Re: [PATCH 2/n] OpenMP 4.0 offloading infrastructure: LTO streaming

[Richard Biener <rguenther@suse.de>]

On Wed, 5 Nov 2014, Ilya Verbin wrote:

> On 03 Nov 10:24, Jakub Jelinek wrote:
> > On Tue, Oct 28, 2014 at 10:30:47PM +0300, Ilya Verbin wrote:
> > > @@ -474,6 +475,13 @@ cgraph_node::create (tree decl)
> > >    gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
> > >  
> > >    node->decl = decl;
> > > +
> > > +  if (lookup_attribute ("omp declare target", DECL_ATTRIBUTES (decl)))
> > > +    {
> > > +      node->offloadable = 1;
> > > +      g->have_offload = true;
> > > +    }
> > 
> > I wonder if we shouldn't optimize here and call lookup_attribute only
> > if there is a chance that the attribute might be present, so guard with
> > flag_openmp (and flag_openacc later on?).  During LTO the cgraph nodes
> > are streamed in and supposedly the flag offloadable too.
> > 
> > > @@ -2129,8 +2141,12 @@ symbol_table::compile (void)
> > >      fprintf (stderr, "Performing interprocedural optimizations\n");
> > >    state = IPA;
> > >  
> > > +  /* OpenMP offloading requires LTO infrastructure.  */
> > > +  if (!in_lto_p && flag_openmp && g->have_offload)
> > > +    flag_generate_lto = 1;
> > 
> > On the other side, do you need flag_openmp here?  Supposedly g->have_offload
> > would already been set if needed.
> 
> Done, flag_openmp moved from symbol_table::compile to cgraph_node::create and
> varpool_node::get_create.  OK for trunk?

Yes.

> Maybe also with this change?
> 
> diff --git a/gcc/omp-low.c b/gcc/omp-low.c
> index 4e9ed25..beae5b5 100644
> --- a/gcc/omp-low.c
> +++ b/gcc/omp-low.c
> @@ -1653,8 +1653,7 @@ scan_sharing_clauses (tree clauses, omp_context *ctx)
>  	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
>  	      && DECL_P (decl)
>  	      && is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx))
> -	      && lookup_attribute ("omp declare target",
> -				   DECL_ATTRIBUTES (decl)))
> +	      && varpool_node::get_create (decl)->offloadable)
>  	    break;
>  	  if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_MAP
>  	      && OMP_CLAUSE_MAP_KIND (c) == OMP_CLAUSE_MAP_POINTER)
> @@ -1794,8 +1793,7 @@ scan_sharing_clauses (tree clauses, omp_context *ctx)
>  	  decl = OMP_CLAUSE_DECL (c);
>  	  if (DECL_P (decl)
>  	      && is_global_var (maybe_lookup_decl_in_outer_ctx (decl, ctx))
> -	      && lookup_attribute ("omp declare target",
> -				   DECL_ATTRIBUTES (decl)))
> +	      && varpool_node::get_create (decl)->offloadable)
>  	    break;
>  	  if (DECL_P (decl))
>  	    {

Yes please.

Please make sure that regular LTO bootstrap still works - LTO is
only tested lightly in the testsuite.

Thanks,
Richard.

