aboutsummaryrefslogtreecommitdiff
path: root/gcc/ifcvt.c
blob: 24542f008485e6c28e068030fa301f2ce040efc1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
/* If-conversion support.
   Copyright (C) 2000-2016 Free Software Foundation, Inc.

   This file is part of GCC.

   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

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

   You should have received a copy of the GNU General Public License
   along with GCC; see the file COPYING3.  If not see
   <http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "backend.h"
#include "target.h"
#include "rtl.h"
#include "tree.h"
#include "cfghooks.h"
#include "df.h"
#include "tm_p.h"
#include "expmed.h"
#include "optabs.h"
#include "regs.h"
#include "emit-rtl.h"
#include "recog.h"

#include "cfgrtl.h"
#include "cfganal.h"
#include "cfgcleanup.h"
#include "expr.h"
#include "output.h"
#include "cfgloop.h"
#include "tree-pass.h"
#include "dbgcnt.h"
#include "shrink-wrap.h"
#include "rtl-iter.h"
#include "ifcvt.h"
#include "params.h"

#ifndef MAX_CONDITIONAL_EXECUTE
#define MAX_CONDITIONAL_EXECUTE \
  (BRANCH_COST (optimize_function_for_speed_p (cfun), false) \
   + 1)
#endif

#define IFCVT_MULTIPLE_DUMPS 1

#define NULL_BLOCK	((basic_block) NULL)

/* True if after combine pass.  */
static bool ifcvt_after_combine;

/* True if the target has the cbranchcc4 optab.  */
static bool have_cbranchcc4;

/* # of IF-THEN or IF-THEN-ELSE blocks we looked at  */
static int num_possible_if_blocks;

/* # of IF-THEN or IF-THEN-ELSE blocks were converted to conditional
   execution.  */
static int num_updated_if_blocks;

/* # of changes made.  */
static int num_true_changes;

/* Whether conditional execution changes were made.  */
static int cond_exec_changed_p;

/* Forward references.  */
static int count_bb_insns (const_basic_block);
static bool cheap_bb_rtx_cost_p (const_basic_block, int, int);
static rtx_insn *first_active_insn (basic_block);
static rtx_insn *last_active_insn (basic_block, int);
static rtx_insn *find_active_insn_before (basic_block, rtx_insn *);
static rtx_insn *find_active_insn_after (basic_block, rtx_insn *);
static basic_block block_fallthru (basic_block);
static int cond_exec_process_insns (ce_if_block *, rtx_insn *, rtx, rtx, int,
				    int);
static rtx cond_exec_get_condition (rtx_insn *);
static rtx noce_get_condition (rtx_insn *, rtx_insn **, bool);
static int noce_operand_ok (const_rtx);
static void merge_if_block (ce_if_block *);
static int find_cond_trap (basic_block, edge, edge);
static basic_block find_if_header (basic_block, int);
static int block_jumps_and_fallthru_p (basic_block, basic_block);
static int noce_find_if_block (basic_block, edge, edge, int);
static int cond_exec_find_if_block (ce_if_block *);
static int find_if_case_1 (basic_block, edge, edge);
static int find_if_case_2 (basic_block, edge, edge);
static int dead_or_predicable (basic_block, basic_block, basic_block,
			       edge, int);
static void noce_emit_move_insn (rtx, rtx);
static rtx_insn *block_has_only_trap (basic_block);

/* Count the number of non-jump active insns in BB.  */

static int
count_bb_insns (const_basic_block bb)
{
  int count = 0;
  rtx_insn *insn = BB_HEAD (bb);

  while (1)
    {
      if (active_insn_p (insn) && !JUMP_P (insn))
	count++;

      if (insn == BB_END (bb))
	break;
      insn = NEXT_INSN (insn);
    }

  return count;
}

/* Determine whether the total insn_rtx_cost on non-jump insns in
   basic block BB is less than MAX_COST.  This function returns
   false if the cost of any instruction could not be estimated. 

   The cost of the non-jump insns in BB is scaled by REG_BR_PROB_BASE
   as those insns are being speculated.  MAX_COST is scaled with SCALE
   plus a small fudge factor.  */

static bool
cheap_bb_rtx_cost_p (const_basic_block bb, int scale, int max_cost)
{
  int count = 0;
  rtx_insn *insn = BB_HEAD (bb);
  bool speed = optimize_bb_for_speed_p (bb);

  /* Set scale to REG_BR_PROB_BASE to void the identical scaling
     applied to insn_rtx_cost when optimizing for size.  Only do
     this after combine because if-conversion might interfere with
     passes before combine.

     Use optimize_function_for_speed_p instead of the pre-defined
     variable speed to make sure it is set to same value for all
     basic blocks in one if-conversion transformation.  */
  if (!optimize_function_for_speed_p (cfun) && ifcvt_after_combine)
    scale = REG_BR_PROB_BASE;
  /* Our branch probability/scaling factors are just estimates and don't
     account for cases where we can get speculation for free and other
     secondary benefits.  So we fudge the scale factor to make speculating
     appear a little more profitable when optimizing for performance.  */
  else
    scale += REG_BR_PROB_BASE / 8;


  max_cost *= scale;

  while (1)
    {
      if (NONJUMP_INSN_P (insn))
	{
	  int cost = insn_rtx_cost (PATTERN (insn), speed) * REG_BR_PROB_BASE;
	  if (cost == 0)
	    return false;

	  /* If this instruction is the load or set of a "stack" register,
	     such as a floating point register on x87, then the cost of
	     speculatively executing this insn may need to include
	     the additional cost of popping its result off of the
	     register stack.  Unfortunately, correctly recognizing and
	     accounting for this additional overhead is tricky, so for
	     now we simply prohibit such speculative execution.  */
#ifdef STACK_REGS
	  {
	    rtx set = single_set (insn);
	    if (set && STACK_REG_P (SET_DEST (set)))
	      return false;
	  }
#endif

	  count += cost;
	  if (count >= max_cost)
	    return false;
	}
      else if (CALL_P (insn))
	return false;

      if (insn == BB_END (bb))
	break;
      insn = NEXT_INSN (insn);
    }

  return true;
}

/* Return the first non-jump active insn in the basic block.  */

static rtx_insn *
first_active_insn (basic_block bb)
{
  rtx_insn *insn = BB_HEAD (bb);

  if (LABEL_P (insn))
    {
      if (insn == BB_END (bb))
	return NULL;
      insn = NEXT_INSN (insn);
    }

  while (NOTE_P (insn) || DEBUG_INSN_P (insn))
    {
      if (insn == BB_END (bb))
	return NULL;
      insn = NEXT_INSN (insn);
    }

  if (JUMP_P (insn))
    return NULL;

  return insn;
}

/* Return the last non-jump active (non-jump) insn in the basic block.  */

static rtx_insn *
last_active_insn (basic_block bb, int skip_use_p)
{
  rtx_insn *insn = BB_END (bb);
  rtx_insn *head = BB_HEAD (bb);

  while (NOTE_P (insn)
	 || JUMP_P (insn)
	 || DEBUG_INSN_P (insn)
	 || (skip_use_p
	     && NONJUMP_INSN_P (insn)
	     && GET_CODE (PATTERN (insn)) == USE))
    {
      if (insn == head)
	return NULL;
      insn = PREV_INSN (insn);
    }

  if (LABEL_P (insn))
    return NULL;

  return insn;
}

/* Return the active insn before INSN inside basic block CURR_BB. */

static rtx_insn *
find_active_insn_before (basic_block curr_bb, rtx_insn *insn)
{
  if (!insn || insn == BB_HEAD (curr_bb))
    return NULL;

  while ((insn = PREV_INSN (insn)) != NULL_RTX)
    {
      if (NONJUMP_INSN_P (insn) || JUMP_P (insn) || CALL_P (insn))
        break;

      /* No other active insn all the way to the start of the basic block. */
      if (insn == BB_HEAD (curr_bb))
        return NULL;
    }

  return insn;
}

/* Return the active insn after INSN inside basic block CURR_BB. */

static rtx_insn *
find_active_insn_after (basic_block curr_bb, rtx_insn *insn)
{
  if (!insn || insn == BB_END (curr_bb))
    return NULL;

  while ((insn = NEXT_INSN (insn)) != NULL_RTX)
    {
      if (NONJUMP_INSN_P (insn) || JUMP_P (insn) || CALL_P (insn))
        break;

      /* No other active insn all the way to the end of the basic block. */
      if (insn == BB_END (curr_bb))
        return NULL;
    }

  return insn;
}

/* Return the basic block reached by falling though the basic block BB.  */

static basic_block
block_fallthru (basic_block bb)
{
  edge e = find_fallthru_edge (bb->succs);

  return (e) ? e->dest : NULL_BLOCK;
}

/* Return true if RTXs A and B can be safely interchanged.  */

static bool
rtx_interchangeable_p (const_rtx a, const_rtx b)
{
  if (!rtx_equal_p (a, b))
    return false;

  if (GET_CODE (a) != MEM)
    return true;

  /* A dead type-unsafe memory reference is legal, but a live type-unsafe memory
     reference is not.  Interchanging a dead type-unsafe memory reference with
     a live type-safe one creates a live type-unsafe memory reference, in other
     words, it makes the program illegal.
     We check here conservatively whether the two memory references have equal
     memory attributes.  */

  return mem_attrs_eq_p (get_mem_attrs (a), get_mem_attrs (b));
}


/* Go through a bunch of insns, converting them to conditional
   execution format if possible.  Return TRUE if all of the non-note
   insns were processed.  */

static int
cond_exec_process_insns (ce_if_block *ce_info ATTRIBUTE_UNUSED,
			 /* if block information */rtx_insn *start,
			 /* first insn to look at */rtx end,
			 /* last insn to look at */rtx test,
			 /* conditional execution test */int prob_val,
			 /* probability of branch taken. */int mod_ok)
{
  int must_be_last = FALSE;
  rtx_insn *insn;
  rtx xtest;
  rtx pattern;

  if (!start || !end)
    return FALSE;

  for (insn = start; ; insn = NEXT_INSN (insn))
    {
      /* dwarf2out can't cope with conditional prologues.  */
      if (NOTE_P (insn) && NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
	return FALSE;

      if (NOTE_P (insn) || DEBUG_INSN_P (insn))
	goto insn_done;

      gcc_assert (NONJUMP_INSN_P (insn) || CALL_P (insn));

      /* dwarf2out can't cope with conditional unwind info.  */
      if (RTX_FRAME_RELATED_P (insn))
	return FALSE;

      /* Remove USE insns that get in the way.  */
      if (reload_completed && GET_CODE (PATTERN (insn)) == USE)
	{
	  /* ??? Ug.  Actually unlinking the thing is problematic,
	     given what we'd have to coordinate with our callers.  */
	  SET_INSN_DELETED (insn);
	  goto insn_done;
	}

      /* Last insn wasn't last?  */
      if (must_be_last)
	return FALSE;

      if (modified_in_p (test, insn))
	{
	  if (!mod_ok)
	    return FALSE;
	  must_be_last = TRUE;
	}

      /* Now build the conditional form of the instruction.  */
      pattern = PATTERN (insn);
      xtest = copy_rtx (test);

      /* If this is already a COND_EXEC, rewrite the test to be an AND of the
         two conditions.  */
      if (GET_CODE (pattern) == COND_EXEC)
	{
	  if (GET_MODE (xtest) != GET_MODE (COND_EXEC_TEST (pattern)))
	    return FALSE;

	  xtest = gen_rtx_AND (GET_MODE (xtest), xtest,
			       COND_EXEC_TEST (pattern));
	  pattern = COND_EXEC_CODE (pattern);
	}

      pattern = gen_rtx_COND_EXEC (VOIDmode, xtest, pattern);

      /* If the machine needs to modify the insn being conditionally executed,
         say for example to force a constant integer operand into a temp
         register, do so here.  */
#ifdef IFCVT_MODIFY_INSN
      IFCVT_MODIFY_INSN (ce_info, pattern, insn);
      if (! pattern)
	return FALSE;
#endif

      validate_change (insn, &PATTERN (insn), pattern, 1);

      if (CALL_P (insn) && prob_val >= 0)
	validate_change (insn, &REG_NOTES (insn),
			 gen_rtx_INT_LIST ((machine_mode) REG_BR_PROB,
					   prob_val, REG_NOTES (insn)), 1);

    insn_done:
      if (insn == end)
	break;
    }

  return TRUE;
}

/* Return the condition for a jump.  Do not do any special processing.  */

static rtx
cond_exec_get_condition (rtx_insn *jump)
{
  rtx test_if, cond;

  if (any_condjump_p (jump))
    test_if = SET_SRC (pc_set (jump));
  else
    return NULL_RTX;
  cond = XEXP (test_if, 0);

  /* If this branches to JUMP_LABEL when the condition is false,
     reverse the condition.  */
  if (GET_CODE (XEXP (test_if, 2)) == LABEL_REF
      && LABEL_REF_LABEL (XEXP (test_if, 2)) == JUMP_LABEL (jump))
    {
      enum rtx_code rev = reversed_comparison_code (cond, jump);
      if (rev == UNKNOWN)
	return NULL_RTX;

      cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
			     XEXP (cond, 1));
    }

  return cond;
}

/* Given a simple IF-THEN or IF-THEN-ELSE block, attempt to convert it
   to conditional execution.  Return TRUE if we were successful at
   converting the block.  */

static int
cond_exec_process_if_block (ce_if_block * ce_info,
			    /* if block information */int do_multiple_p)
{
  basic_block test_bb = ce_info->test_bb;	/* last test block */
  basic_block then_bb = ce_info->then_bb;	/* THEN */
  basic_block else_bb = ce_info->else_bb;	/* ELSE or NULL */
  rtx test_expr;		/* expression in IF_THEN_ELSE that is tested */
  rtx_insn *then_start;		/* first insn in THEN block */
  rtx_insn *then_end;		/* last insn + 1 in THEN block */
  rtx_insn *else_start = NULL;	/* first insn in ELSE block or NULL */
  rtx_insn *else_end = NULL;	/* last insn + 1 in ELSE block */
  int max;			/* max # of insns to convert.  */
  int then_mod_ok;		/* whether conditional mods are ok in THEN */
  rtx true_expr;		/* test for else block insns */
  rtx false_expr;		/* test for then block insns */
  int true_prob_val;		/* probability of else block */
  int false_prob_val;		/* probability of then block */
  rtx_insn *then_last_head = NULL;	/* Last match at the head of THEN */
  rtx_insn *else_last_head = NULL;	/* Last match at the head of ELSE */
  rtx_insn *then_first_tail = NULL;	/* First match at the tail of THEN */
  rtx_insn *else_first_tail = NULL;	/* First match at the tail of ELSE */
  int then_n_insns, else_n_insns, n_insns;
  enum rtx_code false_code;
  rtx note;

  /* If test is comprised of && or || elements, and we've failed at handling
     all of them together, just use the last test if it is the special case of
     && elements without an ELSE block.  */
  if (!do_multiple_p && ce_info->num_multiple_test_blocks)
    {
      if (else_bb || ! ce_info->and_and_p)
	return FALSE;

      ce_info->test_bb = test_bb = ce_info->last_test_bb;
      ce_info->num_multiple_test_blocks = 0;
      ce_info->num_and_and_blocks = 0;
      ce_info->num_or_or_blocks = 0;
    }

  /* Find the conditional jump to the ELSE or JOIN part, and isolate
     the test.  */
  test_expr = cond_exec_get_condition (BB_END (test_bb));
  if (! test_expr)
    return FALSE;

  /* If the conditional jump is more than just a conditional jump,
     then we can not do conditional execution conversion on this block.  */
  if (! onlyjump_p (BB_END (test_bb)))
    return FALSE;

  /* Collect the bounds of where we're to search, skipping any labels, jumps
     and notes at the beginning and end of the block.  Then count the total
     number of insns and see if it is small enough to convert.  */
  then_start = first_active_insn (then_bb);
  then_end = last_active_insn (then_bb, TRUE);
  then_n_insns = ce_info->num_then_insns = count_bb_insns (then_bb);
  n_insns = then_n_insns;
  max = MAX_CONDITIONAL_EXECUTE;

  if (else_bb)
    {
      int n_matching;

      max *= 2;
      else_start = first_active_insn (else_bb);
      else_end = last_active_insn (else_bb, TRUE);
      else_n_insns = ce_info->num_else_insns = count_bb_insns (else_bb);
      n_insns += else_n_insns;

      /* Look for matching sequences at the head and tail of the two blocks,
	 and limit the range of insns to be converted if possible.  */
      n_matching = flow_find_cross_jump (then_bb, else_bb,
					 &then_first_tail, &else_first_tail,
					 NULL);
      if (then_first_tail == BB_HEAD (then_bb))
	then_start = then_end = NULL;
      if (else_first_tail == BB_HEAD (else_bb))
	else_start = else_end = NULL;

      if (n_matching > 0)
	{
	  if (then_end)
	    then_end = find_active_insn_before (then_bb, then_first_tail);
	  if (else_end)
	    else_end = find_active_insn_before (else_bb, else_first_tail);
	  n_insns -= 2 * n_matching;
	}

      if (then_start
	  && else_start
	  && then_n_insns > n_matching
	  && else_n_insns > n_matching)
	{
	  int longest_match = MIN (then_n_insns - n_matching,
				   else_n_insns - n_matching);
	  n_matching
	    = flow_find_head_matching_sequence (then_bb, else_bb,
						&then_last_head,
						&else_last_head,
						longest_match);

	  if (n_matching > 0)
	    {
	      rtx_insn *insn;

	      /* We won't pass the insns in the head sequence to
		 cond_exec_process_insns, so we need to test them here
		 to make sure that they don't clobber the condition.  */
	      for (insn = BB_HEAD (then_bb);
		   insn != NEXT_INSN (then_last_head);
		   insn = NEXT_INSN (insn))
		if (!LABEL_P (insn) && !NOTE_P (insn)
		    && !DEBUG_INSN_P (insn)
		    && modified_in_p (test_expr, insn))
		  return FALSE;
	    }

	  if (then_last_head == then_end)
	    then_start = then_end = NULL;
	  if (else_last_head == else_end)
	    else_start = else_end = NULL;

	  if (n_matching > 0)
	    {
	      if (then_start)
		then_start = find_active_insn_after (then_bb, then_last_head);
	      if (else_start)
		else_start = find_active_insn_after (else_bb, else_last_head);
	      n_insns -= 2 * n_matching;
	    }
	}
    }

  if (n_insns > max)
    return FALSE;

  /* Map test_expr/test_jump into the appropriate MD tests to use on
     the conditionally executed code.  */

  true_expr = test_expr;

  false_code = reversed_comparison_code (true_expr, BB_END (test_bb));
  if (false_code != UNKNOWN)
    false_expr = gen_rtx_fmt_ee (false_code, GET_MODE (true_expr),
				 XEXP (true_expr, 0), XEXP (true_expr, 1));
  else
    false_expr = NULL_RTX;

#ifdef IFCVT_MODIFY_TESTS
  /* If the machine description needs to modify the tests, such as setting a
     conditional execution register from a comparison, it can do so here.  */
  IFCVT_MODIFY_TESTS (ce_info, true_expr, false_expr);

  /* See if the conversion failed.  */
  if (!true_expr || !false_expr)
    goto fail;
#endif

  note = find_reg_note (BB_END (test_bb), REG_BR_PROB, NULL_RTX);
  if (note)
    {
      true_prob_val = XINT (note, 0);
      false_prob_val = REG_BR_PROB_BASE - true_prob_val;
    }
  else
    {
      true_prob_val = -1;
      false_prob_val = -1;
    }

  /* If we have && or || tests, do them here.  These tests are in the adjacent
     blocks after the first block containing the test.  */
  if (ce_info->num_multiple_test_blocks > 0)
    {
      basic_block bb = test_bb;
      basic_block last_test_bb = ce_info->last_test_bb;

      if (! false_expr)
	goto fail;

      do
	{
	  rtx_insn *start, *end;
	  rtx t, f;
	  enum rtx_code f_code;

	  bb = block_fallthru (bb);
	  start = first_active_insn (bb);
	  end = last_active_insn (bb, TRUE);
	  if (start
	      && ! cond_exec_process_insns (ce_info, start, end, false_expr,
					    false_prob_val, FALSE))
	    goto fail;

	  /* If the conditional jump is more than just a conditional jump, then
	     we can not do conditional execution conversion on this block.  */
	  if (! onlyjump_p (BB_END (bb)))
	    goto fail;

	  /* Find the conditional jump and isolate the test.  */
	  t = cond_exec_get_condition (BB_END (bb));
	  if (! t)
	    goto fail;

	  f_code = reversed_comparison_code (t, BB_END (bb));
	  if (f_code == UNKNOWN)
	    goto fail;

	  f = gen_rtx_fmt_ee (f_code, GET_MODE (t), XEXP (t, 0), XEXP (t, 1));
	  if (ce_info->and_and_p)
	    {
	      t = gen_rtx_AND (GET_MODE (t), true_expr, t);
	      f = gen_rtx_IOR (GET_MODE (t), false_expr, f);
	    }
	  else
	    {
	      t = gen_rtx_IOR (GET_MODE (t), true_expr, t);
	      f = gen_rtx_AND (GET_MODE (t), false_expr, f);
	    }

	  /* If the machine description needs to modify the tests, such as
	     setting a conditional execution register from a comparison, it can
	     do so here.  */
#ifdef IFCVT_MODIFY_MULTIPLE_TESTS
	  IFCVT_MODIFY_MULTIPLE_TESTS (ce_info, bb, t, f);

	  /* See if the conversion failed.  */
	  if (!t || !f)
	    goto fail;
#endif

	  true_expr = t;
	  false_expr = f;
	}
      while (bb != last_test_bb);
    }

  /* For IF-THEN-ELSE blocks, we don't allow modifications of the test
     on then THEN block.  */
  then_mod_ok = (else_bb == NULL_BLOCK);

  /* Go through the THEN and ELSE blocks converting the insns if possible
     to conditional execution.  */

  if (then_end
      && (! false_expr
	  || ! cond_exec_process_insns (ce_info, then_start, then_end,
					false_expr, false_prob_val,
					then_mod_ok)))
    goto fail;

  if (else_bb && else_end
      && ! cond_exec_process_insns (ce_info, else_start, else_end,
				    true_expr, true_prob_val, TRUE))
    goto fail;

  /* If we cannot apply the changes, fail.  Do not go through the normal fail
     processing, since apply_change_group will call cancel_changes.  */
  if (! apply_change_group ())
    {
#ifdef IFCVT_MODIFY_CANCEL
      /* Cancel any machine dependent changes.  */
      IFCVT_MODIFY_CANCEL (ce_info);
#endif
      return FALSE;
    }

#ifdef IFCVT_MODIFY_FINAL
  /* Do any machine dependent final modifications.  */
  IFCVT_MODIFY_FINAL (ce_info);
#endif

  /* Conversion succeeded.  */
  if (dump_file)
    fprintf (dump_file, "%d insn%s converted to conditional execution.\n",
	     n_insns, (n_insns == 1) ? " was" : "s were");

  /* Merge the blocks!  If we had matching sequences, make sure to delete one
     copy at the appropriate location first: delete the copy in the THEN branch
     for a tail sequence so that the remaining one is executed last for both
     branches, and delete the copy in the ELSE branch for a head sequence so
     that the remaining one is executed first for both branches.  */
  if (then_first_tail)
    {
      rtx_insn *from = then_first_tail;
      if (!INSN_P (from))
	from = find_active_insn_after (then_bb, from);
      delete_insn_chain (from, get_last_bb_insn (then_bb), false);
    }
  if (else_last_head)
    delete_insn_chain (first_active_insn (else_bb), else_last_head, false);

  merge_if_block (ce_info);
  cond_exec_changed_p = TRUE;
  return TRUE;

 fail:
#ifdef IFCVT_MODIFY_CANCEL
  /* Cancel any machine dependent changes.  */
  IFCVT_MODIFY_CANCEL (ce_info);
#endif

  cancel_changes (0);
  return FALSE;
}

/* Used by noce_process_if_block to communicate with its subroutines.

