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