aboutsummaryrefslogtreecommitdiffstats
path: root/contrib/gcc/gcc.1
blob: 74200a1a169e98a331ac31fba8341a2800073b7d (plain) (blame)
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
.\" Copyright (c) 1991, 1992, 1993, 1994 Free Software Foundation    -*-Text-*-
.\" See section COPYING for conditions for redistribution
.\"
.\" Set up \*(lq, \*(rq if -man hasn't already set it up.
.if @@\*(lq@ \{\
.	ds lq "
.	if t .ds lq ``
.	if !@@\(lq@ .ds lq "\(lq
.\}
.if @@\*(rq@ \{\
.	ds rq "
.	if t .ds rq ''
.	if !@@\(rq@ .ds rq "\(rq
.\}
.de Id
.ds Rv \\$3
.ds Dt \\$4
..
.de Sp
.if n .sp
.if t .sp 0.4
..
.Id $Id: gcc.1,v 1.9 1998/12/16 20:55:57 law Exp $
.TH GCC 1 "\*(Dt" "GNU Tools" "GNU Tools"
.SH NAME
gcc, g++ \- GNU project C and C++ Compiler (gcc-2.95)
.SH SYNOPSIS
.B gcc
.RI "[ " option " | " filename " ].\|.\|."
.br
.B g++
.RI "[ " option " | " filename " ].\|.\|."
.SH WARNING
The information in this man page is an extract from the full
documentation of the GNU C compiler, and is limited to the meaning of
the options.
.PP
This man page is not kept up to date except when volunteers want to
maintain it.  If you find a discrepancy between the man page and the
software, please check the Info file, which is the authoritative
documentation.
.PP
If we find that the things in this man page that are out of date cause
significant confusion or complaints, we will stop distributing the man
page.  The alternative, updating the man page when we update the Info
file, is impossible because the rest of the work of maintaining GNU CC
leaves us no time for that.  The GNU project regards man pages as
obsolete and should not let them take time away from other things.
.PP
For complete and current documentation, refer to the Info file `\|\c
.B gcc\c
\&\|' or the manual
.I
Using and Porting GNU CC (for version 2.0)\c
\&.  Both are made from the Texinfo source file
.BR gcc.texinfo .
.SH DESCRIPTION
The C and C++ compilers are integrated.  Both process input files
through one or more of four stages: preprocessing, compilation,
assembly, and linking.  Source filename suffixes identify the source
language, but which name you use for the compiler governs default
assumptions:
.TP
.B gcc
assumes preprocessed (\c
.B .i\c
\&) files are C and assumes C style linking.
.TP
.B g++
assumes preprocessed (\c
.B .i\c
\&) files are C++ and assumes C++ style linking.
.PP
Suffixes of source file names indicate the language and kind of
processing to be done:
.Sp
.nf
.ta \w'\fB.cxx\fP  'u
\&\fB.c\fP	C source; preprocess, compile, assemble
\&\fB.C\fP	C++ source; preprocess, compile, assemble
\&\fB.cc\fP	C++ source; preprocess, compile, assemble
\&\fB.cxx\fP	C++ source; preprocess, compile, assemble
\&\fB.m\fP	Objective-C source; preprocess, compile, assemble
\&\fB.i\fP	preprocessed C; compile, assemble
\&\fB.ii\fP	preprocessed C++; compile, assemble
\&\fB.s\fP	Assembler source; assemble
\&\fB.S\fP	Assembler source; preprocess, assemble
\&\fB.h\fP	Preprocessor file; not usually named on command line
.Sp
.fi
Files with other suffixes are passed to the linker.  Common cases include:
.Sp
.nf
\&\fB.o\fP	Object file
\&\fB.a\fP	Archive file
.br
.fi
.Sp
Linking is always the last stage unless you use one of the
.BR \-c ,
.BR \-S ,
or
.B \-E
options to avoid it (or unless compilation errors stop the whole
process).  For the link stage, all
.B .o
files corresponding to source files,
.B \-l
libraries, unrecognized filenames (including named
.B .o
object files and
.B .a
archives)
are passed to the linker in command-line order.
.SH OPTIONS
Options must be separate: `\|\c
.B \-dr\c
\&\|' is quite different from `\|\c
.B \-d \-r
\&\|'.
.PP
Most `\|\c
.B \-f\c
\&\|' and `\|\c
.B \-W\c
\&\|' options have two contrary forms:
.BI \-f name
and
.BI \-fno\- name\c
\& (or
.BI \-W name
and
.BI \-Wno\- name\c
\&).  Only the non-default forms are shown here.
.PP
Here is a summary of all the options, grouped by type.  Explanations are
in the following sections.
.hy 0
.na
.TP
.B Overall Options
.br
\-c
\-S
\-E
.RI "\-o " file
\-pipe
\-v
.RI "\-x " language
.TP
.B Language Options
\-ansi
\-fall\-virtual
\-fcond\-mismatch
\-fdollars\-in\-identifiers
\-fenum\-int\-equiv
\-fexternal\-templates
\-fno\-asm
\-fno\-builtin
\-fhosted
\-fno\-hosted
\-ffreestanding
\-fno\-freestanding
\-fno\-strict\-prototype
\-fsigned\-bitfields
\-fsigned\-char
\-fthis\-is\-variable
\-funsigned\-bitfields
\-funsigned\-char
\-fwritable\-strings
\-traditional
\-traditional\-cpp
\-trigraphs
.TP
.B Warning Options
\-fsyntax\-only
\-pedantic
\-pedantic\-errors
\-w
\-W
\-Wall
\-Waggregate\-return
\-Wcast\-align
\-Wcast\-qual
\-Wchar\-subscript
\-Wcomment
\-Wconversion
\-Wenum\-clash
\-Werror
\-Wformat
.RI \-Wid\-clash\- len
\-Wimplicit
\-Wimplicit\-int
\-Wimplicit\-function\-declaration
\-Winline
\-Wlong\-long
\-Wmain
\-Wmissing\-prototypes
\-Wmissing\-declarations
\-Wnested\-externs
\-Wno\-import
\-Wparentheses
\-Wpointer\-arith
\-Wredundant\-decls
\-Wreturn\-type
\-Wshadow
\-Wstrict\-prototypes
\-Wswitch
\-Wtemplate\-debugging
\-Wtraditional
\-Wtrigraphs
\-Wuninitialized
\-Wunused
\-Wwrite\-strings
.TP
.B Debugging Options
\-a
.RI \-d letters
\-fpretend\-float
\-g
.RI \-g level
\-gcoff
\-gxcoff
\-gxcoff+
\-gdwarf
\-gdwarf+
\-gstabs
\-gstabs+
\-ggdb
\-p
\-pg
\-save\-temps
.RI \-print\-file\-name= library
\-print\-libgcc\-file\-name
.RI \-print\-prog\-name= program
.TP
.B Optimization Options
\-fcaller\-saves
\-fcse\-follow\-jumps
\-fcse\-skip\-blocks
\-fdelayed\-branch
\-felide\-constructors
\-fexpensive\-optimizations
\-ffast\-math
\-ffloat\-store
\-fforce\-addr
\-fforce\-mem
\-finline\-functions
\-fkeep\-inline\-functions
\-fmemoize\-lookups
\-fno\-default\-inline
\-fno\-defer\-pop
\-fno\-function\-cse
\-fno\-inline
\-fno\-peephole
\-fomit\-frame\-pointer
\-frerun\-cse\-after\-loop
\-fschedule\-insns
\-fschedule\-insns2
\-fstrength\-reduce
\-fthread\-jumps
\-funroll\-all\-loops
\-funroll\-loops
\-O
\-O2
\-O3
.TP
.B Preprocessor Options
.RI \-A assertion
\-C
\-dD
\-dM
\-dN
.RI \-D macro [\|= defn \|]
\-E
\-H
.RI "\-idirafter " dir
.RI "\-include " file
.RI "\-imacros " file
.RI "\-iprefix " file
.RI "\-iwithprefix " dir
\-M
\-MD
\-MM
\-MMD
\-nostdinc
\-P
.RI \-U macro
\-undef
.TP
.B Assembler Option
.RI \-Wa, option
.TP
.B Linker Options
.RI \-l library
\-nostartfiles
\-nostdlib
\-static
\-shared
\-symbolic
.RI "\-Xlinker\ " option
.RI \-Wl, option
.RI "\-u " symbol
.TP
.B Directory Options
.RI \-B prefix
.RI \-I dir
\-I\-
.RI \-L dir
.TP
.B Target Options
.RI "\-b  " machine
.RI "\-V " version
.TP
.B Configuration Dependent Options
.I M680x0\ Options
.br
\-m68000
\-m68020
\-m68020\-40
\-m68030
\-m68040
\-m68881
\-mbitfield
\-mc68000
\-mc68020
\-mfpa
\-mnobitfield
\-mrtd
\-mshort
\-msoft\-float
.Sp
.I VAX Options
.br
\-mg
\-mgnu
\-munix
.Sp
.I SPARC Options
.br
\-mepilogue
\-mfpu
\-mhard\-float
\-mno\-fpu
\-mno\-epilogue
\-msoft\-float
\-msparclite
\-mv8
\-msupersparc
\-mcypress
.Sp
.I Convex Options
.br
\-margcount
\-mc1
\-mc2
\-mnoargcount
.Sp
.I AMD29K Options
.br
\-m29000
\-m29050
\-mbw
\-mdw
\-mkernel\-registers
\-mlarge
\-mnbw
\-mnodw
\-msmall
\-mstack\-check
\-muser\-registers
.Sp
.I M88K Options
.br
\-m88000
\-m88100
\-m88110
\-mbig\-pic
\-mcheck\-zero\-division
\-mhandle\-large\-shift
\-midentify\-revision
\-mno\-check\-zero\-division
\-mno\-ocs\-debug\-info
\-mno\-ocs\-frame\-position
\-mno\-optimize\-arg\-area
\-mno\-serialize\-volatile
\-mno\-underscores
\-mocs\-debug\-info
\-mocs\-frame\-position
\-moptimize\-arg\-area
\-mserialize\-volatile
.RI \-mshort\-data\- num
\-msvr3
\-msvr4
\-mtrap\-large\-shift
\-muse\-div\-instruction
\-mversion\-03.00
\-mwarn\-passed\-structs
.Sp
.I RS6000 Options
.br
\-mfp\-in\-toc
\-mno\-fop\-in\-toc
.Sp
.I RT Options
.br
\-mcall\-lib\-mul
\-mfp\-arg\-in\-fpregs
\-mfp\-arg\-in\-gregs
\-mfull\-fp\-blocks
\-mhc\-struct\-return
\-min\-line\-mul
\-mminimum\-fp\-blocks
\-mnohc\-struct\-return
.Sp
.I MIPS Options
.br
\-mcpu=\fIcpu type\fP
\-mips2
\-mips3
\-mint64
\-mlong64
\-mlonglong128
\-mmips\-as
\-mgas
\-mrnames
\-mno\-rnames
\-mgpopt
\-mno\-gpopt
\-mstats
\-mno\-stats
\-mmemcpy
\-mno\-memcpy
\-mno\-mips\-tfile
\-mmips\-tfile
\-msoft\-float
\-mhard\-float
\-mabicalls
\-mno\-abicalls
\-mhalf\-pic
\-mno\-half\-pic
\-G \fInum\fP
\-nocpp
.Sp
.I i386 Options
.br
\-m486
\-mno\-486
\-msoft\-float
\-mno\-fp\-ret\-in\-387
.Sp
.I HPPA Options
.br
\-mpa\-risc\-1\-0
\-mpa\-risc\-1\-1
\-mkernel
\-mshared\-libs
\-mno\-shared\-libs
\-mlong\-calls
\-mdisable\-fpregs
\-mdisable\-indexing
\-mtrailing\-colon
.Sp
.I i960 Options
.br
\-m\fIcpu-type\fP
\-mnumerics
\-msoft\-float
\-mleaf\-procedures
\-mno\-leaf\-procedures
\-mtail\-call
\-mno\-tail\-call
\-mcomplex\-addr
\-mno\-complex\-addr
\-mcode\-align
\-mno\-code\-align
\-mic\-compat
\-mic2.0\-compat
\-mic3.0\-compat
\-masm\-compat
\-mintel\-asm
\-mstrict\-align
\-mno\-strict\-align
\-mold\-align
\-mno\-old\-align
.Sp
.I DEC Alpha Options
.br
\-mfp\-regs
\-mno\-fp\-regs
\-mno\-soft\-float
\-msoft\-float
.Sp
.I System V Options
.br
\-G
\-Qy
\-Qn
.RI \-YP, paths
.RI \-Ym, dir
.TP
.B Code Generation Options
.RI \-fcall\-saved\- reg
.RI \-fcall\-used\- reg
.RI \-ffixed\- reg
\-finhibit\-size\-directive
\-fnonnull\-objects
\-fno\-common
\-fno\-ident
\-fno\-gnu\-linker
\-fpcc\-struct\-return
\-fpic
\-fPIC
\-freg\-struct\-return
\-fshared\-data
\-fshort\-enums
\-fshort\-double
\-fvolatile
\-fvolatile\-global
\-fverbose\-asm
.ad b
.hy 1
.SH OVERALL OPTIONS
.TP
.BI "\-x " "language"
Specify explicitly the
.I language\c
\& for the following input files (rather than choosing a default based
on the file name suffix) .  This option applies to all following input
files until the next `\|\c
.B \-x\c
\&\|' option.  Possible values of \c
.I language\c
\& are
`\|\c
.B c\c
\&\|', `\|\c
.B objective\-c\c
\&\|', `\|\c
.B c\-header\c
\&\|', `\|\c
.B c++\c
\&\|',
`\|\c
.B cpp\-output\c
\&\|', `\|\c
.B assembler\c
\&\|', and `\|\c
.B assembler\-with\-cpp\c
\&\|'.
.TP
.B \-x none
Turn off any specification of a language, so that subsequent files are
handled according to their file name suffixes (as they are if `\|\c
.B \-x\c
\&\|'
has not been used at all).
