-
Notifications
You must be signed in to change notification settings - Fork 11
/
Copy pathrabbit.html
722 lines (640 loc) · 21.4 KB
/
rabbit.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en">
<head>
<title>Rabbit VM RFC</title>
<!-- 2016-03-30 Wed 17:15 -->
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
<meta name="generator" content="Org-mode" />
<meta name="author" content="Maxwell Bernstein" />
<style type="text/css">
<!--/*--><![CDATA[/*><!--*/
.title { text-align: center; }
.todo { font-family: monospace; color: red; }
.done { color: green; }
.tag { background-color: #eee; font-family: monospace;
padding: 2px; font-size: 80%; font-weight: normal; }
.timestamp { color: #bebebe; }
.timestamp-kwd { color: #5f9ea0; }
.right { margin-left: auto; margin-right: 0px; text-align: right; }
.left { margin-left: 0px; margin-right: auto; text-align: left; }
.center { margin-left: auto; margin-right: auto; text-align: center; }
.underline { text-decoration: underline; }
#postamble p, #preamble p { font-size: 90%; margin: .2em; }
p.verse { margin-left: 3%; }
pre {
border: 1px solid #ccc;
box-shadow: 3px 3px 3px #eee;
padding: 8pt;
font-family: monospace;
overflow: auto;
margin: 1.2em;
}
pre.src {
position: relative;
overflow: visible;
padding-top: 1.2em;
}
pre.src:before {
display: none;
position: absolute;
background-color: white;
top: -10px;
right: 10px;
padding: 3px;
border: 1px solid black;
}
pre.src:hover:before { display: inline;}
pre.src-sh:before { content: 'sh'; }
pre.src-bash:before { content: 'sh'; }
pre.src-emacs-lisp:before { content: 'Emacs Lisp'; }
pre.src-R:before { content: 'R'; }
pre.src-perl:before { content: 'Perl'; }
pre.src-java:before { content: 'Java'; }
pre.src-sql:before { content: 'SQL'; }
table { border-collapse:collapse; }
caption.t-above { caption-side: top; }
caption.t-bottom { caption-side: bottom; }
td, th { vertical-align:top; }
th.right { text-align: center; }
th.left { text-align: center; }
th.center { text-align: center; }
td.right { text-align: right; }
td.left { text-align: left; }
td.center { text-align: center; }
dt { font-weight: bold; }
.footpara:nth-child(2) { display: inline; }
.footpara { display: block; }
.footdef { margin-bottom: 1em; }
.figure { padding: 1em; }
.figure p { text-align: center; }
.inlinetask {
padding: 10px;
border: 2px solid gray;
margin: 10px;
background: #ffffcc;
}
#org-div-home-and-up
{ text-align: right; font-size: 70%; white-space: nowrap; }
textarea { overflow-x: auto; }
.linenr { font-size: smaller }
.code-highlighted { background-color: #ffff00; }
.org-info-js_info-navigation { border-style: none; }
#org-info-js_console-label
{ font-size: 10px; font-weight: bold; white-space: nowrap; }
.org-info-js_search-highlight
{ background-color: #ffff00; color: #000000; font-weight: bold; }
/*]]>*/-->
</style>
<link rel="stylesheet" type="text/css" href="blogstyle.css" />
<script type="text/javascript">
/*
@licstart The following is the entire license notice for the
JavaScript code in this tag.
Copyright (C) 2012-2013 Free Software Foundation, Inc.
The JavaScript code in this tag is free software: you can
redistribute it and/or modify it under the terms of the GNU
General Public License (GNU GPL) as published by the Free Software
Foundation, either version 3 of the License, or (at your option)
any later version. The code is distributed WITHOUT ANY WARRANTY;
without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU GPL for more details.
As additional permission under GNU GPL version 3 section 7, you
may distribute non-source (e.g., minimized or compacted) forms of
that code without the copy of the GNU GPL normally required by
section 4, provided you include this license notice and a URL
through which recipients can access the Corresponding Source.
