about summary refs log tree commit diff stats
path: root/html/412render-float-decimal.mu.html
blob: 81a6dd38b41111310741fa040f2cb4497d6e435a (plain) (blame)
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
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Mu - 412render-float-decimal.mu</title>
<meta name="Generator" content="Vim/8.1">
<meta name="plugin-version" content="vim8.1_v1">
<meta name="syntax" content="none">
<meta name="settings" content="number_lines,use_css,pre_wrap,no_foldcolumn,expand_tabs,line_ids,prevent_copy=">
<meta name="colorscheme" content="minimal-light">
<style type="text/css">
<!--
pre { white-space: pre-wrap; font-family: monospace; color: #000000; background-color: #eeeeee; }
body { font-size:12pt; font-family: monospace; color: #000000; background-color: #eeeeee; }
a { color:inherit; }
* { font-size:12pt; font-size: 1em; }
.LineNr { }
.Delimiter { color: #c000c0; }
.muRegEdx { color: #878700; }
.muRegEbx { color: #8787af; }
.muRegEsi { color: #87d787; }
.muRegEdi { color: #87ffd7; }
.Constant { color: #008787; }
.Special { color: #ff6060; }
.PreProc { color: #c000c0; }
.muFunction { color: #af5f00; text-decoration: underline; }
.muTest { color: #5f8700; }
.muComment { color: #005faf; }
.muRegEax { color: #875f00; }
.muRegEcx { color: #af875f; }
-->
</style>

<script type='text/javascript'>
<!--

/* function to open any folds containing a jumped-to line before jumping to it */
function JumpToLine()
{
  var lineNum;
  lineNum = window.location.hash;
  lineNum = lineNum.substr(1); /* strip off '#' */

  if (lineNum.indexOf('L') == -1) {
    lineNum = 'L'+lineNum;
  }
  var lineElem = document.getElementById(lineNum);
  /* Always jump to new location even if the line was hidden inside a fold, or
   * we corrected the raw number to a line ID.
   */
  if (lineElem) {
    lineElem.scrollIntoView(true);
  }
  return true;
}
if ('onhashchange' in window) {
  window.onhashchange = JumpToLine;
}

-->
</script>
</head>
<body onload='JumpToLine();'>
<a href='https://github.com/akkartik/mu/blob/main/412render-float-decimal.mu'>https://github.com/akkartik/mu/blob/main/412render-float-decimal.mu</a>
<pre id='vimCodeElement'>
<span id="L1" class="LineNr">  1 </span><span class="muComment"># print out floats in decimal</span>
<span id="L2" class="LineNr">  2 </span><span class="muComment"># <a href="https://research.swtch.com/ftoa">https://research.swtch.com/ftoa</a></span>
<span id="L3" class="LineNr">  3 </span><span class="muComment">#</span>
<span id="L4" class="LineNr">  4 </span><span class="muComment"># Basic idea:</span>
<span id="L5" class="LineNr">  5 </span><span class="muComment">#   Ignoring sign, floating point numbers are represented as 1.mantissa * 2^exponent</span>
<span id="L6" class="LineNr">  6 </span><span class="muComment">#   Therefore, to print a float in decimal, we need to:</span>
<span id="L7" class="LineNr">  7 </span><span class="muComment">#     - compute its value without decimal point</span>
<span id="L8" class="LineNr">  8 </span><span class="muComment">#     - convert to an array of decimal digits</span>
<span id="L9" class="LineNr">  9 </span><span class="muComment">#     - print out the array while inserting the decimal point appropriately</span>
<span id="L10" class="LineNr"> 10 </span><span class="muComment">#</span>
<span id="L11" class="LineNr"> 11 </span><span class="muComment"># Basic complication: the computation generates numbers larger than an int can</span>
<span id="L12" class="LineNr"> 12 </span><span class="muComment"># hold. We need a way to represent big ints.</span>
<span id="L13" class="LineNr"> 13 </span><span class="muComment">#</span>
<span id="L14" class="LineNr"> 14 </span><span class="muComment"># Key insight: use a representation for big ints that's close to what we need</span>
<span id="L15" class="LineNr"> 15 </span><span class="muComment"># anyway, an array of decimal digits.</span>
<span id="L16" class="LineNr"> 16 </span><span class="muComment">#</span>
<span id="L17" class="LineNr"> 17 </span><span class="muComment"># Style note: we aren't creating a big int library here. The only operations</span>
<span id="L18" class="LineNr"> 18 </span><span class="muComment"># we need are halving and doubling. Following the link above, it seems more</span>
<span id="L19" class="LineNr"> 19 </span><span class="muComment"># comprehensible to keep these operations inlined so that we can track the</span>
<span id="L20" class="LineNr"> 20 </span><span class="muComment"># position of the decimal point with dispatch.</span>
<span id="L21" class="LineNr"> 21 </span><span class="muComment">#</span>
<span id="L22" class="LineNr"> 22 </span><span class="muComment"># This approach turns out to be fast enough for most purposes.</span>
<span id="L23" class="LineNr"> 23 </span><span class="muComment"># Optimizations, however, get wildly more complex.</span>
<span id="L24" class="LineNr"> 24 </span>
<span id="L25" class="LineNr"> 25 </span><span class="PreProc">fn</span> <span class="muTest"><a href='412render-float-decimal.mu.html#L25'>test-write-float-decimal-approximate-normal</a></span> <span class="Delimiter">{</span>
<span id="L26" class="LineNr"> 26 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L27" class="LineNr"> 27 </span>  <span class="PreProc">var</span> s/<span class="muRegEcx">ecx</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L28" class="LineNr"> 28 </span>  <span class="muComment"># 0.5</span>
<span id="L29" class="LineNr"> 29 </span>  <span class="PreProc">var</span> half/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">1</span>, <span class="Constant">2</span>
<span id="L30" class="LineNr"> 30 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, half, <span class="Constant">3</span>
<span id="L31" class="LineNr"> 31 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;0.5&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L25'>test-write-float-decimal-approximate-normal</a> 0.5&quot;</span>
<span id="L32" class="LineNr"> 32 </span>  <span class="muComment"># 0.25</span>
<span id="L33" class="LineNr"> 33 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L34" class="LineNr"> 34 </span>  <span class="PreProc">var</span> quarter/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">1</span>, <span class="Constant">4</span>
<span id="L35" class="LineNr"> 35 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, quarter, <span class="Constant">3</span>
<span id="L36" class="LineNr"> 36 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;0.25&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L25'>test-write-float-decimal-approximate-normal</a> 0.25&quot;</span>
<span id="L37" class="LineNr"> 37 </span>  <span class="muComment"># 0.75</span>
<span id="L38" class="LineNr"> 38 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L39" class="LineNr"> 39 </span>  <span class="PreProc">var</span> three-quarters/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">3</span>, <span class="Constant">4</span>
<span id="L40" class="LineNr"> 40 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, three-quarters, <span class="Constant">3</span>
<span id="L41" class="LineNr"> 41 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;0.75&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L25'>test-write-float-decimal-approximate-normal</a> 0.75&quot;</span>
<span id="L42" class="LineNr"> 42 </span>  <span class="muComment"># 0.125</span>
<span id="L43" class="LineNr"> 43 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L44" class="LineNr"> 44 </span>  <span class="PreProc">var</span> eighth/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">1</span>, <span class="Constant">8</span>
<span id="L45" class="LineNr"> 45 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, eighth, <span class="Constant">3</span>
<span id="L46" class="LineNr"> 46 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;0.125&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L25'>test-write-float-decimal-approximate-normal</a> 0.125&quot;</span>
<span id="L47" class="LineNr"> 47 </span>  <span class="muComment"># 0.0625; start using scientific notation</span>
<span id="L48" class="LineNr"> 48 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L49" class="LineNr"> 49 </span>  <span class="PreProc">var</span> sixteenth/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">1</span>, <span class="Constant">0x10</span>
<span id="L50" class="LineNr"> 50 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, sixteenth, <span class="Constant">3</span>
<span id="L51" class="LineNr"> 51 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;6.25e-2&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L25'>test-write-float-decimal-approximate-normal</a> 0.0625&quot;</span>
