summaryrefslogtreecommitdiff
path: root/gcc/config/c4x/libgcc.S
blob: 8f801da6af76e3357f3e87793b8b7ab4b13d4523 (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
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
/* libgcc routines for the Texas Instruments TMS320C[34]x
   Copyright (C) 1997,98, 1999 Free Software Foundation, Inc.

 Contributed by Michael Hayes (m.hayes@elec.canterbury.ac.nz)
            and Herman Ten Brugge (Haj.Ten.Brugge@net.HCC.nl).

	
This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

In addition to the permissions in the GNU General Public License, the
Free Software Foundation gives you unlimited permission to link the
compiled version of this file into combinations with other programs,
and to distribute those combinations without any restriction coming
from the use of this file.  (The General Public License restrictions
do apply in other respects; for example, they cover modification of
the file, and distribution when not linked into a combine
executable.)

This file is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; see the file COPYING.  If not, write to
the Free Software Foundation, 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */

; These routines are called using the standard TI register argument
; passing model.
; The following registers do not have to be saved:
; r0, r1, r2, r3, ar0, ar1, ar2, ir0, ir1, bk, rs, rc, re, (r9, r10, r11)
;
; Perform floating point divqf3
;
; This routine performs a reciprocal of the divisor using the method
; described in the C30/C40 user manuals.  It then multiplies that
; result by the dividend.
; 
; Let r be the reciprocal of the divisor v and let the ith estimate
; of r be denoted by r[i].  An iterative approach can be used to
; improve the estimate of r, given an initial estimate r[0], where
;
; r[i + 1] = r[i] * (2.0 - v * r[i])
;
; The normalized error e[i] at the ith iteration is
;
; e[i] = (r - r[i]) / r = (1 / v - r[i]) * v = (1 - v * r[i])
;
; Note that 
;
; e[i + 1]  = (1 - v * r[i + 1]) = 1 - 2 * v * r[i] + v^2 + (r[i])^2
;           = (1 - v * r[i])^2 = (e[i])^2

; r2 dividend, r3 divisor, r0 quotient
; clobbers r1, ar1
#ifdef L_divsf3
	.text
        .global ___divqf3
___divqf3:

#ifdef _TMS320C4x
	.if .REGPARM == 0
	lda	sp,ar0
	ldf	*-ar0(2), r3
	.endif

	pop	ar1		; Pop return address

; r0 = estimate of r, r1 = tmp, r2 = dividend, r3 = divisor
        rcpf    r3, r0		; Compute initial estimate r[0]

	mpyf3	r0, r3, r1	; r1 = r[0] * v
	subrf	2.0, r1		; r1 = 2.0 - r[0] * v
	mpyf	r1, r0		; r0 = r[0] * (2.0 - r[0] * v) = r[1]
; End of 1st iteration (16 bits accuracy)

	mpyf3	r0, r3, r1	; r1 = r[1] * v
	subrf	2.0, r1		; r1 = 2.0 - r[1] * v

	bud	ar1		; Delayed branch
	mpyf	r1, r0		; r0 = r[1] * (2.0 - r[1] * v) = r[2]
; End of 2nd iteration (32 bits accuracy)
	.if .REGPARM == 0
	mpyf	*-ar0(1), r0	; Multiply by the dividend
	.else
	mpyf	r2, r0		; Multiply by the dividend
	.endif
	rnd	r0
	; Branch occurs here
#else
	.if .REGPARM == 0
	ldiu	sp,ar0
	ldf	*-ar0(2), r3
	.endif

	pop	ar1		; Pop return address

; Initial estimate       r[0] = 1.0 * 2^(-e - 1)
; where                  v = m * 2^e

; r0 = estimate of r, r1 = tmp, r2 = dividend, r3 = divisor

; Calculate initial estimate r[0]
	pushf	r3
	pop	r0
	not	r0		; r0 = -e
				; complement exponent = -e -1
				; complement sign (side effect)
				; complement mantissa (almost 3 bit accurate)
	push	r0
	popf	r0		; r0 = 1.0 * e^(-e - 1) + inverted mantissa
	ldf	-1.0, r1	; undo complement sign bit
	xor	r1, r0

	mpyf3	r0, r3, r1	; r1 = r[0] * v
	subrf	2.0, r1		; r1 = 2.0 - r[0] * v
	mpyf	r1, r0		; r0 = r[0] * (2.0 - r[0] * v) = r[1]
; End of 1st iteration

	mpyf3	r0, r3, r1	; r1 = r[1] * v
	subrf	2.0, r1		; r1 = 2.0 - r[1] * v
	mpyf	r1, r0		; r0 = r[1] * (2.0 - r[1] * v) = r[2]
; End of 2nd iteration

	mpyf3	r0, r3, r1	; r1 = r[2] * v
	subrf	2.0, r1		; r1 = 2.0 - r[2] * v
	mpyf	r1, r0		; r0 = r[2] * (2.0 - r[2] * v) = r[3]
; End of 3rd iteration

