1/* Routines for reading GIMPLE from a file stream.
2
3 Copyright (C) 2011-2017 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 "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
35/* Read a PHI function for basic block BB in function FN. DATA_IN is
36 the file being read. IB is the input block to use for reading. */
37
38static gphi *
39input_phi (struct lto_input_block *ib, basic_block bb, struct data_in *data_in,
40 struct function *fn)
41{
42 unsigned HOST_WIDE_INT ix;
43 tree phi_result;
44 int i, len;
45 gphi *result;
46
47 ix = streamer_read_uhwi (ib);
48 phi_result = (*SSANAMES (fn))[ix];
49 len = EDGE_COUNT (bb->preds);
50 result = create_phi_node (phi_result, bb);
51
52 /* We have to go through a lookup process here because the preds in the
53 reconstructed graph are generally in a different order than they
54 were in the original program. */
55 for (i = 0; i < len; i++)
56 {
57 tree def = stream_read_tree (ib, data_in);
58 int src_index = streamer_read_uhwi (ib);
59 bitpack_d bp = streamer_read_bitpack (ib);
60 /* Do not cache a location - we do not have API to get pointer to the
61 location in PHI statement and we may trigger reallocation. */
62 location_t arg_loc = stream_input_location_now (&bp, data_in);
63 basic_block sbb = BASIC_BLOCK_FOR_FN (fn, src_index);
64
65 edge e = NULL;
66 int j;
67
68 for (j = 0; j < len; j++)
69 if (EDGE_PRED (bb, j)->src == sbb)
70 {
71 e = EDGE_PRED (bb, j);
72 break;
73 }
74
75 add_phi_arg (result, def, e, arg_loc);
76 }
77
78 return result;
79}
80
81
82/* Read a statement with tag TAG in function FN from block IB using
83 descriptors in DATA_IN. */
84
85static gimple *
86input_gimple_stmt (struct lto_input_block *ib, struct data_in *data_in,
87 enum LTO_tags tag)
88{
89 gimple *stmt;
90 enum gimple_code code;
91 unsigned HOST_WIDE_INT num_ops;
92 size_t i;
93 struct bitpack_d bp;
94 bool has_hist;
95
96 code = lto_tag_to_gimple_code (tag);
97
98 /* Read the tuple header. */
99 bp = streamer_read_bitpack (ib);
100 num_ops = bp_unpack_var_len_unsigned (&bp);
101 stmt = gimple_alloc (code, num_ops);
102 stmt->no_warning = bp_unpack_value (&bp, 1);
103 if (is_gimple_assign (stmt))
104 stmt->nontemporal_move = bp_unpack_value (&bp, 1);
105 stmt->has_volatile_ops = bp_unpack_value (&bp, 1);
106 has_hist = bp_unpack_value (&bp, 1);
107 stmt->subcode = bp_unpack_var_len_unsigned (&bp);
108
109 /* Read location information. Caching here makes no sense until streamer
110 cache can handle the following gimple_set_block. */
111 gimple_set_location (stmt, stream_input_location_now (&bp, data_in));
112
113 /* Read lexical block reference. */
114 gimple_set_block (stmt, stream_read_tree (ib, data_in));
115
116 /* Read in all the operands. */
117 switch (code)
118 {
119 case GIMPLE_RESX:
120 gimple_resx_set_region (as_a <gresx *> (stmt),
121 streamer_read_hwi (ib));
122 break;
123
124 case GIMPLE_EH_MUST_NOT_THROW:
125 gimple_eh_must_not_throw_set_fndecl (
126 as_a <geh_mnt *> (stmt),
127 stream_read_tree (ib, data_in));
128 break;
129
130 case GIMPLE_EH_DISPATCH:
131 gimple_eh_dispatch_set_region (as_a <geh_dispatch *> (stmt),
132 streamer_read_hwi (ib));
133 break;
134
135 case GIMPLE_ASM:
136 {
137 /* FIXME lto. Move most of this into a new gimple_asm_set_string(). */
138 gasm *asm_stmt = as_a <gasm *> (stmt);
139 tree str;
140 asm_stmt->ni = streamer_read_uhwi (ib);
141 asm_stmt->no = streamer_read_uhwi (ib);
142 asm_stmt->nc = streamer_read_uhwi (ib);
143 asm_stmt->nl = streamer_read_uhwi (ib);
144 str = streamer_read_string_cst (data_in, ib);
145 asm_stmt->string = TREE_STRING_POINTER (str);
146 }
147 /* Fallthru */
148
149 case GIMPLE_ASSIGN:
150 case GIMPLE_CALL:
151 case GIMPLE_RETURN:
152 case GIMPLE_SWITCH:
153 case GIMPLE_LABEL:
154 case GIMPLE_COND:
155 case GIMPLE_GOTO:
156 case GIMPLE_DEBUG:
157 for (i = 0; i < num_ops; i++)
158 {
159 tree *opp, op = stream_read_tree (ib, data_in);
160 gimple_set_op (stmt, i, op);
161 if (!op)
162 continue;
163
164 opp = gimple_op_ptr (stmt, i);
165 if (TREE_CODE (*opp) == ADDR_EXPR)
166 opp = &TREE_OPERAND (*opp, 0);
167 while (handled_component_p (*opp))
168 opp = &TREE_OPERAND (*opp, 0);
169 /* At LTO output time we wrap all global decls in MEM_REFs to
170 allow seamless replacement with prevailing decls. Undo this
171 here if the prevailing decl allows for this.