<span id="L52" class="LineNr"> 52 </span>  <span class="muComment"># sqrt(2); truncate floats with lots of digits after the decimal but not too many before</span>
<span id="L53" class="LineNr"> 53 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L54" class="LineNr"> 54 </span>  <span class="PreProc">var</span> two-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">2</span>, <span class="Constant">1</span>
<span id="L55" class="LineNr"> 55 </span>  <span class="PreProc">var</span> sqrt-2/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> square-root two-f
<span id="L56" class="LineNr"> 56 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, sqrt-2, <span class="Constant">3</span>
<span id="L57" class="LineNr"> 57 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;1.414&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L25'>test-write-float-decimal-approximate-normal</a> √2&quot;</span>
<span id="L58" class="LineNr"> 58 </span><span class="Delimiter">}</span>
<span id="L59" class="LineNr"> 59 </span>
<span id="L60" class="LineNr"> 60 </span><span class="muComment"># print whole integers without decimals</span>
<span id="L61" class="LineNr"> 61 </span><span class="PreProc">fn</span> <span class="muTest"><a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a></span> <span class="Delimiter">{</span>
<span id="L62" class="LineNr"> 62 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L63" class="LineNr"> 63 </span>  <span class="PreProc">var</span> s/<span class="muRegEcx">ecx</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L64" class="LineNr"> 64 </span>  <span class="muComment"># 1</span>
<span id="L65" class="LineNr"> 65 </span>  <span class="PreProc">var</span> one-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">1</span>, <span class="Constant">1</span>
<span id="L66" class="LineNr"> 66 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, one-f, <span class="Constant">3</span>
<span id="L67" class="LineNr"> 67 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;1&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a> 1&quot;</span>
<span id="L68" class="LineNr"> 68 </span>  <span class="muComment"># 2</span>
<span id="L69" class="LineNr"> 69 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L70" class="LineNr"> 70 </span>  <span class="PreProc">var</span> two-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">2</span>, <span class="Constant">1</span>
<span id="L71" class="LineNr"> 71 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, two-f, <span class="Constant">3</span>
<span id="L72" class="LineNr"> 72 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;2&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a> 2&quot;</span>
<span id="L73" class="LineNr"> 73 </span>  <span class="muComment"># 10</span>
<span id="L74" class="LineNr"> 74 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L75" class="LineNr"> 75 </span>  <span class="PreProc">var</span> ten-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">0xa</span>, <span class="Constant">1</span>
<span id="L76" class="LineNr"> 76 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, ten-f, <span class="Constant">3</span>
<span id="L77" class="LineNr"> 77 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;10&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a> 10&quot;</span>
<span id="L78" class="LineNr"> 78 </span>  <span class="muComment"># -10</span>
<span id="L79" class="LineNr"> 79 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L80" class="LineNr"> 80 </span>  <span class="PreProc">var</span> minus-ten-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">-0xa</span>, <span class="Constant">1</span>
<span id="L81" class="LineNr"> 81 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, minus-ten-f, <span class="Constant">3</span>
<span id="L82" class="LineNr"> 82 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;-10&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a> -10&quot;</span>
<span id="L83" class="LineNr"> 83 </span>  <span class="muComment"># 999</span>
<span id="L84" class="LineNr"> 84 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L85" class="LineNr"> 85 </span>  <span class="PreProc">var</span> minus-ten-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">0x3e7</span>, <span class="Constant">1</span>
<span id="L86" class="LineNr"> 86 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, minus-ten-f, <span class="Constant">3</span>
<span id="L87" class="LineNr"> 87 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;999&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a> 1000&quot;</span>
<span id="L88" class="LineNr"> 88 </span>  <span class="muComment"># 1000 - start using scientific notation</span>
<span id="L89" class="LineNr"> 89 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L90" class="LineNr"> 90 </span>  <span class="PreProc">var</span> minus-ten-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> <a href='408float.mu.html#L18'>rational</a> <span class="Constant">0x3e8</span>, <span class="Constant">1</span>
<span id="L91" class="LineNr"> 91 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, minus-ten-f, <span class="Constant">3</span>
<span id="L92" class="LineNr"> 92 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;1.00e3&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a> 1000&quot;</span>
<span id="L93" class="LineNr"> 93 </span>  <span class="muComment"># 100,000</span>
<span id="L94" class="LineNr"> 94 </span>  <a href='106stream.subx.html#L20'>clear-stream</a> s
<span id="L95" class="LineNr"> 95 </span>  <span class="PreProc">var</span> hundred-thousand/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0x186a0</span>
<span id="L96" class="LineNr"> 96 </span>  <span class="PreProc">var</span> hundred-thousand-f/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> convert hundred-thousand
<span id="L97" class="LineNr"> 97 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, hundred-thousand-f, <span class="Constant">3</span>
<span id="L98" class="LineNr"> 98 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;1.00e5&quot;</span>, <span class="Constant">&quot;F - <a href='412render-float-decimal.mu.html#L61'>test-write-float-decimal-approximate-integer</a> 100,000&quot;</span>
<span id="L99" class="LineNr"> 99 </span><span class="Delimiter">}</span>
<span id="L100" class="LineNr">100 </span>
<span id="L101" class="LineNr">101 </span><span class="PreProc">fn</span> <span class="muTest"><a href='412render-float-decimal.mu.html#L101'>test-write-float-decimal-approximate-zero</a></span> <span class="Delimiter">{</span>
<span id="L102" class="LineNr">102 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L103" class="LineNr">103 </span>  <span class="PreProc">var</span> s/<span class="muRegEcx">ecx</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L104" class="LineNr">104 </span>  <span class="PreProc">var</span> zero: float
<span id="L105" class="LineNr">105 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, zero, <span class="Constant">3</span>
<span id="L106" class="LineNr">106 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;0&quot;</span>, <span class="Constant">&quot;F - test-write-float-decimal-approximate-zero&quot;</span>
<span id="L107" class="LineNr">107 </span><span class="Delimiter">}</span>
<span id="L108" class="LineNr">108 </span>
<span id="L109" class="LineNr">109 </span><span class="PreProc">fn</span> <span class="muTest"><a href='412render-float-decimal.mu.html#L109'>test-write-float-decimal-approximate-negative-zero</a></span> <span class="Delimiter">{</span>
<span id="L110" class="LineNr">110 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L111" class="LineNr">111 </span>  <span class="PreProc">var</span> s/<span class="muRegEcx">ecx</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L112" class="LineNr">112 </span>  <span class="PreProc">var</span> n: int
<span id="L113" class="LineNr">113 </span>  copy-to n, <span class="Constant">0x80000000</span>
<span id="L114" class="LineNr">114 </span>  <span class="PreProc">var</span> negative-zero/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> reinterpret n
<span id="L115" class="LineNr">115 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, negative-zero, <span class="Constant">3</span>
<span id="L116" class="LineNr">116 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;-0&quot;</span>, <span class="Constant">&quot;F - test-write-float-decimal-approximate-negative-zero&quot;</span>
<span id="L117" class="LineNr">117 </span><span class="Delimiter">}</span>
<span id="L118" class="LineNr">118 </span>
<span id="L119" class="LineNr">119 </span><span class="PreProc">fn</span> <span class="muTest"><a href='412render-float-decimal.mu.html#L119'>test-write-float-decimal-approximate-infinity</a></span> <span class="Delimiter">{</span>
