aboutsummaryrefslogtreecommitdiff
path: root/gdb/mips-tdep.c
blob: b54b753a07365ee6f444f96a8d67d00b40186efa (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
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
/* Target-dependent code for the MIPS architecture, for GDB, the GNU Debugger.
   Copyright 1988-1999, Free Software Foundation, Inc.
   Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
   and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.

   This file is part of GDB.

   This program 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 of the License, or
   (at your option) any later version.

   This program 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; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "gdb_string.h"
#include "frame.h"
#include "inferior.h"
#include "symtab.h"
#include "value.h"
#include "gdbcmd.h"
#include "language.h"
#include "gdbcore.h"
#include "symfile.h"
#include "objfiles.h"
#include "gdbtypes.h"
#include "target.h"

#include "opcode/mips.h"

struct frame_extra_info
  {
    mips_extra_func_info_t proc_desc;
    int num_args;
  };

/* Some MIPS boards don't support floating point while others only
   support single-precision floating-point operations.  See also
   FP_REGISTER_DOUBLE. */

enum mips_fpu_type
  {
    MIPS_FPU_DOUBLE,		/* Full double precision floating point.  */
    MIPS_FPU_SINGLE,		/* Single precision floating point (R4650).  */
    MIPS_FPU_NONE		/* No floating point.  */
  };

#ifndef MIPS_DEFAULT_FPU_TYPE
#define MIPS_DEFAULT_FPU_TYPE MIPS_FPU_DOUBLE
#endif
static int mips_fpu_type_auto = 1;
static enum mips_fpu_type mips_fpu_type = MIPS_DEFAULT_FPU_TYPE;
#define MIPS_FPU_TYPE mips_fpu_type

#ifndef MIPS_SAVED_REGSIZE
#define MIPS_SAVED_REGSIZE MIPS_REGSIZE
#endif

/* Do not use "TARGET_IS_MIPS64" to test the size of floating point registers */
#ifndef FP_REGISTER_DOUBLE
#define FP_REGISTER_DOUBLE (REGISTER_VIRTUAL_SIZE(FP0_REGNUM) == 8)
#endif


#define VM_MIN_ADDRESS (CORE_ADDR)0x400000

#if 0
static int mips_in_lenient_prologue PARAMS ((CORE_ADDR, CORE_ADDR));
#endif

int gdb_print_insn_mips PARAMS ((bfd_vma, disassemble_info *));

static void mips_print_register PARAMS ((int, int));

static mips_extra_func_info_t
  heuristic_proc_desc PARAMS ((CORE_ADDR, CORE_ADDR, struct frame_info *));

static CORE_ADDR heuristic_proc_start PARAMS ((CORE_ADDR));

static CORE_ADDR read_next_frame_reg PARAMS ((struct frame_info *, int));

int mips_set_processor_type PARAMS ((char *));

static void mips_show_processor_type_command PARAMS ((char *, int));

static void reinit_frame_cache_sfunc PARAMS ((char *, int,
					      struct cmd_list_element *));

static mips_extra_func_info_t
  find_proc_desc PARAMS ((CORE_ADDR pc, struct frame_info * next_frame));

static CORE_ADDR after_prologue PARAMS ((CORE_ADDR pc,
					 mips_extra_func_info_t proc_desc));

/* This value is the model of MIPS in use.  It is derived from the value
   of the PrID register.  */

char *mips_processor_type;

char *tmp_mips_processor_type;

/* A set of original names, to be used when restoring back to generic
   registers from a specific set.  */

char *mips_generic_reg_names[] = MIPS_REGISTER_NAMES;
char **mips_processor_reg_names = mips_generic_reg_names;

char *
mips_register_name (i)
     int i;
{
  return mips_processor_reg_names[i];
}
/* *INDENT-OFF* */
/* Names of IDT R3041 registers.  */

char *mips_r3041_reg_names[] = {
	"zero",	"at",	"v0",	"v1",	"a0",	"a1",	"a2",	"a3",
	"t0",	"t1",	"t2",	"t3",	"t4",	"t5",	"t6",	"t7",
	"s0",	"s1",	"s2",	"s3",	"s4",	"s5",	"s6",	"s7",
	"t8",	"t9",	"k0",	"k1",	"gp",	"sp",	"s8",	"ra",
	"sr",	"lo",	"hi",	"bad",	"cause","pc",
	"f0",   "f1",   "f2",   "f3",   "f4",   "f5",   "f6",   "f7",
	"f8",   "f9",   "f10",  "f11",  "f12",  "f13",  "f14",  "f15",
	"f16",  "f17",  "f18",  "f19",  "f20",  "f21",  "f22",  "f23",
	"f24",  "f25",  "f26",  "f27",  "f28",  "f29",  "f30",  "f31",
	"fsr",  "fir",  "fp",	"",
	"",	"",	"bus",	"ccfg",	"",	"",	"",	"",
	"",	"",	"port",	"cmp",	"",	"",	"epc",	"prid",
};

/* Names of IDT R3051 registers.  */

char *mips_r3051_reg_names[] = {
	"zero",	"at",	"v0",	"v1",	"a0",	"a1",	"a2",	"a3",
	"t0",	"t1",	"t2",	"t3",	"t4",	"t5",	"t6",	"t7",
	"s0",	"s1",	"s2",	"s3",	"s4",	"s5",	"s6",	"s7",
	"t8",	"t9",	"k0",	"k1",	"gp",	"sp",	"s8",	"ra",
	"sr",	"lo",	"hi",	"bad",	"cause","pc",
	"f0",   "f1",   "f2",   "f3",   "f4",   "f5",   "f6",   "f7",
	"f8",   "f9",   "f10",  "f11",  "f12",  "f13",  "f14",  "f15",
	"f16",  "f17",  "f18",  "f19",  "f20",  "f21",  "f22",  "f23",
	"f24",  "f25",  "f26",  "f27",  "f28",  "f29",  "f30",  "f31",
	"fsr",  "fir",  "fp",	"",
	"inx",	"rand",	"elo",	"",	"ctxt",	"",	"",	"",
	"",	"",	"ehi",	"",	"",	"",	"epc",	"prid",
};

/* Names of IDT R3081 registers.  */

char *mips_r3081_reg_names[] = {
	"zero",	"at",	"v0",	"v1",	"a0",	"a1",	"a2",	"a3",
	"t0",	"t1",	"t2",	"t3",	"t4",	"t5",	"t6",	"t7",
	"s0",	"s1",	"s2",	"s3",	"s4",	"s5",	"s6",	"s7",
	"t8",	"t9",	"k0",	"k1",	"gp",	"sp",	"s8",	"ra",
	"sr",	"lo",	"hi",	"bad",	"cause","pc",
	"f0",   "f1",   "f2",   "f3",   "f4",   "f5",   "f6",   "f7",
	"f8",   "f9",   "f10",  "f11",  "f12",  "f13",  "f14",  "f15",
	"f16",  "f17",  "f18",  "f19",  "f20",  "f21",  "f22",  "f23",
	"f24",  "f25",  "f26",  "f27",  "f28",  "f29",  "f30",  "f31",
	"fsr",  "fir",  "fp",	"",
	"inx",	"rand",	"elo",	"cfg",	"ctxt",	"",	"",	"",
	"",	"",	"ehi",	"",	"",	"",	"epc",	"prid",
};

/* Names of LSI 33k registers.  */

char *mips_lsi33k_reg_names[] = {
	"zero",	"at",	"v0",	"v1",	"a0",	"a1",	"a2",	"a3",
	"t0",	"t1",	"t2",	"t3",	"t4",	"t5",	"t6",	"t7",
	"s0",	"s1",	"s2",	"s3",	"s4",	"s5",	"s6",	"s7",
	"t8",	"t9",	"k0",	"k1",	"gp",	"sp",	"s8",	"ra",
	"epc",	"hi",	"lo",	"sr",	"cause","badvaddr",
	"dcic", "bpc",  "bda",  "",     "",     "",     "",      "",
	"",     "",     "",     "",     "",     "",     "",      "",
	"",     "",     "",     "",     "",     "",     "",      "",
	"",     "",     "",     "",     "",     "",     "",      "",
	"",     "",     "",	"",
	"",	"",	"",	"",	"",	"",	"",	 "",
	"",	"",	"",	"",	"",	"",	"",	 "",
};

struct {
  char *name;
  char **regnames;
} mips_processor_type_table[] = {
  { "generic", mips_generic_reg_names },
  { "r3041", mips_r3041_reg_names },
  { "r3051", mips_r3051_reg_names },
  { "r3071", mips_r3081_reg_names },
  { "r3081", mips_r3081_reg_names },
  { "lsi33k", mips_lsi33k_reg_names },
  { NULL, NULL }
};
/* *INDENT-ON* */




/* Table to translate MIPS16 register field to actual register number.  */
static int mips16_to_32_reg[8] =
{16, 17, 2, 3, 4, 5, 6, 7};

/* Heuristic_proc_start may hunt through the text section for a long
   time across a 2400 baud serial line.  Allows the user to limit this
   search.  */

static unsigned int heuristic_fence_post = 0;

#define PROC_LOW_ADDR(proc) ((proc)->pdr.adr)	/* least address */
#define PROC_HIGH_ADDR(proc) ((proc)->high_addr)	/* upper address bound */
#define PROC_FRAME_OFFSET(proc) ((proc)->pdr.frameoffset)
#define PROC_FRAME_REG(proc) ((proc)->pdr.framereg)
#define PROC_FRAME_ADJUST(proc)  ((proc)->frame_adjust)
#define PROC_REG_MASK(proc) ((proc)->pdr.regmask)
#define PROC_FREG_MASK(proc) ((proc)->pdr.fregmask)
#define PROC_REG_OFFSET(proc) ((proc)->pdr.regoffset)
#define PROC_FREG_OFFSET(proc) ((proc)->pdr.fregoffset)
#define PROC_PC_REG(proc) ((proc)->pdr.pcreg)
#define PROC_SYMBOL(proc) (*(struct symbol**)&(proc)->pdr.isym)
#define _PROC_MAGIC_ 0x0F0F0F0F
#define PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym == _PROC_MAGIC_)
#define SET_PROC_DESC_IS_DUMMY(proc) ((proc)->pdr.isym = _PROC_MAGIC_)

struct linked_proc_info
  {
    struct mips_extra_func_info info;
    struct linked_proc_info *next;
  }
 *linked_proc_desc_table = NULL;

void
mips_print_extra_frame_info (fi)
     struct frame_info *fi;
{
  if (fi
      && fi->extra_info
      && fi->extra_info->proc_desc
      && fi->extra_info->proc_desc->pdr.framereg < NUM_REGS)
    printf_filtered (" frame pointer is at %s+%s\n",
		     REGISTER_NAME (fi->extra_info->proc_desc->pdr.framereg),
		     paddr_d (fi->extra_info->proc_desc->pdr.frameoffset));
}

/* Convert between RAW and VIRTUAL registers.  The RAW register size
   defines the remote-gdb packet. */

static int mips64_transfers_32bit_regs_p = 0;

int
mips_register_raw_size (reg_nr)
     int reg_nr;
{
  if (mips64_transfers_32bit_regs_p)
    return REGISTER_VIRTUAL_SIZE (reg_nr);
  else
    return MIPS_REGSIZE;
}

int
mips_register_convertible (reg_nr)
     int reg_nr;
{
  if (mips64_transfers_32bit_regs_p)
    return 0;
  else
    return (REGISTER_RAW_SIZE (reg_nr) > REGISTER_VIRTUAL_SIZE (reg_nr));
}

void
mips_register_convert_to_virtual (n, virtual_type, raw_buf, virt_buf)
     int n;
     struct type *virtual_type;
     char *raw_buf;
     char *virt_buf;
{
  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
    memcpy (virt_buf,
	    raw_buf + (REGISTER_RAW_SIZE (n) - TYPE_LENGTH (virtual_type)),
	    TYPE_LENGTH (virtual_type));
  else
    memcpy (virt_buf,
	    raw_buf,
	    TYPE_LENGTH (virtual_type));
}

void
mips_register_convert_to_raw (virtual_type, n, virt_buf, raw_buf)
     struct type *virtual_type;
     int n;
     char *virt_buf;
     char *raw_buf;
{
  memset (raw_buf, 0, REGISTER_RAW_SIZE (n));
  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
    memcpy (raw_buf + (REGISTER_RAW_SIZE (n) - TYPE_LENGTH (virtual_type)),
	    virt_buf,
	    TYPE_LENGTH (virtual_type));
  else
    memcpy (raw_buf,
	    virt_buf,
	    TYPE_LENGTH (virtual_type));
}

/* Should the upper word of 64-bit addresses be zeroed? */
static int mask_address_p = 1;

/* Should call_function allocate stack space for a struct return?  */
int
mips_use_struct_convention (gcc_p, type)
     int gcc_p;
     struct type *type;
{
  if (MIPS_EABI)
    return (TYPE_LENGTH (type) > 2 * MIPS_SAVED_REGSIZE);
  else
    return 1;			/* Structures are returned by ref in extra arg0 */
}

/* Tell if the program counter value in MEMADDR is in a MIPS16 function.  */

static int
pc_is_mips16 (bfd_vma memaddr)
{
  struct minimal_symbol *sym;

  /* If bit 0 of the address is set, assume this is a MIPS16 address. */
  if (IS_MIPS16_ADDR (memaddr))
    return 1;

  /* A flag indicating that this is a MIPS16 function is stored by elfread.c in
     the high bit of the info field.  Use this to decide if the function is
     MIPS16 or normal MIPS.  */
  sym = lookup_minimal_symbol_by_pc (memaddr);
  if (sym)
    return MSYMBOL_IS_SPECIAL (sym);
  else
    return 0;
}


/* This returns the PC of the first inst after the prologue.  If we can't
   find the prologue, then return 0.  */

static CORE_ADDR
after_prologue (pc, proc_desc)
     CORE_ADDR pc;
     mips_extra_func_info_t proc_desc;
{
  struct symtab_and_line sal;
  CORE_ADDR func_addr, func_end;

  if (!proc_desc)
    proc_desc = find_proc_desc (pc, NULL);

  if (proc_desc)
    {
      /* If function is frameless, then we need to do it the hard way.  I
         strongly suspect that frameless always means prologueless... */
      if (PROC_FRAME_REG (proc_desc) == SP_REGNUM
	  && PROC_FRAME_OFFSET (proc_desc) == 0)
	return 0;
    }

  if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end))
    return 0;			/* Unknown */

  sal = find_pc_line (func_addr, 0);

  if (sal.end < func_end)
    return sal.end;

  /* The line after the prologue is after the end of the function.  In this
     case, tell the caller to find the prologue the hard way.  */

  return 0;
}

/* Decode a MIPS32 instruction that saves a register in the stack, and
   set the appropriate bit in the general register mask or float register mask
   to indicate which register is saved.  This is a helper function
   for mips_find_saved_regs.  */

static void
mips32_decode_reg_save (inst, gen_mask, float_mask)
     t_inst inst;
     unsigned long *gen_mask;
     unsigned long *float_mask;
{
  int reg;

  if ((inst & 0xffe00000) == 0xafa00000		/* sw reg,n($sp) */
      || (inst & 0xffe00000) == 0xafc00000	/* sw reg,n($r30) */
      || (inst & 0xffe00000) == 0xffa00000)	/* sd reg,n($sp) */
    {
      /* It might be possible to use the instruction to
         find the offset, rather than the code below which
         is based on things being in a certain order in the
         frame, but figuring out what the instruction's offset
         is relative to might be a little tricky.  */
      reg = (inst & 0x001f0000) >> 16;
      *gen_mask |= (1 << reg);
    }
  else if ((inst & 0xffe00000) == 0xe7a00000	/* swc1 freg,n($sp) */
	   || (inst & 0xffe00000) == 0xe7c00000		/* swc1 freg,n($r30) */
	   || (inst & 0xffe00000) == 0xf7a00000)	/* sdc1 freg,n($sp) */

    {
      reg = ((inst & 0x001f0000) >> 16);
      *float_mask |= (1 << reg);
    }
}

/* Decode a MIPS16 instruction that saves a register in the stack, and
   set the appropriate bit in the general register or float register mask
   to indicate which register is saved.  This is a helper function
   for mips_find_saved_regs.  */

static void
mips16_decode_reg_save (inst, gen_mask)
     t_inst inst;
     unsigned long *gen_mask;
{
  if ((inst & 0xf800) == 0xd000)	/* sw reg,n($sp) */
    {
      int reg = mips16_to_32_reg[(inst & 0x700) >> 8];
      *gen_mask |= (1 << reg);
    }
  else if ((inst & 0xff00) == 0xf900)	/* sd reg,n($sp) */
    {
      int reg = mips16_to_32_reg[(inst & 0xe0) >> 5];
      *gen_mask |= (1 << reg);
    }
  else if ((inst & 0xff00) == 0x6200	/* sw $ra,n($sp) */
	   || (inst & 0xff00) == 0xfa00)	/* sd $ra,n($sp) */
    *gen_mask |= (1 << RA_REGNUM);
}