.PP
If you want only some of the four stages (preprocess, compile,
assemble, link), you can use
`\|\c
.B \-x\c
\&\|' (or filename suffixes) to tell \c
.B gcc\c
\& where to start, and
one of the options `\|\c
.B \-c\c
\&\|', `\|\c
.B \-S\c
\&\|', or `\|\c
.B \-E\c
\&\|' to say where
.B gcc\c
\& is to stop.  Note that some combinations (for example,
`\|\c
.B \-x cpp\-output \-E\c
\&\|') instruct \c
.B gcc\c
\& to do nothing at all.
.TP
.B \-c
Compile or assemble the source files, but do not link.  The compiler
output is an object file corresponding to each source file.
.Sp
By default, GCC makes the object file name for a source file by replacing
the suffix `\|\c
.B .c\c
\&\|', `\|\c
.B .i\c
\&\|', `\|\c
.B .s\c
\&\|', etc., with `\|\c
.B .o\c
\&\|'.  Use
.B \-o\c
\& to select another name.
.Sp
GCC ignores any unrecognized input files (those that do not require
compilation or assembly) with the
.B \-c
option.
.TP
.B \-S
Stop after the stage of compilation proper; do not assemble.  The output
is an assembler code file for each non-assembler input
file specified.
.Sp
By default, GCC makes the assembler file name for a source file by
replacing the suffix `\|\c
.B .c\c
\&\|', `\|\c
.B .i\c
\&\|', etc., with `\|\c
.B .s\c
\&\|'.  Use
.B \-o\c
\& to select another name.
.Sp
GCC ignores any input files that don't require compilation.
.TP
.B \-E
Stop after the preprocessing stage; do not run the compiler proper.  The
output is preprocessed source code, which is sent to the
standard output.
.Sp
GCC ignores input files which don't require preprocessing.
.TP
.BI "\-o " file
Place output in file \c
.I file\c
\&.  This applies regardless to whatever
sort of output GCC is producing, whether it be an executable file,
an object file, an assembler file or preprocessed C code.
.Sp
Since only one output file can be specified, it does not make sense to
use `\|\c
.B \-o\c
\&\|' when compiling more than one input file, unless you are
producing an executable file as output.
.Sp
If you do not specify `\|\c
.B \-o\c
\&\|', the default is to put an executable file
in `\|\c
.B a.out\c
\&\|', the object file for `\|\c
.I source\c
.B \&.\c
.I suffix\c
\&\c
\&\|' in
`\|\c
.I source\c
.B \&.o\c
\&\|', its assembler file in `\|\c
.I source\c
.B \&.s\c
\&\|', and
all preprocessed C source on standard output.
.TP
.B \-v
Print (on standard error output) the commands executed to run the stages
of compilation.  Also print the version number of the compiler driver
program and of the preprocessor and the compiler proper.
.TP
.B \-pipe
Use pipes rather than temporary files for communication between the
various stages of compilation.  This fails to work on some systems where
the assembler cannot read from a pipe; but the GNU assembler has
no trouble.
.PP
.SH LANGUAGE OPTIONS
The following options control the dialect of C that the compiler
accepts:
.TP
.B \-ansi
Support all ANSI standard C programs.
.Sp
This turns off certain features of GNU C that are incompatible with
ANSI C, such as the \c
.B asm\c
\&, \c
.B inline\c
\& and \c
.B typeof
keywords, and predefined macros such as \c
.B unix\c
\& and \c
.B vax
that identify the type of system you are using.  It also enables the
undesirable and rarely used ANSI trigraph feature, and disallows `\|\c
.B $\c
\&\|' as part of identifiers.
.Sp
The alternate keywords \c
.B _\|_asm_\|_\c
\&, \c
.B _\|_extension_\|_\c
\&,
.B _\|_inline_\|_\c
\& and \c
.B _\|_typeof_\|_\c
\& continue to work despite
`\|\c
.B \-ansi\c
\&\|'.  You would not want to use them in an ANSI C program, of
course, but it is useful to put them in header files that might be included
in compilations done with `\|\c
.B \-ansi\c
\&\|'.  Alternate predefined macros
such as \c
.B _\|_unix_\|_\c
\& and \c
.B _\|_vax_\|_\c
\& are also available, with or
without `\|\c
.B \-ansi\c
\&\|'.
.Sp
The `\|\c
.B \-ansi\c
\&\|' option does not cause non-ANSI programs to be
rejected gratuitously.  For that, `\|\c
.B \-pedantic\c
\&\|' is required in
addition to `\|\c
.B \-ansi\c
\&\|'.
.Sp
The preprocessor predefines a macro \c
.B _\|_STRICT_ANSI_\|_\c
\& when you use the `\|\c
.B \-ansi\c
\&\|'
option.  Some header files may notice this macro and refrain
from declaring certain functions or defining certain macros that the
ANSI standard doesn't call for; this is to avoid interfering with any
programs that might use these names for other things.
.TP
.B \-fno\-asm
Do not recognize \c
.B asm\c
\&, \c
.B inline\c
\& or \c
.B typeof\c
\& as a
keyword.  These words may then be used as identifiers.  You can
use \c
.B _\|_asm_\|_\c
\&, \c
.B _\|_inline_\|_\c
\& and \c
.B _\|_typeof_\|_\c
\& instead.
`\|\c
.B \-ansi\c
\&\|' implies `\|\c
.B \-fno\-asm\c
\&\|'.
.TP
.B \-fno\-builtin
Don't recognize built-in functions that do not begin with two leading
underscores.  Currently, the functions affected include \c
.B _exit\c
\&,
.B abort\c
\&, \c
.B abs\c
\&, \c
.B alloca\c
\&, \c
.B cos\c
\&, \c
.B exit\c
\&,
.B fabs\c
\&, \c
.B labs\c
\&, \c
.B memcmp\c
\&, \c
.B memcpy\c
\&, \c
.B sin\c
\&,
.B sqrt\c
\&, \c
.B strcmp\c
\&, \c
.B strcpy\c
\&, and \c
.B strlen\c
\&.
.Sp
The `\|\c
.B \-ansi\c
\&\|' option prevents \c
.B alloca\c
\& and \c
.B _exit\c
\& from
being builtin functions.
.TP
.B \-fhosted
Compile for a hosted environment; this implies the `\|\c
.B \-fbuiltin\c
\&\|' option, and implies that suspicious declarations of
.B main\c
\& should be warned about.
.TP
.B \-ffreestanding
Compile for a freestanding environment; this implies the `\|\c
.B \-fno-builtin\c
\&\|' option, and implies that
.B main\c
\& has no special requirements.
.TP
.B \-fno\-strict\-prototype
Treat a function declaration with no arguments, such as `\|\c
.B int foo
();\c
\&\|', as C would treat it\(em\&as saying nothing about the number of
arguments or their types (C++ only).  Normally, such a declaration in
C++ means that the function \c
.B foo\c
\& takes no arguments.
.TP
.B \-trigraphs
Support ANSI C trigraphs.  The `\|\c
.B \-ansi\c
\&\|' option implies `\|\c
.B \-trigraphs\c
\&\|'.
.TP
.B \-traditional
Attempt to support some aspects of traditional C compilers.
For details, see the GNU C Manual; the duplicate list here
has been deleted so that we won't get complaints when it
is out of date.
.Sp
But one note about C++ programs only (not C).  `\|\c
.B \-traditional\c
\&\|' has one additional effect for C++: assignment to
.B this
is permitted.  This is the same as the effect of `\|\c
.B \-fthis\-is\-variable\c
\&\|'.
.TP
.B \-traditional\-cpp
Attempt to support some aspects of traditional C preprocessors.
This includes the items that specifically mention the preprocessor above,
but none of the other effects of `\|\c
.B \-traditional\c
\&\|'.
.TP
.B \-fdollars\-in\-identifiers
Permit the use of `\|\c
.B $\c
\&\|' in identifiers (C++ only).  You can also use
`\|\c
.B \-fno\-dollars\-in\-identifiers\c
\&\|' to explicitly prohibit use of
`\|\c
.B $\c
\&\|'.  (GNU C++ allows `\|\c
.B $\c
\&\|' by default on some target systems
but not others.)
.TP
.B \-fenum\-int\-equiv
Permit implicit conversion of \c
.B int\c
\& to enumeration types (C++
only).  Normally GNU C++ allows conversion of \c
.B enum\c
\& to \c
.B int\c
\&,
but not the other way around.
.TP
.B \-fexternal\-templates
Produce smaller code for template declarations, by generating only a
single copy of each template function where it is defined (C++ only).
To use this option successfully, you must also mark all files that
use templates with either `\|\c
.B #pragma implementation\c
\&\|' (the definition) or
`\|\c
.B #pragma interface\c
\&\|' (declarations).

When your code is compiled with `\|\c
.B \-fexternal\-templates\c
\&\|', all
template instantiations are external.  You must arrange for all
necessary instantiations to appear in the implementation file; you can
do this with a \c
.B typedef\c
\& that references each instantiation needed.
Conversely, when you compile using the default option
`\|\c
.B \-fno\-external\-templates\c
\&\|', all template instantiations are
explicitly internal.
.TP
.B \-fall\-virtual
Treat all possible member functions as virtual, implicitly.  All
member functions (except for constructor functions and
.B new
or
.B delete
member operators) are treated as virtual functions of the class where
they appear.
.Sp
This does not mean that all calls to these member functions will be
made through the internal table of virtual functions.  Under some
circumstances, the compiler can determine that a call to a given
virtual function can be made directly; in these cases the calls are
direct in any case.
.TP
.B \-fcond\-mismatch
Allow conditional expressions with mismatched types in the second and
third arguments.  The value of such an expression is void.
.TP
.B \-fthis\-is\-variable
Permit assignment to \c
.B this\c
\& (C++ only).  The incorporation of
user-defined free store management into C++ has made assignment to
`\|\c
.B this\c
\&\|' an anachronism.  Therefore, by default it is invalid to
assign to \c
.B this\c
\& within a class member function.  However, for
backwards compatibility, you can make it valid with
`\|\c
.B \-fthis-is-variable\c
\&\|'.
.TP
.B \-funsigned\-char
Let the type \c
.B char\c
\& be unsigned, like \c
.B unsigned char\c
\&.
.Sp
Each kind of machine has a default for what \c
.B char\c
\& should
be.  It is either like \c
.B unsigned char\c
\& by default or like
.B signed char\c
\& by default.
.Sp
Ideally, a portable program should always use \c
.B signed char\c
\& or
.B unsigned char\c
\& when it depends on the signedness of an object.
But many programs have been written to use plain \c
.B char\c
\& and
expect it to be signed, or expect it to be unsigned, depending on the
machines they were written for.  This option, and its inverse, let you
make such a program work with the opposite default.
.Sp
The type \c
.B char\c
\& is always a distinct type from each of
.B signed char\c
\& and \c
.B unsigned char\c
\&, even though its behavior
is always just like one of those two.
.TP
.B \-fsigned\-char
Let the type \c
.B char\c
\& be signed, like \c
.B signed char\c
\&.
.Sp
Note that this is equivalent to `\|\c
.B \-fno\-unsigned\-char\c
\&\|', which is
the negative form of `\|\c
.B \-funsigned\-char\c
\&\|'.  Likewise,
`\|\c
.B \-fno\-signed\-char\c
\&\|' is equivalent to `\|\c
.B \-funsigned\-char\c
\&\|'.
.TP
.B \-fsigned\-bitfields
.TP
.B \-funsigned\-bitfields
.TP
.B \-fno\-signed\-bitfields
.TP
.B \-fno\-unsigned\-bitfields
These options control whether a bitfield is
signed or unsigned, when declared with no explicit `\|\c
.B signed\c
\&\|' or `\|\c
.B unsigned\c
\&\|' qualifier.  By default, such a bitfield is
signed, because this is consistent: the basic integer types such as
.B int\c
\& are signed types.
.Sp
However, when you specify `\|\c
.B \-traditional\c
\&\|', bitfields are all unsigned
no matter what.
.TP
.B \-fwritable\-strings
Store string constants in the writable data segment and don't uniquize
them.  This is for compatibility with old programs which assume they
can write into string constants.  `\|\c
.B \-traditional\c
\&\|' also has this
effect.
.Sp
Writing into string constants is a very bad idea; \*(lqconstants\*(rq should
be constant.
.SH PREPROCESSOR OPTIONS
These options control the C preprocessor, which is run on each C source
file before actual compilation.
.PP
If you use the `\|\c
.B \-E\c
\&\|' option, GCC does nothing except preprocessing.
Some of these options make sense only together with `\|\c
.B \-E\c
\&\|' because
they cause the preprocessor output to be unsuitable for actual
compilation.
.TP
.BI "\-include " "file"
Process \c
.I file\c
\& as input before processing the regular input file.
In effect, the contents of \c
.I file\c
\& are compiled first.  Any `\|\c
.B \-D\c
\&\|'
and `\|\c
.B \-U\c
\&\|' options on the command line are always processed before
`\|\c
.B \-include \c
.I file\c
\&\c
\&\|', regardless of the order in which they are
written.  All the `\|\c
.B \-include\c
\&\|' and `\|\c
.B \-imacros\c
\&\|' options are
processed in the order in which they are written.
.TP
.BI "\-imacros " file
Process \c
.I file\c
\& as input, discarding the resulting output, before
processing the regular input file.  Because the output generated from
.I file\c
\& is discarded, the only effect of `\|\c
.B \-imacros \c
.I file\c
\&\c
\&\|' is to
make the macros defined in \c
.I file\c
\& available for use in the main
input.  The preprocessor evaluates any `\|\c
.B \-D\c
\&\|' and `\|\c
.B \-U\c
\&\|' options
on the command line before processing `\|\c
.B \-imacros\c
.I file\c
\&\|', regardless of the order in
which they are written.  All the `\|\c
.B \-include\c
\&\|' and `\|\c
.B \-imacros\c
\&\|'
options are processed in the order in which they are written.
.TP
.BI "\-idirafter " "dir"
Add the directory \c
.I dir\c
\& to the second include path.  The directories
on the second include path are searched when a header file is not found
in any of the directories in the main include path (the one that
`\|\c
.B \-I\c
\&\|' adds to).
.TP
.BI "\-iprefix " "prefix"
Specify \c
.I prefix\c
\& as the prefix for subsequent `\|\c
.B \-iwithprefix\c
\&\|'
options.
