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 "hash-set.h"
  27 #include "vec.h"
  28 #include "input.h"
  29 #include "alias.h"
  30 #include "symtab.h"
  31 #include "options.h"
  32 #include "inchash.h"
  33 #include "tree.h"
  34 #include "fold-const.h"
  35 #include "predict.h"
  36 #include "tm.h"
  37 #include "hard-reg-set.h"
  38 #include "input.h"
  39 #include "function.h"
  40 #include "dominance.h"
  41 #include "cfg.h"
  42 #include "basic-block.h"
  43 #include "tree-ssa-alias.h"
  44 #include "internal-fn.h"
  45 #include "tree-eh.h"
  46 #include "gimple-expr.h"
  47 #include "is-a.h"
  48 #include "gimple.h"
  49 #include "gimple-iterator.h"
  50 #include "gimple-ssa.h"
  51 #include "tree-phinodes.h"
  52 #include "stringpool.h"
  53 #include "tree-ssanames.h"
  54 #include "plugin-api.h"
  55 #include "ipa-ref.h"
  56 #include "cgraph.h"
  57 #include "data-streamer.h"
  58 #include "tree-streamer.h"
  59 #include "gimple-streamer.h"
  60 #include "value-prof.h"
  61
  62 /* Read a PHI function for basic block BB in function FN.  DATA_IN is
  63    the file being read.  IB is the input block to use for reading.  */
  64
  65 static gphi *
  66 input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
  67            struct function *fn)
  68 {
  69   unsigned HOST_WIDE_INT ix;
  70   tree phi_result;
  71   int i, len;
  72   gphi *result;
  73
  74   ix = streamer_read_uhwi (ib);
  75   phi_result = (*SSANAMES (fn))[ix];
  76   len = EDGE_COUNT (bb->preds);
  77   result = create_phi_node (phi_result, bb);
  78
  79   /* We have to go through a lookup process here because the preds in the
  80      reconstructed graph are generally in a different order than they
  81      were in the original program.  */
  82   for (i = 0; i < len; i++)
  83     {
  84       tree def = stream_read_tree (ib, data_in);
  85       int src_index = streamer_read_uhwi (ib);
  86       bitpack_d bp = streamer_read_bitpack (ib);
  87       /* Do not cache a location - we do not have API to get pointer to the
  88          location in PHI statement and we may trigger reallocation.  */
  89       location_t arg_loc = stream_input_location_now (&bp, data_in);
  90       basic_block sbb = BASIC_BLOCK_FOR_FN (fn, src_index);
  91
  92       edge e = NULL;
  93       int j;
  94
  95       for (j = 0; j < len; j++)
  96         if (EDGE_PRED (bb, j)->src == sbb)
  97           {
  98             e = EDGE_PRED (bb, j);
  99             break;
 100           }
 101
 102       add_phi_arg (result, def, e, arg_loc);
 103     }
 104
 105   return result;
 106 }
 107
 108
 109 /* Read a statement with tag TAG in function FN from block IB using
 110    descriptors in DATA_IN.  */
 111
 112 static gimple
 113 input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
 114                    enum LTO_tags tag)
 115 {
 116   gimple stmt;
 117   enum gimple_code code;
 118   unsigned HOST_WIDE_INT num_ops;
 119   size_t i;
 120   struct bitpack_d bp;
 121   bool has_hist;
 122
 123   code = lto_tag_to_gimple_code (tag);
 124
 125   /* Read the tuple header.  */
 126   bp = streamer_read_bitpack (ib);
 127   num_ops = bp_unpack_var_len_unsigned (&bp);
 128   stmt = gimple_alloc (code, num_ops);
 129   stmt->no_warning = bp_unpack_value (&bp, 1);
 130   if (is_gimple_assign (stmt))
 131     stmt->nontemporal_move = bp_unpack_value (&bp, 1);
 132   stmt->has_volatile_ops = bp_unpack_value (&bp, 1);
 133   has_hist = bp_unpack_value (&bp, 1);
 134   stmt->subcode = bp_unpack_var_len_unsigned (&bp);
 135
 136   /* Read location information.  Caching here makes no sense until streamer
 137      cache can handle the following gimple_set_block.  */
 138   gimple_set_location (stmt, stream_input_location_now (&bp, data_in));
 139
 140   /* Read lexical block reference.  */
 141   gimple_set_block (stmt, stream_read_tree (ib, data_in));
 142
 143   /* Read in all the operands.  */
 144   switch (code)
 145     {
 146     case GIMPLE_RESX:
 147       gimple_resx_set_region (as_a <gresx *> (stmt),
 148                               streamer_read_hwi (ib));
 149       break;
 150
 151     case GIMPLE_EH_MUST_NOT_THROW:
 152       gimple_eh_must_not_throw_set_fndecl (
 153         as_a <geh_mnt *> (stmt),
 154         stream_read_tree (ib, data_in));
 155       break;
 156
 157     case GIMPLE_EH_DISPATCH:
 158       gimple_eh_dispatch_set_region (as_a <geh_dispatch *> (stmt),
 159                                      streamer_read_hwi (ib));
 160       break;
 161
 162     case GIMPLE_ASM:
 163       {
 164         /* FIXME lto.  Move most of this into a new gimple_asm_set_string().  */
 165         gasm *asm_stmt = as_a <gasm *> (stmt);
 166         tree str;
 167         asm_stmt->ni = streamer_read_uhwi (ib);
 168         asm_stmt->no = streamer_read_uhwi (ib);
 169         asm_stmt->nc = streamer_read_uhwi (ib);
 170         asm_stmt->nl = streamer_read_uhwi (ib);
 171         str = streamer_read_string_cst (data_in, ib);
 172         asm_stmt->string = TREE_STRING_POINTER (str);
 173       }
 174       /* Fallthru  */
 175
 176     case GIMPLE_ASSIGN:
 177     case GIMPLE_CALL:
 178     case GIMPLE_RETURN:
 179     case GIMPLE_SWITCH:
 180     case GIMPLE_LABEL:
 181     case GIMPLE_COND:
 182     case GIMPLE_GOTO:
 183     case GIMPLE_DEBUG:
 184       for (i = 0; i < num_ops; i++)
 185         {
 186           tree *opp, op = stream_read_tree (ib, data_in);
 187           gimple_set_op (stmt, i, op);
 188           if (!op)
 189             continue;
 190
 191           opp = gimple_op_ptr (stmt, i);
 192           if (TREE_CODE (*opp) == ADDR_EXPR)
 193             opp = &TREE_OPERAND (*opp, 0);
 194           while (handled_component_p (*opp))
 195             opp = &TREE_OPERAND (*opp, 0);
 196           /* At LTO output time we wrap all global decls in MEM_REFs to
 197              allow seamless replacement with prevailing decls.  Undo this
 198              here if the prevailing decl allows for this.
