summaryrefslogtreecommitdiffstats
path: root/js/src/jit/Ion.cpp
blob: 03965d3d602e71c6d349f9db4f94050905988ba7 (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
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: set ts=8 sts=2 et sw=2 tw=80:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "jit/Ion.h"

#include "mozilla/CheckedInt.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/IntegerPrintfMacros.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/ThreadLocal.h"

#include "gc/GCContext.h"
#include "gc/PublicIterators.h"
#include "jit/AliasAnalysis.h"
#include "jit/AlignmentMaskAnalysis.h"
#include "jit/AutoWritableJitCode.h"
#include "jit/BacktrackingAllocator.h"
#include "jit/BaselineFrame.h"
#include "jit/BaselineJIT.h"
#include "jit/BranchHinting.h"
#include "jit/CodeGenerator.h"
#include "jit/CompileInfo.h"
#include "jit/EdgeCaseAnalysis.h"
#include "jit/EffectiveAddressAnalysis.h"
#include "jit/ExecutableAllocator.h"
#include "jit/FoldLinearArithConstants.h"
#include "jit/InlineScriptTree.h"
#include "jit/InstructionReordering.h"
#include "jit/Invalidation.h"
#include "jit/IonAnalysis.h"
#include "jit/IonCompileTask.h"
#include "jit/IonIC.h"
#include "jit/IonOptimizationLevels.h"
#include "jit/IonScript.h"
#include "jit/JitcodeMap.h"
#include "jit/JitFrames.h"
#include "jit/JitRuntime.h"
#include "jit/JitSpewer.h"
#include "jit/JitZone.h"
#include "jit/LICM.h"
#include "jit/Linker.h"
#include "jit/LIR.h"
#include "jit/Lowering.h"
#include "jit/PerfSpewer.h"
#include "jit/RangeAnalysis.h"
#include "jit/ScalarReplacement.h"
#include "jit/ScriptFromCalleeToken.h"
#include "jit/Sink.h"
#include "jit/ValueNumbering.h"
#include "jit/WarpBuilder.h"
#include "jit/WarpOracle.h"
#include "jit/WasmBCE.h"
#include "js/Printf.h"
#include "js/UniquePtr.h"
#include "util/Memory.h"
#include "util/WindowsWrapper.h"
#include "vm/HelperThreads.h"
#include "vm/Realm.h"
#ifdef MOZ_VTUNE
#  include "vtune/VTuneWrapper.h"
#endif

#include "gc/GC-inl.h"
#include "gc/StableCellHasher-inl.h"
#include "jit/InlineScriptTree-inl.h"
#include "jit/MacroAssembler-inl.h"
#include "jit/SafepointIndex-inl.h"
#include "vm/GeckoProfiler-inl.h"
#include "vm/JSContext-inl.h"
#include "vm/JSScript-inl.h"
#include "vm/Realm-inl.h"

#if defined(ANDROID)
#  include <sys/system_properties.h>
#endif

using mozilla::CheckedInt;
using mozilla::DebugOnly;

using namespace js;
using namespace js::jit;

JitRuntime::~JitRuntime() {
  MOZ_ASSERT(numFinishedOffThreadTasks_ == 0);
  MOZ_ASSERT(ionLazyLinkListSize_ == 0);
  MOZ_ASSERT(ionLazyLinkList_.ref().isEmpty());

  MOZ_ASSERT(ionFreeTaskBatch_.ref().empty());

  // By this point, the jitcode global table should be empty.
  MOZ_ASSERT_IF(jitcodeGlobalTable_, jitcodeGlobalTable_->empty());
  js_delete(jitcodeGlobalTable_.ref());

  // interpreterEntryMap should be cleared out during finishRoots()
  MOZ_ASSERT_IF(interpreterEntryMap_, interpreterEntryMap_->empty());
  js_delete(interpreterEntryMap_.ref());

  js_delete(jitHintsMap_.ref());
}

uint32_t JitRuntime::startTrampolineCode(MacroAssembler& masm) {
  AutoCreatedBy acb(masm, "startTrampolineCode");

  masm.assumeUnreachable("Shouldn't get here");
  masm.flushBuffer();
  masm.haltingAlign(CodeAlignment);
  masm.setFramePushed(0);
  return masm.currentOffset();
}

bool JitRuntime::initialize(JSContext* cx) {
  MOZ_ASSERT(CurrentThreadCanAccessRuntime(cx->runtime()));

  AutoAllocInAtomsZone az(cx);
  JitContext jctx(cx);

  if (!generateTrampolines(cx)) {
    return false;
  }

  if (!generateBaselineICFallbackCode(cx)) {
    return false;
  }

  jitcodeGlobalTable_ = cx->new_<JitcodeGlobalTable>();
  if (!jitcodeGlobalTable_) {
    return false;
  }

  if (!JitOptions.disableJitHints) {
    jitHintsMap_ = cx->new_<JitHintsMap>();
    if (!jitHintsMap_) {
      return false;
    }
  }

  if (JitOptions.emitInterpreterEntryTrampoline) {
    interpreterEntryMap_ = cx->new_<EntryTrampolineMap>();
    if (!interpreterEntryMap_) {
      return false;
    }
  }

  if (!GenerateBaselineInterpreter(cx, baselineInterpreter_)) {
    return false;
  }

  // Initialize the jitCodeRaw of the Runtime's canonical SelfHostedLazyScript
  // to point to the interpreter trampoline.
  cx->runtime()->selfHostedLazyScript.ref().jitCodeRaw_ =
      interpreterStub().value;

  return true;
}

bool JitRuntime::generateTrampolines(JSContext* cx) {
  TempAllocator temp(&cx->tempLifoAlloc());
  StackMacroAssembler masm(cx, temp);
  PerfSpewerRangeRecorder rangeRecorder(masm);

  Label bailoutTail;
  JitSpew(JitSpew_Codegen, "# Emitting bailout tail stub");
  generateBailoutTailStub(masm, &bailoutTail);

  JitSpew(JitSpew_Codegen, "# Emitting bailout handler");
  generateBailoutHandler(masm, &bailoutTail);
  rangeRecorder.recordOffset("Trampoline: Bailout");

  JitSpew(JitSpew_Codegen, "# Emitting invalidator");
  generateInvalidator(masm, &bailoutTail);
  rangeRecorder.recordOffset("Trampoline: Invalidator");

  // The arguments rectifier has to use the same frame layout as the function
  // frames it rectifies.
  static_assert(std::is_base_of_v<JitFrameLayout, RectifierFrameLayout>,
                "a rectifier frame can be used with jit frame");
  static_assert(std::is_base_of_v<JitFrameLayout, WasmToJSJitFrameLayout>,
                "wasm frames simply are jit frames");
  static_assert(sizeof(JitFrameLayout) == sizeof(WasmToJSJitFrameLayout),
                "thus a rectifier frame can be used with a wasm frame");

  JitSpew(JitSpew_Codegen, "# Emitting arguments rectifier");
  generateArgumentsRectifier(masm, ArgumentsRectifierKind::Normal);
  rangeRecorder.recordOffset("Trampoline: Arguments Rectifier");

  JitSpew(JitSpew_Codegen, "# Emitting trial inlining arguments rectifier");
  generateArgumentsRectifier(masm, ArgumentsRectifierKind::TrialInlining);
  rangeRecorder.recordOffset(
      "Trampoline: Arguments Rectifier (Trial Inlining)");

  JitSpew(JitSpew_Codegen, "# Emitting EnterJIT sequence");
  generateEnterJIT(cx, masm);
  rangeRecorder.recordOffset("Trampoline: EnterJIT");

  JitSpew(JitSpew_Codegen, "# Emitting Pre Barrier for Value");
  valuePreBarrierOffset_ = generatePreBarrier(cx, masm, MIRType::Value);
  rangeRecorder.recordOffset("Trampoline: PreBarrier Value");

  JitSpew(JitSpew_Codegen, "# Emitting Pre Barrier for String");
  stringPreBarrierOffset_ = generatePreBarrier(cx, masm, MIRType::String);
  rangeRecorder.recordOffset("Trampoline: PreBarrier String");

  JitSpew(JitSpew_Codegen, "# Emitting Pre Barrier for Object");
  objectPreBarrierOffset_ = generatePreBarrier(cx, masm, MIRType::Object);
  rangeRecorder.recordOffset("Trampoline: PreBarrier Object");

  JitSpew(JitSpew_Codegen, "# Emitting Pre Barrier for Shape");
  shapePreBarrierOffset_ = generatePreBarrier(cx, masm, MIRType::Shape);
  rangeRecorder.recordOffset("Trampoline: PreBarrier Shape");

  JitSpew(JitSpew_Codegen, "# Emitting Pre Barrier for WasmAnyRef");
  wasmAnyRefPreBarrierOffset_ =
      generatePreBarrier(cx, masm, MIRType::WasmAnyRef);
  rangeRecorder.recordOffset("Trampoline: PreBarrier WasmAnyRef");

  JitSpew(JitSpew_Codegen, "# Emitting free stub");
  generateFreeStub(masm);
  rangeRecorder.recordOffset("Trampoline: FreeStub");

  JitSpew(JitSpew_Codegen, "# Emitting lazy link stub");
  generateLazyLinkStub(masm);
  rangeRecorder.recordOffset("Trampoline: LazyLinkStub");

  JitSpew(JitSpew_Codegen, "# Emitting interpreter stub");
  generateInterpreterStub(masm);
  rangeRecorder.recordOffset("Trampoline: Interpreter");

  JitSpew(JitSpew_Codegen, "# Emitting double-to-int32-value stub");
  generateDoubleToInt32ValueStub(masm);
  rangeRecorder.recordOffset("Trampoline: DoubleToInt32ValueStub");

  JitSpew(JitSpew_Codegen, "# Emitting VM function wrappers");
  if (!generateVMWrappers(cx, masm, rangeRecorder)) {
    return false;
  }

  JitSpew(JitSpew_Codegen, "# Emitting profiler exit frame tail stub");
  Label profilerExitTail;
  generateProfilerExitFrameTailStub(masm, &profilerExitTail);
  rangeRecorder.recordOffset("Trampoline: ProfilerExitFrameTailStub");

  JitSpew(JitSpew_Codegen, "# Emitting exception tail stub");
  generateExceptionTailStub(masm, &profilerExitTail, &bailoutTail);
  rangeRecorder.recordOffset("Trampoline: ExceptionTailStub");

  JitSpew(JitSpew_Codegen, "# Emitting Ion generic call stub");
  generateIonGenericCallStub(masm, IonGenericCallKind::Call);
  rangeRecorder.recordOffset("Trampoline: IonGenericCall");

  JitSpew(JitSpew_Codegen, "# Emitting Ion generic construct stub");
  generateIonGenericCallStub(masm, IonGenericCallKind::Construct);
  rangeRecorder.recordOffset("Trampoline: IonGenericConstruct");

  JitSpew(JitSpew_Codegen, "# Emitting trampoline natives");
  TrampolineNativeJitEntryOffsets nativeOffsets;
  generateTrampolineNatives(masm, nativeOffsets, rangeRecorder);

  Linker linker(masm);
  trampolineCode_ = linker.newCode(cx, CodeKind::Other);
  if (!trampolineCode_) {
    return false;
  }

  rangeRecorder.collectRangesForJitCode(trampolineCode_);
#ifdef MOZ_VTUNE
  vtune::MarkStub(trampolineCode_, "Trampolines");
#endif