.TP
.BI "\-iwithprefix " "dir"
Add a directory to the second include path.  The directory's name is
made by concatenating \c
.I prefix\c
\& and \c
.I dir\c
\&, where \c
.I prefix
was specified previously with `\|\c
.B \-iprefix\c
\&\|'.
.TP
.B \-nostdinc
Do not search the standard system directories for header files.  Only
the directories you have specified with `\|\c
.B \-I\c
\&\|' options (and the
current directory, if appropriate) are searched.
.Sp
By using both `\|\c
.B \-nostdinc\c
\&\|' and `\|\c
.B \-I\-\c
\&\|', you can limit the include-file search file to only those
directories you specify explicitly.
.TP
.B \-nostdinc++
Do not search for header files in the C++\-specific standard directories,
but do still search the other standard directories.
(This option is used when building `\|\c
.B libg++\c
\&\|'.)
.TP
.B \-undef
Do not predefine any nonstandard macros.  (Including architecture flags).
.TP
.B \-E
Run only the C preprocessor.  Preprocess all the C source files
specified and output the results to standard output or to the
specified output file.
.TP
.B \-C
Tell the preprocessor not to discard comments.  Used with the
`\|\c
.B \-E\c
\&\|' option.
.TP
.B \-P
Tell the preprocessor not to generate `\|\c
.B #line\c
\&\|' commands.
Used with the `\|\c
.B \-E\c
\&\|' option.
.TP
.B \-M\  [ \-MG ]
Tell the preprocessor to output a rule suitable for \c
.B make
describing the dependencies of each object file.  For each source file,
the preprocessor outputs one \c
.B make\c
\&-rule whose target is the object
file name for that source file and whose dependencies are all the files
`\|\c
.B #include\c
\&\|'d in it.  This rule may be a single line or may be
continued with `\|\c
.B \e\c
\&\|'-newline if it is long.  The list of rules is
printed on standard output instead of the preprocessed C program.
.Sp
`\|\c
.B \-M\c
\&\|' implies `\|\c
.B \-E\c
\&\|'.
.Sp
`\|\c
.B \-MG\c
\&\|' says to treat missing header files as generated files and assume \c
they live in the same directory as the source file.  It must be specified \c
in addition to `\|\c
.B \-M\c
\&\|'.
.TP
.B \-MM\  [ \-MG ]
Like `\|\c
.B \-M\c
\&\|' but the output mentions only the user header files
included with `\|\c
.B #include "\c
.I file\c
\&"\c
\&\|'.  System header files
included with `\|\c
.B #include <\c
.I file\c
\&>\c
\&\|' are omitted.
.TP
.B \-MD
Like `\|\c
.B \-M\c
\&\|' but the dependency information is written to files with
names made by replacing `\|\c
.B .o\c
\&\|' with `\|\c
.B .d\c
\&\|' at the end of the
output file names.  This is in addition to compiling the file as
specified\(em\&`\|\c
.B \-MD\c
\&\|' does not inhibit ordinary compilation the way
`\|\c
.B \-M\c
\&\|' does.
.Sp
The Mach utility `\|\c
.B md\c
\&\|' can be used to merge the `\|\c
.B .d\c
\&\|' files
into a single dependency file suitable for using with the `\|\c
.B make\c
\&\|'
command.
.TP
.B \-MMD
Like `\|\c
.B \-MD\c
\&\|' except mention only user header files, not system
header files.
.TP
.B \-H
Print the name of each header file used, in addition to other normal
activities.
.TP
.BI "\-A" "question" ( answer )
Assert the answer
.I answer
for
.I question\c
\&, in case it is tested
with a preprocessor conditional such as `\|\c
.BI "#if #" question ( answer )\c
\&\|'.  `\|\c
.B \-A\-\c
\&\|' disables the standard
assertions that normally describe the target machine.
.TP
.BI "\-A" "question"\c
\&(\c
.I answer\c
\&)
Assert the answer \c
.I answer\c
\& for \c
.I question\c
\&, in case it is tested
with a preprocessor conditional such as `\|\c
.B #if
#\c
.I question\c
\&(\c
.I answer\c
\&)\c
\&\|'.  `\|\c
.B \-A-\c
\&\|' disables the standard
assertions that normally describe the target machine.
.TP
.BI \-D macro
Define macro \c
.I macro\c
\& with the string `\|\c
.B 1\c
\&\|' as its definition.
.TP
.BI \-D macro = defn
Define macro \c
.I macro\c
\& as \c
.I defn\c
\&.    All instances of `\|\c
.B \-D\c
\&\|' on
the command line are processed before any `\|\c
.B \-U\c
\&\|' options.
.TP
.BI \-U macro
Undefine macro \c
.I macro\c
\&.  `\|\c
.B \-U\c
\&\|' options are evaluated after all `\|\c
.B \-D\c
\&\|' options, but before any `\|\c
.B \-include\c
\&\|' and `\|\c
.B \-imacros\c
\&\|' options.
.TP
.B \-dM
Tell the preprocessor to output only a list of the macro definitions
that are in effect at the end of preprocessing.  Used with the `\|\c
.B \-E\c
\&\|'
option.
.TP
.B \-dD
Tell the preprocessor to pass all macro definitions into the output, in
their proper sequence in the rest of the output.
.TP
.B \-dN
Like `\|\c
.B \-dD\c
\&\|' except that the macro arguments and contents are omitted.
Only `\|\c
.B #define \c
.I name\c
\&\c
\&\|' is included in the output.
.SH ASSEMBLER OPTION
.TP
.BI "\-Wa," "option"
Pass \c
.I option\c
\& as an option to the assembler.  If \c
.I option
contains commas, it is split into multiple options at the commas.
.SH LINKER OPTIONS
These options come into play when the compiler links object files into
an executable output file.  They are meaningless if the compiler is
not doing a link step.
.TP
.I object-file-name
A file name that does not end in a special recognized suffix is
considered to name an object file or library.  (Object files are
distinguished from libraries by the linker according to the file
contents.)  If GCC does a link step, these object files are used as input
to the linker.
.TP
.BI \-l library
Use the library named \c
.I library\c
\& when linking.
.Sp
The linker searches a standard list of directories for the library,
which is actually a file named `\|\c
.B lib\c
.I library\c
\&.a\c
\&\|'.  The linker
then uses this file as if it had been specified precisely by name.
.Sp
The directories searched include several standard system directories
plus any that you specify with `\|\c
.B \-L\c
\&\|'.
.Sp
Normally the files found this way are library files\(em\&archive files
whose members are object files.  The linker handles an archive file by
scanning through it for members which define symbols that have so far
been referenced but not defined.  However, if the linker finds an
ordinary object file rather than a library, the object file is linked
in the usual fashion.  The only difference between using an `\|\c
.B \-l\c
\&\|' option and specifying a file
name is that `\|\c
.B \-l\c
\&\|' surrounds
.I library
with `\|\c
.B lib\c
\&\|' and `\|\c
.B .a\c
\&\|' and searches several directories.
.TP
.B \-lobjc
You need this special case of the
.B \-l
option in order to link an Objective C program.
.TP
.B \-nostartfiles
Do not use the standard system startup files when linking.
The standard libraries are used normally.
.TP
.B \-nostdlib
Don't use the standard system libraries and startup files when linking.
Only the files you specify will be passed to the linker.
.TP
.B \-static
On systems that support dynamic linking, this prevents linking with the shared
libraries.  On other systems, this option has no effect.
.TP
.B \-shared
Produce a shared object which can then be linked with other objects to
form an executable.  Only a few systems support this option.
.TP
.B \-symbolic
Bind references to global symbols when building a shared object.  Warn
about any unresolved references (unless overridden by the link editor
option `\|\c
.B
\-Xlinker \-z \-Xlinker defs\c
\&\|').  Only a few systems support
this option.
.TP
.BI "\-Xlinker " "option"
Pass \c
.I option
as an option to the linker.  You can use this to
supply system-specific linker options which GNU CC does not know how to
recognize.
.Sp
If you want to pass an option that takes an argument, you must use
`\|\c
.B \-Xlinker\c
\&\|' twice, once for the option and once for the argument.
For example, to pass `\|\c
.B
\-assert definitions\c
\&\|', you must write
`\|\c
.B
\-Xlinker \-assert \-Xlinker definitions\c
\&\|'.  It does not work to write
`\|\c
.B
\-Xlinker "\-assert definitions"\c
\&\|', because this passes the entire
string as a single argument, which is not what the linker expects.
.TP
.BI "\-Wl," "option"
Pass \c
.I option\c
\& as an option to the linker.  If \c
.I option\c
\& contains
commas, it is split into multiple options at the commas.
.TP
.BI "\-u " "symbol"
Pretend the symbol
.I symbol
is undefined, to force linking of
library modules to define it.  You can use `\|\c
.B \-u\c
\&\|' multiple times with
different symbols to force loading of additional library modules.
.SH DIRECTORY OPTIONS
These options specify directories to search for header files, for
libraries and for parts of the compiler:
.TP
.BI "\-I" "dir"
Append directory \c
.I dir\c
\& to the list of directories searched for include files.
.TP
.B \-I\-
Any directories you specify with `\|\c
.B \-I\c
\&\|' options before the `\|\c
.B \-I\-\c
\&\|'
option are searched only for the case of `\|\c
.B
#include "\c
.I file\c
.B
\&"\c
\&\|';
they are not searched for `\|\c
.B #include <\c
.I file\c
\&>\c
\&\|'.
.Sp
If additional directories are specified with `\|\c
.B \-I\c
\&\|' options after
the `\|\c
.B \-I\-\c
\&\|', these directories are searched for all `\|\c
.B #include\c
\&\|'
directives.  (Ordinarily \c
.I all\c
\& `\|\c
.B \-I\c
\&\|' directories are used
this way.)
.Sp
In addition, the `\|\c
.B \-I\-\c
\&\|' option inhibits the use of the current
directory (where the current input file came from) as the first search
directory for `\|\c
.B
#include "\c
.I file\c
.B
\&"\c
\&\|'.  There is no way to
override this effect of `\|\c
.B \-I\-\c
\&\|'.  With `\|\c
.B \-I.\c
\&\|' you can specify
searching the directory which was current when the compiler was
invoked.  That is not exactly the same as what the preprocessor does
by default, but it is often satisfactory.
.Sp
`\|\c
.B \-I\-\c
\&\|' does not inhibit the use of the standard system directories
for header files.  Thus, `\|\c
.B \-I\-\c
\&\|' and `\|\c
.B \-nostdinc\c
\&\|' are
independent.
.TP
.BI "\-L" "dir"
Add directory \c
.I dir\c
\& to the list of directories to be searched
for `\|\c
.B \-l\c
\&\|'.
.TP
.BI "\-B" "prefix"
This option specifies where to find the executables, libraries and
data files of the compiler itself.
.Sp
The compiler driver program runs one or more of the subprograms
`\|\c
.B cpp\c
\&\|', `\|\c
.B cc1\c
\&\|' (or, for C++, `\|\c
.B cc1plus\c
\&\|'), `\|\c
.B as\c
\&\|' and `\|\c
.B ld\c
\&\|'.  It tries
.I prefix\c
\& as a prefix for each program it tries to run, both with and
without `\|\c
.I machine\c
.B /\c
.I version\c
.B /\c
\&\|'.
.Sp
For each subprogram to be run, the compiler driver first tries the
`\|\c
.B \-B\c
\&\|' prefix, if any.  If that name is not found, or if `\|\c
.B \-B\c
\&\|'
was not specified, the driver tries two standard prefixes, which are
`\|\c
.B /usr/lib/gcc/\c
\&\|' and `\|\c
.B /usr/local/lib/gcc-lib/\c
\&\|'.  If neither of
those results in a file name that is found, the compiler driver
searches for the unmodified program
name, using the directories specified in your
`\|\c
.B PATH\c
\&\|' environment variable.
.Sp
The run-time support file `\|\c
.B libgcc.a\c
\&\|' is also searched for using the
`\|\c
.B \-B\c
\&\|' prefix, if needed.  If it is not found there, the two
standard prefixes above are tried, and that is all.  The file is left
out of the link if it is not found by those means.  Most of the time,
on most machines, `\|\c
.B libgcc.a\c
\&\|' is not actually necessary.
.Sp
You can get a similar result from the environment variable
.B GCC_EXEC_PREFIX\c
\&; if it is defined, its value is used as a prefix
in the same way.  If both the `\|\c
.B \-B\c
\&\|' option and the
.B GCC_EXEC_PREFIX\c
\& variable are present, the `\|\c
.B \-B\c
\&\|' option is
used first and the environment variable value second.
.SH WARNING OPTIONS
Warnings are diagnostic messages that report constructions which
are not inherently erroneous but which are risky or suggest there
may have been an error.
.Sp
These options control the amount and kinds of warnings produced by GNU
CC:
.TP
.B \-fsyntax\-only
Check the code for syntax errors, but don't emit any output.
.TP
.B \-w
Inhibit all warning messages.
.TP
.B \-Wno\-import
Inhibit warning messages about the use of
.BR #import .
.TP
.B \-pedantic
Issue all the warnings demanded by strict ANSI standard C; reject
all programs that use forbidden extensions.
.Sp
Valid ANSI standard C programs should compile properly with or without
this option (though a rare few will require `\|\c
.B \-ansi\c
\&\|').  However,
without this option, certain GNU extensions and traditional C features
are supported as well.  With this option, they are rejected.  There is
no reason to \c
.I use\c
\& this option; it exists only to satisfy pedants.
.Sp
`\|\c
.B \-pedantic\c
\&\|' does not cause warning messages for use of the
alternate keywords whose names begin and end with `\|\c
.B _\|_\c
\&\|'.  Pedantic
warnings are also disabled in the expression that follows
.B _\|_extension_\|_\c
\&.  However, only system header files should use
these escape routes; application programs should avoid them.
.TP
.B \-pedantic\-errors
Like `\|\c
.B \-pedantic\c
\&\|', except that errors are produced rather than
warnings.
.TP
.B \-W
Print extra warning messages for these events:
.TP
\ \ \ \(bu
A nonvolatile automatic variable might be changed by a call to
.B longjmp\c
\&.  These warnings are possible only in
optimizing compilation.
