTERNAL CODE IS ZERO).
1530: * THE STRING CONTAINS A SEQUENCE OF
1531: * LETTERS, DIGITS, BLANKS AND ANY OF
1532: * THE FOLLOWING SPECIAL CHARACTERS.
1533: * =,$.(*)/+-
1534: * NO OTHER CHARACTERS
1535: * MAY BE USED IN A DTEXT OPERAND.
1536: *
1537: * 11.5 DBC VAL ASSEMBLE BIT STRING CONSTANT. THE
1538: * OPERAND IS A POSITIVE INTEGER
1539: * VALUE WHICH IS INTERPRETED IN
1540: * BINARY, RIGHT JUSTIFIED AND LEFT
1541: * FILLED WITH ZERO BITS. THUS 5 WOULD
1542: * IMPLY THE BIT STRING VALUE 00..101.
1543: EJC
1544: *
1545: * -12- SYMBOL DEFINITION INSTRUCTIONS
1546: *
1547: * THE FOLLOWING INSTRUCTION IS USED TO DEFINE SYMBOLS
1548: * IN THE DEFINITIONS SECTION. IT MAY NOT BE USED ELSEWHERE.
1549: *
1550: * 12.1 EQU EQOP DEFINE SYMBOL
1551: *
1552: * THE SYMBOL WHICH APPEARS IN THE LABEL FIELD IS
1553: * DEFINED TO HAVE THE ABSOLUTE VALUE GIVEN
1554: * BY THE EQOP OPERAND. A GIVEN SYMBOL MAY BE DEFINED
1555: * ONLY ONCE IN THIS MANNER, AND ANY SYMBOLS OCCURING
1556: * IN EQOP MUST BE PREVIOUSLY DEFINED.
1557: *
1558: * THE FOLLOWING ARE THE POSSIBILITIES FOR EQOP
1559: *
1560: * VAL THE INDICATED VALUE IS USED
1561: *
1562: * VAL+VAL THE SUM OF THE TWO VALUES IS USED.
1563: * THIS SUM MUST NOT EXCEED CFP$M
1564: *
1565: * VAL-VAL THE DIFFERENCE BETWEEN THE TWO
1566: * VALUES (MUST BE POSITIVE) IS USED.
1567: *
1568: * * THIS FORMAT DEFINES THE LABEL BY
1569: * USING A VALUE SUPPLIED BY THE
1570: * MINIMAL TRANSLATOR. VALUES ARE
1571: * REQUIRED FOR THE
1572: * CFP$X (CONFIGURATION PARAMETERS)
1573: * E$XXX (ENVIRONMENT PARAMETERS)
1574: * CH$XX (CHARACTER CODES).
1575: * IN ORDER FOR A TRANSLATOR TO
1576: * HANDLE THIS FORMAT CORRECTLY THE
1577: * DEFINITIONS SECTION MUST BE
1578: * CONSULTED FOR DETAILS OF REQUIRED
1579: * SYMBOLS AS LISTED AT THE FRONT OF
1580: * THE SECTION.
1581: EJC
1582: *
1583: * SYMBOL DEFINITION INSTRUCTIONS (CONTINUED)
1584: *
1585: * THE FOLLOWING INSTRUCTIONS MAY BE USED TO DEFINE SYMBOLS
1586: * IN THE PROCEDURE SECTION. THEY MAY NOT BE USED IN
1587: * ANY OTHER PART OF THE PROGRAM.
1588: *
1589: * 12.2 EXP DEFINE EXTERNAL PROCEDURE
1590: *
1591: * EXP DEFINES THE SYMBOL APPEARING IN THE LABEL FIELD
1592: * TO BE THE NAME OF AN EXTERNAL PROCEDURE WHICH CAN BE
1593: * REFERENCED IN A SUBSEQUENT JSR INSTRUCTION. THE
1594: * CODING FOR THE PROCEDURE IS EXTERNAL TO THE
1595: * CODING OF THE SOURCE PROGRAM IN THIS LANGUAGE.
1596: * THE CODE FOR EXTERNAL PROCEDURES MAY BE
1597: * REFERRED TO COLLECTIVELY AS THE OPERATING SYSTEM
1598: * INTERFACE, OR MORE BRIEFLY, OSINT, AND WILL
1599: * FREQUENTLY BE A SEPARATELY COMPILED SEGMENT OF CODE
1600: * LOADED WITH SPITBOL TO PRODUCE A COMPLETE SYSTEM.
