gcc/gimple-streamer-in.c

   1 /* Routines for reading GIMPLE from a file stream.
   2
   3    Copyright (C) 2011-2014 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 "predict.h"
  28 #include "vec.h"
  29 #include "hashtab.h"
  30 #include "hash-set.h"
  31 #include "machmode.h"
  32 #include "tm.h"
  33 #include "hard-reg-set.h"
  34 #include "input.h"
  35 #include "function.h"
  36 #include "dominance.h"
  37 #include "cfg.h"
  38 #include "basic-block.h"
  39 #include "tree-ssa-alias.h"
  40 #include "internal-fn.h"
  41 #include "tree-eh.h"
  42 #include "gimple-expr.h"
  43 #include "is-a.h"
  44 #include "gimple.h"
  45 #include "gimple-iterator.h"
  46 #include "gimple-ssa.h"
  47 #include "tree-phinodes.h"
  48 #include "stringpool.h"
  49 #include "tree-ssanames.h"
  50 #include "data-streamer.h"
  51 #include "tree-streamer.h"
  52 #include "gimple-streamer.h"
  53 #include "value-prof.h"
  54
  55 /* Read a PHI function for basic block BB in function FN.  DATA_IN is
  56    the file being read.  IB is the input block to use for reading.  */
  57
  58 static gimple
  59 input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
  60            struct function *fn)
  61 {
  62   unsigned HOST_WIDE_INT ix;
  63   tree phi_result;
  64   int i, len;
  65   gimple result;
  66
  67   ix = streamer_read_uhwi (ib);
  68   phi_result = (*SSANAMES (fn))[ix];
  69   len = EDGE_COUNT (bb->preds);
  70   result = create_phi_node (phi_result, bb);
  71
  72   /* We have to go through a lookup process here because the preds in the
  73      reconstructed graph are generally in a different order than they
  74      were in the original program.  */
  75   for (i = 0; i < len; i++)
  76     {
  77       tree def = stream_read_tree (ib, data_in);
  78       int src_index = streamer_read_uhwi (ib);
  79       bitpack_d bp = streamer_read_bitpack (ib);
  80       location_t arg_loc = stream_input_location (&bp, data_in);
  81       basic_block sbb = BASIC_BLOCK_FOR_FN (fn, src_index);
  82
  83       edge e = NULL;
  84       int j;
  85
  86       for (j = 0; j < len; j++)
  87         if (EDGE_PRED (bb, j)->src == sbb)
  88           {
  89             e = EDGE_PRED (bb, j);
  90             break;
  91           }
  92
  93       add_phi_arg (result, def, e, arg_loc);
  94     }
  95
  96   return result;
  97 }
  98
  99
 100 /* Read a statement with tag TAG in function FN from block IB using
 101    descriptors in DATA_IN.  */
 102
 103 static gimple
 104 input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
 105                    enum LTO_tags tag)
 106 {
 107   gimple stmt;
 108   enum gimple_code code;
 109   unsigned HOST_WIDE_INT num_ops;
 110   size_t i;
 111   struct bitpack_d bp;
 112   bool has_hist;
 113
 114   code = lto_tag_to_gimple_code (tag);
 115
 116   /* Read the tuple header.  */
 117   bp = streamer_read_bitpack (ib);
 118   num_ops = bp_unpack_var_len_unsigned (&bp);
 119   stmt = gimple_alloc (code, num_ops);
 120   stmt->no_warning = bp_unpack_value (&bp, 1);
 121   if (is_gimple_assign (stmt))
 122     stmt->nontemporal_move = bp_unpack_value (&bp, 1);
 123   stmt->has_volatile_ops = bp_unpack_value (&bp, 1);
 124   has_hist = bp_unpack_value (&bp, 1);
 125   stmt->subcode = bp_unpack_var_len_unsigned (&bp);
 126
 127   /* Read location information.  */
 128   gimple_set_location (stmt, stream_input_location (&bp, data_in));
 129
 130   /* Read lexical block reference.  */
 131   gimple_set_block (stmt, stream_read_tree (ib, data_in));
 132
 133   /* Read in all the operands.  */
 134   switch (code)
 135     {
 136     case GIMPLE_RESX:
 137       gimple_resx_set_region (stmt, streamer_read_hwi (ib));
 138       break;
 139
 140     case GIMPLE_EH_MUST_NOT_THROW:
 141       gimple_eh_must_not_throw_set_fndecl (stmt, stream_read_tree (ib, data_in));
 142       break;
 143
 144     case GIMPLE_EH_DISPATCH:
 145       gimple_eh_dispatch_set_region (stmt, streamer_read_hwi (ib));
 146       break;
 147
 148     case GIMPLE_ASM:
 149       {
 150         /* FIXME lto.  Move most of this into a new gimple_asm_set_string().  */
 151         gimple_statement_asm *asm_stmt = as_a <gimple_statement_asm *> (stmt);
 152         tree str;
 153         asm_stmt->ni = streamer_read_uhwi (ib);
 154         asm_stmt->no = streamer_read_uhwi (ib);
 155         asm_stmt->nc = streamer_read_uhwi (ib);
 156         asm_stmt->nl = streamer_read_uhwi (ib);
 157         str = streamer_read_string_cst (data_in, ib);
 158         asm_stmt->string = TREE_STRING_POINTER (str);
 159       }
 160       /* Fallthru  */
 161
 162     case GIMPLE_ASSIGN:
 163     case GIMPLE_CALL:
 164     case GIMPLE_RETURN:
 165     case GIMPLE_SWITCH:
 166     case GIMPLE_LABEL:
 167     case GIMPLE_COND:
 168     case GIMPLE_GOTO:
 169     case GIMPLE_DEBUG:
 170       for (i = 0; i < num_ops; i++)
 171         {
 172           tree *opp, op = stream_read_tree (ib, data_in);
 173           gimple_set_op (stmt, i, op);
 174           if (!op)
 175             continue;
 176
 177           opp = gimple_op_ptr (stmt, i);
 178           if (TREE_CODE (*opp) == ADDR_EXPR)
 179             opp = &TREE_OPERAND (*opp, 0);
 180           while (handled_component_p (*opp))
 181             opp = &TREE_OPERAND (*opp, 0);
 182           /* At LTO output time we wrap all global decls in MEM_REFs to
 183              allow seamless replacement with prevailing decls.  Undo this
 184              here if the prevailing decl allows for this.