@licend The above is the entire license notice
for the JavaScript code in this tag.
*/
<!--/*--><![CDATA[/*><!--*/
function CodeHighlightOn(elem, id)
{
var target = document.getElementById(id);
if(null != target) {
elem.cacheClassElem = elem.className;
elem.cacheClassTarget = target.className;
target.className = "code-highlighted";
elem.className = "code-highlighted";
}
}
function CodeHighlightOff(elem, id)
{
var target = document.getElementById(id);
if(elem.cacheClassElem)
elem.className = elem.cacheClassElem;
if(elem.cacheClassTarget)
target.className = elem.cacheClassTarget;
}
/*]]>*///-->
</script>
</head>
<body>
<div id="content">
<h1 class="title">Rabbit VM RFC</h1>
<div id="table-of-contents">
<h2>Table of Contents</h2>
<div id="text-table-of-contents">
<ul>
<li><a href="#sec-1">1. Why?</a></li>
<li><a href="#sec-2">2. What?</a>
<ul>
<li><a href="#sec-2-1">2.1. Definitions</a></li>
<li><a href="#sec-2-2">2.2. Registers</a>
<ul>
<li><a href="#sec-2-2-1">2.2.1. Flags</a></li>
</ul>
</li>
<li><a href="#sec-2-3">2.3. Instruction set</a>
<ul>
<li><a href="#sec-2-3-1">2.3.1. Real instructions</a></li>
<li><a href="#sec-2-3-2">2.3.2. Assembler macros</a></li>
</ul>
</li>
<li><a href="#sec-2-4">2.4. Addressing modes</a></li>
</ul>
</li>
<li><a href="#sec-3">3. How?</a>
<ul>
<li><a href="#sec-3-1">3.1. Instruction formats</a></li>
<li><a href="#sec-3-2">3.2. Stages of compilation</a>
<ul>
<li><a href="#sec-3-2-1">3.2.1. <span class="todo TODO">TODO</span> Preprocessing</a></li>
<li><a href="#sec-3-2-2">3.2.2. <span class="todo TODO">TODO</span> Peephole optimization</a></li>
<li><a href="#sec-3-2-3">3.2.3. <span class="todo TODO">TODO</span> Assembling</a></li>
</ul>
</li>
<li><a href="#sec-3-3">3.3. <span class="todo TODO">TODO</span> </a>
<ul>
<li><a href="#sec-3-3-1">3.3.1. Floating point</a></li>
<li><a href="#sec-3-3-2">3.3.2. Memory layout</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
<div id="outline-container-sec-1" class="outline-2">
<h2 id="sec-1"><span class="section-number-2">1</span> Why?</h2>
<div class="outline-text-2" id="text-1">
<p>
I would like to make a RISC architecture that is capable of comfortably sitting
on top of nearly any other architecture. If it's possible to compile to Rabbit,
then a program can run on more or less any hardware or virtualized architecture.
</p>
<p>
Rabbit can be optimized per-architecture, while maintaining the same
interface. It may, for example, take advantage of Intel's SIMD behind the
scenes.
</p>
</div>
</div>
<div id="outline-container-sec-2" class="outline-2">
<h2 id="sec-2"><span class="section-number-2">2</span> What?</h2>
<div class="outline-text-2" id="text-2">
</div><div id="outline-container-sec-2-1" class="outline-3">
<h3 id="sec-2-1"><span class="section-number-3">2.1</span> Definitions</h3>
<div class="outline-text-3" id="text-2-1">
<p>
<b>space:</b> A register or memory location.
</p>
</div>
</div>
<div id="outline-container-sec-2-2" class="outline-3">
<h3 id="sec-2-2"><span class="section-number-3">2.2</span> Registers</h3>
<div class="outline-text-3" id="text-2-2">
<p>
Registers are 32 bits wide.