<span id="L120" class="LineNr">120 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L121" class="LineNr">121 </span>  <span class="PreProc">var</span> s/<span class="muRegEcx">ecx</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L122" class="LineNr">122 </span>  <span class="PreProc">var</span> n: int
<span id="L123" class="LineNr">123 </span>  <span class="muComment">#          0|11111111|00000000000000000000000</span>
<span id="L124" class="LineNr">124 </span>  <span class="muComment">#          0111|1111|1000|0000|0000|0000|0000|0000</span>
<span id="L125" class="LineNr">125 </span>  copy-to n, <span class="Constant">0x7f800000</span>
<span id="L126" class="LineNr">126 </span>  <span class="PreProc">var</span> infinity/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> reinterpret n
<span id="L127" class="LineNr">127 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, infinity, <span class="Constant">3</span>
<span id="L128" class="LineNr">128 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;Inf&quot;</span>, <span class="Constant">&quot;F - test-write-float-decimal-approximate-infinity&quot;</span>
<span id="L129" class="LineNr">129 </span><span class="Delimiter">}</span>
<span id="L130" class="LineNr">130 </span>
<span id="L131" class="LineNr">131 </span><span class="PreProc">fn</span> <span class="muTest"><a href='412render-float-decimal.mu.html#L131'>test-write-float-decimal-approximate-negative-infinity</a></span> <span class="Delimiter">{</span>
<span id="L132" class="LineNr">132 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L133" class="LineNr">133 </span>  <span class="PreProc">var</span> s/<span class="muRegEcx">ecx</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L134" class="LineNr">134 </span>  <span class="PreProc">var</span> n: int
<span id="L135" class="LineNr">135 </span>  copy-to n, <span class="Constant">0xff800000</span>
<span id="L136" class="LineNr">136 </span>  <span class="PreProc">var</span> negative-infinity/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> reinterpret n
<span id="L137" class="LineNr">137 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, negative-infinity, <span class="Constant">3</span>
<span id="L138" class="LineNr">138 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;-Inf&quot;</span>, <span class="Constant">&quot;F - test-write-float-decimal-approximate-negative-infinity&quot;</span>
<span id="L139" class="LineNr">139 </span><span class="Delimiter">}</span>
<span id="L140" class="LineNr">140 </span>
<span id="L141" class="LineNr">141 </span><span class="PreProc">fn</span> <span class="muTest"><a href='412render-float-decimal.mu.html#L141'>test-write-float-decimal-approximate-not-a-number</a></span> <span class="Delimiter">{</span>
<span id="L142" class="LineNr">142 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L143" class="LineNr">143 </span>  <span class="PreProc">var</span> s/<span class="muRegEcx">ecx</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L144" class="LineNr">144 </span>  <span class="PreProc">var</span> n: int
<span id="L145" class="LineNr">145 </span>  copy-to n, <span class="Constant">0xffffffff</span>  <span class="muComment"># exponent must be all 1's, and mantissa must be non-zero</span>
<span id="L146" class="LineNr">146 </span>  <span class="PreProc">var</span> nan/<span class="Constant">xmm0</span>: float <span class="Special">&lt;-</span> reinterpret n
<span id="L147" class="LineNr">147 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, nan, <span class="Constant">3</span>
<span id="L148" class="LineNr">148 </span>  <a href='109stream-equal.subx.html#L194'>check-stream-equal</a> s, <span class="Constant">&quot;NaN&quot;</span>, <span class="Constant">&quot;F - test-write-float-decimal-approximate-not-a-number&quot;</span>
<span id="L149" class="LineNr">149 </span><span class="Delimiter">}</span>
<span id="L150" class="LineNr">150 </span>
<span id="L151" class="LineNr">151 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L151'>render-float-decimal</a></span> <a href='500fake-screen.mu.html#L14'>screen</a>: (addr <a href='500fake-screen.mu.html#L14'>screen</a>), in: float, precision: int, x: int, y: int, color: int, background-color: int<span class="PreProc"> -&gt; </span>_/<span class="muRegEax">eax</span>: int <span class="Delimiter">{</span>
<span id="L152" class="LineNr">152 </span>  <span class="PreProc">var</span> s-storage: (stream byte <span class="Constant">0x10</span>)
<span id="L153" class="LineNr">153 </span>  <span class="PreProc">var</span> s/<span class="muRegEsi">esi</span>: (addr stream byte) <span class="Special">&lt;-</span> address s-storage
<span id="L154" class="LineNr">154 </span>  <a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a> s, in, precision
<span id="L155" class="LineNr">155 </span>  <span class="PreProc">var</span> width/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L156" class="LineNr">156 </span>  <span class="PreProc">var</span> height/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L157" class="LineNr">157 </span>  width, height <span class="Special">&lt;-</span> <a href='500fake-screen.mu.html#L86'>screen-size</a> <a href='500fake-screen.mu.html#L14'>screen</a>
<span id="L158" class="LineNr">158 </span>  <span class="PreProc">var</span> result/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> <a href='501draw-text.mu.html#L111'>draw-stream-rightward</a> <a href='500fake-screen.mu.html#L14'>screen</a>, s, x, width, y, color, background-color
<span id="L159" class="LineNr">159 </span>  <span class="PreProc">return</span> result
<span id="L160" class="LineNr">160 </span><span class="Delimiter">}</span>
<span id="L161" class="LineNr">161 </span>
<span id="L162" class="LineNr">162 </span><span class="muComment"># 'precision' controls the maximum width past which we resort to scientific notation</span>
<span id="L163" class="LineNr">163 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L163'>write-float-decimal-approximate</a></span> out: (addr stream byte), in: float, precision: int <span class="Delimiter">{</span>
<span id="L164" class="LineNr">164 </span>  <span class="muComment"># - special names</span>
<span id="L165" class="LineNr">165 </span>  <span class="PreProc">var</span> bits/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> reinterpret in
<span id="L166" class="LineNr">166 </span>  compare bits, <span class="Constant">0</span>
<span id="L167" class="LineNr">167 </span>  <span class="Delimiter">{</span>
<span id="L168" class="LineNr">168 </span>    <span class="PreProc">break-if-!=</span>
<span id="L169" class="LineNr">169 </span>    <a href='108write.subx.html#L11'>write</a> out, <span class="Constant">&quot;0&quot;</span>
<span id="L170" class="LineNr">170 </span>    <span class="PreProc">return</span>
<span id="L171" class="LineNr">171 </span>  <span class="Delimiter">}</span>
<span id="L172" class="LineNr">172 </span>  compare bits, <span class="Constant">0x80000000</span>
<span id="L173" class="LineNr">173 </span>  <span class="Delimiter">{</span>
<span id="L174" class="LineNr">174 </span>    <span class="PreProc">break-if-!=</span>
<span id="L175" class="LineNr">175 </span>    <a href='108write.subx.html#L11'>write</a> out, <span class="Constant">&quot;-0&quot;</span>
<span id="L176" class="LineNr">176 </span>    <span class="PreProc">return</span>
<span id="L177" class="LineNr">177 </span>  <span class="Delimiter">}</span>
<span id="L178" class="LineNr">178 </span>  compare bits, <span class="Constant">0x7f800000</span>
<span id="L179" class="LineNr">179 </span>  <span class="Delimiter">{</span>
<span id="L180" class="LineNr">180 </span>    <span class="PreProc">break-if-!=</span>
<span id="L181" class="LineNr">181 </span>    <a href='108write.subx.html#L11'>write</a> out, <span class="Constant">&quot;Inf&quot;</span>
<span id="L182" class="LineNr">182 </span>    <span class="PreProc">return</span>
<span id="L183" class="LineNr">183 </span>  <span class="Delimiter">}</span>
<span id="L184" class="LineNr">184 </span>  compare bits, <span class="Constant">0xff800000</span>
<span id="L185" class="LineNr">185 </span>  <span class="Delimiter">{</span>
<span id="L186" class="LineNr">186 </span>    <span class="PreProc">break-if-!=</span>
<span id="L187" class="LineNr">187 </span>    <a href='108write.subx.html#L11'>write</a> out, <span class="Constant">&quot;-Inf&quot;</span>
<span id="L188" class="LineNr">188 </span>    <span class="PreProc">return</span>
<span id="L189" class="LineNr">189 </span>  <span class="Delimiter">}</span>
<span id="L190" class="LineNr">190 </span>  <span class="PreProc">var</span> exponent/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy bits
<span id="L191" class="LineNr">191 </span>  exponent <span class="Special">&lt;-</span> shift-right <span class="Constant">0x17</span>  <span class="muComment"># 23 bits of mantissa</span>