	rnd	r0		; Minimize error in x[3]'s LSBs

; Use modified last iteration
; r[4] = (r[3] * (1.0 - (v * r[3]))) + r[3]
	mpyf3	r0, r3, r1	; r1 = r[3] * v
	subrf	1.0, r1		; r1 = 1.0 - r[3] * v
	mpyf	r0, r1		; r1 = r[3] * (1.0 - r[3] * v)
	addf	r1, r0		; r0 = r[3] * (1.0 - r[3] * v) + r[3] = r[4]

        rnd     r0              ; Minimize error in x[4]'s LSBs

	bud	ar1		; Delayed branch

        .if .REGPARM == 0
        ldfu    *-ar0(1), r2    ; Dividend in mem has only 24 bits significance
        .else
        rnd     r2              ; Minimize error in reg dividend's LSBs
				; since this may have 32 bit significance
        .endif

        mpyf    r2, r0          ; Multiply by the dividend
        rnd     r0              ; Round result to 32 bits

	; Branch occurs here
#endif

#endif
;
; Integer signed division
;
; ar2 dividend, r2 divisor, r0 quotient
; clobbers r1, r3, ar0, ar1, ir0, ir1, rc, rs, re
#ifdef L_divsi3
	.text
	.global ___divqi3
	.ref	udivqi3n
___divqi3:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	ldi	*-ar0(2), r2
	.endif

	xor3	ar2, r2, r3	; Get the sign
	absi	ar2, r0
	bvd	divq32
	ldi	r0, ar2
	absi	r2, r2
	cmpi	ar2, r2		; Divisor > dividend?

	pop	ir1
	bhid	zero		; If so, return 0

;
; Normalize oeprands.  Use difference exponents as shift count
; for divisor, and as repeat count for "subc"
;
	float	ar2, r1		; Normalize dividend
	pushf	r1		; Get as integer
	pop	ar0
	lsh	-24, ar0	; Get exponent
	
	float	r2, r1		; Normalize divisor
	pushf	r1		; Get as integer
	pop	ir0
	lsh	-24, ir0	; Get exponent

	subi	ir0, ar0	; Get difference of exponents
	lsh	ar0, r2		; Align divisor with dividend

;
; Do count + 1 subtracts and shifts
;
	rpts	ar0
		subc	r2, ar2

;
; Mask off the lower count+1 bits of ar2
;
	subri	31, ar0		; Shift count is (32 - (ar0 + 1))
	lsh	ar0, ar2	; Shift left
	negi	ar0, ar0
	lsh3	ar0, ar2, r0	; Shift right and put result in r0

;
; Check sign and negate result if necessary
;
	bud	ir1		; Delayed return
	negi	r0, r1		; Negate result
	ash	-31, r3		; Check sign
	ldinz	r1, r0		; If set, use negative result
	; Branch occurs here

zero:	bud	ir1		; Delayed branch
	ldi	0, r0
	nop
	nop
	; Branch occurs here
;
; special case where ar2 = abs(ar2) = 0x80000000.  We handle this by
; calling unsigned divide and negating the result if necessary.
;
divq32:
	push	r3		; Save sign
	call	udivqi3n
	pop	r3
	pop	ir1
	bd	ir1
	negi	r0, r1		; Negate result
	ash	-31, r3		; Check sign
	ldinz	r1, r0		; If set, use negative result
	; Branch occurs here
#endif
;
;
; ar2 dividend, r2 divisor, r0 quotient, 
; clobbers r1, r3, ar0, ar1, ir0, ir1, rc, rs, re
#ifdef L_udivsi3
	.text
	.global ___udivqi3
	.global udivqi3n
___udivqi3:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	ldi	*-ar0(2), r2
	.endif

udivqi3n:
	pop	ir1

	cmpi	ar2, r2		; If divisor > dividend
	bhi	qzero		; return zero
	ldi	r2, ar1		; Store divisor in ar1

	tstb	ar2, ar2	; Check top bit, jump if set to special handler
	bld	div_32		; Delayed branch

;
; Get divisor exponent
;
	float	ar1, r1		; Normalize the divisor
	pushf	r1		; Get into int register
	pop	rc
	; branch occurs here

	bzd	qzero		; if (float) divisor zero, return zero

	float	ar2, r1		; Normalize the dividend
	pushf	r1		; Get into int register
	pop	ar0
	lsh	-24, ar0	; Get both the exponents
	lsh	-24, rc

	subi	rc, ar0		; Get the difference between the exponents
	lsh	ar0, ar1	; Normalize the divisor with the dividend

;
; Do count_1 subtracts and shifts
;
	rpts	ar0
		subc	ar1, ar2

;
; mask off the lower count+1 bits
;
	subri	31, ar0		; Shift count (31 - (ar0+1))
	bud	ir1		; Delayed return
	lsh3	ar0, ar2, r0
	negi	ar0, ar0
	lsh	ar0, r0
	; Branch occurs here