</p>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<colgroup>
<col class="left" />
<col class="left" />
<col class="left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="left"><i>Value</i></th>
<th scope="col" class="left"><i>Register</i></th>
<th scope="col" class="left"><i>Use</i></th>
</tr>
</thead>
<tbody>
<tr>
<td class="left"><code>0x0</code></td>
<td class="left"><code>zero</code></td>
<td class="left">Contains 0. MIPS style.</td>
</tr>
<tr>
<td class="left"><code>0x1</code> .. <code>0x9</code></td>
<td class="left"><code>r1</code> .. <code>r9</code></td>
<td class="left">General purpose.</td>
</tr>
<tr>
<td class="left"><code>0xA</code></td>
<td class="left"><code>ip</code></td>
<td class="left">Instruction pointer.</td>
</tr>
<tr>
<td class="left"><code>0xB</code></td>
<td class="left"><code>sp</code></td>
<td class="left">Stack pointer.</td>
</tr>
<tr>
<td class="left"><code>0xC</code></td>
<td class="left"><code>ret</code></td>
<td class="left">Returned value.</td>
</tr>
<tr>
<td class="left"><code>0xD</code></td>
<td class="left"><code>tmp</code></td>
<td class="left">Temporary register.</td>
</tr>
<tr>
<td class="left"><code>0xE</code></td>
<td class="left"><code>flags</code></td>
<td class="left">Flags used for comparison.</td>
</tr>
</tbody>
</table>
<p>
<a id="flags_section" name="flags_section"></a>
</p>
</div>
<div id="outline-container-sec-2-2-1" class="outline-4">
<h4 id="sec-2-2-1"><span class="section-number-4">2.2.1</span> Flags</h4>
<div class="outline-text-4" id="text-2-2-1">
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<colgroup>
<col class="left" />
<col class="left" />
<col class="left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="left"><i>Bit</i></th>
<th scope="col" class="left"><i>Flag</i></th>
<th scope="col" class="left"><i>Meaning</i></th>
</tr>
</thead>
<tbody>
<tr>
<td class="left"><code>0x0</code></td>
<td class="left"><code>SF</code></td>
<td class="left">Sign flag. On if sign bit of result is on.</td>
</tr>
<tr>
<td class="left"><code>0x1</code></td>
<td class="left"><code>ZF</code></td>
<td class="left">Zero flag. On if result is zero or numbers were the same.</td>
</tr>
<tr>
<td class="left"><code>0x2</code> .. <code>0x20</code></td>
<td class="left"> </td>
<td class="left">Reserved.</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
<div id="outline-container-sec-2-3" class="outline-3">
<h3 id="sec-2-3"><span class="section-number-3">2.3</span> Instruction set</h3>
<div class="outline-text-3" id="text-2-3">
</div><div id="outline-container-sec-2-3-1" class="outline-4">
<h4 id="sec-2-3-1"><span class="section-number-4">2.3.1</span> Real instructions</h4>
<div class="outline-text-4" id="text-2-3-1">
<p>
When it makes sense, the destination register is the first argument to an
instruction. The last argument to the following instructions may also be an
immediate value, denoted with a prefix of <code>$</code>: <code>move</code>, <code>add</code>, <code>sub</code>, <code>mul</code>, <code>div</code>,
<code>shr</code>, <code>shl</code>, <code>nand</code>, <code>xor</code>, <code>br</code>, <code>brz</code>, <code>brnz</code>.