/* Fetch and return instruction from the specified location.  If the PC
   is odd, assume it's a MIPS16 instruction; otherwise MIPS32.  */

static t_inst
mips_fetch_instruction (addr)
     CORE_ADDR addr;
{
  char buf[MIPS_INSTLEN];
  int instlen;
  int status;

  if (pc_is_mips16 (addr))
    {
      instlen = MIPS16_INSTLEN;
      addr = UNMAKE_MIPS16_ADDR (addr);
    }
  else
    instlen = MIPS_INSTLEN;
  status = read_memory_nobpt (addr, buf, instlen);
  if (status)
    memory_error (status, addr);
  return extract_unsigned_integer (buf, instlen);
}


/* These the fields of 32 bit mips instructions */
#define mips32_op(x) (x >> 25)
#define itype_op(x) (x >> 25)
#define itype_rs(x) ((x >> 21)& 0x1f)
#define itype_rt(x) ((x >> 16) & 0x1f)
#define itype_immediate(x) ( x & 0xffff)

#define jtype_op(x) (x >> 25)
#define jtype_target(x) ( x & 0x03fffff)

#define rtype_op(x) (x >>25)
#define rtype_rs(x) ((x>>21) & 0x1f)
#define rtype_rt(x) ((x>>16)  & 0x1f)
#define rtype_rd(x) ((x>>11) & 0x1f)
#define rtype_shamt(x) ((x>>6) & 0x1f)
#define rtype_funct(x) (x & 0x3f )

static CORE_ADDR
mips32_relative_offset (unsigned long inst)
{
  long x;
  x = itype_immediate (inst);
  if (x & 0x8000)		/* sign bit set */
    {
      x |= 0xffff0000;		/* sign extension */
    }
  x = x << 2;
  return x;
}

/* Determine whate to set a single step breakpoint while considering
   branch prediction */
CORE_ADDR
mips32_next_pc (CORE_ADDR pc)
{
  unsigned long inst;
  int op;
  inst = mips_fetch_instruction (pc);
  if ((inst & 0xe0000000) != 0)	/* Not a special, junp or branch instruction */
    {
      if ((inst >> 27) == 5)	/* BEQL BNEZ BLEZL BGTZE , bits 0101xx */
	{
	  op = ((inst >> 25) & 0x03);
	  switch (op)
	    {
	    case 0:
	      goto equal_branch;	/* BEQL   */
	    case 1:
	      goto neq_branch;	/* BNEZ   */
	    case 2:
	      goto less_branch;	/* BLEZ   */
	    case 3:
	      goto greater_branch;	/* BGTZ */
	    default:
	      pc += 4;
	    }
	}
      else
	pc += 4;		/* Not a branch, next instruction is easy */
    }
  else
    {				/* This gets way messy */

      /* Further subdivide into SPECIAL, REGIMM and other */
      switch (op = ((inst >> 26) & 0x07))	/* extract bits 28,27,26 */
	{
	case 0:		/* SPECIAL */
	  op = rtype_funct (inst);
	  switch (op)
	    {
	    case 8:		/* JR */
	    case 9:		/* JALR */
	      pc = read_register (rtype_rs (inst));	/* Set PC to that address */
	      break;
	    default:
	      pc += 4;
	    }

	  break;		/* end special */
	case 1:		/* REGIMM */
	  {
	    op = jtype_op (inst);	/* branch condition */
	    switch (jtype_op (inst))
	      {
	      case 0:		/* BLTZ */
	      case 2:		/* BLTXL */
	      case 16:		/* BLTZALL */
	      case 18:		/* BLTZALL */
	      less_branch:
		if (read_register (itype_rs (inst)) < 0)
		  pc += mips32_relative_offset (inst) + 4;
		else
		  pc += 8;	/* after the delay slot */
		break;
	      case 1:		/* GEZ */
	      case 3:		/* BGEZL */
	      case 17:		/* BGEZAL */
	      case 19:		/* BGEZALL */
	      greater_equal_branch:
		if (read_register (itype_rs (inst)) >= 0)
		  pc += mips32_relative_offset (inst) + 4;
		else
		  pc += 8;	/* after the delay slot */
		break;
		/* All of the other intructions in the REGIMM catagory */
	      default:
		pc += 4;
	      }
	  }
	  break;		/* end REGIMM */
	case 2:		/* J */
	case 3:		/* JAL */
	  {
	    unsigned long reg;
	    reg = jtype_target (inst) << 2;
	    pc = reg + ((pc + 4) & 0xf0000000);
	    /* Whats this mysterious 0xf000000 adjustment ??? */
	  }
	  break;
	  /* FIXME case JALX : */
	  {
	    unsigned long reg;
	    reg = jtype_target (inst) << 2;
	    pc = reg + ((pc + 4) & 0xf0000000) + 1;	/* yes, +1 */
	    /* Add 1 to indicate 16 bit mode - Invert ISA mode */
	  }
	  break;		/* The new PC will be alternate mode */
	case 4:		/* BEQ , BEQL */
	equal_branch:
	  if (read_register (itype_rs (inst)) ==
	      read_register (itype_rt (inst)))
	    pc += mips32_relative_offset (inst) + 4;
	  else
	    pc += 8;
	  break;
	case 5:		/* BNE , BNEL */
	neq_branch:
	  if (read_register (itype_rs (inst)) !=
	      read_register (itype_rs (inst)))
	    pc += mips32_relative_offset (inst) + 4;
	  else
	    pc += 8;
	  break;
	case 6:		/* BLEZ , BLEZL */
	less_zero_branch:
	  if (read_register (itype_rs (inst) <= 0))
	    pc += mips32_relative_offset (inst) + 4;
	  else
	    pc += 8;
	  break;
	case 7:
	greater_branch:	/* BGTZ BGTZL */
	  if (read_register (itype_rs (inst) > 0))
	    pc += mips32_relative_offset (inst) + 4;
	  else
	    pc += 8;
	  break;
	default:
	  pc += 8;
	}			/* switch */
    }				/* else */
  return pc;
}				/* mips32_next_pc */

/* Decoding the next place to set a breakpoint is irregular for the
   mips 16 variant, but fortunatly, there fewer instructions. We have to cope
   ith extensions for 16 bit instructions and a pair of actual 32 bit instructions.
   We dont want to set a single step instruction on the extend instruction
   either.
 */

/* Lots of mips16 instruction formats */
/* Predicting jumps requires itype,ritype,i8type
   and their extensions      extItype,extritype,extI8type
 */
enum mips16_inst_fmts
{
  itype,			/* 0  immediate 5,10 */
  ritype,			/* 1   5,3,8 */
  rrtype,			/* 2   5,3,3,5 */
  rritype,			/* 3   5,3,3,5 */
  rrrtype,			/* 4   5,3,3,3,2 */
  rriatype,			/* 5   5,3,3,1,4 */
  shifttype,			/* 6   5,3,3,3,2 */
  i8type,			/* 7   5,3,8 */
  i8movtype,			/* 8   5,3,3,5 */
  i8mov32rtype,			/* 9   5,3,5,3 */
  i64type,			/* 10  5,3,8 */
  ri64type,			/* 11  5,3,3,5 */
  jalxtype,			/* 12  5,1,5,5,16 - a 32 bit instruction */
  exiItype,			/* 13  5,6,5,5,1,1,1,1,1,1,5 */
  extRitype,			/* 14  5,6,5,5,3,1,1,1,5 */
  extRRItype,			/* 15  5,5,5,5,3,3,5 */
  extRRIAtype,			/* 16  5,7,4,5,3,3,1,4 */
  EXTshifttype,			/* 17  5,5,1,1,1,1,1,1,5,3,3,1,1,1,2 */
  extI8type,			/* 18  5,6,5,5,3,1,1,1,5 */
  extI64type,			/* 19  5,6,5,5,3,1,1,1,5 */
  extRi64type,			/* 20  5,6,5,5,3,3,5 */
  extshift64type		/* 21  5,5,1,1,1,1,1,1,5,1,1,1,3,5 */
};
/* I am heaping all the fields of the formats into one structure and then,
   only the fields which are involved in instruction extension */
struct upk_mips16
  {
    unsigned short inst;
    enum mips16_inst_fmts fmt;
    unsigned long offset;
    unsigned int regx;		/* Function in i8 type */
    unsigned int regy;
  };



static void
print_unpack (char *comment,
	      struct upk_mips16 *u)
{
  printf ("%s %04x ,f(%d) off(%s) (x(%x) y(%x)\n",
	  comment, u->inst, u->fmt, paddr (u->offset), u->regx, u->regy);
}

/* The EXT-I, EXT-ri nad EXT-I8 instructions all have the same
   format for the bits which make up the immediatate extension.
 */
static unsigned long
extended_offset (unsigned long extension)
{
  unsigned long value;
  value = (extension >> 21) & 0x3f;	/* * extract 15:11 */
  value = value << 6;
  value |= (extension >> 16) & 0x1f;	/* extrace 10:5 */
  value = value << 5;
  value |= extension & 0x01f;	/* extract 4:0 */
  return value;
}

/* Only call this function if you know that this is an extendable
   instruction, It wont malfunction, but why make excess remote memory references?
   If the immediate operands get sign extended or somthing, do it after
   the extension is performed.
 */
/* FIXME: Every one of these cases needs to worry about sign extension
   when the offset is to be used in relative addressing */


static unsigned short
fetch_mips_16 (CORE_ADDR pc)
{
  char buf[8];
  pc &= 0xfffffffe;		/* clear the low order bit */
  target_read_memory (pc, buf, 2);
  return extract_unsigned_integer (buf, 2);
}

static void
unpack_mips16 (CORE_ADDR pc,
	       struct upk_mips16 *upk)
{
  CORE_ADDR extpc;
  unsigned long extension;
  int extended;
  extpc = (pc - 4) & ~0x01;	/* Extensions are 32 bit instructions */
  /* Decrement to previous address and loose the 16bit mode flag */
  /* return if the instruction was extendable, but not actually extended */
  extended = ((mips32_op (extension) == 30) ? 1 : 0);
  if (extended)
    {
      extension = mips_fetch_instruction (extpc);
    }
  switch (upk->fmt)
    {
    case itype:
      {
	unsigned long value;
	if (extended)
	  {
	    value = extended_offset (extension);
	    value = value << 11;	/* rom for the original value */
	    value |= upk->inst & 0x7ff;		/* eleven bits from instruction */
	  }
	else
	  {
	    value = upk->inst & 0x7ff;
	    /* FIXME : Consider sign extension */
	  }
	upk->offset = value;
      }
      break;
    case ritype:
    case i8type:
      {				/* A register identifier and an offset */
	/* Most of the fields are the same as I type but the
	   immediate value is of a different length */
	unsigned long value;
	if (extended)
	  {
	    value = extended_offset (extension);
	    value = value << 8;	/* from the original instruction */
	    value |= upk->inst & 0xff;	/* eleven bits from instruction */
	    upk->regx = (extension >> 8) & 0x07;	/* or i8 funct */
	    if (value & 0x4000)	/* test the sign bit , bit 26 */
	      {
		value &= ~0x3fff;	/* remove the sign bit */
		value = -value;
	      }
	  }
	else
	  {
	    value = upk->inst & 0xff;	/* 8 bits */
	    upk->regx = (upk->inst >> 8) & 0x07;	/* or i8 funct */
	    /* FIXME: Do sign extension , this format needs it */
	    if (value & 0x80)	/* THIS CONFUSES ME */
	      {
		value &= 0xef;	/* remove the sign bit */
		value = -value;
	      }

	  }
	upk->offset = value;
	break;
      }
    case jalxtype:
      {
	unsigned long value;
	unsigned short nexthalf;
	value = ((upk->inst & 0x1f) << 5) | ((upk->inst >> 5) & 0x1f);
	value = value << 16;
	nexthalf = mips_fetch_instruction (pc + 2);	/* low bit still set */
	value |= nexthalf;
	upk->offset = value;
	break;
      }
    default:
      printf_filtered ("Decoding unimplemented instruction format type\n");
      break;
    }
  /* print_unpack("UPK",upk) ; */
}


#define mips16_op(x) (x >> 11)

/* This is a map of the opcodes which ae known to perform branches */
static unsigned char map16[32] =
{0, 0, 1, 1, 1, 1, 0, 0,
 0, 0, 0, 0, 1, 0, 0, 0,
 0, 0, 0, 0, 0, 0, 0, 0,
 0, 0, 0, 0, 0, 1, 1, 0
};

static CORE_ADDR
add_offset_16 (CORE_ADDR pc, int offset)
{
  return ((offset << 2) | ((pc + 2) & (0xf0000000)));

}



static struct upk_mips16 upk;

CORE_ADDR
mips16_next_pc (CORE_ADDR pc)
{
  int op;
  t_inst inst;
  /* inst = mips_fetch_instruction(pc) ; - This doesnt always work */
  inst = fetch_mips_16 (pc);
  upk.inst = inst;
  op = mips16_op (upk.inst);
  if (map16[op])
    {
      int reg;
      switch (op)
	{
	case 2:		/* Branch */
	  upk.fmt = itype;
	  unpack_mips16 (pc, &upk);
	  {
	    long offset;
	    offset = upk.offset;
	    if (offset & 0x800)
	      {
		offset &= 0xeff;
		offset = -offset;
	      }
	    pc += (offset << 1) + 2;
	  }
	  break;
	case 3:		/* JAL , JALX - Watch out, these are 32 bit instruction */
	  upk.fmt = jalxtype;
	  unpack_mips16 (pc, &upk);
	  pc = add_offset_16 (pc, upk.offset);
	  if ((upk.inst >> 10) & 0x01)	/* Exchange mode */
	    pc = pc & ~0x01;	/* Clear low bit, indicate 32 bit mode */
	  else
	    pc |= 0x01;
	  break;
	case 4:		/* beqz */
	  upk.fmt = ritype;
	  unpack_mips16 (pc, &upk);
	  reg = read_register (upk.regx);
	  if (reg == 0)
	    pc += (upk.offset << 1) + 2;
	  else
	    pc += 2;
	  break;
	case 5:		/* bnez */
	  upk.fmt = ritype;
	  unpack_mips16 (pc, &upk);
	  reg = read_register (upk.regx);
	  if (reg != 0)
	    pc += (upk.offset << 1) + 2;
	  else
	    pc += 2;
	  break;
	case 12:		/* I8 Formats btez btnez */
	  upk.fmt = i8type;
	  unpack_mips16 (pc, &upk);
	  /* upk.regx contains the opcode */
	  reg = read_register (24);	/* Test register is 24 */
	  if (((upk.regx == 0) && (reg == 0))	/* BTEZ */
	      || ((upk.regx == 1) && (reg != 0)))	/* BTNEZ */
	    /* pc = add_offset_16(pc,upk.offset) ; */
	    pc += (upk.offset << 1) + 2;
	  else
	    pc += 2;
	  break;
	case 29:		/* RR Formats JR, JALR, JALR-RA */
	  upk.fmt = rrtype;
	  op = upk.inst & 0x1f;
	  if (op == 0)
	    {
	      upk.regx = (upk.inst >> 8) & 0x07;
	      upk.regy = (upk.inst >> 5) & 0x07;
	      switch (upk.regy)
		{
		case 0:
		  reg = upk.regx;
		  break;
		case 1:
		  reg = 31;
		  break;	/* Function return instruction */
		case 2:
		  reg = upk.regx;
		  break;
		default:
		  reg = 31;
		  break;	/* BOGUS Guess */
		}
	      pc = read_register (reg);
	    }
	  else
	    pc += 2;
	  break;
	case 30:		/* This is an extend instruction */
	  pc += 4;		/* Dont be setting breakpints on the second half */
	  break;
	default:
	  printf ("Filtered - next PC probably incorrrect due to jump inst\n");
	  pc += 2;
	  break;
	}
    }
  else
    pc += 2;			/* just a good old instruction */
  /* See if we CAN actually break on the next instruction */
  /* printf("NXTm16PC %08x\n",(unsigned long)pc) ; */
  return pc;
}				/* mips16_next_pc */

/* The mips_next_pc function supports single_tep when the remote target monitor or
   stub is not developed enough to so a single_step.
   It works by decoding the current instruction and predicting where a branch
   will go. This isnt hard because all the data is available.
   The MIPS32 and MIPS16 variants are quite different
 */
CORE_ADDR
mips_next_pc (CORE_ADDR pc)
{
  t_inst inst;
  /* inst = mips_fetch_instruction(pc) ; */
  /* if (pc_is_mips16) <----- This is failing */
  if (pc & 0x01)
    return mips16_next_pc (pc);
  else
    return mips32_next_pc (pc);
}				/* mips_next_pc */

