gcc/gimple-streamer-in.c

   1 /* Routines for reading GIMPLE from a file stream.
   2
   3    Copyright (C) 2011-2013 Free Software Foundation, Inc.
   4    Contributed by Diego Novillo <dnovillo@google.com>
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16 for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "diagnostic.h"
  26 #include "tree.h"
  27 #include "gimple.h"
  28 #include "gimple-ssa.h"
  29 #include "tree-phinodes.h"
  30 #include "tree-ssanames.h"
  31 #include "data-streamer.h"
  32 #include "tree-streamer.h"
  33 #include "gimple-streamer.h"
  34 #include "value-prof.h"
  35
  36 /* Read a PHI function for basic block BB in function FN.  DATA_IN is
  37    the file being read.  IB is the input block to use for reading.  */
  38
  39 static gimple
  40 input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
  41            struct function *fn)
  42 {
  43   unsigned HOST_WIDE_INT ix;
  44   tree phi_result;
  45   int i, len;
  46   gimple result;
  47
  48   ix = streamer_read_uhwi (ib);
  49   phi_result = (*SSANAMES (fn))[ix];
  50   len = EDGE_COUNT (bb->preds);
  51   result = create_phi_node (phi_result, bb);
  52
  53   /* We have to go through a lookup process here because the preds in the
  54      reconstructed graph are generally in a different order than they
  55      were in the original program.  */
  56   for (i = 0; i < len; i++)
  57     {
  58       tree def = stream_read_tree (ib, data_in);
  59       int src_index = streamer_read_uhwi (ib);
  60       bitpack_d bp = streamer_read_bitpack (ib);
  61       location_t arg_loc = stream_input_location (&bp, data_in);
  62       basic_block sbb = BASIC_BLOCK_FOR_FUNCTION (fn, src_index);
  63
  64       edge e = NULL;
  65       int j;
  66
  67       for (j = 0; j < len; j++)
  68         if (EDGE_PRED (bb, j)->src == sbb)
  69           {
  70             e = EDGE_PRED (bb, j);
  71             break;
  72           }
  73
  74       add_phi_arg (result, def, e, arg_loc);
  75     }
  76
  77   return result;
  78 }
  79
  80
  81 /* Read a statement with tag TAG in function FN from block IB using
  82    descriptors in DATA_IN.  */
  83
  84 static gimple
  85 input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
  86                    enum LTO_tags tag)
  87 {
  88   gimple stmt;
  89   enum gimple_code code;
  90   unsigned HOST_WIDE_INT num_ops;
  91   size_t i;
  92   struct bitpack_d bp;
  93   bool has_hist;
  94
  95   code = lto_tag_to_gimple_code (tag);
  96
  97   /* Read the tuple header.  */
  98   bp = streamer_read_bitpack (ib);
  99   num_ops = bp_unpack_var_len_unsigned (&bp);
 100   stmt = gimple_alloc (code, num_ops);
 101   stmt->gsbase.no_warning = bp_unpack_value (&bp, 1);
 102   if (is_gimple_assign (stmt))
 103     stmt->gsbase.nontemporal_move = bp_unpack_value (&bp, 1);
 104   stmt->gsbase.has_volatile_ops = bp_unpack_value (&bp, 1);
 105   has_hist = bp_unpack_value (&bp, 1);
 106   stmt->gsbase.subcode = bp_unpack_var_len_unsigned (&bp);
 107
 108   /* Read location information.  */
 109   gimple_set_location (stmt, stream_input_location (&bp, data_in));
 110
 111   /* Read lexical block reference.  */
 112   gimple_set_block (stmt, stream_read_tree (ib, data_in));
 113
 114   /* Read in all the operands.  */
 115   switch (code)
 116     {
 117     case GIMPLE_RESX:
 118       gimple_resx_set_region (stmt, streamer_read_hwi (ib));
 119       break;
 120
 121     case GIMPLE_EH_MUST_NOT_THROW:
 122       gimple_eh_must_not_throw_set_fndecl (stmt, stream_read_tree (ib, data_in));
 123       break;
 124
 125     case GIMPLE_EH_DISPATCH:
 126       gimple_eh_dispatch_set_region (stmt, streamer_read_hwi (ib));
 127       break;
 128
 129     case GIMPLE_ASM:
 130       {
 131         /* FIXME lto.  Move most of this into a new gimple_asm_set_string().  */
 132         tree str;
 133         stmt->gimple_asm.ni = streamer_read_uhwi (ib);
 134         stmt->gimple_asm.no = streamer_read_uhwi (ib);
 135         stmt->gimple_asm.nc = streamer_read_uhwi (ib);
 136         stmt->gimple_asm.nl = streamer_read_uhwi (ib);
 137         str = streamer_read_string_cst (data_in, ib);
 138         stmt->gimple_asm.string = TREE_STRING_POINTER (str);
 139       }
 140       /* Fallthru  */
 141
 142     case GIMPLE_ASSIGN:
 143     case GIMPLE_CALL:
 144     case GIMPLE_RETURN:
 145     case GIMPLE_SWITCH:
 146     case GIMPLE_LABEL:
 147     case GIMPLE_COND:
 148     case GIMPLE_GOTO:
 149     case GIMPLE_DEBUG:
 150       for (i = 0; i < num_ops; i++)
 151         {
 152           tree *opp, op = stream_read_tree (ib, data_in);
 153           gimple_set_op (stmt, i, op);
 154           if (!op)
 155             continue;
 156
 157           opp = gimple_op_ptr (stmt, i);
