[PATCH 1/2] LTO: split out writing of top level asm nodes

["Jan Beulich" <JBeulich at suse dot com>]

Split out LTO's writing of top level asm nodes in preparation of extending
what needs to be written out when top level asm-s get enhanced to accept a
limited set of input operands.

gcc/
2011-09-30  Jan Beulich  <jbeulich@suse.com>

	* lto-cgraph.c (output_cgraph): Remove processing of 'cgraph_asm_nodes',
	call lto_output_toplevel_asms() instead.
	(input_cgraph_1): Remove loop calling cgraph_add_asm_node(), call
	lto_input_toplevel_asms() instead.
	* lto-section-in.c (lto_section_name): Add "asm" entry.
	* lto-streamer-in.c (lto_input_toplevel_asms): New.
	* lto-streamer-out.c (lto_output_toplevel_asms): New.
	* lto-streamer.h (LTO_minor_version): Bump.
	(enum lto_section_type): Add LTO_section_asm.
	(struct lto_asm_header): New.
	(lto_input_toplevel_asms, lto_output_toplevel_asms): Declare.
	* tree-streamer.h (streamer_write_string_cst): Declare.
	* tree-streamer-out.c (write_string_cst): Rename to
	streamer_write_string_cst and make global.
	(streamer_write_tree_header): Adjust call to renamed function.

--- 2011-09-29.orig/gcc/lto-cgraph.c	2011-09-28 10:56:01.000000000 +0200
+++ 2011-09-29/gcc/lto-cgraph.c	2011-09-29 15:07:23.000000000 +0200
@@ -817,7 +817,6 @@ output_cgraph (cgraph_node_set set, varp
   int i, n_nodes;
   lto_cgraph_encoder_t encoder;
   lto_varpool_encoder_t varpool_encoder;
-  struct cgraph_asm_node *can;
   static bool asm_nodes_output = false;
 
   if (flag_wpa)
@@ -854,6 +853,8 @@ output_cgraph (cgraph_node_set set, varp
 
   streamer_write_uhwi_stream (ob->main_stream, 0);
 
+  lto_destroy_simple_output_block (ob);
+
   /* Emit toplevel asms.
      When doing WPA we must output every asm just once.  Since we do not partition asm
      nodes at all, output them to first output.  This is kind of hack, but should work
@@ -861,19 +862,9 @@ output_cgraph (cgraph_node_set set, varp
   if (!asm_nodes_output)
     {
       asm_nodes_output = true;
-      for (can = cgraph_asm_nodes; can; can = can->next)
-	{
-	  int len = TREE_STRING_LENGTH (can->asm_str);
-	  streamer_write_uhwi_stream (ob->main_stream, len);
-	  for (i = 0; i < len; ++i)
-	    streamer_write_char_stream (ob->main_stream,
-					TREE_STRING_POINTER (can->asm_str)[i]);
-	}
+      lto_output_toplevel_asms ();
     }
 
-  streamer_write_uhwi_stream (ob->main_stream, 0);
-
-  lto_destroy_simple_output_block (ob);
   output_varpool (set, vset);
   output_refs (set, vset, encoder, varpool_encoder);
 }
@@ -1185,7 +1176,6 @@ input_cgraph_1 (struct lto_file_decl_dat
   VEC(cgraph_node_ptr, heap) *nodes = NULL;
   struct cgraph_node *node;
   unsigned i;
-  unsigned HOST_WIDE_INT len;
 
   tag = streamer_read_enum (ib, LTO_cgraph_tags, LTO_cgraph_last_tag);
   while (tag)
@@ -1206,18 +1196,8 @@ input_cgraph_1 (struct lto_file_decl_dat
       tag = streamer_read_enum (ib, LTO_cgraph_tags, LTO_cgraph_last_tag);
     }
 
-  /* Input toplevel asms.  */
-  len = streamer_read_uhwi (ib);
-  while (len)
-    {
-      char *str = (char *)xmalloc (len + 1);
-      for (i = 0; i < len; ++i)
-	str[i] = streamer_read_uchar (ib);
-      cgraph_add_asm_node (build_string (len, str));
-      free (str);
+  lto_input_toplevel_asms (file_data);
 