/* Guaranteed to set fci->saved_regs to some values (it never leaves it
   NULL).  */

void
mips_find_saved_regs (fci)
     struct frame_info *fci;
{
  int ireg;
  CORE_ADDR reg_position;
  /* r0 bit means kernel trap */
  int kernel_trap;
  /* What registers have been saved?  Bitmasks.  */
  unsigned long gen_mask, float_mask;
  mips_extra_func_info_t proc_desc;
  t_inst inst;

  frame_saved_regs_zalloc (fci);

  /* If it is the frame for sigtramp, the saved registers are located
     in a sigcontext structure somewhere on the stack.
     If the stack layout for sigtramp changes we might have to change these
     constants and the companion fixup_sigtramp in mdebugread.c  */
#ifndef SIGFRAME_BASE
/* To satisfy alignment restrictions, sigcontext is located 4 bytes
   above the sigtramp frame.  */
#define SIGFRAME_BASE		MIPS_REGSIZE
/* FIXME!  Are these correct?? */
#define SIGFRAME_PC_OFF		(SIGFRAME_BASE + 2 * MIPS_REGSIZE)
#define SIGFRAME_REGSAVE_OFF	(SIGFRAME_BASE + 3 * MIPS_REGSIZE)
#define SIGFRAME_FPREGSAVE_OFF	\
        (SIGFRAME_REGSAVE_OFF + MIPS_NUMREGS * MIPS_REGSIZE + 3 * MIPS_REGSIZE)
#endif
#ifndef SIGFRAME_REG_SIZE
/* FIXME!  Is this correct?? */
#define SIGFRAME_REG_SIZE	MIPS_REGSIZE
#endif
  if (fci->signal_handler_caller)
    {
      for (ireg = 0; ireg < MIPS_NUMREGS; ireg++)
	{
	  reg_position = fci->frame + SIGFRAME_REGSAVE_OFF
	    + ireg * SIGFRAME_REG_SIZE;
	  fci->saved_regs[ireg] = reg_position;
	}
      for (ireg = 0; ireg < MIPS_NUMREGS; ireg++)
	{
	  reg_position = fci->frame + SIGFRAME_FPREGSAVE_OFF
	    + ireg * SIGFRAME_REG_SIZE;
	  fci->saved_regs[FP0_REGNUM + ireg] = reg_position;
	}
      fci->saved_regs[PC_REGNUM] = fci->frame + SIGFRAME_PC_OFF;
      return;
    }

  proc_desc = fci->extra_info->proc_desc;
  if (proc_desc == NULL)
    /* I'm not sure how/whether this can happen.  Normally when we can't
       find a proc_desc, we "synthesize" one using heuristic_proc_desc
       and set the saved_regs right away.  */
    return;

  kernel_trap = PROC_REG_MASK (proc_desc) & 1;
  gen_mask = kernel_trap ? 0xFFFFFFFF : PROC_REG_MASK (proc_desc);
  float_mask = kernel_trap ? 0xFFFFFFFF : PROC_FREG_MASK (proc_desc);

  if (				/* In any frame other than the innermost or a frame interrupted by
				   a signal, we assume that all registers have been saved.
				   This assumes that all register saves in a function happen before
				   the first function call.  */
       (fci->next == NULL || fci->next->signal_handler_caller)

  /* In a dummy frame we know exactly where things are saved.  */
       && !PROC_DESC_IS_DUMMY (proc_desc)

  /* Don't bother unless we are inside a function prologue.  Outside the
     prologue, we know where everything is. */

       && in_prologue (fci->pc, PROC_LOW_ADDR (proc_desc))

  /* Not sure exactly what kernel_trap means, but if it means
     the kernel saves the registers without a prologue doing it,
     we better not examine the prologue to see whether registers
     have been saved yet.  */
       && !kernel_trap)
    {
      /* We need to figure out whether the registers that the proc_desc
         claims are saved have been saved yet.  */

      CORE_ADDR addr;

      /* Bitmasks; set if we have found a save for the register.  */
      unsigned long gen_save_found = 0;
      unsigned long float_save_found = 0;
      int instlen;

      /* If the address is odd, assume this is MIPS16 code.  */
      addr = PROC_LOW_ADDR (proc_desc);
      instlen = pc_is_mips16 (addr) ? MIPS16_INSTLEN : MIPS_INSTLEN;

      /* Scan through this function's instructions preceding the current
         PC, and look for those that save registers.  */
      while (addr < fci->pc)
	{
	  inst = mips_fetch_instruction (addr);
	  if (pc_is_mips16 (addr))
	    mips16_decode_reg_save (inst, &gen_save_found);
	  else
	    mips32_decode_reg_save (inst, &gen_save_found, &float_save_found);
	  addr += instlen;
	}
      gen_mask = gen_save_found;
      float_mask = float_save_found;
    }

  /* Fill in the offsets for the registers which gen_mask says
     were saved.  */
  reg_position = fci->frame + PROC_REG_OFFSET (proc_desc);
  for (ireg = MIPS_NUMREGS - 1; gen_mask; --ireg, gen_mask <<= 1)
    if (gen_mask & 0x80000000)
      {
	fci->saved_regs[ireg] = reg_position;
	reg_position -= MIPS_SAVED_REGSIZE;
      }

  /* The MIPS16 entry instruction saves $s0 and $s1 in the reverse order
     of that normally used by gcc.  Therefore, we have to fetch the first
     instruction of the function, and if it's an entry instruction that
     saves $s0 or $s1, correct their saved addresses.  */
  if (pc_is_mips16 (PROC_LOW_ADDR (proc_desc)))
    {
      inst = mips_fetch_instruction (PROC_LOW_ADDR (proc_desc));
      if ((inst & 0xf81f) == 0xe809 && (inst & 0x700) != 0x700)		/* entry */
	{
	  int reg;
	  int sreg_count = (inst >> 6) & 3;

	  /* Check if the ra register was pushed on the stack.  */
	  reg_position = fci->frame + PROC_REG_OFFSET (proc_desc);
	  if (inst & 0x20)
	    reg_position -= MIPS_SAVED_REGSIZE;

	  /* Check if the s0 and s1 registers were pushed on the stack.  */
	  for (reg = 16; reg < sreg_count + 16; reg++)
	    {
	      fci->saved_regs[reg] = reg_position;
	      reg_position -= MIPS_SAVED_REGSIZE;
	    }
	}
    }

  /* Fill in the offsets for the registers which float_mask says
     were saved.  */
  reg_position = fci->frame + PROC_FREG_OFFSET (proc_desc);

  /* The freg_offset points to where the first *double* register
     is saved.  So skip to the high-order word. */
  if (!GDB_TARGET_IS_MIPS64)
    reg_position += MIPS_SAVED_REGSIZE;

  /* Fill in the offsets for the float registers which float_mask says
     were saved.  */
  for (ireg = MIPS_NUMREGS - 1; float_mask; --ireg, float_mask <<= 1)
    if (float_mask & 0x80000000)
      {
	fci->saved_regs[FP0_REGNUM + ireg] = reg_position;
	reg_position -= MIPS_SAVED_REGSIZE;
      }

  fci->saved_regs[PC_REGNUM] = fci->saved_regs[RA_REGNUM];
}

static CORE_ADDR
read_next_frame_reg (fi, regno)
     struct frame_info *fi;
     int regno;
{
  for (; fi; fi = fi->next)
    {
      /* We have to get the saved sp from the sigcontext
         if it is a signal handler frame.  */
      if (regno == SP_REGNUM && !fi->signal_handler_caller)
	return fi->frame;
      else
	{
	  if (fi->saved_regs == NULL)
	    mips_find_saved_regs (fi);
	  if (fi->saved_regs[regno])
	    return read_memory_integer (fi->saved_regs[regno], MIPS_SAVED_REGSIZE);
	}
    }
  return read_register (regno);
}

/* mips_addr_bits_remove - remove useless address bits  */

CORE_ADDR
mips_addr_bits_remove (addr)
     CORE_ADDR addr;
{
#if GDB_TARGET_IS_MIPS64
  if (mask_address_p && (addr >> 32 == (CORE_ADDR) 0xffffffff))
    {
      /* This hack is a work-around for existing boards using PMON,
         the simulator, and any other 64-bit targets that doesn't have
         true 64-bit addressing.  On these targets, the upper 32 bits
         of addresses are ignored by the hardware.  Thus, the PC or SP
         are likely to have been sign extended to all 1s by instruction
         sequences that load 32-bit addresses.  For example, a typical
         piece of code that loads an address is this:
         lui $r2, <upper 16 bits>
         ori $r2, <lower 16 bits>
         But the lui sign-extends the value such that the upper 32 bits
         may be all 1s.  The workaround is simply to mask off these bits.
         In the future, gcc may be changed to support true 64-bit
         addressing, and this masking will have to be disabled.  */
      addr &= (CORE_ADDR) 0xffffffff;
    }
#else
  /* Even when GDB is configured for some 32-bit targets (e.g. mips-elf),
     BFD is configured to handle 64-bit targets, so CORE_ADDR is 64 bits.
     So we still have to mask off useless bits from addresses.  */
  addr &= (CORE_ADDR) 0xffffffff;
#endif

  return addr;
}

void
mips_init_frame_pc_first (fromleaf, prev)
     int fromleaf;
     struct frame_info *prev;
{
  CORE_ADDR pc, tmp;

  pc = ((fromleaf) ? SAVED_PC_AFTER_CALL (prev->next) :
	prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
  tmp = mips_skip_stub (pc);
  prev->pc = tmp ? tmp : pc;
}


CORE_ADDR
mips_frame_saved_pc (frame)
     struct frame_info *frame;
{
  CORE_ADDR saved_pc;
  mips_extra_func_info_t proc_desc = frame->extra_info->proc_desc;
  /* We have to get the saved pc from the sigcontext
     if it is a signal handler frame.  */
  int pcreg = frame->signal_handler_caller ? PC_REGNUM
  : (proc_desc ? PROC_PC_REG (proc_desc) : RA_REGNUM);

  if (proc_desc && PROC_DESC_IS_DUMMY (proc_desc))
    saved_pc = read_memory_integer (frame->frame - MIPS_SAVED_REGSIZE, MIPS_SAVED_REGSIZE);
  else
    saved_pc = read_next_frame_reg (frame, pcreg);

  return ADDR_BITS_REMOVE (saved_pc);
}

static struct mips_extra_func_info temp_proc_desc;
static CORE_ADDR temp_saved_regs[NUM_REGS];

/* Set a register's saved stack address in temp_saved_regs.  If an address
   has already been set for this register, do nothing; this way we will
   only recognize the first save of a given register in a function prologue.
   This is a helper function for mips{16,32}_heuristic_proc_desc.  */

static void
set_reg_offset (regno, offset)
     int regno;
     CORE_ADDR offset;
{
  if (temp_saved_regs[regno] == 0)
    temp_saved_regs[regno] = offset;
}


/* Test whether the PC points to the return instruction at the
   end of a function. */

static int
mips_about_to_return (pc)
     CORE_ADDR pc;
{
  if (pc_is_mips16 (pc))
    /* This mips16 case isn't necessarily reliable.  Sometimes the compiler
       generates a "jr $ra"; other times it generates code to load
       the return address from the stack to an accessible register (such
       as $a3), then a "jr" using that register.  This second case
       is almost impossible to distinguish from an indirect jump
       used for switch statements, so we don't even try.  */
    return mips_fetch_instruction (pc) == 0xe820;	/* jr $ra */
  else
    return mips_fetch_instruction (pc) == 0x3e00008;	/* jr $ra */
}


/* This fencepost looks highly suspicious to me.  Removing it also
   seems suspicious as it could affect remote debugging across serial
   lines.  */

static CORE_ADDR
heuristic_proc_start (pc)
     CORE_ADDR pc;
{
  CORE_ADDR start_pc;
  CORE_ADDR fence;
  int instlen;
  int seen_adjsp = 0;

  pc = ADDR_BITS_REMOVE (pc);
  start_pc = pc;
  fence = start_pc - heuristic_fence_post;
  if (start_pc == 0)
    return 0;

  if (heuristic_fence_post == UINT_MAX
      || fence < VM_MIN_ADDRESS)
    fence = VM_MIN_ADDRESS;

  instlen = pc_is_mips16 (pc) ? MIPS16_INSTLEN : MIPS_INSTLEN;

  /* search back for previous return */
  for (start_pc -= instlen;; start_pc -= instlen)
    if (start_pc < fence)
      {
	/* It's not clear to me why we reach this point when
	   stop_soon_quietly, but with this test, at least we
	   don't print out warnings for every child forked (eg, on
	   decstation).  22apr93 rich@cygnus.com.  */
	if (!stop_soon_quietly)
	  {
	    static int blurb_printed = 0;

	    warning ("Warning: GDB can't find the start of the function at 0x%s.",
		     paddr_nz (pc));

	    if (!blurb_printed)
	      {
		/* This actually happens frequently in embedded
		   development, when you first connect to a board
		   and your stack pointer and pc are nowhere in
		   particular.  This message needs to give people
		   in that situation enough information to
		   determine that it's no big deal.  */
		printf_filtered ("\n\
    GDB is unable to find the start of the function at 0x%s\n\
and thus can't determine the size of that function's stack frame.\n\
This means that GDB may be unable to access that stack frame, or\n\
the frames below it.\n\
    This problem is most likely caused by an invalid program counter or\n\
stack pointer.\n\
    However, if you think GDB should simply search farther back\n\
from 0x%s for code which looks like the beginning of a\n\
function, you can increase the range of the search using the `set\n\
heuristic-fence-post' command.\n",
				 paddr_nz (pc), paddr_nz (pc));
		blurb_printed = 1;
	      }
	  }

	return 0;
      }
    else if (pc_is_mips16 (start_pc))
      {
	unsigned short inst;

	/* On MIPS16, any one of the following is likely to be the
	   start of a function:
	   entry
	   addiu sp,-n
	   daddiu sp,-n
	   extend -n followed by 'addiu sp,+n' or 'daddiu sp,+n'  */
	inst = mips_fetch_instruction (start_pc);
	if (((inst & 0xf81f) == 0xe809 && (inst & 0x700) != 0x700)	/* entry */
	    || (inst & 0xff80) == 0x6380	/* addiu sp,-n */
	    || (inst & 0xff80) == 0xfb80	/* daddiu sp,-n */
	    || ((inst & 0xf810) == 0xf010 && seen_adjsp))	/* extend -n */
	  break;
	else if ((inst & 0xff00) == 0x6300	/* addiu sp */
		 || (inst & 0xff00) == 0xfb00)	/* daddiu sp */
	  seen_adjsp = 1;
	else
	  seen_adjsp = 0;
      }
    else if (mips_about_to_return (start_pc))
      {
	start_pc += 2 * MIPS_INSTLEN;	/* skip return, and its delay slot */
	break;
      }

#if 0
  /* skip nops (usually 1) 0 - is this */
  while (start_pc < pc && read_memory_integer (start_pc, MIPS_INSTLEN) == 0)
    start_pc += MIPS_INSTLEN;
#endif
  return start_pc;
}

/* Fetch the immediate value from a MIPS16 instruction.
   If the previous instruction was an EXTEND, use it to extend
   the upper bits of the immediate value.  This is a helper function
   for mips16_heuristic_proc_desc.  */

static int
mips16_get_imm (prev_inst, inst, nbits, scale, is_signed)
     unsigned short prev_inst;	/* previous instruction */
     unsigned short inst;	/* current instruction */
     int nbits;			/* number of bits in imm field */
     int scale;			/* scale factor to be applied to imm */
     int is_signed;		/* is the imm field signed? */
{
  int offset;

  if ((prev_inst & 0xf800) == 0xf000)	/* prev instruction was EXTEND? */
    {
      offset = ((prev_inst & 0x1f) << 11) | (prev_inst & 0x7e0);
      if (offset & 0x8000)	/* check for negative extend */
	offset = 0 - (0x10000 - (offset & 0xffff));
      return offset | (inst & 0x1f);
    }
  else
    {
      int max_imm = 1 << nbits;
      int mask = max_imm - 1;
      int sign_bit = max_imm >> 1;

      offset = inst & mask;
      if (is_signed && (offset & sign_bit))
	offset = 0 - (max_imm - offset);
      return offset * scale;
    }
}


/* Fill in values in temp_proc_desc based on the MIPS16 instruction
   stream from start_pc to limit_pc.  */

static void
mips16_heuristic_proc_desc (start_pc, limit_pc, next_frame, sp)
     CORE_ADDR start_pc, limit_pc;
     struct frame_info *next_frame;
     CORE_ADDR sp;
{
  CORE_ADDR cur_pc;
  CORE_ADDR frame_addr = 0;	/* Value of $r17, used as frame pointer */
  unsigned short prev_inst = 0;	/* saved copy of previous instruction */
  unsigned inst = 0;		/* current instruction */
  unsigned entry_inst = 0;	/* the entry instruction */
  int reg, offset;