> Thanks,
>   -- Ilya
> 
> 
> ---
> 
> diff --git a/gcc/cgraph.c b/gcc/cgraph.c
> index 9a47ba2..a491886 100644
> --- a/gcc/cgraph.c
> +++ b/gcc/cgraph.c
> @@ -70,6 +70,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "tree-dfa.h"
>  #include "profile.h"
>  #include "params.h"
> +#include "context.h"
>  
>  /* FIXME: Only for PROP_loops, but cgraph shouldn't have to know about this.  */
>  #include "tree-pass.h"
> @@ -474,6 +475,14 @@ cgraph_node::create (tree decl)
>    gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
>  
>    node->decl = decl;
> +
> +  if (flag_openmp
> +      && lookup_attribute ("omp declare target", DECL_ATTRIBUTES (decl)))
> +    {
> +      node->offloadable = 1;
> +      g->have_offload = true;
> +    }
> +
>    node->register_symbol ();
>  
>    if (DECL_CONTEXT (decl) && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL)
> diff --git a/gcc/cgraph.h b/gcc/cgraph.h
> index 377adce..4988f2d 100644
> --- a/gcc/cgraph.h
> +++ b/gcc/cgraph.h
> @@ -463,6 +463,13 @@ public:
>    /* Set when init priority is set.  */
>    unsigned in_init_priority_hash : 1;
>  
> +  /* Set when symbol needs to be streamed into LTO bytecode for LTO, or in case
> +     of offloading, for separate compilation for a different target.  */
> +  unsigned need_lto_streaming : 1;
> +
> +  /* Set when symbol can be streamed into bytecode for offloading.  */
> +  unsigned offloadable : 1;
> +
>  
>    /* Ordering of all symtab entries.  */
>    int order;
> diff --git a/gcc/cgraphunit.c b/gcc/cgraphunit.c
> index 3e76bf0..83ab419 100644
> --- a/gcc/cgraphunit.c
> +++ b/gcc/cgraphunit.c
> @@ -218,6 +218,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "tree-nested.h"
>  #include "gimplify.h"
>  #include "dbgcnt.h"
> +#include "lto-section-names.h"
>  
>  /* Queue of cgraph nodes scheduled to be added into cgraph.  This is a
>     secondary queue used during optimization to accommodate passes that
> @@ -2049,7 +2050,18 @@ ipa_passes (void)
>      targetm.asm_out.lto_start ();
>  
>    if (!in_lto_p)
> -    ipa_write_summaries ();
> +    {
> +      if (g->have_offload)
> +	{
> +	  section_name_prefix = OFFLOAD_SECTION_NAME_PREFIX;
> +	  ipa_write_summaries (true);
> +	}
> +      if (flag_lto)
> +	{
> +	  section_name_prefix = LTO_SECTION_NAME_PREFIX;
> +	  ipa_write_summaries (false);
> +	}
> +    }
>  
>    if (flag_generate_lto)
>      targetm.asm_out.lto_end ();
> @@ -2129,8 +2141,12 @@ symbol_table::compile (void)
>      fprintf (stderr, "Performing interprocedural optimizations\n");
>    state = IPA;
>  
> +  /* Offloading requires LTO infrastructure.  */
> +  if (!in_lto_p && g->have_offload)
> +    flag_generate_lto = 1;
> +
>    /* If LTO is enabled, initialize the streamer hooks needed by GIMPLE.  */
> -  if (flag_lto)
> +  if (flag_generate_lto)
>      lto_streamer_hooks_init ();
>  
>    /* Don't run the IPA passes if there was any error or sorry messages.  */
> diff --git a/gcc/context.c b/gcc/context.c
> index 5339e28..9279be4 100644
> --- a/gcc/context.c
> +++ b/gcc/context.c
> @@ -30,6 +30,8 @@ gcc::context *g;
>  
>  gcc::context::context ()
>  {
> +  have_offload = false;
> +
>    /* The pass manager's constructor uses the dump manager (to set up
>       dumps for the various passes), so the dump manager must be set up
>       before the pass manager.  */
> diff --git a/gcc/context.h b/gcc/context.h
> index b8fb439..689ae5a 100644
> --- a/gcc/context.h
> +++ b/gcc/context.h
> @@ -33,6 +33,9 @@ class context
>  public:
>    context ();
>  
> +  /* The flag shows if there are symbols to be streamed for offloading.  */
> +  bool have_offload;
> +
>    /* Pass-management.  */
>  
>    pass_manager *get_passes () { gcc_assert (m_passes); return m_passes; }
