1 /* Routines for reading GIMPLE from a file stream.
2
3 Copyright (C) 2011-2020 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 "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
38 static gphi *
input_phi(class lto_input_block * ib,basic_block bb,class data_in * data_in,struct function * fn)39 input_phi (class lto_input_block *ib, basic_block bb, class 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 basic_block sbb = BASIC_BLOCK_FOR_FN (fn, src_index);
61 edge e = NULL;
62 int j;
63
64 for (j = 0; j < len; j++)
65 if (EDGE_PRED (bb, j)->src == sbb)
66 {
67 e = EDGE_PRED (bb, j);
68 break;
69 }
70
71 add_phi_arg (result, def, e, UNKNOWN_LOCATION);
72 /* Read location and lexical block information. */
73 location_t *arg_locp = gimple_phi_arg_location_ptr (result, e->dest_idx);
74 data_in->location_cache.input_location_and_block (arg_locp, &bp, ib,
75 data_in);
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
85 static gimple *
input_gimple_stmt(class lto_input_block * ib,class data_in * data_in,enum LTO_tags tag)86 input_gimple_stmt (class lto_input_block *ib, class 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 and lexical block information. */
110 data_in->location_cache.input_location_and_block (gimple_location_ptr (stmt),
111 &bp, ib, data_in);
112
113 /* Read in all the operands. */
114 switch (code)
115 {
116 case GIMPLE_RESX:
117 gimple_resx_set_region (as_a <gresx *> (stmt),
118 streamer_read_hwi (ib));
119 break;
120
121 case GIMPLE_EH_MUST_NOT_THROW:
122 gimple_eh_must_not_throw_set_fndecl (
123 as_a <geh_mnt *> (stmt),
124 stream_read_tree (ib, data_in));
125 break;
126
127 case GIMPLE_EH_DISPATCH:
128 gimple_eh_dispatch_set_region (as_a <geh_dispatch *> (stmt),
129 streamer_read_hwi (ib));
130 break;
131
132 case GIMPLE_ASM:
133 {
134 /* FIXME lto. Move most of this into a new gimple_asm_set_string(). */
135 gasm *asm_stmt = as_a <gasm *> (stmt);
136 tree str;
137 asm_stmt->ni = streamer_read_uhwi (ib);
138 asm_stmt->no = streamer_read_uhwi (ib);
139 asm_stmt->nc = streamer_read_uhwi (ib);
140 asm_stmt->nl = streamer_read_uhwi (ib);
141 str = streamer_read_string_cst (data_in, ib);
142 asm_stmt->string = TREE_STRING_POINTER (str);
143 }
144 /* Fallthru */
145
146 case GIMPLE_ASSIGN:
147 case GIMPLE_CALL:
148 case GIMPLE_RETURN:
149 case GIMPLE_SWITCH:
150 case GIMPLE_LABEL:
151 case GIMPLE_COND:
152 case GIMPLE_GOTO:
153 case GIMPLE_DEBUG:
154 for (i = 0; i < num_ops; i++)
155 {
156 tree *opp, op = stream_read_tree (ib, data_in);
157 gimple_set_op (stmt, i, op);
158 if (!op)
159 continue;
160
161 opp = gimple_op_ptr (stmt, i);
162 if (TREE_CODE (*opp) == ADDR_EXPR)
163 opp = &TREE_OPERAND (*opp, 0);
164 while (handled_component_p (*opp))
165 opp = &TREE_OPERAND (*opp, 0);
166 /* At LTO output time we wrap all global decls in MEM_REFs to
167 allow seamless replacement with prevailing decls. Undo this
168 here if the prevailing decl allows for this.
