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Re: [PATCH] Fix PR60911


> On Thu, 24 Apr 2014, Jan Hubicka wrote:
> 
> > > 
> > > Simple IPA passes are supposed to see function bodies with IPA transforms 
> > > applied - this is what the code in execute_one_pass tries to ensure.
> > > But that doesn't work anymore with on-demand function-body loading.
> > > The following addresses this in the least intrusive way - inlining
> > > do_per_function (apply_ipa_transforms) and adjusting it accordingly.
> > > 
> > > This IMHO is definitely the solution for the 4.9 branch (and for
> > > the time being on trunk).
> > > 
> > > Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
> > > 
> > > Ok for trunk and branch?
> > 
> > I think it is fine for both 4.9 and mainline. I will try to make better version
> > for mainline as explained in PR hortly.
> > 
> > Can you, please, double check that it won't load all bodies prior late 
> > optimization by default? Looking at gate of pass_omp_simd_clone, perhaps 
> 
> Well, first of all it will only load bodies with IPA transforms to apply
> (yeah, that includes inlining, right?).  Then it's only executed if
> a small IPA pass actually executes, but ...

All functions have transforms to apply. They are added to all bodies of
functions that are around when pass is run. Not only to those pass wants to do
something. This is how first cut got implemented in 2004 and it is still the
same. We may want to change this, since the per-function transform lists tends
to be memory consuming these days. The reason why the lists are per-function
was that I expected IPA passes to introduce new functions in the middle of
optimization processing (it now happens for sample with ctor merging) and those
sould not be processed by transforms of IPA passes that never see them.
> 
> > it actually kills late loading of bodies and perhaps we need to mark in 
> > cgraph node whether the given node needs clonning and page the gate 
> > return false if partition has no such unit? bool 
> > pass_omp_simd_clone::gate (function *) {
> >   return ((flag_openmp || flag_openmp_simd
> >            || flag_cilkplus
> >            || (in_lto_p && !flag_wpa))
> >           && (targetm.simd_clone.compute_vecsize_and_simdlen != NULL));
> > }
> > 
> > I did not see there the in_lto_p previously.
> 
> ... this is IIRC because you can't rely on -fopenmp/-fopenmp-simd/-fcilk+
> to be present on the LTO commandline.

Yep, together with your change it will kill lazy loading, because the pass is
practicaly unconditoinal with LTO and all functions will have transforms on them.
Adding simple flag if function needs openmp_simd processing would solve it.

Honza
> 
> Richard.
> 
> > Honza
> > > 
> > > Thanks,
> > > Richard.
> > > 
> > > 2014-04-24  Richard Biener  <rguenther@suse.de>
> > > 
> > > 	PR ipa/60911
> > > 	* passes.c (apply_ipa_transforms): Inline into only caller ...
> > > 	(execute_one_pass): ... here.  Properly bring in function
> > > 	bodies for nodes we want to apply IPA transforms to.
> > > 
> > > 	* gcc.dg/lto/pr60911_0.c: New testcase.
> > > 
> > > Index: gcc/passes.c
> > > ===================================================================
> > > --- gcc/passes.c	(revision 209742)
> > > +++ gcc/passes.c	(working copy)
> > > @@ -2109,20 +2109,6 @@ execute_all_ipa_transforms (void)
> > >      }
> > >  }
> > >  
> > > -/* Callback for do_per_function to apply all IPA transforms.  */
> > > -
> > > -static void
> > > -apply_ipa_transforms (void *data)
> > > -{
> > > -  struct cgraph_node *node = cgraph_get_node (current_function_decl);
> > > -  if (!node->global.inlined_to && node->ipa_transforms_to_apply.exists ())
> > > -    {
> > > -      *(bool *)data = true;
> > > -      execute_all_ipa_transforms ();
> > > -      rebuild_cgraph_edges ();
> > > -    }
> > > -}
> > > -
> > >  /* Check if PASS is explicitly disabled or enabled and return
> > >     the gate status.  FUNC is the function to be processed, and
> > >     GATE_STATUS is the gate status determined by pass manager by
> > > @@ -2194,8 +2180,26 @@ execute_one_pass (opt_pass *pass)
> > >       Apply all trnasforms first.  */
> > >    if (pass->type == SIMPLE_IPA_PASS)
> > >      {
> > > +      struct cgraph_node *node;
> > >        bool applied = false;
> > > -      do_per_function (apply_ipa_transforms, (void *)&applied);
> > > +      FOR_EACH_DEFINED_FUNCTION (node)
> > > +	if (node->analyzed
> > > +	    && cgraph_function_with_gimple_body_p (node)
> > > +	    && (!node->clone_of || node->decl != node->clone_of->decl))
> > > +	  {
> > > +	    if (!node->global.inlined_to
> > > +		&& node->ipa_transforms_to_apply.exists ())
> > > +	      {
> > > +		cgraph_get_body (node);
> > > +		push_cfun (DECL_STRUCT_FUNCTION (node->decl));
> > > +		execute_all_ipa_transforms ();
> > > +		rebuild_cgraph_edges ();
> > > +		free_dominance_info (CDI_DOMINATORS);
> > > +		free_dominance_info (CDI_POST_DOMINATORS);
> > > +		pop_cfun ();
> > > +		applied = true;
> > > +	      }
> > > +	  }
> > >        if (applied)
> > >          symtab_remove_unreachable_nodes (true, dump_file);
> > >        /* Restore current_pass.  */
> > > Index: gcc/testsuite/gcc.dg/lto/pr60911_0.c
> > > ===================================================================
> > > --- gcc/testsuite/gcc.dg/lto/pr60911_0.c	(revision 0)
> > > +++ gcc/testsuite/gcc.dg/lto/pr60911_0.c	(working copy)
> > > @@ -0,0 +1,21 @@
> > > +// { dg-lto-do run }
> > > +// { dg-lto-options { { -O2 -flto -fipa-pta } } }
> > > +
> > > +int __attribute__ ((__noinline__)) f (unsigned *p, int *x)
> > > +{
> > > +  int y = *p++ & 0xfff;
> > > +  *x++ = y;
> > > +  *x = *p;
> > > +  return y;
> > > +}
> > > +
> > > +int
> > > +main ()
> > > +{
> > > +  unsigned u[2] = { 0x3aad, 0x5ad1 };
> > > +  int x[2] = { 17689, 23456 };
> > > +
> > > +  if (f (u, x) != 0xaad || x[0] != 0xaad || x[1] != 0x5ad1)
> > > +    __builtin_abort ();
> > > +  return 0;
> > > +}
> > 
> > 
> 
> -- 
> Richard Biener <rguenther@suse.de>
> SUSE / SUSE Labs
> SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
> GF: Jeff Hawn, Jennifer Guild, Felix Imend"orffer


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