> diff --git a/gcc/ipa-inline-analysis.c b/gcc/ipa-inline-analysis.c
> index 7da02cd..6cb2057 100644
> --- a/gcc/ipa-inline-analysis.c
> +++ b/gcc/ipa-inline-analysis.c
> @@ -4021,7 +4021,7 @@ inline_generate_summary (void)
>  
>    /* When not optimizing, do not bother to analyze.  Inlining is still done
>       because edge redirection needs to happen there.  */
> -  if (!optimize && !flag_lto && !flag_wpa)
> +  if (!optimize && !flag_generate_lto && !flag_wpa)
>      return;
>  
>    function_insertion_hook_holder =
> @@ -4336,11 +4336,6 @@ void
>  inline_free_summary (void)
>  {
>    struct cgraph_node *node;
> -  if (!inline_edge_summary_vec.exists ())
> -    return;
> -  FOR_EACH_DEFINED_FUNCTION (node)
> -    if (!node->alias)
> -      reset_inline_summary (node);
>    if (function_insertion_hook_holder)
>      symtab->remove_cgraph_insertion_hook (function_insertion_hook_holder);
>    function_insertion_hook_holder = NULL;
> @@ -4356,6 +4351,11 @@ inline_free_summary (void)
>    if (edge_duplication_hook_holder)
>      symtab->remove_edge_duplication_hook (edge_duplication_hook_holder);
>    edge_duplication_hook_holder = NULL;
> +  if (!inline_edge_summary_vec.exists ())
> +    return;
> +  FOR_EACH_DEFINED_FUNCTION (node)
> +    if (!node->alias)
> +      reset_inline_summary (node);
>    vec_free (inline_summary_vec);
>    inline_edge_summary_vec.release ();
>    if (edge_predicate_pool)
> diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
> index 3071f0c..45655ba 100644
> --- a/gcc/lto-cgraph.c
> +++ b/gcc/lto-cgraph.c
> @@ -326,6 +326,11 @@ referenced_from_other_partition_p (symtab_node *node, lto_symtab_encoder_t encod
>  
>    for (i = 0; node->iterate_referring (i, ref); i++)
>      {
> +      /* Ignore references from non-offloadable nodes while streaming NODE into
> +	 offload LTO section.  */
> +      if (!ref->referring->need_lto_streaming)
> +	continue;
> +
>        if (ref->referring->in_other_partition
>            || !lto_symtab_encoder_in_partition_p (encoder, ref->referring))
>  	return true;
> @@ -344,9 +349,16 @@ reachable_from_other_partition_p (struct cgraph_node *node, lto_symtab_encoder_t
>    if (node->global.inlined_to)
>      return false;
>    for (e = node->callers; e; e = e->next_caller)
> -    if (e->caller->in_other_partition
> -	|| !lto_symtab_encoder_in_partition_p (encoder, e->caller))
> -      return true;
> +    {
> +      /* Ignore references from non-offloadable nodes while streaming NODE into
> +	 offload LTO section.  */
> +      if (!e->caller->need_lto_streaming)
> +	continue;
> +
> +      if (e->caller->in_other_partition
> +	  || !lto_symtab_encoder_in_partition_p (encoder, e->caller))
> +	return true;
> +    }
>    return false;
>  }
>  
> @@ -808,6 +820,16 @@ create_references (lto_symtab_encoder_t encoder, symtab_node *node)
>        lto_symtab_encoder_encode (encoder, ref->referred);
>  }
>  
> +/* Select what needs to be streamed out.  In regular lto mode stream everything.
> +   In offload lto mode stream only nodes marked as offloadable.  */
> +void
> +select_what_to_stream (bool offload_lto_mode)
> +{
> +  struct symtab_node *snode;
> +  FOR_EACH_SYMBOL (snode)
> +    snode->need_lto_streaming = !offload_lto_mode || snode->offloadable;
> +}
> +
>  /* Find all symbols we want to stream into given partition and insert them
>     to encoders.
>  
> @@ -834,6 +856,8 @@ compute_ltrans_boundary (lto_symtab_encoder_t in_encoder)
>         !lsei_end_p (lsei); lsei_next_function_in_partition (&lsei))
>      {
>        struct cgraph_node *node = lsei_cgraph_node (lsei);
> +      if (!node->need_lto_streaming)
> +	continue;
>        add_node_to (encoder, node, true);
>        lto_set_symtab_encoder_in_partition (encoder, node);
