gcc/gimple-streamer-in.c

   1 /* Routines for reading GIMPLE from a file stream.
   2
   3    Copyright 2011 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 = VEC_index (tree, SSANAMES (fn), ix);
  46   len = EDGE_COUNT (bb->preds);
  47   result = create_phi_node (phi_result, bb);
  48   SSA_NAME_DEF_STMT (phi_result) = result;
  49
  50   /* We have to go through a lookup process here because the preds in the
  51      reconstructed graph are generally in a different order than they
  52      were in the original program.  */
  53   for (i = 0; i < len; i++)
  54     {
  55       tree def = stream_read_tree (ib, data_in);
  56       int src_index = streamer_read_uhwi (ib);
  57       location_t arg_loc = lto_input_location (ib, 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, lto_input_location (ib, 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 op = stream_read_tree (ib, data_in);
 147           gimple_set_op (stmt, i, op);
 148           if (!op)
 149             continue;
 150
 151           /* Fixup FIELD_DECLs in COMPONENT_REFs, they are not handled
 152              by decl merging.  */
 153           if (TREE_CODE (op) == ADDR_EXPR)
 154             op = TREE_OPERAND (op, 0);
 155           while (handled_component_p (op))
 156             {
 157               if (TREE_CODE (op) == COMPONENT_REF)
 158                 {
 159                   tree field, type, tem;
 160                   tree closest_match = NULL_TREE;
 161                   field = TREE_OPERAND (op, 1);
 162                   type = DECL_CONTEXT (field);
 163                   for (tem = TYPE_FIELDS (type); tem; tem = TREE_CHAIN (tem))
 164                     {
 165                       if (tem == field)
 166                         break;
 167                       if (DECL_NONADDRESSABLE_P (tem)
 168                           == DECL_NONADDRESSABLE_P (field)
 169                           && gimple_compare_field_offset (tem, field))
 170                         {
 171                           if (types_compatible_p (TREE_TYPE (tem),
 172                                                   TREE_TYPE (field)))
 173                             break;
 174                           else
 175                             closest_match = tem;
 176                         }
 177                     }
 178                   /* In case of type mismatches across units we can fail
 179                      to unify some types and thus not find a proper
 180                      field-decl here.  */
 181                   if (tem == NULL_TREE)
 182                     {
 183                       /* Thus, emit a ODR violation warning.  */
 184                       if (warning_at (gimple_location (stmt), 0,
 185                                       "use of type %<%E%> with two mismatching "
 186                                       "declarations at field %<%E%>",
 187                                       type, TREE_OPERAND (op, 1)))
 188                         {
 189                           if (TYPE_FIELDS (type))
 190                             inform (DECL_SOURCE_LOCATION (TYPE_FIELDS (type)),
 191                                     "original type declared here");
 192                           inform (DECL_SOURCE_LOCATION (TREE_OPERAND (op, 1)),
 193                                   "field in mismatching type declared here");
 194                           if (TYPE_NAME (TREE_TYPE (field))
 195                               && (TREE_CODE (TYPE_NAME (TREE_TYPE (field)))
 196                                   == TYPE_DECL))
 197                             inform (DECL_SOURCE_LOCATION
 198                                       (TYPE_NAME (TREE_TYPE (field))),
 199                                     "type of field declared here");
 200                           if (closest_match
 201                               && TYPE_NAME (TREE_TYPE (closest_match))
 202                               && (TREE_CODE (TYPE_NAME
 203                                    (TREE_TYPE (closest_match))) == TYPE_DECL))
 204                             inform (DECL_SOURCE_LOCATION
 205                                       (TYPE_NAME (TREE_TYPE (closest_match))),
 206                                     "type of mismatching field declared here");
 207                         }