;
; Handle a full 32-bit dividend
;
div_32:	tstb	ar1, ar1
	bld	qone		; if divisor high bit is one, the result is one
	lsh	-24, rc
	subri	31, rc
	lsh	rc, ar1		; Line up the divisor

;
; Now divisor and dividend are aligned.  Do first SUBC by hand, save
; of the forst quotient digit.  Then, shift divisor right rather
; than shifting dividend left.  This leaves a zero in the top bit of
; the dividend
;
	ldi	1, ar0		; Initizialize MSB of quotient
	lsh	rc, ar0		; create a mask for MSBs
	subi	1, ar0		; mask is (2 << count) - 1

	subi3	ar1, ar2, r1
	ldihs	r1, ar2
	ldihs	1, r1
	ldilo	0, r1
	lsh	rc, r1

	lsh	-1, ar1
	subi	1, rc
;
; do the rest of the shifts and subtracts
;
	rpts	rc
		subc	ar1, ar2

	bud	ir1
	and	ar0, ar2
	or3	r1, ar2, r0
	nop

qone:
	bud	ir1
	ldi	1, r0
	nop
	nop

qzero:
	bud	ir1
	ldi	0, r0
	nop
	nop
#endif

#ifdef L_umodsi3
	.text
	.global	___umodqi3
	.global	umodqi3n
___umodqi3:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	ldi	*-ar0(2), r2
	.endif

umodqi3n:
	pop     ir1		; return address
        cmpi    ar2, r2		; divisor > dividend ? 
	bhi     uzero		;    if so, return dividend
	ldi     r2, ar1		; load divisor
;
; If top bit of dividend is set, handle specially.
;
        tstb    ar2, ar2	; check top bit
	bld     umod_32		; get divisor exponent, then jump.
;
; Get divisor exponent by converting to float.
;
	float   ar1, r1		; normalize divisor
	pushf   r1		; push as float
	pop     rc		; pop as int to get exponent
        bzd     uzero		; if (float)divisor was zero, return
;
; 31 or less bits in dividend.  Get dividend exponent.
;
        float   ar2, r1		; normalize dividend
	pushf   r1		; push as float
	pop     ar0		; pop as int to get exponent
;
; Use difference in exponents as shift count to line up MSBs.
;
	lsh     -24, rc		; divisor exponent
	lsh     -24, ar0	; dividend exponent
	subi    rc, ar0		; difference
        lsh     ar0, ar1	; shift divisor up
; 
; Do COUNT+1 subtract & shifts.
;
	rpts    ar0
		subc    ar1, ar2  
;
;  Remainder is in upper 31-COUNT bits.
;
	bud     ir1		; delayed branch to return
	addi    1, ar0		; shift count is COUNT+1
	negi    ar0, ar0	; negate for right shift
	lsh3    ar0, ar2, r0	; shift to get result
	; Return occurs here

;
; The following code handles cases of a full 32-bit dividend.  Before
; SUBC can be used, the top bit must be cleared (otherwise SUBC can
; possibly shift a significant 1 out the top of the dividend).  This
; is accomplished by first doing a normal subtraction, then proceeding
; with SUBCs. 
;
umod_32:
;
; If the top bit of the divisor is set too, the remainder is simply
; the difference between the dividend and divisor.  Otherwise, shift 
; the divisor up to line up the MSBs.
;
	tstb    ar1, ar1	; check divisor
	bld     uone		; if negative, remainder is diff

	lsh     -24, rc		; divisor exponent
	subri   31, rc		; shift count = 31 - exp
	negi    rc, ar0		; used later as shift count
	lsh     rc, ar1		; shift up to line up MSBs
;
; Now MSBs are aligned.  Do first SUBC by hand using a plain subtraction.
; Then, shift divisor right rather than shifting dividend left.  This leaves
; a 0 in the top bit of the dividend.
;
	subi3   ar1, ar2, r1	; subtract 
	ldihs   r1, ar2		; if positive, replace dividend
	subi    1, rc		; first iteration is done
	lsh     -1, ar1		; shift divisor down
; 
; Do EXP subtract & shifts.
;
	rpts    rc  
		subc    ar1, ar2   
;
;  Quotient is in EXP+1 LSBs; shift remainder (in MSBs) down.
;
	bud	ir1
	lsh3    ar0, ar2, r0	; COUNT contains -(EXP+1)
	nop
	nop
;
;  Return (dividend - divisor).
;
uone:	bud	ir1
	subi3   r2, ar2, r0  
	nop
	nop
;
;  Return dividend.
;
uzero:	bud	ir1
	ldi     ar2, r0		; set status from result
	nop
	nop
#endif

