summaryrefslogtreecommitdiff
path: root/05/util.b
blob: 9e7afbb887abb03697a2764fc457684bb7a7454c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
; multiply two 64-bit signed numbers to a 128-bit number
function full_multiply_signed
	argument a
	argument b
	argument p_lower
	argument p_upper
	local lower
	local upper
	
	lower = a * b
	; mov rax, rdx
	byte 0x48
	byte 0x89
	byte 0xd0
	; mov [rbp-48] (upper), rax
	byte 0x48
	byte 0x89
	byte 0x85
	byte 0xd0
	byte 0xff
	byte 0xff
	byte 0xff
	
	*8p_lower = lower
	*8p_upper = upper
	return


function divmod_unsigned
	argument a
	argument b
	argument p_quotient
	argument p_remainder
	local q
	local r
	
	; mov rax, [rbp-16]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xf0
	byte 0xff
	byte 0xff
	byte 0xff
	
	; mov rbx, rax
	byte 0x48
	byte 0x89
	byte 0xc3
	
	; mov rax, [rbp-8]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xf8
	byte 0xff
	byte 0xff
	byte 0xff
	
	; xor edx, edx
	byte 0x31
	byte 0xd2
	
	; div rbx
	byte 0x48
	byte 0xf7
	byte 0xf3
	
	; mov [rbp-40], rax
	byte 0x48
	byte 0x89
	byte 0x85
	byte 0xd8
	byte 0xff
	byte 0xff
	byte 0xff
	
	; mov rax, rdx
	byte 0x48
	byte 0x89
	byte 0xd0
	
	; mov [rbp-48], rax
	byte 0x48
	byte 0x89
	byte 0x85
	byte 0xd0
	byte 0xff
	byte 0xff
	byte 0xff
	
	*8p_quotient = q
	*8p_remainder = r
	
	return

; allows for negative shifts
function right_shift
	argument x
	argument n
	if n < 0 goto right_shift_negative
	return x > n
	:right_shift_negative
	n = 0 - n
	return x < n

; allows for negative shifts
function left_shift
	argument x
	argument n
	if n < 0 goto right_shift_negative
	return x < n
	:left_shift_negative
	n = 0 - n
	return x > n

function max_signed
	argument a
	argument b
	if a > b goto maxs_return_a
	return b
	:maxs_return_a
	return a
	
function file_error
	argument name
	fputs(2, .str_file_error)
	fputs(2, name)
	fputc(2, 10)
	exit(1)

:str_file_error
	string Error opening file:
	byte 32
	byte 0

function die
	argument message
	fputs(2, message)
	exit(1)

function ftruncate
	argument fd
	argument length
	local x
	x = syscall(77, fd, length)
	if x != 0 goto ftruncate_failed
	return
	
:ftruncate_failed
	fputs(2, .str_ftruncate_failed)
	exit(1)
:str_ftruncate_failed
	string ftruncated failed.
	byte 10
	byte 0

function mmap
	argument addr
	argument length
	argument prot
	argument flags
	argument fd
	argument offset
	return syscall(9, addr, length, prot, flags, fd, offset)

function munmap
	argument addr
	argument length
	return syscall(11, addr, length)

#define PROT_READ 1
#define PROT_WRITE 2
#define PROT_READ_WRITE 3
#define MAP_SHARED 0x01
#define MAP_PRIVATE_ANONYMOUS 0x22

function malloc
	argument size
	local total_size
	local memory
	total_size = size + 8
	memory = mmap(0, total_size, PROT_READ_WRITE, MAP_PRIVATE_ANONYMOUS, -1, 0)
	if memory ] 0xffffffffffff0000 goto malloc_failed
	*8memory = total_size
	return memory + 8

:malloc_failed
	fputs(2, .str_out_of_memory)
	exit(1)
	
:str_out_of_memory
	string Out of memory.
	byte 10
	byte 0

function free
	argument memory
	local psize
	local size
	psize = memory - 8
	size = *8psize
	munmap(psize, size)
	return

; returns a pointer to a null-terminated string containing the
; (unsigned) number given
function itos
	global 32 itos_string
	argument x
	local c
	local p
	p = &itos_string
	p += 30
	:itos_loop
		divmod_unsigned(x, 10, &x, &c)
		c += '0
		*1p = c
		if x == 0 goto itos_loop_end
		p -= 1
		goto itos_loop
	:itos_loop_end
	return p