<span id="L192" class="LineNr">192 </span>  exponent <span class="Special">&lt;-</span> and <span class="Constant">0xff</span>
<span id="L193" class="LineNr">193 </span>  exponent <span class="Special">&lt;-</span> subtract <span class="Constant">0x7f</span>
<span id="L194" class="LineNr">194 </span>  compare exponent, <span class="Constant">0x80</span>
<span id="L195" class="LineNr">195 </span>  <span class="Delimiter">{</span>
<span id="L196" class="LineNr">196 </span>    <span class="PreProc">break-if-!=</span>
<span id="L197" class="LineNr">197 </span>    <a href='108write.subx.html#L11'>write</a> out, <span class="Constant">&quot;NaN&quot;</span>
<span id="L198" class="LineNr">198 </span>    <span class="PreProc">return</span>
<span id="L199" class="LineNr">199 </span>  <span class="Delimiter">}</span>
<span id="L200" class="LineNr">200 </span>  <span class="muComment"># - regular numbers</span>
<span id="L201" class="LineNr">201 </span>  <span class="PreProc">var</span> sign/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy bits
<span id="L202" class="LineNr">202 </span>  sign <span class="Special">&lt;-</span> shift-right <span class="Constant">0x1f</span>
<span id="L203" class="LineNr">203 </span>  <span class="Delimiter">{</span>
<span id="L204" class="LineNr">204 </span>    compare sign, <span class="Constant">1</span>
<span id="L205" class="LineNr">205 </span>    <span class="PreProc">break-if-!=</span>
<span id="L206" class="LineNr">206 </span>    <a href='115write-byte.subx.html#L12'>append-byte</a> out, <span class="Constant">0x2d</span>/minus
<span id="L207" class="LineNr">207 </span>  <span class="Delimiter">}</span>
<span id="L208" class="LineNr">208 </span>
<span id="L209" class="LineNr">209 </span>  <span class="muComment"># v = 1.mantissa (in base 2) &lt;&lt; 0x17</span>
<span id="L210" class="LineNr">210 </span>  <span class="PreProc">var</span> v/<span class="muRegEbx">ebx</span>: int <span class="Special">&lt;-</span> copy bits
<span id="L211" class="LineNr">211 </span>  v <span class="Special">&lt;-</span> and <span class="Constant">0x7fffff</span>
<span id="L212" class="LineNr">212 </span>  v <span class="Special">&lt;-</span> or <span class="Constant">0x00800000</span>  <span class="muComment"># insert implicit 1</span>
<span id="L213" class="LineNr">213 </span>  <span class="muComment"># e = exponent - 0x17</span>
<span id="L214" class="LineNr">214 </span>  <span class="PreProc">var</span> e/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy exponent
<span id="L215" class="LineNr">215 </span>  e <span class="Special">&lt;-</span> subtract <span class="Constant">0x17</span>  <span class="muComment"># move decimal place from before mantissa to after</span>
<span id="L216" class="LineNr">216 </span>
<span id="L217" class="LineNr">217 </span>  <span class="muComment"># initialize buffer with decimal representation of v</span>
<span id="L218" class="LineNr">218 </span>  <span class="muComment"># unlike <a href="https://research.swtch.com/ftoa">https://research.swtch.com/ftoa</a>, no ascii here</span>
<span id="L219" class="LineNr">219 </span>  <span class="PreProc">var</span> buf-storage: (array byte <span class="Constant">0x7f</span>)
<span id="L220" class="LineNr">220 </span>  <span class="PreProc">var</span> buf/<span class="muRegEdi">edi</span>: (addr array byte) <span class="Special">&lt;-</span> address buf-storage
<span id="L221" class="LineNr">221 </span>  <span class="PreProc">var</span> n/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> <a href='412render-float-decimal.mu.html#L251'>decimal-digits</a> v, buf
<span id="L222" class="LineNr">222 </span>  <span class="muComment"># I suspect we can do without reversing, but we'll follow <a href="https://research.swtch.com/ftoa">https://research.swtch.com/ftoa</a></span>
<span id="L223" class="LineNr">223 </span>  <span class="muComment"># closely for now.</span>
<span id="L224" class="LineNr">224 </span>  <a href='412render-float-decimal.mu.html#L268'>reverse-digits</a> buf, n
<span id="L225" class="LineNr">225 </span>
<span id="L226" class="LineNr">226 </span>  <span class="muComment"># loop if e &gt; 0</span>
<span id="L227" class="LineNr">227 </span>  <span class="Delimiter">{</span>
<span id="L228" class="LineNr">228 </span>    compare e, <span class="Constant">0</span>
<span id="L229" class="LineNr">229 </span>    <span class="PreProc">break-if-&lt;=</span>
<span id="L230" class="LineNr">230 </span>    n <span class="Special">&lt;-</span> <a href='412render-float-decimal.mu.html#L290'>double-array-of-decimal-digits</a> buf, n
<span id="L231" class="LineNr">231 </span>    e <span class="Special">&lt;-</span> decrement
<span id="L232" class="LineNr">232 </span>    <span class="PreProc">loop</span>
<span id="L233" class="LineNr">233 </span>  <span class="Delimiter">}</span>
<span id="L234" class="LineNr">234 </span>
<span id="L235" class="LineNr">235 </span>  <span class="PreProc">var</span> dp/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy n
<span id="L236" class="LineNr">236 </span>
<span id="L237" class="LineNr">237 </span>  <span class="muComment"># loop if e &lt; 0</span>
<span id="L238" class="LineNr">238 </span>  <span class="Delimiter">{</span>
<span id="L239" class="LineNr">239 </span>    compare e, <span class="Constant">0</span>
<span id="L240" class="LineNr">240 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L241" class="LineNr">241 </span>    n, dp <span class="Special">&lt;-</span> <a href='412render-float-decimal.mu.html#L341'>halve-array-of-decimal-digits</a> buf, n, dp
<span id="L242" class="LineNr">242 </span>    e <span class="Special">&lt;-</span> increment
<span id="L243" class="LineNr">243 </span>    <span class="PreProc">loop</span>
<span id="L244" class="LineNr">244 </span>  <span class="Delimiter">}</span>
<span id="L245" class="LineNr">245 </span>
<span id="L246" class="LineNr">246 </span>  <a href='412render-float-decimal.mu.html#L415'>_write-float-array-of-decimal-digits</a> out, buf, n, dp, precision
<span id="L247" class="LineNr">247 </span><span class="Delimiter">}</span>
<span id="L248" class="LineNr">248 </span>
<span id="L249" class="LineNr">249 </span><span class="muComment"># store the decimal digits of 'n' into 'buf', units first</span>
<span id="L250" class="LineNr">250 </span><span class="muComment"># n must be positive</span>
<span id="L251" class="LineNr">251 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L251'>decimal-digits</a></span> n: int, _buf: (addr array byte)<span class="PreProc"> -&gt; </span>_/<span class="muRegEax">eax</span>: int <span class="Delimiter">{</span>
<span id="L252" class="LineNr">252 </span>  <span class="PreProc">var</span> buf/<span class="muRegEdi">edi</span>: (addr array byte) <span class="Special">&lt;-</span> copy _buf
<span id="L253" class="LineNr">253 </span>  <span class="PreProc">var</span> i/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L254" class="LineNr">254 </span>  <span class="PreProc">var</span> curr/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy n
<span id="L255" class="LineNr">255 </span>  <span class="PreProc">var</span> curr-byte/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L256" class="LineNr">256 </span>  <span class="Delimiter">{</span>
<span id="L257" class="LineNr">257 </span>    compare curr, <span class="Constant">0</span>
<span id="L258" class="LineNr">258 </span>    <span class="PreProc">break-if-=</span>
<span id="L259" class="LineNr">259 </span>    curr, curr-byte <span class="Special">&lt;-</span> <a href='314divide.subx.html#L3'>integer-divide</a> curr, <span class="Constant">0xa</span>
<span id="L260" class="LineNr">260 </span>    <span class="PreProc">var</span> dest/<span class="muRegEbx">ebx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, i
<span id="L261" class="LineNr">261 </span>    copy-byte-to *dest, curr-byte
<span id="L262" class="LineNr">262 </span>    i <span class="Special">&lt;-</span> increment
<span id="L263" class="LineNr">263 </span>    <span class="PreProc">loop</span>
<span id="L264" class="LineNr">264 </span>  <span class="Delimiter">}</span>
<span id="L265" class="LineNr">265 </span>  <span class="PreProc">return</span> i
<span id="L266" class="LineNr">266 </span><span class="Delimiter">}</span>
<span id="L267" class="LineNr">267 </span>
<span id="L268" class="LineNr">268 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L268'>reverse-digits</a></span> _buf: (addr array byte), n: int <span class="Delimiter">{</span>
<span id="L269" class="LineNr">269 </span>  <span class="PreProc">var</span> buf/<span class="muRegEsi">esi</span>: (addr array byte) <span class="Special">&lt;-</span> copy _buf
<span id="L270" class="LineNr">270 </span>  <span class="PreProc">var</span> left/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L271" class="LineNr">271 </span>  <span class="PreProc">var</span> right/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy n