#ifdef L_modsi3
	.text
	.global	___modqi3
	.ref umodqi3n
___modqi3:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	ldi	*-ar0(2), r2
	.endif

; 
; Determine sign of result.  Get absolute value of operands.
; 
	ldi     ar2, ar0	; sign of result same as dividend
	absi    ar2, r0		; make dividend positive
	bvd     mod_32		; if still negative, escape
	absi    r2, r1		; make divisor positive
	ldi     r1, ar1		; save in ar1       
        cmpi    r0, ar1		; divisor > dividend ? 

        pop     ir1            ; return address
	bhid    return 		;   if so, return dividend
; 
; Normalize operands.  Use difference in exponents as shift count
; for divisor, and as repeat count for SUBC.
;
        float   r1, r1		; normalize divisor
        pushf   r1		; push as float 
	pop     rc		; pop as int
        bzd     return		; if (float)divisor was zero, return

        float   r0, r1		; normalize dividend
        pushf   r1		; push as float
        pop     r1		; pop as int 

	lsh     -24, rc		; get divisor exponent
	lsh     -24, r1		; get dividend exponent
	subi    rc, r1		; get difference in exponents
	lsh     r1, ar1		; align divisor with dividend
; 
; Do COUNT+1 subtract & shifts.
;
	rpts    r1
		subc    ar1, r0
;
;  Remainder is in upper bits of R0
;
	addi    1, r1		; shift count is -(r1+1)
	negi    r1, r1 
	lsh     r1, r0		; shift right
;
;  Check sign and negate result if necessary.
;
return:
	bud     ir1		; delayed branch to return
        negi    r0, r1		; negate result
	cmpi    0, ar0		; check sign
	ldin    r1, r0		; if set, use negative result
	; Return occurs here
;
; The following code handles cases of a full 32-bit dividend.  This occurs
; when R0 = abs(R0) = 080000000h.  Handle this by calling the unsigned mod
; function, then negating the result if necessary.
;
mod_32:
        push    ar0		; remember sign
	call    umodqi3n	; do divide

	brd     return		; return
	pop     ar0		; restore sign
        pop     ir1             ; return address
	nop
#endif

#ifdef L_unsfltconst
	.section .const
        .global ___unsfltconst
___unsfltconst:   .float 4294967296.0
#endif

#ifdef L_unsfltcompare
	.section .const
        .global ___unsfltcompare
___unsfltcompare: .float 2147483648.0
#endif

; Integer 32-bit signed multiplication
;
; The TMS320C3x MPYI instruction takes two 24-bit signed integers
; and produces a 48-bit signed result which is truncated to 32-bits.
;
; A 32-bit by 32-bit multiplication thus requires a number of steps.
;
; Consider the product of two 32-bit signed integers,
;
;	z = x * y
;
; where x = (b << 16) + a,  y = (d << 16) + c
;
; This can be expressed as
;
;	z = ((b << 16) + a) * ((d << 16) + c)
;
;          = ((b * d) << 32) + ((b * c + a * d) << 16) + a * c
;
; Let z = (f << 16) + e where f < (1 << 16).
;
; Since we are only interested in a 32-bit result, we can ignore the 
; (b * d) << 32 term, and thus
;
;	f = b * c + a * d,  e = a * c
;
; We can simplify things if we have some a priori knowledge of the
; operands, for example, if -32768 <= y <= 32767, then y = c and d = 0 and thus
;
;	f = b * c,  e = a * c
;
; ar2 multiplier, r2 multiplicand, r0 product
; clobbers r1, r2, r3
#ifdef L_mulsi3	
	.text
	.global	___mulqi3
___mulqi3:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	ldi	*-ar0(2), r2
	.endif

        pop     ir1		; return address
	ldi	ar2, r0		;
	and	0ffffh, r0	; a
	lsh	-16, ar2	; b
	ldi	r2, r3		; 
	and	0ffffh, r3	; c
	mpyi	r3, ar2		; c * b		
	lsh	-16, r2		; d
	mpyi	r0, r2		; a * d
	addi	ar2, r2		; c * b + a * d
	bd	ir1		; delayed branch to return
	lsh	16, r2		; (c * b + a * d) << 16
	mpyi	r3, r0		; a * c
	addi	r2, r0		; a * c + (c * b + a * d) << 16
; branch occurs here