1601: *
1602: * 12.3 INP PTYP,INT DEFINE INTERNAL PROCEDURE
1603: *
1604: * INP DEFINES THE SYMBOL APPEARING IN THE LABEL FIELD
1605: * TO BE THE NAME OF AN INTERNAL PROCEDURE AND GIVES
1606: * ITS TYPE AND NUMBER OF EXIT PARAMETERS. THE LABEL
1607: * CAN BE REFERENCED IN JSR INSTRUCTIONS AND
1608: * IT MUST APPEAR LABELLING A PRC INSTRUCTION IN THE
1609: * PROGRAM SECTION.
1610: *
1611: * 12.4 INR DEFINE INTERNAL ROUTINE
1612: *
1613: * INR DEFINES THE SYMBOL APPEARING IN THE LABEL
1614: * FIELD TO BE THE NAME OF AN INTERNAL ROUTINE. THE
1615: * LABEL MAY BE REFERENCED IN ANY TYPE OF BRANCH ORDER
1616: * AND IT MUST APPEAR LABELLING A RTN INSTRUCTION IN
1617: * THE PROGRAM SECTION.
1618: EJC
1619: *
1620: * -13- ASSEMBLY LISTING LAYOUT INSTRUCTIONS
1621: *
1622: * 13.1 EJC EJECT TO NEXT PAGE
1623: *
1624: * 13.2 TTL TEXT SET NEW ASSEMBLY TITLE
1625: *
1626: * TTL IMPLIES AN IMMEDIATE EJECT OF THE
1627: * ASSEMBLY LISTING TO PRINT THE NEW TITLE.
1628: *
1629: * THE USE OF TTL AND EJC CARDS IS SUCH THAT THE
1630: * PROGRAM WILL LIST NEATLY IF THE PRINTER PRINTS
1631: * AS MANY AS 58 LINES PER PAGE. IN THE EVENT THAT
1632: * THE PRINTER DEPTH IS LESS THAN THIS, OR IF THE
1633: * LISTING CONTAINS INTERSPERSED LINES (SUCH AS ACTUAL
1634: * GENERATED CODE), THEN THE FORMAT MAY BE UPSET.
1635: *
1636: * LINES STARTING WITH AN ASTERISK ARE COMMENT LINES
1637: * WHICH CAUSE NO CODE TO BE GENERATED AND MAY OCCUR
1638: * FREELY ANYWHERE IN THE PROGRAM. THE FORMAT FOR
1639: * COMMENT LINES IS GIVEN IN SECTION -15-.
1640: EJC
1641: *
1642: * -14- PROGRAM FORM
1643: *
1644: * THE PROGRAM CONSISTS OF SEPARATE SECTIONS SEPARATED
1645: * BY SEC OPERATIONS. THE SECTIONS MUST APPEAR IN THE
1646: * FOLLOWING SPECIFIED ORDER.
1647: *
1648: * 14.1 SEC START OF PROCEDURE SECTION
1649: *
1650: * (PROCEDURE SECTION)
1651: *
1652: * SEC START OF DEFINITIONS SECTION
1653: *
1654: * (DEFINITIONS SECTION)
1655: *
1656: * SEC START OF CONSTANT STORAGE SECTION
1657: *
1658: * (CONSTANT STORAGE SECTION)
1659: *
1660: * SEC START OF WORKING STORAGE SECTION
1661: *
1662: * (WORKING STORAGE SECTION)
1663: *
1664: * SEC START OF PROGRAM SECTION
1665: *
1666: * (PROGRAM SECTION)
1667: *
1668: * SEC START OF STACK OVERFLOW SECTION
1669: *
1670: * (STACK OVERFLOW SECTION)
1671: *
1672: * SEC START OF ERROR SECTION
1673: *
1674: * (ERROR SECTION)
1675: *
1676: * 14.2 END END OF ASSEMBLY
1677: EJC
1678: *
1679: * SECTION 10 - PROGRAM FORM
1680: *
1681: * PROCEDURE SECTION
1682: *
1683: * THE PROCEDURE SECTION CONTAINS ALL THE EXP
1684: * INSTRUCTIONS FOR EXTERNALLY AVAILABLE PROCEDURES
1685: * AND INP,INR OPCODES FOR INTERNAL PROCEDURES,ROUTINES
1686: * SO THAT A SINGLE PASS MINIMAL TRANSLATOR HAS ADVANCE
1687: * KNOWLEDGE OF PROCEDURE TYPES WHEN TRANSLATING CALLS.
1688: *
1689: * DEFINITIONS SECTION
1690: *
1691: * THE DEFINITIONS SECTION CONTAINS EQU INSTRUCTIONS
1692: * WHICH DEFINE SYMBOLS REFERENCED LATER ON IN THE
1693: * PROGRAM, CONSTANT AND WORK SECTIONS.
