Change #278811

Comments

In PCAP_BSWAP_ use compiler builtins if available.
Similarly to __builtin_ctz() earlier, for each of __builtin_bswap16(),
__builtin_bswap32() and __builtin_bswap64() test if the compiler
implements the builtin and use it instead of the respective bulky
byte-swapping expression.  Add comments to clarify that different
builtins require different methods of testing.

Changed files

• CMakeLists.txt
• cmakeconfig.h.in
• configure.ac
• optimize.c
• pcap-util.h