#endif	

;
; Integer 64 by 64 multiply
; long1 and long2 on stack
; result in r0,r1
;
#ifdef L_muldi3
	.text
	.global	___mulhi3
#ifdef _TMS320C4x
___mulhi3:
	pop	ar0
	ldi	sp,ar2
	ldi	*-ar2(1),r2
	ldi	*-ar2(3),r3
	mpyi3	r2,r3,r0
	mpyuhi3	r2,r3,r1
	mpyi	*-ar2(2),r2
	bd	ar0
	mpyi	*-ar2(0),r3
	addi	r2,r1
	addi	r3,r1
#else
___mulhi3:
	ldi	sp,ar2
	ldi	-16,rs
	ldi	*-ar2(2),ar0
	ldi	*-ar2(4),ar1
	ldi	ar0,r2
	and	0ffffh,r2
	ldi	ar1,r3
	and	0ffffh,r3
	lsh	rs,ar0
	lsh	rs,ar1

	mpyi	r2,r3,r0
	mpyi	ar0,ar1,r1
	mpyi	r2,ar1,rc
	lsh	rs,rc,re
	addi	re,r1
	lsh	16,rc
	addi	rc,r0
	addc	0,r1
	mpyi	r3,ar0,rc
	lsh	rs,rc,re
	addi	re,r1
	lsh	16,rc
	addi	rc,r0
	addc	0,r1

	ldi	*-ar2(1),ar0
	ldi	ar0,r2
	and	0ffffh,r2
	lsh	rs,ar0
	mpyi	r2,r3,rc
	addi	rc,r1
	mpyi	r2,ar1,rc
	mpyi	r3,ar0,re
	addi	re,rc
	lsh	16,rc
	addi	rc,r1

	ldi	*-ar2(2),ar0
	ldi	*-ar2(3),ar1
	ldi	ar0,r2
	and	0ffffh,r2
	ldi	ar1,r3
	and	0ffffh,r3
	lsh	rs,ar0
	lsh	rs,ar1
	mpyi	r2,r3,rc
	addi	rc,r1
	mpyi	r2,ar1,rc
	mpyi	r3,ar0,re
	pop	ar0
	bd	ar0
	addi	re,rc
	lsh	16,rc
	addi	rc,r1
#endif
#endif

;
; Integer 32 by 32 multiply highpart unsigned
; src1 in ar2
; src2 in r2
; result in r0
;
#ifdef L_umuldi3_high
	.text
	.global	___umulhi3_high
___umulhi3_high:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	ldi	*-ar0(2), r2
	.endif

	ldi	-16,rs
	ldi	r2,r3
	and	0ffffh,r2
	ldi	ar2,ar1
	and	0ffffh,ar2
	lsh	rs,r3
	lsh	rs,ar1

	mpyi	ar2,r2,r1
	mpyi	ar1,r3,r0
	mpyi	ar2,r3,rc
	lsh	rs,rc,re
	addi	re,r0
	lsh	16,rc
	addi	rc,r1
	addc	0,r0
	mpyi	r2,ar1,rc
	lsh	rs,rc,re
	addi	re,r0
	pop	ar0
	bd	ar0
	lsh	16,rc
	addi	rc,r1
	addc	0,r0
#endif

;
; Integer 32 by 32 multiply highpart signed
; src1 in ar2
; src2 in r2
; result in r0
;
#ifdef L_smuldi3_high
	.text
	.global	___smulhi3_high
___smulhi3_high:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	ldi	*-ar0(2), r2
	.endif

	ldi	-16,rs
	ldi	0,rc
	subi3	ar2,rc,r0
	ldi	r2,r3
	ldilt	r0,rc
	subi3	r2,rc,r0
	ldi	ar2,ar1
	tstb	ar1,ar1
	ldilt	r0,rc
	and	0ffffh,r2
	and	0ffffh,ar2
	lsh	rs,r3
	lsh	rs,ar1

	mpyi	ar2,r2,r1
	mpyi	ar1,r3,r0
	addi	rc,r0
	mpyi	ar2,r3,rc
	lsh	rs,rc,re
	addi	re,r0
	lsh	16,rc
	addi	rc,r1
	addc	0,r0
	mpyi	r2,ar1,rc
	lsh	rs,rc,re
	addi	re,r0
	pop	ar0
	bd	ar0
	lsh	16,rc
	addi	rc,r1
	addc	0,r0
#endif

;
; Integer 64 by 64 unsigned divide
; long1 and long2 on stack
; divide in r0,r1
; modulo in r2,r3
; routine takes a maximum of 64*8+23=535 cycles = 21.4 us @ 50Mhz
;
#ifdef L_udivdi3
	.text
	.global	___udivhi3
	.global	___udivide
	.global	___umodulo
	.ref udivqi3n
	.ref umodqi3n
___udivhi3:
	ldi	sp,ar2
	ldi     *-ar2(4),ar0
	ldi     *-ar2(3),ar1
	ldi     *-ar2(2),r0
	ldi     *-ar2(1),r1