<span id="L272" class="LineNr">272 </span>  right <span class="Special">&lt;-</span> decrement
<span id="L273" class="LineNr">273 </span>  <span class="Delimiter">{</span>
<span id="L274" class="LineNr">274 </span>    compare left, right
<span id="L275" class="LineNr">275 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L276" class="LineNr">276 </span>    <span class="Delimiter">{</span>
<span id="L277" class="LineNr">277 </span>      <span class="PreProc">var</span> l-a/<span class="muRegEcx">ecx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, left
<span id="L278" class="LineNr">278 </span>      <span class="PreProc">var</span> r-a/<span class="muRegEdx">edx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, right
<span id="L279" class="LineNr">279 </span>      <span class="PreProc">var</span> l/<span class="muRegEbx">ebx</span>: byte <span class="Special">&lt;-</span> copy-byte *l-a
<span id="L280" class="LineNr">280 </span>      <span class="PreProc">var</span> r/<span class="muRegEax">eax</span>: byte <span class="Special">&lt;-</span> copy-byte *r-a
<span id="L281" class="LineNr">281 </span>      copy-byte-to *l-a, r
<span id="L282" class="LineNr">282 </span>      copy-byte-to *r-a, l
<span id="L283" class="LineNr">283 </span>    <span class="Delimiter">}</span>
<span id="L284" class="LineNr">284 </span>    left <span class="Special">&lt;-</span> increment
<span id="L285" class="LineNr">285 </span>    right <span class="Special">&lt;-</span> decrement
<span id="L286" class="LineNr">286 </span>    <span class="PreProc">loop</span>
<span id="L287" class="LineNr">287 </span>  <span class="Delimiter">}</span>
<span id="L288" class="LineNr">288 </span><span class="Delimiter">}</span>
<span id="L289" class="LineNr">289 </span>
<span id="L290" class="LineNr">290 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L290'>double-array-of-decimal-digits</a></span> _buf: (addr array byte), _n: int<span class="PreProc"> -&gt; </span>_/<span class="muRegEax">eax</span>: int <span class="Delimiter">{</span>
<span id="L291" class="LineNr">291 </span>  <span class="PreProc">var</span> buf/<span class="muRegEdi">edi</span>: (addr array byte) <span class="Special">&lt;-</span> copy _buf
<span id="L292" class="LineNr">292 </span>  <span class="muComment"># initialize delta</span>
<span id="L293" class="LineNr">293 </span>  <span class="PreProc">var</span> delta/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L294" class="LineNr">294 </span>  <span class="Delimiter">{</span>
<span id="L295" class="LineNr">295 </span>    <span class="PreProc">var</span> curr/<span class="muRegEbx">ebx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, <span class="Constant">0</span>
<span id="L296" class="LineNr">296 </span>    <span class="PreProc">var</span> tmp/<span class="muRegEax">eax</span>: byte <span class="Special">&lt;-</span> copy-byte *curr
<span id="L297" class="LineNr">297 </span>    compare tmp, <span class="Constant">5</span>
<span id="L298" class="LineNr">298 </span>    <span class="PreProc">break-if-&lt;</span>
<span id="L299" class="LineNr">299 </span>    delta <span class="Special">&lt;-</span> copy <span class="Constant">1</span>
<span id="L300" class="LineNr">300 </span>  <span class="Delimiter">}</span>
<span id="L301" class="LineNr">301 </span>  <span class="muComment"># loop</span>
<span id="L302" class="LineNr">302 </span>  <span class="PreProc">var</span> x/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L303" class="LineNr">303 </span>  <span class="PreProc">var</span> i/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy _n
<span id="L304" class="LineNr">304 </span>  i <span class="Special">&lt;-</span> decrement
<span id="L305" class="LineNr">305 </span>  <span class="Delimiter">{</span>
<span id="L306" class="LineNr">306 </span>    compare i, <span class="Constant">0</span>
<span id="L307" class="LineNr">307 </span>    <span class="PreProc">break-if-&lt;=</span>
<span id="L308" class="LineNr">308 </span>    <span class="muComment"># x += 2*buf[i]</span>
<span id="L309" class="LineNr">309 </span>    <span class="Delimiter">{</span>
<span id="L310" class="LineNr">310 </span>      <span class="PreProc">var</span> tmp/<span class="muRegEcx">ecx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, i
<span id="L311" class="LineNr">311 </span>      <span class="PreProc">var</span> tmp2/<span class="muRegEcx">ecx</span>: byte <span class="Special">&lt;-</span> copy-byte *tmp
<span id="L312" class="LineNr">312 </span>      x <span class="Special">&lt;-</span> add tmp2
<span id="L313" class="LineNr">313 </span>      x <span class="Special">&lt;-</span> add tmp2
<span id="L314" class="LineNr">314 </span>    <span class="Delimiter">}</span>
<span id="L315" class="LineNr">315 </span>    <span class="muComment"># x, buf[i+delta] = x/10, x%10</span>
<span id="L316" class="LineNr">316 </span>    <span class="Delimiter">{</span>
<span id="L317" class="LineNr">317 </span>      <span class="PreProc">var</span> dest-index/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy i
<span id="L318" class="LineNr">318 </span>      dest-index <span class="Special">&lt;-</span> add delta
<span id="L319" class="LineNr">319 </span>      <span class="PreProc">var</span> dest/<span class="muRegEdi">edi</span>: (addr byte) <span class="Special">&lt;-</span> index buf, dest-index
<span id="L320" class="LineNr">320 </span>      <span class="PreProc">var</span> next-digit/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L321" class="LineNr">321 </span>      x, next-digit <span class="Special">&lt;-</span> <a href='314divide.subx.html#L3'>integer-divide</a> x, <span class="Constant">0xa</span>
<span id="L322" class="LineNr">322 </span>      copy-byte-to *dest, next-digit
<span id="L323" class="LineNr">323 </span>    <span class="Delimiter">}</span>
<span id="L324" class="LineNr">324 </span>    <span class="muComment">#</span>
<span id="L325" class="LineNr">325 </span>    i <span class="Special">&lt;-</span> decrement
<span id="L326" class="LineNr">326 </span>    <span class="PreProc">loop</span>
<span id="L327" class="LineNr">327 </span>  <span class="Delimiter">}</span>
<span id="L328" class="LineNr">328 </span>  <span class="muComment"># final patch-up</span>
<span id="L329" class="LineNr">329 </span>  <span class="PreProc">var</span> n/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy _n
<span id="L330" class="LineNr">330 </span>  compare delta, <span class="Constant">1</span>
<span id="L331" class="LineNr">331 </span>  <span class="Delimiter">{</span>
<span id="L332" class="LineNr">332 </span>    <span class="PreProc">break-if-!=</span>
<span id="L333" class="LineNr">333 </span>    <span class="PreProc">var</span> curr/<span class="muRegEbx">ebx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, <span class="Constant">0</span>
<span id="L334" class="LineNr">334 </span>    <span class="PreProc">var</span> one/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">1</span>
<span id="L335" class="LineNr">335 </span>    copy-byte-to *curr, one
<span id="L336" class="LineNr">336 </span>    n <span class="Special">&lt;-</span> increment
<span id="L337" class="LineNr">337 </span>  <span class="Delimiter">}</span>
<span id="L338" class="LineNr">338 </span>  <span class="PreProc">return</span> n
<span id="L339" class="LineNr">339 </span><span class="Delimiter">}</span>
<span id="L340" class="LineNr">340 </span>
<span id="L341" class="LineNr">341 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L341'>halve-array-of-decimal-digits</a></span> _buf: (addr array byte), _n: int, _dp: int<span class="PreProc"> -&gt; </span>_/<span class="muRegEax">eax</span>: int, _/<span class="muRegEdx">edx</span>: int <span class="Delimiter">{</span>
<span id="L342" class="LineNr">342 </span>  <span class="PreProc">var</span> buf/<span class="muRegEdi">edi</span>: (addr array byte) <span class="Special">&lt;-</span> copy _buf
<span id="L343" class="LineNr">343 </span>  <span class="PreProc">var</span> n/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy _n
<span id="L344" class="LineNr">344 </span>  <span class="PreProc">var</span> dp/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy _dp
<span id="L345" class="LineNr">345 </span>  <span class="muComment"># initialize one side</span>
<span id="L346" class="LineNr">346 </span>  <span class="Delimiter">{</span>
<span id="L347" class="LineNr">347 </span>    <span class="muComment"># if buf[n-1]%2 == 0, break</span>
<span id="L348" class="LineNr">348 </span>    <span class="PreProc">var</span> right-index/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy n
<span id="L349" class="LineNr">349 </span>    right-index <span class="Special">&lt;-</span> decrement