.Sp
The compiler sees only the calls to \c
.B setjmp\c
\&.  It cannot know
where \c
.B longjmp\c
\& will be called; in fact, a signal handler could
call it at any point in the code.  As a result, you may get a warning
even when there is in fact no problem because \c
.B longjmp\c
\& cannot
in fact be called at the place which would cause a problem.
.TP
\ \ \ \(bu
A function can return either with or without a value.  (Falling
off the end of the function body is considered returning without
a value.)  For example, this function would evoke such a
warning:
.Sp
.nf
foo (a)
{
  if (a > 0)
    return a;
}
.Sp
.fi
Spurious warnings can occur because GNU CC does not realize that
certain functions (including \c
.B abort\c
\& and \c
.B longjmp\c
\&)
will never return.
.TP
\ \ \ \(bu
An expression-statement or the left-hand side of a comma expression
contains no side effects. 
To suppress the warning, cast the unused expression to void.
For example, an expression such as `\|\c
.B x[i,j]\c
\&\|' will cause a warning,
but `\|\c
.B x[(void)i,j]\c
\&\|' will not.
.TP
\ \ \ \(bu
An unsigned value is compared against zero with `\|\c
.B >\c
\&\|' or `\|\c
.B <=\c
\&\|'.
.PP
.TP
.B \-Wimplicit-int
Warn whenever a declaration does not specify a type.
.TP
.B \-Wimplicit-function-declaration
Warn whenever a function is used before being declared.
.TP
.B \-Wimplicit
Same as -Wimplicit-int and -Wimplicit-function-declaration.
.TP
.B \-Wmain
Warn if the
.B main
function is declared or defined with a suspicious type.
Typically, it is a function with external linkage, returning
.B int\c
\&, and
taking zero or two arguments.

.TP
.B \-Wreturn\-type
Warn whenever a function is defined with a return-type that defaults
to \c
.B int\c
\&.  Also warn about any \c
.B return\c
\& statement with no
return-value in a function whose return-type is not \c
.B void\c
\&.
.TP
.B \-Wunused
Warn whenever a local variable is unused aside from its declaration,
whenever a function is declared static but never defined, and whenever
a statement computes a result that is explicitly not used.
.TP
.B \-Wswitch
Warn whenever a \c
.B switch\c
\& statement has an index of enumeral type
and lacks a \c
.B case\c
\& for one or more of the named codes of that
enumeration.  (The presence of a \c
.B default\c
\& label prevents this
warning.)  \c
.B case\c
\& labels outside the enumeration range also
provoke warnings when this option is used.
.TP
.B \-Wcomment
Warn whenever a comment-start sequence `\|\c
.B /\(**\c
\&\|' appears in a comment.
.TP
.B \-Wtrigraphs
Warn if any trigraphs are encountered (assuming they are enabled).
.TP
.B \-Wformat
Check calls to \c
.B printf\c
\& and \c
.B scanf\c
\&, etc., to make sure that
the arguments supplied have types appropriate to the format string
specified.
.TP
.B \-Wchar\-subscripts
Warn if an array subscript has type
.BR char .
This is a common cause of error, as programmers often forget that this
type is signed on some machines.
.TP
.B \-Wuninitialized
An automatic variable is used without first being initialized.
.Sp
These warnings are possible only in optimizing compilation,
because they require data flow information that is computed only
when optimizing.  If you don't specify `\|\c
.B \-O\c
\&\|', you simply won't
get these warnings.
.Sp
These warnings occur only for variables that are candidates for
register allocation.  Therefore, they do not occur for a variable that
is declared \c
.B volatile\c
\&, or whose address is taken, or whose size
is other than 1, 2, 4 or 8 bytes.  Also, they do not occur for
structures, unions or arrays, even when they are in registers.
.Sp
Note that there may be no warning about a variable that is used only
to compute a value that itself is never used, because such
computations may be deleted by data flow analysis before the warnings
are printed.
.Sp
These warnings are made optional because GNU CC is not smart
enough to see all the reasons why the code might be correct
despite appearing to have an error.  Here is one example of how
this can happen:
.Sp
.nf
{
  int x;
  switch (y)
    {
    case 1: x = 1;
      break;
    case 2: x = 4;
      break;
    case 3: x = 5;
    }
  foo (x);
}
.Sp
.fi
If the value of \c
.B y\c
\& is always 1, 2 or 3, then \c
.B x\c
\& is
always initialized, but GNU CC doesn't know this.  Here is
another common case:
.Sp
.nf
{
  int save_y;
  if (change_y) save_y = y, y = new_y;
  .\|.\|.
  if (change_y) y = save_y;
}
.Sp
.fi
This has no bug because \c
.B save_y\c
\& is used only if it is set.
.Sp
Some spurious warnings can be avoided if you declare as
.B volatile\c
\& all the functions you use that never return.
.TP
.B \-Wparentheses
Warn if parentheses are omitted in certain contexts.
.TP
.B \-Wtemplate\-debugging
When using templates in a C++ program, warn if debugging is not yet
fully available (C++ only).
.TP
.B \-Wall
All of the above `\|\c
.B \-W\c
\&\|' options combined.  These are all the
options which pertain to usage that we recommend avoiding and that we
believe is easy to avoid, even in conjunction with macros.
.PP
The remaining `\|\c
.B \-W.\|.\|.\c
\&\|' options are not implied by `\|\c
.B \-Wall\c
\&\|'
because they warn about constructions that we consider reasonable to
use, on occasion, in clean programs.
.TP
.B \-Wtraditional
Warn about certain constructs that behave differently in traditional and
ANSI C.
.TP
\ \ \ \(bu
Macro arguments occurring within string constants in the macro body.
These would substitute the argument in traditional C, but are part of
the constant in ANSI C.
.TP
\ \ \ \(bu
A function declared external in one block and then used after the end of
the block.
.TP
\ \ \ \(bu
A \c
.B switch\c
\& statement has an operand of type \c
.B long\c
\&.
.PP
.TP
.B \-Wshadow
Warn whenever a local variable shadows another local variable.
.TP
.BI "\-Wid\-clash\-" "len"
Warn whenever two distinct identifiers match in the first \c
.I len
characters.  This may help you prepare a program that will compile
with certain obsolete, brain-damaged compilers.
.TP
.B \-Wpointer\-arith
Warn about anything that depends on the \*(lqsize of\*(rq a function type or
of \c
.B void\c
\&.  GNU C assigns these types a size of 1, for
convenience in calculations with \c
.B void \(**\c
\& pointers and pointers
to functions.
.TP
.B \-Wcast\-qual
Warn whenever a pointer is cast so as to remove a type qualifier from
the target type.  For example, warn if a \c
.B const char \(**\c
\& is cast
to an ordinary \c
.B char \(**\c
\&.
.TP
.B \-Wcast\-align
Warn whenever a pointer is cast such that the required alignment of the
target is increased.  For example, warn if a \c
.B char \(**\c
\& is cast to
an \c
.B int \(**\c
\& on machines where integers can only be accessed at
two- or four-byte boundaries.
.TP
.B \-Wwrite\-strings
Give string constants the type \c
.B const char[\c
.I length\c
.B ]\c
\& so that
copying the address of one into a non-\c
.B const\c
\& \c
.B char \(**
pointer will get a warning.  These warnings will help you find at
compile time code that can try to write into a string constant, but
only if you have been very careful about using \c
.B const\c
\& in
declarations and prototypes.  Otherwise, it will just be a nuisance;
this is why we did not make `\|\c
.B \-Wall\c
\&\|' request these warnings.
.TP
.B \-Wconversion
Warn if a prototype causes a type conversion that is different from what
would happen to the same argument in the absence of a prototype.  This
includes conversions of fixed point to floating and vice versa, and
conversions changing the width or signedness of a fixed point argument
except when the same as the default promotion.
.TP
.B \-Waggregate\-return
Warn if any functions that return structures or unions are defined or
called.  (In languages where you can return an array, this also elicits
a warning.)
.TP
.B \-Wstrict\-prototypes
Warn if a function is declared or defined without specifying the
argument types.  (An old-style function definition is permitted without
a warning if preceded by a declaration which specifies the argument
types.)
.TP
.B \-Wmissing\-prototypes
Warn if a global function is defined without a previous prototype
declaration.  This warning is issued even if the definition itself
provides a prototype.  The aim is to detect global functions that fail
to be declared in header files.
.TP
.B \-Wmissing\-declarations
Warn if a global function is defined without a previous declaration.
Do so even if the definition itself provides a prototype.
Use this option to detect global functions that are not declared in
header files.
.TP
.B \-Wredundant-decls
Warn if anything is declared more than once in the same scope, even in
cases where multiple declaration is valid and changes nothing.
.TP
.B \-Wnested-externs
Warn if an \c
.B extern\c
\& declaration is encountered within an function.
.TP
.B \-Wenum\-clash
Warn about conversion between different enumeration types (C++ only).
.TP
.B \-Wlong-long
Warn if
.B long long \c
type is used.  This is default.  To inhibit
the warning messages, use flag `\|\c
.B \-Wno\-long\-long\c
\&\|'.  Flags `\|\c
.B \-W\-long\-long\c
\&\|' and `\|\c
.B \-Wno\-long\-long\c
\&\|' are taken into account only when flag `\|\c
.B \-pedantic\c
\&\|' is used.
.TP
.B \-Woverloaded\-virtual
(C++ only.)
In a derived class, the definitions of virtual functions must match
the type signature of a virtual function declared in the base class.
Use this option to request warnings when a derived class declares a
function that may be an erroneous attempt to define a virtual
function: that is, warn when a function with the same name as a
virtual function in the base class, but with a type signature that
doesn't match any virtual functions from the base class.
.TP
.B \-Winline
Warn if a function can not be inlined, and either it was declared as inline,
or else the
.B \-finline\-functions
option was given.
.TP
.B \-Werror
Treat warnings as errors; abort compilation after any warning.
.SH DEBUGGING OPTIONS
GNU CC has various special options that are used for debugging
either your program or GCC:
.TP
.B \-g
Produce debugging information in the operating system's native format
(stabs, COFF, XCOFF, or DWARF).  GDB can work with this debugging
information.
.Sp
On most systems that use stabs format, `\|\c
.B \-g\c
\&\|' enables use of extra
debugging information that only GDB can use; this extra information
makes debugging work better in GDB but will probably make other debuggers
crash or
refuse to read the program.  If you want to control for certain whether
to generate the extra information, use `\|\c
.B \-gstabs+\c
\&\|', `\|\c
.B \-gstabs\c
\&\|',
`\|\c
.B \-gxcoff+\c
\&\|', `\|\c
.B \-gxcoff\c
\&\|', `\|\c
.B \-gdwarf+\c
\&\|', or `\|\c
.B \-gdwarf\c
\&\|'
(see below).
.Sp
Unlike most other C compilers, GNU CC allows you to use `\|\c
.B \-g\c
\&\|' with
`\|\c
.B \-O\c
\&\|'.  The shortcuts taken by optimized code may occasionally
produce surprising results: some variables you declared may not exist
at all; flow of control may briefly move where you did not expect it;
some statements may not be executed because they compute constant
results or their values were already at hand; some statements may
execute in different places because they were moved out of loops.
.Sp
Nevertheless it proves possible to debug optimized output.  This makes
it reasonable to use the optimizer for programs that might have bugs.
.PP
The following options are useful when GNU CC is generated with the
capability for more than one debugging format.
.TP
.B \-ggdb
Produce debugging information in the native format (if that is supported),
including GDB extensions if at all possible.
.TP
.B \-gstabs
Produce debugging information in stabs format (if that is supported),
without GDB extensions.  This is the format used by DBX on most BSD
systems.
.TP
.B \-gstabs+
Produce debugging information in stabs format (if that is supported),
using GNU extensions understood only by the GNU debugger (GDB).  The
use of these extensions is likely to make other debuggers crash or
refuse to read the program.
.TP
.B \-gcoff
Produce debugging information in COFF format (if that is supported).
This is the format used by SDB on most System V systems prior to
System V Release 4.
.TP
.B \-gxcoff
Produce debugging information in XCOFF format (if that is supported).
This is the format used by the DBX debugger on IBM RS/6000 systems.
.TP
.B \-gxcoff+
Produce debugging information in XCOFF format (if that is supported),
using GNU extensions understood only by the GNU debugger (GDB).  The
use of these extensions is likely to make other debuggers crash or
refuse to read the program.
.TP
.B \-gdwarf
Produce debugging information in DWARF format (if that is supported).
This is the format used by SDB on most System V Release 4 systems.
.TP
.B \-gdwarf+
Produce debugging information in DWARF format (if that is supported),
using GNU extensions understood only by the GNU debugger (GDB).  The
use of these extensions is likely to make other debuggers crash or
refuse to read the program.
.PP
.BI "\-g" "level"
.br
.BI "\-ggdb" "level"
.br
.BI "\-gstabs" "level"
.br
.BI "\-gcoff" "level"
.BI "\-gxcoff" "level"
.TP
.BI "\-gdwarf" "level"
Request debugging information and also use \c
.I level\c
\& to specify how
much information.  The default level is 2.
.Sp
Level 1 produces minimal information, enough for making backtraces in
parts of the program that you don't plan to debug.  This includes
descriptions of functions and external variables, but no information
about local variables and no line numbers.
.Sp
Level 3 includes extra information, such as all the macro definitions
present in the program.  Some debuggers support macro expansion when
you use `\|\c
.B \-g3\c
\&\|'.
.TP
.B \-p
Generate extra code to write profile information suitable for the
analysis program \c
.B prof\c
\&.
.TP
.B \-pg
Generate extra code to write profile information suitable for the
analysis program \c
.B gprof\c
\&.
.TP
.B \-a
Generate extra code to write profile information for basic blocks,
which will record the number of times each basic block is executed.
This data could be analyzed by a program like \c
.B tcov\c
\&.  Note,
however, that the format of the data is not what \c
.B tcov\c
\& expects.
Eventually GNU \c
.B gprof\c
\& should be extended to process this data.
.TP
.B \-ax
Generate extra code to read basic block profiling parameters from 
file `bb.in' and write profiling results to file `bb.out'.
`bb.in' contains a list of functions. Whenever a function on the list
is entered, profiling is turned on. When the outmost function is left,
profiling is turned off. If a function name is prefixed with `-'
the function is excluded from profiling. If a function name is not
unique it can be disambiguated by writing
`/path/filename.d:functionname'. `bb.out' will list some available
filenames.
