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 "input.h"
  27 #include "alias.h"
  28 #include "symtab.h"
  29 #include "options.h"
  30 #include "tree.h"
  31 #include "fold-const.h"
  32 #include "predict.h"
  33 #include "tm.h"
  34 #include "hard-reg-set.h"
  35 #include "input.h"
  36 #include "function.h"
  37 #include "dominance.h"
  38 #include "cfg.h"
  39 #include "basic-block.h"
  40 #include "tree-ssa-alias.h"
  41 #include "internal-fn.h"
  42 #include "tree-eh.h"
  43 #include "gimple-expr.h"
  44 #include "is-a.h"
  45 #include "gimple.h"
  46 #include "gimple-iterator.h"
  47 #include "gimple-ssa.h"
  48 #include "tree-phinodes.h"
  49 #include "stringpool.h"
  50 #include "tree-ssanames.h"
  51 #include "plugin-api.h"
  52 #include "ipa-ref.h"
  53 #include "cgraph.h"
  54 #include "data-streamer.h"
  55 #include "tree-streamer.h"
  56 #include "gimple-streamer.h"
  57 #include "value-prof.h"
  58
  59 /* Read a PHI function for basic block BB in function FN.  DATA_IN is
  60    the file being read.  IB is the input block to use for reading.  */
  61
  62 static gphi *
  63 input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
  64            struct function *fn)
  65 {
  66   unsigned HOST_WIDE_INT ix;
  67   tree phi_result;
  68   int i, len;
  69   gphi *result;
  70
  71   ix = streamer_read_uhwi (ib);
  72   phi_result = (*SSANAMES (fn))[ix];
  73   len = EDGE_COUNT (bb->preds);
  74   result = create_phi_node (phi_result, bb);
  75
  76   /* We have to go through a lookup process here because the preds in the
  77      reconstructed graph are generally in a different order than they
  78      were in the original program.  */
  79   for (i = 0; i < len; i++)
  80     {
  81       tree def = stream_read_tree (ib, data_in);
  82       int src_index = streamer_read_uhwi (ib);
  83       bitpack_d bp = streamer_read_bitpack (ib);
  84       /* Do not cache a location - we do not have API to get pointer to the
  85          location in PHI statement and we may trigger reallocation.  */
  86       location_t arg_loc = stream_input_location_now (&bp, data_in);
  87       basic_block sbb = BASIC_BLOCK_FOR_FN (fn, src_index);
  88
  89       edge e = NULL;
  90       int j;
  91
  92       for (j = 0; j < len; j++)
  93         if (EDGE_PRED (bb, j)->src == sbb)
  94           {
  95             e = EDGE_PRED (bb, j);
  96             break;
  97           }
  98
  99       add_phi_arg (result, def, e, arg_loc);
 100     }
 101
 102   return result;
 103 }
 104
 105
 106 /* Read a statement with tag TAG in function FN from block IB using
 107    descriptors in DATA_IN.  */
 108
 109 static gimple
 110 input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
 111                    enum LTO_tags tag)
 112 {
 113   gimple stmt;
 114   enum gimple_code code;
 115   unsigned HOST_WIDE_INT num_ops;
 116   size_t i;
 117   struct bitpack_d bp;
 118   bool has_hist;
 119
 120   code = lto_tag_to_gimple_code (tag);
 121
 122   /* Read the tuple header.  */
 123   bp = streamer_read_bitpack (ib);
 124   num_ops = bp_unpack_var_len_unsigned (&bp);
 125   stmt = gimple_alloc (code, num_ops);
 126   stmt->no_warning = bp_unpack_value (&bp, 1);
 127   if (is_gimple_assign (stmt))
 128     stmt->nontemporal_move = bp_unpack_value (&bp, 1);
 129   stmt->has_volatile_ops = bp_unpack_value (&bp, 1);
 130   has_hist = bp_unpack_value (&bp, 1);
 131   stmt->subcode = bp_unpack_var_len_unsigned (&bp);
 132
 133   /* Read location information.  Caching here makes no sense until streamer
 134      cache can handle the following gimple_set_block.  */
 135   gimple_set_location (stmt, stream_input_location_now (&bp, data_in));
 136
 137   /* Read lexical block reference.  */
 138   gimple_set_block (stmt, stream_read_tree (ib, data_in));
 139
 140   /* Read in all the operands.  */
 141   switch (code)
 142     {
 143     case GIMPLE_RESX:
 144       gimple_resx_set_region (as_a <gresx *> (stmt),
 145                               streamer_read_hwi (ib));
 146       break;
 147
 148     case GIMPLE_EH_MUST_NOT_THROW:
 149       gimple_eh_must_not_throw_set_fndecl (
 150         as_a <geh_mnt *> (stmt),
 151         stream_read_tree (ib, data_in));
 152       break;
 153
 154     case GIMPLE_EH_DISPATCH:
 155       gimple_eh_dispatch_set_region (as_a <geh_dispatch *> (stmt),
 156                                      streamer_read_hwi (ib));
 157       break;
 158
 159     case GIMPLE_ASM:
 160       {
 161         /* FIXME lto.  Move most of this into a new gimple_asm_set_string().  */
 162         gasm *asm_stmt = as_a <gasm *> (stmt);
 163         tree str;
 164         asm_stmt->ni = streamer_read_uhwi (ib);
 165         asm_stmt->no = streamer_read_uhwi (ib);
 166         asm_stmt->nc = streamer_read_uhwi (ib);
 167         asm_stmt->nl = streamer_read_uhwi (ib);
 168         str = streamer_read_string_cst (data_in, ib);
 169         asm_stmt->string = TREE_STRING_POINTER (str);
 170       }
 171       /* Fallthru  */
 172
 173     case GIMPLE_ASSIGN:
 174     case GIMPLE_CALL:
 175     case GIMPLE_RETURN:
 176     case GIMPLE_SWITCH:
 177     case GIMPLE_LABEL:
 178     case GIMPLE_COND:
 179     case GIMPLE_GOTO:
 180     case GIMPLE_DEBUG:
 181       for (i = 0; i < num_ops; i++)
 182         {
 183           tree *opp, op = stream_read_tree (ib, data_in);
 184           gimple_set_op (stmt, i, op);
 185           if (!op)
 186             continue;
 187
 188           opp = gimple_op_ptr (stmt, i);
 189           if (TREE_CODE (*opp) == ADDR_EXPR)
 190             opp = &TREE_OPERAND (*opp, 0);
 191           while (handled_component_p (*opp))
 192             opp = &TREE_OPERAND (*opp, 0);
 193           /* At LTO output time we wrap all global decls in MEM_REFs to
 194              allow seamless replacement with prevailing decls.  Undo this
 195              here if the prevailing decl allows for this.