<span id="L350" class="LineNr">350 </span>    <span class="PreProc">var</span> right-a/<span class="muRegEcx">ecx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, right-index
<span id="L351" class="LineNr">351 </span>    <span class="PreProc">var</span> right/<span class="muRegEcx">ecx</span>: byte <span class="Special">&lt;-</span> copy-byte *right-a
<span id="L352" class="LineNr">352 </span>    <span class="PreProc">var</span> right-int/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy right
<span id="L353" class="LineNr">353 </span>    <span class="PreProc">var</span> remainder/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L354" class="LineNr">354 </span>    <span class="Delimiter">{</span>
<span id="L355" class="LineNr">355 </span>      <span class="PreProc">var</span> dummy/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L356" class="LineNr">356 </span>      dummy, remainder <span class="Special">&lt;-</span> <a href='314divide.subx.html#L3'>integer-divide</a> right-int, <span class="Constant">2</span>
<span id="L357" class="LineNr">357 </span>    <span class="Delimiter">}</span>
<span id="L358" class="LineNr">358 </span>    compare remainder, <span class="Constant">0</span>
<span id="L359" class="LineNr">359 </span>    <span class="PreProc">break-if-=</span>
<span id="L360" class="LineNr">360 </span>    <span class="muComment"># buf[n] = 0</span>
<span id="L361" class="LineNr">361 </span>    <span class="PreProc">var</span> next-a/<span class="muRegEcx">ecx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, n
<span id="L362" class="LineNr">362 </span>    <span class="PreProc">var</span> zero/<span class="muRegEdx">edx</span>: byte <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L363" class="LineNr">363 </span>    copy-byte-to *next-a, zero
<span id="L364" class="LineNr">364 </span>    <span class="muComment"># n++</span>
<span id="L365" class="LineNr">365 </span>    n <span class="Special">&lt;-</span> increment
<span id="L366" class="LineNr">366 </span>  <span class="Delimiter">}</span>
<span id="L367" class="LineNr">367 </span>  <span class="muComment"># initialize the other</span>
<span id="L368" class="LineNr">368 </span>  <span class="PreProc">var</span> delta/<span class="muRegEbx">ebx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L369" class="LineNr">369 </span>  <span class="PreProc">var</span> x/<span class="muRegEsi">esi</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L370" class="LineNr">370 </span>  <span class="Delimiter">{</span>
<span id="L371" class="LineNr">371 </span>    <span class="muComment"># if buf[0] &gt;= 2, break</span>
<span id="L372" class="LineNr">372 </span>    <span class="PreProc">var</span> left/<span class="muRegEcx">ecx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, <span class="Constant">0</span>
<span id="L373" class="LineNr">373 </span>    <span class="PreProc">var</span> src/<span class="muRegEcx">ecx</span>: byte <span class="Special">&lt;-</span> copy-byte *left
<span id="L374" class="LineNr">374 </span>    compare src, <span class="Constant">2</span>
<span id="L375" class="LineNr">375 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L376" class="LineNr">376 </span>    <span class="muComment"># delta, x = 1, buf[0]</span>
<span id="L377" class="LineNr">377 </span>    delta <span class="Special">&lt;-</span> copy <span class="Constant">1</span>
<span id="L378" class="LineNr">378 </span>    x <span class="Special">&lt;-</span> copy src
<span id="L379" class="LineNr">379 </span>    <span class="muComment"># n--</span>
<span id="L380" class="LineNr">380 </span>    n <span class="Special">&lt;-</span> decrement
<span id="L381" class="LineNr">381 </span>    <span class="muComment"># dp--</span>
<span id="L382" class="LineNr">382 </span>    dp <span class="Special">&lt;-</span> decrement
<span id="L383" class="LineNr">383 </span>  <span class="Delimiter">}</span>
<span id="L384" class="LineNr">384 </span>  <span class="muComment"># loop</span>
<span id="L385" class="LineNr">385 </span>  <span class="PreProc">var</span> i/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L386" class="LineNr">386 </span>  <span class="Delimiter">{</span>
<span id="L387" class="LineNr">387 </span>    compare i, n
<span id="L388" class="LineNr">388 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L389" class="LineNr">389 </span>    <span class="muComment"># x = x*10 + buf[i+delta]</span>
<span id="L390" class="LineNr">390 </span>    <span class="Delimiter">{</span>
<span id="L391" class="LineNr">391 </span>      <span class="PreProc">var</span> ten/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0xa</span>
<span id="L392" class="LineNr">392 </span>      x <span class="Special">&lt;-</span> multiply ten
<span id="L393" class="LineNr">393 </span>      <span class="PreProc">var</span> src-index/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy i
<span id="L394" class="LineNr">394 </span>      src-index <span class="Special">&lt;-</span> add delta
<span id="L395" class="LineNr">395 </span>      <span class="PreProc">var</span> src-a/<span class="muRegEdx">edx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, src-index
<span id="L396" class="LineNr">396 </span>      <span class="PreProc">var</span> src/<span class="muRegEdx">edx</span>: byte <span class="Special">&lt;-</span> copy-byte *src-a
<span id="L397" class="LineNr">397 </span>      x <span class="Special">&lt;-</span> add src
<span id="L398" class="LineNr">398 </span>    <span class="Delimiter">}</span>
<span id="L399" class="LineNr">399 </span>    <span class="muComment"># buf[i], x = x/2, x%2</span>
<span id="L400" class="LineNr">400 </span>    <span class="Delimiter">{</span>
<span id="L401" class="LineNr">401 </span>      <span class="PreProc">var</span> quotient/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L402" class="LineNr">402 </span>      <span class="PreProc">var</span> remainder/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L403" class="LineNr">403 </span>      quotient, remainder <span class="Special">&lt;-</span> <a href='314divide.subx.html#L3'>integer-divide</a> x, <span class="Constant">2</span>
<span id="L404" class="LineNr">404 </span>      x <span class="Special">&lt;-</span> copy remainder
<span id="L405" class="LineNr">405 </span>      <span class="PreProc">var</span> dest/<span class="muRegEdx">edx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, i
<span id="L406" class="LineNr">406 </span>      copy-byte-to *dest, quotient
<span id="L407" class="LineNr">407 </span>    <span class="Delimiter">}</span>
<span id="L408" class="LineNr">408 </span>    <span class="muComment">#</span>
<span id="L409" class="LineNr">409 </span>    i <span class="Special">&lt;-</span> increment
<span id="L410" class="LineNr">410 </span>    <span class="PreProc">loop</span>
<span id="L411" class="LineNr">411 </span>  <span class="Delimiter">}</span>
<span id="L412" class="LineNr">412 </span>  <span class="PreProc">return</span> n, dp
<span id="L413" class="LineNr">413 </span><span class="Delimiter">}</span>
<span id="L414" class="LineNr">414 </span>
<span id="L415" class="LineNr">415 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L415'>_write-float-array-of-decimal-digits</a></span> out: (addr stream byte), _buf: (addr array byte), n: int, dp: int, precision: int <span class="Delimiter">{</span>
<span id="L416" class="LineNr">416 </span>  <span class="PreProc">var</span> buf/<span class="muRegEdi">edi</span>: (addr array byte) <span class="Special">&lt;-</span> copy _buf
<span id="L417" class="LineNr">417 </span>  <span class="Delimiter">{</span>
<span id="L418" class="LineNr">418 </span>    compare dp, <span class="Constant">0</span>
<span id="L419" class="LineNr">419 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L420" class="LineNr">420 </span>    <a href='412render-float-decimal.mu.html#L464'>_write-float-array-of-decimal-digits-in-scientific-notation</a> out, buf, n, dp, precision
<span id="L421" class="LineNr">421 </span>    <span class="PreProc">return</span>
<span id="L422" class="LineNr">422 </span>  <span class="Delimiter">}</span>
<span id="L423" class="LineNr">423 </span>  <span class="Delimiter">{</span>
<span id="L424" class="LineNr">424 </span>    <span class="PreProc">var</span> dp2/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy dp
<span id="L425" class="LineNr">425 </span>    compare dp2, precision
<span id="L426" class="LineNr">426 </span>    <span class="PreProc">break-if-&lt;=</span>
<span id="L427" class="LineNr">427 </span>    <a href='412render-float-decimal.mu.html#L464'>_write-float-array-of-decimal-digits-in-scientific-notation</a> out, buf, n, dp, precision
<span id="L428" class="LineNr">428 </span>    <span class="PreProc">return</span>
<span id="L429" class="LineNr">429 </span>  <span class="Delimiter">}</span>