  // Initialize TrampolineNative JitEntry array.
  for (size_t i = 0; i < size_t(TrampolineNative::Count); i++) {
    TrampolineNative native = TrampolineNative(i);
    uint32_t offset = nativeOffsets[native];
    MOZ_ASSERT(offset > 0 && offset < trampolineCode_->instructionsSize());
    trampolineNativeJitEntries_[native] = trampolineCode_->raw() + offset;
  }

  return true;
}

JitCode* JitRuntime::debugTrapHandler(JSContext* cx,
                                      DebugTrapHandlerKind kind) {
  if (!debugTrapHandlers_[kind]) {
    // JitRuntime code stubs are shared across compartments and have to
    // be allocated in the atoms zone.
    mozilla::Maybe<AutoAllocInAtomsZone> az;
    if (!cx->zone()->isAtomsZone()) {
      az.emplace(cx);
    }
    debugTrapHandlers_[kind] = generateDebugTrapHandler(cx, kind);
  }
  return debugTrapHandlers_[kind];
}

JitRuntime::IonCompileTaskList& JitRuntime::ionLazyLinkList(JSRuntime* rt) {
  MOZ_ASSERT(CurrentThreadCanAccessRuntime(rt),
             "Should only be mutated by the main thread.");
  return ionLazyLinkList_.ref();
}

void JitRuntime::ionLazyLinkListRemove(JSRuntime* rt,
                                       jit::IonCompileTask* task) {
  MOZ_ASSERT(CurrentThreadCanAccessRuntime(rt),
             "Should only be mutated by the main thread.");
  MOZ_ASSERT(rt == task->script()->runtimeFromMainThread());
  MOZ_ASSERT(ionLazyLinkListSize_ > 0);

  task->removeFrom(ionLazyLinkList(rt));
  ionLazyLinkListSize_--;

  MOZ_ASSERT(ionLazyLinkList(rt).isEmpty() == (ionLazyLinkListSize_ == 0));
}

void JitRuntime::ionLazyLinkListAdd(JSRuntime* rt, jit::IonCompileTask* task) {
  MOZ_ASSERT(CurrentThreadCanAccessRuntime(rt),
             "Should only be mutated by the main thread.");
  MOZ_ASSERT(rt == task->script()->runtimeFromMainThread());
  ionLazyLinkList(rt).insertFront(task);
  ionLazyLinkListSize_++;
}

uint8_t* JitRuntime::allocateIonOsrTempData(size_t size) {
  MOZ_ASSERT(size > 0);

  uint8_t* prevBuffer = ionOsrTempData_.ref().get();
  size_t prevSize = ionOsrTempDataSize_.ref();
  MOZ_ASSERT((prevSize > 0) == !!prevBuffer);

  // Reuse the previous buffer if possible.
  if (prevSize >= size) {
    return prevBuffer;
  }

  // Allocate or resize the buffer.
  uint8_t* buffer = js_pod_realloc<uint8_t>(prevBuffer, prevSize, size);
  if (!buffer) {
    // ionOsrTempData_ is still valid.
    return nullptr;
  }
  // ionOsrTempData_ is no longer valid.
  (void)ionOsrTempData_.ref().release();
  ionOsrTempData_.ref().reset(buffer);
  ionOsrTempDataSize_ = size;
  return buffer;
}

void JitRuntime::freeIonOsrTempData() {
  ionOsrTempData_.ref().reset();
  ionOsrTempDataSize_ = 0;
}

template <typename T>
static T PopNextBitmaskValue(uint32_t* bitmask) {
  MOZ_ASSERT(*bitmask);
  uint32_t index = mozilla::CountTrailingZeroes32(*bitmask);
  *bitmask ^= 1 << index;

  MOZ_ASSERT(index < uint32_t(T::Count));
  return T(index);
}

void JitZone::performStubReadBarriers(uint32_t stubsToBarrier) const {
  while (stubsToBarrier) {
    auto stub = PopNextBitmaskValue<StubIndex>(&stubsToBarrier);
    const WeakHeapPtr<JitCode*>& jitCode = stubs_[stub];
    MOZ_ASSERT(jitCode);
    jitCode.get();
  }
}

static bool LinkCodeGen(JSContext* cx, CodeGenerator* codegen,
                        HandleScript script, const WarpSnapshot* snapshot) {
  if (!codegen->link(cx, snapshot)) {
    return false;
  }

  return true;
}

static bool LinkBackgroundCodeGen(JSContext* cx, IonCompileTask* task) {
  CodeGenerator* codegen = task->backgroundCodegen();
  if (!codegen) {
    return false;
  }

  JitContext jctx(cx);
  RootedScript script(cx, task->script());
  return LinkCodeGen(cx, codegen, script, task->snapshot());
}

void jit::LinkIonScript(JSContext* cx, HandleScript calleeScript) {
  // Get the pending IonCompileTask from the script.
  MOZ_ASSERT(calleeScript->hasBaselineScript());
  IonCompileTask* task =
      calleeScript->baselineScript()->pendingIonCompileTask();
  calleeScript->baselineScript()->removePendingIonCompileTask(cx->runtime(),
                                                              calleeScript);

  // Remove from pending.
  cx->runtime()->jitRuntime()->ionLazyLinkListRemove(cx->runtime(), task);

  {
    gc::AutoSuppressGC suppressGC(cx);
    if (!LinkBackgroundCodeGen(cx, task)) {
      // Silently ignore OOM during code generation. The assembly code
      // doesn't have code to handle it after linking happened. So it's
      // not OK to throw a catchable exception from there.
      cx->clearPendingException();
    }
  }

  AutoStartIonFreeTask freeTask(cx->runtime()->jitRuntime());
  FinishOffThreadTask(cx->runtime(), freeTask, task);
}

uint8_t* jit::LazyLinkTopActivation(JSContext* cx,
                                    LazyLinkExitFrameLayout* frame) {
  RootedScript calleeScript(
      cx, ScriptFromCalleeToken(frame->jsFrame()->calleeToken()));

  LinkIonScript(cx, calleeScript);

  MOZ_ASSERT(calleeScript->hasBaselineScript());
  MOZ_ASSERT(calleeScript->jitCodeRaw());

  return calleeScript->jitCodeRaw();
}

/* static */
void JitRuntime::TraceAtomZoneRoots(JSTracer* trc) {
  MOZ_ASSERT(!JS::RuntimeHeapIsMinorCollecting());

  // Shared stubs are allocated in the atoms zone, so do not iterate
  // them after the atoms heap after it has been "finished."
  if (trc->runtime()->atomsAreFinished()) {
    return;
  }

  Zone* zone = trc->runtime()->atomsZone();
  for (auto i = zone->cellIterUnsafe<JitCode>(); !i.done(); i.next()) {
    JitCode* code = i;
    TraceRoot(trc, &code, "wrapper");
  }
}

/* static */
bool JitRuntime::MarkJitcodeGlobalTableIteratively(GCMarker* marker) {
  if (marker->runtime()->hasJitRuntime() &&
      marker->runtime()->jitRuntime()->hasJitcodeGlobalTable()) {
    return marker->runtime()
        ->jitRuntime()
        ->getJitcodeGlobalTable()
        ->markIteratively(marker);
  }
  return false;
}

/* static */
void JitRuntime::TraceWeakJitcodeGlobalTable(JSRuntime* rt, JSTracer* trc) {
  if (rt->hasJitRuntime() && rt->jitRuntime()->hasJitcodeGlobalTable()) {
    rt->jitRuntime()->getJitcodeGlobalTable()->traceWeak(rt, trc);
  }
}

bool JitZone::addInlinedCompilation(const RecompileInfo& info,
                                    JSScript* inlined) {
  MOZ_ASSERT(inlined != info.script());

  auto p = inlinedCompilations_.lookupForAdd(inlined);
  if (p) {
    auto& compilations = p->value();
    if (!compilations.empty() && compilations.back() == info) {
      return true;
    }
    return compilations.append(info);
  }

  RecompileInfoVector compilations;
  if (!compilations.append(info)) {
    return false;
  }
  return inlinedCompilations_.add(p, inlined, std::move(compilations));
}

void jit::AddPendingInvalidation(RecompileInfoVector& invalid,
                                 JSScript* script) {
  MOZ_ASSERT(script);

  CancelOffThreadIonCompile(script);

  // Let the script warm up again before attempting another compile.
  script->resetWarmUpCounterToDelayIonCompilation();

  JitScript* jitScript = script->maybeJitScript();
  if (!jitScript) {
    return;
  }

  auto addPendingInvalidation = [&invalid](const RecompileInfo& info) {
    AutoEnterOOMUnsafeRegion oomUnsafe;
    if (!invalid.append(info)) {
      // BUG 1536159: For diagnostics, compute the size of the failed
      // allocation. This presumes the vector growth strategy is to double. This
      // is only used for crash reporting so not a problem if we get it wrong.
      size_t allocSize = 2 * sizeof(RecompileInfo) * invalid.capacity();
      oomUnsafe.crash(allocSize, "Could not update RecompileInfoVector");
    }
  };

  // Trigger invalidation of the IonScript.
  if (jitScript->hasIonScript()) {
    RecompileInfo info(script, jitScript->ionScript()->compilationId());
    addPendingInvalidation(info);
  }

  // Trigger invalidation of any callers inlining this script.
  auto* inlinedCompilations =
      script->zone()->jitZone()->maybeInlinedCompilations(script);
  if (inlinedCompilations) {
    for (const RecompileInfo& info : *inlinedCompilations) {
      addPendingInvalidation(info);
    }
    script->zone()->jitZone()->removeInlinedCompilations(script);
  }
}

IonScript* RecompileInfo::maybeIonScriptToInvalidate() const {
  // Make sure this is not called under CodeGenerator::link (before the
  // IonScript is created).
  MOZ_ASSERT_IF(
      script_->zone()->jitZone()->currentCompilationId(),
      script_->zone()->jitZone()->currentCompilationId().ref() != id_);

  if (!script_->hasIonScript() ||
      script_->ionScript()->compilationId() != id_) {
    return nullptr;
  }

  return script_->ionScript();
}

bool RecompileInfo::traceWeak(JSTracer* trc) {
  // Sweep the RecompileInfo if either the script is dead or the IonScript has
  // been invalidated.

  if (!TraceManuallyBarrieredWeakEdge(trc, &script_, "RecompileInfo::script")) {
    return false;
  }

  return maybeIonScriptToInvalidate() != nullptr;
}

void JitZone::traceWeak(JSTracer* trc, Zone* zone) {
  MOZ_ASSERT(this == zone->jitZone());

  // Any outstanding compilations should have been cancelled by the GC.
  MOZ_ASSERT(!HasOffThreadIonCompile(zone));

  for (WeakHeapPtr<JitCode*>& stub : stubs_) {
    TraceWeakEdge(trc, &stub, "JitZone::stubs_");
  }

  baselineCacheIRStubCodes_.traceWeak(trc);
  inlinedCompilations_.traceWeak(trc);

  TraceWeakEdge(trc, &lastStubFoldingBailoutChild_,
                "JitZone::lastStubFoldingBailoutChild_");
  TraceWeakEdge(trc, &lastStubFoldingBailoutParent_,
                "JitZone::lastStubFoldingBailoutParent_");
}

void JitZone::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf,
                                     JS::CodeSizes* code, size_t* jitZone,
                                     size_t* cacheIRStubs) const {
  *jitZone += mallocSizeOf(this);
  *jitZone +=
      baselineCacheIRStubCodes_.shallowSizeOfExcludingThis(mallocSizeOf);
  *jitZone += ionCacheIRStubInfoSet_.shallowSizeOfExcludingThis(mallocSizeOf);

  execAlloc().addSizeOfCode(code);

