1/* Routines for emitting GIMPLE to a file stream.
2
3   Copyright (C) 2011-2020 Free Software Foundation, Inc.
4   Contributed by Diego Novillo <dnovillo@google.com>
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify it under
9the terms of the GNU General Public License as published by the Free
10Software Foundation; either version 3, or (at your option) any later
11version.
12
13GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14WARRANTY; without even the implied warranty of MERCHANTABILITY or
15FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16for more details.
17
18You should have received a copy of the GNU General Public License
19along 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 "backend.h"
26#include "tree.h"
27#include "gimple.h"
28#include "gimple-ssa.h"
29#include "gimple-streamer.h"
30#include "tree-eh.h"
31#include "gimple-iterator.h"
32#include "cgraph.h"
33#include "value-prof.h"
34#include "gimple-pretty-print.h"
35
36/* Output PHI function PHI to the main stream in OB.  */
37
38static void
39output_phi (struct output_block *ob, gphi *phi)
40{
41  unsigned i, len = gimple_phi_num_args (phi);
42
43  streamer_write_record_start (ob, lto_gimple_code_to_tag (GIMPLE_PHI));
44  streamer_write_uhwi (ob, SSA_NAME_VERSION (PHI_RESULT (phi)));
45
46  for (i = 0; i < len; i++)
47    {
48      stream_write_tree (ob, gimple_phi_arg_def (phi, i), true);
49      streamer_write_uhwi (ob, gimple_phi_arg_edge (phi, i)->src->index);
50      bitpack_d bp = bitpack_create (ob->main_stream);
51      location_t loc = gimple_phi_arg_location (phi, i);
52      stream_output_location_and_block (ob, &bp, loc);
53    }
54}
55
56
57/* Emit statement STMT on the main stream of output block OB.  */
58
59static void
60output_gimple_stmt (struct output_block *ob, struct function *fn, gimple *stmt)
61{
62  unsigned i;
63  enum gimple_code code;
64  enum LTO_tags tag;
65  struct bitpack_d bp;
66  histogram_value hist;
67
68  /* Emit identifying tag.  */
69  code = gimple_code (stmt);
70  tag = lto_gimple_code_to_tag (code);
71  streamer_write_record_start (ob, tag);
72
73  /* Emit the tuple header.  */
74  bp = bitpack_create (ob->main_stream);
75  bp_pack_var_len_unsigned (&bp, gimple_num_ops (stmt));
76  bp_pack_value (&bp, gimple_no_warning_p (stmt), 1);
77  if (is_gimple_assign (stmt))
78    bp_pack_value (&bp,
79		   gimple_assign_nontemporal_move_p (
80		     as_a <gassign *> (stmt)),
81		   1);
82  bp_pack_value (&bp, gimple_has_volatile_ops (stmt), 1);
83  hist = gimple_histogram_value (fn, stmt);
84  bp_pack_value (&bp, hist != NULL, 1);
85  bp_pack_var_len_unsigned (&bp, stmt->subcode);
86
87  /* Emit location information for the statement, including gimple_block.  */
88  stream_output_location_and_block (ob, &bp, gimple_location (stmt));
89
90  /* Emit the operands.  */
91  switch (gimple_code (stmt))
92    {
93    case GIMPLE_RESX:
94      streamer_write_hwi (ob, gimple_resx_region (as_a <gresx *> (stmt)));
95      break;
96
97    case GIMPLE_EH_MUST_NOT_THROW:
98      stream_write_tree (ob,
99			 gimple_eh_must_not_throw_fndecl (
100			   as_a <geh_mnt *> (stmt)),
101			 true);
102      break;
103
104    case GIMPLE_EH_DISPATCH:
105      streamer_write_hwi (ob,
106			  gimple_eh_dispatch_region (
107			    as_a <geh_dispatch *> (stmt)));
108      break;
109
110    case GIMPLE_ASM:
111      {
112	gasm *asm_stmt = as_a <gasm *> (stmt);
113	streamer_write_uhwi (ob, gimple_asm_ninputs (asm_stmt));
114	streamer_write_uhwi (ob, gimple_asm_noutputs (asm_stmt));
115	streamer_write_uhwi (ob, gimple_asm_nclobbers (asm_stmt));
116	streamer_write_uhwi (ob, gimple_asm_nlabels (asm_stmt));
117	streamer_write_string (ob, ob->main_stream,
118			       gimple_asm_string (asm_stmt), true);
119      }
120      /* Fallthru  */
121
122    case GIMPLE_ASSIGN:
123    case GIMPLE_CALL:
124    case GIMPLE_RETURN:
125    case GIMPLE_SWITCH:
126    case GIMPLE_LABEL:
127    case GIMPLE_COND:
128    case GIMPLE_GOTO:
129    case GIMPLE_DEBUG:
130      for (i = 0; i < gimple_num_ops (stmt); i++)
