Simplify LTO section format.

2019-07-22  Martin Liska  <mliska@suse.cz>

	* lto-section-in.c (lto_get_section_data):
	Use new function get_compression.
	* lto-streamer-out.c (produce_lto_section): Use
	set_compression to encode compression algorithm.
	* lto-streamer.h (struct lto_section): Do not
	use bitfields in the format.

From-SVN: r273661

gcc/ChangeLog

 2019-07-22  Martin Liska  <mliska@suse.cz>
 
+	* lto-section-in.c (lto_get_section_data):
+	Use new function get_compression.
+	* lto-streamer-out.c (produce_lto_section): Use
+	set_compression to encode compression algorithm.
+	* lto-streamer.h (struct lto_section): Do not
+	use bitfields in the format.
+
+2019-07-22  Martin Liska  <mliska@suse.cz>
+
 	PR driver/91172
 	* opts-common.c (decode_cmdline_option): Decode
 	argument of -Werror and check it for a wrong language.

gcc/lto-section-in.c

@@ -161,7 +161,8 @@ lto_get_section_data (struct lto_file_decl_data *file_data,
 
       stream = lto_start_uncompression (lto_append_data, &buffer);
       lto_uncompress_block (stream, data, *len);
-      lto_end_uncompression (stream, file_data->lto_section_header.compression);
+      lto_end_uncompression (stream,
+			     file_data->lto_section_header.get_compression ());
 
       *len = buffer.length - header_length;
       data = buffer.data + header_length;

gcc/lto-streamer-out.c

@@ -2403,7 +2403,8 @@ produce_lto_section ()
 
   bool slim_object = flag_generate_lto && !flag_fat_lto_objects;
   lto_section s
-    = { LTO_major_version, LTO_minor_version, slim_object, compression, 0 };
+    = { LTO_major_version, LTO_minor_version, slim_object, 0 };
+  s.set_compression (compression);
   lto_write_data (&s, sizeof s);
   lto_end_section ();
   destroy_output_block (ob);

gcc/lto-streamer.h

@@ -394,9 +394,22 @@ struct lto_section
 {
   int16_t major_version;
   int16_t minor_version;
-  unsigned char slim_object: 1;
-  lto_compression compression: 4;
-  int32_t reserved0: 27;
+  unsigned char slim_object;
+
+  /* Flags is a private field that is not defined publicly.  */
+  uint16_t flags;
+
+  /* Set compression to FLAGS.  */
+  inline void set_compression (lto_compression c)
+  {
+    flags = c;
+  }
+
+  /* Get compression from FLAGS.  */
+  inline lto_compression get_compression ()
+  {
+    return (lto_compression) flags;
+  }
 };
 
 STATIC_ASSERT (sizeof (lto_section) == 8);