  *cacheIRStubs += stubSpace_.sizeOfExcludingThis(mallocSizeOf);
}

void JitCodeHeader::init(JitCode* jitCode) {
  // As long as JitCode isn't moveable, we can avoid tracing this and
  // mutating executable data.
  MOZ_ASSERT(!gc::IsMovableKind(gc::AllocKind::JITCODE));
  jitCode_ = jitCode;
}

template <AllowGC allowGC>
JitCode* JitCode::New(JSContext* cx, uint8_t* code, uint32_t totalSize,
                      uint32_t headerSize, ExecutablePool* pool,
                      CodeKind kind) {
  uint32_t bufferSize = totalSize - headerSize;
  JitCode* codeObj =
      cx->newCell<JitCode, allowGC>(code, bufferSize, headerSize, pool, kind);
  if (!codeObj) {
    // The caller already allocated `totalSize` bytes of executable memory.
    pool->release(totalSize, kind);
    return nullptr;
  }

  cx->zone()->incJitMemory(totalSize);

  return codeObj;
}

template JitCode* JitCode::New<CanGC>(JSContext* cx, uint8_t* code,
                                      uint32_t bufferSize, uint32_t headerSize,
                                      ExecutablePool* pool, CodeKind kind);

template JitCode* JitCode::New<NoGC>(JSContext* cx, uint8_t* code,
                                     uint32_t bufferSize, uint32_t headerSize,
                                     ExecutablePool* pool, CodeKind kind);

void JitCode::copyFrom(MacroAssembler& masm) {
  // Store the JitCode pointer in the JitCodeHeader so we can recover the
  // gcthing from relocation tables.
  JitCodeHeader::FromExecutable(raw())->init(this);

  insnSize_ = masm.instructionsSize();
  masm.executableCopy(raw());

  jumpRelocTableBytes_ = masm.jumpRelocationTableBytes();
  masm.copyJumpRelocationTable(raw() + jumpRelocTableOffset());

  dataRelocTableBytes_ = masm.dataRelocationTableBytes();
  masm.copyDataRelocationTable(raw() + dataRelocTableOffset());

  masm.processCodeLabels(raw());
}

void JitCode::traceChildren(JSTracer* trc) {
  // Note that we cannot mark invalidated scripts, since we've basically
  // corrupted the code stream by injecting bailouts.
  if (invalidated()) {
    return;
  }

  if (jumpRelocTableBytes_) {
    uint8_t* start = raw() + jumpRelocTableOffset();
    CompactBufferReader reader(start, start + jumpRelocTableBytes_);
    MacroAssembler::TraceJumpRelocations(trc, this, reader);
  }
  if (dataRelocTableBytes_) {
    uint8_t* start = raw() + dataRelocTableOffset();
    CompactBufferReader reader(start, start + dataRelocTableBytes_);
    MacroAssembler::TraceDataRelocations(trc, this, reader);
  }
}

void JitCode::finalize(JS::GCContext* gcx) {
  // If this jitcode had a bytecode map, it must have already been removed.
#ifdef DEBUG
  JSRuntime* rt = gcx->runtime();
  if (hasBytecodeMap_) {
    MOZ_ASSERT(rt->jitRuntime()->hasJitcodeGlobalTable());
    MOZ_ASSERT(!rt->jitRuntime()->getJitcodeGlobalTable()->lookup(raw()));
  }
#endif

#ifdef MOZ_VTUNE
  vtune::UnmarkCode(this);
#endif

  MOZ_ASSERT(pool_);

  // With W^X JIT code, reprotecting memory for each JitCode instance is
  // slow, so we record the ranges and poison them later all at once. It's
  // safe to ignore OOM here, it just means we won't poison the code.
  if (gcx->appendJitPoisonRange(JitPoisonRange(pool_, raw() - headerSize_,
                                               headerSize_ + bufferSize_))) {
    pool_->addRef();
  }
  setHeaderPtr(nullptr);

#ifdef JS_ION_PERF
  // Code buffers are stored inside ExecutablePools. Pools are refcounted.
  // Releasing the pool may free it. Horrible hack: if we are using perf
  // integration, we don't want to reuse code addresses, so we just leak the
  // memory instead.
  if (!PerfEnabled()) {
    pool_->release(headerSize_ + bufferSize_, CodeKind(kind_));
  }
#else
  pool_->release(headerSize_ + bufferSize_, CodeKind(kind_));
#endif

  zone()->decJitMemory(headerSize_ + bufferSize_);

  pool_ = nullptr;
}

IonScript::IonScript(IonCompilationId compilationId, uint32_t localSlotsSize,
                     uint32_t argumentSlotsSize, uint32_t frameSize)
    : localSlotsSize_(localSlotsSize),
      argumentSlotsSize_(argumentSlotsSize),
      frameSize_(frameSize),
      compilationId_(compilationId) {}

IonScript* IonScript::New(JSContext* cx, IonCompilationId compilationId,
                          uint32_t localSlotsSize, uint32_t argumentSlotsSize,
                          uint32_t frameSize, size_t snapshotsListSize,
                          size_t snapshotsRVATableSize, size_t recoversSize,
                          size_t constants, size_t nurseryObjects,
                          size_t safepointIndices, size_t osiIndices,
                          size_t icEntries, size_t runtimeSize,
                          size_t safepointsSize) {
  if (snapshotsListSize >= MAX_BUFFER_SIZE) {
    ReportOutOfMemory(cx);
    return nullptr;
  }

  // Verify the hardcoded sizes in header are accurate.
  static_assert(SizeOf_OsiIndex == sizeof(OsiIndex),
                "IonScript has wrong size for OsiIndex");
  static_assert(SizeOf_SafepointIndex == sizeof(SafepointIndex),
                "IonScript has wrong size for SafepointIndex");

  CheckedInt<Offset> allocSize = sizeof(IonScript);
  allocSize += CheckedInt<Offset>(constants) * sizeof(Value);
  allocSize += CheckedInt<Offset>(runtimeSize);
  allocSize += CheckedInt<Offset>(nurseryObjects) * sizeof(HeapPtr<JSObject*>);
  allocSize += CheckedInt<Offset>(osiIndices) * sizeof(OsiIndex);
  allocSize += CheckedInt<Offset>(safepointIndices) * sizeof(SafepointIndex);
  allocSize += CheckedInt<Offset>(icEntries) * sizeof(uint32_t);
  allocSize += CheckedInt<Offset>(safepointsSize);
  allocSize += CheckedInt<Offset>(snapshotsListSize);
  allocSize += CheckedInt<Offset>(snapshotsRVATableSize);
  allocSize += CheckedInt<Offset>(recoversSize);

  if (!allocSize.isValid()) {
    ReportAllocationOverflow(cx);
    return nullptr;
  }

  void* raw = cx->pod_malloc<uint8_t>(allocSize.value());
  MOZ_ASSERT(uintptr_t(raw) % alignof(IonScript) == 0);
  if (!raw) {
    return nullptr;
  }
  IonScript* script = new (raw)
      IonScript(compilationId, localSlotsSize, argumentSlotsSize, frameSize);

  Offset offsetCursor = sizeof(IonScript);

  MOZ_ASSERT(offsetCursor % alignof(Value) == 0);
  script->constantTableOffset_ = offsetCursor;
  offsetCursor += constants * sizeof(Value);

  MOZ_ASSERT(offsetCursor % alignof(uint64_t) == 0);
  script->runtimeDataOffset_ = offsetCursor;
  offsetCursor += runtimeSize;

  MOZ_ASSERT(offsetCursor % alignof(HeapPtr<JSObject*>) == 0);
  script->initElements<HeapPtr<JSObject*>>(offsetCursor, nurseryObjects);
  script->nurseryObjectsOffset_ = offsetCursor;
  offsetCursor += nurseryObjects * sizeof(HeapPtr<JSObject*>);

  MOZ_ASSERT(offsetCursor % alignof(OsiIndex) == 0);
  script->osiIndexOffset_ = offsetCursor;
  offsetCursor += osiIndices * sizeof(OsiIndex);

  MOZ_ASSERT(offsetCursor % alignof(SafepointIndex) == 0);
  script->safepointIndexOffset_ = offsetCursor;
  offsetCursor += safepointIndices * sizeof(SafepointIndex);

  MOZ_ASSERT(offsetCursor % alignof(uint32_t) == 0);
  script->icIndexOffset_ = offsetCursor;
  offsetCursor += icEntries * sizeof(uint32_t);

  script->safepointsOffset_ = offsetCursor;
  offsetCursor += safepointsSize;

  script->snapshotsOffset_ = offsetCursor;
  offsetCursor += snapshotsListSize;

  script->rvaTableOffset_ = offsetCursor;
  offsetCursor += snapshotsRVATableSize;

  script->recoversOffset_ = offsetCursor;
  offsetCursor += recoversSize;

  script->allocBytes_ = offsetCursor;

  MOZ_ASSERT(script->numConstants() == constants);
  MOZ_ASSERT(script->runtimeSize() == runtimeSize);
  MOZ_ASSERT(script->numNurseryObjects() == nurseryObjects);
  MOZ_ASSERT(script->numOsiIndices() == osiIndices);
  MOZ_ASSERT(script->numSafepointIndices() == safepointIndices);
  MOZ_ASSERT(script->numICs() == icEntries);
  MOZ_ASSERT(script->safepointsSize() == safepointsSize);
  MOZ_ASSERT(script->snapshotsListSize() == snapshotsListSize);
  MOZ_ASSERT(script->snapshotsRVATableSize() == snapshotsRVATableSize);
  MOZ_ASSERT(script->recoversSize() == recoversSize);
  MOZ_ASSERT(script->endOffset() == offsetCursor);

  return script;
}

void IonScript::trace(JSTracer* trc) {
  if (method_) {
    TraceEdge(trc, &method_, "method");
  }

  for (size_t i = 0; i < numConstants(); i++) {
    TraceEdge(trc, &getConstant(i), "constant");
  }

  for (size_t i = 0; i < numNurseryObjects(); i++) {
    TraceEdge(trc, &nurseryObjects()[i], "nursery-object");
  }

  // Trace caches so that the JSScript pointer can be updated if moved.
  for (size_t i = 0; i < numICs(); i++) {
    getICFromIndex(i).trace(trc, this);
  }
}

void IonScript::traceWeak(JSTracer* trc) {
  // IonICs do not currently contain weak pointers. If this is added then they
  // should be traced here.
}

/* static */
void IonScript::preWriteBarrier(Zone* zone, IonScript* ionScript) {
  PreWriteBarrier(zone, ionScript);
}

void IonScript::copySnapshots(const SnapshotWriter* writer) {
  MOZ_ASSERT(writer->listSize() == snapshotsListSize());
  memcpy(offsetToPointer<uint8_t>(snapshotsOffset()), writer->listBuffer(),
         snapshotsListSize());

  MOZ_ASSERT(snapshotsRVATableSize());
  MOZ_ASSERT(writer->RVATableSize() == snapshotsRVATableSize());
  memcpy(offsetToPointer<uint8_t>(rvaTableOffset()), writer->RVATableBuffer(),
         snapshotsRVATableSize());
}

void IonScript::copyRecovers(const RecoverWriter* writer) {
  MOZ_ASSERT(writer->size() == recoversSize());
  memcpy(offsetToPointer<uint8_t>(recoversOffset()), writer->buffer(),
         recoversSize());
}

void IonScript::copySafepoints(const SafepointWriter* writer) {
  MOZ_ASSERT(writer->size() == safepointsSize());
  memcpy(offsetToPointer<uint8_t>(safepointsOffset()), writer->buffer(),
         safepointsSize());
}

void IonScript::copyConstants(const Value* vp) {
  for (size_t i = 0; i < numConstants(); i++) {
    constants()[i].init(vp[i]);
  }
}

void IonScript::copySafepointIndices(const CodegenSafepointIndex* si) {
  // Convert CodegenSafepointIndex to more compact form.
  SafepointIndex* table = safepointIndices();
  for (size_t i = 0; i < numSafepointIndices(); ++i) {
    table[i] = SafepointIndex(si[i]);
  }
}

void IonScript::copyOsiIndices(const OsiIndex* oi) {
  memcpy(osiIndices(), oi, numOsiIndices() * sizeof(OsiIndex));
}

void IonScript::copyRuntimeData(const uint8_t* data) {
  memcpy(runtimeData(), data, runtimeSize());
}

void IonScript::copyICEntries(const uint32_t* icEntries) {
  memcpy(icIndex(), icEntries, numICs() * sizeof(uint32_t));