Four function names have a special meaning:
`__bb_jumps__' will cause jump frequencies to be written to `bb.out'.
`__bb_trace__' will cause the sequence of basic blocks to be piped 
into `gzip' and written to file `bbtrace.gz'.
`__bb_hidecall__' will cause call instructions to be excluded from
the trace.
`__bb_showret__' will cause return instructions to be included in
the trace.
.TP
.BI "\-d" "letters"
Says to make debugging dumps during compilation at times specified by
.I letters\c
\&.  This is used for debugging the compiler.  The file names
for most of the dumps are made by appending a word to the source file
name (e.g.  `\|\c
.B foo.c.rtl\c
\&\|' or `\|\c
.B foo.c.jump\c
\&\|').
.TP
.B \-dM
Dump all macro definitions, at the end of preprocessing, and write no
output.
.TP
.B \-dN
Dump all macro names, at the end of preprocessing.
.TP
.B \-dD
Dump all macro definitions, at the end of preprocessing, in addition to
normal output.
.TP
.B \-dy
Dump debugging information during parsing, to standard error.
.TP
.B \-dr
Dump after RTL generation, to `\|\c
.I file\c
.B \&.rtl\c
\&\|'.
.TP
.B \-dx
Just generate RTL for a function instead of compiling it.  Usually used
with `\|\c
.B r\c
\&\|'.
.TP
.B \-dj
Dump after first jump optimization, to `\|\c
.I file\c
.B \&.jump\c
\&\|'.
.TP
.B \-ds
Dump after CSE (including the jump optimization that sometimes
follows CSE), to `\|\c
.I file\c
.B \&.cse\c
\&\|'.
.TP
.B \-dL
Dump after loop optimization, to `\|\c
.I file\c
.B \&.loop\c
\&\|'.
.TP
.B \-dt
Dump after the second CSE pass (including the jump optimization that
sometimes follows CSE), to `\|\c
.I file\c
.B \&.cse2\c
\&\|'.
.TP
.B \-df
Dump after flow analysis, to `\|\c
.I file\c
.B \&.flow\c
\&\|'.
.TP
.B \-dc
Dump after instruction combination, to `\|\c
.I file\c
.B \&.combine\c
\&\|'.
.TP
.B \-dS
Dump after the first instruction scheduling pass, to
`\|\c
.I file\c
.B \&.sched\c
\&\|'.
.TP
.B \-dl
Dump after local register allocation, to `\|\c
.I file\c
.B \&.lreg\c
\&\|'.
.TP
.B \-dg
Dump after global register allocation, to `\|\c
.I file\c
.B \&.greg\c
\&\|'.
.TP
.B \-dR
Dump after the second instruction scheduling pass, to
`\|\c
.I file\c
.B \&.sched2\c
\&\|'.
.TP
.B \-dJ
Dump after last jump optimization, to `\|\c
.I file\c
.B \&.jump2\c
\&\|'.
.TP
.B \-dd
Dump after delayed branch scheduling, to `\|\c
.I file\c
.B \&.dbr\c
\&\|'.
.TP
.B \-dk
Dump after conversion from registers to stack, to `\|\c
.I file\c
.B \&.stack\c
\&\|'.
.TP
.B \-da
Produce all the dumps listed above.
.TP
.B \-dm
Print statistics on memory usage, at the end of the run, to
standard error.
.TP
.B \-dp
Annotate the assembler output with a comment indicating which
pattern and alternative was used.
.TP
.B \-fpretend\-float
When running a cross-compiler, pretend that the target machine uses the
same floating point format as the host machine.  This causes incorrect
output of the actual floating constants, but the actual instruction
sequence will probably be the same as GNU CC would make when running on
the target machine.
.TP
.B \-save\-temps
Store the usual \*(lqtemporary\*(rq intermediate files permanently; place them
in the current directory and name them based on the source file.  Thus,
compiling `\|\c
.B foo.c\c
\&\|' with `\|\c
.B \-c \-save\-temps\c
\&\|' would produce files
`\|\c
.B foo.cpp\c
\&\|' and `\|\c
.B foo.s\c
\&\|', as well as `\|\c
.B foo.o\c
\&\|'.
.TP
.BI "\-print\-file\-name=" "library"
Print the full absolute name of the library file \|\c
.nh
.I library
.hy
\&\| that
would be used when linking\(em\&and do not do anything else.  With this
option, GNU CC does not compile or link anything; it just prints the
file name.
.TP
.B \-print\-libgcc\-file\-name
Same as `\|\c
.B \-print\-file\-name=libgcc.a\c
\&\|'.
.TP
.BI "\-print\-prog\-name=" "program"
Like `\|\c
.B \-print\-file\-name\c
\&\|', but searches for a program such as `\|\c
cpp\c
\&\|'.
.SH OPTIMIZATION OPTIONS
These options control various sorts of optimizations:
.TP
.B \-O
.TP
.B \-O1
Optimize.  Optimizing compilation takes somewhat more time, and a lot
more memory for a large function.
.Sp
Without `\|\c
.B \-O\c
\&\|', the compiler's goal is to reduce the cost of
compilation and to make debugging produce the expected results.
Statements are independent: if you stop the program with a breakpoint
between statements, you can then assign a new value to any variable or
change the program counter to any other statement in the function and
get exactly the results you would expect from the source code.
.Sp
Without `\|\c
.B \-O\c
\&\|', only variables declared \c
.B register\c
\& are
allocated in registers.  The resulting compiled code is a little worse
than produced by PCC without `\|\c
.B \-O\c
\&\|'.
.Sp
With `\|\c
.B \-O\c
\&\|', the compiler tries to reduce code size and execution
time.
.Sp
When you specify `\|\c
.B \-O\c
\&\|', the two options `\|\c
.B \-fthread\-jumps\c
\&\|' and `\|\c
.B \-fdefer\-pop\c
\&\|' are turned on.  On machines that have delay slots, the `\|\c
.B \-fdelayed\-branch\c
\&\|' option is turned on.  For those machines that can support debugging even
without a frame pointer, the `\|\c
.B \-fomit\-frame\-pointer\c
\&\|' option is turned on.  On some machines other flags may also be turned on.
.TP
.B \-O2
Optimize even more.  Nearly all supported optimizations that do not
involve a space-speed tradeoff are performed.  Loop unrolling and function
inlining are not done, for example.  As compared to
.B \-O\c
\&,
this option increases both compilation time and the performance of the
generated code.
.TP
.B \-O3
Optimize yet more. This turns on everything
.B \-O2
does, along with also turning on
.B \-finline\-functions.
.TP
.B \-O0
Do not optimize.
.Sp
If you use multiple
.B \-O
options, with or without level numbers, the last such option is the
one that is effective.
.PP
Options of the form `\|\c
.B \-f\c
.I flag\c
\&\c
\&\|' specify machine-independent
flags.  Most flags have both positive and negative forms; the negative
form of `\|\c
.B \-ffoo\c
\&\|' would be `\|\c
.B \-fno\-foo\c
\&\|'.  The following list shows
only one form\(em\&the one which is not the default.
You can figure out the other form by either removing `\|\c
.B no\-\c
\&\|' or
adding it.
.TP
.B \-ffloat\-store
Do not store floating point variables in registers.  This
prevents undesirable excess precision on machines such as the
68000 where the floating registers (of the 68881) keep more
precision than a \c
.B double\c
\& is supposed to have.
.Sp
For most programs, the excess precision does only good, but a few
programs rely on the precise definition of IEEE floating point.
Use `\|\c
.B \-ffloat\-store\c
\&\|' for such programs.
.TP
.B \-fmemoize\-lookups
.TP
.B \-fsave\-memoized
Use heuristics to compile faster (C++ only).  These heuristics are not
enabled by default, since they are only effective for certain input
files.  Other input files compile more slowly.
.Sp
The first time the compiler must build a call to a member function (or
reference to a data member), it must (1) determine whether the class
implements member functions of that name; (2) resolve which member
function to call (which involves figuring out what sorts of type
conversions need to be made); and (3) check the visibility of the member
function to the caller.  All of this adds up to slower compilation.
Normally, the second time a call is made to that member function (or
reference to that data member), it must go through the same lengthy
process again.  This means that code like this
.Sp
\&  cout << "This " << p << " has " << n << " legs.\en";
.Sp
makes six passes through all three steps.  By using a software cache,
a \*(lqhit\*(rq significantly reduces this cost.  Unfortunately, using the
cache introduces another layer of mechanisms which must be implemented,
and so incurs its own overhead.  `\|\c
.B \-fmemoize\-lookups\c
\&\|' enables
the software cache.
.Sp
Because access privileges (visibility) to members and member functions
may differ from one function context to the next,
.B g++
may need to flush the cache.  With the `\|\c
.B \-fmemoize\-lookups\c
\&\|' flag, the cache is flushed after every
function that is compiled.  The `\|\c
\-fsave\-memoized\c
\&\|' flag enables the same software cache, but when the compiler
determines that the context of the last function compiled would yield
the same access privileges of the next function to compile, it
preserves the cache.
This is most helpful when defining many member functions for the same
class: with the exception of member functions which are friends of
other classes, each member function has exactly the same access
privileges as every other, and the cache need not be flushed.
.TP
.B \-fno\-default\-inline
Don't make member functions inline by default merely because they are
defined inside the class scope (C++ only).
.TP
.B \-fno\-defer\-pop
Always pop the arguments to each function call as soon as that
function returns.  For machines which must pop arguments after a
function call, the compiler normally lets arguments accumulate on the
stack for several function calls and pops them all at once.
.TP
.B \-fforce\-mem
Force memory operands to be copied into registers before doing
arithmetic on them.  This may produce better code by making all
memory references potential common subexpressions.  When they are
not common subexpressions, instruction combination should
eliminate the separate register-load.  I am interested in hearing
about the difference this makes.
.TP
.B \-fforce\-addr
Force memory address constants to be copied into registers before
doing arithmetic on them.  This may produce better code just as
`\|\c
.B \-fforce\-mem\c
\&\|' may.  I am interested in hearing about the
difference this makes.
.TP
.B \-fomit\-frame\-pointer
Don't keep the frame pointer in a register for functions that
don't need one.  This avoids the instructions to save, set up and
restore frame pointers; it also makes an extra register available
in many functions.  \c
.I It also makes debugging impossible on most machines\c
\&.
.Sp
On some machines, such as the Vax, this flag has no effect, because
the standard calling sequence automatically handles the frame pointer
and nothing is saved by pretending it doesn't exist.  The
machine-description macro \c
.B FRAME_POINTER_REQUIRED\c
\& controls
whether a target machine supports this flag.
.TP
.B \-finline\-functions
Integrate all simple functions into their callers.  The compiler
heuristically decides which functions are simple enough to be worth
integrating in this way.
.Sp
If all calls to a given function are integrated, and the function is
declared \c
.B static\c
\&, then GCC normally does not output the function as
assembler code in its own right.
.TP
.B \-fcaller\-saves
Enable values to be allocated in registers that will be clobbered by
function calls, by emitting extra instructions to save and restore the
registers around such calls.  Such allocation is done only when it
seems to result in better code than would otherwise be produced.
.Sp
This option is enabled by default on certain machines, usually those
which have no call-preserved registers to use instead.
.TP
.B \-fkeep\-inline\-functions
Even if all calls to a given function are integrated, and the function
is declared \c
.B static\c
\&, nevertheless output a separate run-time
callable version of the function.
.TP
.B \-fno\-function\-cse
Do not put function addresses in registers; make each instruction that
calls a constant function contain the function's address explicitly.
.Sp
This option results in less efficient code, but some strange hacks
that alter the assembler output may be confused by the optimizations
performed when this option is not used.
.TP
.B \-fno\-peephole
Disable any machine-specific peephole optimizations.
.TP
.B \-ffast-math
This option allows GCC to violate some ANSI or IEEE rules/specifications
in the interest of optimizing code for speed.  For example, it allows
the compiler to assume arguments to the \c
.B sqrt\c
\& function are
non-negative numbers.
.Sp
This option should never be turned on by any `\|\c
.B \-O\c
\&\|' option since
it can result in incorrect output for programs which depend on
an exact implementation of IEEE or ANSI rules/specifications for
math functions.
.PP
The following options control specific optimizations.  The `\|\c
.B \-O2\c
\&\|'
option turns on all of these optimizations except `\|\c
.B \-funroll\-loops\c
\&\|'
and `\|\c
.B \-funroll\-all\-loops\c
\&\|'.
.PP
The `\|\c
.B \-O\c
\&\|' option usually turns on
the `\|\c
.B \-fthread\-jumps\c
\&\|' and `\|\c
.B \-fdelayed\-branch\c
\&\|' options, but
specific machines may change the default optimizations.
.PP
You can use the following flags in the rare cases when \*(lqfine-tuning\*(rq
of optimizations to be performed is desired.
.TP
.B \-fstrength\-reduce
Perform the optimizations of loop strength reduction and
elimination of iteration variables.
.TP
.B \-fthread\-jumps
Perform optimizations where we check to see if a jump branches to a
location where another comparison subsumed by the first is found.  If
so, the first branch is redirected to either the destination of the
second branch or a point immediately following it, depending on whether
the condition is known to be true or false.
.TP
.B \-funroll\-loops
Perform the optimization of loop unrolling.  This is only done for loops
whose number of iterations can be determined at compile time or run time.
.TP
.B \-funroll\-all\-loops
Perform the optimization of loop unrolling.  This is done for all loops.
This usually makes programs run more slowly.
.TP
.B \-fcse\-follow\-jumps
In common subexpression elimination, scan through jump instructions
when the target of the jump is not reached by any other path.  For
example, when CSE encounters an \c
.B if\c
\& statement with an
.B else\c
\& clause, CSE will follow the jump when the condition
tested is false.
.TP
.B \-fcse\-skip\-blocks
This is similar to `\|\c
.B \-fcse\-follow\-jumps\c
\&\|', but causes CSE to
follow jumps which conditionally skip over blocks.  When CSE
encounters a simple \c
.B if\c
\& statement with no else clause,
`\|\c
.B \-fcse\-skip\-blocks\c
\&\|' causes CSE to follow the jump around the
body of the \c
.B if\c
\&.
