gcc/gimple-streamer-in.c

   1 /* Routines for reading GIMPLE from a file stream.
   2
   3    Copyright (C) 2011-2015 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 "alias.h"
  27 #include "symtab.h"
  28 #include "options.h"
  29 #include "tree.h"
  30 #include "fold-const.h"
  31 #include "predict.h"
  32 #include "tm.h"
  33 #include "hard-reg-set.h"
  34 #include "function.h"
  35 #include "dominance.h"
  36 #include "cfg.h"
  37 #include "basic-block.h"
  38 #include "tree-ssa-alias.h"
  39 #include "internal-fn.h"
  40 #include "tree-eh.h"
  41 #include "gimple-expr.h"
  42 #include "gimple.h"
  43 #include "gimple-iterator.h"
  44 #include "gimple-ssa.h"
  45 #include "tree-phinodes.h"
  46 #include "stringpool.h"
  47 #include "tree-ssanames.h"
  48 #include "plugin-api.h"
  49 #include "ipa-ref.h"
  50 #include "cgraph.h"
  51 #include "data-streamer.h"
  52 #include "tree-streamer.h"
  53 #include "gimple-streamer.h"
  54 #include "value-prof.h"
  55
  56 /* Read a PHI function for basic block BB in function FN.  DATA_IN is
  57    the file being read.  IB is the input block to use for reading.  */
  58
  59 static gphi *
  60 input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
  61            struct function *fn)
  62 {
  63   unsigned HOST_WIDE_INT ix;
  64   tree phi_result;
  65   int i, len;
  66   gphi *result;
  67
  68   ix = streamer_read_uhwi (ib);
  69   phi_result = (*SSANAMES (fn))[ix];
  70   len = EDGE_COUNT (bb->preds);
  71   result = create_phi_node (phi_result, bb);
  72
  73   /* We have to go through a lookup process here because the preds in the
  74      reconstructed graph are generally in a different order than they
  75      were in the original program.  */
  76   for (i = 0; i < len; i++)
  77     {
  78       tree def = stream_read_tree (ib, data_in);
  79       int src_index = streamer_read_uhwi (ib);
  80       bitpack_d bp = streamer_read_bitpack (ib);
  81       /* Do not cache a location - we do not have API to get pointer to the
  82          location in PHI statement and we may trigger reallocation.  */
  83       location_t arg_loc = stream_input_location_now (&bp, data_in);
  84       basic_block sbb = BASIC_BLOCK_FOR_FN (fn, src_index);
  85
  86       edge e = NULL;
  87       int j;
  88
  89       for (j = 0; j < len; j++)
  90         if (EDGE_PRED (bb, j)->src == sbb)
  91           {
  92             e = EDGE_PRED (bb, j);
  93             break;
  94           }
  95
  96       add_phi_arg (result, def, e, arg_loc);
  97     }
  98
  99   return result;
 100 }
 101
 102
 103 /* Read a statement with tag TAG in function FN from block IB using
 104    descriptors in DATA_IN.  */
 105
 106 static gimple
 107 input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
 108                    enum LTO_tags tag)
 109 {
 110   gimple stmt;
 111   enum gimple_code code;
 112   unsigned HOST_WIDE_INT num_ops;
 113   size_t i;
 114   struct bitpack_d bp;
 115   bool has_hist;
 116
 117   code = lto_tag_to_gimple_code (tag);
 118
 119   /* Read the tuple header.  */
 120   bp = streamer_read_bitpack (ib);
 121   num_ops = bp_unpack_var_len_unsigned (&bp);
 122   stmt = gimple_alloc (code, num_ops);
 123   stmt->no_warning = bp_unpack_value (&bp, 1);
 124   if (is_gimple_assign (stmt))
 125     stmt->nontemporal_move = bp_unpack_value (&bp, 1);
 126   stmt->has_volatile_ops = bp_unpack_value (&bp, 1);
 127   has_hist = bp_unpack_value (&bp, 1);
 128   stmt->subcode = bp_unpack_var_len_unsigned (&bp);
 129
 130   /* Read location information.  Caching here makes no sense until streamer
 131      cache can handle the following gimple_set_block.  */
 132   gimple_set_location (stmt, stream_input_location_now (&bp, data_in));
 133
 134   /* Read lexical block reference.  */
 135   gimple_set_block (stmt, stream_read_tree (ib, data_in));
 136
 137   /* Read in all the operands.  */
 138   switch (code)
 139     {
 140     case GIMPLE_RESX:
 141       gimple_resx_set_region (as_a <gresx *> (stmt),
 142                               streamer_read_hwi (ib));
 143       break;
 144
 145     case GIMPLE_EH_MUST_NOT_THROW:
 146       gimple_eh_must_not_throw_set_fndecl (
 147         as_a <geh_mnt *> (stmt),
 148         stream_read_tree (ib, data_in));
 149       break;
 150
 151     case GIMPLE_EH_DISPATCH:
 152       gimple_eh_dispatch_set_region (as_a <geh_dispatch *> (stmt),
 153                                      streamer_read_hwi (ib));
 154       break;
 155
 156     case GIMPLE_ASM:
 157       {
 158         /* FIXME lto.  Move most of this into a new gimple_asm_set_string().  */
 159         gasm *asm_stmt = as_a <gasm *> (stmt);
 160         tree str;
 161         asm_stmt->ni = streamer_read_uhwi (ib);
 162         asm_stmt->no = streamer_read_uhwi (ib);
 163         asm_stmt->nc = streamer_read_uhwi (ib);
 164         asm_stmt->nl = streamer_read_uhwi (ib);
 165         str = streamer_read_string_cst (data_in, ib);
 166         asm_stmt->string = TREE_STRING_POINTER (str);
 167       }
 168       /* Fallthru  */
 169
 170     case GIMPLE_ASSIGN:
 171     case GIMPLE_CALL:
 172     case GIMPLE_RETURN:
 173     case GIMPLE_SWITCH:
 174     case GIMPLE_LABEL:
 175     case GIMPLE_COND:
 176     case GIMPLE_GOTO:
 177     case GIMPLE_DEBUG:
 178       for (i = 0; i < num_ops; i++)
 179         {
 180           tree *opp, op = stream_read_tree (ib, data_in);
 181           gimple_set_op (stmt, i, op);
 182           if (!op)
 183             continue;
 184
 185           opp = gimple_op_ptr (stmt, i);
 186           if (TREE_CODE (*opp) == ADDR_EXPR)
 187             opp = &TREE_OPERAND (*opp, 0);
 188           while (handled_component_p (*opp))
 189             opp = &TREE_OPERAND (*opp, 0);
 190           /* At LTO output time we wrap all global decls in MEM_REFs to
 191              allow seamless replacement with prevailing decls.  Undo this
 192              here if the prevailing decl allows for this.
