gcc/gimple-streamer-in.c

   1 /* Routines for reading GIMPLE from a file stream.
   2
   3    Copyright (C) 2011-2013 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 "basic-block.h"
  28 #include "tree-ssa-alias.h"
  29 #include "internal-fn.h"
  30 #include "tree-eh.h"
  31 #include "gimple-expr.h"
  32 #include "is-a.h"
  33 #include "gimple.h"
  34 #include "gimple-iterator.h"
  35 #include "gimple-ssa.h"
  36 #include "tree-phinodes.h"
  37 #include "stringpool.h"
  38 #include "tree-ssanames.h"
  39 #include "data-streamer.h"
  40 #include "tree-streamer.h"
  41 #include "gimple-streamer.h"
  42 #include "value-prof.h"
  43
  44 /* Read a PHI function for basic block BB in function FN.  DATA_IN is
  45    the file being read.  IB is the input block to use for reading.  */
  46
  47 static gimple
  48 input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
  49            struct function *fn)
  50 {
  51   unsigned HOST_WIDE_INT ix;
  52   tree phi_result;
  53   int i, len;
  54   gimple result;
  55
  56   ix = streamer_read_uhwi (ib);
  57   phi_result = (*SSANAMES (fn))[ix];
  58   len = EDGE_COUNT (bb->preds);
  59   result = create_phi_node (phi_result, bb);
  60
  61   /* We have to go through a lookup process here because the preds in the
  62      reconstructed graph are generally in a different order than they
  63      were in the original program.  */
  64   for (i = 0; i < len; i++)
  65     {
  66       tree def = stream_read_tree (ib, data_in);
  67       int src_index = streamer_read_uhwi (ib);
  68       bitpack_d bp = streamer_read_bitpack (ib);
  69       location_t arg_loc = stream_input_location (&bp, data_in);
  70       basic_block sbb = BASIC_BLOCK_FOR_FUNCTION (fn, src_index);
  71
  72       edge e = NULL;
  73       int j;
  74
  75       for (j = 0; j < len; j++)
  76         if (EDGE_PRED (bb, j)->src == sbb)
  77           {
  78             e = EDGE_PRED (bb, j);
  79             break;
  80           }
  81
  82       add_phi_arg (result, def, e, arg_loc);
  83     }
  84
  85   return result;
  86 }
  87
  88
  89 /* Read a statement with tag TAG in function FN from block IB using
  90    descriptors in DATA_IN.  */
  91
  92 static gimple
  93 input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
  94                    enum LTO_tags tag)
  95 {
  96   gimple stmt;
  97   enum gimple_code code;
  98   unsigned HOST_WIDE_INT num_ops;
  99   size_t i;
 100   struct bitpack_d bp;
 101   bool has_hist;
 102
 103   code = lto_tag_to_gimple_code (tag);
 104
 105   /* Read the tuple header.  */
 106   bp = streamer_read_bitpack (ib);
 107   num_ops = bp_unpack_var_len_unsigned (&bp);
 108   stmt = gimple_alloc (code, num_ops);
 109   stmt->no_warning = bp_unpack_value (&bp, 1);
 110   if (is_gimple_assign (stmt))
 111     stmt->nontemporal_move = bp_unpack_value (&bp, 1);
 112   stmt->has_volatile_ops = bp_unpack_value (&bp, 1);
 113   has_hist = bp_unpack_value (&bp, 1);
 114   stmt->subcode = bp_unpack_var_len_unsigned (&bp);
 115
 116   /* Read location information.  */
 117   gimple_set_location (stmt, stream_input_location (&bp, data_in));
 118
 119   /* Read lexical block reference.  */
 120   gimple_set_block (stmt, stream_read_tree (ib, data_in));
 121
 122   /* Read in all the operands.  */
 123   switch (code)
 124     {
 125     case GIMPLE_RESX:
 126       gimple_resx_set_region (stmt, streamer_read_hwi (ib));
 127       break;
 128
 129     case GIMPLE_EH_MUST_NOT_THROW:
 130       gimple_eh_must_not_throw_set_fndecl (stmt, stream_read_tree (ib, data_in));
 131       break;
 132
 133     case GIMPLE_EH_DISPATCH:
 134       gimple_eh_dispatch_set_region (stmt, streamer_read_hwi (ib));
 135       break;
 136
 137     case GIMPLE_ASM:
 138       {
 139         /* FIXME lto.  Move most of this into a new gimple_asm_set_string().  */
 140         gimple_statement_asm *asm_stmt = as_a <gimple_statement_asm> (stmt);
 141         tree str;
 142         asm_stmt->ni = streamer_read_uhwi (ib);
 143         asm_stmt->no = streamer_read_uhwi (ib);
 144         asm_stmt->nc = streamer_read_uhwi (ib);
 145         asm_stmt->nl = streamer_read_uhwi (ib);
 146         str = streamer_read_string_cst (data_in, ib);
 147         asm_stmt->string = TREE_STRING_POINTER (str);
 148       }
 149       /* Fallthru  */
 150
 151     case GIMPLE_ASSIGN:
 152     case GIMPLE_CALL:
 153     case GIMPLE_RETURN:
 154     case GIMPLE_SWITCH:
 155     case GIMPLE_LABEL:
 156     case GIMPLE_COND:
 157     case GIMPLE_GOTO:
 158     case GIMPLE_DEBUG:
 159       for (i = 0; i < num_ops; i++)
 160         {
 161           tree *opp, op = stream_read_tree (ib, data_in);
 162           gimple_set_op (stmt, i, op);
 163           if (!op)
 164             continue;
 165
 166           opp = gimple_op_ptr (stmt, i);
 167           if (TREE_CODE (*opp) == ADDR_EXPR)
 168             opp = &TREE_OPERAND (*opp, 0);
 169           while (handled_component_p (*opp))
 170             opp = &TREE_OPERAND (*opp, 0);
 171           /* At LTO output time we wrap all global decls in MEM_REFs to
 172              allow seamless replacement with prevailing decls.  Undo this
 173              here if the prevailing decl allows for this.