; returns the number in the given base at the start of the string, advancing the string past it.
function strtoi
	argument p_s
	argument base
	local s
	local c
	local n
	n = 0
	s = *8p_s
	:strtoi_loop
		c = *1s
		if c < '0 goto strtoi_loop_end
		if c <= '9 goto strtoi_decimal_digit
		if c < 'A goto strtoi_loop_end
		if c <= 'F goto strtoi_upper_hexdigit
		if c < 'a goto strtoi_loop_end
		if c <= 'f goto strtoi_lower_hexdigit
		goto strtoi_loop_end
		
		:strtoi_decimal_digit
			c -= '0
			goto strtoi_digit
		:strtoi_upper_hexdigit
			c += 10 - 'A
			goto strtoi_digit
		:strtoi_lower_hexdigit
			c += 10 - 'a
			goto strtoi_digit
		:strtoi_digit
			if c >= base goto strtoi_loop_end
			n *= base
			n += c
			s += 1
			goto strtoi_loop
			
	:strtoi_loop_end
	*8p_s = s
	return n
	
; returns the decimal number at the start of the given string
function stoi
	argument s
	return strtoi(&s, 10)

function memchr
	argument mem
	argument c
	local p
	p = mem
	:memchr_loop
		if *1p == c goto memchr_loop_end
		p += 1
		goto memchr_loop
	:memchr_loop_end
	return p

function strchr
	argument str
	argument c
	local p
	p = str
	:strchr_loop
		if *1p == 0 goto return_0
		if *1p == c goto strchr_loop_end
		p += 1
		goto strchr_loop
	:strchr_loop_end
	return p

; copy from *p_src to *p_dest until terminator is reached, setting both to point to their respective terminators
function memccpy_advance
	argument p_dest
	argument p_src
	argument terminator
	local src
	local dest
	local c
	src = *8p_src
	dest = *8p_dest
	:memccpy_advance_loop
		c = *1src
		*1dest = c
		if c == terminator goto memccpy_advance_loop_end
		src += 1
		dest += 1
		goto memccpy_advance_loop
	:memccpy_advance_loop_end
	*8p_src = src
	*8p_dest = dest
	return

; copy from src to dest until terminator is reached, returning pointer to terminator in dest.
function memccpy
	argument dest
	argument src
	argument terminator
	memccpy_advance(&dest, &src, terminator)
	return dest

; like C, but returns 0
function memcpy
	argument dest
	argument src
	argument n
	local p
	local q
	p = dest
	q = src
	:memcpy_loop
		if n == 0 goto return_0
		*1p = *1q
		p += 1
		q += 1
		n -= 1
		goto memcpy_loop

function strlen
	argument s
	local p
	p = s
	:strlen_loop
		if *1p == 0 goto strlen_loop_end
		p += 1
		goto strlen_loop
	:strlen_loop_end
	return p - s

; like C strcpy, but returns a pointer to the terminating null character in dest
function strcpy
	argument dest
	argument src
	local p
	local q
	local c
	p = dest
	q = src
	:strcpy_loop
		c = *1q
		*1p = c
		if c == 0 goto strcpy_loop_end
		p += 1
		q += 1
		goto strcpy_loop
	:strcpy_loop_end
	return p

function str_equals
	argument a
	argument b
	local c
	local d
	:str_equals_loop
		c = *1a
		d = *1b
		if c != d goto return_0
		if c == 0 goto return_1
		a += 1
		b += 1
		goto str_equals_loop

function str_startswith
	argument s
	argument prefix
	local p
	local q
	local c1
	local c2
	p = s
	q = prefix
	:str_startswith_loop
		c1 = *1p
		c2 = *1q
		if c2 == 0 goto return_1
		if c1 != c2 goto return_0
		p += 1
		q += 1
		goto str_startswith_loop

function fputs
	argument fd
	argument s
	local length
	length = strlen(s)
	syscall(1, fd, s, length)
	return