   The subroutines know that A and B may be evaluated freely.  They
   know that X is a register.  They should insert new instructions
   before cond_earliest.  */

struct noce_if_info
{
  /* The basic blocks that make up the IF-THEN-{ELSE-,}JOIN block.  */
  basic_block test_bb, then_bb, else_bb, join_bb;

  /* The jump that ends TEST_BB.  */
  rtx_insn *jump;

  /* The jump condition.  */
  rtx cond;

  /* New insns should be inserted before this one.  */
  rtx_insn *cond_earliest;

  /* Insns in the THEN and ELSE block.  There is always just this
     one insns in those blocks.  The insns are single_set insns.
     If there was no ELSE block, INSN_B is the last insn before
     COND_EARLIEST, or NULL_RTX.  In the former case, the insn
     operands are still valid, as if INSN_B was moved down below
     the jump.  */
  rtx_insn *insn_a, *insn_b;

  /* The SET_SRC of INSN_A and INSN_B.  */
  rtx a, b;

  /* The SET_DEST of INSN_A.  */
  rtx x;

  /* The original set destination that the THEN and ELSE basic blocks finally
     write their result to.  */
  rtx orig_x;
  /* True if this if block is not canonical.  In the canonical form of
     if blocks, the THEN_BB is the block reached via the fallthru edge
     from TEST_BB.  For the noce transformations, we allow the symmetric
     form as well.  */
  bool then_else_reversed;

  /* True if the contents of then_bb and else_bb are a
     simple single set instruction.  */
  bool then_simple;
  bool else_simple;

  /* True if we're optimisizing the control block for speed, false if
     we're optimizing for size.  */
  bool speed_p;

  /* The combined cost of COND, JUMP and the costs for THEN_BB and
     ELSE_BB.  */
  unsigned int original_cost;

  /* Maximum permissible cost for the unconditional sequence we should
     generate to replace this branch.  */
  unsigned int max_seq_cost;

  /* The name of the noce transform that succeeded in if-converting
     this structure.  Used for debugging.  */
  const char *transform_name;
};

static rtx noce_emit_store_flag (struct noce_if_info *, rtx, int, int);
static int noce_try_move (struct noce_if_info *);
static int noce_try_ifelse_collapse (struct noce_if_info *);
static int noce_try_store_flag (struct noce_if_info *);
static int noce_try_addcc (struct noce_if_info *);
static int noce_try_store_flag_constants (struct noce_if_info *);
static int noce_try_store_flag_mask (struct noce_if_info *);
static rtx noce_emit_cmove (struct noce_if_info *, rtx, enum rtx_code, rtx,
			    rtx, rtx, rtx);
static int noce_try_cmove (struct noce_if_info *);
static int noce_try_cmove_arith (struct noce_if_info *);
static rtx noce_get_alt_condition (struct noce_if_info *, rtx, rtx_insn **);
static int noce_try_minmax (struct noce_if_info *);
static int noce_try_abs (struct noce_if_info *);
static int noce_try_sign_mask (struct noce_if_info *);

/* Return TRUE if SEQ is a good candidate as a replacement for the
   if-convertible sequence described in IF_INFO.  */

inline static bool
noce_conversion_profitable_p (rtx_insn *seq, struct noce_if_info *if_info)
{
  bool speed_p = if_info->speed_p;

  /* Cost up the new sequence.  */
  unsigned int cost = seq_cost (seq, speed_p);

  /* When compiling for size, we can make a reasonably accurately guess
     at the size growth.  */
  if (!speed_p)
    return cost <= if_info->original_cost;
  else
    return cost <= if_info->max_seq_cost;
}

/* Helper function for noce_try_store_flag*.  */

static rtx
noce_emit_store_flag (struct noce_if_info *if_info, rtx x, int reversep,
		      int normalize)
{
  rtx cond = if_info->cond;
  int cond_complex;
  enum rtx_code code;

  cond_complex = (! general_operand (XEXP (cond, 0), VOIDmode)
		  || ! general_operand (XEXP (cond, 1), VOIDmode));

  /* If earliest == jump, or when the condition is complex, try to
     build the store_flag insn directly.  */

  if (cond_complex)
    {
      rtx set = pc_set (if_info->jump);
      cond = XEXP (SET_SRC (set), 0);
      if (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
	  && LABEL_REF_LABEL (XEXP (SET_SRC (set), 2)) == JUMP_LABEL (if_info->jump))
	reversep = !reversep;
      if (if_info->then_else_reversed)
	reversep = !reversep;
    }

  if (reversep)
    code = reversed_comparison_code (cond, if_info->jump);
  else
    code = GET_CODE (cond);

  if ((if_info->cond_earliest == if_info->jump || cond_complex)
      && (normalize == 0 || STORE_FLAG_VALUE == normalize))
    {
      rtx src = gen_rtx_fmt_ee (code, GET_MODE (x), XEXP (cond, 0),
			    XEXP (cond, 1));
      rtx set = gen_rtx_SET (x, src);

      start_sequence ();
      rtx_insn *insn = emit_insn (set);

      if (recog_memoized (insn) >= 0)
	{
	  rtx_insn *seq = get_insns ();
	  end_sequence ();
	  emit_insn (seq);

	  if_info->cond_earliest = if_info->jump;

	  return x;
	}

      end_sequence ();
    }

  /* Don't even try if the comparison operands or the mode of X are weird.  */
  if (cond_complex || !SCALAR_INT_MODE_P (GET_MODE (x)))
    return NULL_RTX;

  return emit_store_flag (x, code, XEXP (cond, 0),
			  XEXP (cond, 1), VOIDmode,
			  (code == LTU || code == LEU
			   || code == GEU || code == GTU), normalize);
}

/* Emit instruction to move an rtx, possibly into STRICT_LOW_PART.
   X is the destination/target and Y is the value to copy.  */

static void
noce_emit_move_insn (rtx x, rtx y)
{
  machine_mode outmode;
  rtx outer, inner;
  int bitpos;

  if (GET_CODE (x) != STRICT_LOW_PART)
    {
      rtx_insn *seq, *insn;
      rtx target;
      optab ot;

      start_sequence ();
      /* Check that the SET_SRC is reasonable before calling emit_move_insn,
	 otherwise construct a suitable SET pattern ourselves.  */
      insn = (OBJECT_P (y) || CONSTANT_P (y) || GET_CODE (y) == SUBREG)
	     ? emit_move_insn (x, y)
	     : emit_insn (gen_rtx_SET (x, y));
      seq = get_insns ();
      end_sequence ();

      if (recog_memoized (insn) <= 0)
	{
	  if (GET_CODE (x) == ZERO_EXTRACT)
	    {
	      rtx op = XEXP (x, 0);
	      unsigned HOST_WIDE_INT size = INTVAL (XEXP (x, 1));
	      unsigned HOST_WIDE_INT start = INTVAL (XEXP (x, 2));

	      /* store_bit_field expects START to be relative to
		 BYTES_BIG_ENDIAN and adjusts this value for machines with
		 BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN.  In order to be able to
		 invoke store_bit_field again it is necessary to have the START
		 value from the first call.  */
	      if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
		{
		  if (MEM_P (op))
		    start = BITS_PER_UNIT - start - size;
		  else
		    {
		      gcc_assert (REG_P (op));
		      start = BITS_PER_WORD - start - size;
		    }
		}

	      gcc_assert (start < (MEM_P (op) ? BITS_PER_UNIT : BITS_PER_WORD));
	      store_bit_field (op, size, start, 0, 0, GET_MODE (x), y, false);
	      return;
	    }

	  switch (GET_RTX_CLASS (GET_CODE (y)))
	    {
	    case RTX_UNARY:
	      ot = code_to_optab (GET_CODE (y));
	      if (ot)
		{
		  start_sequence ();
		  target = expand_unop (GET_MODE (y), ot, XEXP (y, 0), x, 0);
		  if (target != NULL_RTX)
		    {
		      if (target != x)
			emit_move_insn (x, target);
		      seq = get_insns ();
		    }
		  end_sequence ();
		}
	      break;

	    case RTX_BIN_ARITH:
	    case RTX_COMM_ARITH:
	      ot = code_to_optab (GET_CODE (y));
	      if (ot)
		{
		  start_sequence ();
		  target = expand_binop (GET_MODE (y), ot,
					 XEXP (y, 0), XEXP (y, 1),
					 x, 0, OPTAB_DIRECT);
		  if (target != NULL_RTX)
		    {
		      if (target != x)
			  emit_move_insn (x, target);
		      seq = get_insns ();
		    }
		  end_sequence ();
		}
	      break;

	    default:
	      break;
	    }
	}

      emit_insn (seq);
      return;
    }

  outer = XEXP (x, 0);
  inner = XEXP (outer, 0);
  outmode = GET_MODE (outer);
  bitpos = SUBREG_BYTE (outer) * BITS_PER_UNIT;
  store_bit_field (inner, GET_MODE_BITSIZE (outmode), bitpos,
		   0, 0, outmode, y, false);
}

/* Return the CC reg if it is used in COND.  */

static rtx
cc_in_cond (rtx cond)
{
  if (have_cbranchcc4 && cond
      && GET_MODE_CLASS (GET_MODE (XEXP (cond, 0))) == MODE_CC)
    return XEXP (cond, 0);

  return NULL_RTX;
}

/* Return sequence of instructions generated by if conversion.  This
   function calls end_sequence() to end the current stream, ensures
   that the instructions are unshared, recognizable non-jump insns.
   On failure, this function returns a NULL_RTX.  */

static rtx_insn *
end_ifcvt_sequence (struct noce_if_info *if_info)
{
  rtx_insn *insn;
  rtx_insn *seq = get_insns ();
  rtx cc = cc_in_cond (if_info->cond);

  set_used_flags (if_info->x);
  set_used_flags (if_info->cond);
  set_used_flags (if_info->a);
  set_used_flags (if_info->b);

  for (insn = seq; insn; insn = NEXT_INSN (insn))
    set_used_flags (insn);

  unshare_all_rtl_in_chain (seq);
  end_sequence ();

  /* Make sure that all of the instructions emitted are recognizable,
     and that we haven't introduced a new jump instruction.
     As an exercise for the reader, build a general mechanism that
     allows proper placement of required clobbers.  */
  for (insn = seq; insn; insn = NEXT_INSN (insn))
    if (JUMP_P (insn)
	|| recog_memoized (insn) == -1
	   /* Make sure new generated code does not clobber CC.  */
	|| (cc && set_of (cc, insn)))
      return NULL;

  return seq;
}

/* Return true iff the then and else basic block (if it exists)
   consist of a single simple set instruction.  */

static bool
noce_simple_bbs (struct noce_if_info *if_info)
{
  if (!if_info->then_simple)
    return false;

  if (if_info->else_bb)
    return if_info->else_simple;

  return true;
}

/* Convert "if (a != b) x = a; else x = b" into "x = a" and
   "if (a == b) x = a; else x = b" into "x = b".  */

static int
noce_try_move (struct noce_if_info *if_info)
{
  rtx cond = if_info->cond;
  enum rtx_code code = GET_CODE (cond);
  rtx y;
  rtx_insn *seq;

  if (code != NE && code != EQ)
    return FALSE;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  /* This optimization isn't valid if either A or B could be a NaN
     or a signed zero.  */
  if (HONOR_NANS (if_info->x)
      || HONOR_SIGNED_ZEROS (if_info->x))
    return FALSE;

  /* Check whether the operands of the comparison are A and in
     either order.  */
  if ((rtx_equal_p (if_info->a, XEXP (cond, 0))
       && rtx_equal_p (if_info->b, XEXP (cond, 1)))
      || (rtx_equal_p (if_info->a, XEXP (cond, 1))
	  && rtx_equal_p (if_info->b, XEXP (cond, 0))))
    {
      if (!rtx_interchangeable_p (if_info->a, if_info->b))
	return FALSE;

      y = (code == EQ) ? if_info->a : if_info->b;

      /* Avoid generating the move if the source is the destination.  */
      if (! rtx_equal_p (if_info->x, y))
	{
	  start_sequence ();
	  noce_emit_move_insn (if_info->x, y);
	  seq = end_ifcvt_sequence (if_info);
	  if (!seq)
	    return FALSE;

	  emit_insn_before_setloc (seq, if_info->jump,
				   INSN_LOCATION (if_info->insn_a));
	}
      if_info->transform_name = "noce_try_move";
      return TRUE;
    }
  return FALSE;
}

/* Try forming an IF_THEN_ELSE (cond, b, a) and collapsing that
   through simplify_rtx.  Sometimes that can eliminate the IF_THEN_ELSE.
   If that is the case, emit the result into x.  */

static int
noce_try_ifelse_collapse (struct noce_if_info * if_info)
{
  if (!noce_simple_bbs (if_info))
    return FALSE;

  machine_mode mode = GET_MODE (if_info->x);
  rtx if_then_else = simplify_gen_ternary (IF_THEN_ELSE, mode, mode,
					    if_info->cond, if_info->b,
					    if_info->a);

  if (GET_CODE (if_then_else) == IF_THEN_ELSE)
    return FALSE;

  rtx_insn *seq;
  start_sequence ();
  noce_emit_move_insn (if_info->x, if_then_else);
  seq = end_ifcvt_sequence (if_info);
  if (!seq)
    return FALSE;

  emit_insn_before_setloc (seq, if_info->jump,
			  INSN_LOCATION (if_info->insn_a));

  if_info->transform_name = "noce_try_ifelse_collapse";
  return TRUE;
}


/* Convert "if (test) x = 1; else x = 0".

   Only try 0 and STORE_FLAG_VALUE here.  Other combinations will be
   tried in noce_try_store_flag_constants after noce_try_cmove has had
   a go at the conversion.  */

static int
noce_try_store_flag (struct noce_if_info *if_info)
{
  int reversep;
  rtx target;
  rtx_insn *seq;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  if (CONST_INT_P (if_info->b)
      && INTVAL (if_info->b) == STORE_FLAG_VALUE
      && if_info->a == const0_rtx)
    reversep = 0;
  else if (if_info->b == const0_rtx
	   && CONST_INT_P (if_info->a)
	   && INTVAL (if_info->a) == STORE_FLAG_VALUE
	   && (reversed_comparison_code (if_info->cond, if_info->jump)
	       != UNKNOWN))
    reversep = 1;
  else
    return FALSE;

  start_sequence ();

  target = noce_emit_store_flag (if_info, if_info->x, reversep, 0);
  if (target)
    {
      if (target != if_info->x)
	noce_emit_move_insn (if_info->x, target);

      seq = end_ifcvt_sequence (if_info);
      if (! seq)
	return FALSE;

      emit_insn_before_setloc (seq, if_info->jump,
			       INSN_LOCATION (if_info->insn_a));
      if_info->transform_name = "noce_try_store_flag";
      return TRUE;
    }
  else
    {
      end_sequence ();
      return FALSE;
    }
}


/* Convert "if (test) x = -A; else x = A" into
   x = A; if (test) x = -x if the machine can do the
   conditional negate form of this cheaply.
   Try this before noce_try_cmove that will just load the
   immediates into two registers and do a conditional select
   between them.  If the target has a conditional negate or
   conditional invert operation we can save a potentially
   expensive constant synthesis.  */

static bool
noce_try_inverse_constants (struct noce_if_info *if_info)
{
  if (!noce_simple_bbs (if_info))
    return false;

  if (!CONST_INT_P (if_info->a)
      || !CONST_INT_P (if_info->b)
      || !REG_P (if_info->x))
    return false;

  machine_mode mode = GET_MODE (if_info->x);

  HOST_WIDE_INT val_a = INTVAL (if_info->a);
  HOST_WIDE_INT val_b = INTVAL (if_info->b);

  rtx cond = if_info->cond;

  rtx x = if_info->x;
  rtx target;

  start_sequence ();

  rtx_code code;
  if (val_b != HOST_WIDE_INT_MIN && val_a == -val_b)
    code = NEG;
  else if (val_a == ~val_b)
    code = NOT;
  else
    {
      end_sequence ();
      return false;
    }

  rtx tmp = gen_reg_rtx (mode);
  noce_emit_move_insn (tmp, if_info->a);

  target = emit_conditional_neg_or_complement (x, code, mode, cond, tmp, tmp);

  if (target)
    {
      rtx_insn *seq = get_insns ();

      if (!seq)
	{
	  end_sequence ();
	  return false;
	}

      if (target != if_info->x)
	noce_emit_move_insn (if_info->x, target);

      seq = end_ifcvt_sequence (if_info);

      if (!seq)
	return false;

      emit_insn_before_setloc (seq, if_info->jump,
			       INSN_LOCATION (if_info->insn_a));
      if_info->transform_name = "noce_try_inverse_constants";
      return true;
    }

  end_sequence ();
  return false;
}


/* Convert "if (test) x = a; else x = b", for A and B constant.
   Also allow A = y + c1, B = y + c2, with a common y between A
   and B.  */

static int
noce_try_store_flag_constants (struct noce_if_info *if_info)
{
  rtx target;
  rtx_insn *seq;
  bool reversep;
  HOST_WIDE_INT itrue, ifalse, diff, tmp;
  int normalize;
  bool can_reverse;
  machine_mode mode = GET_MODE (if_info->x);;
  rtx common = NULL_RTX;

  rtx a = if_info->a;
  rtx b = if_info->b;

  /* Handle cases like x := test ? y + 3 : y + 4.  */
  if (GET_CODE (a) == PLUS
      && GET_CODE (b) == PLUS
      && CONST_INT_P (XEXP (a, 1))
      && CONST_INT_P (XEXP (b, 1))
      && rtx_equal_p (XEXP (a, 0), XEXP (b, 0))
      /* Allow expressions that are not using the result or plain
         registers where we handle overlap below.  */
      && (REG_P (XEXP (a, 0))
	  || (noce_operand_ok (XEXP (a, 0))
	      && ! reg_overlap_mentioned_p (if_info->x, XEXP (a, 0)))))
    {
      common = XEXP (a, 0);
      a = XEXP (a, 1);
      b = XEXP (b, 1);
    }

  if (!noce_simple_bbs (if_info))
    return FALSE;

  if (CONST_INT_P (a)
      && CONST_INT_P (b))
    {
      ifalse = INTVAL (a);
      itrue = INTVAL (b);
      bool subtract_flag_p = false;

      diff = (unsigned HOST_WIDE_INT) itrue - ifalse;
      /* Make sure we can represent the difference between the two values.  */
      if ((diff > 0)
	  != ((ifalse < 0) != (itrue < 0) ? ifalse < 0 : ifalse < itrue))
	return FALSE;

      diff = trunc_int_for_mode (diff, mode);

      can_reverse = (reversed_comparison_code (if_info->cond, if_info->jump)
		     != UNKNOWN);

      reversep = false;
      if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
	{
	  normalize = 0;
	  /* We could collapse these cases but it is easier to follow the
	     diff/STORE_FLAG_VALUE combinations when they are listed
	     explicitly.  */

	  /* test ? 3 : 4
	     => 4 + (test != 0).  */
	  if (diff < 0 && STORE_FLAG_VALUE < 0)
	      reversep = false;
	  /* test ? 4 : 3
	     => can_reverse  | 4 + (test == 0)
		!can_reverse | 3 - (test != 0).  */
	  else if (diff > 0 && STORE_FLAG_VALUE < 0)
	    {
	      reversep = can_reverse;
	      subtract_flag_p = !can_reverse;
	      /* If we need to subtract the flag and we have PLUS-immediate
		 A and B then it is unlikely to be beneficial to play tricks
		 here.  */
	      if (subtract_flag_p && common)
		return FALSE;
	    }
	  /* test ? 3 : 4
	     => can_reverse  | 3 + (test == 0)
		!can_reverse | 4 - (test != 0).  */
	  else if (diff < 0 && STORE_FLAG_VALUE > 0)
	    {
	      reversep = can_reverse;
	      subtract_flag_p = !can_reverse;
	      /* If we need to subtract the flag and we have PLUS-immediate
		 A and B then it is unlikely to be beneficial to play tricks
		 here.  */
	      if (subtract_flag_p && common)
		return FALSE;
	    }
	  /* test ? 4 : 3
	     => 4 + (test != 0).  */
	  else if (diff > 0 && STORE_FLAG_VALUE > 0)
	    reversep = false;
	  else
	    gcc_unreachable ();
	}
      /* Is this (cond) ? 2^n : 0?  */
      else if (ifalse == 0 && pow2p_hwi (itrue)
	       && STORE_FLAG_VALUE == 1)
	normalize = 1;
      /* Is this (cond) ? 0 : 2^n?  */
      else if (itrue == 0 && pow2p_hwi (ifalse) && can_reverse
	       && STORE_FLAG_VALUE == 1)
	{
	  normalize = 1;
	  reversep = true;
	}
      /* Is this (cond) ? -1 : x?  */
      else if (itrue == -1
	       && STORE_FLAG_VALUE == -1)
	normalize = -1;
      /* Is this (cond) ? x : -1?  */
      else if (ifalse == -1 && can_reverse
	       && STORE_FLAG_VALUE == -1)
	{
	  normalize = -1;
	  reversep = true;
	}
      else
	return FALSE;

      if (reversep)
	{
	  std::swap (itrue, ifalse);
	  diff = trunc_int_for_mode (-(unsigned HOST_WIDE_INT) diff, mode);
	}

      start_sequence ();