  PROC_FRAME_OFFSET (&temp_proc_desc) = 0;	/* size of stack frame */
  PROC_FRAME_ADJUST (&temp_proc_desc) = 0;	/* offset of FP from SP */

  for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += MIPS16_INSTLEN)
    {
      /* Save the previous instruction.  If it's an EXTEND, we'll extract
         the immediate offset extension from it in mips16_get_imm.  */
      prev_inst = inst;

      /* Fetch and decode the instruction.   */
      inst = (unsigned short) mips_fetch_instruction (cur_pc);
      if ((inst & 0xff00) == 0x6300	/* addiu sp */
	  || (inst & 0xff00) == 0xfb00)		/* daddiu sp */
	{
	  offset = mips16_get_imm (prev_inst, inst, 8, 8, 1);
	  if (offset < 0)	/* negative stack adjustment? */
	    PROC_FRAME_OFFSET (&temp_proc_desc) -= offset;
	  else
	    /* Exit loop if a positive stack adjustment is found, which
	       usually means that the stack cleanup code in the function
	       epilogue is reached.  */
	    break;
	}
      else if ((inst & 0xf800) == 0xd000)	/* sw reg,n($sp) */
	{
	  offset = mips16_get_imm (prev_inst, inst, 8, 4, 0);
	  reg = mips16_to_32_reg[(inst & 0x700) >> 8];
	  PROC_REG_MASK (&temp_proc_desc) |= (1 << reg);
	  set_reg_offset (reg, sp + offset);
	}
      else if ((inst & 0xff00) == 0xf900)	/* sd reg,n($sp) */
	{
	  offset = mips16_get_imm (prev_inst, inst, 5, 8, 0);
	  reg = mips16_to_32_reg[(inst & 0xe0) >> 5];
	  PROC_REG_MASK (&temp_proc_desc) |= (1 << reg);
	  set_reg_offset (reg, sp + offset);
	}
      else if ((inst & 0xff00) == 0x6200)	/* sw $ra,n($sp) */
	{
	  offset = mips16_get_imm (prev_inst, inst, 8, 4, 0);
	  PROC_REG_MASK (&temp_proc_desc) |= (1 << RA_REGNUM);
	  set_reg_offset (RA_REGNUM, sp + offset);
	}
      else if ((inst & 0xff00) == 0xfa00)	/* sd $ra,n($sp) */
	{
	  offset = mips16_get_imm (prev_inst, inst, 8, 8, 0);
	  PROC_REG_MASK (&temp_proc_desc) |= (1 << RA_REGNUM);
	  set_reg_offset (RA_REGNUM, sp + offset);
	}
      else if (inst == 0x673d)	/* move $s1, $sp */
	{
	  frame_addr = sp;
	  PROC_FRAME_REG (&temp_proc_desc) = 17;
	}
      else if ((inst & 0xff00) == 0x0100)	/* addiu $s1,sp,n */
	{
	  offset = mips16_get_imm (prev_inst, inst, 8, 4, 0);
	  frame_addr = sp + offset;
	  PROC_FRAME_REG (&temp_proc_desc) = 17;
	  PROC_FRAME_ADJUST (&temp_proc_desc) = offset;
	}
      else if ((inst & 0xFF00) == 0xd900)	/* sw reg,offset($s1) */
	{
	  offset = mips16_get_imm (prev_inst, inst, 5, 4, 0);
	  reg = mips16_to_32_reg[(inst & 0xe0) >> 5];
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
	  set_reg_offset (reg, frame_addr + offset);
	}
      else if ((inst & 0xFF00) == 0x7900)	/* sd reg,offset($s1) */
	{
	  offset = mips16_get_imm (prev_inst, inst, 5, 8, 0);
	  reg = mips16_to_32_reg[(inst & 0xe0) >> 5];
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
	  set_reg_offset (reg, frame_addr + offset);
	}
      else if ((inst & 0xf81f) == 0xe809 && (inst & 0x700) != 0x700)	/* entry */
	entry_inst = inst;	/* save for later processing */
      else if ((inst & 0xf800) == 0x1800)	/* jal(x) */
	cur_pc += MIPS16_INSTLEN;	/* 32-bit instruction */
    }

  /* The entry instruction is typically the first instruction in a function,
     and it stores registers at offsets relative to the value of the old SP
     (before the prologue).  But the value of the sp parameter to this
     function is the new SP (after the prologue has been executed).  So we
     can't calculate those offsets until we've seen the entire prologue,
     and can calculate what the old SP must have been. */
  if (entry_inst != 0)
    {
      int areg_count = (entry_inst >> 8) & 7;
      int sreg_count = (entry_inst >> 6) & 3;

      /* The entry instruction always subtracts 32 from the SP.  */
      PROC_FRAME_OFFSET (&temp_proc_desc) += 32;

      /* Now we can calculate what the SP must have been at the
         start of the function prologue.  */
      sp += PROC_FRAME_OFFSET (&temp_proc_desc);

      /* Check if a0-a3 were saved in the caller's argument save area.  */
      for (reg = 4, offset = 0; reg < areg_count + 4; reg++)
	{
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
	  set_reg_offset (reg, sp + offset);
	  offset += MIPS_SAVED_REGSIZE;
	}

      /* Check if the ra register was pushed on the stack.  */
      offset = -4;
      if (entry_inst & 0x20)
	{
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << RA_REGNUM;
	  set_reg_offset (RA_REGNUM, sp + offset);
	  offset -= MIPS_SAVED_REGSIZE;
	}

      /* Check if the s0 and s1 registers were pushed on the stack.  */
      for (reg = 16; reg < sreg_count + 16; reg++)
	{
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
	  set_reg_offset (reg, sp + offset);
	  offset -= MIPS_SAVED_REGSIZE;
	}
    }
}

static void
mips32_heuristic_proc_desc (start_pc, limit_pc, next_frame, sp)
     CORE_ADDR start_pc, limit_pc;
     struct frame_info *next_frame;
     CORE_ADDR sp;
{
  CORE_ADDR cur_pc;
  CORE_ADDR frame_addr = 0;	/* Value of $r30. Used by gcc for frame-pointer */
restart:
  memset (temp_saved_regs, '\0', SIZEOF_FRAME_SAVED_REGS);
  PROC_FRAME_OFFSET (&temp_proc_desc) = 0;
  PROC_FRAME_ADJUST (&temp_proc_desc) = 0;	/* offset of FP from SP */
  for (cur_pc = start_pc; cur_pc < limit_pc; cur_pc += MIPS_INSTLEN)
    {
      unsigned long inst, high_word, low_word;
      int reg;

      /* Fetch the instruction.   */
      inst = (unsigned long) mips_fetch_instruction (cur_pc);

      /* Save some code by pre-extracting some useful fields.  */
      high_word = (inst >> 16) & 0xffff;
      low_word = inst & 0xffff;
      reg = high_word & 0x1f;

      if (high_word == 0x27bd	/* addiu $sp,$sp,-i */
	  || high_word == 0x23bd	/* addi $sp,$sp,-i */
	  || high_word == 0x67bd)	/* daddiu $sp,$sp,-i */
	{
	  if (low_word & 0x8000)	/* negative stack adjustment? */
	    PROC_FRAME_OFFSET (&temp_proc_desc) += 0x10000 - low_word;
	  else
	    /* Exit loop if a positive stack adjustment is found, which
	       usually means that the stack cleanup code in the function
	       epilogue is reached.  */
	    break;
	}
      else if ((high_word & 0xFFE0) == 0xafa0)	/* sw reg,offset($sp) */
	{
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
	  set_reg_offset (reg, sp + low_word);
	}
      else if ((high_word & 0xFFE0) == 0xffa0)	/* sd reg,offset($sp) */
	{
	  /* Irix 6.2 N32 ABI uses sd instructions for saving $gp and $ra,
	     but the register size used is only 32 bits. Make the address
	     for the saved register point to the lower 32 bits.  */
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
	  set_reg_offset (reg, sp + low_word + 8 - MIPS_REGSIZE);
	}
      else if (high_word == 0x27be)	/* addiu $30,$sp,size */
	{
	  /* Old gcc frame, r30 is virtual frame pointer.  */
	  if ((long) low_word != PROC_FRAME_OFFSET (&temp_proc_desc))
	    frame_addr = sp + low_word;
	  else if (PROC_FRAME_REG (&temp_proc_desc) == SP_REGNUM)
	    {
	      unsigned alloca_adjust;
	      PROC_FRAME_REG (&temp_proc_desc) = 30;
	      frame_addr = read_next_frame_reg (next_frame, 30);
	      alloca_adjust = (unsigned) (frame_addr - (sp + low_word));
	      if (alloca_adjust > 0)
		{
		  /* FP > SP + frame_size. This may be because
		   * of an alloca or somethings similar.
		   * Fix sp to "pre-alloca" value, and try again.
		   */
		  sp += alloca_adjust;
		  goto restart;
		}
	    }
	}
      /* move $30,$sp.  With different versions of gas this will be either
         `addu $30,$sp,$zero' or `or $30,$sp,$zero' or `daddu 30,sp,$0'.
         Accept any one of these.  */
      else if (inst == 0x03A0F021 || inst == 0x03a0f025 || inst == 0x03a0f02d)
	{
	  /* New gcc frame, virtual frame pointer is at r30 + frame_size.  */
	  if (PROC_FRAME_REG (&temp_proc_desc) == SP_REGNUM)
	    {
	      unsigned alloca_adjust;
	      PROC_FRAME_REG (&temp_proc_desc) = 30;
	      frame_addr = read_next_frame_reg (next_frame, 30);
	      alloca_adjust = (unsigned) (frame_addr - sp);
	      if (alloca_adjust > 0)
		{
		  /* FP > SP + frame_size. This may be because
		   * of an alloca or somethings similar.
		   * Fix sp to "pre-alloca" value, and try again.
		   */
		  sp += alloca_adjust;
		  goto restart;
		}
	    }
	}
      else if ((high_word & 0xFFE0) == 0xafc0)	/* sw reg,offset($30) */
	{
	  PROC_REG_MASK (&temp_proc_desc) |= 1 << reg;
	  set_reg_offset (reg, frame_addr + low_word);
	}
    }
}

static mips_extra_func_info_t
heuristic_proc_desc (start_pc, limit_pc, next_frame)
     CORE_ADDR start_pc, limit_pc;
     struct frame_info *next_frame;
{
  CORE_ADDR sp = read_next_frame_reg (next_frame, SP_REGNUM);

  if (start_pc == 0)
    return NULL;
  memset (&temp_proc_desc, '\0', sizeof (temp_proc_desc));
  memset (&temp_saved_regs, '\0', SIZEOF_FRAME_SAVED_REGS);
  PROC_LOW_ADDR (&temp_proc_desc) = start_pc;
  PROC_FRAME_REG (&temp_proc_desc) = SP_REGNUM;
  PROC_PC_REG (&temp_proc_desc) = RA_REGNUM;

  if (start_pc + 200 < limit_pc)
    limit_pc = start_pc + 200;
  if (pc_is_mips16 (start_pc))
    mips16_heuristic_proc_desc (start_pc, limit_pc, next_frame, sp);
  else
    mips32_heuristic_proc_desc (start_pc, limit_pc, next_frame, sp);
  return &temp_proc_desc;
}

static mips_extra_func_info_t
non_heuristic_proc_desc (pc, addrptr)
     CORE_ADDR pc;
     CORE_ADDR *addrptr;
{
  CORE_ADDR startaddr;
  mips_extra_func_info_t proc_desc;
  struct block *b = block_for_pc (pc);
  struct symbol *sym;

  find_pc_partial_function (pc, NULL, &startaddr, NULL);
  if (addrptr)
    *addrptr = startaddr;
  if (b == NULL || PC_IN_CALL_DUMMY (pc, 0, 0))
    sym = NULL;
  else
    {
      if (startaddr > BLOCK_START (b))
	/* This is the "pathological" case referred to in a comment in
	   print_frame_info.  It might be better to move this check into
	   symbol reading.  */
	sym = NULL;
      else
	sym = lookup_symbol (MIPS_EFI_SYMBOL_NAME, b, LABEL_NAMESPACE, 0, NULL);
    }

  /* If we never found a PDR for this function in symbol reading, then
     examine prologues to find the information.  */
  if (sym)
    {
      proc_desc = (mips_extra_func_info_t) SYMBOL_VALUE (sym);
      if (PROC_FRAME_REG (proc_desc) == -1)
	return NULL;
      else
	return proc_desc;
    }
  else
    return NULL;
}


static mips_extra_func_info_t
find_proc_desc (pc, next_frame)
     CORE_ADDR pc;
     struct frame_info *next_frame;
{
  mips_extra_func_info_t proc_desc;
  CORE_ADDR startaddr;

  proc_desc = non_heuristic_proc_desc (pc, &startaddr);

  if (proc_desc)
    {
      /* IF this is the topmost frame AND
       * (this proc does not have debugging information OR
       * the PC is in the procedure prologue)
       * THEN create a "heuristic" proc_desc (by analyzing
       * the actual code) to replace the "official" proc_desc.
       */
      if (next_frame == NULL)
	{
	  struct symtab_and_line val;
	  struct symbol *proc_symbol =
	  PROC_DESC_IS_DUMMY (proc_desc) ? 0 : PROC_SYMBOL (proc_desc);

	  if (proc_symbol)
	    {
	      val = find_pc_line (BLOCK_START
				  (SYMBOL_BLOCK_VALUE (proc_symbol)),
				  0);
	      val.pc = val.end ? val.end : pc;
	    }
	  if (!proc_symbol || pc < val.pc)
	    {
	      mips_extra_func_info_t found_heuristic =
	      heuristic_proc_desc (PROC_LOW_ADDR (proc_desc),
				   pc, next_frame);
	      if (found_heuristic)
		proc_desc = found_heuristic;
	    }
	}
    }
  else
    {
      /* Is linked_proc_desc_table really necessary?  It only seems to be used
         by procedure call dummys.  However, the procedures being called ought
         to have their own proc_descs, and even if they don't,
         heuristic_proc_desc knows how to create them! */

      register struct linked_proc_info *link;

      for (link = linked_proc_desc_table; link; link = link->next)
	if (PROC_LOW_ADDR (&link->info) <= pc
	    && PROC_HIGH_ADDR (&link->info) > pc)
	  return &link->info;

      if (startaddr == 0)
	startaddr = heuristic_proc_start (pc);

      proc_desc =
	heuristic_proc_desc (startaddr, pc, next_frame);
    }
  return proc_desc;
}

static CORE_ADDR
get_frame_pointer (frame, proc_desc)
     struct frame_info *frame;
     mips_extra_func_info_t proc_desc;
{
  return ADDR_BITS_REMOVE (
		   read_next_frame_reg (frame, PROC_FRAME_REG (proc_desc)) +
	     PROC_FRAME_OFFSET (proc_desc) - PROC_FRAME_ADJUST (proc_desc));
}

mips_extra_func_info_t cached_proc_desc;

CORE_ADDR
mips_frame_chain (frame)
     struct frame_info *frame;
{
  mips_extra_func_info_t proc_desc;
  CORE_ADDR tmp;
  CORE_ADDR saved_pc = FRAME_SAVED_PC (frame);

  if (saved_pc == 0 || inside_entry_file (saved_pc))
    return 0;

  /* Check if the PC is inside a call stub.  If it is, fetch the
     PC of the caller of that stub.  */
  if ((tmp = mips_skip_stub (saved_pc)) != 0)
    saved_pc = tmp;

  /* Look up the procedure descriptor for this PC.  */
  proc_desc = find_proc_desc (saved_pc, frame);
  if (!proc_desc)
    return 0;

  cached_proc_desc = proc_desc;

  /* If no frame pointer and frame size is zero, we must be at end
     of stack (or otherwise hosed).  If we don't check frame size,
     we loop forever if we see a zero size frame.  */
  if (PROC_FRAME_REG (proc_desc) == SP_REGNUM
      && PROC_FRAME_OFFSET (proc_desc) == 0
  /* The previous frame from a sigtramp frame might be frameless
     and have frame size zero.  */
      && !frame->signal_handler_caller)
    return 0;
  else
    return get_frame_pointer (frame, proc_desc);
}

void
mips_init_extra_frame_info (fromleaf, fci)
     int fromleaf;
     struct frame_info *fci;
{
  int regnum;

  /* Use proc_desc calculated in frame_chain */
  mips_extra_func_info_t proc_desc =
  fci->next ? cached_proc_desc : find_proc_desc (fci->pc, fci->next);

  fci->extra_info = (struct frame_extra_info *)
    frame_obstack_alloc (sizeof (struct frame_extra_info));

  fci->saved_regs = NULL;
  fci->extra_info->proc_desc =
    proc_desc == &temp_proc_desc ? 0 : proc_desc;
  if (proc_desc)
    {
      /* Fixup frame-pointer - only needed for top frame */
      /* This may not be quite right, if proc has a real frame register.
         Get the value of the frame relative sp, procedure might have been
         interrupted by a signal at it's very start.  */
      if (fci->pc == PROC_LOW_ADDR (proc_desc)
	  && !PROC_DESC_IS_DUMMY (proc_desc))
	fci->frame = read_next_frame_reg (fci->next, SP_REGNUM);
      else
	fci->frame = get_frame_pointer (fci->next, proc_desc);

      if (proc_desc == &temp_proc_desc)
	{
	  char *name;

	  /* Do not set the saved registers for a sigtramp frame,
	     mips_find_saved_registers will do that for us.
	     We can't use fci->signal_handler_caller, it is not yet set.  */
	  find_pc_partial_function (fci->pc, &name,
				    (CORE_ADDR *) NULL, (CORE_ADDR *) NULL);
	  if (!IN_SIGTRAMP (fci->pc, name))
	    {
	      frame_saved_regs_zalloc (fci);
	      memcpy (fci->saved_regs, temp_saved_regs, SIZEOF_FRAME_SAVED_REGS);
	      fci->saved_regs[PC_REGNUM]
		= fci->saved_regs[RA_REGNUM];
	    }
	}

      /* hack: if argument regs are saved, guess these contain args */
      /* assume we can't tell how many args for now */
      fci->extra_info->num_args = -1;
      for (regnum = MIPS_LAST_ARG_REGNUM; regnum >= A0_REGNUM; regnum--)
	{
	  if (PROC_REG_MASK (proc_desc) & (1 << regnum))
	    {
	      fci->extra_info->num_args = regnum - A0_REGNUM + 1;
	      break;
	    }
	}
    }
}

/* MIPS stack frames are almost impenetrable.  When execution stops,
   we basically have to look at symbol information for the function
   that we stopped in, which tells us *which* register (if any) is
   the base of the frame pointer, and what offset from that register
   the frame itself is at.  