-      len = streamer_read_uhwi (ib);
-    }
   /* AUX pointers should be all non-zero for nodes read from the stream.  */
 #ifdef ENABLE_CHECKING
   FOR_EACH_VEC_ELT (cgraph_node_ptr, nodes, i, node)
--- 2011-09-29.orig/gcc/lto-section-in.c	2011-09-28 10:56:01.000000000 +0200
+++ 2011-09-29/gcc/lto-section-in.c	2011-09-29 15:07:23.000000000 +0200
@@ -53,6 +53,7 @@ const char *lto_section_name[LTO_N_SECTI
   "cgraph",
   "vars",
   "refs",
+  "asm",
   "jmpfuncs",
   "pureconst",
   "reference",
--- 2011-09-29.orig/gcc/lto-streamer-in.c	2011-09-28 10:56:01.000000000 +0200
+++ 2011-09-29/gcc/lto-streamer-in.c	2011-09-29 15:07:23.000000000 +0200
@@ -1141,6 +1141,47 @@ lto_input_tree (struct lto_input_block *
 }
 
 
+/* Input toplevel asms.  */
+
+void
+lto_input_toplevel_asms (struct lto_file_decl_data *file_data)
+{
+  size_t len;
+  const char *data = lto_get_section_data (file_data, LTO_section_asm,
+					   NULL, &len);
+  const struct lto_asm_header *header = (const struct lto_asm_header *) data;
+  int32_t string_offset;
+  struct data_in *data_in;
+  struct lto_input_block ib;
+  tree str;
+
+  if (! data)
+    return;
+
+  string_offset = sizeof (*header) + header->main_size;
+
+  LTO_INIT_INPUT_BLOCK (ib,
+			data + sizeof (*header),
+			0,
+			header->main_size);
+
+  data_in = lto_data_in_create (file_data, data + string_offset,
+				header->string_size, NULL);
+
+  /* Make sure the file was generated by the exact same compiler.  */
+  lto_check_version (header->lto_header.major_version,
+		     header->lto_header.minor_version);
+
+  while ((str = streamer_read_string_cst (data_in, &ib)))
+    cgraph_add_asm_node (str);
+
+  clear_line_info (data_in);
+  lto_data_in_delete (data_in);
+
+  lto_free_section_data (file_data, LTO_section_asm, NULL, data, len);
+}
+
+
 /* Initialization for the LTO reader.  */
 
 void
--- 2011-09-29.orig/gcc/lto-streamer-out.c	2011-09-28 10:56:01.000000000 +0200
+++ 2011-09-29/gcc/lto-streamer-out.c	2011-09-29 15:07:23.000000000 +0200
@@ -934,6 +934,61 @@ output_unreferenced_globals (cgraph_node
 }
 
 
+/* Emit toplevel asms.  */
+
+void
+lto_output_toplevel_asms (void)
+{
+  struct output_block *ob;
+  struct cgraph_asm_node *can;
+  char *section_name;
+  struct lto_output_stream *header_stream;
+  struct lto_asm_header header;
+
+  if (! cgraph_asm_nodes)
+    return;
+
+  ob = create_output_block (LTO_section_asm);
+
+  /* Make string 0 be a NULL string.  */
+  streamer_write_char_stream (ob->string_stream, 0);
+
+  for (can = cgraph_asm_nodes; can; can = can->next)
+    streamer_write_string_cst (ob, ob->main_stream, can->asm_str);
+
+  streamer_write_string_cst (ob, ob->main_stream, NULL_TREE);
+
+  section_name = lto_get_section_name (LTO_section_asm, NULL, NULL);
+  lto_begin_section (section_name, !flag_wpa);
+  free (section_name);
+
+  /* The entire header stream is computed here.  */
+  memset (&header, 0, sizeof (header));
+
+  /* Write the header.  */
+  header.lto_header.major_version = LTO_major_version;
+  header.lto_header.minor_version = LTO_minor_version;
+  header.lto_header.section_type = LTO_section_asm;
+
+  header.main_size = ob->main_stream->total_size;
+  header.string_size = ob->string_stream->total_size;
+
+  header_stream = XCNEW (struct lto_output_stream);
+  lto_output_data_stream (header_stream, &header, sizeof (header));
+  lto_write_stream (header_stream);
+  free (header_stream);
+
+  /* Put all of the gimple and the string table out the asm file as a
+     block of text.  */
+  lto_write_stream (ob->main_stream);
+  lto_write_stream (ob->string_stream);
+
+  lto_end_section ();
+
+  destroy_output_block (ob);
+}
+
+
 /* Copy the function body of NODE without deserializing. */
 
 static void
--- 2011-09-29.orig/gcc/lto-streamer.h	2011-09-28 10:56:01.000000000 +0200
+++ 2011-09-29/gcc/lto-streamer.h	2011-09-29 15:07:23.000000000 +0200
@@ -142,7 +142,7 @@ along with GCC; see the file COPYING3.  
 #define LTO_SECTION_NAME_PREFIX         ".gnu.lto_"
 