 196              ???  Maybe we should simply fold all stmts.  */
 197           if (TREE_CODE (*opp) == MEM_REF
 198               && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
 199               && integer_zerop (TREE_OPERAND (*opp, 1))
 200               && (TREE_THIS_VOLATILE (*opp)
 201                   == TREE_THIS_VOLATILE
 202                        (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
 203               && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
 204               && (TREE_TYPE (*opp)
 205                   == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
 206               && (TREE_TYPE (*opp)
 207                   == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
 208             *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
 209         }
 210       if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
 211         {
 212           if (gimple_call_internal_p (call_stmt))
 213             gimple_call_set_internal_fn
 214               (call_stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 215           else
 216             gimple_call_set_fntype (call_stmt, stream_read_tree (ib, data_in));
 217         }
 218       break;
 219
 220     case GIMPLE_NOP:
 221     case GIMPLE_PREDICT:
 222       break;
 223
 224     case GIMPLE_TRANSACTION:
 225       gimple_transaction_set_label (as_a <gtransaction *> (stmt),
 226                                     stream_read_tree (ib, data_in));
 227       break;
 228
 229     default:
 230       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 231                       lto_tag_name (tag));
 232     }
 233
 234   /* Update the properties of symbols, SSA names and labels associated
 235      with STMT.  */
 236   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 237     {
 238       tree lhs = gimple_get_lhs (stmt);
 239       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 240         SSA_NAME_DEF_STMT (lhs) = stmt;
 241     }
 242   else if (code == GIMPLE_ASM)
 243     {
 244       gasm *asm_stmt = as_a <gasm *> (stmt);
 245       unsigned i;
 246
 247       for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
 248         {
 249           tree op = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
 250           if (TREE_CODE (op) == SSA_NAME)
 251             SSA_NAME_DEF_STMT (op) = stmt;
 252         }
 253     }
 254
 255   /* Reset alias information.  */
 256   if (code == GIMPLE_CALL)
 257     gimple_call_reset_alias_info (as_a <gcall *> (stmt));
 258
 259   /* Mark the statement modified so its operand vectors can be filled in.  */
 260   gimple_set_modified (stmt, true);
 261   if (has_hist)
 262     stream_in_histogram_value (ib, stmt);
 263
 264   return stmt;
 265 }
 266
 267
 268 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 269    FN is the function being processed.  */
 270
 271 void
 272 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 273           struct data_in *data_in, struct function *fn,
 274           int count_materialization_scale)
 275 {
 276   unsigned int index;
 277   basic_block bb;
 278   gimple_stmt_iterator bsi;
 279
 280   /* This routine assumes that CFUN is set to FN, as it needs to call
 281      basic GIMPLE routines that use CFUN.  */
 282   gcc_assert (cfun == fn);
 283
 284   index = streamer_read_uhwi (ib);
 285   bb = BASIC_BLOCK_FOR_FN (fn, index);
 286
 287   bb->count = apply_scale (streamer_read_gcov_count (ib),
 288                            count_materialization_scale);
 289   bb->frequency = streamer_read_hwi (ib);
 290   bb->flags = streamer_read_hwi (ib);
 291
 292   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 293   if (tag == LTO_bb0)
 294     return;
 295
 296   bsi = gsi_start_bb (bb);
 297   tag = streamer_read_record_start (ib);
 298   while (tag)
 299     {
 300       gimple stmt = input_gimple_stmt (ib, data_in, tag);
 301       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 302
 303       /* After the statement, expect a 0 delimiter or the EH region
 304          that the previous statement belongs to.  */
 305       tag = streamer_read_record_start (ib);
 306       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 307
 308       if (tag == LTO_eh_region)
 309         {
 310           HOST_WIDE_INT region = streamer_read_hwi (ib);
 311           gcc_assert (region == (int) region);
 312           add_stmt_to_eh_lp (stmt, region);
 313         }
 314
 315       tag = streamer_read_record_start (ib);
 316     }
 317
 318   tag = streamer_read_record_start (ib);
 319   while (tag)
 320     {
 321       input_phi (ib, bb, data_in, fn);
 322       tag = streamer_read_record_start (ib);
 323     }
 324 }