This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: 100x perfomance regression between gcc 3.4.5 and gcc 4.X


On 3/12/06, Steven Bosscher <stevenb.gcc@gmail.com> wrote:
> > Yes, why is the benchmark not valid?
>
> It is valid.  We should understand why this behavior has changed so drastically.
This benchmark maybe useless, it still exposes a weakness of gcc4. At
least it's not news to me:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21195

So that PR has been closed when gcc-devs marked all those intrinsics
as force_inline. That's also the kludge i use with my code. The real
problem is once you start marking some functions as force_inline, you
upset the inlining heuristic even more creating even more silly
inlining misses, rince, repeat.
At the end of the day, everything is marked either force_inline or
noinline and you'd be better off without a heuristic at all.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]