 174              ???  Maybe we should simply fold all stmts.  */
 175           if (TREE_CODE (*opp) == MEM_REF
 176               && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
 177               && integer_zerop (TREE_OPERAND (*opp, 1))
 178               && (TREE_THIS_VOLATILE (*opp)
 179                   == TREE_THIS_VOLATILE
 180                        (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
 181               && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
 182               && (TREE_TYPE (*opp)
 183                   == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
 184               && (TREE_TYPE (*opp)
 185                   == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
 186             *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
 187         }
 188       if (is_gimple_call (stmt))
 189         {
 190           if (gimple_call_internal_p (stmt))
 191             gimple_call_set_internal_fn
 192               (stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
 193           else
 194             gimple_call_set_fntype (stmt, stream_read_tree (ib, data_in));
 195         }
 196       break;
 197
 198     case GIMPLE_NOP:
 199     case GIMPLE_PREDICT:
 200       break;
 201
 202     case GIMPLE_TRANSACTION:
 203       gimple_transaction_set_label (stmt, stream_read_tree (ib, data_in));
 204       break;
 205
 206     default:
 207       internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
 208                       lto_tag_name (tag));
 209     }
 210
 211   /* Update the properties of symbols, SSA names and labels associated
 212      with STMT.  */
 213   if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
 214     {
 215       tree lhs = gimple_get_lhs (stmt);
 216       if (lhs && TREE_CODE (lhs) == SSA_NAME)
 217         SSA_NAME_DEF_STMT (lhs) = stmt;
 218     }
 219   else if (code == GIMPLE_ASM)
 220     {
 221       unsigned i;
 222
 223       for (i = 0; i < gimple_asm_noutputs (stmt); i++)
 224         {
 225           tree op = TREE_VALUE (gimple_asm_output_op (stmt, i));
 226           if (TREE_CODE (op) == SSA_NAME)
 227             SSA_NAME_DEF_STMT (op) = stmt;
 228         }
 229     }
 230
 231   /* Reset alias information.  */
 232   if (code == GIMPLE_CALL)
 233     gimple_call_reset_alias_info (stmt);
 234
 235   /* Mark the statement modified so its operand vectors can be filled in.  */
 236   gimple_set_modified (stmt, true);
 237   if (has_hist)
 238     stream_in_histogram_value (ib, stmt);
 239
 240   return stmt;
 241 }
 242
 243
 244 /* Read a basic block with tag TAG from DATA_IN using input block IB.
 245    FN is the function being processed.  */
 246
 247 void
 248 input_bb (struct lto_input_block *ib, enum LTO_tags tag,
 249           struct data_in *data_in, struct function *fn,
 250           int count_materialization_scale)
 251 {
 252   unsigned int index;
 253   basic_block bb;
 254   gimple_stmt_iterator bsi;
 255
 256   /* This routine assumes that CFUN is set to FN, as it needs to call
 257      basic GIMPLE routines that use CFUN.  */
 258   gcc_assert (cfun == fn);
 259
 260   index = streamer_read_uhwi (ib);
 261   bb = BASIC_BLOCK_FOR_FUNCTION (fn, index);
 262
 263   bb->count = apply_scale (streamer_read_gcov_count (ib),
 264                            count_materialization_scale);
 265   bb->frequency = streamer_read_hwi (ib);
 266   bb->flags = streamer_read_hwi (ib);
 267
 268   /* LTO_bb1 has statements.  LTO_bb0 does not.  */
 269   if (tag == LTO_bb0)
 270     return;
 271
 272   bsi = gsi_start_bb (bb);
 273   tag = streamer_read_record_start (ib);
 274   while (tag)
 275     {
 276       gimple stmt = input_gimple_stmt (ib, data_in, tag);
 277       gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
 278
 279       /* After the statement, expect a 0 delimiter or the EH region
 280          that the previous statement belongs to.  */
 281       tag = streamer_read_record_start (ib);
 282       lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
 283
 284       if (tag == LTO_eh_region)
 285         {
 286           HOST_WIDE_INT region = streamer_read_hwi (ib);
 287           gcc_assert (region == (int) region);
 288           add_stmt_to_eh_lp (stmt, region);
 289         }
 290
 291       tag = streamer_read_record_start (ib);
 292     }
 293
 294   tag = streamer_read_record_start (ib);
 295   while (tag)
 296     {
 297       input_phi (ib, bb, data_in, fn);
 298       tag = streamer_read_record_start (ib);
 299     }
 300 }