 193              ???  Maybe we should simply fold all stmts.  */
 194           if (TREE_CODE (*opp) == MEM_REF
 195               && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
 196               && integer_zerop (TREE_OPERAND (*opp, 1))
 197               && (TREE_THIS_VOLATILE (*opp)
 198                   == TREE_THIS_VOLATILE
 199                        (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
 200               && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
 201               && (TREE_TYPE (*opp)
 202                   == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
 203               && (TREE_TYPE (*opp)
 204                   == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
 205             *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
 206         }
 207       if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
 208         {
 209           if (gimple_call_internal_p (call_stmt))
 210             gimple_call_set_internal_fn
 211               (call_stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 212           else
 213             gimple_call_set_fntype (call_stmt, stream_read_tree (ib, data_in));
 214         }
 215       break;
 216
 217     case GIMPLE_NOP:
 218     case GIMPLE_PREDICT:
 219       break;
 220
 221     case GIMPLE_TRANSACTION:
 222       gimple_transaction_set_label (as_a <gtransaction *> (stmt),
 223                                     stream_read_tree (ib, data_in));
 224       break;
 225
 226     default:
 227       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 228                       lto_tag_name (tag));
 229     }
 230
 231   /* Update the properties of symbols, SSA names and labels associated
 232      with STMT.  */
 233   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 234     {
 235       tree lhs = gimple_get_lhs (stmt);
 236       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 237         SSA_NAME_DEF_STMT (lhs) = stmt;
 238     }
 239   else if (code == GIMPLE_ASM)
 240     {
 241       gasm *asm_stmt = as_a <gasm *> (stmt);
 242       unsigned i;
 243
 244       for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
 245         {
 246           tree op = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
 247           if (TREE_CODE (op) == SSA_NAME)
 248             SSA_NAME_DEF_STMT (op) = stmt;
 249         }
 250     }
 251
 252   /* Reset alias information.  */
 253   if (code == GIMPLE_CALL)
 254     gimple_call_reset_alias_info (as_a <gcall *> (stmt));
 255
 256   /* Mark the statement modified so its operand vectors can be filled in.  */
 257   gimple_set_modified (stmt, true);
 258   if (has_hist)
 259     stream_in_histogram_value (ib, stmt);
 260
 261   return stmt;
 262 }
 263
 264
 265 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 266    FN is the function being processed.  */
 267
 268 void
 269 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 270           struct data_in *data_in, struct function *fn,
 271           int count_materialization_scale)
 272 {
 273   unsigned int index;
 274   basic_block bb;
 275   gimple_stmt_iterator bsi;
 276
 277   /* This routine assumes that CFUN is set to FN, as it needs to call
 278      basic GIMPLE routines that use CFUN.  */
 279   gcc_assert (cfun == fn);
 280
 281   index = streamer_read_uhwi (ib);
 282   bb = BASIC_BLOCK_FOR_FN (fn, index);
 283
 284   bb->count = apply_scale (streamer_read_gcov_count (ib),
 285                            count_materialization_scale);
 286   bb->frequency = streamer_read_hwi (ib);
 287   bb->flags = streamer_read_hwi (ib);
 288
 289   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 290   if (tag == LTO_bb0)
 291     return;
 292
 293   bsi = gsi_start_bb (bb);
 294   tag = streamer_read_record_start (ib);
 295   while (tag)
 296     {
 297       gimple stmt = input_gimple_stmt (ib, data_in, tag);
 298       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 299
 300       /* After the statement, expect a 0 delimiter or the EH region
 301          that the previous statement belongs to.  */
 302       tag = streamer_read_record_start (ib);
 303       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 304
 305       if (tag == LTO_eh_region)
 306         {
 307           HOST_WIDE_INT region = streamer_read_hwi (ib);
 308           gcc_assert (region == (int) region);
 309           add_stmt_to_eh_lp (stmt, region);
 310         }
 311
 312       tag = streamer_read_record_start (ib);
 313     }
 314
 315   tag = streamer_read_record_start (ib);
 316   while (tag)
 317     {
 318       input_phi (ib, bb, data_in, fn);
 319       tag = streamer_read_record_start (ib);
 320     }
 321 }