gcc/lto-streamer.cc

   1 /* Miscellaneous utilities for GIMPLE streaming.  Things that are used
   2    in both input and output are here.
   3
   4    Copyright (C) 2009-2025 Free Software Foundation, Inc.
   5    Contributed by Doug Kwan <dougkwan@google.com>
   6
   7 This file is part of GCC.
   8
   9 GCC is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 3, or (at your option) any later
  12 version.
  13
  14 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GCC; see the file COPYING3.  If not see
  21 <http://www.gnu.org/licenses/>.  */
  22
  23 #include "config.h"
  24 #include "system.h"
  25 #include "coretypes.h"
  26 #include "backend.h"
  27 #include "tree.h"
  28 #include "gimple.h"
  29 #include "tree-streamer.h"
  30 #include "cgraph.h"
  31 #include "lto-streamer.h"
  32 #include "toplev.h"
  33 #include "lto-section-names.h"
  34
  35 /* Statistics gathered during LTO, WPA and LTRANS.  */
  36 struct lto_stats_d lto_stats;
  37
  38 const char *section_name_prefix = LTO_SECTION_NAME_PREFIX;
  39 /* Set when streaming LTO for offloading compiler.  */
  40 bool lto_stream_offload_p;
  41
  42 FILE *streamer_dump_file;
  43
  44 /* Return a string representing LTO tag TAG.  */
  45
  46 const char *
  47 lto_tag_name (enum LTO_tags tag)
  48 {
  49   if (lto_tag_is_tree_code_p (tag))
  50     {
  51       /* For tags representing tree nodes, return the name of the
  52          associated tree code.  */
  53       return get_tree_code_name (lto_tag_to_tree_code (tag));
  54     }
  55
  56   if (lto_tag_is_gimple_code_p (tag))
  57     {
  58       /* For tags representing gimple statements, return the name of
  59          the associated gimple code.  */
  60       return gimple_code_name[lto_tag_to_gimple_code (tag)];
  61     }
  62
  63   switch (tag)
  64     {
  65     case LTO_null:
  66       return "LTO_null";
  67     case LTO_bb0:
  68       return "LTO_bb0";
  69     case LTO_bb1:
  70       return "LTO_bb1";
  71     case LTO_eh_region:
  72       return "LTO_eh_region";
  73     case LTO_function:
  74       return "LTO_function";
  75     case LTO_eh_table:
  76       return "LTO_eh_table";
  77     case LTO_ert_cleanup:
  78       return "LTO_ert_cleanup";
  79     case LTO_ert_try:
  80       return "LTO_ert_try";
  81     case LTO_ert_allowed_exceptions:
  82       return "LTO_ert_allowed_exceptions";
  83     case LTO_ert_must_not_throw:
  84       return "LTO_ert_must_not_throw";
  85     case LTO_tree_pickle_reference:
  86       return "LTO_tree_pickle_reference";
  87     case LTO_global_stream_ref:
  88       return "LTO_global_sream_ref";
  89     case LTO_ssa_name_ref:
  90       return "LTO_ssa_name_ref";
  91     default:
  92       return "LTO_UNKNOWN";
  93     }
  94 }
  95
  96
  97 /* Get a section name for a particular type or name.  The NAME field
  98    is only used if SECTION_TYPE is LTO_section_function_body. For all
  99    others it is ignored.  The callee of this function is responsible
 100    to free the returned name.  */
 101
 102 char *
 103 lto_get_section_name (int section_type, const char *name,
 104                       int node_order, struct lto_file_decl_data *f)
 105 {
 106   const char *add;
 107   char post[32];
 108   const char *sep;
 109   char *buffer = NULL;
 110
 111   if (section_type == LTO_section_function_body)
 112     {
 113       gcc_assert (name != NULL);
 114       if (name[0] == '*')
 115         name++;
 116
 117       buffer = (char *)xmalloc (strlen (name) + 32);
 118       sprintf (buffer, "%s.%d", name, node_order);
 119
 120       add = buffer;
 121       sep = "";
 122     }
 123   else if (section_type < LTO_N_SECTION_TYPES)
 124     {
 125       add = lto_section_name[section_type];
 126       sep = ".";
 127     }
 128   else
 129     internal_error ("bytecode stream: unexpected LTO section %s", name);
 130
 131   /* Make the section name unique so that ld -r combining sections
 132      doesn't confuse the reader with merged sections.
 133
 134      For options don't add a ID, the option reader cannot deal with them
 135      and merging should be ok here.
 136
 137      LTRANS files (output of wpa, input and output of ltrans) are handled
 138      directly inside of linker/lto-wrapper, so name uniqueness for external
 139      tools is not needed.
