Mercurial > hg > CbC > CbC_gcc

comparison gcc/gimple-ssa-isolate-paths.c @ 131:84e7813d76e9

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gcc-8.2
author mir3636
date Thu, 25 Oct 2018 07:37:49 +0900
parents 04ced10e8804
children 1830386684a0
comparison
equal deleted inserted replaced
111:04ced10e8804 131:84e7813d76e9
1 /* Detect paths through the CFG which can never be executed in a conforming 1 /* Detect paths through the CFG which can never be executed in a conforming
2 program and isolate them. 2 program and isolate them.
3 3
4 Copyright (C) 2013-2017 Free Software Foundation, Inc. 4 Copyright (C) 2013-2018 Free Software Foundation, Inc.
5 5
6 This file is part of GCC. 6 This file is part of GCC.
7 7
8 GCC is free software; you can redistribute it and/or modify 8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by 9 it under the terms of the GNU General Public License as published by
136 { 136 {
137 gimple_stmt_iterator si, si2; 137 gimple_stmt_iterator si, si2;
138 edge_iterator ei; 138 edge_iterator ei;
139 edge e2; 139 edge e2;
140 bool impossible = true; 140 bool impossible = true;
141 profile_count count = e->count ();
141 142
142 for (si = gsi_start_bb (bb); gsi_stmt (si) != stmt; gsi_next (&si)) 143 for (si = gsi_start_bb (bb); gsi_stmt (si) != stmt; gsi_next (&si))
143 if (stmt_can_terminate_bb_p (gsi_stmt (si))) 144 if (stmt_can_terminate_bb_p (gsi_stmt (si)))
144 { 145 {
145 impossible = false; 146 impossible = false;
152 trap. Removing the outgoing edges is both an optimization and ensures 153 trap. Removing the outgoing edges is both an optimization and ensures
153 we don't need to do any PHI node updates. */ 154 we don't need to do any PHI node updates. */
154 if (!duplicate) 155 if (!duplicate)
155 { 156 {
156 duplicate = duplicate_block (bb, NULL, NULL); 157 duplicate = duplicate_block (bb, NULL, NULL);
157 bb->frequency = 0; 158 duplicate->count = profile_count::zero ();
158 bb->count = profile_count::zero ();
159 if (!ret_zero) 159 if (!ret_zero)
160 for (ei = ei_start (duplicate->succs); (e2 = ei_safe_edge (ei)); ) 160 for (ei = ei_start (duplicate->succs); (e2 = ei_safe_edge (ei)); )
161 remove_edge (e2); 161 remove_edge (e2);
162 } 162 }
163 bb->count -= count;
163 164
164 /* Complete the isolation step by redirecting E to reach DUPLICATE. */ 165 /* Complete the isolation step by redirecting E to reach DUPLICATE. */
165 e2 = redirect_edge_and_branch (e, duplicate); 166 e2 = redirect_edge_and_branch (e, duplicate);
166 if (e2) 167 if (e2)
167 { 168 {
168 flush_pending_stmts (e2); 169 flush_pending_stmts (e2);
169 170
170 /* Update profile only when redirection is really processed. */ 171 /* Update profile only when redirection is really processed. */
171 bb->frequency += EDGE_FREQUENCY (e); 172 bb->count += e->count ();
172 } 173 }
173 174
174 /* There may be more than one statement in DUPLICATE which exhibits 175 /* There may be more than one statement in DUPLICATE which exhibits
175 undefined behavior. Ultimately we want the first such statement in 176 undefined behavior. Ultimately we want the first such statement in
176 DUPLCIATE so that we're able to delete as much code as possible. 177 DUPLCIATE so that we're able to delete as much code as possible.
418 continue; 419 continue;
419 420
420 if (gimple_return_retval (return_stmt) != lhs) 421 if (gimple_return_retval (return_stmt) != lhs)
421 continue; 422 continue;
422 423
423 if (warning_at (gimple_location (use_stmt), 424 {
424 OPT_Wreturn_local_addr, 425 auto_diagnostic_group d;
425 "function may return address " 426 if (warning_at (gimple_location (use_stmt),
426 "of local variable")) 427 OPT_Wreturn_local_addr,
427 inform (DECL_SOURCE_LOCATION(valbase), 428 "function may return address "
428 "declared here"); 429 "of local variable"))
430 inform (DECL_SOURCE_LOCATION(valbase),
431 "declared here");
432 }
429 433
430 if (gimple_bb (use_stmt) == bb) 434 if (gimple_bb (use_stmt) == bb)
431 { 435 {
432 duplicate = isolate_path (bb, duplicate, e, 436 duplicate = isolate_path (bb, duplicate, e,
433 use_stmt, lhs, true); 437 use_stmt, lhs, true);
540 if (always_executed) 544 if (always_executed)
541 msg = N_("function returns address of local variable"); 545 msg = N_("function returns address of local variable");
542 else 546 else
543 msg = N_("function may return address of " 547 msg = N_("function may return address of "
544 "local variable"); 548 "local variable");
545 549 {
546 if (warning_at (gimple_location (stmt), 550 auto_diagnostic_group d;
547 OPT_Wreturn_local_addr, msg)) 551 if (warning_at (gimple_location (stmt),
548 inform (DECL_SOURCE_LOCATION(valbase), "declared here"); 552 OPT_Wreturn_local_addr, msg))
553 inform (DECL_SOURCE_LOCATION(valbase),
554 "declared here");
555 }
549 tree zero = build_zero_cst (TREE_TYPE (val)); 556 tree zero = build_zero_cst (TREE_TYPE (val));
550 gimple_return_set_retval (return_stmt, zero); 557 gimple_return_set_retval (return_stmt, zero);
551 update_stmt (stmt); 558 update_stmt (stmt);
552 } 559 }
553 } 560 }