      /* If we have x := test ? x + 3 : x + 4 then move the original
	 x out of the way while we store flags.  */
      if (common && rtx_equal_p (common, if_info->x))
	{
	  common = gen_reg_rtx (mode);
	  noce_emit_move_insn (common, if_info->x);
	}

      target = noce_emit_store_flag (if_info, if_info->x, reversep, normalize);
      if (! target)
	{
	  end_sequence ();
	  return FALSE;
	}

      /* if (test) x = 3; else x = 4;
	 =>   x = 3 + (test == 0);  */
      if (diff == STORE_FLAG_VALUE || diff == -STORE_FLAG_VALUE)
	{
	  /* Add the common part now.  This may allow combine to merge this
	     with the store flag operation earlier into some sort of conditional
	     increment/decrement if the target allows it.  */
	  if (common)
	    target = expand_simple_binop (mode, PLUS,
					   target, common,
					   target, 0, OPTAB_WIDEN);

	  /* Always use ifalse here.  It should have been swapped with itrue
	     when appropriate when reversep is true.  */
	  target = expand_simple_binop (mode, subtract_flag_p ? MINUS : PLUS,
					gen_int_mode (ifalse, mode), target,
					if_info->x, 0, OPTAB_WIDEN);
	}
      /* Other cases are not beneficial when the original A and B are PLUS
	 expressions.  */
      else if (common)
	{
	  end_sequence ();
	  return FALSE;
	}
      /* if (test) x = 8; else x = 0;
	 =>   x = (test != 0) << 3;  */
      else if (ifalse == 0 && (tmp = exact_log2 (itrue)) >= 0)
	{
	  target = expand_simple_binop (mode, ASHIFT,
					target, GEN_INT (tmp), if_info->x, 0,
					OPTAB_WIDEN);
	}

      /* if (test) x = -1; else x = b;
	 =>   x = -(test != 0) | b;  */
      else if (itrue == -1)
	{
	  target = expand_simple_binop (mode, IOR,
					target, gen_int_mode (ifalse, mode),
					if_info->x, 0, OPTAB_WIDEN);
	}
      else
	{
	  end_sequence ();
	  return FALSE;
	}

      if (! target)
	{
	  end_sequence ();
	  return FALSE;
	}

      if (target != if_info->x)
	noce_emit_move_insn (if_info->x, target);

      seq = end_ifcvt_sequence (if_info);
      if (!seq || !noce_conversion_profitable_p (seq, if_info))
	return FALSE;

      emit_insn_before_setloc (seq, if_info->jump,
			       INSN_LOCATION (if_info->insn_a));
      if_info->transform_name = "noce_try_store_flag_constants";

      return TRUE;
    }

  return FALSE;
}

/* Convert "if (test) foo++" into "foo += (test != 0)", and
   similarly for "foo--".  */

static int
noce_try_addcc (struct noce_if_info *if_info)
{
  rtx target;
  rtx_insn *seq;
  int subtract, normalize;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  if (GET_CODE (if_info->a) == PLUS
      && rtx_equal_p (XEXP (if_info->a, 0), if_info->b)
      && (reversed_comparison_code (if_info->cond, if_info->jump)
	  != UNKNOWN))
    {
      rtx cond = if_info->cond;
      enum rtx_code code = reversed_comparison_code (cond, if_info->jump);

      /* First try to use addcc pattern.  */
      if (general_operand (XEXP (cond, 0), VOIDmode)
	  && general_operand (XEXP (cond, 1), VOIDmode))
	{
	  start_sequence ();
	  target = emit_conditional_add (if_info->x, code,
					 XEXP (cond, 0),
					 XEXP (cond, 1),
					 VOIDmode,
					 if_info->b,
					 XEXP (if_info->a, 1),
					 GET_MODE (if_info->x),
					 (code == LTU || code == GEU
					  || code == LEU || code == GTU));
	  if (target)
	    {
	      if (target != if_info->x)
		noce_emit_move_insn (if_info->x, target);

	      seq = end_ifcvt_sequence (if_info);
	      if (!seq || !noce_conversion_profitable_p (seq, if_info))
		return FALSE;

	      emit_insn_before_setloc (seq, if_info->jump,
				       INSN_LOCATION (if_info->insn_a));
	      if_info->transform_name = "noce_try_addcc";

	      return TRUE;
	    }
	  end_sequence ();
	}

      /* If that fails, construct conditional increment or decrement using
	 setcc.  We're changing a branch and an increment to a comparison and
	 an ADD/SUB.  */
      if (XEXP (if_info->a, 1) == const1_rtx
	  || XEXP (if_info->a, 1) == constm1_rtx)
        {
	  start_sequence ();
	  if (STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
	    subtract = 0, normalize = 0;
	  else if (-STORE_FLAG_VALUE == INTVAL (XEXP (if_info->a, 1)))
	    subtract = 1, normalize = 0;
	  else
	    subtract = 0, normalize = INTVAL (XEXP (if_info->a, 1));


	  target = noce_emit_store_flag (if_info,
					 gen_reg_rtx (GET_MODE (if_info->x)),
					 1, normalize);

	  if (target)
	    target = expand_simple_binop (GET_MODE (if_info->x),
					  subtract ? MINUS : PLUS,
					  if_info->b, target, if_info->x,
					  0, OPTAB_WIDEN);
	  if (target)
	    {
	      if (target != if_info->x)
		noce_emit_move_insn (if_info->x, target);

	      seq = end_ifcvt_sequence (if_info);
	      if (!seq || !noce_conversion_profitable_p (seq, if_info))
		return FALSE;

	      emit_insn_before_setloc (seq, if_info->jump,
				       INSN_LOCATION (if_info->insn_a));
	      if_info->transform_name = "noce_try_addcc";
	      return TRUE;
	    }
	  end_sequence ();
	}
    }

  return FALSE;
}

/* Convert "if (test) x = 0;" to "x &= -(test == 0);"  */

static int
noce_try_store_flag_mask (struct noce_if_info *if_info)
{
  rtx target;
  rtx_insn *seq;
  int reversep;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  reversep = 0;

  if ((if_info->a == const0_rtx
       && rtx_equal_p (if_info->b, if_info->x))
      || ((reversep = (reversed_comparison_code (if_info->cond,
						 if_info->jump)
		       != UNKNOWN))
	  && if_info->b == const0_rtx
	  && rtx_equal_p (if_info->a, if_info->x)))
    {
      start_sequence ();
      target = noce_emit_store_flag (if_info,
				     gen_reg_rtx (GET_MODE (if_info->x)),
				     reversep, -1);
      if (target)
        target = expand_simple_binop (GET_MODE (if_info->x), AND,
				      if_info->x,
				      target, if_info->x, 0,
				      OPTAB_WIDEN);

      if (target)
	{
	  if (target != if_info->x)
	    noce_emit_move_insn (if_info->x, target);

	  seq = end_ifcvt_sequence (if_info);
	  if (!seq || !noce_conversion_profitable_p (seq, if_info))
	    return FALSE;

	  emit_insn_before_setloc (seq, if_info->jump,
				   INSN_LOCATION (if_info->insn_a));
	  if_info->transform_name = "noce_try_store_flag_mask";

	  return TRUE;
	}

      end_sequence ();
    }

  return FALSE;
}

/* Helper function for noce_try_cmove and noce_try_cmove_arith.  */

static rtx
noce_emit_cmove (struct noce_if_info *if_info, rtx x, enum rtx_code code,
		 rtx cmp_a, rtx cmp_b, rtx vfalse, rtx vtrue)
{
  rtx target ATTRIBUTE_UNUSED;
  int unsignedp ATTRIBUTE_UNUSED;

  /* If earliest == jump, try to build the cmove insn directly.
     This is helpful when combine has created some complex condition
     (like for alpha's cmovlbs) that we can't hope to regenerate
     through the normal interface.  */

  if (if_info->cond_earliest == if_info->jump)
    {
      rtx cond = gen_rtx_fmt_ee (code, GET_MODE (if_info->cond), cmp_a, cmp_b);
      rtx if_then_else = gen_rtx_IF_THEN_ELSE (GET_MODE (x),
					       cond, vtrue, vfalse);
      rtx set = gen_rtx_SET (x, if_then_else);

      start_sequence ();
      rtx_insn *insn = emit_insn (set);

      if (recog_memoized (insn) >= 0)
	{
	  rtx_insn *seq = get_insns ();
	  end_sequence ();
	  emit_insn (seq);

	  return x;
	}

      end_sequence ();
    }

  /* Don't even try if the comparison operands are weird
     except that the target supports cbranchcc4.  */
  if (! general_operand (cmp_a, GET_MODE (cmp_a))
      || ! general_operand (cmp_b, GET_MODE (cmp_b)))
    {
      if (!have_cbranchcc4
	  || GET_MODE_CLASS (GET_MODE (cmp_a)) != MODE_CC
	  || cmp_b != const0_rtx)
	return NULL_RTX;
    }

  unsignedp = (code == LTU || code == GEU
	       || code == LEU || code == GTU);

  target = emit_conditional_move (x, code, cmp_a, cmp_b, VOIDmode,
				  vtrue, vfalse, GET_MODE (x),
				  unsignedp);
  if (target)
    return target;

  /* We might be faced with a situation like:

     x = (reg:M TARGET)
     vtrue = (subreg:M (reg:N VTRUE) BYTE)
     vfalse = (subreg:M (reg:N VFALSE) BYTE)

     We can't do a conditional move in mode M, but it's possible that we
     could do a conditional move in mode N instead and take a subreg of
     the result.

     If we can't create new pseudos, though, don't bother.  */
  if (reload_completed)
    return NULL_RTX;

  if (GET_CODE (vtrue) == SUBREG && GET_CODE (vfalse) == SUBREG)
    {
      rtx reg_vtrue = SUBREG_REG (vtrue);
      rtx reg_vfalse = SUBREG_REG (vfalse);
      unsigned int byte_vtrue = SUBREG_BYTE (vtrue);
      unsigned int byte_vfalse = SUBREG_BYTE (vfalse);
      rtx promoted_target;

      if (GET_MODE (reg_vtrue) != GET_MODE (reg_vfalse)
	  || byte_vtrue != byte_vfalse
	  || (SUBREG_PROMOTED_VAR_P (vtrue)
	      != SUBREG_PROMOTED_VAR_P (vfalse))
	  || (SUBREG_PROMOTED_GET (vtrue)
	      != SUBREG_PROMOTED_GET (vfalse)))
	return NULL_RTX;

      promoted_target = gen_reg_rtx (GET_MODE (reg_vtrue));

      target = emit_conditional_move (promoted_target, code, cmp_a, cmp_b,
				      VOIDmode, reg_vtrue, reg_vfalse,
				      GET_MODE (reg_vtrue), unsignedp);
      /* Nope, couldn't do it in that mode either.  */
      if (!target)
	return NULL_RTX;

      target = gen_rtx_SUBREG (GET_MODE (vtrue), promoted_target, byte_vtrue);
      SUBREG_PROMOTED_VAR_P (target) = SUBREG_PROMOTED_VAR_P (vtrue);
      SUBREG_PROMOTED_SET (target, SUBREG_PROMOTED_GET (vtrue));
      emit_move_insn (x, target);
      return x;
    }
  else
    return NULL_RTX;
}

/* Try only simple constants and registers here.  More complex cases
   are handled in noce_try_cmove_arith after noce_try_store_flag_arith
   has had a go at it.  */

static int
noce_try_cmove (struct noce_if_info *if_info)
{
  enum rtx_code code;
  rtx target;
  rtx_insn *seq;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  if ((CONSTANT_P (if_info->a) || register_operand (if_info->a, VOIDmode))
      && (CONSTANT_P (if_info->b) || register_operand (if_info->b, VOIDmode)))
    {
      start_sequence ();

      code = GET_CODE (if_info->cond);
      target = noce_emit_cmove (if_info, if_info->x, code,
				XEXP (if_info->cond, 0),
				XEXP (if_info->cond, 1),
				if_info->a, if_info->b);

      if (target)
	{
	  if (target != if_info->x)
	    noce_emit_move_insn (if_info->x, target);

	  seq = end_ifcvt_sequence (if_info);
	  if (!seq)
	    return FALSE;

	  emit_insn_before_setloc (seq, if_info->jump,
				   INSN_LOCATION (if_info->insn_a));
	  if_info->transform_name = "noce_try_cmove";

	  return TRUE;
	}
      /* If both a and b are constants try a last-ditch transformation:
	 if (test) x = a; else x = b;
	 =>   x = (-(test != 0) & (b - a)) + a;
	 Try this only if the target-specific expansion above has failed.
	 The target-specific expander may want to generate sequences that
	 we don't know about, so give them a chance before trying this
	 approach.  */
      else if (!targetm.have_conditional_execution ()
		&& CONST_INT_P (if_info->a) && CONST_INT_P (if_info->b))
	{
	  machine_mode mode = GET_MODE (if_info->x);
	  HOST_WIDE_INT ifalse = INTVAL (if_info->a);
	  HOST_WIDE_INT itrue = INTVAL (if_info->b);
	  rtx target = noce_emit_store_flag (if_info, if_info->x, false, -1);
	  if (!target)
	    {
	      end_sequence ();
	      return FALSE;
	    }

	  HOST_WIDE_INT diff = (unsigned HOST_WIDE_INT) itrue - ifalse;
	  /* Make sure we can represent the difference
	     between the two values.  */
	  if ((diff > 0)
	      != ((ifalse < 0) != (itrue < 0) ? ifalse < 0 : ifalse < itrue))
	    {
	      end_sequence ();
	      return FALSE;
	    }

	  diff = trunc_int_for_mode (diff, mode);
	  target = expand_simple_binop (mode, AND,
					target, gen_int_mode (diff, mode),
					if_info->x, 0, OPTAB_WIDEN);
	  if (target)
	    target = expand_simple_binop (mode, PLUS,
					  target, gen_int_mode (ifalse, mode),
					  if_info->x, 0, OPTAB_WIDEN);
	  if (target)
	    {
	      if (target != if_info->x)
		noce_emit_move_insn (if_info->x, target);

	      seq = end_ifcvt_sequence (if_info);
	      if (!seq || !noce_conversion_profitable_p (seq, if_info))
		return FALSE;

	      emit_insn_before_setloc (seq, if_info->jump,
				   INSN_LOCATION (if_info->insn_a));
	      if_info->transform_name = "noce_try_cmove";
	      return TRUE;
	    }
	  else
	    {
	      end_sequence ();
	      return FALSE;
	    }
	}
      else
	end_sequence ();
    }

  return FALSE;
}

/* Return true if X contains a conditional code mode rtx.  */

static bool
contains_ccmode_rtx_p (rtx x)
{
  subrtx_iterator::array_type array;
  FOR_EACH_SUBRTX (iter, array, x, ALL)
    if (GET_MODE_CLASS (GET_MODE (*iter)) == MODE_CC)
      return true;

  return false;
}

/* Helper for bb_valid_for_noce_process_p.  Validate that
   the rtx insn INSN is a single set that does not set
   the conditional register CC and is in general valid for
   if-conversion.  */

static bool
insn_valid_noce_process_p (rtx_insn *insn, rtx cc)
{
  if (!insn
      || !NONJUMP_INSN_P (insn)
      || (cc && set_of (cc, insn)))
      return false;

  rtx sset = single_set (insn);

  /* Currently support only simple single sets in test_bb.  */
  if (!sset
      || !noce_operand_ok (SET_DEST (sset))
      || contains_ccmode_rtx_p (SET_DEST (sset))
      || !noce_operand_ok (SET_SRC (sset)))
    return false;

  return true;
}


/* Return true iff the registers that the insns in BB_A set do not get
   used in BB_B.  If TO_RENAME is non-NULL then it is a location that will be
   renamed later by the caller and so conflicts on it should be ignored
   in this function.  */

static bool
bbs_ok_for_cmove_arith (basic_block bb_a, basic_block bb_b, rtx to_rename)
{
  rtx_insn *a_insn;
  bitmap bba_sets = BITMAP_ALLOC (&reg_obstack);

  df_ref def;
  df_ref use;

  FOR_BB_INSNS (bb_a, a_insn)
    {
      if (!active_insn_p (a_insn))
	continue;

      rtx sset_a = single_set (a_insn);

      if (!sset_a)
	{
	  BITMAP_FREE (bba_sets);
	  return false;
	}
      /* Record all registers that BB_A sets.  */
      FOR_EACH_INSN_DEF (def, a_insn)
	if (!(to_rename && DF_REF_REG (def) == to_rename))
	  bitmap_set_bit (bba_sets, DF_REF_REGNO (def));
    }

  rtx_insn *b_insn;

  FOR_BB_INSNS (bb_b, b_insn)
    {
      if (!active_insn_p (b_insn))
	continue;

      rtx sset_b = single_set (b_insn);

      if (!sset_b)
	{
	  BITMAP_FREE (bba_sets);
	  return false;
	}

      /* Make sure this is a REG and not some instance
	 of ZERO_EXTRACT or SUBREG or other dangerous stuff.
	 If we have a memory destination then we have a pair of simple
	 basic blocks performing an operation of the form [addr] = c ? a : b.
	 bb_valid_for_noce_process_p will have ensured that these are
	 the only stores present.  In that case [addr] should be the location
	 to be renamed.  Assert that the callers set this up properly.  */
      if (MEM_P (SET_DEST (sset_b)))
	gcc_assert (rtx_equal_p (SET_DEST (sset_b), to_rename));
      else if (!REG_P (SET_DEST (sset_b)))
	{
	  BITMAP_FREE (bba_sets);
	  return false;
	}

      /* If the insn uses a reg set in BB_A return false.  */
      FOR_EACH_INSN_USE (use, b_insn)
	{
	  if (bitmap_bit_p (bba_sets, DF_REF_REGNO (use)))
	    {
	      BITMAP_FREE (bba_sets);
	      return false;
	    }
	}

    }

  BITMAP_FREE (bba_sets);
  return true;
}

/* Emit copies of all the active instructions in BB except the last.
   This is a helper for noce_try_cmove_arith.  */

static void
noce_emit_all_but_last (basic_block bb)
{
  rtx_insn *last = last_active_insn (bb, FALSE);
  rtx_insn *insn;
  FOR_BB_INSNS (bb, insn)
    {
      if (insn != last && active_insn_p (insn))
	{
	  rtx_insn *to_emit = as_a <rtx_insn *> (copy_rtx (insn));

	  emit_insn (PATTERN (to_emit));
	}
    }
}

/* Helper for noce_try_cmove_arith.  Emit the pattern TO_EMIT and return
   the resulting insn or NULL if it's not a valid insn.  */

static rtx_insn *
noce_emit_insn (rtx to_emit)
{
  gcc_assert (to_emit);
  rtx_insn *insn = emit_insn (to_emit);

  if (recog_memoized (insn) < 0)
    return NULL;

  return insn;
}

/* Helper for noce_try_cmove_arith.  Emit a copy of the insns up to
   and including the penultimate one in BB if it is not simple
   (as indicated by SIMPLE).  Then emit LAST_INSN as the last
   insn in the block.  The reason for that is that LAST_INSN may
   have been modified by the preparation in noce_try_cmove_arith.  */

static bool
noce_emit_bb (rtx last_insn, basic_block bb, bool simple)
{
  if (bb && !simple)
    noce_emit_all_but_last (bb);

  if (last_insn && !noce_emit_insn (last_insn))
    return false;

  return true;
}

/* Try more complex cases involving conditional_move.  */

static int
noce_try_cmove_arith (struct noce_if_info *if_info)
{
  rtx a = if_info->a;
  rtx b = if_info->b;
  rtx x = if_info->x;
  rtx orig_a, orig_b;
  rtx_insn *insn_a, *insn_b;
  bool a_simple = if_info->then_simple;
  bool b_simple = if_info->else_simple;
  basic_block then_bb = if_info->then_bb;
  basic_block else_bb = if_info->else_bb;
  rtx target;
  int is_mem = 0;
  enum rtx_code code;
  rtx_insn *ifcvt_seq;

  /* A conditional move from two memory sources is equivalent to a
     conditional on their addresses followed by a load.  Don't do this
     early because it'll screw alias analysis.  Note that we've
     already checked for no side effects.  */
  if (cse_not_expected
      && MEM_P (a) && MEM_P (b)
      && MEM_ADDR_SPACE (a) == MEM_ADDR_SPACE (b))
    {
      machine_mode address_mode = get_address_mode (a);

      a = XEXP (a, 0);
      b = XEXP (b, 0);
      x = gen_reg_rtx (address_mode);
      is_mem = 1;
    }

  /* ??? We could handle this if we knew that a load from A or B could
     not trap or fault.  This is also true if we've already loaded
     from the address along the path from ENTRY.  */
  else if (may_trap_or_fault_p (a) || may_trap_or_fault_p (b))
    return FALSE;

  /* if (test) x = a + b; else x = c - d;
     => y = a + b;
        x = c - d;
	if (test)
	  x = y;
  */

  code = GET_CODE (if_info->cond);
  insn_a = if_info->insn_a;
  insn_b = if_info->insn_b;

  machine_mode x_mode = GET_MODE (x);

  if (!can_conditionally_move_p (x_mode))
    return FALSE;

