[PATCH 2/7] OpenMP 4.0 offloading infrastructure: LTO streaming.

gcc/
	* cgraph.c: Include context.h.
	(cgraph_node::create): Set node->offloadable and g->have_offload if
	decl have "omp declare target" attribute.
	* cgraph.h (symtab_node): Add need_lto_streaming and offloadable flags.
	* cgraphunit.c: Include lto-section-names.h.
	(ipa_passes): Call ipa_write_summaries if there is something to write to
	OFFLOAD_SECTION_NAME_PREFIX sections.
	(symbol_table::compile): Set flag_generate_lto if there is something to
	offload.
	Replace flag_lto with flag_generate_lto before lto_streamer_hooks_init.
	* context.c (gcc::context::context): Initialize have_offload with false.
	* context.h (class context): Add have_offload flag.
	* ipa-inline-analysis.c (inline_generate_summary): Do not exit under
	flag_generate_lto.
	(inline_free_summary): Always remove hooks.
	* lto-cgraph.c (referenced_from_other_partition_p): Ignore references
	from non-offloadable nodes while streaming a node into offload section.
	(reachable_from_other_partition_p): Likewise.
	(select_what_to_stream): New function.
	(compute_ltrans_boundary): Do not call
	lto_set_symtab_encoder_in_partition if the node should not be streamed.
	* lto-section-names.h (OFFLOAD_SECTION_NAME_PREFIX): Define.
	(section_name_prefix): Declare.
	* lto-streamer.c (section_name_prefix): New variable.
	(lto_get_section_name): Use section_name_prefix instead of
	LTO_SECTION_NAME_PREFIX.
	* lto-streamer.h (select_what_to_stream): Declare.
	* omp-low.c: Include context.h.
	(is_targetreg_ctx): New function.
	(scan_sharing_clauses): Use offloadable flag, instead of an attribute.
	(create_omp_child_function, check_omp_nesting_restrictions): Use new
	is_targetreg_ctx function.  Replace usage of "omp declare target"
	attribute with a cgraph_node flag offloadable.
	(expand_omp_target): Set mark_force_output for offloadable functions.
	(lower_omp_critical): Set offloadable flag for omp critical symbol.
	* passes.c (ipa_write_summaries): New argument offload_lto_mode.  Call
	select_what_to_stream.  Do not call lto_set_symtab_encoder_in_partition
	if the node should not be streamed out.
	* tree-pass.h (ipa_write_summaries): New bool argument.
	* varpool.c: Include context.h.
	(varpool_node::get_create): Set node->offloadable and g->have_offload if
	decl have "omp declare target" attribute.

gcc/lto/
	* lto-object.c (lto_obj_add_section): Use section_name_prefix instead of
	LTO_SECTION_NAME_PREFIX.
	* lto-partition.c (lto_promote_cross_file_statics): Call
	select_what_to_stream.
	* lto.c (lto_section_with_id): Use section_name_prefix instead of
	LTO_SECTION_NAME_PREFIX.
	(read_cgraph_and_symbols): Read OFFLOAD_SECTION_NAME_PREFIX sections, if
	being built as an offload compiler.

Co-Authored-By: Andrey Turetskiy <andrey.turetskiy@intel.com>
Co-Authored-By: Bernd Schmidt <bernds@codesourcery.com>
Co-Authored-By: Michael Zolotukhin <michael.v.zolotukhin@intel.com>

From-SVN: r217486

1 files changed, 29 insertions, 3 deletions

diff --git a/gcc/lto-cgraph.c b/gcc/lto-cgraph.c
index da1f0e4..fc8410c 100644
--- a/gcc/lto-cgraph.c
+++ b/gcc/lto-cgraph.c
@@ -330,6 +330,11 @@ 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;
@@ -348,9 +353,16 @@ 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;
 }
 
@@ -818,6 +830,16 @@ 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.
 
@@ -844,6 +866,8 @@ 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);
@@ -860,6 +884,8 @@ 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);