.TP
.B \-frerun\-cse\-after\-loop
Re-run common subexpression elimination after loop optimizations has been
performed.
.TP
.B \-felide\-constructors
Elide constructors when this seems plausible (C++ only).  With this
flag, GNU C++ initializes \c
.B y\c
\& directly from the call to \c
.B foo
without going through a temporary in the following code:
.Sp
A foo ();
A y = foo ();
.Sp
Without this option, GNU C++ first initializes \c
.B y\c
\& by calling the
appropriate constructor for type \c
.B A\c
\&; then assigns the result of
.B foo\c
\& to a temporary; and, finally, replaces the initial value of
`\|\c
.B y\c
\&\|' with the temporary.
.Sp
The default behavior (`\|\c
.B \-fno\-elide\-constructors\c
\&\|') is specified by
the draft ANSI C++ standard.  If your program's constructors have side
effects, using `\|\c
.B \-felide-constructors\c
\&\|' can make your program act
differently, since some constructor calls may be omitted.
.TP
.B \-fexpensive\-optimizations
Perform a number of minor optimizations that are relatively expensive.
.TP
.B \-fdelayed\-branch
If supported for the target machine, attempt to reorder instructions
to exploit instruction slots available after delayed branch
instructions.
.TP
.B \-fschedule\-insns
If supported for the target machine, attempt to reorder instructions to
eliminate execution stalls due to required data being unavailable.  This
helps machines that have slow floating point or memory load instructions
by allowing other instructions to be issued until the result of the load
or floating point instruction is required.
.TP
.B \-fschedule\-insns2
Similar to `\|\c
.B \-fschedule\-insns\c
\&\|', but requests an additional pass of
instruction scheduling after register allocation has been done.  This is
especially useful on machines with a relatively small number of
registers and where memory load instructions take more than one cycle.
.SH TARGET OPTIONS
By default, GNU CC compiles code for the same type of machine that you
are using.  However, it can also be installed as a cross-compiler, to
compile for some other type of machine.  In fact, several different
configurations of GNU CC, for different target machines, can be
installed side by side.  Then you specify which one to use with the
`\|\c
.B \-b\c
\&\|' option.
.PP
In addition, older and newer versions of GNU CC can be installed side
by side.  One of them (probably the newest) will be the default, but
you may sometimes wish to use another.
.TP
.BI "\-b " "machine"
The argument \c
.I machine\c
\& specifies the target machine for compilation.
This is useful when you have installed GNU CC as a cross-compiler.
.Sp
The value to use for \c
.I machine\c
\& is the same as was specified as the
machine type when configuring GNU CC as a cross-compiler.  For
example, if a cross-compiler was configured with `\|\c
.B configure
i386v\c
\&\|', meaning to compile for an 80386 running System V, then you
would specify `\|\c
.B \-b i386v\c
\&\|' to run that cross compiler.
.Sp
When you do not specify `\|\c
.B \-b\c
\&\|', it normally means to compile for
the same type of machine that you are using.
.TP
.BI "\-V " "version"
The argument \c
.I version\c
\& specifies which version of GNU CC to run.
This is useful when multiple versions are installed.  For example,
.I version\c
\& might be `\|\c
.B 2.0\c
\&\|', meaning to run GNU CC version 2.0.
.Sp
The default version, when you do not specify `\|\c
.B \-V\c
\&\|', is controlled
by the way GNU CC is installed.  Normally, it will be a version that
is recommended for general use.
.SH MACHINE DEPENDENT OPTIONS
Each of the target machine types can have its own special options,
starting with `\|\c
.B \-m\c
\&\|', to choose among various hardware models or
configurations\(em\&for example, 68010 vs 68020, floating coprocessor or
none.  A single installed version of the compiler can compile for any
model or configuration, according to the options specified.
.PP
Some configurations of the compiler also support additional special
options, usually for command-line compatibility with other compilers on
the same platform.
.PP
These are the `\|\c
.B \-m\c
\&\|' options defined for the 68000 series:
.TP
.B \-m68000
.TP
.B \-mc68000
Generate output for a 68000.  This is the default when the compiler is
configured for 68000-based systems.
.TP
.B \-m68020
.TP
.B \-mc68020
Generate output for a 68020 (rather than a 68000).  This is the
default when the compiler is configured for 68020-based systems.
.TP
.B \-m68881
Generate output containing 68881 instructions for floating point.
This is the default for most 68020-based systems unless
.B \-nfp
was specified when the compiler was configured.
.TP
.B \-m68030
Generate output for a 68030.  This is the default when the compiler is
configured for 68030-based systems.
.TP
.B \-m68040
Generate output for a 68040.  This is the default when the compiler is
configured for 68040-based systems.
.TP
.B \-m68020\-40
Generate output for a 68040, without using any of the new instructions.
This results in code which can run relatively efficiently on either a
68020/68881 or a 68030 or a 68040.
.TP
.B \-mfpa
Generate output containing Sun FPA instructions for floating point.
.TP
.B \-msoft\-float
Generate output containing library calls for floating point.
.I
WARNING:
the requisite libraries are not part of GNU CC.  Normally the
facilities of the machine's usual C compiler are used, but this can't
be done directly in cross-compilation.  You must make your own
arrangements to provide suitable library functions for cross-compilation.
.TP
.B \-mshort
Consider type \c
.B int\c
\& to be 16 bits wide, like \c
.B short int\c
\&.
.TP
.B \-mnobitfield
Do not use the bit-field instructions.  `\|\c
.B \-m68000\c
\&\|' implies
`\|\c
.B \-mnobitfield\c
\&\|'.
.TP
.B \-mbitfield
Do use the bit-field instructions.  `\|\c
.B \-m68020\c
\&\|' implies
`\|\c
.B \-mbitfield\c
\&\|'.  This is the default if you use the unmodified
sources.
.TP
.B \-mrtd
Use a different function-calling convention, in which functions
that take a fixed number of arguments return with the \c
.B rtd
instruction, which pops their arguments while returning.  This
saves one instruction in the caller since there is no need to pop
the arguments there.
.Sp
This calling convention is incompatible with the one normally
used on Unix, so you cannot use it if you need to call libraries
compiled with the Unix compiler.
.Sp
Also, you must provide function prototypes for all functions that
take variable numbers of arguments (including \c
.B printf\c
\&);
otherwise incorrect code will be generated for calls to those
functions.
.Sp
In addition, seriously incorrect code will result if you call a
function with too many arguments.  (Normally, extra arguments are
harmlessly ignored.)
.Sp
The \c
.B rtd\c
\& instruction is supported by the 68010 and 68020
processors, but not by the 68000.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the Vax:
.TP
.B \-munix
Do not output certain jump instructions (\c
.B aobleq\c
\& and so on)
that the Unix assembler for the Vax cannot handle across long
ranges.
.TP
.B \-mgnu
Do output those jump instructions, on the assumption that you
will assemble with the GNU assembler.
.TP
.B \-mg
Output code for g-format floating point numbers instead of d-format.
.PP
These `\|\c
.B \-m\c
\&\|' switches are supported on the SPARC:
.PP
.B \-mfpu
.TP
.B \-mhard\-float
Generate output containing floating point instructions.  This is the
default.
.PP
.B \-mno\-fpu
.TP
.B \-msoft\-float
Generate output containing library calls for floating point.
.I Warning:
there is no GNU floating-point library for SPARC.
Normally the facilities of the machine's usual C compiler are used, but
this cannot be done directly in cross-compilation.  You must make your
own arrangements to provide suitable library functions for
cross-compilation.
.Sp
.B \-msoft\-float
changes the calling convention in the output file;
therefore, it is only useful if you compile
.I all
of a program with this option.
.PP
.B \-mno\-epilogue
.TP
.B \-mepilogue
With
.B \-mepilogue
(the default), the compiler always emits code for
function exit at the end of each function.  Any function exit in
the middle of the function (such as a return statement in C) will
generate a jump to the exit code at the end of the function.
.Sp
With
.BR \-mno\-epilogue ,
the compiler tries to emit exit code inline at every function exit.
.PP
.B \-mno\-v8
.TP
.B \-mv8
.TP
.B \-msparclite
These three options select variations on the SPARC architecture.
.Sp
By default (unless specifically configured for the Fujitsu SPARClite),
GCC generates code for the v7 variant of the SPARC architecture.
.Sp
.B \-mv8
will give you SPARC v8 code.  The only difference from v7
code is that the compiler emits the integer multiply and integer
divide instructions which exist in SPARC v8 but not in SPARC v7.
.Sp
.B \-msparclite
will give you SPARClite code.  This adds the integer
multiply, integer divide step and scan (ffs) instructions which
exist in SPARClite but not in SPARC v7.
.PP
.B \-mcypress
.TP
.B \-msupersparc
These two options select the processor for which the code is optimised.
.Sp
With
.B \-mcypress
(the default), the compiler optimises code for the Cypress CY7C602 chip, as
used in the SparcStation/SparcServer 3xx series. This is also appropriate for
the older SparcStation 1, 2, IPX etc.
.Sp
With
.B \-msupersparc
the compiler optimises code for the SuperSparc cpu, as used in the SparcStation
10, 1000 and 2000 series. This flag also enables use of the full SPARC v8
instruction set.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the Convex:
.TP
.B \-mc1
Generate output for a C1.  This is the default when the compiler is
configured for a C1.
.TP
.B \-mc2
Generate output for a C2.  This is the default when the compiler is
configured for a C2.
.TP
.B \-margcount
Generate code which puts an argument count in the word preceding each
argument list.  Some nonportable Convex and Vax programs need this word.
(Debuggers don't, except for functions with variable-length argument
lists; this info is in the symbol table.)
.TP
.B \-mnoargcount
Omit the argument count word.  This is the default if you use the
unmodified sources.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the AMD Am29000:
.TP
.B \-mdw
Generate code that assumes the DW bit is set, i.e., that byte and
halfword operations are directly supported by the hardware.  This is the
default.
.TP
.B \-mnodw
Generate code that assumes the DW bit is not set.
.TP
.B \-mbw
Generate code that assumes the system supports byte and halfword write
operations.  This is the default.
.TP
.B \-mnbw
Generate code that assumes the systems does not support byte and
halfword write operations.  This implies `\|\c
.B \-mnodw\c
\&\|'.
.TP
.B \-msmall
Use a small memory model that assumes that all function addresses are
either within a single 256 KB segment or at an absolute address of less
than 256K.  This allows the \c
.B call\c
\& instruction to be used instead
of a \c
.B const\c
\&, \c
.B consth\c
\&, \c
.B calli\c
\& sequence.
.TP
.B \-mlarge
Do not assume that the \c
.B call\c
\& instruction can be used; this is the
default.
.TP
.B \-m29050
Generate code for the Am29050.
.TP
.B \-m29000
Generate code for the Am29000.  This is the default.
.TP
.B \-mkernel\-registers
Generate references to registers \c
.B gr64-gr95\c
\& instead of
.B gr96-gr127\c
\&.  This option can be used when compiling kernel code
that wants a set of global registers disjoint from that used by
user-mode code.
.Sp
Note that when this option is used, register names in `\|\c
.B \-f\c
\&\|' flags
must use the normal, user-mode, names.
.TP
.B \-muser\-registers
Use the normal set of global registers, \c
.B gr96-gr127\c
\&.  This is the
default.
.TP
.B \-mstack\-check
Insert a call to \c
.B _\|_msp_check\c
\& after each stack adjustment.  This
is often used for kernel code.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for Motorola 88K architectures:
.TP
.B \-m88000
Generate code that works well on both the m88100 and the
m88110.
.TP
.B \-m88100
Generate code that works best for the m88100, but that also
runs on the m88110.
.TP
.B \-m88110
Generate code that works best for the m88110, and may not run
on the m88100.
.TP
.B \-midentify\-revision
Include an \c
.B ident\c
\& directive in the assembler output recording the
source file name, compiler name and version, timestamp, and compilation
flags used.
.TP
.B \-mno\-underscores
In assembler output, emit symbol names without adding an underscore
character at the beginning of each name.  The default is to use an
underscore as prefix on each name.
.TP
.B \-mno\-check\-zero\-division
.TP
.B \-mcheck\-zero\-division
Early models of the 88K architecture had problems with division by zero;
in particular, many of them didn't trap.  Use these options to avoid
including (or to include explicitly) additional code to detect division
by zero and signal an exception.  All GCC configurations for the 88K use
`\|\c
.B \-mcheck\-zero\-division\c
\&\|' by default.
.TP
.B \-mocs\-debug\-info
.TP
.B \-mno\-ocs\-debug\-info
Include (or omit) additional debugging information (about
registers used in each stack frame) as specified in the 88Open Object
Compatibility Standard, \*(lqOCS\*(rq.  This extra information is not needed
by GDB.  The default for DG/UX, SVr4, and Delta 88 SVr3.2 is to
include this information; other 88k configurations omit this information
by default.
.TP
.B \-mocs\-frame\-position
.TP
.B \-mno\-ocs\-frame\-position
Force (or do not require) register values to be stored in a particular
place in stack frames, as specified in OCS.  The DG/UX, Delta88 SVr3.2,
and BCS configurations use `\|\c
.B \-mocs\-frame\-position\c
\&\|'; other 88k
configurations have the default `\|\c
.B \-mno\-ocs\-frame\-position\c
\&\|'.
.TP
.B \-moptimize\-arg\-area
.TP
.B \-mno\-optimize\-arg\-area
Control how to store function arguments in stack frames.
`\|\c
.B \-moptimize\-arg\-area\c
\&\|' saves space, but may break some
debuggers (not GDB).  `\|\c
.B \-mno\-optimize\-arg\-area\c
\&\|' conforms better to
standards.   By default GCC does not optimize the argument area.
.TP
.BI "\-mshort\-data\-" "num"
.I num
Generate smaller data references by making them relative to \c
.B r0\c
\&,
which allows loading a value using a single instruction (rather than the
usual two).  You control which data references are affected by
specifying \c
.I num\c
\& with this option.  For example, if you specify
`\|\c
.B \-mshort\-data\-512\c
\&\|', then the data references affected are those
involving displacements of less than 512 bytes.