  /* Possibly rearrange operands to make things come out more natural.  */
  if (reversed_comparison_code (if_info->cond, if_info->jump) != UNKNOWN)
    {
      int reversep = 0;
      if (rtx_equal_p (b, x))
	reversep = 1;
      else if (general_operand (b, GET_MODE (b)))
	reversep = 1;

      if (reversep)
	{
	  code = reversed_comparison_code (if_info->cond, if_info->jump);
	  std::swap (a, b);
	  std::swap (insn_a, insn_b);
	  std::swap (a_simple, b_simple);
	  std::swap (then_bb, else_bb);
	}
    }

  if (then_bb && else_bb
      && (!bbs_ok_for_cmove_arith (then_bb, else_bb,  if_info->orig_x)
	  || !bbs_ok_for_cmove_arith (else_bb, then_bb,  if_info->orig_x)))
    return FALSE;

  start_sequence ();

  /* If one of the blocks is empty then the corresponding B or A value
     came from the test block.  The non-empty complex block that we will
     emit might clobber the register used by B or A, so move it to a pseudo
     first.  */

  rtx tmp_a = NULL_RTX;
  rtx tmp_b = NULL_RTX;

  if (b_simple || !else_bb)
    tmp_b = gen_reg_rtx (x_mode);

  if (a_simple || !then_bb)
    tmp_a = gen_reg_rtx (x_mode);

  orig_a = a;
  orig_b = b;

  rtx emit_a = NULL_RTX;
  rtx emit_b = NULL_RTX;
  rtx_insn *tmp_insn = NULL;
  bool modified_in_a = false;
  bool  modified_in_b = false;
  /* If either operand is complex, load it into a register first.
     The best way to do this is to copy the original insn.  In this
     way we preserve any clobbers etc that the insn may have had.
     This is of course not possible in the IS_MEM case.  */

  if (! general_operand (a, GET_MODE (a)) || tmp_a)
    {

      if (is_mem)
	{
	  rtx reg = gen_reg_rtx (GET_MODE (a));
	  emit_a = gen_rtx_SET (reg, a);
	}
      else
	{
	  if (insn_a)
	    {
	      a = tmp_a ? tmp_a : gen_reg_rtx (GET_MODE (a));

	      rtx_insn *copy_of_a = as_a <rtx_insn *> (copy_rtx (insn_a));
	      rtx set = single_set (copy_of_a);
	      SET_DEST (set) = a;

	      emit_a = PATTERN (copy_of_a);
	    }
	  else
	    {
	      rtx tmp_reg = tmp_a ? tmp_a : gen_reg_rtx (GET_MODE (a));
	      emit_a = gen_rtx_SET (tmp_reg, a);
	      a = tmp_reg;
	    }
	}
    }

  if (! general_operand (b, GET_MODE (b)) || tmp_b)
    {
      if (is_mem)
	{
          rtx reg = gen_reg_rtx (GET_MODE (b));
	  emit_b = gen_rtx_SET (reg, b);
	}
      else
	{
	  if (insn_b)
	    {
	      b = tmp_b ? tmp_b : gen_reg_rtx (GET_MODE (b));
	      rtx_insn *copy_of_b = as_a <rtx_insn *> (copy_rtx (insn_b));
	      rtx set = single_set (copy_of_b);

	      SET_DEST (set) = b;
	      emit_b = PATTERN (copy_of_b);
	    }
	  else
	    {
	      rtx tmp_reg = tmp_b ? tmp_b : gen_reg_rtx (GET_MODE (b));
	      emit_b = gen_rtx_SET (tmp_reg, b);
	      b = tmp_reg;
	  }
	}
    }

  modified_in_a = emit_a != NULL_RTX && modified_in_p (orig_b, emit_a);
  if (tmp_b && then_bb)
    {
      FOR_BB_INSNS (then_bb, tmp_insn)
	/* Don't check inside insn_a.  We will have changed it to emit_a
	   with a destination that doesn't conflict.  */
	if (!(insn_a && tmp_insn == insn_a)
	    && modified_in_p (orig_b, tmp_insn))
	  {
	    modified_in_a = true;
	    break;
	  }

    }

  modified_in_b = emit_b != NULL_RTX && modified_in_p (orig_a, emit_b);
  if (tmp_a && else_bb)
    {
      FOR_BB_INSNS (else_bb, tmp_insn)
      /* Don't check inside insn_b.  We will have changed it to emit_b
	 with a destination that doesn't conflict.  */
      if (!(insn_b && tmp_insn == insn_b)
	  && modified_in_p (orig_a, tmp_insn))
	{
	  modified_in_b = true;
	  break;
	}
    }

  /* If insn to set up A clobbers any registers B depends on, try to
     swap insn that sets up A with the one that sets up B.  If even
     that doesn't help, punt.  */
  if (modified_in_a && !modified_in_b)
    {
      if (!noce_emit_bb (emit_b, else_bb, b_simple))
	goto end_seq_and_fail;

      if (!noce_emit_bb (emit_a, then_bb, a_simple))
	goto end_seq_and_fail;
    }
  else if (!modified_in_a)
    {
      if (!noce_emit_bb (emit_a, then_bb, a_simple))
	goto end_seq_and_fail;

      if (!noce_emit_bb (emit_b, else_bb, b_simple))
	goto end_seq_and_fail;
    }
  else
    goto end_seq_and_fail;

  target = noce_emit_cmove (if_info, x, code, XEXP (if_info->cond, 0),
			    XEXP (if_info->cond, 1), a, b);

  if (! target)
    goto end_seq_and_fail;

  /* If we're handling a memory for above, emit the load now.  */
  if (is_mem)
    {
      rtx mem = gen_rtx_MEM (GET_MODE (if_info->x), target);

      /* Copy over flags as appropriate.  */
      if (MEM_VOLATILE_P (if_info->a) || MEM_VOLATILE_P (if_info->b))
	MEM_VOLATILE_P (mem) = 1;
      if (MEM_ALIAS_SET (if_info->a) == MEM_ALIAS_SET (if_info->b))
	set_mem_alias_set (mem, MEM_ALIAS_SET (if_info->a));
      set_mem_align (mem,
		     MIN (MEM_ALIGN (if_info->a), MEM_ALIGN (if_info->b)));

      gcc_assert (MEM_ADDR_SPACE (if_info->a) == MEM_ADDR_SPACE (if_info->b));
      set_mem_addr_space (mem, MEM_ADDR_SPACE (if_info->a));

      noce_emit_move_insn (if_info->x, mem);
    }
  else if (target != x)
    noce_emit_move_insn (x, target);

  ifcvt_seq = end_ifcvt_sequence (if_info);
  if (!ifcvt_seq || !noce_conversion_profitable_p (ifcvt_seq, if_info))
    return FALSE;

  emit_insn_before_setloc (ifcvt_seq, if_info->jump,
			   INSN_LOCATION (if_info->insn_a));
  if_info->transform_name = "noce_try_cmove_arith";
  return TRUE;

 end_seq_and_fail:
  end_sequence ();
  return FALSE;
}

/* For most cases, the simplified condition we found is the best
   choice, but this is not the case for the min/max/abs transforms.
   For these we wish to know that it is A or B in the condition.  */

static rtx
noce_get_alt_condition (struct noce_if_info *if_info, rtx target,
			rtx_insn **earliest)
{
  rtx cond, set;
  rtx_insn *insn;
  int reverse;

  /* If target is already mentioned in the known condition, return it.  */
  if (reg_mentioned_p (target, if_info->cond))
    {
      *earliest = if_info->cond_earliest;
      return if_info->cond;
    }

  set = pc_set (if_info->jump);
  cond = XEXP (SET_SRC (set), 0);
  reverse
    = GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
      && LABEL_REF_LABEL (XEXP (SET_SRC (set), 2)) == JUMP_LABEL (if_info->jump);
  if (if_info->then_else_reversed)
    reverse = !reverse;

  /* If we're looking for a constant, try to make the conditional
     have that constant in it.  There are two reasons why it may
     not have the constant we want:

     1. GCC may have needed to put the constant in a register, because
        the target can't compare directly against that constant.  For
        this case, we look for a SET immediately before the comparison
        that puts a constant in that register.

     2. GCC may have canonicalized the conditional, for example
	replacing "if x < 4" with "if x <= 3".  We can undo that (or
	make equivalent types of changes) to get the constants we need
	if they're off by one in the right direction.  */

  if (CONST_INT_P (target))
    {
      enum rtx_code code = GET_CODE (if_info->cond);
      rtx op_a = XEXP (if_info->cond, 0);
      rtx op_b = XEXP (if_info->cond, 1);
      rtx_insn *prev_insn;

      /* First, look to see if we put a constant in a register.  */
      prev_insn = prev_nonnote_insn (if_info->cond_earliest);
      if (prev_insn
	  && BLOCK_FOR_INSN (prev_insn)
	     == BLOCK_FOR_INSN (if_info->cond_earliest)
	  && INSN_P (prev_insn)
	  && GET_CODE (PATTERN (prev_insn)) == SET)
	{
	  rtx src = find_reg_equal_equiv_note (prev_insn);
	  if (!src)
	    src = SET_SRC (PATTERN (prev_insn));
	  if (CONST_INT_P (src))
	    {
	      if (rtx_equal_p (op_a, SET_DEST (PATTERN (prev_insn))))
		op_a = src;
	      else if (rtx_equal_p (op_b, SET_DEST (PATTERN (prev_insn))))
		op_b = src;

	      if (CONST_INT_P (op_a))
		{
		  std::swap (op_a, op_b);
		  code = swap_condition (code);
		}
	    }
	}

      /* Now, look to see if we can get the right constant by
	 adjusting the conditional.  */
      if (CONST_INT_P (op_b))
	{
	  HOST_WIDE_INT desired_val = INTVAL (target);
	  HOST_WIDE_INT actual_val = INTVAL (op_b);

	  switch (code)
	    {
	    case LT:
	      if (desired_val != HOST_WIDE_INT_MAX
		  && actual_val == desired_val + 1)
		{
		  code = LE;
		  op_b = GEN_INT (desired_val);
		}
	      break;
	    case LE:
	      if (desired_val != HOST_WIDE_INT_MIN
		  && actual_val == desired_val - 1)
		{
		  code = LT;
		  op_b = GEN_INT (desired_val);
		}
	      break;
	    case GT:
	      if (desired_val != HOST_WIDE_INT_MIN
		  && actual_val == desired_val - 1)
		{
		  code = GE;
		  op_b = GEN_INT (desired_val);
		}
	      break;
	    case GE:
	      if (desired_val != HOST_WIDE_INT_MAX
		  && actual_val == desired_val + 1)
		{
		  code = GT;
		  op_b = GEN_INT (desired_val);
		}
	      break;
	    default:
	      break;
	    }
	}

      /* If we made any changes, generate a new conditional that is
	 equivalent to what we started with, but has the right
	 constants in it.  */
      if (code != GET_CODE (if_info->cond)
	  || op_a != XEXP (if_info->cond, 0)
	  || op_b != XEXP (if_info->cond, 1))
	{
	  cond = gen_rtx_fmt_ee (code, GET_MODE (cond), op_a, op_b);
	  *earliest = if_info->cond_earliest;
	  return cond;
	}
    }

  cond = canonicalize_condition (if_info->jump, cond, reverse,
				 earliest, target, have_cbranchcc4, true);
  if (! cond || ! reg_mentioned_p (target, cond))
    return NULL;

  /* We almost certainly searched back to a different place.
     Need to re-verify correct lifetimes.  */

  /* X may not be mentioned in the range (cond_earliest, jump].  */
  for (insn = if_info->jump; insn != *earliest; insn = PREV_INSN (insn))
    if (INSN_P (insn) && reg_overlap_mentioned_p (if_info->x, PATTERN (insn)))
      return NULL;

  /* A and B may not be modified in the range [cond_earliest, jump).  */
  for (insn = *earliest; insn != if_info->jump; insn = NEXT_INSN (insn))
    if (INSN_P (insn)
	&& (modified_in_p (if_info->a, insn)
	    || modified_in_p (if_info->b, insn)))
      return NULL;

  return cond;
}

/* Convert "if (a < b) x = a; else x = b;" to "x = min(a, b);", etc.  */

static int
noce_try_minmax (struct noce_if_info *if_info)
{
  rtx cond, target;
  rtx_insn *earliest, *seq;
  enum rtx_code code, op;
  int unsignedp;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  /* ??? Reject modes with NaNs or signed zeros since we don't know how
     they will be resolved with an SMIN/SMAX.  It wouldn't be too hard
     to get the target to tell us...  */
  if (HONOR_SIGNED_ZEROS (if_info->x)
      || HONOR_NANS (if_info->x))
    return FALSE;

  cond = noce_get_alt_condition (if_info, if_info->a, &earliest);
  if (!cond)
    return FALSE;

  /* Verify the condition is of the form we expect, and canonicalize
     the comparison code.  */
  code = GET_CODE (cond);
  if (rtx_equal_p (XEXP (cond, 0), if_info->a))
    {
      if (! rtx_equal_p (XEXP (cond, 1), if_info->b))
	return FALSE;
    }
  else if (rtx_equal_p (XEXP (cond, 1), if_info->a))
    {
      if (! rtx_equal_p (XEXP (cond, 0), if_info->b))
	return FALSE;
      code = swap_condition (code);
    }
  else
    return FALSE;

  /* Determine what sort of operation this is.  Note that the code is for
     a taken branch, so the code->operation mapping appears backwards.  */
  switch (code)
    {
    case LT:
    case LE:
    case UNLT:
    case UNLE:
      op = SMAX;
      unsignedp = 0;
      break;
    case GT:
    case GE:
    case UNGT:
    case UNGE:
      op = SMIN;
      unsignedp = 0;
      break;
    case LTU:
    case LEU:
      op = UMAX;
      unsignedp = 1;
      break;
    case GTU:
    case GEU:
      op = UMIN;
      unsignedp = 1;
      break;
    default:
      return FALSE;
    }

  start_sequence ();

  target = expand_simple_binop (GET_MODE (if_info->x), op,
				if_info->a, if_info->b,
				if_info->x, unsignedp, OPTAB_WIDEN);
  if (! target)
    {
      end_sequence ();
      return FALSE;
    }
  if (target != if_info->x)
    noce_emit_move_insn (if_info->x, target);

  seq = end_ifcvt_sequence (if_info);
  if (!seq)
    return FALSE;

  emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATION (if_info->insn_a));
  if_info->cond = cond;
  if_info->cond_earliest = earliest;
  if_info->transform_name = "noce_try_minmax";

  return TRUE;
}

/* Convert "if (a < 0) x = -a; else x = a;" to "x = abs(a);",
   "if (a < 0) x = ~a; else x = a;" to "x = one_cmpl_abs(a);",
   etc.  */

static int
noce_try_abs (struct noce_if_info *if_info)
{
  rtx cond, target, a, b, c;
  rtx_insn *earliest, *seq;
  int negate;
  bool one_cmpl = false;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  /* Reject modes with signed zeros.  */
  if (HONOR_SIGNED_ZEROS (if_info->x))
    return FALSE;

  /* Recognize A and B as constituting an ABS or NABS.  The canonical
     form is a branch around the negation, taken when the object is the
     first operand of a comparison against 0 that evaluates to true.  */
  a = if_info->a;
  b = if_info->b;
  if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
    negate = 0;
  else if (GET_CODE (b) == NEG && rtx_equal_p (XEXP (b, 0), a))
    {
      std::swap (a, b);
      negate = 1;
    }
  else if (GET_CODE (a) == NOT && rtx_equal_p (XEXP (a, 0), b))
    {
      negate = 0;
      one_cmpl = true;
    }
  else if (GET_CODE (b) == NOT && rtx_equal_p (XEXP (b, 0), a))
    {
      std::swap (a, b);
      negate = 1;
      one_cmpl = true;
    }
  else
    return FALSE;

  cond = noce_get_alt_condition (if_info, b, &earliest);
  if (!cond)
    return FALSE;

  /* Verify the condition is of the form we expect.  */
  if (rtx_equal_p (XEXP (cond, 0), b))
    c = XEXP (cond, 1);
  else if (rtx_equal_p (XEXP (cond, 1), b))
    {
      c = XEXP (cond, 0);
      negate = !negate;
    }
  else
    return FALSE;

  /* Verify that C is zero.  Search one step backward for a
     REG_EQUAL note or a simple source if necessary.  */
  if (REG_P (c))
    {
      rtx set;
      rtx_insn *insn = prev_nonnote_insn (earliest);
      if (insn
	  && BLOCK_FOR_INSN (insn) == BLOCK_FOR_INSN (earliest)
	  && (set = single_set (insn))
	  && rtx_equal_p (SET_DEST (set), c))
	{
	  rtx note = find_reg_equal_equiv_note (insn);
	  if (note)
	    c = XEXP (note, 0);
	  else
	    c = SET_SRC (set);
	}
      else
	return FALSE;
    }
  if (MEM_P (c)
      && GET_CODE (XEXP (c, 0)) == SYMBOL_REF
      && CONSTANT_POOL_ADDRESS_P (XEXP (c, 0)))
    c = get_pool_constant (XEXP (c, 0));

  /* Work around funny ideas get_condition has wrt canonicalization.
     Note that these rtx constants are known to be CONST_INT, and
     therefore imply integer comparisons.
     The one_cmpl case is more complicated, as we want to handle
     only x < 0 ? ~x : x or x >= 0 ? x : ~x to one_cmpl_abs (x)
     and x < 0 ? x : ~x or x >= 0 ? ~x : x to ~one_cmpl_abs (x),
     but not other cases (x > -1 is equivalent of x >= 0).  */
  if (c == constm1_rtx && GET_CODE (cond) == GT)
    ;
  else if (c == const1_rtx && GET_CODE (cond) == LT)
    {
      if (one_cmpl)
	return FALSE;
    }
  else if (c == CONST0_RTX (GET_MODE (b)))
    {
      if (one_cmpl
	  && GET_CODE (cond) != GE
	  && GET_CODE (cond) != LT)
	return FALSE;
    }
  else
    return FALSE;

  /* Determine what sort of operation this is.  */
  switch (GET_CODE (cond))
    {
    case LT:
    case LE:
    case UNLT:
    case UNLE:
      negate = !negate;
      break;
    case GT:
    case GE:
    case UNGT:
    case UNGE:
      break;
    default:
      return FALSE;
    }

  start_sequence ();
  if (one_cmpl)
    target = expand_one_cmpl_abs_nojump (GET_MODE (if_info->x), b,
                                         if_info->x);
  else
    target = expand_abs_nojump (GET_MODE (if_info->x), b, if_info->x, 1);

  /* ??? It's a quandary whether cmove would be better here, especially
     for integers.  Perhaps combine will clean things up.  */
  if (target && negate)
    {
      if (one_cmpl)
        target = expand_simple_unop (GET_MODE (target), NOT, target,
                                     if_info->x, 0);
      else
        target = expand_simple_unop (GET_MODE (target), NEG, target,
                                     if_info->x, 0);
    }

  if (! target)
    {
      end_sequence ();
      return FALSE;
    }

  if (target != if_info->x)
    noce_emit_move_insn (if_info->x, target);

  seq = end_ifcvt_sequence (if_info);
  if (!seq)
    return FALSE;

  emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATION (if_info->insn_a));
  if_info->cond = cond;
  if_info->cond_earliest = earliest;
  if_info->transform_name = "noce_try_abs";

  return TRUE;
}

/* Convert "if (m < 0) x = b; else x = 0;" to "x = (m >> C) & b;".  */

static int
noce_try_sign_mask (struct noce_if_info *if_info)
{
  rtx cond, t, m, c;
  rtx_insn *seq;
  machine_mode mode;
  enum rtx_code code;
  bool t_unconditional;

  if (!noce_simple_bbs (if_info))
    return FALSE;

  cond = if_info->cond;
  code = GET_CODE (cond);
  m = XEXP (cond, 0);
  c = XEXP (cond, 1);

  t = NULL_RTX;
  if (if_info->a == const0_rtx)
    {
      if ((code == LT && c == const0_rtx)
	  || (code == LE && c == constm1_rtx))
	t = if_info->b;
    }
  else if (if_info->b == const0_rtx)
    {
      if ((code == GE && c == const0_rtx)
	  || (code == GT && c == constm1_rtx))
	t = if_info->a;
    }

  if (! t || side_effects_p (t))
    return FALSE;

  /* We currently don't handle different modes.  */
  mode = GET_MODE (t);
  if (GET_MODE (m) != mode)
    return FALSE;

  /* This is only profitable if T is unconditionally executed/evaluated in the
     original insn sequence or T is cheap.  The former happens if B is the
     non-zero (T) value and if INSN_B was taken from TEST_BB, or there was no
     INSN_B which can happen for e.g. conditional stores to memory.  For the
     cost computation use the block TEST_BB where the evaluation will end up
     after the transformation.  */
  t_unconditional =
    (t == if_info->b
     && (if_info->insn_b == NULL_RTX
	 || BLOCK_FOR_INSN (if_info->insn_b) == if_info->test_bb));
  if (!(t_unconditional
	|| (set_src_cost (t, mode, if_info->speed_p)
	    < COSTS_N_INSNS (2))))
    return FALSE;

  start_sequence ();
  /* Use emit_store_flag to generate "m < 0 ? -1 : 0" instead of expanding
     "(signed) m >> 31" directly.  This benefits targets with specialized
     insns to obtain the signmask, but still uses ashr_optab otherwise.  */
  m = emit_store_flag (gen_reg_rtx (mode), LT, m, const0_rtx, mode, 0, -1);
  t = m ? expand_binop (mode, and_optab, m, t, NULL_RTX, 0, OPTAB_DIRECT)
	: NULL_RTX;

  if (!t)
    {
      end_sequence ();
      return FALSE;
    }

  noce_emit_move_insn (if_info->x, t);

  seq = end_ifcvt_sequence (if_info);
  if (!seq)
    return FALSE;

  emit_insn_before_setloc (seq, if_info->jump, INSN_LOCATION (if_info->insn_a));
  if_info->transform_name = "noce_try_sign_mask";

  return TRUE;
}


/* Optimize away "if (x & C) x |= C" and similar bit manipulation
   transformations.  */

static int
noce_try_bitop (struct noce_if_info *if_info)
{
  rtx cond, x, a, result;
  rtx_insn *seq;
  machine_mode mode;
  enum rtx_code code;
  int bitnum;

  x = if_info->x;
  cond = if_info->cond;
  code = GET_CODE (cond);

  if (!noce_simple_bbs (if_info))
    return FALSE;

  /* Check for no else condition.  */
  if (! rtx_equal_p (x, if_info->b))
    return FALSE;

  /* Check for a suitable condition.  */
  if (code != NE && code != EQ)
    return FALSE;
  if (XEXP (cond, 1) != const0_rtx)
    return FALSE;
  cond = XEXP (cond, 0);

  /* ??? We could also handle AND here.  */
  if (GET_CODE (cond) == ZERO_EXTRACT)
    {
      if (XEXP (cond, 1) != const1_rtx
	  || !CONST_INT_P (XEXP (cond, 2))
	  || ! rtx_equal_p (x, XEXP (cond, 0)))
	return FALSE;
      bitnum = INTVAL (XEXP (cond, 2));
      mode = GET_MODE (x);
      if (BITS_BIG_ENDIAN)
	bitnum = GET_MODE_BITSIZE (mode) - 1 - bitnum;
      if (bitnum < 0 || bitnum >= HOST_BITS_PER_WIDE_INT)
	return FALSE;
    }
  else
    return FALSE;

  a = if_info->a;
  if (GET_CODE (a) == IOR || GET_CODE (a) == XOR)
    {
      /* Check for "if (X & C) x = x op C".  */
      if (! rtx_equal_p (x, XEXP (a, 0))
          || !CONST_INT_P (XEXP (a, 1))
	  || (INTVAL (XEXP (a, 1)) & GET_MODE_MASK (mode))
	     != HOST_WIDE_INT_1U << bitnum)
        return FALSE;

      /* if ((x & C) == 0) x |= C; is transformed to x |= C.   */
      /* if ((x & C) != 0) x |= C; is transformed to nothing.  */
      if (GET_CODE (a) == IOR)
	result = (code == NE) ? a : NULL_RTX;
      else if (code == NE)
	{
	  /* if ((x & C) == 0) x ^= C; is transformed to x |= C.   */
	  result = gen_int_mode (HOST_WIDE_INT_1 << bitnum, mode);
	  result = simplify_gen_binary (IOR, mode, x, result);
	}
      else
	{
	  /* if ((x & C) != 0) x ^= C; is transformed to x &= ~C.  */
	  result = gen_int_mode (~(HOST_WIDE_INT_1 << bitnum), mode);
	  result = simplify_gen_binary (AND, mode, x, result);
	}
    }
  else if (GET_CODE (a) == AND)
    {
      /* Check for "if (X & C) x &= ~C".  */
      if (! rtx_equal_p (x, XEXP (a, 0))
	  || !CONST_INT_P (XEXP (a, 1))
	  || (INTVAL (XEXP (a, 1)) & GET_MODE_MASK (mode))
	     != (~(HOST_WIDE_INT_1 << bitnum) & GET_MODE_MASK (mode)))
        return FALSE;

      /* if ((x & C) == 0) x &= ~C; is transformed to nothing.  */
      /* if ((x & C) != 0) x &= ~C; is transformed to x &= ~C.  */
      result = (code == EQ) ? a : NULL_RTX;
    }
  else
    return FALSE;

  if (result)
    {
      start_sequence ();
      noce_emit_move_insn (x, result);
      seq = end_ifcvt_sequence (if_info);
      if (!seq)
	return FALSE;

      emit_insn_before_setloc (seq, if_info->jump,
			       INSN_LOCATION (if_info->insn_a));
    }
  if_info->transform_name = "noce_try_bitop";
  return TRUE;
}


/* Similar to get_condition, only the resulting condition must be
   valid at JUMP, instead of at EARLIEST.