172 ??? Maybe we should simply fold all stmts. */
173 if (TREE_CODE (*opp) == MEM_REF
174 && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
175 && integer_zerop (TREE_OPERAND (*opp, 1))
176 && (TREE_THIS_VOLATILE (*opp)
177 == TREE_THIS_VOLATILE
178 (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
179 && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
180 && (TREE_TYPE (*opp)
181 == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
182 && (TREE_TYPE (*opp)
183 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
184 *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
185 }
186 if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
187 {
188 if (gimple_call_internal_p (call_stmt))
189 gimple_call_set_internal_fn
190 (call_stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
191 else
192 gimple_call_set_fntype (call_stmt, stream_read_tree (ib, data_in));
193 }
194 break;
195
196 case GIMPLE_NOP:
197 case GIMPLE_PREDICT:
198 break;
199
200 case GIMPLE_TRANSACTION:
201 gimple_transaction_set_label_norm (as_a <gtransaction *> (stmt),
202 stream_read_tree (ib, data_in));
203 gimple_transaction_set_label_uninst (as_a <gtransaction *> (stmt),
204 stream_read_tree (ib, data_in));
205 gimple_transaction_set_label_over (as_a <gtransaction *> (stmt),
206 stream_read_tree (ib, data_in));
207 break;
208
209 default:
210 internal_error ("bytecode stream: unknown GIMPLE statement tag %s",
211 lto_tag_name (tag));
212 }
213
214 /* Update the properties of symbols, SSA names and labels associated
215 with STMT. */
216 if (code == GIMPLE_ASSIGN || code == GIMPLE_CALL)
217 {
218 tree lhs = gimple_get_lhs (stmt);
219 if (lhs && TREE_CODE (lhs) == SSA_NAME)
220 SSA_NAME_DEF_STMT (lhs) = stmt;
221 }
222 else if (code == GIMPLE_ASM)
223 {
224 gasm *asm_stmt = as_a <gasm *> (stmt);
225 unsigned i;
226
227 for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
228 {
229 tree op = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
230 if (TREE_CODE (op) == SSA_NAME)
231 SSA_NAME_DEF_STMT (op) = stmt;
232 }
233 }
234
235 /* Reset alias information. */
236 if (code == GIMPLE_CALL)
237 gimple_call_reset_alias_info (as_a <gcall *> (stmt));
238
239 /* Mark the statement modified so its operand vectors can be filled in. */
240 gimple_set_modified (stmt, true);
241 if (has_hist)
242 stream_in_histogram_value (ib, stmt);
243
244 return stmt;
245}
246
247
248/* Read a basic block with tag TAG from DATA_IN using input block IB.
249 FN is the function being processed. */
250
251void
252input_bb (struct lto_input_block *ib, enum LTO_tags tag,
253 struct data_in *data_in, struct function *fn,
254 int count_materialization_scale)
255{
256 unsigned int index;
257 basic_block bb;
258 gimple_stmt_iterator bsi;
259
260 /* This routine assumes that CFUN is set to FN, as it needs to call
261 basic GIMPLE routines that use CFUN. */
262 gcc_assert (cfun == fn);
263
264 index = streamer_read_uhwi (ib);
265 bb = BASIC_BLOCK_FOR_FN (fn, index);
266
267 bb->count = profile_count::stream_in (ib);
268 if (count_materialization_scale != REG_BR_PROB_BASE
269 && bb->count.ipa ().nonzero_p ())
270 bb->count
271 = bb->count.apply_scale (count_materialization_scale, REG_BR_PROB_BASE);
272 bb->flags = streamer_read_hwi (ib);
273
274 /* LTO_bb1 has statements. LTO_bb0 does not. */
275 if (tag == LTO_bb0)
276 return;
277
278 bsi = gsi_start_bb (bb);
279 tag = streamer_read_record_start (ib);
280 while (tag)
281 {
282 gimple *stmt = input_gimple_stmt (ib, data_in, tag);
283 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
284
285 /* After the statement, expect a 0 delimiter or the EH region
286 that the previous statement belongs to. */
287 tag = streamer_read_record_start (ib);
288 lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
289
290 if (tag == LTO_eh_region)
291 {
292 HOST_WIDE_INT region = streamer_read_hwi (ib);
293 gcc_assert (region == (int) region);
294 add_stmt_to_eh_lp (stmt, region);
295 }
296
297 tag = streamer_read_record_start (ib);
298 }
299
300 tag = streamer_read_record_start (ib);
301 while (tag)
302 {
303 input_phi (ib, bb, data_in, fn);
304 tag = streamer_read_record_start (ib);
305 }
306}
307