___udivide:
	or	r1,ar1,r2
	bne	udiv0
	ldi	ar0,r2
	ldi	r0,ar2
	call	udivqi3n
	ldiu	0,r1
	rets

___umodulo:
	or	r1,ar1,r2
	bne	udiv0
	ldi	ar0,r2
	ldi	r0,ar2
	call	umodqi3n
	ldi	r0,r2
	ldiu	0,r3
	rets

udiv0:
	tstb	ar1,ar1
	bne	udiv1
	tstb	ar0,ar0
	bn	udiv1

	ldiu	63,rc
#ifdef _TMS320C4x
	rptbd	udivend0
	ldiu	0,r2
	addi	r0,r0
	rolc	r1
#else
	ldiu	0,r2
	addi	r0,r0
	rolc	r1
	rptb	udivend0
#endif

	rolc	r2
	subi3	ar0,r2,r3
	ldinc	r3,r2
	rolc	r0
udivend0:
	rolc	r1

	not	r0
	not	r1
	ldiu	0,r3
	rets
udiv1:
	push	r4
	push	r5
	ldiu	63,rc
	ldiu	0,r2
#ifdef _TMS320C4x
	rptbd	udivend1
	ldiu	0,r3
	addi	r0,r0
	rolc	r1
#else
	ldiu	0,r3
	addi	r0,r0
	rolc	r1
	rptb	udivend1
#endif

	rolc	r2
	rolc	r3
	subi3	ar0,r2,r4
	subb3	ar1,r3,r5
	ldinc	r4,r2
	ldinc	r5,r3
	rolc	r0
udivend1:
	rolc	r1

	not	r0
	not	r1
	pop	r5
	pop	r4
	rets
#endif

;
; Integer 64 by 64 unsigned modulo
; long1 and long2 on stack
; result in r0,r1
;
#ifdef L_umoddi3
	.text
	.global	___umodhi3
	.ref ___modulo
___umodhi3:
	ldi	sp,ar2
	ldi     *-ar2(4),ar0
	ldi     *-ar2(3),ar1
	ldi     *-ar2(2),r0
	ldi     *-ar2(1),r1
	call	___umodulo
	pop	ar0
	bd	ar0
	ldi	r2,r0
	ldi	r3,r1
	nop
#endif

;
; Integer 64 by 64 signed divide
; long1 and long2 on stack
; result in r0,r1
;
#ifdef L_divdi3
	.text
	.global	___divhi3
	.ref ___udivide
___divhi3:
	ldi	0,ir0
	ldi	sp,ar2
	ldi     *-ar2(4),r0
	ldi     *-ar2(3),r1
	bge	div1
	not	ir0
	negi	r0
	negb	r1
div1:
	ldi	r0,ar0
	ldi	r1,ar1
	ldi     *-ar2(2),r0
	ldi     *-ar2(1),r1
	bge	div2
	not	ir0
	negi	r0
	negb	r1
div2:
	call	___udivide
	tstb	ir0,ir0
	bge	div3
	negi	r0
	negb	r1
div3:	
	rets
#endif

;
; Integer 64 by 64 signed modulo
; long1 and long2 on stack
; result in r0,r1
;
#ifdef L_moddi3
	.text
	.global	___modhi3
	.ref ___umodulo
___modhi3:
	ldi	0,ir0
	ldi	sp,ar2
	ldi     *-ar2(4),r0
	ldi     *-ar2(3),r1
	bge	mod1
	not	ir0
	negi	r0
	negb	r1
mod1:
	ldi	r0,ar0
	ldi	r1,ar1
	ldi     *-ar2(2),r0
	ldi     *-ar2(1),r1
	bge	mod2
	not	ir0
	negi	r0
	negb	r1
mod2:
	call	___umodulo
	ldi	r2,r0
	ldi	r3,r1
	tstb	ir0,ir0
	bge	mod3
	negi	r0
	negb	r1
mod3:	
	rets
#endif

;
; double to signed long long conversion
; input in r2
; result in r0,r1
;
#ifdef L_fix_truncsfdi2
	.text
	.global	___fix_truncqfhi2
	.ref ufix_truncqfhi2n
___fix_truncqfhi2:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldf	*-ar0(1), r2
	.endif

	cmpf	0.0,r2
	bge	ufix_truncqfhi2n
	negf	r2
	call	ufix_truncqfhi2n
	negi	r0
	negb	r1
	rets
#endif

;
; double to unsigned long long conversion
; input in r2
; result in r0,r1
;
#ifdef L_ufix_truncsfdi2
	.text
	.global	___ufix_truncqfhi2
	.global	ufix_truncqfhi2n
___ufix_truncqfhi2:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldf	*-ar0(1), r2
	.endif

ufix_truncqfhi2n:
	cmpf	0.0,r2
	ble	ufix1
	pushf	r2
	pop	r3
	ash	-24,r3
	subi	31,r3
	cmpi	32,r3
	bgt	ufix1
	cmpi	-32,r3
	ble	ufix1
	ldi	1,r0
	ash	31,r0
	or3	r0,r2,r0
	ldi	r0,r1
	lsh3	r3,r0,r0
	subi	32,r3
	cmpi	-32,r3
	ldile	0,r1
	lsh3	r3,r1,r1
	rets
ufix1:
	ldi	0,r0
	ldi	0,r1
	rets
#endif