   This presents a problem when trying to examine a stack in memory
   (that isn't executing at the moment), using the "frame" command.  We
   don't have a PC, nor do we have any registers except SP.

   This routine takes two arguments, SP and PC, and tries to make the
   cached frames look as if these two arguments defined a frame on the
   cache.  This allows the rest of info frame to extract the important
   arguments without difficulty.  */

struct frame_info *
setup_arbitrary_frame (argc, argv)
     int argc;
     CORE_ADDR *argv;
{
  if (argc != 2)
    error ("MIPS frame specifications require two arguments: sp and pc");

  return create_new_frame (argv[0], argv[1]);
}

/*
 * STACK_ARGSIZE -- how many bytes does a pushed function arg take up on the stack?
 *
 * For n32 ABI, eight.
 * For all others, he same as the size of a general register.
 */
#if defined (_MIPS_SIM_NABI32) && _MIPS_SIM == _MIPS_SIM_NABI32
#define MIPS_NABI32   1
#define STACK_ARGSIZE 8
#else
#define MIPS_NABI32   0
#define STACK_ARGSIZE MIPS_SAVED_REGSIZE
#endif

CORE_ADDR
mips_push_arguments (nargs, args, sp, struct_return, struct_addr)
     int nargs;
     value_ptr *args;
     CORE_ADDR sp;
     int struct_return;
     CORE_ADDR struct_addr;
{
  int argreg;
  int float_argreg;
  int argnum;
  int len = 0;
  int stack_offset = 0;

  /* Macros to round N up or down to the next A boundary; A must be
     a power of two. */
#define ROUND_DOWN(n,a) ((n) & ~((a)-1))
#define ROUND_UP(n,a) (((n)+(a)-1) & ~((a)-1))

  /* First ensure that the stack and structure return address (if any)
     are properly aligned. The stack has to be at least 64-bit aligned
     even on 32-bit machines, because doubles must be 64-bit aligned.
     On at least one MIPS variant, stack frames need to be 128-bit
     aligned, so we round to this widest known alignment. */
  sp = ROUND_DOWN (sp, 16);
  struct_addr = ROUND_DOWN (struct_addr, MIPS_SAVED_REGSIZE);

  /* Now make space on the stack for the args. We allocate more
     than necessary for EABI, because the first few arguments are
     passed in registers, but that's OK. */
  for (argnum = 0; argnum < nargs; argnum++)
    len += ROUND_UP (TYPE_LENGTH (VALUE_TYPE (args[argnum])), MIPS_SAVED_REGSIZE);
  sp -= ROUND_UP (len, 16);

  /* Initialize the integer and float register pointers.  */
  argreg = A0_REGNUM;
  float_argreg = FPA0_REGNUM;

  /* the struct_return pointer occupies the first parameter-passing reg */
  if (struct_return)
    write_register (argreg++, struct_addr);

  /* Now load as many as possible of the first arguments into
     registers, and push the rest onto the stack.  Loop thru args
     from first to last.  */
  for (argnum = 0; argnum < nargs; argnum++)
    {
      char *val;
      char valbuf[MAX_REGISTER_RAW_SIZE];
      value_ptr arg = args[argnum];
      struct type *arg_type = check_typedef (VALUE_TYPE (arg));
      int len = TYPE_LENGTH (arg_type);
      enum type_code typecode = TYPE_CODE (arg_type);

      /* The EABI passes structures that do not fit in a register by
         reference. In all other cases, pass the structure by value.  */
      if (MIPS_EABI && len > MIPS_SAVED_REGSIZE &&
	  (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION))
	{
	  store_address (valbuf, MIPS_SAVED_REGSIZE, VALUE_ADDRESS (arg));
	  typecode = TYPE_CODE_PTR;
	  len = MIPS_SAVED_REGSIZE;
	  val = valbuf;
	}
      else
	val = (char *) VALUE_CONTENTS (arg);

      /* 32-bit ABIs always start floating point arguments in an
         even-numbered floating point register.   */
      if (!FP_REGISTER_DOUBLE && typecode == TYPE_CODE_FLT
	  && (float_argreg & 1))
	float_argreg++;

      /* Floating point arguments passed in registers have to be
         treated specially.  On 32-bit architectures, doubles
         are passed in register pairs; the even register gets
         the low word, and the odd register gets the high word.
         On non-EABI processors, the first two floating point arguments are
         also copied to general registers, because MIPS16 functions
         don't use float registers for arguments.  This duplication of
         arguments in general registers can't hurt non-MIPS16 functions
         because those registers are normally skipped.  */
      if (typecode == TYPE_CODE_FLT
	  && float_argreg <= MIPS_LAST_FP_ARG_REGNUM
	  && MIPS_FPU_TYPE != MIPS_FPU_NONE)
	{
	  if (!FP_REGISTER_DOUBLE && len == 8)
	    {
	      int low_offset = TARGET_BYTE_ORDER == BIG_ENDIAN ? 4 : 0;
	      unsigned long regval;

	      /* Write the low word of the double to the even register(s).  */
	      regval = extract_unsigned_integer (val + low_offset, 4);
	      write_register (float_argreg++, regval);
	      if (!MIPS_EABI)
		write_register (argreg + 1, regval);

	      /* Write the high word of the double to the odd register(s).  */
	      regval = extract_unsigned_integer (val + 4 - low_offset, 4);
	      write_register (float_argreg++, regval);
	      if (!MIPS_EABI)
		{
		  write_register (argreg, regval);
		  argreg += 2;
		}

	    }
	  else
	    {
	      /* This is a floating point value that fits entirely
	         in a single register.  */
	      /* On 32 bit ABI's the float_argreg is further adjusted
                 above to ensure that it is even register aligned. */
	      CORE_ADDR regval = extract_address (val, len);
	      write_register (float_argreg++, regval);
	      if (!MIPS_EABI)
		{
		  /* CAGNEY: 32 bit MIPS ABI's always reserve two FP
                     registers for each argument.  The below is (my
                     guess) to ensure that the corresponding integer
                     register has reserved the same space. */
		  write_register (argreg, regval);
		  argreg += FP_REGISTER_DOUBLE ? 1 : 2;
		}
	    }
	}
      else
	{
	  /* Copy the argument to general registers or the stack in
	     register-sized pieces.  Large arguments are split between
	     registers and stack.  */
	  /* Note: structs whose size is not a multiple of MIPS_REGSIZE
	     are treated specially: Irix cc passes them in registers
	     where gcc sometimes puts them on the stack.  For maximum
	     compatibility, we will put them in both places.  */

	  int odd_sized_struct = ((len > MIPS_SAVED_REGSIZE) &&
				  (len % MIPS_SAVED_REGSIZE != 0));
	  while (len > 0)
	    {
	      int partial_len = len < MIPS_SAVED_REGSIZE ? len : MIPS_SAVED_REGSIZE;

	      if (argreg > MIPS_LAST_ARG_REGNUM || odd_sized_struct)
		{
		  /* Write this portion of the argument to the stack.  */
		  /* Should shorter than int integer values be
		     promoted to int before being stored? */

		  int longword_offset = 0;
		  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
		    {
		      if (STACK_ARGSIZE == 8 &&
			  (typecode == TYPE_CODE_INT ||
			   typecode == TYPE_CODE_PTR ||
			   typecode == TYPE_CODE_FLT) && len <= 4)
			longword_offset = STACK_ARGSIZE - len;
		      else if ((typecode == TYPE_CODE_STRUCT ||
				typecode == TYPE_CODE_UNION) &&
			       TYPE_LENGTH (arg_type) < STACK_ARGSIZE)
			longword_offset = STACK_ARGSIZE - len;
		    }

		  write_memory (sp + stack_offset + longword_offset,
				val, partial_len);
		}

	      /* Note!!! This is NOT an else clause.
	         Odd sized structs may go thru BOTH paths.  */
	      if (argreg <= MIPS_LAST_ARG_REGNUM)
		{
		  CORE_ADDR regval = extract_address (val, partial_len);

		  /* A non-floating-point argument being passed in a 
		     general register.  If a struct or union, and if
		     the remaining length is smaller than the register
		     size, we have to adjust the register value on
		     big endian targets.

		     It does not seem to be necessary to do the
		     same for integral types.

		     Also don't do this adjustment on EABI and O64
		     binaries. */

		  if (!MIPS_EABI
		      && MIPS_SAVED_REGSIZE < 8
		      && TARGET_BYTE_ORDER == BIG_ENDIAN
		      && partial_len < MIPS_SAVED_REGSIZE
		      && (typecode == TYPE_CODE_STRUCT ||
			  typecode == TYPE_CODE_UNION))
		    regval <<= ((MIPS_SAVED_REGSIZE - partial_len) *
				TARGET_CHAR_BIT);

		  write_register (argreg, regval);
		  argreg++;

		  /* If this is the old ABI, prevent subsequent floating
		     point arguments from being passed in floating point
		     registers.  */
		  if (!MIPS_EABI)
		    float_argreg = MIPS_LAST_FP_ARG_REGNUM + 1;
		}

	      len -= partial_len;
	      val += partial_len;

	      /* The offset onto the stack at which we will start
	         copying parameters (after the registers are used up) 
	         begins at (4 * MIPS_REGSIZE) in the old ABI.  This 
	         leaves room for the "home" area for register parameters.

	         In the new EABI (and the NABI32), the 8 register parameters 
	         do not have "home" stack space reserved for them, so the
	         stack offset does not get incremented until after
	         we have used up the 8 parameter registers.  */

	      if (!(MIPS_EABI || MIPS_NABI32) ||
		  argnum >= 8)
		stack_offset += ROUND_UP (partial_len, STACK_ARGSIZE);
	    }
	}
    }

  /* Return adjusted stack pointer.  */
  return sp;
}

CORE_ADDR
mips_push_return_address (pc, sp)
     CORE_ADDR pc;
     CORE_ADDR sp;
{
  /* Set the return address register to point to the entry
     point of the program, where a breakpoint lies in wait.  */
  write_register (RA_REGNUM, CALL_DUMMY_ADDRESS ());
  return sp;
}

static void
mips_push_register (CORE_ADDR * sp, int regno)
{
  char buffer[MAX_REGISTER_RAW_SIZE];
  int regsize;
  int offset;
  if (MIPS_SAVED_REGSIZE < REGISTER_RAW_SIZE (regno))
    {
      regsize = MIPS_SAVED_REGSIZE;
      offset = (TARGET_BYTE_ORDER == BIG_ENDIAN
		? REGISTER_RAW_SIZE (regno) - MIPS_SAVED_REGSIZE
		: 0);
    }
  else
    {
      regsize = REGISTER_RAW_SIZE (regno);
      offset = 0;
    }
  *sp -= regsize;
  read_register_gen (regno, buffer);
  write_memory (*sp, buffer + offset, regsize);
}

/* MASK(i,j) == (1<<i) + (1<<(i+1)) + ... + (1<<j)). Assume i<=j<(MIPS_NUMREGS-1). */
#define MASK(i,j) (((1 << ((j)+1))-1) ^ ((1 << (i))-1))

void
mips_push_dummy_frame ()
{
  int ireg;
  struct linked_proc_info *link = (struct linked_proc_info *)
  xmalloc (sizeof (struct linked_proc_info));
  mips_extra_func_info_t proc_desc = &link->info;
  CORE_ADDR sp = ADDR_BITS_REMOVE (read_register (SP_REGNUM));
  CORE_ADDR old_sp = sp;
  link->next = linked_proc_desc_table;
  linked_proc_desc_table = link;

/* FIXME!   are these correct ? */
#define PUSH_FP_REGNUM 16	/* must be a register preserved across calls */
#define GEN_REG_SAVE_MASK MASK(1,16)|MASK(24,28)|(1<<(MIPS_NUMREGS-1))
#define FLOAT_REG_SAVE_MASK MASK(0,19)
#define FLOAT_SINGLE_REG_SAVE_MASK \
  ((1<<18)|(1<<16)|(1<<14)|(1<<12)|(1<<10)|(1<<8)|(1<<6)|(1<<4)|(1<<2)|(1<<0))
  /*
   * The registers we must save are all those not preserved across
   * procedure calls. Dest_Reg (see tm-mips.h) must also be saved.
   * In addition, we must save the PC, PUSH_FP_REGNUM, MMLO/-HI
   * and FP Control/Status registers.
   * 
   *
   * Dummy frame layout:
   *  (high memory)
   *    Saved PC
   *    Saved MMHI, MMLO, FPC_CSR
   *    Saved R31
   *    Saved R28
   *    ...
   *    Saved R1
   *    Saved D18 (i.e. F19, F18)
   *    ...
   *    Saved D0 (i.e. F1, F0)
   *    Argument build area and stack arguments written via mips_push_arguments
   *  (low memory)
   */

  /* Save special registers (PC, MMHI, MMLO, FPC_CSR) */
  PROC_FRAME_REG (proc_desc) = PUSH_FP_REGNUM;
  PROC_FRAME_OFFSET (proc_desc) = 0;
  PROC_FRAME_ADJUST (proc_desc) = 0;
  mips_push_register (&sp, PC_REGNUM);
  mips_push_register (&sp, HI_REGNUM);
  mips_push_register (&sp, LO_REGNUM);
  mips_push_register (&sp, MIPS_FPU_TYPE == MIPS_FPU_NONE ? 0 : FCRCS_REGNUM);

  /* Save general CPU registers */
  PROC_REG_MASK (proc_desc) = GEN_REG_SAVE_MASK;
  /* PROC_REG_OFFSET is the offset of the first saved register from FP.  */
  PROC_REG_OFFSET (proc_desc) = sp - old_sp - MIPS_SAVED_REGSIZE;
  for (ireg = 32; --ireg >= 0;)
    if (PROC_REG_MASK (proc_desc) & (1 << ireg))
      mips_push_register (&sp, ireg);

  /* Save floating point registers starting with high order word */
  PROC_FREG_MASK (proc_desc) =
    MIPS_FPU_TYPE == MIPS_FPU_DOUBLE ? FLOAT_REG_SAVE_MASK
    : MIPS_FPU_TYPE == MIPS_FPU_SINGLE ? FLOAT_SINGLE_REG_SAVE_MASK : 0;
  /* PROC_FREG_OFFSET is the offset of the first saved *double* register
     from FP.  */
  PROC_FREG_OFFSET (proc_desc) = sp - old_sp - 8;
  for (ireg = 32; --ireg >= 0;)
    if (PROC_FREG_MASK (proc_desc) & (1 << ireg))
      mips_push_register (&sp, ireg + FP0_REGNUM);

