Re: use of LIKELY() and UNLIKELY() branch predictors

Dave Mitchell wrote:
> Perl defines the LIKELY() and UNLIKELY() macros, which (under gcc)
> tell the compiler whether a particular expression is likely to be true or
> not. This allows you to re-write something like

Why do it by hand, rather than use 
http://en.wikipedia.org/wiki/Profile-guided_optimization with a real 
work load (what is a real workload?)?

• use of LIKELY() and UNLIKELY() branch predictors by Dave Mitchell
• Re: use of LIKELY() and UNLIKELY() branch predictors by bulk88
• Re: use of LIKELY() and UNLIKELY() branch predictors by Dave Mitchell
• Re: use of LIKELY() and UNLIKELY() branch predictors by Tim Bunce
• Re: use of LIKELY() and UNLIKELY() branch predictors by Dave Mitchell
• Re: use of LIKELY() and UNLIKELY() branch predictors by Steffen Mueller
• Re: use of LIKELY() and UNLIKELY() branch predictors by bulk88
• Re: use of LIKELY() and UNLIKELY() branch predictors by Zefram
• Re: use of LIKELY() and UNLIKELY() branch predictors by Steffen Mueller
• Re: use of LIKELY() and UNLIKELY() branch predictors by Nicholas Clark
• Re: use of LIKELY() and UNLIKELY() branch predictors by Zefram
• Re: use of LIKELY() and UNLIKELY() branch predictors by David Cantrell
• Re: use of LIKELY() and UNLIKELY() branch predictors by Tim Bunce
• Re: use of LIKELY() and UNLIKELY() branch predictors by demerphq
• Re: use of LIKELY() and UNLIKELY() branch predictors by Zefram
• Re: use of LIKELY() and UNLIKELY() branch predictors by hv
• Re: use of LIKELY() and UNLIKELY() branch predictors by Zefram
• Re: use of LIKELY() and UNLIKELY() branch predictors by Tim Bunce
• Re: use of LIKELY() and UNLIKELY() branch predictors by Dave Mitchell
• Re: use of LIKELY() and UNLIKELY() branch predictors by Nicholas Clark