 208                       /* And finally fixup the types.  */
 209                       TREE_OPERAND (op, 0)
 210                         = build1 (VIEW_CONVERT_EXPR, type,
 211                                   TREE_OPERAND (op, 0));
 212                     }
 213                   else
 214                     TREE_OPERAND (op, 1) = tem;
 215                 }
 216
 217               op = TREE_OPERAND (op, 0);
 218             }
 219         }
 220       if (is_gimple_call (stmt))
 221         {
 222           if (gimple_call_internal_p (stmt))
 223             gimple_call_set_internal_fn
 224               (stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 225           else
 226             gimple_call_set_fntype (stmt, stream_read_tree (ib, data_in));
 227         }
 228       break;
 229
 230     case GIMPLE_NOP:
 231     case GIMPLE_PREDICT:
 232       break;
 233
 234     default:
 235       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 236                       lto_tag_name (tag));
 237     }
 238
 239   /* Update the properties of symbols, SSA names and labels associated
 240      with STMT.  */
 241   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 242     {
 243       tree lhs = gimple_get_lhs (stmt);
 244       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 245         SSA_NAME_DEF_STMT (lhs) = stmt;
 246     }
 247   else if (code == GIMPLE_LABEL)
 248     gcc_assert (emit_label_in_global_context_p (gimple_label_label (stmt))
 249                 || DECL_CONTEXT (gimple_label_label (stmt)) == fn->decl);
 250   else if (code == GIMPLE_ASM)
 251     {
 252       unsigned i;
 253
 254       for (i = 0; i < gimple_asm_noutputs (stmt); i++)
 255         {
 256           tree op = TREE_VALUE (gimple_asm_output_op (stmt, i));
 257           if (TREE_CODE (op) == SSA_NAME)
 258             SSA_NAME_DEF_STMT (op) = stmt;
 259         }
 260     }
 261
 262   /* Reset alias information.  */
 263   if (code == GIMPLE_CALL)
 264     gimple_call_reset_alias_info (stmt);
 265
 266   /* Mark the statement modified so its operand vectors can be filled in.  */
 267   gimple_set_modified (stmt, true);
 268
 269   return stmt;
 270 }
 271
 272
 273 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 274    FN is the function being processed.  */
 275
 276 void
 277 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 278           struct data_in *data_in, struct function *fn,
 279           int count_materialization_scale)
 280 {
 281   unsigned int index;
 282   basic_block bb;
 283   gimple_stmt_iterator bsi;
 284
 285   /* This routine assumes that CFUN is set to FN, as it needs to call
 286      basic GIMPLE routines that use CFUN.  */
 287   gcc_assert (cfun == fn);
 288
 289   index = streamer_read_uhwi (ib);
 290   bb = BASIC_BLOCK_FOR_FUNCTION (fn, index);
 291
 292   bb->count = (streamer_read_hwi (ib) * count_materialization_scale
 293                + REG_BR_PROB_BASE / 2) / REG_BR_PROB_BASE;
 294   bb->loop_depth = streamer_read_hwi (ib);
 295   bb->frequency = streamer_read_hwi (ib);
 296   bb->flags = streamer_read_hwi (ib);
 297
 298   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 299   if (tag == LTO_bb0)
 300     return;
 301
 302   bsi = gsi_start_bb (bb);
 303   tag = streamer_read_record_start (ib);
 304   while (tag)
 305     {
 306       gimple stmt = input_gimple_stmt (ib, data_in, fn, tag);
 307       if (!is_gimple_debug (stmt))
 308         find_referenced_vars_in (stmt);
 309       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 310
 311       /* After the statement, expect a 0 delimiter or the EH region
 312          that the previous statement belongs to.  */
 313       tag = streamer_read_record_start (ib);
 314       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 315
 316       if (tag == LTO_eh_region)
 317         {
 318           HOST_WIDE_INT region = streamer_read_hwi (ib);
 319           gcc_assert (region == (int) region);
 320           add_stmt_to_eh_lp (stmt, region);
 321         }
 322
 323       tag = streamer_read_record_start (ib);
 324     }
 325
 326   tag = streamer_read_record_start (ib);
 327   while (tag)
 328     {
 329       gimple phi = input_phi (ib, bb, data_in, fn);
 330       find_referenced_vars_in (phi);
 331       tag = streamer_read_record_start (ib);
 332     }
 333 }