</p>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<colgroup>
<col class="left" />
<col class="left" />
<col class="left" />
<col class="left" />
<col class="left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="left"><i>Value</i></th>
<th scope="col" class="left"><i>Instruction</i></th>
<th scope="col" class="left"><i>Usage</i></th>
<th scope="col" class="left"><i>Explanation</i></th>
<th scope="col" class="left"><i>Description</i></th>
</tr>
</thead>
<tbody>
<tr>
<td class="left"><code>0x0</code></td>
<td class="left"><code>halt</code></td>
<td class="left"><code>halt</code></td>
<td class="left"> </td>
<td class="left">Stop the execution of the machine immediately.</td>
</tr>
<tr>
<td class="left"><code>0x1</code></td>
<td class="left"><code>move</code></td>
<td class="left"><code>move %rB, %rC</code></td>
<td class="left"><code>r[B] := r[C]</code></td>
<td class="left">Move one space into another.</td>
</tr>
<tr>
<td class="left"><code>0x2</code></td>
<td class="left"><code>add</code></td>
<td class="left"><code>add %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := r[B] + r[C]</code></td>
<td class="left">Add two spaces into a third.</td>
</tr>
<tr>
<td class="left"><code>0x3</code></td>
<td class="left"><code>sub</code></td>
<td class="left"><code>sub %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := r[B] - r[C]</code></td>
<td class="left">Subtract two spaces into a third. Sets <a href="#flags_section">flags</a>.</td>
</tr>
<tr>
<td class="left"><code>0x4</code></td>
<td class="left"><code>mul</code></td>
<td class="left"><code>mul %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := r[B] * r[C]</code></td>
<td class="left">Multiply two spaces into a third.</td>
</tr>
<tr>
<td class="left"><code>0x5</code></td>
<td class="left"><code>div</code></td>
<td class="left"><code>div %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := r[B] / r[C]</code></td>
<td class="left">Divide two spaces into a third.</td>
</tr>
<tr>
<td class="left"><code>0x6</code></td>
<td class="left"><code>shr</code></td>
<td class="left"><code>shr %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := r[B] >> r[C]</code></td>
<td class="left">Shift right one space a number of times.</td>
</tr>
<tr>
<td class="left"><code>0x7</code></td>
<td class="left"><code>shl</code></td>
<td class="left"><code>shl %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := r[B] << r[C]</code></td>
<td class="left">Shift left one space a number of times.</td>
</tr>
<tr>
<td class="left"><code>0x8</code></td>
<td class="left"><code>nand</code></td>
<td class="left"><code>nand %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := not(r[B] & r[C])</code></td>
<td class="left">NAND two spaces.</td>
</tr>
<tr>
<td class="left"><code>0x9</code></td>
<td class="left"><code>xor</code></td>
<td class="left"><code>xor %rA, %rB, %rC</code></td>
<td class="left"><code>r[A] := r[B] ^ r[C]</code></td>
<td class="left">XOR two spaces.</td>
</tr>
<tr>
<td class="left"><code>0xA</code></td>
<td class="left"><code>br</code></td>
<td class="left"><code>br %rC</code></td>
<td class="left"><code>goto r[C]</code></td>
<td class="left">Branch.</td>
</tr>
<tr>
<td class="left"><code>0xB</code></td>
<td class="left"><code>brz</code></td>
<td class="left"><code>brz %rC</code></td>
<td class="left"><code>if (ZF set) goto r[C]</code></td>
<td class="left">Branch if <code>ZF</code> is set.</td>
</tr>
<tr>
<td class="left"><code>0xC</code></td>
<td class="left"><code>brnz</code></td>
<td class="left"><code>brnz %rC</code></td>
<td class="left"><code>if (!(ZF set)) goto r[C]</code></td>
<td class="left">Branch if <code>ZF</code> is not set.</td>
</tr>
<tr>
<td class="left"><code>0xD</code></td>
<td class="left"><code>in</code></td>
<td class="left"><code>in %rC</code></td>
<td class="left"><code>r[C] := getchar()</code></td>
<td class="left">Read one character from <code>stdin</code> into a space.</td>
</tr>
<tr>
<td class="left"><code>0xE</code></td>
<td class="left"><code>out</code></td>
<td class="left"><code>out %rC</code></td>
<td class="left"><code>putchar(r[C])</code></td>
<td class="left">Print one character from a space to <code>stdout</code>.</td>
</tr>
</tbody>
</table>
</div>
</div>
<div id="outline-container-sec-2-3-2" class="outline-4">
<h4 id="sec-2-3-2"><span class="section-number-4">2.3.2</span> Assembler macros</h4>
<div class="outline-text-4" id="text-2-3-2">
<p>
The last argument to the following macros may also be an immediate value,
denoted with a prefix of <code>$</code>: <code>cmp</code>, <code>not</code>, <code>push</code>, <code>call</code>.