;
; signed long long to double conversion
; input on stack
; result in r0
;
#ifdef L_floatdisf2
	.text
	.global	___floathiqf2
	.ref ufloathiqf2n
___floathiqf2:
	ldi	sp,ar2
	ldi	*-ar2(2),r0
	ldi	*-ar2(1),r1
	bge	ufloathiqf2n
	negi	r0
	negb	r1
	call	ufloathiqf2n
	negf	r0
	rets
#endif

;
; unsigned long long to double conversion
; input on stack
; result in r0
;
#ifdef L_ufloatdisf2
	.text
	.global	___ufloathiqf2
	.global	ufloathiqf2n
	.ref ___unsfltconst
___ufloathiqf2:
	ldi	sp,ar2
	ldi	*-ar2(2),r0
	ldi	*-ar2(1),r1
ufloathiqf2n:
	.if .BIGMODEL
#ifdef _TMS320C4x
	ldpk	@___unsfltconst
#else
	ldp	@___unsfltconst
#endif
	.endif
	ldf	@___unsfltconst,r2
	float	r0
	bge	uflt1
	addf	r2,r0
uflt1:
	float	r1
	bge	uflt2
	addf	r2,r1
uflt2:
#ifdef _TMS320C4x
	pop	r3
	bd	r3
	mpyf	r2,r1
	addf	r1,r0
	nop
#else
	ldf	r1,r3
	and	0ffh,r3
	norm	r3,r3
	mpyf	r2,r3
	pop	ar2
	bd	ar2
	addf	r3,r0
	mpyf	r2,r1
	addf	r1,r0
#endif
#endif

;
; long double to signed long long conversion
; input in r2
; result in r0,r1
;
#ifdef L_fix_truncdfdi2
	.text
	.global	___fix_trunchfhi2
	.ref ufix_trunchfhi2n
___fix_trunchfhi2:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldf	*-ar0(2), r2
	ldi	*-ar0(1), r2
	.endif

	cmpf	0.0,r2
	bge	ufix_trunchfhi2n
	negf	r2
	call	ufix_trunchfhi2n
	negi	r0
	negb	r1
	rets
#endif

;
; long double to unsigned long long conversion
; input in r2
; result in r0,r1
;
#ifdef L_ufix_truncdfdi2
	.text
	.global	___ufix_trunchfhi2
	.global	ufix_trunchfhi2n
___ufix_trunchfhi2:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldf	*-ar0(2), r2
	ldi	*-ar0(1), r2
	.endif

ufix_trunchfhi2n:
	cmpf	0.0,r2
	ble	ufixh1
	pushf	r2
	pop	r3
	ash	-24,r3
	subi	31,r3
	cmpi	32,r3
	bgt	ufixh1
	cmpi	-32,r3
	ble	ufixh1
	ldi	1,r0
	ash	31,r0
	or3	r0,r2,r0
	ldi	r0,r1
	lsh3	r3,r0,r0
	subi	32,r3
	cmpi	-32,r3
	ldile	0,r1
	lsh3	r3,r1,r1
	rets
ufixh1:
	ldi	0,r0
	ldi	0,r1
	rets
#endif

;
; signed long long to long double conversion
; input on stack
; result in r0
;
#ifdef L_floatdidf2
	.text
	.global	___floathihf2
	.ref ufloathihf2n
___floathihf2:
	ldi	sp,ar2
	ldi	*-ar2(2),r0
	ldi	*-ar2(1),r1
	bge	ufloathihf2n
	negi	r0
	negb	r1
	call	ufloathihf2n
	negf	r0
	rets
#endif

;
; unsigned long long to double conversion
; input on stack
; result in r0
;
#ifdef L_ufloatdidf2
	.text
	.global	___ufloathihf2
	.global	ufloathihf2n
	.ref ___unsfltconst
___ufloathihf2:
	ldi	sp,ar2
	ldi	*-ar2(2),r0
	ldi	*-ar2(1),r1
ufloathihf2n
	.if .BIGMODEL
#ifdef _TMS320C4x
	ldpk	@___unsfltconst
#else
	ldp	@___unsfltconst
#endif
	.endif
	ldf	@___unsfltconst,r2
	float	r0
	bge	uflth1
	addf	r2,r0
uflth1:
	float	r1
	bge	uflth2
	addf	r2,r1
uflth2:
#ifdef _TMS320C4x
	pop	r3
	bd	r3
	mpyf	r2,r1
	addf	r1,r0
	nop
#else
	ldf	r1,r3
	and	0ffh,r3
	norm	r3,r3
	mpyf	r2,r3
	pop	ar2
	bd	ar2
	addf	r3,r0
	mpyf	r2,r1
	addf	r1,r0
#endif
#endif