   If THEN_ELSE_REVERSED is true, the fallthrough does not go to the
   THEN block of the caller, and we have to reverse the condition.  */

static rtx
noce_get_condition (rtx_insn *jump, rtx_insn **earliest, bool then_else_reversed)
{
  rtx cond, set, tmp;
  bool reverse;

  if (! any_condjump_p (jump))
    return NULL_RTX;

  set = pc_set (jump);

  /* If this branches to JUMP_LABEL when the condition is false,
     reverse the condition.  */
  reverse = (GET_CODE (XEXP (SET_SRC (set), 2)) == LABEL_REF
	     && LABEL_REF_LABEL (XEXP (SET_SRC (set), 2)) == JUMP_LABEL (jump));

  /* We may have to reverse because the caller's if block is not canonical,
     i.e. the THEN block isn't the fallthrough block for the TEST block
     (see find_if_header).  */
  if (then_else_reversed)
    reverse = !reverse;

  /* If the condition variable is a register and is MODE_INT, accept it.  */

  cond = XEXP (SET_SRC (set), 0);
  tmp = XEXP (cond, 0);
  if (REG_P (tmp) && GET_MODE_CLASS (GET_MODE (tmp)) == MODE_INT
      && (GET_MODE (tmp) != BImode
          || !targetm.small_register_classes_for_mode_p (BImode)))
    {
      *earliest = jump;

      if (reverse)
	cond = gen_rtx_fmt_ee (reverse_condition (GET_CODE (cond)),
			       GET_MODE (cond), tmp, XEXP (cond, 1));
      return cond;
    }

  /* Otherwise, fall back on canonicalize_condition to do the dirty
     work of manipulating MODE_CC values and COMPARE rtx codes.  */
  tmp = canonicalize_condition (jump, cond, reverse, earliest,
				NULL_RTX, have_cbranchcc4, true);

  /* We don't handle side-effects in the condition, like handling
     REG_INC notes and making sure no duplicate conditions are emitted.  */
  if (tmp != NULL_RTX && side_effects_p (tmp))
    return NULL_RTX;

  return tmp;
}

/* Return true if OP is ok for if-then-else processing.  */

static int
noce_operand_ok (const_rtx op)
{
  if (side_effects_p (op))
    return FALSE;

  /* We special-case memories, so handle any of them with
     no address side effects.  */
  if (MEM_P (op))
    return ! side_effects_p (XEXP (op, 0));

  return ! may_trap_p (op);
}

/* Return true if X contains a MEM subrtx.  */

static bool
contains_mem_rtx_p (rtx x)
{
  subrtx_iterator::array_type array;
  FOR_EACH_SUBRTX (iter, array, x, ALL)
    if (MEM_P (*iter))
      return true;

  return false;
}

/* Return true iff basic block TEST_BB is valid for noce if-conversion.
   The condition used in this if-conversion is in COND.
   In practice, check that TEST_BB ends with a single set
   x := a and all previous computations
   in TEST_BB don't produce any values that are live after TEST_BB.
   In other words, all the insns in TEST_BB are there only
   to compute a value for x.  Add the rtx cost of the insns
   in TEST_BB to COST.  Record whether TEST_BB is a single simple
   set instruction in SIMPLE_P.  */

static bool
bb_valid_for_noce_process_p (basic_block test_bb, rtx cond,
			      unsigned int *cost, bool *simple_p)
{
  if (!test_bb)
    return false;

  rtx_insn *last_insn = last_active_insn (test_bb, FALSE);
  rtx last_set = NULL_RTX;

  rtx cc = cc_in_cond (cond);

  if (!insn_valid_noce_process_p (last_insn, cc))
    return false;
  last_set = single_set (last_insn);

  rtx x = SET_DEST (last_set);
  rtx_insn *first_insn = first_active_insn (test_bb);
  rtx first_set = single_set (first_insn);

  if (!first_set)
    return false;

  /* We have a single simple set, that's okay.  */
  bool speed_p = optimize_bb_for_speed_p (test_bb);

  if (first_insn == last_insn)
    {
      *simple_p = noce_operand_ok (SET_DEST (first_set));
      *cost += insn_rtx_cost (first_set, speed_p);
      return *simple_p;
    }

  rtx_insn *prev_last_insn = PREV_INSN (last_insn);
  gcc_assert (prev_last_insn);

  /* For now, disallow setting x multiple times in test_bb.  */
  if (REG_P (x) && reg_set_between_p (x, first_insn, prev_last_insn))
    return false;

  bitmap test_bb_temps = BITMAP_ALLOC (&reg_obstack);

  /* The regs that are live out of test_bb.  */
  bitmap test_bb_live_out = df_get_live_out (test_bb);

  int potential_cost = insn_rtx_cost (last_set, speed_p);
  rtx_insn *insn;
  FOR_BB_INSNS (test_bb, insn)
    {
      if (insn != last_insn)
	{
	  if (!active_insn_p (insn))
	    continue;

	  if (!insn_valid_noce_process_p (insn, cc))
	    goto free_bitmap_and_fail;

	  rtx sset = single_set (insn);
	  gcc_assert (sset);

	  if (contains_mem_rtx_p (SET_SRC (sset))
	      || !REG_P (SET_DEST (sset))
	      || reg_overlap_mentioned_p (SET_DEST (sset), cond))
	    goto free_bitmap_and_fail;

	  potential_cost += insn_rtx_cost (sset, speed_p);
	  bitmap_set_bit (test_bb_temps, REGNO (SET_DEST (sset)));
	}
    }

  /* If any of the intermediate results in test_bb are live after test_bb
     then fail.  */
  if (bitmap_intersect_p (test_bb_live_out, test_bb_temps))
    goto free_bitmap_and_fail;

  BITMAP_FREE (test_bb_temps);
  *cost += potential_cost;
  *simple_p = false;
  return true;

 free_bitmap_and_fail:
  BITMAP_FREE (test_bb_temps);
  return false;
}

/* We have something like:

     if (x > y)
       { i = a; j = b; k = c; }

   Make it:

     tmp_i = (x > y) ? a : i;
     tmp_j = (x > y) ? b : j;
     tmp_k = (x > y) ? c : k;
     i = tmp_i;
     j = tmp_j;
     k = tmp_k;

   Subsequent passes are expected to clean up the extra moves.

   Look for special cases such as writes to one register which are
   read back in another SET, as might occur in a swap idiom or
   similar.

   These look like:

   if (x > y)
     i = a;
     j = i;

   Which we want to rewrite to:

     tmp_i = (x > y) ? a : i;
     tmp_j = (x > y) ? tmp_i : j;
     i = tmp_i;
     j = tmp_j;

   We can catch these when looking at (SET x y) by keeping a list of the
   registers we would have targeted before if-conversion and looking back
   through it for an overlap with Y.  If we find one, we rewire the
   conditional set to use the temporary we introduced earlier.

   IF_INFO contains the useful information about the block structure and
   jump instructions.  */

static int
noce_convert_multiple_sets (struct noce_if_info *if_info)
{
  basic_block test_bb = if_info->test_bb;
  basic_block then_bb = if_info->then_bb;
  basic_block join_bb = if_info->join_bb;
  rtx_insn *jump = if_info->jump;
  rtx_insn *cond_earliest;
  rtx_insn *insn;

  start_sequence ();

  /* Decompose the condition attached to the jump.  */
  rtx cond = noce_get_condition (jump, &cond_earliest, false);
  rtx x = XEXP (cond, 0);
  rtx y = XEXP (cond, 1);
  rtx_code cond_code = GET_CODE (cond);

  /* The true targets for a conditional move.  */
  auto_vec<rtx> targets;
  /* The temporaries introduced to allow us to not consider register
     overlap.  */
  auto_vec<rtx> temporaries;
  /* The insns we've emitted.  */
  auto_vec<rtx_insn *> unmodified_insns;
  int count = 0;

  FOR_BB_INSNS (then_bb, insn)
    {
      /* Skip over non-insns.  */
      if (!active_insn_p (insn))
	continue;

      rtx set = single_set (insn);
      gcc_checking_assert (set);

      rtx target = SET_DEST (set);
      rtx temp = gen_reg_rtx (GET_MODE (target));
      rtx new_val = SET_SRC (set);
      rtx old_val = target;

      /* If we were supposed to read from an earlier write in this block,
	 we've changed the register allocation.  Rewire the read.  While
	 we are looking, also try to catch a swap idiom.  */
      for (int i = count - 1; i >= 0; --i)
	if (reg_overlap_mentioned_p (new_val, targets[i]))
	  {
	    /* Catch a "swap" style idiom.  */
	    if (find_reg_note (insn, REG_DEAD, new_val) != NULL_RTX)
	      /* The write to targets[i] is only live until the read
		 here.  As the condition codes match, we can propagate
		 the set to here.  */
	      new_val = SET_SRC (single_set (unmodified_insns[i]));
	    else
	      new_val = temporaries[i];
	    break;
	  }

      /* If we had a non-canonical conditional jump (i.e. one where
	 the fallthrough is to the "else" case) we need to reverse
	 the conditional select.  */
      if (if_info->then_else_reversed)
	std::swap (old_val, new_val);


      /* We allow simple lowpart register subreg SET sources in
	 bb_ok_for_noce_convert_multiple_sets.  Be careful when processing
	 sequences like:
	 (set (reg:SI r1) (reg:SI r2))
	 (set (reg:HI r3) (subreg:HI (r1)))
	 For the second insn new_val or old_val (r1 in this example) will be
	 taken from the temporaries and have the wider mode which will not
	 match with the mode of the other source of the conditional move, so
	 we'll end up trying to emit r4:HI = cond ? (r1:SI) : (r3:HI).
	 Wrap the two cmove operands into subregs if appropriate to prevent
	 that.  */
      if (GET_MODE (new_val) != GET_MODE (temp))
	{
	  machine_mode src_mode = GET_MODE (new_val);
	  machine_mode dst_mode = GET_MODE (temp);
	  if (GET_MODE_SIZE (src_mode) <= GET_MODE_SIZE (dst_mode))
	    {
	      end_sequence ();
	      return FALSE;
	    }
	  new_val = lowpart_subreg (dst_mode, new_val, src_mode);
	}
      if (GET_MODE (old_val) != GET_MODE (temp))
	{
	  machine_mode src_mode = GET_MODE (old_val);
	  machine_mode dst_mode = GET_MODE (temp);
	  if (GET_MODE_SIZE (src_mode) <= GET_MODE_SIZE (dst_mode))
	    {
	      end_sequence ();
	      return FALSE;
	    }
	  old_val = lowpart_subreg (dst_mode, old_val, src_mode);
	}

      /* Actually emit the conditional move.  */
      rtx temp_dest = noce_emit_cmove (if_info, temp, cond_code,
				       x, y, new_val, old_val);

      /* If we failed to expand the conditional move, drop out and don't
	 try to continue.  */
      if (temp_dest == NULL_RTX)
	{
	  end_sequence ();
	  return FALSE;
	}

      /* Bookkeeping.  */
      count++;
      targets.safe_push (target);
      temporaries.safe_push (temp_dest);
      unmodified_insns.safe_push (insn);
    }

  /* We must have seen some sort of insn to insert, otherwise we were
     given an empty BB to convert, and we can't handle that.  */
  gcc_assert (!unmodified_insns.is_empty ());

  /* Now fixup the assignments.  */
  for (int i = 0; i < count; i++)
    noce_emit_move_insn (targets[i], temporaries[i]);

  /* Actually emit the sequence if it isn't too expensive.  */
  rtx_insn *seq = get_insns ();

  if (!noce_conversion_profitable_p (seq, if_info))
    {
      end_sequence ();
      return FALSE;
    }

  for (insn = seq; insn; insn = NEXT_INSN (insn))
    set_used_flags (insn);

  /* Mark all our temporaries and targets as used.  */
  for (int i = 0; i < count; i++)
    {
      set_used_flags (temporaries[i]);
      set_used_flags (targets[i]);
    }

  set_used_flags (cond);
  set_used_flags (x);
  set_used_flags (y);

  unshare_all_rtl_in_chain (seq);
  end_sequence ();

  if (!seq)
    return FALSE;

  for (insn = seq; insn; insn = NEXT_INSN (insn))
    if (JUMP_P (insn)
	|| recog_memoized (insn) == -1)
      return FALSE;

  emit_insn_before_setloc (seq, if_info->jump,
			   INSN_LOCATION (unmodified_insns.last ()));

  /* Clean up THEN_BB and the edges in and out of it.  */
  remove_edge (find_edge (test_bb, join_bb));
  remove_edge (find_edge (then_bb, join_bb));
  redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
  delete_basic_block (then_bb);
  num_true_changes++;

  /* Maybe merge blocks now the jump is simple enough.  */
  if (can_merge_blocks_p (test_bb, join_bb))
    {
      merge_blocks (test_bb, join_bb);
      num_true_changes++;
    }

  num_updated_if_blocks++;
  if_info->transform_name = "noce_convert_multiple_sets";
  return TRUE;
}

/* Return true iff basic block TEST_BB is comprised of only
   (SET (REG) (REG)) insns suitable for conversion to a series
   of conditional moves.  Also check that we have more than one set
   (other routines can handle a single set better than we would), and
   fewer than PARAM_MAX_RTL_IF_CONVERSION_INSNS sets.  */

static bool
bb_ok_for_noce_convert_multiple_sets (basic_block test_bb)
{
  rtx_insn *insn;
  unsigned count = 0;
  unsigned param = PARAM_VALUE (PARAM_MAX_RTL_IF_CONVERSION_INSNS);

  FOR_BB_INSNS (test_bb, insn)
    {
      /* Skip over notes etc.  */
      if (!active_insn_p (insn))
	continue;

      /* We only handle SET insns.  */
      rtx set = single_set (insn);
      if (set == NULL_RTX)
	return false;

      rtx dest = SET_DEST (set);
      rtx src = SET_SRC (set);

      /* We can possibly relax this, but for now only handle REG to REG
	 (including subreg) moves.  This avoids any issues that might come
	 from introducing loads/stores that might violate data-race-freedom
	 guarantees.  */
      if (!REG_P (dest))
	return false;

      if (!(REG_P (src)
	   || (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
	       && subreg_lowpart_p (src))))
	return false;

      /* Destination must be appropriate for a conditional write.  */
      if (!noce_operand_ok (dest))
	return false;

      /* We must be able to conditionally move in this mode.  */
      if (!can_conditionally_move_p (GET_MODE (dest)))
	return false;

      count++;
    }

  /* If we would only put out one conditional move, the other strategies
     this pass tries are better optimized and will be more appropriate.
     Some targets want to strictly limit the number of conditional moves
     that are emitted, they set this through PARAM, we need to respect
     that.  */
  return count > 1 && count <= param;
}

/* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
   it without using conditional execution.  Return TRUE if we were successful
   at converting the block.  */

static int
noce_process_if_block (struct noce_if_info *if_info)
{
  basic_block test_bb = if_info->test_bb;	/* test block */
  basic_block then_bb = if_info->then_bb;	/* THEN */
  basic_block else_bb = if_info->else_bb;	/* ELSE or NULL */
  basic_block join_bb = if_info->join_bb;	/* JOIN */
  rtx_insn *jump = if_info->jump;
  rtx cond = if_info->cond;
  rtx_insn *insn_a, *insn_b;
  rtx set_a, set_b;
  rtx orig_x, x, a, b;

  /* We're looking for patterns of the form

     (1) if (...) x = a; else x = b;
     (2) x = b; if (...) x = a;
     (3) if (...) x = a;   // as if with an initial x = x.
     (4) if (...) { x = a; y = b; z = c; }  // Like 3, for multiple SETS.
     The later patterns require jumps to be more expensive.
     For the if (...) x = a; else x = b; case we allow multiple insns
     inside the then and else blocks as long as their only effect is
     to calculate a value for x.
     ??? For future expansion, further expand the "multiple X" rules.  */

  /* First look for multiple SETS.  */
  if (!else_bb
      && HAVE_conditional_move
      && !HAVE_cc0
      && bb_ok_for_noce_convert_multiple_sets (then_bb))
    {
      if (noce_convert_multiple_sets (if_info))
	{
	  if (dump_file && if_info->transform_name)
	    fprintf (dump_file, "if-conversion succeeded through %s\n",
		     if_info->transform_name);
	  return TRUE;
	}
    }

  if (! bb_valid_for_noce_process_p (then_bb, cond, &if_info->original_cost,
				    &if_info->then_simple))
    return false;

  if (else_bb
      && ! bb_valid_for_noce_process_p (else_bb, cond, &if_info->original_cost,
				      &if_info->else_simple))
    return false;

  insn_a = last_active_insn (then_bb, FALSE);
  set_a = single_set (insn_a);
  gcc_assert (set_a);

  x = SET_DEST (set_a);
  a = SET_SRC (set_a);

  /* Look for the other potential set.  Make sure we've got equivalent
     destinations.  */
  /* ??? This is overconservative.  Storing to two different mems is
     as easy as conditionally computing the address.  Storing to a
     single mem merely requires a scratch memory to use as one of the
     destination addresses; often the memory immediately below the
     stack pointer is available for this.  */
  set_b = NULL_RTX;
  if (else_bb)
    {
      insn_b = last_active_insn (else_bb, FALSE);
      set_b = single_set (insn_b);
      gcc_assert (set_b);

      if (!rtx_interchangeable_p (x, SET_DEST (set_b)))
	return FALSE;
    }
  else
    {
      insn_b = prev_nonnote_nondebug_insn (if_info->cond_earliest);
      /* We're going to be moving the evaluation of B down from above
	 COND_EARLIEST to JUMP.  Make sure the relevant data is still
	 intact.  */
      if (! insn_b
	  || BLOCK_FOR_INSN (insn_b) != BLOCK_FOR_INSN (if_info->cond_earliest)
	  || !NONJUMP_INSN_P (insn_b)
	  || (set_b = single_set (insn_b)) == NULL_RTX
	  || ! rtx_interchangeable_p (x, SET_DEST (set_b))
	  || ! noce_operand_ok (SET_SRC (set_b))
	  || reg_overlap_mentioned_p (x, SET_SRC (set_b))
	  || modified_between_p (SET_SRC (set_b), insn_b, jump)
	  /* Avoid extending the lifetime of hard registers on small
	     register class machines.  */
	  || (REG_P (SET_SRC (set_b))
	      && HARD_REGISTER_P (SET_SRC (set_b))
	      && targetm.small_register_classes_for_mode_p
		   (GET_MODE (SET_SRC (set_b))))
	  /* Likewise with X.  In particular this can happen when
	     noce_get_condition looks farther back in the instruction
	     stream than one might expect.  */
	  || reg_overlap_mentioned_p (x, cond)
	  || reg_overlap_mentioned_p (x, a)
	  || modified_between_p (x, insn_b, jump))
	{
	  insn_b = NULL;
	  set_b = NULL_RTX;
	}
    }