  // Update the codeRaw_ field in the ICs now that we know the code address.
  for (size_t i = 0; i < numICs(); i++) {
    getICFromIndex(i).resetCodeRaw(this);
  }
}

const SafepointIndex* IonScript::getSafepointIndex(uint32_t disp) const {
  MOZ_ASSERT(numSafepointIndices() > 0);

  const SafepointIndex* table = safepointIndices();
  if (numSafepointIndices() == 1) {
    MOZ_ASSERT(disp == table[0].displacement());
    return &table[0];
  }

  size_t minEntry = 0;
  size_t maxEntry = numSafepointIndices() - 1;
  uint32_t min = table[minEntry].displacement();
  uint32_t max = table[maxEntry].displacement();

  // Raise if the element is not in the list.
  MOZ_ASSERT(min <= disp && disp <= max);

  // Approximate the location of the FrameInfo.
  size_t guess = (disp - min) * (maxEntry - minEntry) / (max - min) + minEntry;
  uint32_t guessDisp = table[guess].displacement();

  if (table[guess].displacement() == disp) {
    return &table[guess];
  }

  // Doing a linear scan from the guess should be more efficient in case of
  // small group which are equally distributed on the code.
  //
  // such as:  <...      ...    ...  ...  .   ...    ...>
  if (guessDisp > disp) {
    while (--guess >= minEntry) {
      guessDisp = table[guess].displacement();
      MOZ_ASSERT(guessDisp >= disp);
      if (guessDisp == disp) {
        return &table[guess];
      }
    }
  } else {
    while (++guess <= maxEntry) {
      guessDisp = table[guess].displacement();
      MOZ_ASSERT(guessDisp <= disp);
      if (guessDisp == disp) {
        return &table[guess];
      }
    }
  }

  MOZ_CRASH("displacement not found.");
}

const OsiIndex* IonScript::getOsiIndex(uint32_t disp) const {
  const OsiIndex* end = osiIndices() + numOsiIndices();
  for (const OsiIndex* it = osiIndices(); it != end; ++it) {
    if (it->returnPointDisplacement() == disp) {
      return it;
    }
  }

  MOZ_CRASH("Failed to find OSI point return address");
}

const OsiIndex* IonScript::getOsiIndex(uint8_t* retAddr) const {
  JitSpew(JitSpew_IonInvalidate, "IonScript %p has method %p raw %p",
          (void*)this, (void*)method(), method()->raw());

  MOZ_ASSERT(containsCodeAddress(retAddr));
  uint32_t disp = retAddr - method()->raw();
  return getOsiIndex(disp);
}

void IonScript::Destroy(JS::GCContext* gcx, IonScript* script) {
  // Make sure there are no pointers into the IonScript's nursery objects list
  // in the store buffer. Because this can be called during sweeping when
  // discarding JIT code, we have to lock the store buffer when we find an
  // object that's (still) in the nursery.
  mozilla::Maybe<gc::AutoLockStoreBuffer> lock;
  for (size_t i = 0, len = script->numNurseryObjects(); i < len; i++) {
    JSObject* obj = script->nurseryObjects()[i];
    if (!IsInsideNursery(obj)) {
      continue;
    }
    if (lock.isNothing()) {
      lock.emplace(gcx->runtimeFromAnyThread());
    }
    script->nurseryObjects()[i] = HeapPtr<JSObject*>();
  }

  // This allocation is tracked by JSScript::setIonScriptImpl.
  gcx->deleteUntracked(script);
}

void JS::DeletePolicy<js::jit::IonScript>::operator()(
    const js::jit::IonScript* script) {
  IonScript::Destroy(rt_->gcContext(), const_cast<IonScript*>(script));
}

void IonScript::purgeICs(Zone* zone) {
  for (size_t i = 0; i < numICs(); i++) {
    getICFromIndex(i).reset(zone, this);
  }
}

namespace js {
namespace jit {

bool OptimizeMIR(MIRGenerator* mir) {
  MIRGraph& graph = mir->graph();
  GraphSpewer& gs = mir->graphSpewer();

  if (mir->shouldCancel("Start")) {
    return false;
  }

  gs.spewPass("BuildSSA");
  AssertBasicGraphCoherency(graph);

  if (JitSpewEnabled(JitSpew_MIRExpressions)) {
    JitSpewCont(JitSpew_MIRExpressions, "\n");
    DumpMIRExpressions(JitSpewPrinter(), graph, mir->outerInfo(),
                       "BuildSSA (== input to OptimizeMIR)");
  }

  if (!JitOptions.disablePruning && !mir->compilingWasm()) {
    JitSpewCont(JitSpew_Prune, "\n");
    if (!PruneUnusedBranches(mir, graph)) {
      return false;
    }
    gs.spewPass("Prune Unused Branches");
    AssertBasicGraphCoherency(graph);

    if (mir->shouldCancel("Prune Unused Branches")) {
      return false;
    }
  }

  {
    if (!FoldEmptyBlocks(graph)) {
      return false;
    }
    gs.spewPass("Fold Empty Blocks");
    AssertBasicGraphCoherency(graph);

    if (mir->shouldCancel("Fold Empty Blocks")) {
      return false;
    }
  }

  // Remove trivially dead resume point operands before folding tests, so the
  // latter pass can optimize more aggressively.
  if (!mir->compilingWasm()) {
    if (!EliminateTriviallyDeadResumePointOperands(mir, graph)) {
      return false;
    }
    gs.spewPass("Eliminate trivially dead resume point operands");
    AssertBasicGraphCoherency(graph);

    if (mir->shouldCancel("Eliminate trivially dead resume point operands")) {
      return false;
    }
  }

  {
    if (!FoldTests(graph)) {
      return false;
    }
    gs.spewPass("Fold Tests");
    AssertBasicGraphCoherency(graph);

    if (mir->shouldCancel("Fold Tests")) {
      return false;
    }
  }

  {
    if (!SplitCriticalEdges(graph)) {
      return false;
    }
    gs.spewPass("Split Critical Edges");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("Split Critical Edges")) {
      return false;
    }
  }

  {
    RenumberBlocks(graph);
    gs.spewPass("Renumber Blocks");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("Renumber Blocks")) {
      return false;
    }
  }

  {
    if (!BuildDominatorTree(graph)) {
      return false;
    }
    // No spew: graph not changed.

    if (mir->shouldCancel("Dominator Tree")) {
      return false;
    }
  }

  {
    // Aggressive phi elimination must occur before any code elimination. If the
    // script contains a try-statement, we only compiled the try block and not
    // the catch or finally blocks, so in this case it's also invalid to use
    // aggressive phi elimination.
    Observability observability = graph.hasTryBlock()
                                      ? ConservativeObservability
                                      : AggressiveObservability;
    if (!EliminatePhis(mir, graph, observability)) {
      return false;
    }
    gs.spewPass("Eliminate phis");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("Eliminate phis")) {
      return false;
    }

    if (!BuildPhiReverseMapping(graph)) {
      return false;
    }
    AssertExtendedGraphCoherency(graph);
    // No spew: graph not changed.

    if (mir->shouldCancel("Phi reverse mapping")) {
      return false;
    }
  }

  if (!mir->compilingWasm() && !JitOptions.disableIteratorIndices) {
    if (!OptimizeIteratorIndices(mir, graph)) {
      return false;
    }
    gs.spewPass("Iterator Indices");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("Iterator Indices")) {
      return false;
    }
  }

  if (!JitOptions.disableRecoverIns &&
      mir->optimizationInfo().scalarReplacementEnabled()) {
    JitSpewCont(JitSpew_Escape, "\n");
    if (!ScalarReplacement(mir, graph)) {
      return false;
    }
    gs.spewPass("Scalar Replacement");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("Scalar Replacement")) {
      return false;
    }
  }

  if (!mir->compilingWasm()) {
    if (!ApplyTypeInformation(mir, graph)) {
      return false;
    }
    gs.spewPass("Apply types");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Apply types")) {
      return false;
    }
  }

  if (mir->optimizationInfo().amaEnabled()) {
    AlignmentMaskAnalysis ama(graph);
    if (!ama.analyze()) {
      return false;
    }
    gs.spewPass("Alignment Mask Analysis");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Alignment Mask Analysis")) {
      return false;
    }
  }

  ValueNumberer gvn(mir, graph);

  // Alias analysis is required for LICM and GVN so that we don't move
  // loads across stores. We also use alias information when removing
  // redundant shapeguards.
  if (mir->optimizationInfo().licmEnabled() ||
      mir->optimizationInfo().gvnEnabled() ||
      mir->optimizationInfo().eliminateRedundantShapeGuardsEnabled()) {
    {
      AliasAnalysis analysis(mir, graph);
      JitSpewCont(JitSpew_Alias, "\n");
      if (!analysis.analyze()) {
        return false;
      }

      gs.spewPass("Alias analysis");
      AssertExtendedGraphCoherency(graph);

      if (mir->shouldCancel("Alias analysis")) {
        return false;
      }
    }

    if (!mir->compilingWasm()) {
      // Eliminating dead resume point operands requires basic block
      // instructions to be numbered. Reuse the numbering computed during
      // alias analysis.
      if (!EliminateDeadResumePointOperands(mir, graph)) {
        return false;
      }

      gs.spewPass("Eliminate dead resume point operands");
      AssertExtendedGraphCoherency(graph);

      if (mir->shouldCancel("Eliminate dead resume point operands")) {
        return false;
      }
    }
  }

  if (mir->optimizationInfo().gvnEnabled()) {
    JitSpewCont(JitSpew_GVN, "\n");
    if (!gvn.run(ValueNumberer::UpdateAliasAnalysis)) {
      return false;
    }
    gs.spewPass("GVN");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("GVN")) {
      return false;
    }
  }

  if (mir->branchHintingEnabled()) {
    JitSpewCont(JitSpew_BranchHint, "\n");
    if (!BranchHinting(mir, graph)) {
      return false;
    }
    gs.spewPass("BranchHinting");
    AssertBasicGraphCoherency(graph);

    if (mir->shouldCancel("BranchHinting")) {
      return false;
    }
  }

  // LICM can hoist instructions from conditional branches and
  // trigger bailouts. Disable it if bailing out of a hoisted
  // instruction has previously invalidated this script.
  if (mir->licmEnabled()) {
    JitSpewCont(JitSpew_LICM, "\n");
    if (!LICM(mir, graph)) {
      return false;
    }
    gs.spewPass("LICM");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("LICM")) {
      return false;
    }
  }