>        create_references (encoder, node);
> @@ -850,6 +874,8 @@ compute_ltrans_boundary (lto_symtab_encoder_t in_encoder)
>      {
>        varpool_node *vnode = lsei_varpool_node (lsei);
>  
> +      if (!vnode->need_lto_streaming)
> +	continue;
>        lto_set_symtab_encoder_in_partition (encoder, vnode);
>        lto_set_symtab_encoder_encode_initializer (encoder, vnode);
>        create_references (encoder, vnode);
> diff --git a/gcc/lto-section-names.h b/gcc/lto-section-names.h
> index cb75230..f5dbed2 100644
> --- a/gcc/lto-section-names.h
> +++ b/gcc/lto-section-names.h
> @@ -25,6 +25,11 @@ along with GCC; see the file COPYING3.  If not see
>     name for the functions and static_initializers.  For other types of
>     sections a '.' and the section type are appended.  */
>  #define LTO_SECTION_NAME_PREFIX ".gnu.lto_"
> +#define OFFLOAD_SECTION_NAME_PREFIX ".gnu.offload_lto_"
> +
> +/* Can be either OFFLOAD_SECTION_NAME_PREFIX when we stream IR for offload
> +   compiler, or LTO_SECTION_NAME_PREFIX for LTO case.  */
> +extern const char *section_name_prefix;
>  
>  /* Segment name for LTO sections.  This is only used for Mach-O.  */
>  
> diff --git a/gcc/lto-streamer.c b/gcc/lto-streamer.c
> index cb647bd..79c137d 100644
> --- a/gcc/lto-streamer.c
> +++ b/gcc/lto-streamer.c
> @@ -56,6 +56,7 @@ struct lto_stats_d lto_stats;
>  static bitmap_obstack lto_obstack;
>  static bool lto_obstack_initialized;
>  
> +const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
>  
>  /* Return a string representing LTO tag TAG.  */
>  
> @@ -185,7 +186,7 @@ lto_get_section_name (int section_type, const char *name, struct lto_file_decl_d
>      sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
>    else
>      sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false)); 
> -  return concat (LTO_SECTION_NAME_PREFIX, sep, add, post, NULL);
> +  return concat (section_name_prefix, sep, add, post, NULL);
>  }
>  
>  
> diff --git a/gcc/lto-streamer.h b/gcc/lto-streamer.h
> index 63e4b32..0b3fb6a 100644
> --- a/gcc/lto-streamer.h
> +++ b/gcc/lto-streamer.h
> @@ -832,6 +832,7 @@ bool referenced_from_this_partition_p (symtab_node *,
>  bool reachable_from_this_partition_p (struct cgraph_node *,
>  				      lto_symtab_encoder_t);
>  lto_symtab_encoder_t compute_ltrans_boundary (lto_symtab_encoder_t encoder);
> +void select_what_to_stream (bool);
>  
>  
>  /* In lto-symtab.c.  */
> diff --git a/gcc/lto/lto-object.c b/gcc/lto/lto-object.c
> index 28b459c..637d1f2 100644
> --- a/gcc/lto/lto-object.c
> +++ b/gcc/lto/lto-object.c
> @@ -238,8 +238,7 @@ lto_obj_add_section (void *data, const char *name, off_t offset,
>    void **slot;
>    struct lto_section_list *list = loasd->list;
>  
> -  if (strncmp (name, LTO_SECTION_NAME_PREFIX,
> -	       strlen (LTO_SECTION_NAME_PREFIX)) != 0)
> +  if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
>      return 1;
>  
>    new_name = xstrdup (name);
> diff --git a/gcc/lto/lto-partition.c b/gcc/lto/lto-partition.c
> index b647275..6290b23 100644
> --- a/gcc/lto/lto-partition.c
> +++ b/gcc/lto/lto-partition.c
> @@ -928,6 +928,8 @@ lto_promote_cross_file_statics (void)
>  
>    gcc_assert (flag_wpa);
>  
> +  select_what_to_stream (false);
> +
>    /* First compute boundaries.  */
>    n_sets = ltrans_partitions.length ();
>    for (i = 0; i < n_sets; i++)
> diff --git a/gcc/lto/lto.c b/gcc/lto/lto.c
> index 1234cee..0451e71 100644
> --- a/gcc/lto/lto.c
> +++ b/gcc/lto/lto.c
> @@ -2127,7 +2127,7 @@ lto_section_with_id (const char *name, unsigned HOST_WIDE_INT *id)
>  {
>    const char *s;
>  
> -  if (strncmp (name, LTO_SECTION_NAME_PREFIX, strlen (LTO_SECTION_NAME_PREFIX)))
> +  if (strncmp (name, section_name_prefix, strlen (section_name_prefix)))