</p>
<table border="2" cellspacing="0" cellpadding="6" rules="groups" frame="hsides">
<colgroup>
<col class="left" />
<col class="left" />
<col class="left" />
</colgroup>
<thead>
<tr>
<th scope="col" class="left"><i>Macro</i></th>
<th scope="col" class="left"><i>Usage</i></th>
<th scope="col" class="left"><i>Expansion</i></th>
</tr>
</thead>
<tbody>
<tr>
<td class="left"><code>cmp</code></td>
<td class="left"><code>cmp A, B</code></td>
<td class="left"><code>sub %tmp, A, B</code></td>
</tr>
<tr>
<td class="left"><code>not</code></td>
<td class="left"><code>not A, B</code></td>
<td class="left"><code>nand A, B, B</code></td>
</tr>
<tr>
<td class="left"><code>or</code></td>
<td class="left"><code>or A, B, C</code></td>
<td class="left"><code>(A nand A) nand (B nand B)</code></td>
</tr>
<tr>
<td class="left"><code>and</code></td>
<td class="left"><code>and A, B, C</code></td>
<td class="left"><code>nand A, B, C</code> // <code>not A, A</code></td>
</tr>
<tr>
<td class="left"><code>push</code></td>
<td class="left"><code>push A</code></td>
<td class="left"><code>move (%sp), A</code> // <code>sub %sp, %sp, $1</code></td>
</tr>
<tr>
<td class="left"><code>pop</code></td>
<td class="left"><code>pop A</code></td>
<td class="left"><code>add %sp, %sp, $1</code> // <code>move A, (%sp)</code></td>
</tr>
<tr>
<td class="left"><code>call</code></td>
<td class="left"><code>call A</code></td>
<td class="left"><code>push %ip</code> // <code>br A</code></td>
</tr>
<tr>
<td class="left"><code>ret</code></td>
<td class="left"><code>ret</code></td>
<td class="left"><code>pop %ip</code></td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
<div id="outline-container-sec-2-4" class="outline-3">
<h3 id="sec-2-4"><span class="section-number-3">2.4</span> Addressing modes</h3>
<div class="outline-text-3" id="text-2-4">
<p>
There are two addressing modes: <code>%reg</code> and <code>(%reg)</code>. The former uses the value
in the register, and the latter uses the word at the address in the register.
</p>
</div>
</div>
</div>
<div id="outline-container-sec-3" class="outline-2">
<h2 id="sec-3"><span class="section-number-2">3</span> How?</h2>
<div class="outline-text-2" id="text-3">
</div><div id="outline-container-sec-3-1" class="outline-3">
<h3 id="sec-3-1"><span class="section-number-3">3.1</span> Instruction formats</h3>
<div class="outline-text-3" id="text-3-1">
<pre class="example">
instr %rA, %rB, %rC
instr %rA, %rB
instr %rA
</pre>
<pre class="example">
+-----Immediate bit
|+----Addressing mode bit C
||+---Addressing mode bit B
|||+--Addressing mode bit A
|||| +Dead space+ regB
vvvv vvvvvvvvvvvv vvvv
IIII MDDD 000000000000 CCCCBBBBAAAA
^^^^ ^^^^ ^^^^
Opcode regC regA
VVVVVVVVVVVVVVVVVVVVVVVVVVVVVVVV
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Immediate value
</pre>
<p>
Every bit in "Dead space" must be turned off. If one is turned on, the result
is undefined.