  RangeAnalysis r(mir, graph);
  if (mir->optimizationInfo().rangeAnalysisEnabled()) {
    JitSpewCont(JitSpew_Range, "\n");
    if (!r.addBetaNodes()) {
      return false;
    }
    gs.spewPass("Beta");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("RA Beta")) {
      return false;
    }

    if (!r.analyze() || !r.addRangeAssertions()) {
      return false;
    }
    gs.spewPass("Range Analysis");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Range Analysis")) {
      return false;
    }

    if (!r.removeBetaNodes()) {
      return false;
    }
    gs.spewPass("De-Beta");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("RA De-Beta")) {
      return false;
    }

    if (mir->optimizationInfo().gvnEnabled()) {
      bool shouldRunUCE = false;
      if (!r.prepareForUCE(&shouldRunUCE)) {
        return false;
      }
      gs.spewPass("RA check UCE");
      AssertExtendedGraphCoherency(graph);

      if (mir->shouldCancel("RA check UCE")) {
        return false;
      }

      if (shouldRunUCE) {
        if (!gvn.run(ValueNumberer::DontUpdateAliasAnalysis)) {
          return false;
        }
        gs.spewPass("UCE After RA");
        AssertExtendedGraphCoherency(graph);

        if (mir->shouldCancel("UCE After RA")) {
          return false;
        }
      }
    }

    if (mir->optimizationInfo().autoTruncateEnabled()) {
      if (!r.truncate()) {
        return false;
      }
      gs.spewPass("Truncate Doubles");
      AssertExtendedGraphCoherency(graph);

      if (mir->shouldCancel("Truncate Doubles")) {
        return false;
      }
    }
  }

  if (!JitOptions.disableRecoverIns) {
    JitSpewCont(JitSpew_Sink, "\n");
    if (!Sink(mir, graph)) {
      return false;
    }
    gs.spewPass("Sink");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Sink")) {
      return false;
    }
  }

  if (!JitOptions.disableRecoverIns &&
      mir->optimizationInfo().rangeAnalysisEnabled()) {
    JitSpewCont(JitSpew_Range, "\n");
    if (!r.removeUnnecessaryBitops()) {
      return false;
    }
    gs.spewPass("Remove Unnecessary Bitops");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Remove Unnecessary Bitops")) {
      return false;
    }
  }

  {
    JitSpewCont(JitSpew_FLAC, "\n");
    if (!FoldLinearArithConstants(mir, graph)) {
      return false;
    }
    gs.spewPass("Fold Linear Arithmetic Constants");
    AssertBasicGraphCoherency(graph);

    if (mir->shouldCancel("Fold Linear Arithmetic Constants")) {
      return false;
    }
  }

  if (mir->optimizationInfo().eaaEnabled()) {
    EffectiveAddressAnalysis eaa(mir, graph);
    JitSpewCont(JitSpew_EAA, "\n");
    if (!eaa.analyze()) {
      return false;
    }
    gs.spewPass("Effective Address Analysis");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Effective Address Analysis")) {
      return false;
    }
  }

  // BCE marks bounds checks as dead, so do BCE before DCE.
  if (mir->compilingWasm()) {
    JitSpewCont(JitSpew_WasmBCE, "\n");
    if (!EliminateBoundsChecks(mir, graph)) {
      return false;
    }
    gs.spewPass("Redundant Bounds Check Elimination");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("BCE")) {
      return false;
    }
  }

  {
    if (!EliminateDeadCode(mir, graph)) {
      return false;
    }
    gs.spewPass("DCE");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("DCE")) {
      return false;
    }
  }

  if (!JitOptions.disableMarkLoadsUsedAsPropertyKeys && !mir->compilingWasm()) {
    JitSpewCont(JitSpew_MarkLoadsUsedAsPropertyKeys, "\n");
    if (!MarkLoadsUsedAsPropertyKeys(graph)) {
      return false;
    }
    if (mir->shouldCancel("MarkLoadsUsedAsPropertyKeys")) {
      return false;
    }
  }

  if (mir->optimizationInfo().instructionReorderingEnabled() &&
      !mir->outerInfo().hadReorderingBailout()) {
    if (!ReorderInstructions(graph)) {
      return false;
    }
    gs.spewPass("Reordering");

    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Reordering")) {
      return false;
    }
  }

  // Make loops contiguous. We do this after GVN/UCE and range analysis,
  // which can remove CFG edges, exposing more blocks that can be moved.
  {
    if (!MakeLoopsContiguous(graph)) {
      return false;
    }
    gs.spewPass("Make loops contiguous");
    AssertExtendedGraphCoherency(graph);

    if (mir->shouldCancel("Make loops contiguous")) {
      return false;
    }
  }
  AssertExtendedGraphCoherency(graph, /* underValueNumberer = */ false,
                               /* force = */ true);

  // Remove unreachable blocks created by MBasicBlock::NewFakeLoopPredecessor
  // to ensure every loop header has two predecessors. (This only happens due
  // to OSR.)  After this point, it is no longer possible to build the
  // dominator tree.
  if (!mir->compilingWasm() && graph.osrBlock()) {
    graph.removeFakeLoopPredecessors();
    gs.spewPass("Remove fake loop predecessors");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("Remove fake loop predecessors")) {
      return false;
    }
  }

  // Passes after this point must not move instructions; these analyses
  // depend on knowing the final order in which instructions will execute.

  if (mir->optimizationInfo().edgeCaseAnalysisEnabled()) {
    EdgeCaseAnalysis edgeCaseAnalysis(mir, graph);
    if (!edgeCaseAnalysis.analyzeLate()) {
      return false;
    }
    gs.spewPass("Edge Case Analysis (Late)");
    AssertGraphCoherency(graph);

    if (mir->shouldCancel("Edge Case Analysis (Late)")) {
      return false;
    }
  }

  if (mir->optimizationInfo().eliminateRedundantChecksEnabled()) {
    // Note: check elimination has to run after all other passes that move
    // instructions. Since check uses are replaced with the actual index,
    // code motion after this pass could incorrectly move a load or store
    // before its bounds check.
    if (!EliminateRedundantChecks(graph)) {
      return false;
    }
    gs.spewPass("Bounds Check Elimination");
    AssertGraphCoherency(graph);
  }

  if (mir->optimizationInfo().eliminateRedundantShapeGuardsEnabled()) {
    if (!EliminateRedundantShapeGuards(graph)) {
      return false;
    }
    gs.spewPass("Shape Guard Elimination");
    AssertGraphCoherency(graph);
  }

  // Run the GC Barrier Elimination pass after instruction reordering, to
  // ensure we don't move instructions that can trigger GC between stores we
  // optimize here.
  if (mir->optimizationInfo().eliminateRedundantGCBarriersEnabled()) {
    if (!EliminateRedundantGCBarriers(graph)) {
      return false;
    }
    gs.spewPass("GC Barrier Elimination");
    AssertGraphCoherency(graph);
  }

  if (!mir->compilingWasm() && !mir->outerInfo().hadUnboxFoldingBailout()) {
    if (!FoldLoadsWithUnbox(mir, graph)) {
      return false;
    }
    gs.spewPass("FoldLoadsWithUnbox");
    AssertGraphCoherency(graph);
  }

  if (!mir->compilingWasm()) {
    if (!AddKeepAliveInstructions(graph)) {
      return false;
    }
    gs.spewPass("Add KeepAlive Instructions");
    AssertGraphCoherency(graph);
  }

  AssertGraphCoherency(graph, /* force = */ true);

  if (JitSpewEnabled(JitSpew_MIRExpressions)) {
    JitSpewCont(JitSpew_MIRExpressions, "\n");
    DumpMIRExpressions(JitSpewPrinter(), graph, mir->outerInfo(),
                       "BeforeLIR (== result of OptimizeMIR)");
  }

  return true;
}

LIRGraph* GenerateLIR(MIRGenerator* mir) {
  MIRGraph& graph = mir->graph();
  GraphSpewer& gs = mir->graphSpewer();

  LIRGraph* lir = mir->alloc().lifoAlloc()->new_<LIRGraph>(&graph);
  if (!lir || !lir->init()) {
    return nullptr;
  }

  LIRGenerator lirgen(mir, graph, *lir);
  {
    if (!lirgen.generate()) {
      return nullptr;
    }
    gs.spewPass("Generate LIR");

    if (mir->shouldCancel("Generate LIR")) {
      return nullptr;
    }
  }

#ifdef DEBUG
  AllocationIntegrityState integrity(*lir);
#endif

  {
    IonRegisterAllocator allocator =
        mir->optimizationInfo().registerAllocator();

    switch (allocator) {
      case RegisterAllocator_Backtracking:
      case RegisterAllocator_Testbed: {
#ifdef DEBUG
        if (JitOptions.fullDebugChecks) {
          if (!integrity.record()) {
            return nullptr;
          }
        }
#endif

        BacktrackingAllocator regalloc(mir, &lirgen, *lir,
                                       allocator == RegisterAllocator_Testbed);
        if (!regalloc.go()) {
          return nullptr;
        }

#ifdef DEBUG
        if (JitOptions.fullDebugChecks) {
          if (!integrity.check()) {
            return nullptr;
          }
        }
#endif

        gs.spewPass("Allocate Registers [Backtracking]");
        break;
      }

      default:
        MOZ_CRASH("Bad regalloc");
    }

    if (mir->shouldCancel("Allocate Registers")) {
      return nullptr;
    }
  }

  return lir;
}

CodeGenerator* GenerateCode(MIRGenerator* mir, LIRGraph* lir) {
  auto codegen = MakeUnique<CodeGenerator>(mir, lir);
  if (!codegen) {
    return nullptr;
  }

  if (!codegen->generate()) {
    return nullptr;
  }

  return codegen.release();
}

CodeGenerator* CompileBackEnd(MIRGenerator* mir, WarpSnapshot* snapshot) {
  // Everything in CompileBackEnd can potentially run on a helper thread.
  AutoEnterIonBackend enter;
  AutoSpewEndFunction spewEndFunction(mir);

  {
    WarpCompilation comp(mir->alloc());
    WarpBuilder builder(*snapshot, *mir, &comp);
    if (!builder.build()) {
      return nullptr;
    }
  }

  if (!OptimizeMIR(mir)) {
    return nullptr;
  }

  LIRGraph* lir = GenerateLIR(mir);
  if (!lir) {
    return nullptr;
  }

  return GenerateCode(mir, lir);
}

static AbortReasonOr<WarpSnapshot*> CreateWarpSnapshot(JSContext* cx,
                                                       MIRGenerator* mirGen,
                                                       HandleScript script) {
  // Suppress GC during compilation.
  gc::AutoSuppressGC suppressGC(cx);

  SpewBeginFunction(mirGen, script);

  WarpOracle oracle(cx, *mirGen, script);

  AbortReasonOr<WarpSnapshot*> result = oracle.createSnapshot();

  MOZ_ASSERT_IF(result.isErr(), result.unwrapErr() == AbortReason::Alloc ||
                                    result.unwrapErr() == AbortReason::Error ||
                                    result.unwrapErr() == AbortReason::Disable);
  MOZ_ASSERT_IF(!result.isErr(), result.unwrap());

  return result;
}

static AbortReason IonCompile(JSContext* cx, HandleScript script,
                              jsbytecode* osrPc) {
  cx->check(script);

  auto alloc =
      cx->make_unique<LifoAlloc>(TempAllocator::PreferredLifoChunkSize);
  if (!alloc) {
    return AbortReason::Error;
  }

  if (!cx->zone()->ensureJitZoneExists(cx)) {
    return AbortReason::Error;
  }

  if (!cx->zone()->jitZone()->ensureIonStubsExist(cx)) {
    return AbortReason::Error;
  }

  TempAllocator* temp = alloc->new_<TempAllocator>(alloc.get());
  if (!temp) {
    return AbortReason::Alloc;
  }

  MIRGraph* graph = alloc->new_<MIRGraph>(temp);
  if (!graph) {
    return AbortReason::Alloc;
  }

  InlineScriptTree* inlineScriptTree =
      InlineScriptTree::New(temp, nullptr, nullptr, script);
  if (!inlineScriptTree) {
    return AbortReason::Alloc;
  }

  CompileInfo* info = alloc->new_<CompileInfo>(
      CompileRuntime::get(cx->runtime()), script, script->function(), osrPc,
      script->needsArgsObj(), inlineScriptTree);
  if (!info) {
    return AbortReason::Alloc;
  }

  const OptimizationInfo* optimizationInfo =
      IonOptimizations.get(OptimizationLevel::Normal);
  const JitCompileOptions options(cx);