function puts
	argument s
	fputs(1, s)
	return

function putsln
	argument s
	fputs(1, s)
	fputc(1, 10)
	return


function print_separator
	fputs(1, .str_separator)
	return

:str_separator
	byte 10
	string ------------------------------------------------
	byte 10
	byte 0

function fputn
	argument fd
	argument n
	local s
	s = itos(n)
	fputs(fd, s)
	return

function fputn_signed
	argument fd
	argument n
	if n < 0 goto fputn_negative
	
	fputn(fd, n)
	return
	
	:fputn_negative
		fputc(fd, '-)
		n = 0 - n
		fputn(fd, n)
		return
		
:hex_digits
	string 0123456789abcdef

function fputx64
	argument fd
	argument n
	local m
	local x
	m = 60
	:fputx64_loop
		x = n > m
		x &= 0xf
		x += .hex_digits
		fputc(fd, *1x)
		m -= 4
		if m >= 0 goto fputx64_loop
	return
function putx64
	argument n
	fputx64(1, n)
	return
function putx64ln
	argument n
	fputx64(1, n)
	fputc(1, 10)
	return
	
function fputx32
	argument fd
	argument n
	local m
	local x
	m = 28
	:fputx32_loop
		x = n > m
		x &= 0xf
		x += .hex_digits
		fputc(fd, *1x)
		m -= 4
		if m >= 0 goto fputx32_loop
	return
function putx32
	argument n
	fputx32(1, n)
	return
function putx32ln
	argument n
	fputx32(1, n)
	fputc(1, 10)
	return

function putn
	argument n
	fputn(1, n)
	return

function putn_signed
	argument n
	fputn_signed(1, n)
	return

function putnln
	argument n
	fputn(1, n)
	fputc(1, 10)
	return

function putnln_signed
	argument n
	fputn_signed(1, n)
	fputc(1, 10)
	return


function fputc
	argument fd
	argument c
	syscall(1, fd, &c, 1)
	return

function putc
	argument c
	fputc(1, c)
	return
function putcln
	argument c
	fputc(1, c)
	fputc(1, 10)
	return

; returns 0 at end of file
function fgetc
	argument fd
	local c
	c = 0
	syscall(0, fd, &c, 1)
	return c

; read a line from fd as a null-terminated string
; returns 0 at end of file, 1 otherwise
function fgets
	argument fd
	argument buf
	argument size
	local p
	local end
	local c
	p = buf
	end = buf + size
	
	:fgets_loop
		c = fgetc(fd)
		if c == 0 goto fgets_eof
		if c == 10 goto fgets_eol
		*1p = c
		p += 1
		if p == end goto fgets_eob
		goto fgets_loop
		
	:fgets_eol ; end of line
	*1p = 0
	return 1
	:fgets_eof ; end of file
	*1p = 0
	return 0
	:fgets_eob ; end of buffer
	p -= 1
	*1p = 0
	return 1

; open the given file for reading
function open_r
	argument filename
	local fd
	fd = syscall(2, filename, 0)
	if fd < 0 goto open_r_error
		return fd
	:open_r_error
		file_error(filename)
		return -1

; open the given file for writing with the given mode
function open_w
	argument filename
	argument mode
	local fd
	fd = syscall(2, filename, 0x241, mode)
	if fd < 0 goto open_w_error
		return fd
	:open_w_error
		file_error(filename)
		return -1

; open the given file for reading and writing with the given mode
function open_rw
	argument filename
	argument mode
	local fd
	fd = syscall(2, filename, 0x242, mode)
	if fd < 0 goto open_rw_error
		return fd
	:open_rw_error
		file_error(filename)
		return -1
	
function close
	argument fd
	syscall(3, fd)
	return

#define SEEK_SET 0
#define SEEK_CUR 1
#define SEEK_END 2

function lseek
	argument fd
	argument offset
	argument whence
	return syscall(8, fd, offset, whence)

function isupper
	argument c
	if c < 'A goto return_0
	if c <= 'Z goto return_1
	goto return_0

function islower
	argument c
	if c < 'a goto return_0
	if c <= 'z goto return_1
	goto return_0

function isdigit
	argument c
	if c < '0 goto return_0
	if c <= '9 goto return_1
	goto return_0

function isoctdigit
	argument c
	if c < '0 goto return_0
	if c <= '7 goto return_1
	goto return_0	

function isalpha
	argument c
	if c < 'A goto return_0
	if c <= 'Z goto return_1
	if c < 'a goto return_0
	if c <= 'z goto return_1
	goto return_0