 158           if (TREE_CODE (*opp) == ADDR_EXPR)
 159             opp = &TREE_OPERAND (*opp, 0);
 160           while (handled_component_p (*opp))
 161             {
 162               if (TREE_CODE (*opp) == COMPONENT_REF)
 163                 {
 164                   /* Fixup FIELD_DECLs in COMPONENT_REFs, they are not handled
 165                      by decl merging.  */
 166                   tree field, type, tem;
 167                   tree closest_match = NULL_TREE;
 168                   field = TREE_OPERAND (*opp, 1);
 169                   type = DECL_CONTEXT (field);
 170                   for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem))
 171                     {
 172                       if (TREE_CODE (tem) != FIELD_DECL)
 173                         continue;
 174                       if (tem == field)
 175                         break;
 176                       if (DECL_NONADDRESSABLE_P (tem)
 177                           == DECL_NONADDRESSABLE_P (field)
 178                           && gimple_compare_field_offset (tem, field))
 179                         {
 180                           if (types_compatible_p (TREE_TYPE (tem),
 181                                                   TREE_TYPE (field)))
 182                             break;
 183                           else
 184                             closest_match = tem;
 185                         }
 186                     }
 187                   /* In case of type mismatches across units we can fail
 188                      to unify some types and thus not find a proper
 189                      field-decl here.  */
 190                   if (tem == NULL_TREE)
 191                     {
 192                       /* Thus, emit a ODR violation warning.  */
 193                       if (warning_at (gimple_location (stmt), 0,
 194                                       "use of type %<%E%> with two mismatching "
 195                                       "declarations at field %<%E%>",
 196                                       type, TREE_OPERAND (*opp, 1)))
 197                         {
 198                           if (TYPE_FIELDS (type))
 199                             inform (DECL_SOURCE_LOCATION (TYPE_FIELDS (type)),
 200                                     "original type declared here");
 201                           inform (DECL_SOURCE_LOCATION (TREE_OPERAND (*opp, 1)),
 202                                   "field in mismatching type declared here");
 203                           if (TYPE_NAME (TREE_TYPE (field))
 204                               && (TREE_CODE (TYPE_NAME (TREE_TYPE (field)))
 205                                   == TYPE_DECL))
 206                             inform (DECL_SOURCE_LOCATION
 207                                       (TYPE_NAME (TREE_TYPE (field))),
 208                                     "type of field declared here");
 209                           if (closest_match
 210                               && TYPE_NAME (TREE_TYPE (closest_match))
 211                               && (TREE_CODE (TYPE_NAME
 212                                    (TREE_TYPE (closest_match))) == TYPE_DECL))
 213                             inform (DECL_SOURCE_LOCATION
 214                                       (TYPE_NAME (TREE_TYPE (closest_match))),
 215                                     "type of mismatching field declared here");
 216                         }
 217                       /* And finally fixup the types.  */
 218                       TREE_OPERAND (*opp, 0)
 219                         = build1 (VIEW_CONVERT_EXPR, type,
 220                                   TREE_OPERAND (*opp, 0));
 221                     }
 222                   else
 223                     TREE_OPERAND (*opp, 1) = tem;
 224                 }
 225               else if ((TREE_CODE (*opp) == ARRAY_REF
 226                         || TREE_CODE (*opp) == ARRAY_RANGE_REF)
 227                        && (TREE_CODE (TREE_TYPE (TREE_OPERAND (*opp, 0)))
 228                            != ARRAY_TYPE))
 229                 {
 230                   /* And ARRAY_REFs to objects that had mismatched types
 231                      during symbol merging to avoid ICEs.  */
 232                   TREE_OPERAND (*opp, 0)
 233                     = build1 (VIEW_CONVERT_EXPR,
 234                               build_array_type (TREE_TYPE (*opp), NULL_TREE),
 235                               TREE_OPERAND (*opp, 0));
 236                 }
 237
 238               opp = &TREE_OPERAND (*opp, 0);
 239             }
 240           /* At LTO output time we wrap all global decls in MEM_REFs to
 241              allow seamless replacement with prevailing decls.  Undo this
 242              here if the prevailing decl allows for this.