  MIRGenerator* mirGen =
      alloc->new_<MIRGenerator>(CompileRealm::get(cx->realm()), options, temp,
                                graph, info, optimizationInfo);
  if (!mirGen) {
    return AbortReason::Alloc;
  }

  MOZ_ASSERT(!script->baselineScript()->hasPendingIonCompileTask());
  MOZ_ASSERT(!script->hasIonScript());
  MOZ_ASSERT(script->canIonCompile());

  if (osrPc) {
    script->jitScript()->setHadIonOSR();
  }

  AbortReasonOr<WarpSnapshot*> result = CreateWarpSnapshot(cx, mirGen, script);
  if (result.isErr()) {
    return result.unwrapErr();
  }
  WarpSnapshot* snapshot = result.unwrap();

  // If possible, compile the script off thread.
  if (options.offThreadCompilationAvailable()) {
    JitSpew(JitSpew_IonSyncLogs,
            "Can't log script %s:%u:%u"
            ". (Compiled on background thread.)",
            script->filename(), script->lineno(),
            script->column().oneOriginValue());

    IonCompileTask* task = alloc->new_<IonCompileTask>(cx, *mirGen, snapshot);
    if (!task) {
      return AbortReason::Alloc;
    }

    AutoLockHelperThreadState lock;
    if (!StartOffThreadIonCompile(task, lock)) {
      JitSpew(JitSpew_IonAbort, "Unable to start off-thread ion compilation.");
      mirGen->graphSpewer().endFunction();
      return AbortReason::Alloc;
    }

    script->jitScript()->setIsIonCompilingOffThread(script);

    // The allocator and associated data will be destroyed after being
    // processed in the finishedOffThreadCompilations list.
    (void)alloc.release();

    return AbortReason::NoAbort;
  }

  bool succeeded = false;
  {
    gc::AutoSuppressGC suppressGC(cx);
    JitContext jctx(cx);
    UniquePtr<CodeGenerator> codegen(CompileBackEnd(mirGen, snapshot));
    if (!codegen) {
      JitSpew(JitSpew_IonAbort, "Failed during back-end compilation.");
      if (cx->isExceptionPending()) {
        return AbortReason::Error;
      }
      return AbortReason::Disable;
    }

    succeeded = LinkCodeGen(cx, codegen.get(), script, snapshot);
  }

  if (succeeded) {
    return AbortReason::NoAbort;
  }
  if (cx->isExceptionPending()) {
    return AbortReason::Error;
  }
  return AbortReason::Disable;
}

static bool CheckFrame(JSContext* cx, BaselineFrame* frame) {
  MOZ_ASSERT(!frame->isDebuggerEvalFrame());
  MOZ_ASSERT(!frame->isEvalFrame());

  // This check is to not overrun the stack.
  if (frame->isFunctionFrame()) {
    if (TooManyActualArguments(frame->numActualArgs())) {
      JitSpew(JitSpew_IonAbort, "too many actual arguments");
      return false;
    }

    if (TooManyFormalArguments(frame->numFormalArgs())) {
      JitSpew(JitSpew_IonAbort, "too many arguments");
      return false;
    }
  }

  return true;
}

static bool CanIonCompileOrInlineScript(JSScript* script, const char** reason) {
  if (script->isForEval()) {
    // Eval frames are not yet supported. Supporting this will require new
    // logic in pushBailoutFrame to deal with linking prev.
    // Additionally, JSOp::GlobalOrEvalDeclInstantiation support will require
    // baking in isEvalFrame().
    *reason = "eval script";
    return false;
  }

  if (script->isAsync()) {
    if (script->isModule()) {
      *reason = "async module";
      return false;
    }
  }

  if (script->hasNonSyntacticScope() && !script->function()) {
    // Support functions with a non-syntactic global scope but not other
    // scripts. For global scripts, WarpBuilder currently uses the global
    // object as scope chain, this is not valid when the script has a
    // non-syntactic global scope.
    *reason = "has non-syntactic global scope";
    return false;
  }

  return true;
}  // namespace jit

static bool ScriptIsTooLarge(JSContext* cx, JSScript* script) {
  if (!JitOptions.limitScriptSize) {
    return false;
  }

  size_t numLocalsAndArgs = NumLocalsAndArgs(script);

  bool canCompileOffThread = OffThreadCompilationAvailable(cx);
  size_t maxScriptSize = canCompileOffThread
                             ? JitOptions.ionMaxScriptSize
                             : JitOptions.ionMaxScriptSizeMainThread;
  size_t maxLocalsAndArgs = canCompileOffThread
                                ? JitOptions.ionMaxLocalsAndArgs
                                : JitOptions.ionMaxLocalsAndArgsMainThread;

  if (script->length() > maxScriptSize || numLocalsAndArgs > maxLocalsAndArgs) {
    JitSpew(JitSpew_IonAbort,
            "Script too large (%zu bytes) (%zu locals/args) @ %s:%u:%u",
            script->length(), numLocalsAndArgs, script->filename(),
            script->lineno(), script->column().oneOriginValue());
    return true;
  }

  return false;
}

bool CanIonCompileScript(JSContext* cx, JSScript* script) {
  if (!script->canIonCompile()) {
    return false;
  }

  const char* reason = nullptr;
  if (!CanIonCompileOrInlineScript(script, &reason)) {
    JitSpew(JitSpew_IonAbort, "%s", reason);
    return false;
  }

  if (ScriptIsTooLarge(cx, script)) {
    return false;
  }

  return true;
}

static MethodStatus Compile(JSContext* cx, HandleScript script,
                            BaselineFrame* osrFrame, jsbytecode* osrPc) {
  MOZ_ASSERT(jit::IsIonEnabled(cx));
  MOZ_ASSERT(jit::IsBaselineJitEnabled(cx));

  MOZ_ASSERT(script->hasBaselineScript());
  MOZ_ASSERT(!script->baselineScript()->hasPendingIonCompileTask());
  MOZ_ASSERT(!script->hasIonScript());

  AutoGeckoProfilerEntry pseudoFrame(
      cx, "Ion script compilation",
      JS::ProfilingCategoryPair::JS_IonCompilation);

  if (script->isDebuggee() || (osrFrame && osrFrame->isDebuggee())) {
    JitSpew(JitSpew_IonAbort, "debugging");
    return Method_Skipped;
  }

  if (!CanIonCompileScript(cx, script)) {
    JitSpew(JitSpew_IonAbort, "Aborted compilation of %s:%u:%u",
            script->filename(), script->lineno(),
            script->column().oneOriginValue());
    return Method_CantCompile;
  }

  OptimizationLevel optimizationLevel =
      IonOptimizations.levelForScript(cx, script, osrPc);
  if (optimizationLevel == OptimizationLevel::DontCompile) {
    return Method_Skipped;
  }

  MOZ_ASSERT(optimizationLevel == OptimizationLevel::Normal);

  if (!CanLikelyAllocateMoreExecutableMemory()) {
    script->resetWarmUpCounterToDelayIonCompilation();
    return Method_Skipped;
  }

  MOZ_ASSERT(!script->hasIonScript());

  AbortReason reason = IonCompile(cx, script, osrPc);
  if (reason == AbortReason::Error) {
    MOZ_ASSERT(cx->isExceptionPending());
    return Method_Error;
  }

  if (reason == AbortReason::Disable) {
    return Method_CantCompile;
  }

  if (reason == AbortReason::Alloc) {
    ReportOutOfMemory(cx);
    return Method_Error;
  }

  // Compilation succeeded or we invalidated right away or an inlining/alloc
  // abort
  if (script->hasIonScript()) {
    return Method_Compiled;
  }
  return Method_Skipped;
}

}  // namespace jit
}  // namespace js

bool jit::OffThreadCompilationAvailable(JSContext* cx) {
  // Even if off thread compilation is enabled, compilation must still occur
  // on the main thread in some cases.
  //
  // Require cpuCount > 1 so that Ion compilation jobs and active-thread
  // execution are not competing for the same resources.
  return cx->runtime()->canUseOffthreadIonCompilation() &&
         GetHelperThreadCPUCount() > 1 && CanUseExtraThreads();
}

MethodStatus jit::CanEnterIon(JSContext* cx, RunState& state) {
  MOZ_ASSERT(jit::IsIonEnabled(cx));

  HandleScript script = state.script();
  MOZ_ASSERT(!script->hasIonScript());

  // Skip if the script has been disabled.
  if (!script->canIonCompile()) {
    return Method_Skipped;
  }

  // Skip if the script is being compiled off thread.
  if (script->isIonCompilingOffThread()) {
    return Method_Skipped;
  }

  if (state.isInvoke()) {
    InvokeState& invoke = *state.asInvoke();

    if (TooManyActualArguments(invoke.args().length())) {
      JitSpew(JitSpew_IonAbort, "too many actual args");
      ForbidCompilation(cx, script);
      return Method_CantCompile;
    }

    if (TooManyFormalArguments(
            invoke.args().callee().as<JSFunction>().nargs())) {
      JitSpew(JitSpew_IonAbort, "too many args");
      ForbidCompilation(cx, script);
      return Method_CantCompile;
    }
  }

  // If --ion-eager is used, compile with Baseline first, so that we
  // can directly enter IonMonkey.
  if (JitOptions.eagerIonCompilation() && !script->hasBaselineScript()) {
    MethodStatus status =
        CanEnterBaselineMethod<BaselineTier::Compiler>(cx, state);
    if (status != Method_Compiled) {
      return status;
    }
    // Bytecode analysis may forbid compilation for a script.
    if (!script->canIonCompile()) {
      return Method_CantCompile;
    }
  }

  if (!script->hasBaselineScript()) {
    return Method_Skipped;
  }

  MOZ_ASSERT(!script->isIonCompilingOffThread());
  MOZ_ASSERT(script->canIonCompile());

  // Attempt compilation. Returns Method_Compiled if already compiled.
  MethodStatus status = Compile(cx, script, /* osrFrame = */ nullptr,
                                /* osrPc = */ nullptr);
  if (status != Method_Compiled) {
    if (status == Method_CantCompile) {
      ForbidCompilation(cx, script);
    }
    return status;
  }

  if (state.script()->baselineScript()->hasPendingIonCompileTask()) {
    LinkIonScript(cx, state.script());
    if (!state.script()->hasIonScript()) {
      return jit::Method_Skipped;
    }
  }

  return Method_Compiled;
}

static MethodStatus BaselineCanEnterAtEntry(JSContext* cx, HandleScript script,
                                            BaselineFrame* frame) {
  MOZ_ASSERT(jit::IsIonEnabled(cx));
  MOZ_ASSERT(script->canIonCompile());
  MOZ_ASSERT(!script->isIonCompilingOffThread());
  MOZ_ASSERT(!script->hasIonScript());
  MOZ_ASSERT(frame->isFunctionFrame());

  // Mark as forbidden if frame can't be handled.
  if (!CheckFrame(cx, frame)) {
    ForbidCompilation(cx, script);
    return Method_CantCompile;
  }

  if (script->baselineScript()->hasPendingIonCompileTask()) {
    LinkIonScript(cx, script);
    if (script->hasIonScript()) {
      return Method_Compiled;
    }
  }

  // Attempt compilation. Returns Method_Compiled if already compiled.
  MethodStatus status = Compile(cx, script, frame, nullptr);
  if (status != Method_Compiled) {
    if (status == Method_CantCompile) {
      ForbidCompilation(cx, script);
    }
    return status;
  }

  return Method_Compiled;
}

// Decide if a transition from baseline execution to Ion code should occur.
// May compile or recompile the target JSScript.
static MethodStatus BaselineCanEnterAtBranch(JSContext* cx, HandleScript script,
                                             BaselineFrame* osrFrame,
                                             jsbytecode* pc) {
  MOZ_ASSERT(jit::IsIonEnabled(cx));
  MOZ_ASSERT((JSOp)*pc == JSOp::LoopHead);