 199              ???  Maybe we should simply fold all stmts.  */
 200           if (TREE_CODE (*opp) == MEM_REF
 201               && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
 202               && integer_zerop (TREE_OPERAND (*opp, 1))
 203               && (TREE_THIS_VOLATILE (*opp)
 204                   == TREE_THIS_VOLATILE
 205                        (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
 206               && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
 207               && (TREE_TYPE (*opp)
 208                   == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
 209               && (TREE_TYPE (*opp)
 210                   == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
 211             *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
 212         }
 213       if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
 214         {
 215           if (gimple_call_internal_p (call_stmt))
 216             gimple_call_set_internal_fn
 217               (call_stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 218           else
 219             gimple_call_set_fntype (call_stmt, stream_read_tree (ib, data_in));
 220         }
 221       break;
 222
 223     case GIMPLE_NOP:
 224     case GIMPLE_PREDICT:
 225       break;
 226
 227     case GIMPLE_TRANSACTION:
 228       gimple_transaction_set_label (as_a <gtransaction *> (stmt),
 229                                     stream_read_tree (ib, data_in));
 230       break;
 231
 232     default:
 233       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 234                       lto_tag_name (tag));
 235     }
 236
 237   /* Update the properties of symbols, SSA names and labels associated
 238      with STMT.  */
 239   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 240     {
 241       tree lhs = gimple_get_lhs (stmt);
 242       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 243         SSA_NAME_DEF_STMT (lhs) = stmt;
 244     }
 245   else if (code == GIMPLE_ASM)
 246     {
 247       gasm *asm_stmt = as_a <gasm *> (stmt);
 248       unsigned i;
 249
 250       for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
 251         {
 252           tree op = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
 253           if (TREE_CODE (op) == SSA_NAME)
 254             SSA_NAME_DEF_STMT (op) = stmt;
 255         }
 256     }
 257
 258   /* Reset alias information.  */
 259   if (code == GIMPLE_CALL)
 260     gimple_call_reset_alias_info (as_a <gcall *> (stmt));
 261
 262   /* Mark the statement modified so its operand vectors can be filled in.  */
 263   gimple_set_modified (stmt, true);
 264   if (has_hist)
 265     stream_in_histogram_value (ib, stmt);
 266
 267   return stmt;
 268 }
 269
 270
 271 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 272    FN is the function being processed.  */
 273
 274 void
 275 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 276           struct data_in *data_in, struct function *fn,
 277           int count_materialization_scale)
 278 {
 279   unsigned int index;
 280   basic_block bb;
 281   gimple_stmt_iterator bsi;
 282
 283   /* This routine assumes that CFUN is set to FN, as it needs to call
 284      basic GIMPLE routines that use CFUN.  */
 285   gcc_assert (cfun == fn);
 286
 287   index = streamer_read_uhwi (ib);
 288   bb = BASIC_BLOCK_FOR_FN (fn, index);
 289
 290   bb->count = apply_scale (streamer_read_gcov_count (ib),
 291                            count_materialization_scale);
 292   bb->frequency = streamer_read_hwi (ib);
 293   bb->flags = streamer_read_hwi (ib);
 294
 295   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 296   if (tag == LTO_bb0)
 297     return;
 298
 299   bsi = gsi_start_bb (bb);
 300   tag = streamer_read_record_start (ib);
 301   while (tag)
 302     {
 303       gimple stmt = input_gimple_stmt (ib, data_in, tag);
 304       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 305
 306       /* After the statement, expect a 0 delimiter or the EH region
 307          that the previous statement belongs to.  */
 308       tag = streamer_read_record_start (ib);
 309       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 310
 311       if (tag == LTO_eh_region)
 312         {
 313           HOST_WIDE_INT region = streamer_read_hwi (ib);
 314           gcc_assert (region == (int) region);
 315           add_stmt_to_eh_lp (stmt, region);
 316         }
 317
 318       tag = streamer_read_record_start (ib);
 319     }
 320
 321   tag = streamer_read_record_start (ib);
 322   while (tag)
 323     {
 324       input_phi (ib, bb, data_in, fn);
 325       tag = streamer_read_record_start (ib);
 326     }
 327 }