  /* If x has side effects then only the if-then-else form is safe to
     convert.  But even in that case we would need to restore any notes
     (such as REG_INC) at then end.  That can be tricky if
     noce_emit_move_insn expands to more than one insn, so disable the
     optimization entirely for now if there are side effects.  */
  if (side_effects_p (x))
    return FALSE;

  b = (set_b ? SET_SRC (set_b) : x);

  /* Only operate on register destinations, and even then avoid extending
     the lifetime of hard registers on small register class machines.  */
  orig_x = x;
  if_info->orig_x = orig_x;
  if (!REG_P (x)
      || (HARD_REGISTER_P (x)
	  && targetm.small_register_classes_for_mode_p (GET_MODE (x))))
    {
      if (GET_MODE (x) == BLKmode)
	return FALSE;

      if (GET_CODE (x) == ZERO_EXTRACT
	  && (!CONST_INT_P (XEXP (x, 1))
	      || !CONST_INT_P (XEXP (x, 2))))
	return FALSE;

      x = gen_reg_rtx (GET_MODE (GET_CODE (x) == STRICT_LOW_PART
				 ? XEXP (x, 0) : x));
    }

  /* Don't operate on sources that may trap or are volatile.  */
  if (! noce_operand_ok (a) || ! noce_operand_ok (b))
    return FALSE;

 retry:
  /* Set up the info block for our subroutines.  */
  if_info->insn_a = insn_a;
  if_info->insn_b = insn_b;
  if_info->x = x;
  if_info->a = a;
  if_info->b = b;

  /* Try optimizations in some approximation of a useful order.  */
  /* ??? Should first look to see if X is live incoming at all.  If it
     isn't, we don't need anything but an unconditional set.  */

  /* Look and see if A and B are really the same.  Avoid creating silly
     cmove constructs that no one will fix up later.  */
  if (noce_simple_bbs (if_info)
      && rtx_interchangeable_p (a, b))
    {
      /* If we have an INSN_B, we don't have to create any new rtl.  Just
	 move the instruction that we already have.  If we don't have an
	 INSN_B, that means that A == X, and we've got a noop move.  In
	 that case don't do anything and let the code below delete INSN_A.  */
      if (insn_b && else_bb)
	{
	  rtx note;

	  if (else_bb && insn_b == BB_END (else_bb))
	    BB_END (else_bb) = PREV_INSN (insn_b);
	  reorder_insns (insn_b, insn_b, PREV_INSN (jump));

	  /* If there was a REG_EQUAL note, delete it since it may have been
	     true due to this insn being after a jump.  */
	  if ((note = find_reg_note (insn_b, REG_EQUAL, NULL_RTX)) != 0)
	    remove_note (insn_b, note);

	  insn_b = NULL;
	}
      /* If we have "x = b; if (...) x = a;", and x has side-effects, then
	 x must be executed twice.  */
      else if (insn_b && side_effects_p (orig_x))
	return FALSE;

      x = orig_x;
      goto success;
    }

  if (!set_b && MEM_P (orig_x))
    /* We want to avoid store speculation to avoid cases like
	 if (pthread_mutex_trylock(mutex))
	   ++global_variable;
       Rather than go to much effort here, we rely on the SSA optimizers,
       which do a good enough job these days.  */
    return FALSE;

  if (noce_try_move (if_info))
    goto success;
  if (noce_try_ifelse_collapse (if_info))
    goto success;
  if (noce_try_store_flag (if_info))
    goto success;
  if (noce_try_bitop (if_info))
    goto success;
  if (noce_try_minmax (if_info))
    goto success;
  if (noce_try_abs (if_info))
    goto success;
  if (noce_try_inverse_constants (if_info))
    goto success;
  if (!targetm.have_conditional_execution ()
      && noce_try_store_flag_constants (if_info))
    goto success;
  if (HAVE_conditional_move
      && noce_try_cmove (if_info))
    goto success;
  if (! targetm.have_conditional_execution ())
    {
      if (noce_try_addcc (if_info))
	goto success;
      if (noce_try_store_flag_mask (if_info))
	goto success;
      if (HAVE_conditional_move
	  && noce_try_cmove_arith (if_info))
	goto success;
      if (noce_try_sign_mask (if_info))
	goto success;
    }

  if (!else_bb && set_b)
    {
      insn_b = NULL;
      set_b = NULL_RTX;
      b = orig_x;
      goto retry;
    }

  return FALSE;

 success:
  if (dump_file && if_info->transform_name)
    fprintf (dump_file, "if-conversion succeeded through %s\n",
	     if_info->transform_name);

  /* If we used a temporary, fix it up now.  */
  if (orig_x != x)
    {
      rtx_insn *seq;

      start_sequence ();
      noce_emit_move_insn (orig_x, x);
      seq = get_insns ();
      set_used_flags (orig_x);
      unshare_all_rtl_in_chain (seq);
      end_sequence ();

      emit_insn_before_setloc (seq, BB_END (test_bb), INSN_LOCATION (insn_a));
    }

  /* The original THEN and ELSE blocks may now be removed.  The test block
     must now jump to the join block.  If the test block and the join block
     can be merged, do so.  */
  if (else_bb)
    {
      delete_basic_block (else_bb);
      num_true_changes++;
    }
  else
    remove_edge (find_edge (test_bb, join_bb));

  remove_edge (find_edge (then_bb, join_bb));
  redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
  delete_basic_block (then_bb);
  num_true_changes++;

  if (can_merge_blocks_p (test_bb, join_bb))
    {
      merge_blocks (test_bb, join_bb);
      num_true_changes++;
    }

  num_updated_if_blocks++;
  return TRUE;
}

/* Check whether a block is suitable for conditional move conversion.
   Every insn must be a simple set of a register to a constant or a
   register.  For each assignment, store the value in the pointer map
   VALS, keyed indexed by register pointer, then store the register
   pointer in REGS.  COND is the condition we will test.  */

static int
check_cond_move_block (basic_block bb,
		       hash_map<rtx, rtx> *vals,
		       vec<rtx> *regs,
		       rtx cond)
{
  rtx_insn *insn;
  rtx cc = cc_in_cond (cond);

   /* We can only handle simple jumps at the end of the basic block.
      It is almost impossible to update the CFG otherwise.  */
  insn = BB_END (bb);
  if (JUMP_P (insn) && !onlyjump_p (insn))
    return FALSE;

  FOR_BB_INSNS (bb, insn)
    {
      rtx set, dest, src;

      if (!NONDEBUG_INSN_P (insn) || JUMP_P (insn))
	continue;
      set = single_set (insn);
      if (!set)
	return FALSE;

      dest = SET_DEST (set);
      src = SET_SRC (set);
      if (!REG_P (dest)
	  || (HARD_REGISTER_P (dest)
	      && targetm.small_register_classes_for_mode_p (GET_MODE (dest))))
	return FALSE;

      if (!CONSTANT_P (src) && !register_operand (src, VOIDmode))
	return FALSE;

      if (side_effects_p (src) || side_effects_p (dest))
	return FALSE;

      if (may_trap_p (src) || may_trap_p (dest))
	return FALSE;

      /* Don't try to handle this if the source register was
	 modified earlier in the block.  */
      if ((REG_P (src)
	   && vals->get (src))
	  || (GET_CODE (src) == SUBREG && REG_P (SUBREG_REG (src))
	      && vals->get (SUBREG_REG (src))))
	return FALSE;

      /* Don't try to handle this if the destination register was
	 modified earlier in the block.  */
      if (vals->get (dest))
	return FALSE;

      /* Don't try to handle this if the condition uses the
	 destination register.  */
      if (reg_overlap_mentioned_p (dest, cond))
	return FALSE;

      /* Don't try to handle this if the source register is modified
	 later in the block.  */
      if (!CONSTANT_P (src)
	  && modified_between_p (src, insn, NEXT_INSN (BB_END (bb))))
	return FALSE;

      /* Skip it if the instruction to be moved might clobber CC.  */
      if (cc && set_of (cc, insn))
	return FALSE;

      vals->put (dest, src);

      regs->safe_push (dest);
    }

  return TRUE;
}

/* Given a basic block BB suitable for conditional move conversion,
   a condition COND, and pointer maps THEN_VALS and ELSE_VALS containing
   the register values depending on COND, emit the insns in the block as
   conditional moves.  If ELSE_BLOCK is true, THEN_BB was already
   processed.  The caller has started a sequence for the conversion.
   Return true if successful, false if something goes wrong.  */

static bool
cond_move_convert_if_block (struct noce_if_info *if_infop,
			    basic_block bb, rtx cond,
			    hash_map<rtx, rtx> *then_vals,
			    hash_map<rtx, rtx> *else_vals,
			    bool else_block_p)
{
  enum rtx_code code;
  rtx_insn *insn;
  rtx cond_arg0, cond_arg1;

  code = GET_CODE (cond);
  cond_arg0 = XEXP (cond, 0);
  cond_arg1 = XEXP (cond, 1);

  FOR_BB_INSNS (bb, insn)
    {
      rtx set, target, dest, t, e;

      /* ??? Maybe emit conditional debug insn?  */
      if (!NONDEBUG_INSN_P (insn) || JUMP_P (insn))
	continue;
      set = single_set (insn);
      gcc_assert (set && REG_P (SET_DEST (set)));

      dest = SET_DEST (set);

      rtx *then_slot = then_vals->get (dest);
      rtx *else_slot = else_vals->get (dest);
      t = then_slot ? *then_slot : NULL_RTX;
      e = else_slot ? *else_slot : NULL_RTX;

      if (else_block_p)
	{
	  /* If this register was set in the then block, we already
	     handled this case there.  */
	  if (t)
	    continue;
	  t = dest;
	  gcc_assert (e);
	}
      else
	{
	  gcc_assert (t);
	  if (!e)
	    e = dest;
	}

      target = noce_emit_cmove (if_infop, dest, code, cond_arg0, cond_arg1,
				t, e);
      if (!target)
	return false;

      if (target != dest)
	noce_emit_move_insn (dest, target);
    }

  return true;
}

/* Given a simple IF-THEN-JOIN or IF-THEN-ELSE-JOIN block, attempt to convert
   it using only conditional moves.  Return TRUE if we were successful at
   converting the block.  */

static int
cond_move_process_if_block (struct noce_if_info *if_info)
{
  basic_block test_bb = if_info->test_bb;
  basic_block then_bb = if_info->then_bb;
  basic_block else_bb = if_info->else_bb;
  basic_block join_bb = if_info->join_bb;
  rtx_insn *jump = if_info->jump;
  rtx cond = if_info->cond;
  rtx_insn *seq, *loc_insn;
  rtx reg;
  int c;
  vec<rtx> then_regs = vNULL;
  vec<rtx> else_regs = vNULL;
  unsigned int i;
  int success_p = FALSE;
  int limit = PARAM_VALUE (PARAM_MAX_RTL_IF_CONVERSION_INSNS);

  /* Build a mapping for each block to the value used for each
     register.  */
  hash_map<rtx, rtx> then_vals;
  hash_map<rtx, rtx> else_vals;

  /* Make sure the blocks are suitable.  */
  if (!check_cond_move_block (then_bb, &then_vals, &then_regs, cond)
      || (else_bb
	  && !check_cond_move_block (else_bb, &else_vals, &else_regs, cond)))
    goto done;

  /* Make sure the blocks can be used together.  If the same register
     is set in both blocks, and is not set to a constant in both
     cases, then both blocks must set it to the same register.  We
     have already verified that if it is set to a register, that the
     source register does not change after the assignment.  Also count
     the number of registers set in only one of the blocks.  */
  c = 0;
  FOR_EACH_VEC_ELT (then_regs, i, reg)
    {
      rtx *then_slot = then_vals.get (reg);
      rtx *else_slot = else_vals.get (reg);

      gcc_checking_assert (then_slot);
      if (!else_slot)
	++c;
      else
	{
	  rtx then_val = *then_slot;
	  rtx else_val = *else_slot;
	  if (!CONSTANT_P (then_val) && !CONSTANT_P (else_val)
	      && !rtx_equal_p (then_val, else_val))
	    goto done;
	}
    }

  /* Finish off c for MAX_CONDITIONAL_EXECUTE.  */
  FOR_EACH_VEC_ELT (else_regs, i, reg)
    {
      gcc_checking_assert (else_vals.get (reg));
      if (!then_vals.get (reg))
	++c;
    }

  /* Make sure it is reasonable to convert this block.  What matters
     is the number of assignments currently made in only one of the
     branches, since if we convert we are going to always execute
     them.  */
  if (c > MAX_CONDITIONAL_EXECUTE
      || c > limit)
    goto done;

  /* Try to emit the conditional moves.  First do the then block,
     then do anything left in the else blocks.  */
  start_sequence ();
  if (!cond_move_convert_if_block (if_info, then_bb, cond,
				   &then_vals, &else_vals, false)
      || (else_bb
	  && !cond_move_convert_if_block (if_info, else_bb, cond,
					  &then_vals, &else_vals, true)))
    {
      end_sequence ();
      goto done;
    }
  seq = end_ifcvt_sequence (if_info);
  if (!seq)
    goto done;

  loc_insn = first_active_insn (then_bb);
  if (!loc_insn)
    {
      loc_insn = first_active_insn (else_bb);
      gcc_assert (loc_insn);
    }
  emit_insn_before_setloc (seq, jump, INSN_LOCATION (loc_insn));

  if (else_bb)
    {
      delete_basic_block (else_bb);
      num_true_changes++;
    }
  else
    remove_edge (find_edge (test_bb, join_bb));

  remove_edge (find_edge (then_bb, join_bb));
  redirect_edge_and_branch_force (single_succ_edge (test_bb), join_bb);
  delete_basic_block (then_bb);
  num_true_changes++;

  if (can_merge_blocks_p (test_bb, join_bb))
    {
      merge_blocks (test_bb, join_bb);
      num_true_changes++;
    }

  num_updated_if_blocks++;
  success_p = TRUE;

done:
  then_regs.release ();
  else_regs.release ();
  return success_p;
}


/* Determine if a given basic block heads a simple IF-THEN-JOIN or an
   IF-THEN-ELSE-JOIN block.

   If so, we'll try to convert the insns to not require the branch,
   using only transformations that do not require conditional execution.

   Return TRUE if we were successful at converting the block.  */

static int
noce_find_if_block (basic_block test_bb, edge then_edge, edge else_edge,
		    int pass)
{
  basic_block then_bb, else_bb, join_bb;
  bool then_else_reversed = false;
  rtx_insn *jump;
  rtx cond;
  rtx_insn *cond_earliest;
  struct noce_if_info if_info;
  bool speed_p = optimize_bb_for_speed_p (test_bb);

  /* We only ever should get here before reload.  */
  gcc_assert (!reload_completed);

  /* Recognize an IF-THEN-ELSE-JOIN block.  */
  if (single_pred_p (then_edge->dest)
      && single_succ_p (then_edge->dest)
      && single_pred_p (else_edge->dest)
      && single_succ_p (else_edge->dest)
      && single_succ (then_edge->dest) == single_succ (else_edge->dest))
    {
      then_bb = then_edge->dest;
      else_bb = else_edge->dest;
      join_bb = single_succ (then_bb);
    }
  /* Recognize an IF-THEN-JOIN block.  */
  else if (single_pred_p (then_edge->dest)
	   && single_succ_p (then_edge->dest)
	   && single_succ (then_edge->dest) == else_edge->dest)
    {
      then_bb = then_edge->dest;
      else_bb = NULL_BLOCK;
      join_bb = else_edge->dest;
    }
  /* Recognize an IF-ELSE-JOIN block.  We can have those because the order
     of basic blocks in cfglayout mode does not matter, so the fallthrough
     edge can go to any basic block (and not just to bb->next_bb, like in
     cfgrtl mode).  */
  else if (single_pred_p (else_edge->dest)
	   && single_succ_p (else_edge->dest)
	   && single_succ (else_edge->dest) == then_edge->dest)
    {
      /* The noce transformations do not apply to IF-ELSE-JOIN blocks.
	 To make this work, we have to invert the THEN and ELSE blocks
	 and reverse the jump condition.  */
      then_bb = else_edge->dest;
      else_bb = NULL_BLOCK;
      join_bb = single_succ (then_bb);
      then_else_reversed = true;
    }
  else
    /* Not a form we can handle.  */
    return FALSE;

  /* The edges of the THEN and ELSE blocks cannot have complex edges.  */
  if (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
    return FALSE;
  if (else_bb
      && single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
    return FALSE;

  num_possible_if_blocks++;

  if (dump_file)
    {
      fprintf (dump_file,
	       "\nIF-THEN%s-JOIN block found, pass %d, test %d, then %d",
	       (else_bb) ? "-ELSE" : "",
	       pass, test_bb->index, then_bb->index);

      if (else_bb)
	fprintf (dump_file, ", else %d", else_bb->index);

      fprintf (dump_file, ", join %d\n", join_bb->index);
    }

  /* If the conditional jump is more than just a conditional
     jump, then we can not do if-conversion on this block.  */
  jump = BB_END (test_bb);
  if (! onlyjump_p (jump))
    return FALSE;

  /* If this is not a standard conditional jump, we can't parse it.  */
  cond = noce_get_condition (jump, &cond_earliest, then_else_reversed);
  if (!cond)
    return FALSE;

  /* We must be comparing objects whose modes imply the size.  */
  if (GET_MODE (XEXP (cond, 0)) == BLKmode)
    return FALSE;

  /* Initialize an IF_INFO struct to pass around.  */
  memset (&if_info, 0, sizeof if_info);
  if_info.test_bb = test_bb;
  if_info.then_bb = then_bb;
  if_info.else_bb = else_bb;
  if_info.join_bb = join_bb;
  if_info.cond = cond;
  if_info.cond_earliest = cond_earliest;
  if_info.jump = jump;
  if_info.then_else_reversed = then_else_reversed;
  if_info.speed_p = speed_p;
  if_info.max_seq_cost
    = targetm.max_noce_ifcvt_seq_cost (then_edge);
  /* We'll add in the cost of THEN_BB and ELSE_BB later, when we check
     that they are valid to transform.  We can't easily get back to the insn
     for COND (and it may not exist if we had to canonicalize to get COND),
     and jump_insns are always given a cost of 1 by seq_cost, so treat
     both instructions as having cost COSTS_N_INSNS (1).  */
  if_info.original_cost = COSTS_N_INSNS (2);


  /* Do the real work.  */

  if (noce_process_if_block (&if_info))
    return TRUE;

  if (HAVE_conditional_move
      && cond_move_process_if_block (&if_info))
    return TRUE;

  return FALSE;
}


/* Merge the blocks and mark for local life update.  */

static void
merge_if_block (struct ce_if_block * ce_info)
{
  basic_block test_bb = ce_info->test_bb;	/* last test block */
  basic_block then_bb = ce_info->then_bb;	/* THEN */
  basic_block else_bb = ce_info->else_bb;	/* ELSE or NULL */
  basic_block join_bb = ce_info->join_bb;	/* join block */
  basic_block combo_bb;

  /* All block merging is done into the lower block numbers.  */

  combo_bb = test_bb;
  df_set_bb_dirty (test_bb);

  /* Merge any basic blocks to handle && and || subtests.  Each of
     the blocks are on the fallthru path from the predecessor block.  */
  if (ce_info->num_multiple_test_blocks > 0)
    {
      basic_block bb = test_bb;
      basic_block last_test_bb = ce_info->last_test_bb;
      basic_block fallthru = block_fallthru (bb);

      do
	{
	  bb = fallthru;
	  fallthru = block_fallthru (bb);
	  merge_blocks (combo_bb, bb);
	  num_true_changes++;
	}
      while (bb != last_test_bb);
    }

  /* Merge TEST block into THEN block.  Normally the THEN block won't have a
     label, but it might if there were || tests.  That label's count should be
     zero, and it normally should be removed.  */

  if (then_bb)
    {
      /* If THEN_BB has no successors, then there's a BARRIER after it.
	 If COMBO_BB has more than one successor (THEN_BB), then that BARRIER
	 is no longer needed, and in fact it is incorrect to leave it in
	 the insn stream.  */
      if (EDGE_COUNT (then_bb->succs) == 0
	  && EDGE_COUNT (combo_bb->succs) > 1)
	{
	  rtx_insn *end = NEXT_INSN (BB_END (then_bb));
	  while (end && NOTE_P (end) && !NOTE_INSN_BASIC_BLOCK_P (end))
	    end = NEXT_INSN (end);

	  if (end && BARRIER_P (end))
	    delete_insn (end);
	}
      merge_blocks (combo_bb, then_bb);
      num_true_changes++;
    }

  /* The ELSE block, if it existed, had a label.  That label count
     will almost always be zero, but odd things can happen when labels
     get their addresses taken.  */
  if (else_bb)
    {
      /* If ELSE_BB has no successors, then there's a BARRIER after it.
	 If COMBO_BB has more than one successor (ELSE_BB), then that BARRIER
	 is no longer needed, and in fact it is incorrect to leave it in
	 the insn stream.  */
      if (EDGE_COUNT (else_bb->succs) == 0
	  && EDGE_COUNT (combo_bb->succs) > 1)
	{
	  rtx_insn *end = NEXT_INSN (BB_END (else_bb));
	  while (end && NOTE_P (end) && !NOTE_INSN_BASIC_BLOCK_P (end))
	    end = NEXT_INSN (end);

	  if (end && BARRIER_P (end))
	    delete_insn (end);
	}
      merge_blocks (combo_bb, else_bb);
      num_true_changes++;
    }

  /* If there was no join block reported, that means it was not adjacent
     to the others, and so we cannot merge them.  */

  if (! join_bb)
    {
      rtx_insn *last = BB_END (combo_bb);

      /* The outgoing edge for the current COMBO block should already
	 be correct.  Verify this.  */
      if (EDGE_COUNT (combo_bb->succs) == 0)
	gcc_assert (find_reg_note (last, REG_NORETURN, NULL)
		    || (NONJUMP_INSN_P (last)
			&& GET_CODE (PATTERN (last)) == TRAP_IF
			&& (TRAP_CONDITION (PATTERN (last))
			    == const_true_rtx)));

      else
      /* There should still be something at the end of the THEN or ELSE
         blocks taking us to our final destination.  */
	gcc_assert (JUMP_P (last)
		    || (EDGE_SUCC (combo_bb, 0)->dest
			== EXIT_BLOCK_PTR_FOR_FN (cfun)
			&& CALL_P (last)
			&& SIBLING_CALL_P (last))
		    || ((EDGE_SUCC (combo_bb, 0)->flags & EDGE_EH)
			&& can_throw_internal (last)));
    }