  /* Update the frame pointer for the call dummy and the stack pointer.
     Set the procedure's starting and ending addresses to point to the
     call dummy address at the entry point.  */
  write_register (PUSH_FP_REGNUM, old_sp);
  write_register (SP_REGNUM, sp);
  PROC_LOW_ADDR (proc_desc) = CALL_DUMMY_ADDRESS ();
  PROC_HIGH_ADDR (proc_desc) = CALL_DUMMY_ADDRESS () + 4;
  SET_PROC_DESC_IS_DUMMY (proc_desc);
  PROC_PC_REG (proc_desc) = RA_REGNUM;
}

void
mips_pop_frame ()
{
  register int regnum;
  struct frame_info *frame = get_current_frame ();
  CORE_ADDR new_sp = FRAME_FP (frame);

  mips_extra_func_info_t proc_desc = frame->extra_info->proc_desc;

  write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
  if (frame->saved_regs == NULL)
    mips_find_saved_regs (frame);
  for (regnum = 0; regnum < NUM_REGS; regnum++)
    {
      if (regnum != SP_REGNUM && regnum != PC_REGNUM
	  && frame->saved_regs[regnum])
	write_register (regnum,
			read_memory_integer (frame->saved_regs[regnum],
					     MIPS_SAVED_REGSIZE));
    }
  write_register (SP_REGNUM, new_sp);
  flush_cached_frames ();

  if (proc_desc && PROC_DESC_IS_DUMMY (proc_desc))
    {
      struct linked_proc_info *pi_ptr, *prev_ptr;

      for (pi_ptr = linked_proc_desc_table, prev_ptr = NULL;
	   pi_ptr != NULL;
	   prev_ptr = pi_ptr, pi_ptr = pi_ptr->next)
	{
	  if (&pi_ptr->info == proc_desc)
	    break;
	}

      if (pi_ptr == NULL)
	error ("Can't locate dummy extra frame info\n");

      if (prev_ptr != NULL)
	prev_ptr->next = pi_ptr->next;
      else
	linked_proc_desc_table = pi_ptr->next;

      free (pi_ptr);

      write_register (HI_REGNUM,
		      read_memory_integer (new_sp - 2 * MIPS_SAVED_REGSIZE,
					   MIPS_SAVED_REGSIZE));
      write_register (LO_REGNUM,
		      read_memory_integer (new_sp - 3 * MIPS_SAVED_REGSIZE,
					   MIPS_SAVED_REGSIZE));
      if (MIPS_FPU_TYPE != MIPS_FPU_NONE)
	write_register (FCRCS_REGNUM,
			read_memory_integer (new_sp - 4 * MIPS_SAVED_REGSIZE,
					     MIPS_SAVED_REGSIZE));
    }
}

static void
mips_print_register (regnum, all)
     int regnum, all;
{
  char raw_buffer[MAX_REGISTER_RAW_SIZE];

  /* Get the data in raw format.  */
  if (read_relative_register_raw_bytes (regnum, raw_buffer))
    {
      printf_filtered ("%s: [Invalid]", REGISTER_NAME (regnum));
      return;
    }

  /* If an even floating point register, also print as double. */
  if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum)) == TYPE_CODE_FLT
      && !((regnum - FP0_REGNUM) & 1))
    if (REGISTER_RAW_SIZE (regnum) == 4)	/* this would be silly on MIPS64 or N32 (Irix 6) */
      {
	char dbuffer[2 * MAX_REGISTER_RAW_SIZE];

	read_relative_register_raw_bytes (regnum, dbuffer);
	read_relative_register_raw_bytes (regnum + 1, dbuffer + MIPS_REGSIZE);
	REGISTER_CONVERT_TO_TYPE (regnum, builtin_type_double, dbuffer);

	printf_filtered ("(d%d: ", regnum - FP0_REGNUM);
	val_print (builtin_type_double, dbuffer, 0, 0,
		   gdb_stdout, 0, 1, 0, Val_pretty_default);
	printf_filtered ("); ");
      }
  fputs_filtered (REGISTER_NAME (regnum), gdb_stdout);

  /* The problem with printing numeric register names (r26, etc.) is that
     the user can't use them on input.  Probably the best solution is to
     fix it so that either the numeric or the funky (a2, etc.) names
     are accepted on input.  */
  if (regnum < MIPS_NUMREGS)
    printf_filtered ("(r%d): ", regnum);
  else
    printf_filtered (": ");

  /* If virtual format is floating, print it that way.  */
  if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum)) == TYPE_CODE_FLT)
    if (FP_REGISTER_DOUBLE)
      {				/* show 8-byte floats as float AND double: */
	int offset = 4 * (TARGET_BYTE_ORDER == BIG_ENDIAN);

	printf_filtered (" (float) ");
	val_print (builtin_type_float, raw_buffer + offset, 0, 0,
		   gdb_stdout, 0, 1, 0, Val_pretty_default);
	printf_filtered (", (double) ");
	val_print (builtin_type_double, raw_buffer, 0, 0,
		   gdb_stdout, 0, 1, 0, Val_pretty_default);
      }
    else
      val_print (REGISTER_VIRTUAL_TYPE (regnum), raw_buffer, 0, 0,
		 gdb_stdout, 0, 1, 0, Val_pretty_default);
  /* Else print as integer in hex.  */
  else
    print_scalar_formatted (raw_buffer, REGISTER_VIRTUAL_TYPE (regnum),
			    'x', 0, gdb_stdout);
}

/* Replacement for generic do_registers_info.  
   Print regs in pretty columns.  */

static int
do_fp_register_row (regnum)
     int regnum;
{				/* do values for FP (float) regs */
  char *raw_buffer[2];
  char *dbl_buffer;
  /* use HI and LO to control the order of combining two flt regs */
  int HI = (TARGET_BYTE_ORDER == BIG_ENDIAN);
  int LO = (TARGET_BYTE_ORDER != BIG_ENDIAN);
  double doub, flt1, flt2;	/* doubles extracted from raw hex data */
  int inv1, inv2, inv3;

  raw_buffer[0] = (char *) alloca (REGISTER_RAW_SIZE (FP0_REGNUM));
  raw_buffer[1] = (char *) alloca (REGISTER_RAW_SIZE (FP0_REGNUM));
  dbl_buffer = (char *) alloca (2 * REGISTER_RAW_SIZE (FP0_REGNUM));

  /* Get the data in raw format.  */
  if (read_relative_register_raw_bytes (regnum, raw_buffer[HI]))
    error ("can't read register %d (%s)", regnum, REGISTER_NAME (regnum));
  if (REGISTER_RAW_SIZE (regnum) == 4)
    {
      /* 4-byte registers: we can fit two registers per row. */
      /* Also print every pair of 4-byte regs as an 8-byte double. */
      if (read_relative_register_raw_bytes (regnum + 1, raw_buffer[LO]))
	error ("can't read register %d (%s)",
	       regnum + 1, REGISTER_NAME (regnum + 1));

      /* copy the two floats into one double, and unpack both */
      memcpy (dbl_buffer, raw_buffer, sizeof (dbl_buffer));
      flt1 = unpack_double (builtin_type_float, raw_buffer[HI], &inv1);
      flt2 = unpack_double (builtin_type_float, raw_buffer[LO], &inv2);
      doub = unpack_double (builtin_type_double, dbl_buffer, &inv3);

      printf_filtered (inv1 ? " %-5s: <invalid float>" :
		       " %-5s%-17.9g", REGISTER_NAME (regnum), flt1);
      printf_filtered (inv2 ? " %-5s: <invalid float>" :
		       " %-5s%-17.9g", REGISTER_NAME (regnum + 1), flt2);
      printf_filtered (inv3 ? " dbl: <invalid double>\n" :
		       " dbl: %-24.17g\n", doub);
      /* may want to do hex display here (future enhancement) */
      regnum += 2;
    }
  else
    {				/* eight byte registers: print each one as float AND as double. */
      int offset = 4 * (TARGET_BYTE_ORDER == BIG_ENDIAN);

      memcpy (dbl_buffer, raw_buffer[HI], sizeof (dbl_buffer));
      flt1 = unpack_double (builtin_type_float,
			    &raw_buffer[HI][offset], &inv1);
      doub = unpack_double (builtin_type_double, dbl_buffer, &inv3);

      printf_filtered (inv1 ? " %-5s: <invalid float>" :
		       " %-5s flt: %-17.9g", REGISTER_NAME (regnum), flt1);
      printf_filtered (inv3 ? " dbl: <invalid double>\n" :
		       " dbl: %-24.17g\n", doub);
      /* may want to do hex display here (future enhancement) */
      regnum++;
    }
  return regnum;
}

/* Print a row's worth of GP (int) registers, with name labels above */

static int
do_gp_register_row (regnum)
     int regnum;
{
  /* do values for GP (int) regs */
  char raw_buffer[MAX_REGISTER_RAW_SIZE];
  int ncols = (MIPS_REGSIZE == 8 ? 4 : 8);	/* display cols per row */
  int col, byte;
  int start_regnum = regnum;
  int numregs = NUM_REGS;


  /* For GP registers, we print a separate row of names above the vals */
  printf_filtered ("     ");
  for (col = 0; col < ncols && regnum < numregs; regnum++)
    {
      if (*REGISTER_NAME (regnum) == '\0')
	continue;		/* unused register */
      if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum)) == TYPE_CODE_FLT)
	break;			/* end the row: reached FP register */
      printf_filtered (MIPS_REGSIZE == 8 ? "%17s" : "%9s",
		       REGISTER_NAME (regnum));
      col++;
    }
  printf_filtered (start_regnum < MIPS_NUMREGS ? "\n R%-4d" : "\n      ",
		   start_regnum);	/* print the R0 to R31 names */

  regnum = start_regnum;	/* go back to start of row */
  /* now print the values in hex, 4 or 8 to the row */
  for (col = 0; col < ncols && regnum < numregs; regnum++)
    {
      if (*REGISTER_NAME (regnum) == '\0')
	continue;		/* unused register */
      if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum)) == TYPE_CODE_FLT)
	break;			/* end row: reached FP register */
      /* OK: get the data in raw format.  */
      if (read_relative_register_raw_bytes (regnum, raw_buffer))
	error ("can't read register %d (%s)", regnum, REGISTER_NAME (regnum));
      /* pad small registers */
      for (byte = 0; byte < (MIPS_REGSIZE - REGISTER_VIRTUAL_SIZE (regnum)); byte++)
	printf_filtered ("  ");
      /* Now print the register value in hex, endian order. */
      if (TARGET_BYTE_ORDER == BIG_ENDIAN)
	for (byte = REGISTER_RAW_SIZE (regnum) - REGISTER_VIRTUAL_SIZE (regnum);
	     byte < REGISTER_RAW_SIZE (regnum);
	     byte++)
	  printf_filtered ("%02x", (unsigned char) raw_buffer[byte]);
      else
	for (byte = REGISTER_VIRTUAL_SIZE (regnum) - 1;
	     byte >= 0;
	     byte--)
	  printf_filtered ("%02x", (unsigned char) raw_buffer[byte]);
      printf_filtered (" ");
      col++;
    }
  if (col > 0)			/* ie. if we actually printed anything... */
    printf_filtered ("\n");

  return regnum;
}

/* MIPS_DO_REGISTERS_INFO(): called by "info register" command */

void
mips_do_registers_info (regnum, fpregs)
     int regnum;
     int fpregs;
{
  if (regnum != -1)		/* do one specified register */
    {
      if (*(REGISTER_NAME (regnum)) == '\0')
	error ("Not a valid register for the current processor type");

      mips_print_register (regnum, 0);
      printf_filtered ("\n");
    }
  else
    /* do all (or most) registers */
    {
      regnum = 0;
      while (regnum < NUM_REGS)
	{
	  if (TYPE_CODE (REGISTER_VIRTUAL_TYPE (regnum)) == TYPE_CODE_FLT)
	    if (fpregs)		/* true for "INFO ALL-REGISTERS" command */
	      regnum = do_fp_register_row (regnum);	/* FP regs */
	    else
	      regnum += MIPS_NUMREGS;	/* skip floating point regs */
	  else
	    regnum = do_gp_register_row (regnum);	/* GP (int) regs */
	}
    }
}

/* Return number of args passed to a frame. described by FIP.
   Can return -1, meaning no way to tell.  */

int
mips_frame_num_args (frame)
     struct frame_info *frame;
{
#if 0				/* FIXME Use or lose this! */
  struct chain_info_t *p;

  p = mips_find_cached_frame (FRAME_FP (frame));
  if (p->valid)
    return p->the_info.numargs;
#endif
  return -1;
}

/* Is this a branch with a delay slot?  */

static int is_delayed PARAMS ((unsigned long));

static int
is_delayed (insn)
     unsigned long insn;
{
  int i;
  for (i = 0; i < NUMOPCODES; ++i)
    if (mips_opcodes[i].pinfo != INSN_MACRO
	&& (insn & mips_opcodes[i].mask) == mips_opcodes[i].match)
      break;
  return (i < NUMOPCODES
	  && (mips_opcodes[i].pinfo & (INSN_UNCOND_BRANCH_DELAY
				       | INSN_COND_BRANCH_DELAY
				       | INSN_COND_BRANCH_LIKELY)));
}

int
mips_step_skips_delay (pc)
     CORE_ADDR pc;
{
  char buf[MIPS_INSTLEN];

  /* There is no branch delay slot on MIPS16.  */
  if (pc_is_mips16 (pc))
    return 0;

  if (target_read_memory (pc, buf, MIPS_INSTLEN) != 0)
    /* If error reading memory, guess that it is not a delayed branch.  */
    return 0;
  return is_delayed ((unsigned long) extract_unsigned_integer (buf, MIPS_INSTLEN));
}


/* Skip the PC past function prologue instructions (32-bit version).
   This is a helper function for mips_skip_prologue.  */

static CORE_ADDR
mips32_skip_prologue (pc, lenient)
     CORE_ADDR pc;		/* starting PC to search from */
     int lenient;
{
  t_inst inst;
  CORE_ADDR end_pc;
  int seen_sp_adjust = 0;
  int load_immediate_bytes = 0;

  /* Skip the typical prologue instructions. These are the stack adjustment
     instruction and the instructions that save registers on the stack
     or in the gcc frame.  */
  for (end_pc = pc + 100; pc < end_pc; pc += MIPS_INSTLEN)
    {
      unsigned long high_word;

      inst = mips_fetch_instruction (pc);
      high_word = (inst >> 16) & 0xffff;

#if 0
      if (lenient && is_delayed (inst))
	continue;
#endif

      if (high_word == 0x27bd	/* addiu $sp,$sp,offset */
	  || high_word == 0x67bd)	/* daddiu $sp,$sp,offset */
	seen_sp_adjust = 1;
      else if (inst == 0x03a1e823 ||	/* subu $sp,$sp,$at */
	       inst == 0x03a8e823)	/* subu $sp,$sp,$t0 */
	seen_sp_adjust = 1;
      else if (((inst & 0xFFE00000) == 0xAFA00000	/* sw reg,n($sp) */
		|| (inst & 0xFFE00000) == 0xFFA00000)	/* sd reg,n($sp) */
	       && (inst & 0x001F0000))	/* reg != $zero */
	continue;

      else if ((inst & 0xFFE00000) == 0xE7A00000)	/* swc1 freg,n($sp) */
	continue;
      else if ((inst & 0xF3E00000) == 0xA3C00000 && (inst & 0x001F0000))
	/* sx reg,n($s8) */
	continue;		/* reg != $zero */

      /* move $s8,$sp.  With different versions of gas this will be either
         `addu $s8,$sp,$zero' or `or $s8,$sp,$zero' or `daddu s8,sp,$0'.
         Accept any one of these.  */
      else if (inst == 0x03A0F021 || inst == 0x03a0f025 || inst == 0x03a0f02d)
	continue;

      else if ((inst & 0xFF9F07FF) == 0x00800021)	/* move reg,$a0-$a3 */
	continue;
      else if (high_word == 0x3c1c)	/* lui $gp,n */
	continue;
      else if (high_word == 0x279c)	/* addiu $gp,$gp,n */
	continue;
      else if (inst == 0x0399e021	/* addu $gp,$gp,$t9 */
	       || inst == 0x033ce021)	/* addu $gp,$t9,$gp */
	continue;
      /* The following instructions load $at or $t0 with an immediate
         value in preparation for a stack adjustment via
         subu $sp,$sp,[$at,$t0]. These instructions could also initialize
         a local variable, so we accept them only before a stack adjustment
         instruction was seen.  */
      else if (!seen_sp_adjust)
	{
	  if (high_word == 0x3c01 ||	/* lui $at,n */
	      high_word == 0x3c08)	/* lui $t0,n */
	    {
	      load_immediate_bytes += MIPS_INSTLEN;	/* FIXME!! */
	      continue;
	    }
	  else if (high_word == 0x3421 ||	/* ori $at,$at,n */
		   high_word == 0x3508 ||	/* ori $t0,$t0,n */
		   high_word == 0x3401 ||	/* ori $at,$zero,n */
		   high_word == 0x3408)		/* ori $t0,$zero,n */
	    {
	      load_immediate_bytes += MIPS_INSTLEN;	/* FIXME!! */
	      continue;
	    }
	  else
	    break;
	}
      else
	break;
    }

  /* In a frameless function, we might have incorrectly
     skipped some load immediate instructions. Undo the skipping
     if the load immediate was not followed by a stack adjustment.  */
  if (load_immediate_bytes && !seen_sp_adjust)
    pc -= load_immediate_bytes;
  return pc;
}