>      return 0;
>    s = strrchr (name, '.');
>    return s && sscanf (s, "." HOST_WIDE_INT_PRINT_HEX_PURE, id) == 1;
> @@ -2902,6 +2902,10 @@ read_cgraph_and_symbols (unsigned nfiles, const char **fnames)
>  
>    timevar_push (TV_IPA_LTO_DECL_IN);
>  
> +#ifdef ACCEL_COMPILER
> +    section_name_prefix = OFFLOAD_SECTION_NAME_PREFIX;
> +#endif
> +
>    real_file_decl_data
>      = decl_data = ggc_cleared_vec_alloc<lto_file_decl_data_ptr> (nfiles + 1);
>    real_file_count = nfiles;
> diff --git a/gcc/omp-low.c b/gcc/omp-low.c
> index fe9bf80..1404b5e 100644
> --- a/gcc/omp-low.c
> +++ b/gcc/omp-low.c
> @@ -81,6 +81,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "tree-nested.h"
>  #include "tree-eh.h"
>  #include "cilk.h"
> +#include "context.h"
>  
>  
>  /* Lowering of OpenMP parallel and workshare constructs proceeds in two
> @@ -268,6 +269,16 @@ is_parallel_ctx (omp_context *ctx)
>  }
>  
>  
> +/* Return true if CTX is for an omp target region.  */
> +
> +static inline bool
> +is_targetreg_ctx (omp_context *ctx)
> +{
> +  return gimple_code (ctx->stmt) == GIMPLE_OMP_TARGET
> +	 && gimple_omp_target_kind (ctx->stmt) == GF_OMP_TARGET_KIND_REGION;
> +}
> +
> +
>  /* Return true if CTX is for an omp task.  */
>  
>  static inline bool
> @@ -1933,26 +1944,19 @@ create_omp_child_function (omp_context *ctx, bool task_copy)
>    DECL_EXTERNAL (decl) = 0;
>    DECL_CONTEXT (decl) = NULL_TREE;
>    DECL_INITIAL (decl) = make_node (BLOCK);
> -  bool target_p = false;
> -  if (lookup_attribute ("omp declare target",
> -			DECL_ATTRIBUTES (current_function_decl)))
> -    target_p = true;
> +  if (cgraph_node::get (current_function_decl)->offloadable)
> +    cgraph_node::get_create (decl)->offloadable = 1;
>    else
>      {
>        omp_context *octx;
>        for (octx = ctx; octx; octx = octx->outer)
> -	if (gimple_code (octx->stmt) == GIMPLE_OMP_TARGET
> -	    && gimple_omp_target_kind (octx->stmt)
> -	       == GF_OMP_TARGET_KIND_REGION)
> +	if (is_targetreg_ctx (octx))
>  	  {
> -	    target_p = true;
> +	    cgraph_node::get_create (decl)->offloadable = 1;
> +	    g->have_offload = true;
>  	    break;
>  	  }
>      }
> -  if (target_p)
> -    DECL_ATTRIBUTES (decl)
> -      = tree_cons (get_identifier ("omp declare target"),
> -		   NULL_TREE, DECL_ATTRIBUTES (decl));
>  
>    t = build_decl (DECL_SOURCE_LOCATION (decl),
>  		  RESULT_DECL, NULL_TREE, void_type_node);
> @@ -2658,8 +2662,7 @@ check_omp_nesting_restrictions (gimple stmt, omp_context *ctx)
>        break;
>      case GIMPLE_OMP_TARGET:
>        for (; ctx != NULL; ctx = ctx->outer)
> -	if (gimple_code (ctx->stmt) == GIMPLE_OMP_TARGET
> -	    && gimple_omp_target_kind (ctx->stmt) == GF_OMP_TARGET_KIND_REGION)
> +	if (is_targetreg_ctx (ctx))
>  	  {
>  	    const char *name;
>  	    switch (gimple_omp_target_kind (stmt))
> @@ -8276,6 +8279,7 @@ expand_omp_target (struct omp_region *region)
>    if (kind == GF_OMP_TARGET_KIND_REGION)
>      {
>        unsigned srcidx, dstidx, num;
> +      struct cgraph_node *node;
>  
>        /* If the target region needs data sent from the parent
>  	 function, then the very first statement (except possible
> @@ -8407,6 +8411,11 @@ expand_omp_target (struct omp_region *region)
>        push_cfun (child_cfun);
>        cgraph_edge::rebuild_edges ();
>  
> +      /* Prevent IPA from removing child_fn as unreachable, since there are no
> +	 refs from the parent function to child_fn in offload LTO mode.  */
> +      node = cgraph_node::get (child_fn);
> +      node->mark_force_output ();
> +
>        /* Some EH regions might become dead, see PR34608.  If
>  	 pass_cleanup_cfg isn't the first pass to happen with the
>  	 new child, these dead EH edges might cause problems.
