Microsoft (R) C/C++ Optimizing Compiler Version 8.00c Compile with /O2 chokes the compiler on these files crypto\md\md5_dgst.c warning '@(#)reg86.c:1.26', line 1110 crypto\des\ofb64ede.c warning '@(#)grammar.c:1.147', line 168 crypto\des\ofb64enc.c warning '@(#)grammar.c:1.147', line 168 crypto\des\qud_cksm.c warning '@(#)grammar.c:1.147', line 168 crypto\rc2\rc2ofb64.c warning '@(#)grammar.c:1.147', line 168 crypto\objects\obj_dat.c warning '@(#)grammar.c:1.147', line 168 fatal '@(#)grammar.c:1.147', line 168 crypto\objects\obj_lib.c warning '@(#)grammar.c:1.147', line 168 fatal '@(#)grammar.c:1.147', line 168 ssl\ssl_auth.c warning '@(#)grammar.c:1.147', line 168 fatal '@(#)grammar.c:1.147', line 168 Turning on /G3 with build flags that worked fine for /G2 came up with divide by zero errors in 'normal' code in speed.c :-(