[cygnus.project.sid] branch probability hinting

Thu Mar 1 01:23:00 GMT 2001

Tom Tromey writes:
 > I've always thought the __builtin_expect code in libgcj was a bit
 > ugly. I find it hard to read and understand.
 > 
 > I think we ought to adopt macros like the appended.
I think the macros should be used in parens:
 if UNLIKELY(error)
is non-idiomatic C.
 if (UNLIKELY(error))
is better IMO. Otherwise this is a good idea; I've never liked the
builtin_expect syntax much.
Also please everyone note that the compiler already knows that
 if (p == NULL)
is unlikely, so let's not obfuscate our code unnecessarily.
Andrew.