; characters which can start identifiers in C
function isalpha_or_underscore
	argument c
	if c < 'A goto return_0
	if c <= 'Z goto return_1
	if c == '_ goto return_1
	if c < 'a goto return_0
	if c <= 'z goto return_1
	goto return_0

; characters which can appear in identifiers in C
function isalnum_or_underscore
	argument c
	if c < '0 goto return_0
	if c <= '9 goto return_1
	if c < 'A goto return_0
	if c <= 'Z goto return_1
	if c == '_ goto return_1
	if c < 'a goto return_0
	if c <= 'z goto return_1
	goto return_0

; is the given character one of:
;   .0123456789
; (these are the characters which can appear at the start of a number in C)
function isdigit_or_dot
	argument c
	if c < '. goto return_0
	if c == '. goto return_1
	if c < '0 goto return_0
	if c <= '9 goto return_1
	goto return_0

function exit
	argument status_code
	syscall(0x3c, status_code)

; return index of leftmost bit
; error on 0
function leftmost_1bit
	argument x
	local i
	local b
	if x == 0 goto leftmost1bit_0
	
	i = 63
	:leftmost1bit_loop
		b = 1 < i
		b &= x
		if b != 0 goto leftmost1bit_found
		i -= 1
		goto leftmost1bit_loop
	:leftmost1bit_found
		return i
	:leftmost1bit_0
		fputs(2, .str_leftmost1bit_0)
		exit(1)
	:str_leftmost1bit_0
		string 0 passed to leftmost_1bit.
		byte 0

:empty_string
	byte 0

:return_0
	return 0
:return_1
	return 1
:return_2
	return 2
:return_3
	return 3
:return_4
	return 4
:return_5
	return 5
:return_6
	return 6
:return_7
	return 7
:return_8
	return 8
:return_9
	return 9
:return_minus1
	return -1
:return_0x10
	return 0x10
:return_0x20
	return 0x20
:return_0x30
	return 0x30
:return_0x40
	return 0x40
:return_0x50
	return 0x50
:return_0x60
	return 0x60
:return_0x70
	return 0x70
:return_0x80
	return 0x80
:return_0x90
	return 0x90
:return_0xa0
	return 0xa0
:return_0xb0
	return 0xb0
:return_0xc0
	return 0xc0
:return_0xd0
	return 0xd0
:return_0xd8
	return 0xd8
:return_0xe0
	return 0xe0
:return_0xf0
	return 0xf0
:return_0xffff
	return 0xffff

function syscall
	; I've done some testing, and this should be okay even if
	; rbp-56 goes beyond the end of the stack.
	; mov rax, [rbp-16]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xf0
	byte 0xff
	byte 0xff
	byte 0xff
	; mov rdi, rax
	byte 0x48
	byte 0x89
	byte 0xc7
	
	; mov rax, [rbp-24]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xe8
	byte 0xff
	byte 0xff
	byte 0xff
	; mov rsi, rax
	byte 0x48
	byte 0x89
	byte 0xc6
	
	; mov rax, [rbp-32]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xe0
	byte 0xff
	byte 0xff
	byte 0xff
	; mov rdx, rax
	byte 0x48
	byte 0x89
	byte 0xc2
	
	; mov rax, [rbp-40]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xd8
	byte 0xff
	byte 0xff
	byte 0xff
	; mov r10, rax
	byte 0x49
	byte 0x89
	byte 0xc2
	
	; mov rax, [rbp-48]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xd0
	byte 0xff
	byte 0xff
	byte 0xff
	; mov r8, rax
	byte 0x49
	byte 0x89
	byte 0xc0
	
	; mov rax, [rbp-56]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xc8
	byte 0xff
	byte 0xff
	byte 0xff
	; mov r9, rax
	byte 0x49
	byte 0x89
	byte 0xc1
	
	; mov rax, [rbp-8]
	byte 0x48
	byte 0x8b
	byte 0x85
	byte 0xf8
	byte 0xff
	byte 0xff
	byte 0xff
	
	; syscall
	byte 0x0f
	byte 0x05
	
	return