 140      Randomness would inhibit incremental LTO.  */
 141   if (section_type == LTO_section_opts || flag_ltrans)
 142     strcpy (post, "");
 143   else if (f != NULL)
 144     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, f->id);
 145   else if (flag_wpa)
 146     strcpy (post, "");
 147   else
 148     sprintf (post, "." HOST_WIDE_INT_PRINT_HEX_PURE, get_random_seed (false));
 149   char *res = concat (section_name_prefix, sep, add, post, NULL);
 150   if (buffer)
 151     free (buffer);
 152   return res;
 153 }
 154
 155
 156 /* Show various memory usage statistics related to LTO.  */
 157
 158 void
 159 print_lto_report (const char *s)
 160 {
 161   unsigned i;
 162
 163   fprintf (stderr, "[%s] # of input files: "
 164            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s, lto_stats.num_input_files);
 165
 166   fprintf (stderr, "[%s] # of input cgraph nodes: "
 167            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 168            lto_stats.num_input_cgraph_nodes);
 169
 170   fprintf (stderr, "[%s] # of function bodies: "
 171            HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 172            lto_stats.num_function_bodies);
 173
 174   for (i = 0; i < NUM_TREE_CODES; i++)
 175     if (lto_stats.num_trees[i])
 176       fprintf (stderr, "[%s] # of '%s' objects read: "
 177                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 178                get_tree_code_name ((enum tree_code) i), lto_stats.num_trees[i]);
 179
 180   if (flag_lto)
 181     {
 182       fprintf (stderr, "[%s] Compression: "
 183                HOST_WIDE_INT_PRINT_UNSIGNED " output bytes, "
 184                HOST_WIDE_INT_PRINT_UNSIGNED " compressed bytes", s,
 185                lto_stats.num_output_il_bytes,
 186                lto_stats.num_compressed_il_bytes);
 187       if (lto_stats.num_output_il_bytes > 0)
 188         {
 189           const float dividend = (float) lto_stats.num_compressed_il_bytes;
 190           const float divisor = (float) lto_stats.num_output_il_bytes;
 191           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 192         }
 193       fprintf (stderr, "\n");
 194     }
 195
 196   if (flag_wpa)
 197     {
 198       fprintf (stderr, "[%s] # of output files: "
 199                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 200                lto_stats.num_output_files);
 201
 202       fprintf (stderr, "[%s] # of output symtab nodes: "
 203                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 204                lto_stats.num_output_symtab_nodes);
 205
 206       fprintf (stderr, "[%s] # of output tree pickle references: "
 207                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 208                lto_stats.num_pickle_refs_output);
 209       fprintf (stderr, "[%s] # of output tree bodies: "
 210                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 211                lto_stats.num_tree_bodies_output);
 212
 213       fprintf (stderr, "[%s] # callgraph partitions: "
 214                HOST_WIDE_INT_PRINT_UNSIGNED "\n", s,
 215                lto_stats.num_cgraph_partitions);
 216
 217       fprintf (stderr, "[%s] Compression: "
 218                HOST_WIDE_INT_PRINT_UNSIGNED " input bytes, "
 219                HOST_WIDE_INT_PRINT_UNSIGNED " uncompressed bytes", s,
 220                lto_stats.num_input_il_bytes,
 221                lto_stats.num_uncompressed_il_bytes);
 222       if (lto_stats.num_input_il_bytes > 0)
 223         {
 224           const float dividend = (float) lto_stats.num_uncompressed_il_bytes;
 225           const float divisor = (float) lto_stats.num_input_il_bytes;
 226           fprintf (stderr, " (ratio: %f)", dividend / divisor);
 227         }
 228       fprintf (stderr, "\n");
 229     }
 230
 231   for (i = 0; i < LTO_N_SECTION_TYPES; i++)
 232     fprintf (stderr, "[%s] Size of mmap'd section %s: "
 233              HOST_WIDE_INT_PRINT_UNSIGNED " bytes\n", s,
 234              lto_section_name[i], lto_stats.section_size[i]);
 235 }
 236
 237 /* Initialization common to the LTO reader and writer.  */
 238
 239 void
 240 lto_streamer_init (void)
 241 {
 242   /* Check that all the TS_* handled by the reader and writer routines
 243      match exactly the structures defined in treestruct.def.  When a
 244      new TS_* astructure is added, the streamer should be updated to
 245      handle it.  */
 246   if (flag_checking)
 247     streamer_check_handled_ts_structures ();
 248 }
 249
 250
 251 /* Gate function for all LTO streaming passes.  */
 252
 253 bool
 254 gate_lto_out (void)
 255 {
 256   return ((flag_generate_lto || flag_generate_offload || in_lto_p)
 257           /* Don't bother doing anything if the program has errors.  */
 258           && !seen_error ());
 259 }
 260
 261 /* Check that the version MAJOR.MINOR is the correct version number.  */
 262
 263 void
 264 lto_check_version (int major, int minor, const char *file_name)
 265 {
 266   if (major != LTO_major_version || minor != LTO_minor_version)
 267     fatal_error (input_location,
 268                  "bytecode stream in file %qs generated with LTO version "
 269                  "%d.%d instead of the expected %d.%d",
 270                  file_name,
 271                  major, minor,
 272                  LTO_major_version, LTO_minor_version);
 273 }
 274
 275
 276 /* Initialize all the streamer hooks used for streaming GIMPLE.  */
 277
 278 void
 279 lto_streamer_hooks_init (void)
 280 {
 281   streamer_hooks_init ();
 282   streamer_hooks.write_tree = lto_output_tree;
 283   streamer_hooks.read_tree = lto_input_tree;
 284   streamer_hooks.input_location = lto_input_location;
 285   streamer_hooks.output_location = lto_output_location;
 286   streamer_hooks.output_location_and_block = lto_output_location_and_block;
 287 }