`\|\c
.B \-mshort\-data\-\c
.I num\c
\&\c
\&\|' is not effective for \c
.I num\c
\& greater
than 64K.
.PP
.B \-mserialize-volatile
.TP
.B \-mno-serialize-volatile
Do, or do not, generate code to guarantee sequential consistency of
volatile memory references.
.Sp
GNU CC always guarantees consistency by default, for the preferred
processor submodel.  How this is done depends on the submodel.
.Sp
The m88100 processor does not reorder memory references and so always
provides sequential consistency.  If you use `\|\c
.B \-m88100\c
\&\|', GNU CC does
not generate any special instructions for sequential consistency.
.Sp
The order of memory references made by the m88110 processor does not
always match the order of the instructions requesting those references.
In particular, a load instruction may execute before a preceding store
instruction.  Such reordering violates sequential consistency of
volatile memory references, when there are multiple processors.  When
you use `\|\c
.B \-m88000\c
\&\|' or `\|\c
.B \-m88110\c
\&\|', GNU CC generates special
instructions when appropriate, to force execution in the proper order.
.Sp
The extra code generated to guarantee consistency may affect the
performance of your application.  If you know that you can safely forgo
this guarantee, you may use the option `\|\c
.B \-mno-serialize-volatile\c
\&\|'.
.Sp
If you use the `\|\c
.B \-m88100\c
\&\|' option but require sequential consistency
when running on the m88110 processor, you should use
`\|\c
.B \-mserialize-volatile\c
\&\|'.
.PP
.B \-msvr4
.TP
.B \-msvr3
Turn on (`\|\c
.B \-msvr4\c
\&\|') or off (`\|\c
.B \-msvr3\c
\&\|') compiler extensions
related to System V release 4 (SVr4).  This controls the following:
.TP
\ \ \ \(bu
Which variant of the assembler syntax to emit (which you can select
independently using `\|\c
.B \-mversion\-03.00\c
\&\|').
.TP
\ \ \ \(bu
`\|\c
.B \-msvr4\c
\&\|' makes the C preprocessor recognize `\|\c
.B #pragma weak\c
\&\|'
.TP
\ \ \ \(bu
`\|\c
.B \-msvr4\c
\&\|' makes GCC issue additional declaration directives used in
SVr4.
.PP
`\|\c
.B \-msvr3\c
\&\|' is the default for all m88K configurations except
the SVr4 configuration.
.TP
.B \-mtrap\-large\-shift
.TP
.B \-mhandle\-large\-shift
Include code to detect bit-shifts of more than 31 bits; respectively,
trap such shifts or emit code to handle them properly.  By default GCC
makes no special provision for large bit shifts.
.TP
.B \-muse\-div\-instruction
Very early models of the 88K architecture didn't have a divide
instruction, so GCC avoids that instruction by default.  Use this option
to specify that it's safe to use the divide instruction.
.TP
.B \-mversion\-03.00
In the DG/UX configuration, there are two flavors of SVr4.  This option
modifies
.B \-msvr4
to select whether the hybrid-COFF or real-ELF
flavor is used.  All other configurations ignore this option.
.TP
.B \-mwarn\-passed\-structs
Warn when a function passes a struct as an argument or result.
Structure-passing conventions have changed during the evolution of the C
language, and are often the source of portability problems.  By default,
GCC issues no such warning.
.PP
These options are defined for the IBM RS6000:
.PP
.B \-mfp\-in\-toc
.TP
.B \-mno\-fp\-in\-toc
Control whether or not floating-point constants go in the Table of
Contents (TOC), a table of all global variable and function addresses.  By
default GCC puts floating-point constants there; if the TOC overflows,
`\|\c
.B \-mno\-fp\-in\-toc\c
\&\|' will reduce the size of the TOC, which may avoid
the overflow.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the IBM RT PC:
.TP
.B \-min\-line\-mul
Use an in-line code sequence for integer multiplies.  This is the
default.
.TP
.B \-mcall\-lib\-mul
Call \c
.B lmul$$\c
\& for integer multiples.
.TP
.B \-mfull\-fp\-blocks
Generate full-size floating point data blocks, including the minimum
amount of scratch space recommended by IBM.  This is the default.
.TP
.B \-mminimum\-fp\-blocks
Do not include extra scratch space in floating point data blocks.  This
results in smaller code, but slower execution, since scratch space must
be allocated dynamically.
.TP
.B \-mfp\-arg\-in\-fpregs
Use a calling sequence incompatible with the IBM calling convention in
which floating point arguments are passed in floating point registers.
Note that \c
.B varargs.h\c
\& and \c
.B stdargs.h\c
\& will not work with
floating point operands if this option is specified.
.TP
.B \-mfp\-arg\-in\-gregs
Use the normal calling convention for floating point arguments.  This is
the default.
.TP
.B \-mhc\-struct\-return
Return structures of more than one word in memory, rather than in a
register.  This provides compatibility with the MetaWare HighC (hc)
compiler.  Use `\|\c
.B \-fpcc\-struct\-return\c
\&\|' for compatibility with the
Portable C Compiler (pcc).
.TP
.B \-mnohc\-struct\-return
Return some structures of more than one word in registers, when
convenient.  This is the default.  For compatibility with the
IBM-supplied compilers, use either `\|\c
.B \-fpcc\-struct\-return\c
\&\|' or
`\|\c
.B \-mhc\-struct\-return\c
\&\|'.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the MIPS family of computers:
.TP
.BI "\-mcpu=" "cpu-type"
Assume the defaults for the machine type
.I cpu-type
when
scheduling instructions.  The default
.I cpu-type
is
.BR default ,
which picks the longest cycles times for any of the machines, in order
that the code run at reasonable rates on all MIPS cpu's.  Other
choices for
.I cpu-type
are
.BR r2000 ,
.BR r3000 ,
.BR r4000 ,
and
.BR r6000 .
While picking a specific
.I cpu-type
will schedule things appropriately for that particular chip, the
compiler will not generate any code that does not meet level 1 of the
MIPS ISA (instruction set architecture) without the
.B \-mips2
or
.B \-mips3
switches being used.
.TP
.B \-mips2
Issue instructions from level 2 of the MIPS ISA (branch likely, square
root instructions).  The
.B \-mcpu=r4000
or
.B \-mcpu=r6000
switch must be used in conjunction with
.BR \-mips2 .
.TP
.B \-mips3
Issue instructions from level 3 of the MIPS ISA (64 bit instructions).
The
.B \-mcpu=r4000
switch must be used in conjunction with
.BR \-mips2 .
.TP
.B \-mint64
.TP
.B \-mlong64
.TP
.B \-mlonglong128
These options don't work at present.
.TP
.B \-mmips\-as
Generate code for the MIPS assembler, and invoke
.B mips\-tfile
to add normal debug information.  This is the default for all
platforms except for the OSF/1 reference platform, using the OSF/rose
object format.  If any of the
.BR \-ggdb ,
.BR \-gstabs ,
or
.B \-gstabs+
switches are used, the
.B mips\-tfile
program will encapsulate the stabs within MIPS ECOFF.
.TP
.B \-mgas
Generate code for the GNU assembler.  This is the default on the OSF/1
reference platform, using the OSF/rose object format.
.TP
.B \-mrnames
.TP
.B \-mno\-rnames
The
.B \-mrnames
switch says to output code using the MIPS software names for the
registers, instead of the hardware names (ie,
.B a0
instead of
.BR $4 ).
The GNU assembler does not support the
.B \-mrnames
switch, and the MIPS assembler will be instructed to run the MIPS C
preprocessor over the source file.  The
.B \-mno\-rnames
switch is default.
.TP
.B \-mgpopt
.TP
.B \-mno\-gpopt
The
.B \-mgpopt
switch says to write all of the data declarations before the
instructions in the text section, to all the MIPS assembler to
generate one word memory references instead of using two words for
short global or static data items.  This is on by default if
optimization is selected.
.TP
.B \-mstats
.TP
.B \-mno\-stats
For each non-inline function processed, the
.B \-mstats
switch causes the compiler to emit one line to the standard error file
to print statistics about the program (number of registers saved,
stack size, etc.).
.TP
.B \-mmemcpy
.TP
.B \-mno\-memcpy
The
.B \-mmemcpy
switch makes all block moves call the appropriate string function
.RB ( memcpy
or
.BR bcopy )
instead of possibly generating inline code.
.TP
.B \-mmips\-tfile
.TP
.B \-mno\-mips\-tfile
The
.B \-mno\-mips\-tfile
switch causes the compiler not postprocess the object file with the
.B mips\-tfile
program, after the MIPS assembler has generated it to add debug
support.  If
.B mips\-tfile
is not run, then no local variables will be available to the debugger.
In addition,
.B stage2
and
.B stage3
objects will have the temporary file names passed to the assembler
embedded in the object file, which means the objects will not compare
the same.
.TP
.B \-msoft\-float
Generate output containing library calls for floating point.
.I
WARNING:
the requisite libraries are not part of GNU CC.  Normally the
facilities of the machine's usual C compiler are used, but this can't
be done directly in cross-compilation.  You must make your own
arrangements to provide suitable library functions for cross-compilation.
.TP
.B \-mhard\-float
Generate output containing floating point instructions.  This is the
default if you use the unmodified sources.
.TP
.B \-mfp64
Assume that the
.B FR
bit in the status word is on, and that there are 32 64-bit floating
point registers, instead of 32 32-bit floating point registers.  You
must also specify the
.B \-mcpu=r4000
and
.B \-mips3
switches.
.TP
.B \-mfp32
Assume that there are 32 32-bit floating point registers.  This is the
default.
.PP
.B \-mabicalls
.TP
.B \-mno\-abicalls
Emit (or do not emit) the
.BR \&.abicalls ,
.BR \&.cpload ,
and
.B \&.cprestore
pseudo operations that some System V.4 ports use for position
independent code.
.TP
.B \-mhalf\-pic
.TP
.B \-mno\-half\-pic
The
.B \-mhalf\-pic
switch says to put pointers to extern references into the data section
and load them up, rather than put the references in the text section.
This option does not work at present.
.B
.BI \-G num
Put global and static items less than or equal to
.I num
bytes into the small data or bss sections instead of the normal data
or bss section.  This allows the assembler to emit one word memory
reference instructions based on the global pointer
.RB ( gp
or
.BR $28 ),
instead of the normal two words used.  By default,
.I num
is 8 when the MIPS assembler is used, and 0 when the GNU
assembler is used.  The
.BI \-G num
switch is also passed to the assembler and linker.  All modules should
be compiled with the same
.BI \-G num
value.
.TP
.B \-nocpp
Tell the MIPS assembler to not run its preprocessor over user
assembler files (with a `\|\c
.B .s\c
\&\|' suffix) when assembling them.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the Intel 80386 family of computers:
.B \-m486
.TP
.B \-mno\-486
Control whether or not code is optimized for a 486 instead of an
386.  Code generated for a 486 will run on a 386 and vice versa.
.TP
.B \-msoft\-float
Generate output containing library calls for floating point.
.I Warning:
the requisite libraries are not part of GNU CC.
Normally the facilities of the machine's usual C compiler are used, but
this can't be done directly in cross-compilation.  You must make your
own arrangements to provide suitable library functions for
cross-compilation.
.Sp
On machines where a function returns floating point results in the 80387
register stack, some floating point opcodes may be emitted even if
`\|\c
.B \-msoft-float\c
\&\|' is used.
.TP
.B \-mno-fp-ret-in-387
Do not use the FPU registers for return values of functions.
.Sp
The usual calling convention has functions return values of types
.B float\c
\& and \c
.B double\c
\& in an FPU register, even if there
is no FPU.  The idea is that the operating system should emulate
an FPU.
.Sp
The option `\|\c
.B \-mno-fp-ret-in-387\c
\&\|' causes such values to be returned
in ordinary CPU registers instead.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the HPPA family of computers:
.TP
.B \-mpa-risc-1-0
Generate code for a PA 1.0 processor.
.TP
.B \-mpa-risc-1-1
Generate code for a PA 1.1 processor.
.TP
.B \-mkernel
Generate code which is suitable for use in kernels.  Specifically, avoid
.B add\c
\& instructions in which one of the arguments is the DP register;
generate \c
.B addil\c
\& instructions instead.  This avoids a rather serious
bug in the HP-UX linker.
.TP
.B \-mshared-libs
Generate code that can be linked against HP-UX shared libraries.  This option
is not fully function yet, and is not on by default for any PA target.  Using
this option can cause incorrect code to be generated by the compiler.
.TP
.B \-mno-shared-libs
Don't generate code that will be linked against shared libraries.  This is
the default for all PA targets.
.TP
.B \-mlong-calls
Generate code which allows calls to functions greater than 256K away from
the caller when the caller and callee are in the same source file.  Do
not turn this option on unless code refuses to link with \*(lqbranch out of
range errors\*('' from the linker.
.TP
.B \-mdisable-fpregs
Prevent floating point registers from being used in any manner.  This is
necessary for compiling kernels which perform lazy context switching of
floating point registers.  If you use this option and attempt to perform
floating point operations, the compiler will abort.
.TP
.B \-mdisable-indexing
Prevent the compiler from using indexing address modes.  This avoids some
rather obscure problems when compiling MIG generated code under MACH.
.TP
.B \-mtrailing-colon
Add a colon to the end of label definitions (for ELF assemblers).
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the Intel 80960 family of computers:
.TP
.BI "\-m" "cpu-type"
Assume the defaults for the machine type
.I cpu-type
for instruction and addressing-mode availability and alignment.
The default
.I cpu-type
is
.BR kb ;
other choices are
.BR ka ,
.BR mc ,
.BR ca ,
.BR cf ,
.BR sa ,
and
.BR sb .
.TP
.B \-mnumerics
.TP
.B \-msoft\-float
The
.B \-mnumerics
option indicates that the processor does support
floating-point instructions.  The
.B \-msoft\-float
option indicates
that floating-point support should not be assumed.
.TP
.B \-mleaf\-procedures
.TP
.B \-mno\-leaf\-procedures
Do (or do not) attempt to alter leaf procedures to be callable with the
.I bal
instruction as well as
.IR call .
This will result in more
efficient code for explicit calls when the
.I bal
instruction can be
substituted by the assembler or linker, but less efficient code in other
cases, such as calls via function pointers, or using a linker that doesn't
support this optimization.
