Re: Change initialization order in sel-sched

2012-04-17 Thread Alexander Monakov 

On Wed, 11 Apr 2012, Richard Guenther wrote:

 On Wed, Apr 11, 2012 at 4:16 PM, Bernd Schmidt ber...@codesourcery.com 
 wrote:
  The order of calls to sched_rgn_init and sched_init differs between
  sched-rgn and sel-sched. This caused a scheduler patch I was working on
  to segfault once sel-sched was enabled. The following patch swaps the
  two function calls.
 
  Bootstrapped  tested on i686-linux. Ok?
 
 Ok.
 
 Thanks,
 Richard.

Actually, this causes miscompilations with selective scheduler when
-fsel-sched-pipelining is enabled (as it is with -O3 on ia64).  The reason is,
with that flag we build custom regions that consist of a loop body and its
preheader in sel_find_rgns, which is called from sched_rgn_init.  We require
that sched_init is called afterwards, so that DF data is computed for any new
blocks that might have been created (i.e. preheaders); it's possible that DF
is not the only thing that forces this order.

Bernd, could you elaborate on the segfault you had seen?  Perhaps we could
offer some advice on fixing it then.

In the meanwhile, could you revert your patch?  I'm sorry to point out this
problem after the patch had been committed, but it's not immediately obvious :)
Andrey or I will add an explanatory comment in sel-sched afterwards.

Alexander

Re: Change initialization order in sel-sched

2012-04-17 Thread Bernd Schmidt 
On 04/17/2012 03:33 PM, Alexander Monakov wrote:
 Bernd, could you elaborate on the segfault you had seen?  Perhaps we could
 offer some advice on fixing it then.

It was only seen with another patch which modified the sched-rgn
initialization code.

 In the meanwhile, could you revert your patch?  I'm sorry to point out this
 problem after the patch had been committed, but it's not immediately obvious 
 :)
 Andrey or I will add an explanatory comment in sel-sched afterwards.

Will revert for now. In general I think it would be better to change
sel-sched so that the init functions can always be called in the same
order, so as to avoid unnecessary surprises.


Bernd

Change initialization order in sel-sched

2012-04-11 Thread Bernd Schmidt 
The order of calls to sched_rgn_init and sched_init differs between
sched-rgn and sel-sched. This caused a scheduler patch I was working on
to segfault once sel-sched was enabled. The following patch swaps the
two function calls.

Bootstrapped  tested on i686-linux. Ok?


Bernd
* sel-sched.c (sel_global_init): Swap order of sched_rgn_init and
sched_init calls.

Index: gcc/sel-sched.c
===
--- gcc/sel-sched.c (revision 364953)
+++ gcc/sel-sched.c (working copy)
@@ -7616,8 +7616,8 @@ sel_global_init (void)
   sel_setup_sched_infos ();
   setup_sched_dump ();
 
-  sched_rgn_init (false);
   sched_init ();
+  sched_rgn_init (false);
 
   sched_init_bbs ();
   /* Reset AFTER_RECOVERY if it has been set by the 1st scheduler pass.  */

Re: Change initialization order in sel-sched

2012-04-11 Thread Richard Guenther 
On Wed, Apr 11, 2012 at 4:16 PM, Bernd Schmidt ber...@codesourcery.com wrote:
 The order of calls to sched_rgn_init and sched_init differs between
 sched-rgn and sel-sched. This caused a scheduler patch I was working on
 to segfault once sel-sched was enabled. The following patch swaps the
 two function calls.

 Bootstrapped  tested on i686-linux. Ok?

Ok.

Thanks,
Richard.


 Bernd