1694: *
1695: * CONSTANT STORAGE SECTION
1696: *
1697: * THE CONSTANT STORAGE SECTION CONSISTS ENTIRELY
1698: * OF CONSTANTS ASSEMBLED WITH THE DAC,DIC,DRC,DTC,DBC
1699: * ASSEMBLY OPERATIONS. THESE CONSTANTS CAN BE FREELY
1700: * REFERENCED BY THE PROGRAM INSTRUCTIONS.
1701: *
1702: * WORKING STORAGE SECTION
1703: *
1704: * THE WORKING STORAGE SECTION CONSISTS ENTIRELY OF
1705: * DAC,DIC,DRC,DBC,DTC INSTRUCTIONS TO DEFINE A FIXED
1706: * LENGTH WORK AREA. THE WORK LOCATIONS IN THIS AREA
1707: * CAN BE DIRECTLY REFERENCED IN PROGRAM INSTRUCTIONS.
1708: * THE AREA IS INITIALIZED IN ACCORDANCE WITH THE
1709: * VALUES ASSEMBLED IN THE INSTRUCTIONS.
1710: *
1711: * PROGRAM SECTION
1712: *
1713: * THE PROGRAM SECTION CONTAINS PROGRAM INSTRUCTIONS
1714: * AND ASSOCIATED OPERATIONS (SUCH AS PRC, ENP, ENT).
1715: * CONTROL IS PASSED TO THE FIRST INSTRUCTION IN THIS
1716: * SECTION WHEN EXECUTION IS INITIATED.
1717: *
1718: * STACK OVERFLOW SECTION
1719: *
1720: * THE STACK OVERFLOW SECTION CONTAINS INSTRUCTIONS
1721: * LIKE THE PROGRAM SECTION. CONTROL IS PASSED TO THE
1722: * FIRST INSTRUCTION IN THIS SECTION FOLLOWING THE
1723: * OCCURRENCE OF STACK OVERFLOW, SEE CHK INSTRUCTION.
1724: *
1725: * ERROR SECTION
1726: *
1727: * THE ERROR SECTION CONTAINS INSTRUCTIONS LIKE THE
1728: * PROGRAM SECTION. CONTROL IS PASSED TO THE FIRST
1729: * INSTRUCTION IN THIS SECTION WHEN A PROCEDURE EXIT
1730: * CORRESPONDS TO AN ERROR PARAMETER (SEE ERR)
1731: * OR WHEN AN ERB OPCODE IS OBEYED. THE ERROR CODE
1732: * MUST CLEAN UP THE MAIN STACK AND CATER FOR THE
1733: * POSSIBILITY THAT A SUBROUTINE STACK MAY NEED CLEAN
1734: * UP.
1735: EJC
1736: * OSINT
1737: *
1738: * THOUGH NOT PART OF THE MINIMAL SOURCE, IT IS USEFUL
1739: * TO REFER TO THE COLLECTION OF INITIALISATION AND
1740: * EXP ROUTINES AS OSINT (OPERATING SYSTEM INTERFACE).
1741: * ERRORS OCCURRING WITHIN OSINT PROCEDURES ARE
1742: * USUALLY HANDLED BY MAKING AN ERROR RETURN. IF THIS
1743: * IS NOT FEASIBLE OR APPROPRIATE, OSINT MAY USE THE
1744: * MINIMAL ERROR SECTION TO REPORT ERRORS DIRECTLY BY
1745: * BRANCHING TO IT WITH A SUITABLE NUMERIC ERROR
1746: * CODE IN WA.
1747: EJC
1748: *
1749: * SECTION 11 - STATEMENT FORMAT
1750: *
1751: * ALL LABELS ARE EXACTLY FIVE CHARACTERS LONG AND START
1752: * WITH THREE LETTERS (ABCDEFGHIJKLMNOPQRSTUVWXY$) FOLLOWED
1753: * BY TWO LETTERS OR DIGITS.
1754: * THE LETTER Z MAY NOT BE USED IN MINIMAL SYMBOLS BUT $ IS
1755: * PERMITTED.
1756: * FOR IMPLEMENTATIONS WHERE $ MAY NOT APPEAR IN THE
1757: * TARGET CODE , A SIMPLE SUBSTITUTION OF Z FOR $
1758: * MAY THUS BE MADE WITHOUT RISK OF PRODUCING NON-UNIQUE
1759: * SYMBOLS.