.TP
.B \-mtail\-call
.TP
.B \-mno\-tail\-call
Do (or do not) make additional attempts (beyond those of the
machine-independent portions of the compiler) to optimize tail-recursive
calls into branches.  You may not want to do this because the detection of
cases where this is not valid is not totally complete.  The default is
.BR \-mno\-tail\-call .
.TP
.B \-mcomplex\-addr
.TP
.B \-mno\-complex\-addr
Assume (or do not assume) that the use of a complex addressing mode is a
win on this implementation of the i960.  Complex addressing modes may not
be worthwhile on the K-series, but they definitely are on the C-series.
The default is currently
.B \-mcomplex\-addr
for all processors except
the CB and CC.
.TP
.B \-mcode\-align
.TP
.B \-mno\-code\-align
Align code to 8-byte boundaries for faster fetching (or don't bother).
Currently turned on by default for C-series implementations only.
.TP
.B \-mic\-compat
.TP
.B \-mic2.0\-compat
.TP
.B \-mic3.0\-compat
Enable compatibility with iC960 v2.0 or v3.0.
.TP
.B \-masm\-compat
.TP
.B \-mintel\-asm
Enable compatibility with the iC960 assembler.
.TP
.B \-mstrict\-align
.TP
.B \-mno\-strict\-align
Do not permit (do permit) unaligned accesses.
.TP
.B \-mold\-align
Enable structure-alignment compatibility with Intel's gcc release version
1.3 (based on gcc 1.37).  Currently this is buggy in that
.B #pragma align 1
is always assumed as well, and cannot be turned off.
.PP
These `\|\c
.B \-m\c
\&\|' options are defined for the DEC Alpha implementations:
.TP
.B \-mno-soft-float
.TP
.B \-msoft-float
Use (do not use) the hardware floating-point instructions for
floating-point operations.  When \c
.B \-msoft-float\c
\& is specified,
functions in `\|\c
.B libgcc1.c\c
\&\|' will be used to perform floating-point
operations.  Unless they are replaced by routines that emulate the
floating-point operations, or compiled in such a way as to call such
emulations routines, these routines will issue floating-point
operations.   If you are compiling for an Alpha without floating-point
operations, you must ensure that the library is built so as not to call
them.
.Sp
Note that Alpha implementations without floating-point operations are
required to have floating-point registers.
.TP
.B \-mfp-reg
.TP
.B \-mno-fp-regs
Generate code that uses (does not use) the floating-point register set.
.B \-mno-fp-regs\c
\& implies \c
.B \-msoft-float\c
\&.  If the floating-point
register set is not used, floating point operands are passed in integer
registers as if they were integers and floating-point results are passed
in $0 instead of $f0.  This is a non-standard calling sequence, so any
function with a floating-point argument or return value called by code
compiled with \c
.B \-mno-fp-regs\c
\& must also be compiled with that
option.
.Sp
A typical use of this option is building a kernel that does not use,
and hence need not save and restore, any floating-point registers.
.PP
These additional options are available on System V Release 4 for
compatibility with other compilers on those systems:
.TP
.B \-G
On SVr4 systems, \c
.B gcc\c
\& accepts the option `\|\c
.B \-G\c
\&\|' (and passes
it to the system linker), for compatibility with other compilers.
However, we suggest you use `\|\c
.B \-symbolic\c
\&\|' or `\|\c
.B \-shared\c
\&\|' as
appropriate, instead of supplying linker options on the \c
.B gcc
command line.
.TP
.B \-Qy
Identify the versions of each tool used by the compiler, in a
.B .ident\c
\& assembler directive in the output.
.TP
.B \-Qn
Refrain from adding \c
.B .ident\c
\& directives to the output file (this is
the default).
.TP
.BI "\-YP," "dirs"
Search the directories \c
.I dirs\c
\&, and no others, for libraries
specified with `\|\c
.B \-l\c
\&\|'.  You can separate directory entries in
.I dirs\c
\& from one another with colons.
.TP
.BI "\-Ym," "dir"
Look in the directory \c
.I dir\c
\& to find the M4 preprocessor.
The assembler uses this option.
.SH CODE GENERATION OPTIONS
These machine-independent options control the interface conventions
used in code generation.
.PP
Most of them begin with `\|\c
\-f\c
\&\|'.  These options have both positive and negative forms; the negative form
of `\|\c
.B \-ffoo\c
\&\|' would be `\|\c
.B \-fno\-foo\c
\&\|'.  In the table below, only
one of the forms is listed\(em\&the one which is not the default.  You
can figure out the other form by either removing `\|\c
.B no\-\c
\&\|' or adding
it.
.TP
.B \-fnonnull\-objects
Assume that objects reached through references are not null
(C++ only).
.Sp
Normally, GNU C++ makes conservative assumptions about objects reached
through references.  For example, the compiler must check that \c
.B a
is not null in code like the following:
.Sp
obj &a = g ();
a.f (2);
.Sp
Checking that references of this sort have non-null values requires
extra code, however, and it is unnecessary for many programs.  You can
use `\|\c
.B \-fnonnull-objects\c
\&\|' to omit the checks for null, if your
program doesn't require checking.
.TP
.B \-fpcc\-struct\-return
Use the same convention for returning \c
.B struct\c
\& and \c
.B union
values that is used by the usual C compiler on your system.  This
convention is less efficient for small structures, and on many
machines it fails to be reentrant; but it has the advantage of
allowing intercallability between GCC-compiled code and PCC-compiled
code.
.TP
.B \-freg\-struct\-return
Use the convention that
.B struct
and
.B union
values are returned in registers when possible.  This is more
efficient for small structures than
.BR \-fpcc\-struct\-return .
.Sp
If you specify neither
.B \-fpcc\-struct\-return
nor
.BR \-freg\-struct\-return ,
GNU CC defaults to whichever convention is standard for the target.
If there is no standard convention, GNU CC defaults to
.BR \-fpcc\-struct\-return .
.TP
.B \-fshort\-enums
Allocate to an \c
.B enum\c
\& type only as many bytes as it needs for the
declared range of possible values.  Specifically, the \c
.B enum\c
\& type
will be equivalent to the smallest integer type which has enough room.
.TP
.B \-fshort\-double
Use the same size for
.B double
as for
.B float
\&.
.TP
.B \-fshared\-data
Requests that the data and non-\c
.B const\c
\& variables of this
compilation be shared data rather than private data.  The distinction
makes sense only on certain operating systems, where shared data is
shared between processes running the same program, while private data
exists in one copy per process.
.TP
.B \-fno\-common
Allocate even uninitialized global variables in the bss section of the
object file, rather than generating them as common blocks.  This has the
effect that if the same variable is declared (without \c
.B extern\c
\&) in
two different compilations, you will get an error when you link them.
The only reason this might be useful is if you wish to verify that the
program will work on other systems which always work this way.
.TP
.B \-fno\-ident
Ignore the `\|\c
.B #ident\c
\&\|' directive.
.TP
.B \-fno\-gnu\-linker
Do not output global initializations (such as C++ constructors and
destructors) in the form used by the GNU linker (on systems where the GNU
linker is the standard method of handling them).  Use this option when
you want to use a non-GNU linker, which also requires using the
.B collect2\c
\& program to make sure the system linker includes
constructors and destructors.  (\c
.B collect2\c
\& is included in the GNU CC
distribution.)  For systems which \c
.I must\c
\& use \c
.B collect2\c
\&, the
compiler driver \c
.B gcc\c
\& is configured to do this automatically.
.TP
.B \-finhibit-size-directive
Don't output a \c
.B .size\c
\& assembler directive, or anything else that
would cause trouble if the function is split in the middle, and the
two halves are placed at locations far apart in memory.  This option is
used when compiling `\|\c
.B crtstuff.c\c
\&\|'; you should not need to use it
for anything else.
.TP
.B \-fverbose-asm
Put extra commentary information in the generated assembly code to
make it more readable.  This option is generally only of use to those
who actually need to read the generated assembly code (perhaps while
debugging the compiler itself).
.TP
.B \-fvolatile
Consider all memory references through pointers to be volatile.
.TP
.B \-fvolatile\-global
Consider all memory references to extern and global data items to
be volatile.
.TP
.B \-fpic
If supported for the target machines, generate position-independent code,
suitable for use in a shared library.
.TP
.B \-fPIC
If supported for the target machine, emit position-independent code,
suitable for dynamic linking, even if branches need large displacements.
.TP
.BI "\-ffixed\-" "reg"
Treat the register named \c
.I reg\c
\& as a fixed register; generated code
should never refer to it (except perhaps as a stack pointer, frame
pointer or in some other fixed role).
.Sp
.I reg\c
\& must be the name of a register.  The register names accepted
are machine-specific and are defined in the \c
.B REGISTER_NAMES
macro in the machine description macro file.
.Sp
This flag does not have a negative form, because it specifies a
three-way choice.
.TP
.BI "\-fcall\-used\-" "reg"
Treat the register named \c
.I reg\c
\& as an allocable register that is
clobbered by function calls.  It may be allocated for temporaries or
variables that do not live across a call.  Functions compiled this way
will not save and restore the register \c
.I reg\c
\&.
.Sp
Use of this flag for a register that has a fixed pervasive role in the
machine's execution model, such as the stack pointer or frame pointer,
will produce disastrous results.
.Sp
This flag does not have a negative form, because it specifies a
three-way choice.
.TP
.BI "\-fcall\-saved\-" "reg"
Treat the register named \c
.I reg\c
\& as an allocable register saved by
functions.  It may be allocated even for temporaries or variables that
live across a call.  Functions compiled this way will save and restore
the register \c
.I reg\c
\& if they use it.
.Sp
Use of this flag for a register that has a fixed pervasive role in the
machine's execution model, such as the stack pointer or frame pointer,
will produce disastrous results.
.Sp
A different sort of disaster will result from the use of this flag for
a register in which function values may be returned.
.Sp
This flag does not have a negative form, because it specifies a
three-way choice.
.SH PRAGMAS
Two `\|\c
.B #pragma\c
\&\|' directives are supported for GNU C++, to permit using the same
header file for two purposes: as a definition of interfaces to a given
object class, and as the full definition of the contents of that object class.
.TP
.B #pragma interface
(C++ only.)
Use this directive in header files that define object classes, to save
space in most of the object files that use those classes.  Normally,
local copies of certain information (backup copies of inline member
functions, debugging information, and the internal tables that
implement virtual functions) must be kept in each object file that
includes class definitions.  You can use this pragma to avoid such
duplication.  When a header file containing `\|\c
.B #pragma interface\c
\&\|' is included in a compilation, this auxiliary information
will not be generated (unless the main input source file itself uses
`\|\c
.B #pragma implementation\c
\&\|').  Instead, the object files will contain references to be
resolved at link time.
.TP
.B #pragma implementation
.TP
\fB#pragma implementation "\fP\fIobjects\fP\fB.h"\fP
(C++ only.)
Use this pragma in a main input file, when you want full output from
included header files to be generated (and made globally visible).
The included header file, in turn, should use `\|\c
.B #pragma interface\c
\&\|'.
Backup copies of inline member functions, debugging information, and
the internal tables used to implement virtual functions are all
generated in implementation files.
.Sp
If you use `\|\c
.B #pragma implementation\c
\&\|' with no argument, it applies to an include file with the same
basename as your source file; for example, in `\|\c
.B allclass.cc\c
\&\|', `\|\c
.B #pragma implementation\c
\&\|' by itself is equivalent to `\|\c
.B
#pragma implementation "allclass.h"\c
\&\|'.  Use the string argument if you want a single implementation
file to include code from multiple header files.
.Sp
There is no way to split up the contents of a single header file into
multiple implementation files.
.SH FILES
.nf
.ta \w'LIBDIR/g++\-include 'u
file.c	C source file
file.h	C header (preprocessor) file
file.i	preprocessed C source file
file.C	C++ source file
file.cc	C++ source file
file.cxx	C++ source file
file.m	Objective-C source file
file.s	assembly language file
file.o	object file
a.out	link edited output
\fITMPDIR\fR/cc\(**	temporary files
\fILIBDIR\fR/cpp	preprocessor
\fILIBDIR\fR/cc1	compiler for C
\fILIBDIR\fR/cc1plus	compiler for C++
\fILIBDIR\fR/collect	linker front end needed on some machines
\fILIBDIR\fR/libgcc.a	GCC subroutine library
/lib/crt[01n].o	start-up routine
\fILIBDIR\fR/ccrt0	additional start-up routine for C++
/lib/libc.a	standard C library, see
.IR intro (3)
/usr/include	standard directory for \fB#include\fP files
\fILIBDIR\fR/include	standard gcc directory for \fB#include\fP files
\fILIBDIR\fR/g++\-include	additional g++ directory for \fB#include\fP
.Sp
.fi
.I LIBDIR
is usually
.B /usr/local/lib/\c
.IR machine / version .
.br
.I TMPDIR
comes from the environment variable
.B TMPDIR
(default
.B /usr/tmp
if available, else
.B /tmp\c
\&).
.SH "SEE ALSO"
cpp(1), as(1), ld(1), gdb(1), adb(1), dbx(1), sdb(1).
.br
.RB "`\|" gcc "\|', `\|" cpp \|',
.RB "`\|" as "\|', `\|" ld \|',
and
.RB `\| gdb \|'
entries in
.B info\c
\&.
.br
.I
Using and Porting GNU CC (for version 2.0)\c
, Richard M. Stallman;
.I
The C Preprocessor\c
, Richard M. Stallman;
.I
Debugging with GDB: the GNU Source-Level Debugger\c
, Richard M. Stallman and Roland H. Pesch;
.I
Using as: the GNU Assembler\c
, Dean Elsner, Jay Fenlason & friends;
.I
ld: the GNU linker\c
, Steve Chamberlain and Roland Pesch.
.SH BUGS
For instructions on reporting bugs, see the GCC manual.
.SH COPYING
Copyright
.if t \(co
1991, 1992, 1993 Free Software Foundation, Inc.
.PP
Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice
are preserved on all copies.
.PP
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
.PP
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be included in
translations approved by the Free Software Foundation instead of in
the original English.
.SH AUTHORS
See the GNU CC Manual for the contributors to GNU CC.