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