Edmar Wienskoski
Cc: Steven Bosscher; Jan Hubicka; gcc@gcc.gnu.org; sdkteam-gnu
Subject: RE: branch probabilities on multiway branches
Thanks Edmar! I will try and work your patch into our GCC 4.4.1
port and get some results.
Cheers,
Rahul
Thanks Edmar! I will try and work your patch into our GCC 4.4.1
port and get some results.
Cheers,
Rahul
Hi Steven,
> There is a transformation implemented in GCC's
> value profiling to put the most-frequently taken case-label of a
> switch-expr at the top of the switch
Could you point me to the bit of code that does this?
I'm exploring the idea of implementing source hints much like
__builtin_expe
> On Thu, Apr 15, 2010 at 1:11 PM, Rahul Kharche wrote:
> > The calculate branch probabilities algorithm (1) in the Wu Larus paper
> > also evenly distributes branch probabilities when number of outgoing
> > edges is > 2, e.g. switch cases implemented as jump tables.
> >
> > Are they any known heu
The other case I'm working on is to selectively apply tailcall
optimization when optimizing for size. Clearly tail call optimiztion
is desirable along frequently executed edges. Otherwise we found
tailcall optimization generates a sicall_epilogue for each tailcall
which has a significant impact on
>>What is the problem you're trying to solve?
Generally speaking I was looking for a better logic based on estimated
branch probability to decide between using binary search tree and jump
table implementation of a switch case.
One interesting test case is where the gross structure of a function
i
On Thu, Apr 15, 2010 at 1:11 PM, Rahul Kharche wrote:
> The calculate branch probabilities algorithm (1) in the Wu Larus paper
> also evenly distributes branch probabilities when number of outgoing
> edges is > 2, e.g. switch cases implemented as jump tables.
>
> Are they any known heuristics to g
ase?
-Original Message-
From: Jan Hubicka [mailto:hubi...@ucw.cz]
Sent: 14 April 2010 00:44
To: Rahul Kharche
Cc: gcc@gcc.gnu.org; sdkteam-gnu
Subject: Re: branch probabilities on multiway branches
> Hi All,
>
> The following bit of code in predict.c implies branch probabilities
> are
> Hi All,
>
> The following bit of code in predict.c implies branch probabilities
> are strictly evenly distributed for multiway branches at present. The
> comment suggests it is possible to generate better estimates for more
> generic cases, apart from being involved. Could anyone point me to
> t