 #define LTO_major_version 2
-#define LTO_minor_version 0
+#define LTO_minor_version 1
 
 typedef unsigned char	lto_decl_flags_t;
 
@@ -238,6 +238,7 @@ enum lto_section_type
   LTO_section_cgraph,
   LTO_section_varpool,
   LTO_section_refs,
+  LTO_section_asm,
   LTO_section_jump_functions,
   LTO_section_ipa_pure_const,
   LTO_section_ipa_reference,
@@ -387,6 +388,23 @@ struct lto_decl_header
 };
 
 
+/* Structure describing top level asm()s.  */
+struct lto_asm_header
+{
+  /* The header for all types of sections. */
+  struct lto_header lto_header;
+
+  /* Size compressed or 0 if not compressed.  */
+  int32_t compressed_size;
+
+  /* Size of region for expressions, decls, types, etc. */
+  int32_t main_size;
+
+  /* Size of the string table.  */
+  int32_t string_size;
+};
+
+
 /* Statistics gathered during LTO, WPA and LTRANS.  */
 struct lto_stats_d
 {
@@ -789,6 +807,7 @@ extern void lto_input_function_body (str
 				     const char *);
 extern void lto_input_constructors_and_inits (struct lto_file_decl_data *,
 					      const char *);
+extern void lto_input_toplevel_asms (struct lto_file_decl_data *);
 extern struct data_in *lto_data_in_create (struct lto_file_decl_data *,
 				    const char *, unsigned,
 				    VEC(ld_plugin_symbol_resolution_t,heap) *);
@@ -807,6 +826,7 @@ extern void lto_register_decl_definition
 extern struct output_block *create_output_block (enum lto_section_type);
 extern void destroy_output_block (struct output_block *);
 extern void lto_output_tree (struct output_block *, tree, bool);
+extern void lto_output_toplevel_asms (void);
 extern void produce_asm (struct output_block *ob, tree fn);
 void lto_output_decl_state_streams (struct output_block *,
 				    struct lto_out_decl_state *);
--- 2011-09-29.orig/gcc/tree-streamer.h	2011-09-28 10:56:01.000000000 +0200
+++ 2011-09-29/gcc/tree-streamer.h	2011-09-29 15:07:23.000000000 +0200
@@ -75,6 +75,8 @@ tree streamer_read_integer_cst (struct l
 struct bitpack_d streamer_read_tree_bitfields (struct lto_input_block *, tree);
 
 /* In tree-streamer-out.c.  */
+void streamer_write_string_cst (struct output_block *,
+				struct lto_output_stream *, tree);
 void streamer_write_chain (struct output_block *, tree, bool);
 void streamer_write_tree_header (struct output_block *, tree);
 void streamer_pack_tree_bitfields (struct bitpack_d *, tree);
--- 2011-09-29.orig/gcc/tree-streamer-out.c	2011-09-28 10:56:01.000000000 +0200
+++ 2011-09-29/gcc/tree-streamer-out.c	2011-09-29 15:07:23.000000000 +0200
@@ -31,11 +31,16 @@ along with GCC; see the file COPYING3.  
 /* Output the STRING constant to the string
    table in OB.  Then put the index onto the INDEX_STREAM.  */
 
-static void
-write_string_cst (struct output_block *ob,
-		   struct lto_output_stream *index_stream,
-		   tree string)
+void
+streamer_write_string_cst (struct output_block *ob,
+			   struct lto_output_stream *index_stream,
+			   tree string)
 {
+  if (! string)
+    {
+      streamer_write_char_stream (index_stream, 0);
+      return;
+    }
   streamer_write_string_with_length (ob, index_stream,
 				     TREE_STRING_POINTER (string),
 				     TREE_STRING_LENGTH (string),
@@ -866,7 +871,7 @@ streamer_write_tree_header (struct outpu
   /* The text in strings and identifiers are completely emitted in
      the header.  */
   if (CODE_CONTAINS_STRUCT (code, TS_STRING))
-    write_string_cst (ob, ob->main_stream, expr);
+    streamer_write_string_cst (ob, ob->main_stream, expr);
   else if (CODE_CONTAINS_STRUCT (code, TS_IDENTIFIER))
     write_identifier (ob, ob->main_stream, expr);
   else if (CODE_CONTAINS_STRUCT (code, TS_VEC))