  // Skip if the script has been disabled.
  if (!script->canIonCompile()) {
    return Method_Skipped;
  }

  // Skip if the script is being compiled off thread.
  if (script->isIonCompilingOffThread()) {
    return Method_Skipped;
  }

  // Optionally ignore on user request.
  if (!JitOptions.osr) {
    return Method_Skipped;
  }

  // Mark as forbidden if frame can't be handled.
  if (!CheckFrame(cx, osrFrame)) {
    ForbidCompilation(cx, script);
    return Method_CantCompile;
  }

  // Check if the jitcode still needs to get linked and do this
  // to have a valid IonScript.
  if (script->baselineScript()->hasPendingIonCompileTask()) {
    LinkIonScript(cx, script);
  }

  // By default a recompilation doesn't happen on osr mismatch.
  // Decide if we want to force a recompilation if this happens too much.
  if (script->hasIonScript()) {
    if (pc == script->ionScript()->osrPc()) {
      return Method_Compiled;
    }

    uint32_t count = script->ionScript()->incrOsrPcMismatchCounter();
    if (count <= JitOptions.osrPcMismatchesBeforeRecompile &&
        !JitOptions.eagerIonCompilation()) {
      return Method_Skipped;
    }

    JitSpew(JitSpew_IonScripts, "Forcing OSR Mismatch Compilation");
    Invalidate(cx, script);
  }

  // Attempt compilation.
  // - Returns Method_Compiled if the right ionscript is present
  //   (Meaning it was present or a sequantial compile finished)
  // - Returns Method_Skipped if pc doesn't match
  //   (This means a background thread compilation with that pc could have
  //   started or not.)
  MethodStatus status = Compile(cx, script, osrFrame, pc);
  if (status != Method_Compiled) {
    if (status == Method_CantCompile) {
      ForbidCompilation(cx, script);
    }
    return status;
  }

  // Return the compilation was skipped when the osr pc wasn't adjusted.
  // This can happen when there was still an IonScript available and a
  // background compilation started, but hasn't finished yet.
  // Or when we didn't force a recompile.
  if (script->hasIonScript() && pc != script->ionScript()->osrPc()) {
    return Method_Skipped;
  }

  return Method_Compiled;
}

static bool IonCompileScriptForBaseline(JSContext* cx, BaselineFrame* frame,
                                        jsbytecode* pc) {
  MOZ_ASSERT(IsIonEnabled(cx));

  RootedScript script(cx, frame->script());
  bool isLoopHead = JSOp(*pc) == JSOp::LoopHead;

  // The Baseline JIT code checks for Ion disabled or compiling off-thread.
  MOZ_ASSERT(script->canIonCompile());
  MOZ_ASSERT(!script->isIonCompilingOffThread());

  // If Ion script exists, but PC is not at a loop entry, then Ion will be
  // entered for this script at an appropriate LOOPENTRY or the next time this
  // function is called.
  if (script->hasIonScript() && !isLoopHead) {
    JitSpew(JitSpew_BaselineOSR, "IonScript exists, but not at loop entry!");
    // TODO: ASSERT that a ion-script-already-exists checker stub doesn't exist.
    // TODO: Clear all optimized stubs.
    // TODO: Add a ion-script-already-exists checker stub.
    return true;
  }

  // Ensure that Ion-compiled code is available.
  JitSpew(JitSpew_BaselineOSR,
          "WarmUpCounter for %s:%u:%u reached %d at pc %p, trying to switch to "
          "Ion!",
          script->filename(), script->lineno(),
          script->column().oneOriginValue(), (int)script->getWarmUpCount(),
          (void*)pc);

  MethodStatus stat;
  if (isLoopHead) {
    JitSpew(JitSpew_BaselineOSR, "  Compile at loop head!");
    stat = BaselineCanEnterAtBranch(cx, script, frame, pc);
  } else if (frame->isFunctionFrame()) {
    JitSpew(JitSpew_BaselineOSR,
            "  Compile function from top for later entry!");
    stat = BaselineCanEnterAtEntry(cx, script, frame);
  } else {
    return true;
  }

  if (stat == Method_Error) {
    JitSpew(JitSpew_BaselineOSR, "  Compile with Ion errored!");
    return false;
  }

  if (stat == Method_CantCompile) {
    MOZ_ASSERT(!script->canIonCompile());
    JitSpew(JitSpew_BaselineOSR, "  Can't compile with Ion!");
  } else if (stat == Method_Skipped) {
    JitSpew(JitSpew_BaselineOSR, "  Skipped compile with Ion!");
  } else if (stat == Method_Compiled) {
    JitSpew(JitSpew_BaselineOSR, "  Compiled with Ion!");
  } else {
    MOZ_CRASH("Invalid MethodStatus!");
  }

  return true;
}

bool jit::IonCompileScriptForBaselineAtEntry(JSContext* cx,
                                             BaselineFrame* frame) {
  JSScript* script = frame->script();
  return IonCompileScriptForBaseline(cx, frame, script->code());
}

/* clang-format off */
// The following data is kept in a temporary heap-allocated buffer, stored in
// JitRuntime (high memory addresses at top, low at bottom):
//
//     +----->+=================================+  --      <---- High Address
//     |      |                                 |   |
//     |      |     ...BaselineFrame...         |   |-- Copy of BaselineFrame + stack values
//     |      |                                 |   |
//     |      +---------------------------------+   |
//     |      |                                 |   |
//     |      |     ...Locals/Stack...          |   |
//     |      |                                 |   |
//     |      +=================================+  --
//     |      |     Padding(Maybe Empty)        |
//     |      +=================================+  --
//     +------|-- baselineFrame                 |   |-- IonOsrTempData
//            |   jitcode                       |   |
//            +=================================+  --      <---- Low Address
//
// A pointer to the IonOsrTempData is returned.
/* clang-format on */

static IonOsrTempData* PrepareOsrTempData(JSContext* cx, BaselineFrame* frame,
                                          uint32_t frameSize, void* jitcode) {
  uint32_t numValueSlots = frame->numValueSlots(frameSize);

  // Calculate the amount of space to allocate:
  //      BaselineFrame space:
  //          (sizeof(Value) * numValueSlots)
  //        + sizeof(BaselineFrame)
  //
  //      IonOsrTempData space:
  //          sizeof(IonOsrTempData)

  size_t frameSpace = sizeof(BaselineFrame) + sizeof(Value) * numValueSlots;
  size_t ionOsrTempDataSpace = sizeof(IonOsrTempData);

  size_t totalSpace = AlignBytes(frameSpace, sizeof(Value)) +
                      AlignBytes(ionOsrTempDataSpace, sizeof(Value));

  JitRuntime* jrt = cx->runtime()->jitRuntime();
  uint8_t* buf = jrt->allocateIonOsrTempData(totalSpace);
  if (!buf) {
    ReportOutOfMemory(cx);
    return nullptr;
  }

  IonOsrTempData* info = new (buf) IonOsrTempData();
  info->jitcode = jitcode;

  // Copy the BaselineFrame + local/stack Values to the buffer. Arguments and
  // |this| are not copied but left on the stack: the Baseline and Ion frame
  // share the same frame prefix and Ion won't clobber these values. Note
  // that info->baselineFrame will point to the *end* of the frame data, like
  // the frame pointer register in baseline frames.
  uint8_t* frameStart =
      (uint8_t*)info + AlignBytes(ionOsrTempDataSpace, sizeof(Value));
  info->baselineFrame = frameStart + frameSpace;

  memcpy(frameStart, (uint8_t*)frame - numValueSlots * sizeof(Value),
         frameSpace);

  JitSpew(JitSpew_BaselineOSR, "Allocated IonOsrTempData at %p", info);
  JitSpew(JitSpew_BaselineOSR, "Jitcode is %p", info->jitcode);

  // All done.
  return info;
}

bool jit::IonCompileScriptForBaselineOSR(JSContext* cx, BaselineFrame* frame,
                                         uint32_t frameSize, jsbytecode* pc,
                                         IonOsrTempData** infoPtr) {
  MOZ_ASSERT(infoPtr);
  *infoPtr = nullptr;

  MOZ_ASSERT(frame->debugFrameSize() == frameSize);
  MOZ_ASSERT(JSOp(*pc) == JSOp::LoopHead);

  if (!IonCompileScriptForBaseline(cx, frame, pc)) {
    return false;
  }

  RootedScript script(cx, frame->script());
  if (!script->hasIonScript() || script->ionScript()->osrPc() != pc ||
      frame->isDebuggee()) {
    return true;
  }

  IonScript* ion = script->ionScript();
  MOZ_ASSERT(cx->runtime()->geckoProfiler().enabled() ==
             ion->hasProfilingInstrumentation());
  MOZ_ASSERT(ion->osrPc() == pc);

  ion->resetOsrPcMismatchCounter();

  JitSpew(JitSpew_BaselineOSR, "  OSR possible!");
  void* jitcode = ion->method()->raw() + ion->osrEntryOffset();

  // Prepare the temporary heap copy of the fake InterpreterFrame and actual
  // args list.
  JitSpew(JitSpew_BaselineOSR, "Got jitcode.  Preparing for OSR into ion.");
  IonOsrTempData* info = PrepareOsrTempData(cx, frame, frameSize, jitcode);
  if (!info) {
    return false;
  }

  *infoPtr = info;
  return true;
}

static void InvalidateActivation(JS::GCContext* gcx,
                                 const JitActivationIterator& activations,
                                 bool invalidateAll) {
  JitSpew(JitSpew_IonInvalidate, "BEGIN invalidating activation");

#ifdef CHECK_OSIPOINT_REGISTERS
  if (JitOptions.checkOsiPointRegisters) {
    activations->asJit()->setCheckRegs(false);
  }
#endif

  size_t frameno = 1;

  for (OnlyJSJitFrameIter iter(activations); !iter.done(); ++iter, ++frameno) {
    const JSJitFrameIter& frame = iter.frame();
    MOZ_ASSERT_IF(frameno == 1, frame.isExitFrame() ||
                                    frame.type() == FrameType::Bailout ||
                                    frame.type() == FrameType::JSJitToWasm);

#ifdef JS_JITSPEW
    switch (frame.type()) {
      case FrameType::Exit:
        JitSpew(JitSpew_IonInvalidate, "#%zu exit frame @ %p", frameno,
                frame.fp());
        break;
      case FrameType::JSJitToWasm:
        JitSpew(JitSpew_IonInvalidate, "#%zu wasm exit frame @ %p", frameno,
                frame.fp());
        break;
      case FrameType::BaselineJS:
      case FrameType::IonJS:
      case FrameType::Bailout: {
        MOZ_ASSERT(frame.isScripted());
        const char* type = "Unknown";
        if (frame.isIonJS()) {
          type = "Optimized";
        } else if (frame.isBaselineJS()) {
          type = "Baseline";
        } else if (frame.isBailoutJS()) {
          type = "Bailing";
        }
        JSScript* script = frame.maybeForwardedScript();
        JitSpew(JitSpew_IonInvalidate,
                "#%zu %s JS frame @ %p, %s:%u:%u (fun: %p, script: %p, pc %p)",
                frameno, type, frame.fp(), script->maybeForwardedFilename(),
                script->lineno(), script->column().oneOriginValue(),
                frame.maybeCallee(), script, frame.resumePCinCurrentFrame());
        break;
      }
      case FrameType::BaselineStub:
        JitSpew(JitSpew_IonInvalidate, "#%zu baseline stub frame @ %p", frameno,
                frame.fp());
        break;
      case FrameType::BaselineInterpreterEntry:
        JitSpew(JitSpew_IonInvalidate,
                "#%zu baseline interpreter entry frame @ %p", frameno,
                frame.fp());
        break;
      case FrameType::Rectifier:
        JitSpew(JitSpew_IonInvalidate, "#%zu rectifier frame @ %p", frameno,
                frame.fp());
        break;
      case FrameType::TrampolineNative:
        JitSpew(JitSpew_IonInvalidate, "#%zu TrampolineNative frame @ %p",
                frameno, frame.fp());
        break;
      case FrameType::IonICCall:
        JitSpew(JitSpew_IonInvalidate, "#%zu ion IC call frame @ %p", frameno,
                frame.fp());
        break;
      case FrameType::CppToJSJit:
        JitSpew(JitSpew_IonInvalidate, "#%zu entry frame @ %p", frameno,
                frame.fp());
        break;
      case FrameType::WasmToJSJit:
        JitSpew(JitSpew_IonInvalidate, "#%zu wasm frames @ %p", frameno,
                frame.fp());
        break;
    }
#endif  // JS_JITSPEW

    if (!frame.isIonScripted()) {
      continue;
    }

    // See if the frame has already been invalidated.
    if (frame.checkInvalidation()) {
      continue;
    }