/* Skip the PC past function prologue instructions (16-bit version).
   This is a helper function for mips_skip_prologue.  */

static CORE_ADDR
mips16_skip_prologue (pc, lenient)
     CORE_ADDR pc;		/* starting PC to search from */
     int lenient;
{
  CORE_ADDR end_pc;
  int extend_bytes = 0;
  int prev_extend_bytes;

  /* Table of instructions likely to be found in a function prologue.  */
  static struct
    {
      unsigned short inst;
      unsigned short mask;
    }
  table[] =
  {
    {
      0x6300, 0xff00
    }
    ,				/* addiu $sp,offset */
    {
      0xfb00, 0xff00
    }
    ,				/* daddiu $sp,offset */
    {
      0xd000, 0xf800
    }
    ,				/* sw reg,n($sp) */
    {
      0xf900, 0xff00
    }
    ,				/* sd reg,n($sp) */
    {
      0x6200, 0xff00
    }
    ,				/* sw $ra,n($sp) */
    {
      0xfa00, 0xff00
    }
    ,				/* sd $ra,n($sp) */
    {
      0x673d, 0xffff
    }
    ,				/* move $s1,sp */
    {
      0xd980, 0xff80
    }
    ,				/* sw $a0-$a3,n($s1) */
    {
      0x6704, 0xff1c
    }
    ,				/* move reg,$a0-$a3 */
    {
      0xe809, 0xf81f
    }
    ,				/* entry pseudo-op */
    {
      0x0100, 0xff00
    }
    ,				/* addiu $s1,$sp,n */
    {
      0, 0
    }				/* end of table marker */
  };

  /* Skip the typical prologue instructions. These are the stack adjustment
     instruction and the instructions that save registers on the stack
     or in the gcc frame.  */
  for (end_pc = pc + 100; pc < end_pc; pc += MIPS16_INSTLEN)
    {
      unsigned short inst;
      int i;

      inst = mips_fetch_instruction (pc);

      /* Normally we ignore an extend instruction.  However, if it is
         not followed by a valid prologue instruction, we must adjust
         the pc back over the extend so that it won't be considered
         part of the prologue.  */
      if ((inst & 0xf800) == 0xf000)	/* extend */
	{
	  extend_bytes = MIPS16_INSTLEN;
	  continue;
	}
      prev_extend_bytes = extend_bytes;
      extend_bytes = 0;

      /* Check for other valid prologue instructions besides extend.  */
      for (i = 0; table[i].mask != 0; i++)
	if ((inst & table[i].mask) == table[i].inst)	/* found, get out */
	  break;
      if (table[i].mask != 0)	/* it was in table? */
	continue;		/* ignore it */
      else
	/* non-prologue */
	{
	  /* Return the current pc, adjusted backwards by 2 if
	     the previous instruction was an extend.  */
	  return pc - prev_extend_bytes;
	}
    }
  return pc;
}

/* To skip prologues, I use this predicate.  Returns either PC itself
   if the code at PC does not look like a function prologue; otherwise
   returns an address that (if we're lucky) follows the prologue.  If
   LENIENT, then we must skip everything which is involved in setting
   up the frame (it's OK to skip more, just so long as we don't skip
   anything which might clobber the registers which are being saved.
   We must skip more in the case where part of the prologue is in the
   delay slot of a non-prologue instruction).  */

CORE_ADDR
mips_skip_prologue (pc, lenient)
     CORE_ADDR pc;
     int lenient;
{
  /* See if we can determine the end of the prologue via the symbol table.
     If so, then return either PC, or the PC after the prologue, whichever
     is greater.  */

  CORE_ADDR post_prologue_pc = after_prologue (pc, NULL);

  if (post_prologue_pc != 0)
    return max (pc, post_prologue_pc);

  /* Can't determine prologue from the symbol table, need to examine
     instructions.  */

  if (pc_is_mips16 (pc))
    return mips16_skip_prologue (pc, lenient);
  else
    return mips32_skip_prologue (pc, lenient);
}

#if 0
/* The lenient prologue stuff should be superseded by the code in
   init_extra_frame_info which looks to see whether the stores mentioned
   in the proc_desc have actually taken place.  */

/* Is address PC in the prologue (loosely defined) for function at
   STARTADDR?  */

static int
mips_in_lenient_prologue (startaddr, pc)
     CORE_ADDR startaddr;
     CORE_ADDR pc;
{
  CORE_ADDR end_prologue = mips_skip_prologue (startaddr, 1);
  return pc >= startaddr && pc < end_prologue;
}
#endif

/* Determine how a return value is stored within the MIPS register
   file, given the return type `valtype'. */

struct return_value_word
{
  int len;
  int reg;
  int reg_offset;
  int buf_offset;
};

static void return_value_location PARAMS ((struct type *, struct return_value_word *, struct return_value_word *));

static void
return_value_location (valtype, hi, lo)
     struct type *valtype;
     struct return_value_word *hi;
     struct return_value_word *lo;
{
  int len = TYPE_LENGTH (valtype);

  if (TYPE_CODE (valtype) == TYPE_CODE_FLT
      && ((MIPS_FPU_TYPE == MIPS_FPU_DOUBLE && (len == 4 || len == 8))
	  || (MIPS_FPU_TYPE == MIPS_FPU_SINGLE && len == 4)))
    {
      if (!FP_REGISTER_DOUBLE && len == 8)
	{
	  /* We need to break a 64bit float in two 32 bit halves and
	     spread them across a floating-point register pair. */
	  lo->buf_offset = TARGET_BYTE_ORDER == BIG_ENDIAN ? 4 : 0;
	  hi->buf_offset = TARGET_BYTE_ORDER == BIG_ENDIAN ? 0 : 4;
	  lo->reg_offset = ((TARGET_BYTE_ORDER == BIG_ENDIAN
			     && REGISTER_RAW_SIZE (FP0_REGNUM) == 8)
			    ? 4 : 0);
	  hi->reg_offset = lo->reg_offset;
	  lo->reg = FP0_REGNUM + 0;
	  hi->reg = FP0_REGNUM + 1;
	  lo->len = 4;
	  hi->len = 4;
	}
      else
	{
	  /* The floating point value fits in a single floating-point
	     register. */
	  lo->reg_offset = ((TARGET_BYTE_ORDER == BIG_ENDIAN
			     && REGISTER_RAW_SIZE (FP0_REGNUM) == 8
			     && len == 4)
			    ? 4 : 0);
	  lo->reg = FP0_REGNUM;
	  lo->len = len;
	  lo->buf_offset = 0;
	  hi->len = 0;
	  hi->reg_offset = 0;
	  hi->buf_offset = 0;
	  hi->reg = 0;
	}
    }
  else
    {
      /* Locate a result possibly spread across two registers. */
      int regnum = 2;
      lo->reg = regnum + 0;
      hi->reg = regnum + 1;
      if (TARGET_BYTE_ORDER == BIG_ENDIAN
	  && len < MIPS_SAVED_REGSIZE)
	{
	  /* "un-left-justify" the value in the low register */
	  lo->reg_offset = MIPS_SAVED_REGSIZE - len;
	  lo->len = len;
	  hi->reg_offset = 0;
	  hi->len = 0;
	}
      else if (TARGET_BYTE_ORDER == BIG_ENDIAN
	       && len > MIPS_SAVED_REGSIZE	/* odd-size structs */
	       && len < MIPS_SAVED_REGSIZE * 2
	       && (TYPE_CODE (valtype) == TYPE_CODE_STRUCT ||
		   TYPE_CODE (valtype) == TYPE_CODE_UNION))
	{
	  /* "un-left-justify" the value spread across two registers. */
	  lo->reg_offset = 2 * MIPS_SAVED_REGSIZE - len;
	  lo->len = MIPS_SAVED_REGSIZE - lo->reg_offset;
	  hi->reg_offset = 0;
	  hi->len = len - lo->len;
	}
      else
	{
	  /* Only perform a partial copy of the second register. */
	  lo->reg_offset = 0;
	  hi->reg_offset = 0;
	  if (len > MIPS_SAVED_REGSIZE)
	    {
	      lo->len = MIPS_SAVED_REGSIZE;
	      hi->len = len - MIPS_SAVED_REGSIZE;
	    }
	  else
	    {
	      lo->len = len;
	      hi->len = 0;
	    }
	}
      if (TARGET_BYTE_ORDER == BIG_ENDIAN
	  && REGISTER_RAW_SIZE (regnum) == 8
	  && MIPS_SAVED_REGSIZE == 4)
	{
	  /* Account for the fact that only the least-signficant part
	     of the register is being used */
	  lo->reg_offset += 4;
	  hi->reg_offset += 4;
	}
      lo->buf_offset = 0;
      hi->buf_offset = lo->len;
    }
}

/* Given a return value in `regbuf' with a type `valtype', extract and
   copy its value into `valbuf'. */

void
mips_extract_return_value (valtype, regbuf, valbuf)
     struct type *valtype;
     char regbuf[REGISTER_BYTES];
     char *valbuf;
{
  struct return_value_word lo;
  struct return_value_word hi;
  return_value_location (valtype, &lo, &hi);

  memcpy (valbuf + lo.buf_offset,
	  regbuf + REGISTER_BYTE (lo.reg) + lo.reg_offset,
	  lo.len);

  if (hi.len > 0)
    memcpy (valbuf + hi.buf_offset,
	    regbuf + REGISTER_BYTE (hi.reg) + hi.reg_offset,
	    hi.len);

#if 0
  int regnum;
  int offset = 0;
  int len = TYPE_LENGTH (valtype);

  regnum = 2;
  if (TYPE_CODE (valtype) == TYPE_CODE_FLT
      && (MIPS_FPU_TYPE == MIPS_FPU_DOUBLE
	  || (MIPS_FPU_TYPE == MIPS_FPU_SINGLE
	      && len <= MIPS_FPU_SINGLE_REGSIZE)))
    regnum = FP0_REGNUM;

  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
    {				/* "un-left-justify" the value from the register */
      if (len < REGISTER_RAW_SIZE (regnum))
	offset = REGISTER_RAW_SIZE (regnum) - len;
      if (len > REGISTER_RAW_SIZE (regnum) &&	/* odd-size structs */
	  len < REGISTER_RAW_SIZE (regnum) * 2 &&
	  (TYPE_CODE (valtype) == TYPE_CODE_STRUCT ||
	   TYPE_CODE (valtype) == TYPE_CODE_UNION))
	offset = 2 * REGISTER_RAW_SIZE (regnum) - len;
    }
  memcpy (valbuf, regbuf + REGISTER_BYTE (regnum) + offset, len);
  REGISTER_CONVERT_TO_TYPE (regnum, valtype, valbuf);
#endif
}

/* Given a return value in `valbuf' with a type `valtype', write it's
   value into the appropriate register. */

void
mips_store_return_value (valtype, valbuf)
     struct type *valtype;
     char *valbuf;
{
  char raw_buffer[MAX_REGISTER_RAW_SIZE];
  struct return_value_word lo;
  struct return_value_word hi;
  return_value_location (valtype, &lo, &hi);

  memset (raw_buffer, 0, sizeof (raw_buffer));
  memcpy (raw_buffer + lo.reg_offset, valbuf + lo.buf_offset, lo.len);
  write_register_bytes (REGISTER_BYTE (lo.reg),
			raw_buffer,
			REGISTER_RAW_SIZE (lo.reg));

  if (hi.len > 0)
    {
      memset (raw_buffer, 0, sizeof (raw_buffer));
      memcpy (raw_buffer + hi.reg_offset, valbuf + hi.buf_offset, hi.len);
      write_register_bytes (REGISTER_BYTE (hi.reg),
			    raw_buffer,
			    REGISTER_RAW_SIZE (hi.reg));
    }

#if 0
  int regnum;
  int offset = 0;
  int len = TYPE_LENGTH (valtype);
  char raw_buffer[MAX_REGISTER_RAW_SIZE];

  regnum = 2;
  if (TYPE_CODE (valtype) == TYPE_CODE_FLT
      && (MIPS_FPU_TYPE == MIPS_FPU_DOUBLE
	  || (MIPS_FPU_TYPE == MIPS_FPU_SINGLE
	      && len <= MIPS_REGSIZE)))
    regnum = FP0_REGNUM;

  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
    {				/* "left-justify" the value in the register */
      if (len < REGISTER_RAW_SIZE (regnum))
	offset = REGISTER_RAW_SIZE (regnum) - len;
      if (len > REGISTER_RAW_SIZE (regnum) &&	/* odd-size structs */
	  len < REGISTER_RAW_SIZE (regnum) * 2 &&
	  (TYPE_CODE (valtype) == TYPE_CODE_STRUCT ||
	   TYPE_CODE (valtype) == TYPE_CODE_UNION))
	offset = 2 * REGISTER_RAW_SIZE (regnum) - len;
    }
  memcpy (raw_buffer + offset, valbuf, len);
  REGISTER_CONVERT_FROM_TYPE (regnum, valtype, raw_buffer);
  write_register_bytes (REGISTER_BYTE (regnum), raw_buffer,
			len > REGISTER_RAW_SIZE (regnum) ?
			len : REGISTER_RAW_SIZE (regnum));
#endif
}

/* Exported procedure: Is PC in the signal trampoline code */

int
in_sigtramp (pc, ignore)
     CORE_ADDR pc;
     char *ignore;		/* function name */
{
  if (sigtramp_address == 0)
    fixup_sigtramp ();
  return (pc >= sigtramp_address && pc < sigtramp_end);
}

/* Commands to show/set the MIPS FPU type.  */

static void show_mipsfpu_command PARAMS ((char *, int));
static void
show_mipsfpu_command (args, from_tty)
     char *args;
     int from_tty;
{
  char *msg;
  char *fpu;
  switch (MIPS_FPU_TYPE)
    {
    case MIPS_FPU_SINGLE:
      fpu = "single-precision";
      break;
    case MIPS_FPU_DOUBLE:
      fpu = "double-precision";
      break;
    case MIPS_FPU_NONE:
      fpu = "absent (none)";
      break;
    }
  if (mips_fpu_type_auto)
    printf_unfiltered ("The MIPS floating-point coprocessor is set automatically (currently %s)\n",
		       fpu);
  else
    printf_unfiltered ("The MIPS floating-point coprocessor is assumed to be %s\n",
		       fpu);
}


static void set_mipsfpu_command PARAMS ((char *, int));
static void
set_mipsfpu_command (args, from_tty)
     char *args;
     int from_tty;
{
  printf_unfiltered ("\"set mipsfpu\" must be followed by \"double\", \"single\",\"none\" or \"auto\".\n");
  show_mipsfpu_command (args, from_tty);
}

static void set_mipsfpu_single_command PARAMS ((char *, int));
static void
set_mipsfpu_single_command (args, from_tty)
     char *args;
     int from_tty;
{
  mips_fpu_type = MIPS_FPU_SINGLE;
  mips_fpu_type_auto = 0;
}

static void set_mipsfpu_double_command PARAMS ((char *, int));
static void
set_mipsfpu_double_command (args, from_tty)
     char *args;
     int from_tty;
{
  mips_fpu_type = MIPS_FPU_DOUBLE;
  mips_fpu_type_auto = 0;
}

static void set_mipsfpu_none_command PARAMS ((char *, int));
static void
set_mipsfpu_none_command (args, from_tty)
     char *args;
     int from_tty;
{
  mips_fpu_type = MIPS_FPU_NONE;
  mips_fpu_type_auto = 0;
}

static void set_mipsfpu_auto_command PARAMS ((char *, int));
static void
set_mipsfpu_auto_command (args, from_tty)
     char *args;
     int from_tty;
{
  mips_fpu_type_auto = 1;
}

/* Command to set the processor type.  */

void
mips_set_processor_type_command (args, from_tty)
     char *args;
     int from_tty;
{
  int i;

  if (tmp_mips_processor_type == NULL || *tmp_mips_processor_type == '\0')
    {
      printf_unfiltered ("The known MIPS processor types are as follows:\n\n");
      for (i = 0; mips_processor_type_table[i].name != NULL; ++i)
	printf_unfiltered ("%s\n", mips_processor_type_table[i].name);

      /* Restore the value.  */
      tmp_mips_processor_type = strsave (mips_processor_type);

      return;
    }

  if (!mips_set_processor_type (tmp_mips_processor_type))
    {
      error ("Unknown processor type `%s'.", tmp_mips_processor_type);
      /* Restore its value.  */
      tmp_mips_processor_type = strsave (mips_processor_type);
    }
}

static void
mips_show_processor_type_command (args, from_tty)
     char *args;
     int from_tty;
{
}