1760: * THE LETTER Z IS HOWEVER PERMITTED IN OPCODE MNEMONICS AND
1761: * IN COMMENTS.
1762: *
1763: * MINIMAL STATEMENTS ARE IN A FIXED FORMAT AS FOLLOWS.
1764: *
1765: * COLS 1-5 LABEL IF ANY (ELSE BLANK)
1766: *
1767: * COLS 6-7 ALWAYS BLANK
1768: *
1769: * COLS 8-10 OPERATION MNEMONIC
1770: *
1771: * COLS 11-12 BLANKS
1772: *
1773: * COLS 13-28 OPERAND FIELD, TERMINATED BY A
1774: * BLANK. MAY OCCASIONALLY
1775: * EXTEND PAST COLUMN 28.
1776: *
1777: * COLS 30-64 COMMENT. ALWAYS SEPARATED FROM THE
1778: * OPERAND FIELD BY AT LEAST ONE BLANK
1779: * MAY OCCASIONALLY START AFTER COLUMN
1780: * 30 IF THE OPERAND EXTENDS PAST 28.
1781: * A SPECIAL EXCEPTION OCCURS FOR THE
1782: * IFF INSTRUCTION, WHOSE COMMENT MAY
1783: * BE ONLY 20 CHARACTERS LONG (30-49).
1784: *
1785: * COLS 65 ON UNUSED
1786: *
1787: *
1788: * COMMENT LINES HAVE THE FOLLOWING FORMAT
1789: *
1790: * COL 1 ASTERISK
1791: *
1792: * COLS 2-7 BLANK
1793: *
1794: * COLS 8-64 ARBITRARY TEXT, RESTRICTED TO THE
1795: * FORTRAN CHARACTER SET.
1796: *
1797: *
1798: * THE FORTRAN CHARACTER SET IS A-Z 0-9 =,$.(*)-/+
1799: EJC
1800: *
1801: * SECTION 12 - PROGRAM EXECUTION
1802: *
1803: * EXECUTION OF THE PROGRAM BEGINS WITH THE FIRST
1804: * INSTRUCTION IN THE PROGRAM SECTION.
1805: *
1806: * IN ADDITION TO THE FIXED LENGTH MEMORY REGIONS DEFINED
1807: * BY THE ASSEMBLY, THERE ARE TWO DYNAMICALLY ALLOCATED
1808: * MEMORY REGIONS AS FOLLOWS.
1809: *
1810: * DATA AREA THIS IS AN AREA AVAILABLE TO THE
1811: * PROGRAM FOR GENERAL STORAGE OF DATA
1812: * ANY DATA VALUE MAY BE STORED IN
1813: * THIS AREA EXCEPT INSTRUCTIONS.
1814: * IN SOME IMPLEMENTATIONS, IT MAY BE
1815: * POSSIBLE TO INCREASE THE SIZE OF
1816: * THIS AREA DYNAMICALLY BY ADDING
1817: * WORDS AT THE TOP END WITH A CALL
1818: * TO A SYSTEM PROCEDURE.
1819: *
1820: * STACK AREA THIS REGION OF MEMORY HOLDS
1821: * THE STACK USED FOR SUBROUTINE CALLS
1822: * AND OTHER STORAGE OF ONE WORD
1823: * INTEGER VALUES (ADDRESSES). THIS
1824: * IS THE STACK ASSOCIATED WITH
1825: * INDEX REGISTER XS.
1826: *
1827: * THE LOCATIONS AND SIZES OF THESE AREAS ARE SPECIFIED
1828: * BY THE VALUES IN THE REGISTERS AT THE START OF PROGRAM
1829: * EXECUTION AS FOLLOWS.
1830: *
1831: * (XS) ADDRESS ONE PAST THE STACK BASE.
1832: * E.G. IF XS IS 23456, A D-STACK WILL
1833: * OCCUPY WORDS 23455,23454,...
1834: * WHEREAS A U-STACK WILL OCCUPY
1835: * 23457,23458,...
1836: *
1837: * (XR) ADDRESS OF THE FIRST WORD
1838: * IN THE DATA AREA
1839: *
1840: * (XL) ADDRESS OF THE LAST WORD IN THE
1841: * DATA AREA.
1842: *
1843: *
1844: * (WA,WB,WC,IA,RA,CP) ZERO
1845: *
1846: * THERE IS NO EXPLICIT WAY TO TERMINATE THE EXECUTION OF A
1847: * PROGRAM. THIS FUNCTION IS PERFORMED BY AN APPROPRIATE
1848: * SYSTEM PROCEDURE REFERENCED WITH THE SYSEJ INSTRUCTION.
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