<span id="L430" class="LineNr">430 </span>  <span class="Delimiter">{</span>
<span id="L431" class="LineNr">431 </span>    compare dp, <span class="Constant">0</span>
<span id="L432" class="LineNr">432 </span>    <span class="PreProc">break-if-!=</span>
<span id="L433" class="LineNr">433 </span>    <a href='115write-byte.subx.html#L12'>append-byte</a> out, <span class="Constant">0x30</span>/<span class="Constant">0</span>
<span id="L434" class="LineNr">434 </span>  <span class="Delimiter">}</span>
<span id="L435" class="LineNr">435 </span>  <span class="PreProc">var</span> i/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L436" class="LineNr">436 </span>  <span class="muComment"># bounds = min(n, dp+3)</span>
<span id="L437" class="LineNr">437 </span>  <span class="PreProc">var</span> limit/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy dp
<span id="L438" class="LineNr">438 </span>  limit <span class="Special">&lt;-</span> add <span class="Constant">3</span>
<span id="L439" class="LineNr">439 </span>  <span class="Delimiter">{</span>
<span id="L440" class="LineNr">440 </span>    compare limit, n
<span id="L441" class="LineNr">441 </span>    <span class="PreProc">break-if-&lt;=</span>
<span id="L442" class="LineNr">442 </span>    limit <span class="Special">&lt;-</span> copy n
<span id="L443" class="LineNr">443 </span>  <span class="Delimiter">}</span>
<span id="L444" class="LineNr">444 </span>  <span class="Delimiter">{</span>
<span id="L445" class="LineNr">445 </span>    compare i, limit
<span id="L446" class="LineNr">446 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L447" class="LineNr">447 </span>    <span class="muComment"># print '.' if necessary</span>
<span id="L448" class="LineNr">448 </span>    compare i, dp
<span id="L449" class="LineNr">449 </span>    <span class="Delimiter">{</span>
<span id="L450" class="LineNr">450 </span>      <span class="PreProc">break-if-!=</span>
<span id="L451" class="LineNr">451 </span>      <a href='115write-byte.subx.html#L12'>append-byte</a> out, <span class="Constant">0x2e</span>/decimal-point
<span id="L452" class="LineNr">452 </span>    <span class="Delimiter">}</span>
<span id="L453" class="LineNr">453 </span>    <span class="PreProc">var</span> curr-a/<span class="muRegEcx">ecx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, i
<span id="L454" class="LineNr">454 </span>    <span class="PreProc">var</span> curr/<span class="muRegEcx">ecx</span>: byte <span class="Special">&lt;-</span> copy-byte *curr-a
<span id="L455" class="LineNr">455 </span>    <span class="PreProc">var</span> curr-int/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy curr
<span id="L456" class="LineNr">456 </span>    curr-int <span class="Special">&lt;-</span> add <span class="Constant">0x30</span>/<span class="Constant">0</span>
<span id="L457" class="LineNr">457 </span>    <a href='115write-byte.subx.html#L12'>append-byte</a> out, curr-int
<span id="L458" class="LineNr">458 </span>    <span class="muComment">#</span>
<span id="L459" class="LineNr">459 </span>    i <span class="Special">&lt;-</span> increment
<span id="L460" class="LineNr">460 </span>    <span class="PreProc">loop</span>
<span id="L461" class="LineNr">461 </span>  <span class="Delimiter">}</span>
<span id="L462" class="LineNr">462 </span><span class="Delimiter">}</span>
<span id="L463" class="LineNr">463 </span>
<span id="L464" class="LineNr">464 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L464'>_write-float-array-of-decimal-digits-in-scientific-notation</a></span> out: (addr stream byte), _buf: (addr array byte), n: int, dp: int, precision: int <span class="Delimiter">{</span>
<span id="L465" class="LineNr">465 </span>  <span class="PreProc">var</span> buf/<span class="muRegEdi">edi</span>: (addr array byte) <span class="Special">&lt;-</span> copy _buf
<span id="L466" class="LineNr">466 </span>  <span class="PreProc">var</span> i/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy <span class="Constant">0</span>
<span id="L467" class="LineNr">467 </span>  <span class="Delimiter">{</span>
<span id="L468" class="LineNr">468 </span>    compare i, n
<span id="L469" class="LineNr">469 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L470" class="LineNr">470 </span>    compare i, precision
<span id="L471" class="LineNr">471 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L472" class="LineNr">472 </span>    compare i, <span class="Constant">1</span>
<span id="L473" class="LineNr">473 </span>    <span class="Delimiter">{</span>
<span id="L474" class="LineNr">474 </span>      <span class="PreProc">break-if-!=</span>
<span id="L475" class="LineNr">475 </span>      <a href='115write-byte.subx.html#L12'>append-byte</a> out, <span class="Constant">0x2e</span>/decimal-point
<span id="L476" class="LineNr">476 </span>    <span class="Delimiter">}</span>
<span id="L477" class="LineNr">477 </span>    <span class="PreProc">var</span> curr-a/<span class="muRegEcx">ecx</span>: (addr byte) <span class="Special">&lt;-</span> index buf, i
<span id="L478" class="LineNr">478 </span>    <span class="PreProc">var</span> curr/<span class="muRegEcx">ecx</span>: byte <span class="Special">&lt;-</span> copy-byte *curr-a
<span id="L479" class="LineNr">479 </span>    <span class="PreProc">var</span> curr-int/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy curr
<span id="L480" class="LineNr">480 </span>    curr-int <span class="Special">&lt;-</span> add <span class="Constant">0x30</span>/<span class="Constant">0</span>
<span id="L481" class="LineNr">481 </span>    <a href='115write-byte.subx.html#L12'>append-byte</a> out, curr-int
<span id="L482" class="LineNr">482 </span>    <span class="muComment">#</span>
<span id="L483" class="LineNr">483 </span>    i <span class="Special">&lt;-</span> increment
<span id="L484" class="LineNr">484 </span>    <span class="PreProc">loop</span>
<span id="L485" class="LineNr">485 </span>  <span class="Delimiter">}</span>
<span id="L486" class="LineNr">486 </span>  <a href='115write-byte.subx.html#L12'>append-byte</a> out, <span class="Constant">0x65</span>/e
<span id="L487" class="LineNr">487 </span>  decrement dp
<span id="L488" class="LineNr">488 </span>  <a href='126write-int-decimal.subx.html#L8'>write-int32-decimal</a> out, dp
<span id="L489" class="LineNr">489 </span><span class="Delimiter">}</span>
<span id="L490" class="LineNr">490 </span>
<span id="L491" class="LineNr">491 </span><span class="muComment"># follows the structure of write-float-decimal-approximate</span>
<span id="L492" class="LineNr">492 </span><span class="muComment"># 'precision' controls the maximum width past which we resort to scientific notation</span>
<span id="L493" class="LineNr">493 </span><span class="PreProc">fn</span> <span class="muFunction"><a href='412render-float-decimal.mu.html#L493'>float-size</a></span> in: float, precision: int<span class="PreProc"> -&gt; </span>_/<span class="muRegEax">eax</span>: int <span class="Delimiter">{</span>
<span id="L494" class="LineNr">494 </span>  <span class="muComment"># - special names</span>
<span id="L495" class="LineNr">495 </span>  <span class="PreProc">var</span> bits/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> reinterpret in
<span id="L496" class="LineNr">496 </span>  compare bits, <span class="Constant">0</span>
<span id="L497" class="LineNr">497 </span>  <span class="Delimiter">{</span>
<span id="L498" class="LineNr">498 </span>    <span class="PreProc">break-if-!=</span>
<span id="L499" class="LineNr">499 </span>    <span class="PreProc">return</span> <span class="Constant">1</span>  <span class="muComment"># for &quot;0&quot;</span>
<span id="L500" class="LineNr">500 </span>  <span class="Delimiter">}</span>
<span id="L501" class="LineNr">501 </span>  compare bits, <span class="Constant">0x80000000</span>
<span id="L502" class="LineNr">502 </span>  <span class="Delimiter">{</span>
<span id="L503" class="LineNr">503 </span>    <span class="PreProc">break-if-!=</span>
<span id="L504" class="LineNr">504 </span>    <span class="PreProc">return</span> <span class="Constant">2</span>  <span class="muComment"># for &quot;-0&quot;</span>
<span id="L505" class="LineNr">505 </span>  <span class="Delimiter">}</span>
<span id="L506" class="LineNr">506 </span>  compare bits, <span class="Constant">0x7f800000</span>
<span id="L507" class="LineNr">507 </span>  <span class="Delimiter">{</span>
<span id="L508" class="LineNr">508 </span>    <span class="PreProc">break-if-!=</span>
<span id="L509" class="LineNr">509 </span>    <span class="PreProc">return</span> <span class="Constant">3</span>  <span class="muComment"># for &quot;Inf&quot;</span>
<span id="L510" class="LineNr">510 </span>  <span class="Delimiter">}</span>
<span id="L511" class="LineNr">511 </span>  compare bits, <span class="Constant">0xff800000</span>
<span id="L512" class="LineNr">512 </span>  <span class="Delimiter">{</span>