  /* The JOIN block may have had quite a number of other predecessors too.
     Since we've already merged the TEST, THEN and ELSE blocks, we should
     have only one remaining edge from our if-then-else diamond.  If there
     is more than one remaining edge, it must come from elsewhere.  There
     may be zero incoming edges if the THEN block didn't actually join
     back up (as with a call to a non-return function).  */
  else if (EDGE_COUNT (join_bb->preds) < 2
	   && join_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      /* We can merge the JOIN cleanly and update the dataflow try
	 again on this pass.*/
      merge_blocks (combo_bb, join_bb);
      num_true_changes++;
    }
  else
    {
      /* We cannot merge the JOIN.  */

      /* The outgoing edge for the current COMBO block should already
	 be correct.  Verify this.  */
      gcc_assert (single_succ_p (combo_bb)
		  && single_succ (combo_bb) == join_bb);

      /* Remove the jump and cruft from the end of the COMBO block.  */
      if (join_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
	tidy_fallthru_edge (single_succ_edge (combo_bb));
    }

  num_updated_if_blocks++;
}

/* Find a block ending in a simple IF condition and try to transform it
   in some way.  When converting a multi-block condition, put the new code
   in the first such block and delete the rest.  Return a pointer to this
   first block if some transformation was done.  Return NULL otherwise.  */

static basic_block
find_if_header (basic_block test_bb, int pass)
{
  ce_if_block ce_info;
  edge then_edge;
  edge else_edge;

  /* The kind of block we're looking for has exactly two successors.  */
  if (EDGE_COUNT (test_bb->succs) != 2)
    return NULL;

  then_edge = EDGE_SUCC (test_bb, 0);
  else_edge = EDGE_SUCC (test_bb, 1);

  if (df_get_bb_dirty (then_edge->dest))
    return NULL;
  if (df_get_bb_dirty (else_edge->dest))
    return NULL;

  /* Neither edge should be abnormal.  */
  if ((then_edge->flags & EDGE_COMPLEX)
      || (else_edge->flags & EDGE_COMPLEX))
    return NULL;

  /* Nor exit the loop.  */
  if ((then_edge->flags & EDGE_LOOP_EXIT)
      || (else_edge->flags & EDGE_LOOP_EXIT))
    return NULL;

  /* The THEN edge is canonically the one that falls through.  */
  if (then_edge->flags & EDGE_FALLTHRU)
    ;
  else if (else_edge->flags & EDGE_FALLTHRU)
    std::swap (then_edge, else_edge);
  else
    /* Otherwise this must be a multiway branch of some sort.  */
    return NULL;

  memset (&ce_info, 0, sizeof (ce_info));
  ce_info.test_bb = test_bb;
  ce_info.then_bb = then_edge->dest;
  ce_info.else_bb = else_edge->dest;
  ce_info.pass = pass;

#ifdef IFCVT_MACHDEP_INIT
  IFCVT_MACHDEP_INIT (&ce_info);
#endif

  if (!reload_completed
      && noce_find_if_block (test_bb, then_edge, else_edge, pass))
    goto success;

  if (reload_completed
      && targetm.have_conditional_execution ()
      && cond_exec_find_if_block (&ce_info))
    goto success;

  if (targetm.have_trap ()
      && optab_handler (ctrap_optab, word_mode) != CODE_FOR_nothing
      && find_cond_trap (test_bb, then_edge, else_edge))
    goto success;

  if (dom_info_state (CDI_POST_DOMINATORS) >= DOM_NO_FAST_QUERY
      && (reload_completed || !targetm.have_conditional_execution ()))
    {
      if (find_if_case_1 (test_bb, then_edge, else_edge))
	goto success;
      if (find_if_case_2 (test_bb, then_edge, else_edge))
	goto success;
    }

  return NULL;

 success:
  if (dump_file)
    fprintf (dump_file, "Conversion succeeded on pass %d.\n", pass);
  /* Set this so we continue looking.  */
  cond_exec_changed_p = TRUE;
  return ce_info.test_bb;
}

/* Return true if a block has two edges, one of which falls through to the next
   block, and the other jumps to a specific block, so that we can tell if the
   block is part of an && test or an || test.  Returns either -1 or the number
   of non-note, non-jump, non-USE/CLOBBER insns in the block.  */

static int
block_jumps_and_fallthru_p (basic_block cur_bb, basic_block target_bb)
{
  edge cur_edge;
  int fallthru_p = FALSE;
  int jump_p = FALSE;
  rtx_insn *insn;
  rtx_insn *end;
  int n_insns = 0;
  edge_iterator ei;

  if (!cur_bb || !target_bb)
    return -1;

  /* If no edges, obviously it doesn't jump or fallthru.  */
  if (EDGE_COUNT (cur_bb->succs) == 0)
    return FALSE;

  FOR_EACH_EDGE (cur_edge, ei, cur_bb->succs)
    {
      if (cur_edge->flags & EDGE_COMPLEX)
	/* Anything complex isn't what we want.  */
	return -1;

      else if (cur_edge->flags & EDGE_FALLTHRU)
	fallthru_p = TRUE;

      else if (cur_edge->dest == target_bb)
	jump_p = TRUE;

      else
	return -1;
    }

  if ((jump_p & fallthru_p) == 0)
    return -1;

  /* Don't allow calls in the block, since this is used to group && and ||
     together for conditional execution support.  ??? we should support
     conditional execution support across calls for IA-64 some day, but
     for now it makes the code simpler.  */
  end = BB_END (cur_bb);
  insn = BB_HEAD (cur_bb);

  while (insn != NULL_RTX)
    {
      if (CALL_P (insn))
	return -1;

      if (INSN_P (insn)
	  && !JUMP_P (insn)
	  && !DEBUG_INSN_P (insn)
	  && GET_CODE (PATTERN (insn)) != USE
	  && GET_CODE (PATTERN (insn)) != CLOBBER)
	n_insns++;

      if (insn == end)
	break;

      insn = NEXT_INSN (insn);
    }

  return n_insns;
}

/* Determine if a given basic block heads a simple IF-THEN or IF-THEN-ELSE
   block.  If so, we'll try to convert the insns to not require the branch.
   Return TRUE if we were successful at converting the block.  */

static int
cond_exec_find_if_block (struct ce_if_block * ce_info)
{
  basic_block test_bb = ce_info->test_bb;
  basic_block then_bb = ce_info->then_bb;
  basic_block else_bb = ce_info->else_bb;
  basic_block join_bb = NULL_BLOCK;
  edge cur_edge;
  basic_block next;
  edge_iterator ei;

  ce_info->last_test_bb = test_bb;

  /* We only ever should get here after reload,
     and if we have conditional execution.  */
  gcc_assert (reload_completed && targetm.have_conditional_execution ());

  /* Discover if any fall through predecessors of the current test basic block
     were && tests (which jump to the else block) or || tests (which jump to
     the then block).  */
  if (single_pred_p (test_bb)
      && single_pred_edge (test_bb)->flags == EDGE_FALLTHRU)
    {
      basic_block bb = single_pred (test_bb);
      basic_block target_bb;
      int max_insns = MAX_CONDITIONAL_EXECUTE;
      int n_insns;

      /* Determine if the preceding block is an && or || block.  */
      if ((n_insns = block_jumps_and_fallthru_p (bb, else_bb)) >= 0)
	{
	  ce_info->and_and_p = TRUE;
	  target_bb = else_bb;
	}
      else if ((n_insns = block_jumps_and_fallthru_p (bb, then_bb)) >= 0)
	{
	  ce_info->and_and_p = FALSE;
	  target_bb = then_bb;
	}
      else
	target_bb = NULL_BLOCK;

      if (target_bb && n_insns <= max_insns)
	{
	  int total_insns = 0;
	  int blocks = 0;

	  ce_info->last_test_bb = test_bb;

	  /* Found at least one && or || block, look for more.  */
	  do
	    {
	      ce_info->test_bb = test_bb = bb;
	      total_insns += n_insns;
	      blocks++;

	      if (!single_pred_p (bb))
		break;

	      bb = single_pred (bb);
	      n_insns = block_jumps_and_fallthru_p (bb, target_bb);
	    }
	  while (n_insns >= 0 && (total_insns + n_insns) <= max_insns);

	  ce_info->num_multiple_test_blocks = blocks;
	  ce_info->num_multiple_test_insns = total_insns;

	  if (ce_info->and_and_p)
	    ce_info->num_and_and_blocks = blocks;
	  else
	    ce_info->num_or_or_blocks = blocks;
	}
    }

  /* The THEN block of an IF-THEN combo must have exactly one predecessor,
     other than any || blocks which jump to the THEN block.  */
  if ((EDGE_COUNT (then_bb->preds) - ce_info->num_or_or_blocks) != 1)
    return FALSE;

  /* The edges of the THEN and ELSE blocks cannot have complex edges.  */
  FOR_EACH_EDGE (cur_edge, ei, then_bb->preds)
    {
      if (cur_edge->flags & EDGE_COMPLEX)
	return FALSE;
    }

  FOR_EACH_EDGE (cur_edge, ei, else_bb->preds)
    {
      if (cur_edge->flags & EDGE_COMPLEX)
	return FALSE;
    }

  /* The THEN block of an IF-THEN combo must have zero or one successors.  */
  if (EDGE_COUNT (then_bb->succs) > 0
      && (!single_succ_p (then_bb)
          || (single_succ_edge (then_bb)->flags & EDGE_COMPLEX)
	  || (epilogue_completed
	      && tablejump_p (BB_END (then_bb), NULL, NULL))))
    return FALSE;

  /* If the THEN block has no successors, conditional execution can still
     make a conditional call.  Don't do this unless the ELSE block has
     only one incoming edge -- the CFG manipulation is too ugly otherwise.
     Check for the last insn of the THEN block being an indirect jump, which
     is listed as not having any successors, but confuses the rest of the CE
     code processing.  ??? we should fix this in the future.  */
  if (EDGE_COUNT (then_bb->succs) == 0)
    {
      if (single_pred_p (else_bb) && else_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
	{
	  rtx_insn *last_insn = BB_END (then_bb);

	  while (last_insn
		 && NOTE_P (last_insn)
		 && last_insn != BB_HEAD (then_bb))
	    last_insn = PREV_INSN (last_insn);

	  if (last_insn
	      && JUMP_P (last_insn)
	      && ! simplejump_p (last_insn))
	    return FALSE;

	  join_bb = else_bb;
	  else_bb = NULL_BLOCK;
	}
      else
	return FALSE;
    }

  /* If the THEN block's successor is the other edge out of the TEST block,
     then we have an IF-THEN combo without an ELSE.  */
  else if (single_succ (then_bb) == else_bb)
    {
      join_bb = else_bb;
      else_bb = NULL_BLOCK;
    }

  /* If the THEN and ELSE block meet in a subsequent block, and the ELSE
     has exactly one predecessor and one successor, and the outgoing edge
     is not complex, then we have an IF-THEN-ELSE combo.  */
  else if (single_succ_p (else_bb)
	   && single_succ (then_bb) == single_succ (else_bb)
	   && single_pred_p (else_bb)
	   && !(single_succ_edge (else_bb)->flags & EDGE_COMPLEX)
	   && !(epilogue_completed
		&& tablejump_p (BB_END (else_bb), NULL, NULL)))
    join_bb = single_succ (else_bb);

  /* Otherwise it is not an IF-THEN or IF-THEN-ELSE combination.  */
  else
    return FALSE;

  num_possible_if_blocks++;

  if (dump_file)
    {
      fprintf (dump_file,
	       "\nIF-THEN%s block found, pass %d, start block %d "
	       "[insn %d], then %d [%d]",
	       (else_bb) ? "-ELSE" : "",
	       ce_info->pass,
	       test_bb->index,
	       BB_HEAD (test_bb) ? (int)INSN_UID (BB_HEAD (test_bb)) : -1,
	       then_bb->index,
	       BB_HEAD (then_bb) ? (int)INSN_UID (BB_HEAD (then_bb)) : -1);

      if (else_bb)
	fprintf (dump_file, ", else %d [%d]",
		 else_bb->index,
		 BB_HEAD (else_bb) ? (int)INSN_UID (BB_HEAD (else_bb)) : -1);

      fprintf (dump_file, ", join %d [%d]",
	       join_bb->index,
	       BB_HEAD (join_bb) ? (int)INSN_UID (BB_HEAD (join_bb)) : -1);

      if (ce_info->num_multiple_test_blocks > 0)
	fprintf (dump_file, ", %d %s block%s last test %d [%d]",
		 ce_info->num_multiple_test_blocks,
		 (ce_info->and_and_p) ? "&&" : "||",
		 (ce_info->num_multiple_test_blocks == 1) ? "" : "s",
		 ce_info->last_test_bb->index,
		 ((BB_HEAD (ce_info->last_test_bb))
		  ? (int)INSN_UID (BB_HEAD (ce_info->last_test_bb))
		  : -1));

      fputc ('\n', dump_file);
    }

  /* Make sure IF, THEN, and ELSE, blocks are adjacent.  Actually, we get the
     first condition for free, since we've already asserted that there's a
     fallthru edge from IF to THEN.  Likewise for the && and || blocks, since
     we checked the FALLTHRU flag, those are already adjacent to the last IF
     block.  */
  /* ??? As an enhancement, move the ELSE block.  Have to deal with
     BLOCK notes, if by no other means than backing out the merge if they
     exist.  Sticky enough I don't want to think about it now.  */
  next = then_bb;
  if (else_bb && (next = next->next_bb) != else_bb)
    return FALSE;
  if ((next = next->next_bb) != join_bb
      && join_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      if (else_bb)
	join_bb = NULL;
      else
	return FALSE;
    }

  /* Do the real work.  */

  ce_info->else_bb = else_bb;
  ce_info->join_bb = join_bb;

  /* If we have && and || tests, try to first handle combining the && and ||
     tests into the conditional code, and if that fails, go back and handle
     it without the && and ||, which at present handles the && case if there
     was no ELSE block.  */
  if (cond_exec_process_if_block (ce_info, TRUE))
    return TRUE;

  if (ce_info->num_multiple_test_blocks)
    {
      cancel_changes (0);

      if (cond_exec_process_if_block (ce_info, FALSE))
	return TRUE;
    }

  return FALSE;
}

/* Convert a branch over a trap, or a branch
   to a trap, into a conditional trap.  */

static int
find_cond_trap (basic_block test_bb, edge then_edge, edge else_edge)
{
  basic_block then_bb = then_edge->dest;
  basic_block else_bb = else_edge->dest;
  basic_block other_bb, trap_bb;
  rtx_insn *trap, *jump;
  rtx cond;
  rtx_insn *cond_earliest;
  enum rtx_code code;

  /* Locate the block with the trap instruction.  */
  /* ??? While we look for no successors, we really ought to allow
     EH successors.  Need to fix merge_if_block for that to work.  */
  if ((trap = block_has_only_trap (then_bb)) != NULL)
    trap_bb = then_bb, other_bb = else_bb;
  else if ((trap = block_has_only_trap (else_bb)) != NULL)
    trap_bb = else_bb, other_bb = then_bb;
  else
    return FALSE;

  if (dump_file)
    {
      fprintf (dump_file, "\nTRAP-IF block found, start %d, trap %d\n",
	       test_bb->index, trap_bb->index);
    }

  /* If this is not a standard conditional jump, we can't parse it.  */
  jump = BB_END (test_bb);
  cond = noce_get_condition (jump, &cond_earliest, false);
  if (! cond)
    return FALSE;

  /* If the conditional jump is more than just a conditional jump, then
     we can not do if-conversion on this block.  Give up for returnjump_p,
     changing a conditional return followed by unconditional trap for
     conditional trap followed by unconditional return is likely not
     beneficial and harder to handle.  */
  if (! onlyjump_p (jump) || returnjump_p (jump))
    return FALSE;

  /* We must be comparing objects whose modes imply the size.  */
  if (GET_MODE (XEXP (cond, 0)) == BLKmode)
    return FALSE;

  /* Reverse the comparison code, if necessary.  */
  code = GET_CODE (cond);
  if (then_bb == trap_bb)
    {
      code = reversed_comparison_code (cond, jump);
      if (code == UNKNOWN)
	return FALSE;
    }

  /* Attempt to generate the conditional trap.  */
  rtx_insn *seq = gen_cond_trap (code, copy_rtx (XEXP (cond, 0)),
				 copy_rtx (XEXP (cond, 1)),
				 TRAP_CODE (PATTERN (trap)));
  if (seq == NULL)
    return FALSE;

  /* Emit the new insns before cond_earliest.  */
  emit_insn_before_setloc (seq, cond_earliest, INSN_LOCATION (trap));

  /* Delete the trap block if possible.  */
  remove_edge (trap_bb == then_bb ? then_edge : else_edge);
  df_set_bb_dirty (test_bb);
  df_set_bb_dirty (then_bb);
  df_set_bb_dirty (else_bb);

  if (EDGE_COUNT (trap_bb->preds) == 0)
    {
      delete_basic_block (trap_bb);
      num_true_changes++;
    }

  /* Wire together the blocks again.  */
  if (current_ir_type () == IR_RTL_CFGLAYOUT)
    single_succ_edge (test_bb)->flags |= EDGE_FALLTHRU;
  else if (trap_bb == then_bb)
    {
      rtx lab = JUMP_LABEL (jump);
      rtx_insn *seq = targetm.gen_jump (lab);
      rtx_jump_insn *newjump = emit_jump_insn_after (seq, jump);
      LABEL_NUSES (lab) += 1;
      JUMP_LABEL (newjump) = lab;
      emit_barrier_after (newjump);
    }
  delete_insn (jump);

  if (can_merge_blocks_p (test_bb, other_bb))
    {
      merge_blocks (test_bb, other_bb);
      num_true_changes++;
    }

  num_updated_if_blocks++;
  return TRUE;
}

/* Subroutine of find_cond_trap: if BB contains only a trap insn,
   return it.  */

static rtx_insn *
block_has_only_trap (basic_block bb)
{
  rtx_insn *trap;

  /* We're not the exit block.  */
  if (bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
    return NULL;

  /* The block must have no successors.  */
  if (EDGE_COUNT (bb->succs) > 0)
    return NULL;

  /* The only instruction in the THEN block must be the trap.  */
  trap = first_active_insn (bb);
  if (! (trap == BB_END (bb)
	 && GET_CODE (PATTERN (trap)) == TRAP_IF
         && TRAP_CONDITION (PATTERN (trap)) == const_true_rtx))
    return NULL;

  return trap;
}

/* Look for IF-THEN-ELSE cases in which one of THEN or ELSE is
   transformable, but not necessarily the other.  There need be no
   JOIN block.

   Return TRUE if we were successful at converting the block.

   Cases we'd like to look at:

   (1)
	if (test) goto over; // x not live
	x = a;
	goto label;
	over:

   becomes

	x = a;
	if (! test) goto label;

   (2)
	if (test) goto E; // x not live
	x = big();
	goto L;
	E:
	x = b;
	goto M;

   becomes

	x = b;
	if (test) goto M;
	x = big();
	goto L;

   (3) // This one's really only interesting for targets that can do
       // multiway branching, e.g. IA-64 BBB bundles.  For other targets
       // it results in multiple branches on a cache line, which often
       // does not sit well with predictors.

	if (test1) goto E; // predicted not taken
	x = a;
	if (test2) goto F;
	...
	E:
	x = b;
	J:

   becomes

	x = a;
	if (test1) goto E;
	if (test2) goto F;

   Notes:

   (A) Don't do (2) if the branch is predicted against the block we're
   eliminating.  Do it anyway if we can eliminate a branch; this requires
   that the sole successor of the eliminated block postdominate the other
   side of the if.

   (B) With CE, on (3) we can steal from both sides of the if, creating

	if (test1) x = a;
	if (!test1) x = b;
	if (test1) goto J;
	if (test2) goto F;
	...
	J:

   Again, this is most useful if J postdominates.

   (C) CE substitutes for helpful life information.

   (D) These heuristics need a lot of work.  */

/* Tests for case 1 above.  */

static int
find_if_case_1 (basic_block test_bb, edge then_edge, edge else_edge)
{
  basic_block then_bb = then_edge->dest;
  basic_block else_bb = else_edge->dest;
  basic_block new_bb;
  int then_bb_index, then_prob;
  rtx else_target = NULL_RTX;

  /* If we are partitioning hot/cold basic blocks, we don't want to
     mess up unconditional or indirect jumps that cross between hot
     and cold sections.

