Re: [PATCH] Fix PR60911

[Jan Hubicka <hubicka@ucw.cz>]

> 
> 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 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.

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;
> +}