ping.
On Fri, Sep 27, 2013 at 3:53 PM, Rong Xu <x...@google.com> wrote: > Hi, > > > > Current default probability for builtin_expect is 0.9996. > This makes the freq of unlikely bb very low (4), which > suppresses the inlining of any calls within those bb. > > We used FDO data to measure the branch probably for > the branch annotated with builtin_expert. > For google internal benchmarks, the weight average > (the profile count value as the weight) is 0.9081. > > Linux kernel is another program that is heavily annotated > with builtin-expert. We measured its weight average as 0.8717, > using google search as the workload. > > This patch sets the alternate hirate probability for builtin_expert > to 90%. With the alternate hirate, we measured performance > improvement for google benchmarks and Linux kernel. > > An earlier discussion is > https://mail.google.com/mail/u/0/?pli=1#label/gcc-paches/1415c5910054630b > > This new patch is for the trunk and addresses Honza's comments. > > Honza: this new probability is off by default. When we backport to google > branch we will make it the default. Let me know if you want to do the same > here. > > Thanks, > > -Rong