</p>
<p>
If the immediate bit is on, then the instruction disregards <code>rC</code> and instead
looks for its third argument in the 32 bits after the first instruction. For example:
</p>
<pre class="example">
1: 0001 1 000 000000000000 0001 0000 0000
2: 0000 0 000 000000000000 0000 0000 0111
</pre>
<p>
represents a <code>move</code> instruction with the immediate bit set. It will therefore
look for an immediate value in the following word (in this case, the value is
7), and then store it in <code>r1</code>.
</p>
<p>
Addition works in a similar fashion:
</p>
<pre class="example">
1: 0010 1 000 000000000000 0001 0001 0000
2: 0000 0 000 000000000000 0000 0000 0001
</pre>
<p>
represents an <code>add</code> instruction with the immediate bit set. It looks for an
immediate value in the following word (in this case, 1), adds it to the value in
<code>r1</code>, then stores the result in <code>r1</code>. So this instruction would be an increment
instruction.
</p>
<p>
The addressing mode bits are simple; if a register's addressing mode bit is on,
then the address in the register is dereferenced when the instruction is being
executed, and that data is used instead. For example:
</p>
<pre class="example">
1: 0010 0 100 000000000000 0111 0001 0000
</pre>
<p>
Performs an addition operation that adds the contents of <code>zero</code> with <code>r1</code> and
stores the result in memory at the address in <code>r7</code>.
</p>
</div>
</div>
<div id="outline-container-sec-3-2" class="outline-3">
<h3 id="sec-3-2"><span class="section-number-3">3.2</span> Stages of compilation</h3>
<div class="outline-text-3" id="text-3-2">
</div><div id="outline-container-sec-3-2-1" class="outline-4">
<h4 id="sec-3-2-1"><span class="section-number-4">3.2.1</span> <span class="todo TODO">TODO</span> Preprocessing</h4>
<div class="outline-text-4" id="text-3-2-1">
<p>
The preprocessor will be responsible for macro expansion and label to address
translation. Macros exist in the form of instruction expansions, done behind the
scenes.
</p>
</div>
</div>
<div id="outline-container-sec-3-2-2" class="outline-4">
<h4 id="sec-3-2-2"><span class="section-number-4">3.2.2</span> <span class="todo TODO">TODO</span> Peephole optimization</h4>
</div>
<div id="outline-container-sec-3-2-3" class="outline-4">
<h4 id="sec-3-2-3"><span class="section-number-4">3.2.3</span> <span class="todo TODO">TODO</span> Assembling</h4>
<div class="outline-text-4" id="text-3-2-3">
</div>
</div>
</div>
<div id="outline-container-sec-3-3" class="outline-3">
<h3 id="sec-3-3"><span class="section-number-3">3.3</span> <span class="todo TODO">TODO</span> </h3>
<div class="outline-text-3" id="text-3-3">
</div><div id="outline-container-sec-3-3-1" class="outline-4">
<h4 id="sec-3-3-1"><span class="section-number-4">3.3.1</span> Floating point</h4>
<div class="outline-text-4" id="text-3-3-1">
<p>
Floating point computation is left to the client (an exercise for the reader, if
you will).
</p>
</div>
</div>
<div id="outline-container-sec-3-3-2" class="outline-4">
<h4 id="sec-3-3-2"><span class="section-number-4">3.3.2</span> Memory layout</h4>
<div class="outline-text-4" id="text-3-3-2">
<p>
The memory layout is completely flat right now.
</p>
</div>
</div>
</div>
</div>
</div>
<div id="postamble" class="status">
<p class="date">Date: March 29, 2016</p>
<p class="author">Author: Maxwell Bernstein</p>
<p class="date">Created: 2016-03-30 Wed 17:15</p>
<p class="creator"><a href="http://www.gnu.org/software/emacs/">Emacs</a> 24.5.1 (<a href="http://orgmode.org">Org</a> mode 8.2.10)</p>
<p class="validation"><a href="http://validator.w3.org/check?uri=referer">Validate</a></p>
</div>
</body>
</html>