/* Modify the actual processor type. */

int
mips_set_processor_type (str)
     char *str;
{
  int i, j;

  if (str == NULL)
    return 0;

  for (i = 0; mips_processor_type_table[i].name != NULL; ++i)
    {
      if (strcasecmp (str, mips_processor_type_table[i].name) == 0)
	{
	  mips_processor_type = str;
	  mips_processor_reg_names = mips_processor_type_table[i].regnames;
	  return 1;
	  /* FIXME tweak fpu flag too */
	}
    }

  return 0;
}

/* Attempt to identify the particular processor model by reading the
   processor id.  */

char *
mips_read_processor_type ()
{
  CORE_ADDR prid;

  prid = read_register (PRID_REGNUM);

  if ((prid & ~0xf) == 0x700)
    return savestring ("r3041", strlen ("r3041"));

  return NULL;
}

/* Just like reinit_frame_cache, but with the right arguments to be
   callable as an sfunc.  */

static void
reinit_frame_cache_sfunc (args, from_tty, c)
     char *args;
     int from_tty;
     struct cmd_list_element *c;
{
  reinit_frame_cache ();
}

int
gdb_print_insn_mips (memaddr, info)
     bfd_vma memaddr;
     disassemble_info *info;
{
  mips_extra_func_info_t proc_desc;

  /* Search for the function containing this address.  Set the low bit
     of the address when searching, in case we were given an even address
     that is the start of a 16-bit function.  If we didn't do this,
     the search would fail because the symbol table says the function
     starts at an odd address, i.e. 1 byte past the given address.  */
  memaddr = ADDR_BITS_REMOVE (memaddr);
  proc_desc = non_heuristic_proc_desc (MAKE_MIPS16_ADDR (memaddr), NULL);

  /* Make an attempt to determine if this is a 16-bit function.  If
     the procedure descriptor exists and the address therein is odd,
     it's definitely a 16-bit function.  Otherwise, we have to just
     guess that if the address passed in is odd, it's 16-bits.  */
  if (proc_desc)
    info->mach = pc_is_mips16 (PROC_LOW_ADDR (proc_desc)) ? 16 : TM_PRINT_INSN_MACH;
  else
    info->mach = pc_is_mips16 (memaddr) ? 16 : TM_PRINT_INSN_MACH;

  /* Round down the instruction address to the appropriate boundary.  */
  memaddr &= (info->mach == 16 ? ~1 : ~3);

  /* Call the appropriate disassembler based on the target endian-ness.  */
  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
    return print_insn_big_mips (memaddr, info);
  else
    return print_insn_little_mips (memaddr, info);
}

/* Old-style breakpoint macros.
   The IDT board uses an unusual breakpoint value, and sometimes gets
   confused when it sees the usual MIPS breakpoint instruction.  */

#define BIG_BREAKPOINT {0, 0x5, 0, 0xd}
#define LITTLE_BREAKPOINT {0xd, 0, 0x5, 0}
#define PMON_BIG_BREAKPOINT {0, 0, 0, 0xd}
#define PMON_LITTLE_BREAKPOINT {0xd, 0, 0, 0}
#define IDT_BIG_BREAKPOINT {0, 0, 0x0a, 0xd}
#define IDT_LITTLE_BREAKPOINT {0xd, 0x0a, 0, 0}
#define MIPS16_BIG_BREAKPOINT {0xe8, 0xa5}
#define MIPS16_LITTLE_BREAKPOINT {0xa5, 0xe8}

/* This function implements the BREAKPOINT_FROM_PC macro.  It uses the program
   counter value to determine whether a 16- or 32-bit breakpoint should be
   used.  It returns a pointer to a string of bytes that encode a breakpoint
   instruction, stores the length of the string to *lenptr, and adjusts pc
   (if necessary) to point to the actual memory location where the
   breakpoint should be inserted.  */

unsigned char *
mips_breakpoint_from_pc (pcptr, lenptr)
     CORE_ADDR *pcptr;
     int *lenptr;
{
  if (TARGET_BYTE_ORDER == BIG_ENDIAN)
    {
      if (pc_is_mips16 (*pcptr))
	{
	  static char mips16_big_breakpoint[] = MIPS16_BIG_BREAKPOINT;
	  *pcptr = UNMAKE_MIPS16_ADDR (*pcptr);
	  *lenptr = sizeof (mips16_big_breakpoint);
	  return mips16_big_breakpoint;
	}
      else
	{
	  static char big_breakpoint[] = BIG_BREAKPOINT;
	  static char pmon_big_breakpoint[] = PMON_BIG_BREAKPOINT;
	  static char idt_big_breakpoint[] = IDT_BIG_BREAKPOINT;

	  *lenptr = sizeof (big_breakpoint);

	  if (strcmp (target_shortname, "mips") == 0)
	    return idt_big_breakpoint;
	  else if (strcmp (target_shortname, "ddb") == 0
		   || strcmp (target_shortname, "pmon") == 0
		   || strcmp (target_shortname, "lsi") == 0)
	    return pmon_big_breakpoint;
	  else
	    return big_breakpoint;
	}
    }
  else
    {
      if (pc_is_mips16 (*pcptr))
	{
	  static char mips16_little_breakpoint[] = MIPS16_LITTLE_BREAKPOINT;
	  *pcptr = UNMAKE_MIPS16_ADDR (*pcptr);
	  *lenptr = sizeof (mips16_little_breakpoint);
	  return mips16_little_breakpoint;
	}
      else
	{
	  static char little_breakpoint[] = LITTLE_BREAKPOINT;
	  static char pmon_little_breakpoint[] = PMON_LITTLE_BREAKPOINT;
	  static char idt_little_breakpoint[] = IDT_LITTLE_BREAKPOINT;

	  *lenptr = sizeof (little_breakpoint);

	  if (strcmp (target_shortname, "mips") == 0)
	    return idt_little_breakpoint;
	  else if (strcmp (target_shortname, "ddb") == 0
		   || strcmp (target_shortname, "pmon") == 0
		   || strcmp (target_shortname, "lsi") == 0)
	    return pmon_little_breakpoint;
	  else
	    return little_breakpoint;
	}
    }
}

/* If PC is in a mips16 call or return stub, return the address of the target
   PC, which is either the callee or the caller.  There are several
   cases which must be handled:

   * If the PC is in __mips16_ret_{d,s}f, this is a return stub and the
   target PC is in $31 ($ra).
   * If the PC is in __mips16_call_stub_{1..10}, this is a call stub
   and the target PC is in $2.
   * If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
   before the jal instruction, this is effectively a call stub
   and the the target PC is in $2.  Otherwise this is effectively
   a return stub and the target PC is in $18.

   See the source code for the stubs in gcc/config/mips/mips16.S for
   gory details.

   This function implements the SKIP_TRAMPOLINE_CODE macro.
 */

CORE_ADDR
mips_skip_stub (pc)
     CORE_ADDR pc;
{
  char *name;
  CORE_ADDR start_addr;

  /* Find the starting address and name of the function containing the PC.  */
  if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0)
    return 0;

  /* If the PC is in __mips16_ret_{d,s}f, this is a return stub and the
     target PC is in $31 ($ra).  */
  if (strcmp (name, "__mips16_ret_sf") == 0
      || strcmp (name, "__mips16_ret_df") == 0)
    return read_register (RA_REGNUM);

  if (strncmp (name, "__mips16_call_stub_", 19) == 0)
    {
      /* If the PC is in __mips16_call_stub_{1..10}, this is a call stub
         and the target PC is in $2.  */
      if (name[19] >= '0' && name[19] <= '9')
	return read_register (2);

      /* If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
         before the jal instruction, this is effectively a call stub
         and the the target PC is in $2.  Otherwise this is effectively
         a return stub and the target PC is in $18.  */
      else if (name[19] == 's' || name[19] == 'd')
	{
	  if (pc == start_addr)
	    {
	      /* Check if the target of the stub is a compiler-generated
	         stub.  Such a stub for a function bar might have a name
	         like __fn_stub_bar, and might look like this:
	         mfc1    $4,$f13
	         mfc1    $5,$f12
	         mfc1    $6,$f15
	         mfc1    $7,$f14
	         la      $1,bar   (becomes a lui/addiu pair)
	         jr      $1
	         So scan down to the lui/addi and extract the target
	         address from those two instructions.  */

	      CORE_ADDR target_pc = read_register (2);
	      t_inst inst;
	      int i;

	      /* See if the name of the target function is  __fn_stub_*.  */
	      if (find_pc_partial_function (target_pc, &name, NULL, NULL) == 0)
		return target_pc;
	      if (strncmp (name, "__fn_stub_", 10) != 0
		  && strcmp (name, "etext") != 0
		  && strcmp (name, "_etext") != 0)
		return target_pc;

	      /* Scan through this _fn_stub_ code for the lui/addiu pair.
	         The limit on the search is arbitrarily set to 20
	         instructions.  FIXME.  */
	      for (i = 0, pc = 0; i < 20; i++, target_pc += MIPS_INSTLEN)
		{
		  inst = mips_fetch_instruction (target_pc);
		  if ((inst & 0xffff0000) == 0x3c010000)	/* lui $at */
		    pc = (inst << 16) & 0xffff0000;	/* high word */
		  else if ((inst & 0xffff0000) == 0x24210000)	/* addiu $at */
		    return pc | (inst & 0xffff);	/* low word */
		}

	      /* Couldn't find the lui/addui pair, so return stub address.  */
	      return target_pc;
	    }
	  else
	    /* This is the 'return' part of a call stub.  The return
	       address is in $r18.  */
	    return read_register (18);
	}
    }
  return 0;			/* not a stub */
}


/* Return non-zero if the PC is inside a call thunk (aka stub or trampoline).
   This implements the IN_SOLIB_CALL_TRAMPOLINE macro.  */

int
mips_in_call_stub (pc, name)
     CORE_ADDR pc;
     char *name;
{
  CORE_ADDR start_addr;

  /* Find the starting address of the function containing the PC.  If the
     caller didn't give us a name, look it up at the same time.  */
  if (find_pc_partial_function (pc, name ? NULL : &name, &start_addr, NULL) == 0)
    return 0;

  if (strncmp (name, "__mips16_call_stub_", 19) == 0)
    {
      /* If the PC is in __mips16_call_stub_{1..10}, this is a call stub.  */
      if (name[19] >= '0' && name[19] <= '9')
	return 1;
      /* If the PC at the start of __mips16_call_stub_{s,d}f_{0..10}, i.e.
         before the jal instruction, this is effectively a call stub.  */
      else if (name[19] == 's' || name[19] == 'd')
	return pc == start_addr;
    }

  return 0;			/* not a stub */
}


/* Return non-zero if the PC is inside a return thunk (aka stub or trampoline).
   This implements the IN_SOLIB_RETURN_TRAMPOLINE macro.  */

int
mips_in_return_stub (pc, name)
     CORE_ADDR pc;
     char *name;
{
  CORE_ADDR start_addr;

  /* Find the starting address of the function containing the PC.  */
  if (find_pc_partial_function (pc, NULL, &start_addr, NULL) == 0)
    return 0;

  /* If the PC is in __mips16_ret_{d,s}f, this is a return stub.  */
  if (strcmp (name, "__mips16_ret_sf") == 0
      || strcmp (name, "__mips16_ret_df") == 0)
    return 1;

  /* If the PC is in __mips16_call_stub_{s,d}f_{0..10} but not at the start,
     i.e. after the jal instruction, this is effectively a return stub.  */
  if (strncmp (name, "__mips16_call_stub_", 19) == 0
      && (name[19] == 's' || name[19] == 'd')
      && pc != start_addr)
    return 1;

  return 0;			/* not a stub */
}


/* Return non-zero if the PC is in a library helper function that should
   be ignored.  This implements the IGNORE_HELPER_CALL macro.  */

int
mips_ignore_helper (pc)
     CORE_ADDR pc;
{
  char *name;

  /* Find the starting address and name of the function containing the PC.  */
  if (find_pc_partial_function (pc, &name, NULL, NULL) == 0)
    return 0;

  /* If the PC is in __mips16_ret_{d,s}f, this is a library helper function
     that we want to ignore.  */
  return (strcmp (name, "__mips16_ret_sf") == 0
	  || strcmp (name, "__mips16_ret_df") == 0);
}


/* Return a location where we can set a breakpoint that will be hit
   when an inferior function call returns.  This is normally the
   program's entry point.  Executables that don't have an entry
   point (e.g. programs in ROM) should define a symbol __CALL_DUMMY_ADDRESS
   whose address is the location where the breakpoint should be placed.  */

CORE_ADDR
mips_call_dummy_address ()
{
  struct minimal_symbol *sym;

  sym = lookup_minimal_symbol ("__CALL_DUMMY_ADDRESS", NULL, NULL);
  if (sym)
    return SYMBOL_VALUE_ADDRESS (sym);
  else
    return entry_point_address ();
}


void
_initialize_mips_tdep ()
{
  static struct cmd_list_element *mipsfpulist = NULL;
  struct cmd_list_element *c;

  if (!tm_print_insn)		/* Someone may have already set it */
    tm_print_insn = gdb_print_insn_mips;

  /* Let the user turn off floating point and set the fence post for
     heuristic_proc_start.  */

  add_prefix_cmd ("mipsfpu", class_support, set_mipsfpu_command,
		  "Set use of MIPS floating-point coprocessor.",
		  &mipsfpulist, "set mipsfpu ", 0, &setlist);
  add_cmd ("single", class_support, set_mipsfpu_single_command,
	   "Select single-precision MIPS floating-point coprocessor.",
	   &mipsfpulist);
  add_cmd ("double", class_support, set_mipsfpu_double_command,
	   "Select double-precision MIPS floating-point coprocessor .",
	   &mipsfpulist);
  add_alias_cmd ("on", "double", class_support, 1, &mipsfpulist);
  add_alias_cmd ("yes", "double", class_support, 1, &mipsfpulist);
  add_alias_cmd ("1", "double", class_support, 1, &mipsfpulist);
  add_cmd ("none", class_support, set_mipsfpu_none_command,
	   "Select no MIPS floating-point coprocessor.",
	   &mipsfpulist);
  add_alias_cmd ("off", "none", class_support, 1, &mipsfpulist);
  add_alias_cmd ("no", "none", class_support, 1, &mipsfpulist);
  add_alias_cmd ("0", "none", class_support, 1, &mipsfpulist);
  add_cmd ("auto", class_support, set_mipsfpu_auto_command,
	   "Select MIPS floating-point coprocessor automatically.",
	   &mipsfpulist);
  add_cmd ("mipsfpu", class_support, show_mipsfpu_command,
	   "Show current use of MIPS floating-point coprocessor target.",
	   &showlist);

  c = add_set_cmd ("processor", class_support, var_string_noescape,
		   (char *) &tmp_mips_processor_type,
		   "Set the type of MIPS processor in use.\n\
Set this to be able to access processor-type-specific registers.\n\
",
		   &setlist);
  c->function.cfunc = mips_set_processor_type_command;
  c = add_show_from_set (c, &showlist);
  c->function.cfunc = mips_show_processor_type_command;

  tmp_mips_processor_type = strsave (DEFAULT_MIPS_TYPE);
  mips_set_processor_type_command (strsave (DEFAULT_MIPS_TYPE), 0);

  /* We really would like to have both "0" and "unlimited" work, but
     command.c doesn't deal with that.  So make it a var_zinteger
     because the user can always use "999999" or some such for unlimited.  */
  c = add_set_cmd ("heuristic-fence-post", class_support, var_zinteger,
		   (char *) &heuristic_fence_post,
		   "\
Set the distance searched for the start of a function.\n\
If you are debugging a stripped executable, GDB needs to search through the\n\
program for the start of a function.  This command sets the distance of the\n\
search.  The only need to set it is when debugging a stripped executable.",
		   &setlist);
  /* We need to throw away the frame cache when we set this, since it
     might change our ability to get backtraces.  */
  c->function.sfunc = reinit_frame_cache_sfunc;
  add_show_from_set (c, &showlist);

  /* Allow the user to control whether the upper bits of 64-bit
     addresses should be zeroed.  */
  add_show_from_set
    (add_set_cmd ("mask-address", no_class, var_boolean, (char *) &mask_address_p,
		  "Set zeroing of upper 32 bits of 64-bit addresses.\n\
Use \"on\" to enable the masking, and \"off\" to disable it.\n\
Without an argument, zeroing of upper address bits is enabled.", &setlist),
     &showlist);

  /* Allow the user to control the size of 32 bit registers within the
     raw remote packet.  */
  add_show_from_set (add_set_cmd ("remote-mips64-transfers-32bit-regs",
				  class_obscure,
				  var_boolean,
				  (char *)&mips64_transfers_32bit_regs_p, "\
Set compatibility with MIPS targets that transfers 32 and 64 bit quantities.\n\
Use \"on\" to enable backward compatibility with older MIPS 64 GDB+target\n\
that would transfer 32 bits for some registers (e.g. SR, FSR) and\n\
64 bits for others.  Use \"off\" to disable compatibility mode",
				  &setlist),
		     &showlist);
}