 243              ???  Maybe we should simply fold all stmts.  */
 244           if (TREE_CODE (*opp) == MEM_REF
 245               && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
 246               && integer_zerop (TREE_OPERAND (*opp, 1))
 247               && (TREE_THIS_VOLATILE (*opp)
 248                   == TREE_THIS_VOLATILE
 249                        (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
 250               && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
 251               && (TREE_TYPE (*opp)
 252                   == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
 253               && (TREE_TYPE (*opp)
 254                   == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
 255             *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
 256         }
 257       if (is_gimple_call (stmt))
 258         {
 259           if (gimple_call_internal_p (stmt))
 260             gimple_call_set_internal_fn
 261               (stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 262           else
 263             gimple_call_set_fntype (stmt, stream_read_tree (ib, data_in));
 264         }
 265       break;
 266
 267     case GIMPLE_NOP:
 268     case GIMPLE_PREDICT:
 269       break;
 270
 271     case GIMPLE_TRANSACTION:
 272       gimple_transaction_set_label (stmt, stream_read_tree (ib, data_in));
 273       break;
 274
 275     default:
 276       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 277                       lto_tag_name (tag));
 278     }
 279
 280   /* Update the properties of symbols, SSA names and labels associated
 281      with STMT.  */
 282   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 283     {
 284       tree lhs = gimple_get_lhs (stmt);
 285       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 286         SSA_NAME_DEF_STMT (lhs) = stmt;
 287     }
 288   else if (code == GIMPLE_ASM)
 289     {
 290       unsigned i;
 291
 292       for (i = 0; i < gimple_asm_noutputs (stmt); i++)
 293         {
 294           tree op = TREE_VALUE (gimple_asm_output_op (stmt, i));
 295           if (TREE_CODE (op) == SSA_NAME)
 296             SSA_NAME_DEF_STMT (op) = stmt;
 297         }
 298     }
 299
 300   /* Reset alias information.  */
 301   if (code == GIMPLE_CALL)
 302     gimple_call_reset_alias_info (stmt);
 303
 304   /* Mark the statement modified so its operand vectors can be filled in.  */
 305   gimple_set_modified (stmt, true);
 306   if (has_hist)
 307     stream_in_histogram_value (ib, stmt);
 308
 309   return stmt;
 310 }
 311
 312
 313 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 314    FN is the function being processed.  */
 315
 316 void
 317 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 318           struct data_in *data_in, struct function *fn,
 319           int count_materialization_scale)
 320 {
 321   unsigned int index;
 322   basic_block bb;
 323   gimple_stmt_iterator bsi;
 324
 325   /* This routine assumes that CFUN is set to FN, as it needs to call
 326      basic GIMPLE routines that use CFUN.  */
 327   gcc_assert (cfun == fn);
 328
 329   index = streamer_read_uhwi (ib);
 330   bb = BASIC_BLOCK_FOR_FUNCTION (fn, index);
 331
 332   bb->count = apply_scale (streamer_read_gcov_count (ib),
 333                            count_materialization_scale);
 334   bb->frequency = streamer_read_hwi (ib);
 335   bb->flags = streamer_read_hwi (ib);
 336
 337   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 338   if (tag == LTO_bb0)
 339     return;
 340
 341   bsi = gsi_start_bb (bb);
 342   tag = streamer_read_record_start (ib);
 343   while (tag)
 344     {
 345       gimple stmt = input_gimple_stmt (ib, data_in, tag);
 346       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 347
 348       /* After the statement, expect a 0 delimiter or the EH region
 349          that the previous statement belongs to.  */
 350       tag = streamer_read_record_start (ib);
 351       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 352
 353       if (tag == LTO_eh_region)
 354         {
 355           HOST_WIDE_INT region = streamer_read_hwi (ib);
 356           gcc_assert (region == (int) region);
 357           add_stmt_to_eh_lp (stmt, region);
 358         }
 359
 360       tag = streamer_read_record_start (ib);
 361     }
 362
 363   tag = streamer_read_record_start (ib);
 364   while (tag)
 365     {
 366       input_phi (ib, bb, data_in, fn);
 367       tag = streamer_read_record_start (ib);
 368     }
 369 }