> @@ -9277,6 +9286,17 @@ lower_omp_critical (gimple_stmt_iterator *gsi_p, omp_context *ctx)
>  	  DECL_COMMON (decl) = 1;
>  	  DECL_ARTIFICIAL (decl) = 1;
>  	  DECL_IGNORED_P (decl) = 1;
> +
> +	  /* If '#pragma omp critical' is inside target region, the symbol must
> +	     be marked for offloading.  */
> +	  omp_context *octx;
> +	  for (octx = ctx->outer; octx; octx = octx->outer)
> +	    if (is_targetreg_ctx (octx))
> +	      {
> +		varpool_node::get_create (decl)->offloadable = 1;
> +		break;
> +	      }
> +
>  	  varpool_node::finalize_decl (decl);
>  
>  	  splay_tree_insert (critical_name_mutexes, (splay_tree_key) name,
> diff --git a/gcc/passes.c b/gcc/passes.c
> index 8432de8..bd4031b 100644
> --- a/gcc/passes.c
> +++ b/gcc/passes.c
> @@ -2303,7 +2303,7 @@ ipa_write_summaries_1 (lto_symtab_encoder_t encoder)
>  /* Write out summaries for all the nodes in the callgraph.  */
>  
>  void
> -ipa_write_summaries (void)
> +ipa_write_summaries (bool offload_lto_mode)
>  {
>    lto_symtab_encoder_t encoder;
>    int i, order_pos;
> @@ -2314,6 +2314,8 @@ ipa_write_summaries (void)
>    if (!flag_generate_lto || seen_error ())
>      return;
>  
> +  select_what_to_stream (offload_lto_mode);
> +
>    encoder = lto_symtab_encoder_new (false);
>  
>    /* Create the callgraph set in the same order used in
> @@ -2340,15 +2342,16 @@ ipa_write_summaries (void)
>  	  renumber_gimple_stmt_uids ();
>  	  pop_cfun ();
>  	}
> -      if (node->definition)
> +      if (node->definition && node->need_lto_streaming)
>          lto_set_symtab_encoder_in_partition (encoder, node);
>      }
>  
>    FOR_EACH_DEFINED_FUNCTION (node)
> -    if (node->alias)
> +    if (node->alias && node->need_lto_streaming)
>        lto_set_symtab_encoder_in_partition (encoder, node);
>    FOR_EACH_DEFINED_VARIABLE (vnode)
> -    lto_set_symtab_encoder_in_partition (encoder, vnode);
> +    if (vnode->need_lto_streaming)
> +      lto_set_symtab_encoder_in_partition (encoder, vnode);
>  
>    ipa_write_summaries_1 (compute_ltrans_boundary (encoder));
>  
> diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
> index 3db1a08..cbed6e7 100644
> --- a/gcc/tree-pass.h
> +++ b/gcc/tree-pass.h
> @@ -594,7 +594,7 @@ extern void pass_fini_dump_file (opt_pass *);
>  extern const char *get_current_pass_name (void);
>  extern void print_current_pass (FILE *);
>  extern void debug_pass (void);
> -extern void ipa_write_summaries (void);
> +extern void ipa_write_summaries (bool);
>  extern void ipa_write_optimization_summaries (struct lto_symtab_encoder_d *);
>  extern void ipa_read_summaries (void);
>  extern void ipa_read_optimization_summaries (void);
> diff --git a/gcc/varpool.c b/gcc/varpool.c
> index 50b5665..c508bf9 100644
> --- a/gcc/varpool.c
> +++ b/gcc/varpool.c
> @@ -40,6 +40,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "gimple.h"
>  #include "lto-streamer.h"
>  #include "hash-set.h"
> +#include "context.h"
>  
>  const char * const tls_model_names[]={"none", "tls-emulated", "tls-real",
>  				      "tls-global-dynamic", "tls-local-dynamic",
> @@ -155,6 +156,14 @@ varpool_node::get_create (tree decl)
>  
>    node = varpool_node::create_empty ();
>    node->decl = decl;
> +
> +  if (flag_openmp
> +      && lookup_attribute ("omp declare target", DECL_ATTRIBUTES (decl)))
> +    {
> +      node->offloadable = 1;
> +      g->have_offload = true;
> +    }
> +
>    node->register_symbol ();
>    return node;
>  }
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendoerffer, HRB 21284
(AG Nuernberg)
Maxfeldstrasse 5, 90409 Nuernberg, Germany