    JSScript* script = frame.maybeForwardedScript();
    if (!script->hasIonScript()) {
      continue;
    }

    if (!invalidateAll && !script->ionScript()->invalidated()) {
      continue;
    }

    IonScript* ionScript = script->ionScript();

    // Purge ICs before we mark this script as invalidated. This will
    // prevent lastJump_ from appearing to be a bogus pointer, just
    // in case anyone tries to read it.
    ionScript->purgeICs(script->zone());

    // This frame needs to be invalidated. We do the following:
    //
    // 1. Increment the reference counter to keep the ionScript alive
    //    for the invalidation bailout or for the exception handler.
    // 2. Determine safepoint that corresponds to the current call.
    // 3. From safepoint, get distance to the OSI-patchable offset.
    // 4. From the IonScript, determine the distance between the
    //    call-patchable offset and the invalidation epilogue.
    // 5. Patch the OSI point with a call-relative to the
    //    invalidation epilogue.
    //
    // The code generator ensures that there's enough space for us
    // to patch in a call-relative operation at each invalidation
    // point.
    //
    // Note: you can't simplify this mechanism to "just patch the
    // instruction immediately after the call" because things may
    // need to move into a well-defined register state (using move
    // instructions after the call) in to capture an appropriate
    // snapshot after the call occurs.

    ionScript->incrementInvalidationCount();

    JitCode* ionCode = ionScript->method();

    // We're about to remove edges from the JSScript to GC things embedded in
    // the JitCode. Perform a barrier to let the GC know about those edges.
    PreWriteBarrier(script->zone(), ionCode, [](JSTracer* trc, JitCode* code) {
      code->traceChildren(trc);
    });

    ionCode->setInvalidated();

    // Don't adjust OSI points in a bailout path.
    if (frame.isBailoutJS()) {
      continue;
    }

    // Write the delta (from the return address offset to the
    // IonScript pointer embedded into the invalidation epilogue)
    // where the safepointed call instruction used to be. We rely on
    // the call sequence causing the safepoint being >= the size of
    // a uint32, which is checked during safepoint index
    // construction.
    AutoWritableJitCode awjc(ionCode);
    const SafepointIndex* si =
        ionScript->getSafepointIndex(frame.resumePCinCurrentFrame());
    CodeLocationLabel dataLabelToMunge(frame.resumePCinCurrentFrame());
    ptrdiff_t delta = ionScript->invalidateEpilogueDataOffset() -
                      (frame.resumePCinCurrentFrame() - ionCode->raw());
    Assembler::PatchWrite_Imm32(dataLabelToMunge, Imm32(delta));

    CodeLocationLabel osiPatchPoint =
        SafepointReader::InvalidationPatchPoint(ionScript, si);
    CodeLocationLabel invalidateEpilogue(
        ionCode, CodeOffset(ionScript->invalidateEpilogueOffset()));

    JitSpew(
        JitSpew_IonInvalidate,
        "   ! Invalidate ionScript %p (inv count %zu) -> patching osipoint %p",
        ionScript, ionScript->invalidationCount(), (void*)osiPatchPoint.raw());
    Assembler::PatchWrite_NearCall(osiPatchPoint, invalidateEpilogue);
  }

  JitSpew(JitSpew_IonInvalidate, "END invalidating activation");
}

void jit::InvalidateAll(JS::GCContext* gcx, Zone* zone) {
  // The caller should previously have cancelled off thread compilation.
  MOZ_ASSERT(!HasOffThreadIonCompile(zone));
  if (zone->isAtomsZone()) {
    return;
  }
  JSContext* cx = TlsContext.get();
  for (JitActivationIterator iter(cx); !iter.done(); ++iter) {
    if (iter->compartment()->zone() == zone) {
      JitSpew(JitSpew_IonInvalidate, "Invalidating all frames for GC");
      InvalidateActivation(gcx, iter, true);
    }
  }
}

static void ClearIonScriptAfterInvalidation(JSContext* cx, JSScript* script,
                                            IonScript* ionScript,
                                            bool resetUses) {
  // Null out the JitScript's IonScript pointer. The caller is responsible for
  // destroying the IonScript using the invalidation count mechanism.
  DebugOnly<IonScript*> clearedIonScript =
      script->jitScript()->clearIonScript(cx->gcContext(), script);
  MOZ_ASSERT(clearedIonScript == ionScript);

  // Wait for the scripts to get warm again before doing another
  // compile, unless we are recompiling *because* a script got hot
  // (resetUses is false).
  if (resetUses) {
    script->resetWarmUpCounterToDelayIonCompilation();
  }
}

void jit::Invalidate(JSContext* cx, const RecompileInfoVector& invalid,
                     bool resetUses, bool cancelOffThread) {
  JitSpew(JitSpew_IonInvalidate, "Start invalidation.");

  // Add an invalidation reference to all invalidated IonScripts to indicate
  // to the traversal which frames have been invalidated.
  size_t numInvalidations = 0;
  for (const RecompileInfo& info : invalid) {
    if (cancelOffThread) {
      CancelOffThreadIonCompile(info.script());
    }

    IonScript* ionScript = info.maybeIonScriptToInvalidate();
    if (!ionScript) {
      continue;
    }

    JitSpew(JitSpew_IonInvalidate, " Invalidate %s:%u:%u, IonScript %p",
            info.script()->filename(), info.script()->lineno(),
            info.script()->column().oneOriginValue(), ionScript);

    // Keep the ion script alive during the invalidation and flag this
    // ionScript as being invalidated.  This increment is removed by the
    // loop after the calls to InvalidateActivation.
    ionScript->incrementInvalidationCount();
    numInvalidations++;
  }

  if (!numInvalidations) {
    JitSpew(JitSpew_IonInvalidate, " No IonScript invalidation.");
    return;
  }

  JS::GCContext* gcx = cx->gcContext();
  for (JitActivationIterator iter(cx); !iter.done(); ++iter) {
    InvalidateActivation(gcx, iter, false);
  }

  // Drop the references added above. If a script was never active, its
  // IonScript will be immediately destroyed. Otherwise, it will be held live
  // until its last invalidated frame is destroyed.
  for (const RecompileInfo& info : invalid) {
    IonScript* ionScript = info.maybeIonScriptToInvalidate();
    if (!ionScript) {
      continue;
    }

    if (ionScript->invalidationCount() == 1) {
      // decrementInvalidationCount will destroy the IonScript so null out
      // jitScript->ionScript_ now. We don't want to do this unconditionally
      // because maybeIonScriptToInvalidate depends on script->ionScript() (we
      // would leak the IonScript if |invalid| contains duplicates).
      ClearIonScriptAfterInvalidation(cx, info.script(), ionScript, resetUses);
    }

    ionScript->decrementInvalidationCount(gcx);
    numInvalidations--;
  }

  // Make sure we didn't leak references by invalidating the same IonScript
  // multiple times in the above loop.
  MOZ_ASSERT(!numInvalidations);

  // Finally, null out jitScript->ionScript_ for IonScripts that are still on
  // the stack.
  for (const RecompileInfo& info : invalid) {
    if (IonScript* ionScript = info.maybeIonScriptToInvalidate()) {
      ClearIonScriptAfterInvalidation(cx, info.script(), ionScript, resetUses);
    }
  }
}

void jit::IonScript::invalidate(JSContext* cx, JSScript* script, bool resetUses,
                                const char* reason) {
  // Note: we could short circuit here if we already invalidated this
  // IonScript, but jit::Invalidate also cancels off-thread compilations of
  // |script|.
  MOZ_RELEASE_ASSERT(invalidated() || script->ionScript() == this);

  JitSpew(JitSpew_IonInvalidate, " Invalidate IonScript %p: %s", this, reason);

  // RecompileInfoVector has inline space for at least one element.
  RecompileInfoVector list;
  MOZ_RELEASE_ASSERT(list.reserve(1));
  list.infallibleEmplaceBack(script, compilationId());

  Invalidate(cx, list, resetUses, true);
}

void jit::Invalidate(JSContext* cx, JSScript* script, bool resetUses,
                     bool cancelOffThread) {
  MOZ_ASSERT(script->hasIonScript());

  if (cx->runtime()->geckoProfiler().enabled()) {
    // Register invalidation with profiler.
    // Format of event payload string:
    //      "<filename>:<lineno>"

    // Get the script filename, if any, and its length.
    const char* filename = script->filename();
    if (filename == nullptr) {
      filename = "<unknown>";
    }

    // Construct the descriptive string.
    UniqueChars buf = JS_smprintf("%s:%u:%u", filename, script->lineno(),
                                  script->column().oneOriginValue());

    // Ignore the event on allocation failure.
    if (buf) {
      cx->runtime()->geckoProfiler().markEvent("Invalidate", buf.get());
    }
  }

  // RecompileInfoVector has inline space for at least one element.
  RecompileInfoVector scripts;
  MOZ_ASSERT(script->hasIonScript());
  MOZ_RELEASE_ASSERT(scripts.reserve(1));
  scripts.infallibleEmplaceBack(script, script->ionScript()->compilationId());

  Invalidate(cx, scripts, resetUses, cancelOffThread);
}

void jit::FinishInvalidation(JS::GCContext* gcx, JSScript* script) {
  if (!script->hasIonScript()) {
    return;
  }

  // In all cases, null out jitScript->ionScript_ to avoid re-entry.
  IonScript* ion = script->jitScript()->clearIonScript(gcx, script);

  // If this script has Ion code on the stack, invalidated() will return
  // true. In this case we have to wait until destroying it.
  if (!ion->invalidated()) {
    jit::IonScript::Destroy(gcx, ion);
  }
}

void jit::ForbidCompilation(JSContext* cx, JSScript* script) {
  JitSpew(JitSpew_IonAbort, "Disabling Ion compilation of script %s:%u:%u",
          script->filename(), script->lineno(),
          script->column().oneOriginValue());

  CancelOffThreadIonCompile(script);

  if (script->hasIonScript()) {
    Invalidate(cx, script, false);
  }

  script->disableIon();
}

size_t jit::SizeOfIonData(JSScript* script,
                          mozilla::MallocSizeOf mallocSizeOf) {
  size_t result = 0;

  if (script->hasIonScript()) {
    result += script->ionScript()->sizeOfIncludingThis(mallocSizeOf);
  }

  return result;
}

// If you change these, please also change the comment in TempAllocator.
/* static */ const size_t TempAllocator::BallastSize = 16 * 1024;
/* static */ const size_t TempAllocator::PreferredLifoChunkSize = 32 * 1024;