169 ??? Maybe we should simply fold all stmts. */
170 if (TREE_CODE (*opp) == MEM_REF
171 && TREE_CODE (TREE_OPERAND (*opp, 0)) == ADDR_EXPR
172 && integer_zerop (TREE_OPERAND (*opp, 1))
173 && (TREE_THIS_VOLATILE (*opp)
174 == TREE_THIS_VOLATILE
175 (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0)))
176 && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*opp, 1)))
177 && (TREE_TYPE (*opp)
178 == TREE_TYPE (TREE_TYPE (TREE_OPERAND (*opp, 1))))
179 && (TREE_TYPE (*opp)
180 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (*opp, 0), 0))))
181 *opp = TREE_OPERAND (TREE_OPERAND (*opp, 0), 0);
182 }
183 if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
184 {
185 if (gimple_call_internal_p (call_stmt))
186 gimple_call_set_internal_fn
187 (call_stmt, streamer_read_enum (ib, internal_fn, IFN_LAST));
188 else
189 gimple_call_set_fntype (call_stmt, stream_read_tree (ib, data_in));
190 }
191 break;
192
193 case GIMPLE_NOP:
194 case GIMPLE_PREDICT:
195 break;
196
197 case GIMPLE_TRANSACTION:
198 gimple_transaction_set_label_norm (as_a <gtransaction *> (stmt),
199 stream_read_tree (ib, data_in));
200 gimple_transaction_set_label_uninst (as_a <gtransaction *> (stmt),
201 stream_read_tree (ib, data_in));
202 gimple_transaction_set_label_over (as_a <gtransaction *> (stmt),
203 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 gasm *asm_stmt = as_a <gasm *> (stmt);
222 unsigned i;
223
224 for (i = 0; i < gimple_asm_noutputs (asm_stmt); i++)
225 {
226 tree op = TREE_VALUE (gimple_asm_output_op (asm_stmt, i));
227 if (TREE_CODE (op) == SSA_NAME)
228 SSA_NAME_DEF_STMT (op) = stmt;
229 }
230 }
231
232 /* Reset alias information. */
233 if (code == GIMPLE_CALL)
234 gimple_call_reset_alias_info (as_a <gcall *> (stmt));
235
236 /* Mark the statement modified so its operand vectors can be filled in. */
237 gimple_set_modified (stmt, true);
238 if (has_hist)
239 stream_in_histogram_value (ib, stmt);
240
241 return stmt;
242 }
243
244
245 /* Read a basic block with tag TAG from DATA_IN using input block IB.
246 FN is the function being processed. */
247
248 void
input_bb(class lto_input_block * ib,enum LTO_tags tag,class data_in * data_in,struct function * fn,int count_materialization_scale)249 input_bb (class lto_input_block *ib, enum LTO_tags tag,
250 class data_in *data_in, struct function *fn,
251 int count_materialization_scale)
252 {
253 unsigned int index;
254 basic_block bb;
255 gimple_stmt_iterator bsi;
256
257 /* This routine assumes that CFUN is set to FN, as it needs to call
258 basic GIMPLE routines that use CFUN. */
259 gcc_assert (cfun == fn);
260
261 index = streamer_read_uhwi (ib);
262 bb = BASIC_BLOCK_FOR_FN (fn, index);
263
264 bb->count = profile_count::stream_in (ib);
265 if (count_materialization_scale != REG_BR_PROB_BASE
266 && bb->count.ipa ().nonzero_p ())
267 bb->count
268 = bb->count.apply_scale (count_materialization_scale, REG_BR_PROB_BASE);
269 bb->flags = streamer_read_hwi (ib);
270 bb->discriminator = streamer_read_hwi (ib);
271
272 /* LTO_bb1 has statements. LTO_bb0 does not. */
273 if (tag == LTO_bb0)
274 return;
275
276 bsi = gsi_start_bb (bb);
277 tag = streamer_read_record_start (ib);
278 while (tag)
279 {
280 gimple *stmt = input_gimple_stmt (ib, data_in, tag);
281 gsi_insert_after (&bsi, stmt, GSI_NEW_STMT);
282
283 /* After the statement, expect a 0 delimiter or the EH region
284 that the previous statement belongs to. */
285 tag = streamer_read_record_start (ib);
286 lto_tag_check_set (tag, 2, LTO_eh_region, LTO_null);
287
288 if (tag == LTO_eh_region)
289 {
290 HOST_WIDE_INT region = streamer_read_hwi (ib);
291 gcc_assert (region == (int) region);
292 add_stmt_to_eh_lp (stmt, region);
293 }
294
295 tag = streamer_read_record_start (ib);
296 }
297
298 tag = streamer_read_record_start (ib);
299 while (tag)
300 {
301 input_phi (ib, bb, data_in, fn);
302 tag = streamer_read_record_start (ib);
303 }
304 }
305