 185              ???  Maybe we should simply fold all stmts.  */
 186           if (TREE_CODE (*opp) == MEM_REF
 187               && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
 188               && integer_zerop (TREE_OPERAND (*opp, 1))
 189               && (TREE_THIS_VOLATILE (*opp)
 190                   == TREE_THIS_VOLATILE
 191                        (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
 192               && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
 193               && (TREE_TYPE (*opp)
 194                   == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
 195               && (TREE_TYPE (*opp)
 196                   == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
 197             *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
 198         }
 199       if (is_gimple_call (stmt))
 200         {
 201           if (gimple_call_internal_p (stmt))
 202             gimple_call_set_internal_fn
 203               (stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 204           else
 205             gimple_call_set_fntype (stmt, stream_read_tree (ib, data_in));
 206         }
 207       break;
 208
 209     case GIMPLE_NOP:
 210     case GIMPLE_PREDICT:
 211       break;
 212
 213     case GIMPLE_TRANSACTION:
 214       gimple_transaction_set_label (stmt, stream_read_tree (ib, data_in));
 215       break;
 216
 217     default:
 218       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 219                       lto_tag_name (tag));
 220     }
 221
 222   /* Update the properties of symbols, SSA names and labels associated
 223      with STMT.  */
 224   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 225     {
 226       tree lhs = gimple_get_lhs (stmt);
 227       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 228         SSA_NAME_DEF_STMT (lhs) = stmt;
 229     }
 230   else if (code == GIMPLE_ASM)
 231     {
 232       unsigned i;
 233
 234       for (i = 0; i < gimple_asm_noutputs (stmt); i++)
 235         {
 236           tree op = TREE_VALUE (gimple_asm_output_op (stmt, i));
 237           if (TREE_CODE (op) == SSA_NAME)
 238             SSA_NAME_DEF_STMT (op) = stmt;
 239         }
 240     }
 241
 242   /* Reset alias information.  */
 243   if (code == GIMPLE_CALL)
 244     gimple_call_reset_alias_info (stmt);
 245
 246   /* Mark the statement modified so its operand vectors can be filled in.  */
 247   gimple_set_modified (stmt, true);
 248   if (has_hist)
 249     stream_in_histogram_value (ib, stmt);
 250
 251   return stmt;
 252 }
 253
 254
 255 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 256    FN is the function being processed.  */
 257
 258 void
 259 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 260           struct data_in *data_in, struct function *fn,
 261           int count_materialization_scale)
 262 {
 263   unsigned int index;
 264   basic_block bb;
 265   gimple_stmt_iterator bsi;
 266
 267   /* This routine assumes that CFUN is set to FN, as it needs to call
 268      basic GIMPLE routines that use CFUN.  */
 269   gcc_assert (cfun == fn);
 270
 271   index = streamer_read_uhwi (ib);
 272   bb = BASIC_BLOCK_FOR_FN (fn, index);
 273
 274   bb->count = apply_scale (streamer_read_gcov_count (ib),
 275                            count_materialization_scale);
 276   bb->frequency = streamer_read_hwi (ib);
 277   bb->flags = streamer_read_hwi (ib);
 278
 279   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 280   if (tag == LTO_bb0)
 281     return;
 282
 283   bsi = gsi_start_bb (bb);
 284   tag = streamer_read_record_start (ib);
 285   while (tag)
 286     {
 287       gimple stmt = input_gimple_stmt (ib, data_in, tag);
 288       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 289
 290       /* After the statement, expect a 0 delimiter or the EH region
 291          that the previous statement belongs to.  */
 292       tag = streamer_read_record_start (ib);
 293       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 294
 295       if (tag == LTO_eh_region)
 296         {
 297           HOST_WIDE_INT region = streamer_read_hwi (ib);
 298           gcc_assert (region == (int) region);
 299           add_stmt_to_eh_lp (stmt, region);
 300         }
 301
 302       tag = streamer_read_record_start (ib);
 303     }
 304
 305   tag = streamer_read_record_start (ib);
 306   while (tag)
 307     {
 308       input_phi (ib, bb, data_in, fn);
 309       tag = streamer_read_record_start (ib);
 310     }
 311 }