     Basic block partitioning may result in some jumps that appear to
     be optimizable (or blocks that appear to be mergeable), but which really
     must be left untouched (they are required to make it safely across
     partition boundaries).  See  the comments at the top of
     bb-reorder.c:partition_hot_cold_basic_blocks for complete details.  */

  if ((BB_END (then_bb)
       && JUMP_P (BB_END (then_bb))
       && CROSSING_JUMP_P (BB_END (then_bb)))
      || (BB_END (test_bb)
	  && JUMP_P (BB_END (test_bb))
	  && CROSSING_JUMP_P (BB_END (test_bb)))
      || (BB_END (else_bb)
	  && JUMP_P (BB_END (else_bb))
	  && CROSSING_JUMP_P (BB_END (else_bb))))
    return FALSE;

  /* THEN has one successor.  */
  if (!single_succ_p (then_bb))
    return FALSE;

  /* THEN does not fall through, but is not strange either.  */
  if (single_succ_edge (then_bb)->flags & (EDGE_COMPLEX | EDGE_FALLTHRU))
    return FALSE;

  /* THEN has one predecessor.  */
  if (!single_pred_p (then_bb))
    return FALSE;

  /* THEN must do something.  */
  if (forwarder_block_p (then_bb))
    return FALSE;

  num_possible_if_blocks++;
  if (dump_file)
    fprintf (dump_file,
	     "\nIF-CASE-1 found, start %d, then %d\n",
	     test_bb->index, then_bb->index);

  if (then_edge->probability)
    then_prob = REG_BR_PROB_BASE - then_edge->probability;
  else
    then_prob = REG_BR_PROB_BASE / 2;

  /* We're speculating from the THEN path, we want to make sure the cost
     of speculation is within reason.  */
  if (! cheap_bb_rtx_cost_p (then_bb, then_prob,
	COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (then_edge->src),
				    predictable_edge_p (then_edge)))))
    return FALSE;

  if (else_bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      rtx_insn *jump = BB_END (else_edge->src);
      gcc_assert (JUMP_P (jump));
      else_target = JUMP_LABEL (jump);
    }

  /* Registers set are dead, or are predicable.  */
  if (! dead_or_predicable (test_bb, then_bb, else_bb,
			    single_succ_edge (then_bb), 1))
    return FALSE;

  /* Conversion went ok, including moving the insns and fixing up the
     jump.  Adjust the CFG to match.  */

  /* We can avoid creating a new basic block if then_bb is immediately
     followed by else_bb, i.e. deleting then_bb allows test_bb to fall
     through to else_bb.  */

  if (then_bb->next_bb == else_bb
      && then_bb->prev_bb == test_bb
      && else_bb != EXIT_BLOCK_PTR_FOR_FN (cfun))
    {
      redirect_edge_succ (FALLTHRU_EDGE (test_bb), else_bb);
      new_bb = 0;
    }
  else if (else_bb == EXIT_BLOCK_PTR_FOR_FN (cfun))
    new_bb = force_nonfallthru_and_redirect (FALLTHRU_EDGE (test_bb),
					     else_bb, else_target);
  else
    new_bb = redirect_edge_and_branch_force (FALLTHRU_EDGE (test_bb),
					     else_bb);

  df_set_bb_dirty (test_bb);
  df_set_bb_dirty (else_bb);

  then_bb_index = then_bb->index;
  delete_basic_block (then_bb);

  /* Make rest of code believe that the newly created block is the THEN_BB
     block we removed.  */
  if (new_bb)
    {
      df_bb_replace (then_bb_index, new_bb);
      /* This should have been done above via force_nonfallthru_and_redirect
         (possibly called from redirect_edge_and_branch_force).  */
      gcc_checking_assert (BB_PARTITION (new_bb) == BB_PARTITION (test_bb));
    }

  num_true_changes++;
  num_updated_if_blocks++;
  return TRUE;
}

/* Test for case 2 above.  */

static int
find_if_case_2 (basic_block test_bb, edge then_edge, edge else_edge)
{
  basic_block then_bb = then_edge->dest;
  basic_block else_bb = else_edge->dest;
  edge else_succ;
  int then_prob, else_prob;

  /* We do not want to speculate (empty) loop latches.  */
  if (current_loops
      && else_bb->loop_father->latch == else_bb)
    return FALSE;

  /* If we are partitioning hot/cold basic blocks, we don't want to
     mess up unconditional or indirect jumps that cross between hot
     and cold sections.

     Basic block partitioning may result in some jumps that appear to
     be optimizable (or blocks that appear to be mergeable), but which really
     must be left untouched (they are required to make it safely across
     partition boundaries).  See  the comments at the top of
     bb-reorder.c:partition_hot_cold_basic_blocks for complete details.  */

  if ((BB_END (then_bb)
       && JUMP_P (BB_END (then_bb))
       && CROSSING_JUMP_P (BB_END (then_bb)))
      || (BB_END (test_bb)
	  && JUMP_P (BB_END (test_bb))
	  && CROSSING_JUMP_P (BB_END (test_bb)))
      || (BB_END (else_bb)
	  && JUMP_P (BB_END (else_bb))
	  && CROSSING_JUMP_P (BB_END (else_bb))))
    return FALSE;

  /* ELSE has one successor.  */
  if (!single_succ_p (else_bb))
    return FALSE;
  else
    else_succ = single_succ_edge (else_bb);

  /* ELSE outgoing edge is not complex.  */
  if (else_succ->flags & EDGE_COMPLEX)
    return FALSE;

  /* ELSE has one predecessor.  */
  if (!single_pred_p (else_bb))
    return FALSE;

  /* THEN is not EXIT.  */
  if (then_bb->index < NUM_FIXED_BLOCKS)
    return FALSE;

  if (else_edge->probability)
    {
      else_prob = else_edge->probability;
      then_prob = REG_BR_PROB_BASE - else_prob;
    }
  else
    {
      else_prob = REG_BR_PROB_BASE / 2;
      then_prob = REG_BR_PROB_BASE / 2;
    }

  /* ELSE is predicted or SUCC(ELSE) postdominates THEN.  */
  if (else_prob > then_prob)
    ;
  else if (else_succ->dest->index < NUM_FIXED_BLOCKS
	   || dominated_by_p (CDI_POST_DOMINATORS, then_bb,
			      else_succ->dest))
    ;
  else
    return FALSE;

  num_possible_if_blocks++;
  if (dump_file)
    fprintf (dump_file,
	     "\nIF-CASE-2 found, start %d, else %d\n",
	     test_bb->index, else_bb->index);

  /* We're speculating from the ELSE path, we want to make sure the cost
     of speculation is within reason.  */
  if (! cheap_bb_rtx_cost_p (else_bb, else_prob,
	COSTS_N_INSNS (BRANCH_COST (optimize_bb_for_speed_p (else_edge->src),
				    predictable_edge_p (else_edge)))))
    return FALSE;

  /* Registers set are dead, or are predicable.  */
  if (! dead_or_predicable (test_bb, else_bb, then_bb, else_succ, 0))
    return FALSE;

  /* Conversion went ok, including moving the insns and fixing up the
     jump.  Adjust the CFG to match.  */

  df_set_bb_dirty (test_bb);
  df_set_bb_dirty (then_bb);
  delete_basic_block (else_bb);

  num_true_changes++;
  num_updated_if_blocks++;

  /* ??? We may now fallthru from one of THEN's successors into a join
     block.  Rerun cleanup_cfg?  Examine things manually?  Wait?  */

  return TRUE;
}

/* Used by the code above to perform the actual rtl transformations.
   Return TRUE if successful.

   TEST_BB is the block containing the conditional branch.  MERGE_BB
   is the block containing the code to manipulate.  DEST_EDGE is an
   edge representing a jump to the join block; after the conversion,
   TEST_BB should be branching to its destination.
   REVERSEP is true if the sense of the branch should be reversed.  */

static int
dead_or_predicable (basic_block test_bb, basic_block merge_bb,
		    basic_block other_bb, edge dest_edge, int reversep)
{
  basic_block new_dest = dest_edge->dest;
  rtx_insn *head, *end, *jump;
  rtx_insn *earliest = NULL;
  rtx old_dest;
  bitmap merge_set = NULL;
  /* Number of pending changes.  */
  int n_validated_changes = 0;
  rtx new_dest_label = NULL_RTX;

  jump = BB_END (test_bb);

  /* Find the extent of the real code in the merge block.  */
  head = BB_HEAD (merge_bb);
  end = BB_END (merge_bb);

  while (DEBUG_INSN_P (end) && end != head)
    end = PREV_INSN (end);

  /* If merge_bb ends with a tablejump, predicating/moving insn's
     into test_bb and then deleting merge_bb will result in the jumptable
     that follows merge_bb being removed along with merge_bb and then we
     get an unresolved reference to the jumptable.  */
  if (tablejump_p (end, NULL, NULL))
    return FALSE;

  if (LABEL_P (head))
    head = NEXT_INSN (head);
  while (DEBUG_INSN_P (head) && head != end)
    head = NEXT_INSN (head);
  if (NOTE_P (head))
    {
      if (head == end)
	{
	  head = end = NULL;
	  goto no_body;
	}
      head = NEXT_INSN (head);
      while (DEBUG_INSN_P (head) && head != end)
	head = NEXT_INSN (head);
    }

  if (JUMP_P (end))
    {
      if (!onlyjump_p (end))
	return FALSE;
      if (head == end)
	{
	  head = end = NULL;
	  goto no_body;
	}
      end = PREV_INSN (end);
      while (DEBUG_INSN_P (end) && end != head)
	end = PREV_INSN (end);
    }

  /* Don't move frame-related insn across the conditional branch.  This
     can lead to one of the paths of the branch having wrong unwind info.  */
  if (epilogue_completed)
    {
      rtx_insn *insn = head;
      while (1)
	{
	  if (INSN_P (insn) && RTX_FRAME_RELATED_P (insn))
	    return FALSE;
	  if (insn == end)
	    break;
	  insn = NEXT_INSN (insn);
	}
    }

  /* Disable handling dead code by conditional execution if the machine needs
     to do anything funny with the tests, etc.  */
#ifndef IFCVT_MODIFY_TESTS
  if (targetm.have_conditional_execution ())
    {
      /* In the conditional execution case, we have things easy.  We know
	 the condition is reversible.  We don't have to check life info
	 because we're going to conditionally execute the code anyway.
	 All that's left is making sure the insns involved can actually
	 be predicated.  */

      rtx cond;

      cond = cond_exec_get_condition (jump);
      if (! cond)
	return FALSE;

      rtx note = find_reg_note (jump, REG_BR_PROB, NULL_RTX);
      int prob_val = (note ? XINT (note, 0) : -1);

      if (reversep)
	{
	  enum rtx_code rev = reversed_comparison_code (cond, jump);
	  if (rev == UNKNOWN)
	    return FALSE;
	  cond = gen_rtx_fmt_ee (rev, GET_MODE (cond), XEXP (cond, 0),
			         XEXP (cond, 1));
	  if (prob_val >= 0)
	    prob_val = REG_BR_PROB_BASE - prob_val;
	}

      if (cond_exec_process_insns (NULL, head, end, cond, prob_val, 0)
	  && verify_changes (0))
	n_validated_changes = num_validated_changes ();
      else
	cancel_changes (0);

      earliest = jump;
    }
#endif

  /* If we allocated new pseudos (e.g. in the conditional move
     expander called from noce_emit_cmove), we must resize the
     array first.  */
  if (max_regno < max_reg_num ())
    max_regno = max_reg_num ();

  /* Try the NCE path if the CE path did not result in any changes.  */
  if (n_validated_changes == 0)
    {
      rtx cond;
      rtx_insn *insn;
      regset live;
      bool success;

      /* In the non-conditional execution case, we have to verify that there
	 are no trapping operations, no calls, no references to memory, and
	 that any registers modified are dead at the branch site.  */

      if (!any_condjump_p (jump))
	return FALSE;

      /* Find the extent of the conditional.  */
      cond = noce_get_condition (jump, &earliest, false);
      if (!cond)
	return FALSE;

      live = BITMAP_ALLOC (&reg_obstack);
      simulate_backwards_to_point (merge_bb, live, end);
      success = can_move_insns_across (head, end, earliest, jump,
				       merge_bb, live,
				       df_get_live_in (other_bb), NULL);
      BITMAP_FREE (live);
      if (!success)
	return FALSE;

      /* Collect the set of registers set in MERGE_BB.  */
      merge_set = BITMAP_ALLOC (&reg_obstack);

      FOR_BB_INSNS (merge_bb, insn)
	if (NONDEBUG_INSN_P (insn))
	  df_simulate_find_defs (insn, merge_set);

      /* If shrink-wrapping, disable this optimization when test_bb is
	 the first basic block and merge_bb exits.  The idea is to not
	 move code setting up a return register as that may clobber a
	 register used to pass function parameters, which then must be
	 saved in caller-saved regs.  A caller-saved reg requires the
	 prologue, killing a shrink-wrap opportunity.  */
      if ((SHRINK_WRAPPING_ENABLED && !epilogue_completed)
	  && ENTRY_BLOCK_PTR_FOR_FN (cfun)->next_bb == test_bb
	  && single_succ_p (new_dest)
	  && single_succ (new_dest) == EXIT_BLOCK_PTR_FOR_FN (cfun)
	  && bitmap_intersect_p (df_get_live_in (new_dest), merge_set))
	{
	  regset return_regs;
	  unsigned int i;

	  return_regs = BITMAP_ALLOC (&reg_obstack);

	  /* Start off with the intersection of regs used to pass
	     params and regs used to return values.  */
	  for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
	    if (FUNCTION_ARG_REGNO_P (i)
		&& targetm.calls.function_value_regno_p (i))
	      bitmap_set_bit (return_regs, INCOMING_REGNO (i));

	  bitmap_and_into (return_regs,
			   df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
	  bitmap_and_into (return_regs,
			   df_get_live_in (EXIT_BLOCK_PTR_FOR_FN (cfun)));
	  if (!bitmap_empty_p (return_regs))
	    {
	      FOR_BB_INSNS_REVERSE (new_dest, insn)
		if (NONDEBUG_INSN_P (insn))
		  {
		    df_ref def;

		    /* If this insn sets any reg in return_regs, add all
		       reg uses to the set of regs we're interested in.  */
		    FOR_EACH_INSN_DEF (def, insn)
		      if (bitmap_bit_p (return_regs, DF_REF_REGNO (def)))
			{
			  df_simulate_uses (insn, return_regs);
			  break;
			}
		  }
	      if (bitmap_intersect_p (merge_set, return_regs))
		{
		  BITMAP_FREE (return_regs);
		  BITMAP_FREE (merge_set);
		  return FALSE;
		}
	    }
	  BITMAP_FREE (return_regs);
	}
    }

 no_body:
  /* We don't want to use normal invert_jump or redirect_jump because
     we don't want to delete_insn called.  Also, we want to do our own
     change group management.  */

  old_dest = JUMP_LABEL (jump);
  if (other_bb != new_dest)
    {
      if (!any_condjump_p (jump))
	goto cancel;

      if (JUMP_P (BB_END (dest_edge->src)))
	new_dest_label = JUMP_LABEL (BB_END (dest_edge->src));
      else if (new_dest == EXIT_BLOCK_PTR_FOR_FN (cfun))
	new_dest_label = ret_rtx;
      else
	new_dest_label = block_label (new_dest);

      rtx_jump_insn *jump_insn = as_a <rtx_jump_insn *> (jump);
      if (reversep
	  ? ! invert_jump_1 (jump_insn, new_dest_label)
	  : ! redirect_jump_1 (jump_insn, new_dest_label))
	goto cancel;
    }

  if (verify_changes (n_validated_changes))
    confirm_change_group ();
  else
    goto cancel;

  if (other_bb != new_dest)
    {
      redirect_jump_2 (as_a <rtx_jump_insn *> (jump), old_dest, new_dest_label,
		       0, reversep);

      redirect_edge_succ (BRANCH_EDGE (test_bb), new_dest);
      if (reversep)
	{
	  std::swap (BRANCH_EDGE (test_bb)->count,
		     FALLTHRU_EDGE (test_bb)->count);
	  std::swap (BRANCH_EDGE (test_bb)->probability,
		     FALLTHRU_EDGE (test_bb)->probability);
	  update_br_prob_note (test_bb);
	}
    }

  /* Move the insns out of MERGE_BB to before the branch.  */
  if (head != NULL)
    {
      rtx_insn *insn;

      if (end == BB_END (merge_bb))
	BB_END (merge_bb) = PREV_INSN (head);

      /* PR 21767: when moving insns above a conditional branch, the REG_EQUAL
	 notes being moved might become invalid.  */
      insn = head;
      do
	{
	  rtx note;

	  if (! INSN_P (insn))
	    continue;
	  note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
	  if (! note)
	    continue;
	  remove_note (insn, note);
	} while (insn != end && (insn = NEXT_INSN (insn)));

      /* PR46315: when moving insns above a conditional branch, the REG_EQUAL
	 notes referring to the registers being set might become invalid.  */
      if (merge_set)
	{
	  unsigned i;
	  bitmap_iterator bi;

	  EXECUTE_IF_SET_IN_BITMAP (merge_set, 0, i, bi)
	    remove_reg_equal_equiv_notes_for_regno (i);

	  BITMAP_FREE (merge_set);
	}

      reorder_insns (head, end, PREV_INSN (earliest));
    }

  /* Remove the jump and edge if we can.  */
  if (other_bb == new_dest)
    {
      delete_insn (jump);
      remove_edge (BRANCH_EDGE (test_bb));
      /* ??? Can't merge blocks here, as then_bb is still in use.
	 At minimum, the merge will get done just before bb-reorder.  */
    }

  return TRUE;

 cancel:
  cancel_changes (0);

  if (merge_set)
    BITMAP_FREE (merge_set);

  return FALSE;
}

/* Main entry point for all if-conversion.  AFTER_COMBINE is true if
   we are after combine pass.  */

static void
if_convert (bool after_combine)
{
  basic_block bb;
  int pass;

  if (optimize == 1)
    {
      df_live_add_problem ();
      df_live_set_all_dirty ();
    }

  /* Record whether we are after combine pass.  */
  ifcvt_after_combine = after_combine;
  have_cbranchcc4 = (direct_optab_handler (cbranch_optab, CCmode)
		     != CODE_FOR_nothing);
  num_possible_if_blocks = 0;
  num_updated_if_blocks = 0;
  num_true_changes = 0;

  loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
  mark_loop_exit_edges ();
  loop_optimizer_finalize ();
  free_dominance_info (CDI_DOMINATORS);

  /* Compute postdominators.  */
  calculate_dominance_info (CDI_POST_DOMINATORS);

  df_set_flags (DF_LR_RUN_DCE);

  /* Go through each of the basic blocks looking for things to convert.  If we
     have conditional execution, we make multiple passes to allow us to handle
     IF-THEN{-ELSE} blocks within other IF-THEN{-ELSE} blocks.  */
  pass = 0;
  do
    {
      df_analyze ();
      /* Only need to do dce on the first pass.  */
      df_clear_flags (DF_LR_RUN_DCE);
      cond_exec_changed_p = FALSE;
      pass++;

#ifdef IFCVT_MULTIPLE_DUMPS
      if (dump_file && pass > 1)
	fprintf (dump_file, "\n\n========== Pass %d ==========\n", pass);
#endif

      FOR_EACH_BB_FN (bb, cfun)
	{
          basic_block new_bb;
          while (!df_get_bb_dirty (bb)
                 && (new_bb = find_if_header (bb, pass)) != NULL)
            bb = new_bb;
	}

#ifdef IFCVT_MULTIPLE_DUMPS
      if (dump_file && cond_exec_changed_p)
	print_rtl_with_bb (dump_file, get_insns (), dump_flags);
#endif
    }
  while (cond_exec_changed_p);

#ifdef IFCVT_MULTIPLE_DUMPS
  if (dump_file)
    fprintf (dump_file, "\n\n========== no more changes\n");
#endif

  free_dominance_info (CDI_POST_DOMINATORS);

  if (dump_file)
    fflush (dump_file);

  clear_aux_for_blocks ();

  /* If we allocated new pseudos, we must resize the array for sched1.  */
  if (max_regno < max_reg_num ())
    max_regno = max_reg_num ();

  /* Write the final stats.  */
  if (dump_file && num_possible_if_blocks > 0)
    {
      fprintf (dump_file,
	       "\n%d possible IF blocks searched.\n",
	       num_possible_if_blocks);
      fprintf (dump_file,
	       "%d IF blocks converted.\n",
	       num_updated_if_blocks);
      fprintf (dump_file,
	       "%d true changes made.\n\n\n",
	       num_true_changes);
    }

  if (optimize == 1)
    df_remove_problem (df_live);

  checking_verify_flow_info ();
}

/* If-conversion and CFG cleanup.  */
static unsigned int
rest_of_handle_if_conversion (void)
{
  if (flag_if_conversion)
    {
      if (dump_file)
	{
	  dump_reg_info (dump_file);
	  dump_flow_info (dump_file, dump_flags);
	}
      cleanup_cfg (CLEANUP_EXPENSIVE);
      if_convert (false);
    }

  cleanup_cfg (0);
  return 0;
}

namespace {

const pass_data pass_data_rtl_ifcvt =
{
  RTL_PASS, /* type */
  "ce1", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_IFCVT, /* tv_id */
  0, /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  TODO_df_finish, /* todo_flags_finish */
};

class pass_rtl_ifcvt : public rtl_opt_pass
{
public:
  pass_rtl_ifcvt (gcc::context *ctxt)
    : rtl_opt_pass (pass_data_rtl_ifcvt, ctxt)
  {}

  /* opt_pass methods: */
  virtual bool gate (function *)
    {
      return (optimize > 0) && dbg_cnt (if_conversion);
    }

  virtual unsigned int execute (function *)
    {
      return rest_of_handle_if_conversion ();
    }

}; // class pass_rtl_ifcvt

} // anon namespace

rtl_opt_pass *
make_pass_rtl_ifcvt (gcc::context *ctxt)
{
  return new pass_rtl_ifcvt (ctxt);
}


/* Rerun if-conversion, as combine may have simplified things enough
   to now meet sequence length restrictions.  */

namespace {

const pass_data pass_data_if_after_combine =
{
  RTL_PASS, /* type */
  "ce2", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_IFCVT, /* tv_id */
  0, /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  TODO_df_finish, /* todo_flags_finish */
};

class pass_if_after_combine : public rtl_opt_pass
{
public:
  pass_if_after_combine (gcc::context *ctxt)
    : rtl_opt_pass (pass_data_if_after_combine, ctxt)
  {}

  /* opt_pass methods: */
  virtual bool gate (function *)
    {
      return optimize > 0 && flag_if_conversion
	&& dbg_cnt (if_after_combine);
    }

  virtual unsigned int execute (function *)
    {
      if_convert (true);
      return 0;
    }

}; // class pass_if_after_combine

} // anon namespace

rtl_opt_pass *
make_pass_if_after_combine (gcc::context *ctxt)
{
  return new pass_if_after_combine (ctxt);
}


namespace {

const pass_data pass_data_if_after_reload =
{
  RTL_PASS, /* type */
  "ce3", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_IFCVT2, /* tv_id */
  0, /* properties_required */
  0, /* properties_provided */
  0, /* properties_destroyed */
  0, /* todo_flags_start */
  TODO_df_finish, /* todo_flags_finish */
};

class pass_if_after_reload : public rtl_opt_pass
{
public:
  pass_if_after_reload (gcc::context *ctxt)
    : rtl_opt_pass (pass_data_if_after_reload, ctxt)
  {}

  /* opt_pass methods: */
  virtual bool gate (function *)
    {
      return optimize > 0 && flag_if_conversion2
	&& dbg_cnt (if_after_reload);
    }

  virtual unsigned int execute (function *)
    {
      if_convert (true);
      return 0;
    }

}; // class pass_if_after_reload

} // anon namespace

rtl_opt_pass *
make_pass_if_after_reload (gcc::context *ctxt)
{
  return new pass_if_after_reload (ctxt);
}