<span id="L513" class="LineNr">513 </span>    <span class="PreProc">break-if-!=</span>
<span id="L514" class="LineNr">514 </span>    <span class="PreProc">return</span> <span class="Constant">4</span>  <span class="muComment"># for &quot;-Inf&quot;</span>
<span id="L515" class="LineNr">515 </span>  <span class="Delimiter">}</span>
<span id="L516" class="LineNr">516 </span>  <span class="PreProc">var</span> exponent/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy bits
<span id="L517" class="LineNr">517 </span>  exponent <span class="Special">&lt;-</span> shift-right <span class="Constant">0x17</span>  <span class="muComment"># 23 bits of mantissa</span>
<span id="L518" class="LineNr">518 </span>  exponent <span class="Special">&lt;-</span> and <span class="Constant">0xff</span>
<span id="L519" class="LineNr">519 </span>  exponent <span class="Special">&lt;-</span> subtract <span class="Constant">0x7f</span>
<span id="L520" class="LineNr">520 </span>  compare exponent, <span class="Constant">0x80</span>
<span id="L521" class="LineNr">521 </span>  <span class="Delimiter">{</span>
<span id="L522" class="LineNr">522 </span>    <span class="PreProc">break-if-!=</span>
<span id="L523" class="LineNr">523 </span>    <span class="PreProc">return</span> <span class="Constant">3</span>  <span class="muComment"># for &quot;NaN&quot;</span>
<span id="L524" class="LineNr">524 </span>  <span class="Delimiter">}</span>
<span id="L525" class="LineNr">525 </span>  <span class="muComment"># - regular numbers</span>
<span id="L526" class="LineNr">526 </span>  <span class="muComment"># v = 1.mantissa (in base 2) &lt;&lt; 0x17</span>
<span id="L527" class="LineNr">527 </span>  <span class="PreProc">var</span> v/<span class="muRegEbx">ebx</span>: int <span class="Special">&lt;-</span> copy bits
<span id="L528" class="LineNr">528 </span>  v <span class="Special">&lt;-</span> and <span class="Constant">0x7fffff</span>
<span id="L529" class="LineNr">529 </span>  v <span class="Special">&lt;-</span> or <span class="Constant">0x00800000</span>  <span class="muComment"># insert implicit 1</span>
<span id="L530" class="LineNr">530 </span>  <span class="muComment"># e = exponent - 0x17</span>
<span id="L531" class="LineNr">531 </span>  <span class="PreProc">var</span> e/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy exponent
<span id="L532" class="LineNr">532 </span>  e <span class="Special">&lt;-</span> subtract <span class="Constant">0x17</span>  <span class="muComment"># move decimal place from before mantissa to after</span>
<span id="L533" class="LineNr">533 </span>
<span id="L534" class="LineNr">534 </span>  <span class="muComment"># initialize buffer with decimal representation of v</span>
<span id="L535" class="LineNr">535 </span>  <span class="PreProc">var</span> buf-storage: (array byte <span class="Constant">0x7f</span>)
<span id="L536" class="LineNr">536 </span>  <span class="PreProc">var</span> buf/<span class="muRegEdi">edi</span>: (addr array byte) <span class="Special">&lt;-</span> address buf-storage
<span id="L537" class="LineNr">537 </span>  <span class="PreProc">var</span> n/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> <a href='412render-float-decimal.mu.html#L251'>decimal-digits</a> v, buf
<span id="L538" class="LineNr">538 </span>  <a href='412render-float-decimal.mu.html#L268'>reverse-digits</a> buf, n
<span id="L539" class="LineNr">539 </span>
<span id="L540" class="LineNr">540 </span>  <span class="muComment"># loop if e &gt; 0</span>
<span id="L541" class="LineNr">541 </span>  <span class="Delimiter">{</span>
<span id="L542" class="LineNr">542 </span>    compare e, <span class="Constant">0</span>
<span id="L543" class="LineNr">543 </span>    <span class="PreProc">break-if-&lt;=</span>
<span id="L544" class="LineNr">544 </span>    n <span class="Special">&lt;-</span> <a href='412render-float-decimal.mu.html#L290'>double-array-of-decimal-digits</a> buf, n
<span id="L545" class="LineNr">545 </span>    e <span class="Special">&lt;-</span> decrement
<span id="L546" class="LineNr">546 </span>    <span class="PreProc">loop</span>
<span id="L547" class="LineNr">547 </span>  <span class="Delimiter">}</span>
<span id="L548" class="LineNr">548 </span>
<span id="L549" class="LineNr">549 </span>  <span class="PreProc">var</span> dp/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> copy n
<span id="L550" class="LineNr">550 </span>
<span id="L551" class="LineNr">551 </span>  <span class="muComment"># loop if e &lt; 0</span>
<span id="L552" class="LineNr">552 </span>  <span class="Delimiter">{</span>
<span id="L553" class="LineNr">553 </span>    compare e, <span class="Constant">0</span>
<span id="L554" class="LineNr">554 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L555" class="LineNr">555 </span>    n, dp <span class="Special">&lt;-</span> <a href='412render-float-decimal.mu.html#L341'>halve-array-of-decimal-digits</a> buf, n, dp
<span id="L556" class="LineNr">556 </span>    e <span class="Special">&lt;-</span> increment
<span id="L557" class="LineNr">557 </span>    <span class="PreProc">loop</span>
<span id="L558" class="LineNr">558 </span>  <span class="Delimiter">}</span>
<span id="L559" class="LineNr">559 </span>
<span id="L560" class="LineNr">560 </span>  compare dp, <span class="Constant">0</span>
<span id="L561" class="LineNr">561 </span>  <span class="Delimiter">{</span>
<span id="L562" class="LineNr">562 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L563" class="LineNr">563 </span>    <span class="PreProc">return</span> <span class="Constant">8</span>  <span class="muComment"># hacky for scientific notation</span>
<span id="L564" class="LineNr">564 </span>  <span class="Delimiter">}</span>
<span id="L565" class="LineNr">565 </span>  <span class="Delimiter">{</span>
<span id="L566" class="LineNr">566 </span>    <span class="PreProc">var</span> dp2/<span class="muRegEax">eax</span>: int <span class="Special">&lt;-</span> copy dp
<span id="L567" class="LineNr">567 </span>    compare dp2, precision
<span id="L568" class="LineNr">568 </span>    <span class="PreProc">break-if-&lt;=</span>
<span id="L569" class="LineNr">569 </span>    <span class="PreProc">return</span> <span class="Constant">8</span>  <span class="muComment"># hacky for scientific notation</span>
<span id="L570" class="LineNr">570 </span>  <span class="Delimiter">}</span>
<span id="L571" class="LineNr">571 </span>
<span id="L572" class="LineNr">572 </span>  <span class="muComment"># result = min(n, dp+3)</span>
<span id="L573" class="LineNr">573 </span>  <span class="PreProc">var</span> result/<span class="muRegEcx">ecx</span>: int <span class="Special">&lt;-</span> copy dp
<span id="L574" class="LineNr">574 </span>  result <span class="Special">&lt;-</span> add <span class="Constant">3</span>
<span id="L575" class="LineNr">575 </span>  <span class="Delimiter">{</span>
<span id="L576" class="LineNr">576 </span>    compare result, n
<span id="L577" class="LineNr">577 </span>    <span class="PreProc">break-if-&lt;=</span>
<span id="L578" class="LineNr">578 </span>    result <span class="Special">&lt;-</span> copy n
<span id="L579" class="LineNr">579 </span>  <span class="Delimiter">}</span>
<span id="L580" class="LineNr">580 </span>
<span id="L581" class="LineNr">581 </span>  <span class="muComment"># account for decimal point</span>
<span id="L582" class="LineNr">582 </span>  compare dp, n
<span id="L583" class="LineNr">583 </span>  <span class="Delimiter">{</span>
<span id="L584" class="LineNr">584 </span>    <span class="PreProc">break-if-&gt;=</span>
<span id="L585" class="LineNr">585 </span>    result <span class="Special">&lt;-</span> increment
<span id="L586" class="LineNr">586 </span>  <span class="Delimiter">}</span>
<span id="L587" class="LineNr">587 </span>
<span id="L588" class="LineNr">588 </span>  <span class="muComment"># account for sign</span>
<span id="L589" class="LineNr">589 </span>  <span class="PreProc">var</span> sign/<span class="muRegEdx">edx</span>: int <span class="Special">&lt;-</span> reinterpret in
<span id="L590" class="LineNr">590 </span>  sign <span class="Special">&lt;-</span> shift-right <span class="Constant">0x1f</span>
<span id="L591" class="LineNr">591 </span>  <span class="Delimiter">{</span>
<span id="L592" class="LineNr">592 </span>    compare sign, <span class="Constant">1</span>
<span id="L593" class="LineNr">593 </span>    <span class="PreProc">break-if-!=</span>
<span id="L594" class="LineNr">594 </span>    result <span class="Special">&lt;-</span> increment
<span id="L595" class="LineNr">595 </span>  <span class="Delimiter">}</span>
<span id="L596" class="LineNr">596 </span>  <span class="PreProc">return</span> result
<span id="L597" class="LineNr">597 </span><span class="Delimiter">}</span>
</pre>
</body>
</html>
<!-- vim: set foldmethod=manual : -->