;
; calculate ffs
; input in ar2
; result in r0
;
#ifdef L_ffs
	.global	___ffs
	.ref ___unsfltconst
	.text
___ffs:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldi	*-ar0(1), ar2
	.endif

	negi	ar2,r0
	and	ar2,r0
	float	r0,r0
	ldfu	0.0,r1
	.if .BIGMODEL
#ifdef _TMS320C4x
	ldpk	@___unsfltconst
#else
	ldp	@___unsfltconst
#endif
	.endif
	ldflt	@___unsfltconst,r1
	addf	r1,r0
	pushf	r0
	pop	r0
	pop	ar0
	bd	ar0
	ash	-24,r0
	ldilt	-1,r0
	addi	1,r0
#endif

;
; calculate long double * long double
; input in r2, r3
; output in r0
;
#ifdef L_muldf3
	.global ___mulhf3
	.text
___mulhf3:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldf	*-ar0(2), r2
	ldi	*-ar0(1), r2
	ldf	*-ar0(4), r3
	ldi	*-ar0(3), r3
	.endif

	pop	ar2		; return ad
	ldf	r2,r0		; copy lsb0
	ldf	r3,r1		; copy lsb1
	and	0ffh,r0		; mask lsb0
	and	0ffh,r1		; mask lsb1
	norm	r0,r0		; correct lsb0
	norm	r1,r1		; correct lsb1
	mpyf	r2,r1		; arg0*lsb1
	mpyf	r3,r0		; arg1*lsb0
	bd	ar2		; return (delayed)
	addf	r0,r1		; arg0*lsb1 + arg1*lsb0
	mpyf	r2,r3,r0	; msb0*msb1
	addf	r1,r0		; msb0*msb1 + arg0*lsb1 + arg1*lsb0
#endif

;
; calculate long double / long double
; r2 dividend, r3 divisor, r0 quotient
;
#ifdef L_divdf3
	.global ___divhf3
	.text
___divhf3:
	.if .REGPARM == 0
#ifdef _TMS320C4x
	lda	sp,ar0
#else
	ldiu	sp,ar0
#endif
	ldf	*-ar0(2), r2
	ldi	*-ar0(1), r2
	ldf	*-ar0(4), r3
	ldi	*-ar0(3), r3
	.endif

#ifdef _TMS320C4x
	pop	ar1
        rcpf    r3, r0
	mpyf3	r0, r3, r1
	subrf	2.0, r1		
	mpyf	r1, r0	
	mpyf3	r0, r3, r1
	bud	ar1
	subrf	2.0, r1	
	mpyf	r1, r0
	mpyf	r2, r0
#else
	pop	ar1
	pushf	r3
	pop	r0
	not	r0	
	push	r0
	popf	r0
	ldf	-1.0, r1
	xor	r1, r0

	mpyf3	r0, r3, r1	; r1 = r[0] * v
	subrf	2.0, r1		; r1 = 2.0 - r[0] * v
	mpyf	r1, r0		; r0 = r[0] * (2.0 - r[0] * v) = r[1]
; End of 1st iteration

	mpyf3	r0, r3, r1	; r1 = r[1] * v
	subrf	2.0, r1		; r1 = 2.0 - r[1] * v
	mpyf	r1, r0		; r0 = r[1] * (2.0 - r[1] * v) = r[2]
; End of 2nd iteration

	mpyf3	r0, r3, r1	; r1 = r[2] * v
	subrf	2.0, r1		; r1 = 2.0 - r[2] * v
	mpyf	r1, r0		; r0 = r[2] * (2.0 - r[2] * v) = r[3]
; End of 3rd iteration

	or	080h, r0
	rnd	r0

;	mpyf3	r0, r3, r1	; r1 = r[3] * v
	push	r4
	pushf	r4
	mpyf	r0, r3, r1

	ldf	r0, r4
	and	0ffh, r4
	norm	r4, r4
	mpyf	r3, r4
	addf	r4, r1

	ldf	r3, r4
	and	0ffh, r4
	norm 	r4, r4
	mpyf	r0, r4
	addf	r4, r1
	
	subrf	2.0, r1		; r1 = 2.0 - r[3] * v

	mpyf	r1, r0, r3	; r3 = r[3] * (2.0 - r[3] * v) = r[5]

	ldf	r1, r4
	and	0ffh, r4
	norm	r4, r4
	mpyf	r0, r4
	addf	r4, r3

	ldf	r0, r4
	and	0ffh, r4
	norm 	r4, r4
	mpyf	r1, r4
	addf	r4, r3

	mpyf	r2, r3, r0	; Multiply by the dividend

	ldf	r2, r4
	and	0ffh, r4
	norm	r4, r4
	mpyf	r3, r4
	addf	r4, r0

	ldf	r3, r4
	and	0ffh, r4
	norm 	r4, r4
	mpyf	r2, r4
	bd	ar1
	addf	r4, r0

	popf	r4
	pop	r4
#endif
#endif