131	{
132	  tree op = gimple_op (stmt, i);
133	  tree *basep = NULL;
134	  /* Wrap all uses of non-automatic variables inside MEM_REFs
135	     so that we do not have to deal with type mismatches on
136	     merged symbols during IL read in.  The first operand
137	     of GIMPLE_DEBUG must be a decl, not MEM_REF, though.  */
138	  if (!flag_wpa && op && (i || !is_gimple_debug (stmt)))
139	    {
140	      basep = &op;
141	      if (TREE_CODE (*basep) == ADDR_EXPR)
142		basep = &TREE_OPERAND (*basep, 0);
143	      while (handled_component_p (*basep))
144		basep = &TREE_OPERAND (*basep, 0);
145	      if (VAR_P (*basep)
146		  && !auto_var_in_fn_p (*basep, fn->decl)
147		  && !DECL_REGISTER (*basep))
148		{
149		  bool volatilep = TREE_THIS_VOLATILE (*basep);
150		  tree ptrtype = build_pointer_type (TREE_TYPE (*basep));
151		  *basep = build2 (MEM_REF, TREE_TYPE (*basep),
152				   build1 (ADDR_EXPR, ptrtype, *basep),
153				   build_int_cst (ptrtype, 0));
154		  TREE_THIS_VOLATILE (*basep) = volatilep;
155		}
156	      else
157		basep = NULL;
158	    }
159	  stream_write_tree (ob, op, true);
160	  /* Restore the original base if we wrapped it inside a MEM_REF.  */
161	  if (basep)
162	    *basep = TREE_OPERAND (TREE_OPERAND (*basep, 0), 0);
163	}
164      if (is_gimple_call (stmt))
165	{
166	  if (gimple_call_internal_p (stmt))
167	    streamer_write_enum (ob->main_stream, internal_fn,
168				 IFN_LAST, gimple_call_internal_fn (stmt));
169	  else
170	    stream_write_tree (ob, gimple_call_fntype (stmt), true);
171	}
172      break;
173
174    case GIMPLE_NOP:
175    case GIMPLE_PREDICT:
176      break;
177
178    case GIMPLE_TRANSACTION:
179      {
180	gtransaction *txn = as_a <gtransaction *> (stmt);
181	gcc_assert (gimple_transaction_body (txn) == NULL);
182	stream_write_tree (ob, gimple_transaction_label_norm (txn), true);
183	stream_write_tree (ob, gimple_transaction_label_uninst (txn), true);
184	stream_write_tree (ob, gimple_transaction_label_over (txn), true);
185      }
186      break;
187
188    default:
189      gcc_unreachable ();
190    }
191  if (hist)
192    stream_out_histogram_value (ob, hist);
193}
194
195
196/* Output a basic block BB to the main stream in OB for this FN.  */
197
198void
199output_bb (struct output_block *ob, basic_block bb, struct function *fn)
200{
201  gimple_stmt_iterator bsi = gsi_start_bb (bb);
202
203  streamer_write_record_start (ob,
204			       (!gsi_end_p (bsi)) || phi_nodes (bb)
205			        ? LTO_bb1
206				: LTO_bb0);
207
208  streamer_write_uhwi (ob, bb->index);
209  bb->count.stream_out (ob);
210  streamer_write_hwi (ob, bb->flags);
211  streamer_write_hwi (ob, bb->discriminator);
212
213  if (!gsi_end_p (bsi) || phi_nodes (bb))
214    {
215      /* Output the statements.  The list of statements is terminated
216	 with a zero.  */
217      for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
218	{
219	  int region;
220	  gimple *stmt = gsi_stmt (bsi);
221	  if (streamer_dump_file)
222	    {
223	      fprintf (streamer_dump_file, "  Streaming gimple stmt ");
224	      print_gimple_stmt (streamer_dump_file, stmt, 0, TDF_SLIM);
225	    }
226
227	  output_gimple_stmt (ob, fn, stmt);
228
229	  /* Emit the EH region holding STMT.  */
230	  region = lookup_stmt_eh_lp_fn (fn, stmt);
231	  if (region != 0)
232	    {
233	      streamer_write_record_start (ob, LTO_eh_region);
234	      streamer_write_hwi (ob, region);
235	    }
236	  else
237	    streamer_write_record_start (ob, LTO_null);
238	}
239
240      streamer_write_record_start (ob, LTO_null);
241
242      for (gphi_iterator psi = gsi_start_phis (bb);
243	   !gsi_end_p (psi);
244	   gsi_next (&psi))
245	{
246	  gphi *phi = psi.phi ();
247
248	  /* Only emit PHIs for gimple registers.  PHI nodes for .MEM
249	     will be filled in on reading when the SSA form is
250	     updated.  */
251	  if (!virtual_operand_p (gimple_phi_result (phi)))
252	    output_phi (ob, phi);
253	}
254
255      streamer_write_record_start (ob, LTO_null);
256    }
257}
258