1 /* 2 * Copyright (c) 1998, 2014, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "ci/ciCallSite.hpp" 27 #include "ci/ciMethodHandle.hpp" 28 #include "classfile/vmSymbols.hpp" 29 #include "compiler/compileBroker.hpp" 30 #include "compiler/compileLog.hpp" 31 #include "interpreter/linkResolver.hpp" 32 #include "opto/addnode.hpp" 33 #include "opto/callGenerator.hpp" 34 #include "opto/castnode.hpp" 35 #include "opto/cfgnode.hpp" 36 #include "opto/mulnode.hpp" 37 #include "opto/parse.hpp" 38 #include "opto/rootnode.hpp" 39 #include "opto/runtime.hpp" 40 #include "opto/subnode.hpp" 41 #include "prims/nativeLookup.hpp" 42 #include "runtime/sharedRuntime.hpp" 43 44 void trace_type_profile(Compile* C, ciMethod *method, int depth, int bci, ciMethod *prof_method, ciKlass *prof_klass, int site_count, int receiver_count) { 45 if (TraceTypeProfile || C->print_inlining()) { 46 outputStream* out = tty; 47 if (!C->print_inlining()) { 48 if (NOT_PRODUCT(!PrintOpto &&) !PrintCompilation) { 49 method->print_short_name(); 50 tty->cr(); 51 } 52 CompileTask::print_inlining_tty(prof_method, depth, bci); 53 } else { 54 out = C->print_inlining_stream(); 55 } 56 CompileTask::print_inline_indent(depth, out); 57 out->print(" \\-> TypeProfile (%d/%d counts) = ", receiver_count, site_count); 58 stringStream ss; 59 prof_klass->name()->print_symbol_on(&ss); 60 out->print("%s", ss.as_string()); 61 out->cr(); 62 } 63 } 64 65 CallGenerator* Compile::call_generator(ciMethod* callee, int vtable_index, bool call_does_dispatch, 66 JVMState* jvms, bool allow_inline, 67 float prof_factor, ciKlass* speculative_receiver_type, 68 bool allow_intrinsics, bool delayed_forbidden) { 69 ciMethod* caller = jvms->method(); 70 int bci = jvms->bci(); 71 Bytecodes::Code bytecode = caller->java_code_at_bci(bci); 72 guarantee(callee != NULL, "failed method resolution"); 73 74 // Dtrace currently doesn't work unless all calls are vanilla 75 if (env()->dtrace_method_probes()) { 76 allow_inline = false; 77 } 78 79 // Note: When we get profiling during stage-1 compiles, we want to pull 80 // from more specific profile data which pertains to this inlining. 81 // Right now, ignore the information in jvms->caller(), and do method[bci]. 82 ciCallProfile profile = caller->call_profile_at_bci(bci); 83 84 // See how many times this site has been invoked. 85 int site_count = profile.count(); 86 int receiver_count = -1; 87 if (call_does_dispatch && UseTypeProfile && profile.has_receiver(0)) { 88 // Receivers in the profile structure are ordered by call counts 89 // so that the most called (major) receiver is profile.receiver(0). 90 receiver_count = profile.receiver_count(0); 91 } 92 93 CompileLog* log = this->log(); 94 if (log != NULL) { 95 int rid = (receiver_count >= 0)? log->identify(profile.receiver(0)): -1; 96 int r2id = (rid != -1 && profile.has_receiver(1))? log->identify(profile.receiver(1)):-1; 97 log->begin_elem("call method='%d' count='%d' prof_factor='%f'", 98 log->identify(callee), site_count, prof_factor); 99 if (call_does_dispatch) log->print(" virtual='1'"); 100 if (allow_inline) log->print(" inline='1'"); 101 if (receiver_count >= 0) { 102 log->print(" receiver='%d' receiver_count='%d'", rid, receiver_count); 103 if (profile.has_receiver(1)) { 104 log->print(" receiver2='%d' receiver2_count='%d'", r2id, profile.receiver_count(1)); 105 } 106 } 107 if (callee->is_method_handle_intrinsic()) { 108 log->print(" method_handle_intrinsic='1'"); 109 } 110 log->end_elem(); 111 } 112 113 // Special case the handling of certain common, profitable library 114 // methods. If these methods are replaced with specialized code, 115 // then we return it as the inlined version of the call. 116 // We do this before the strict f.p. check below because the 117 // intrinsics handle strict f.p. correctly. 118 CallGenerator* cg_intrinsic = NULL; 119 if (allow_inline && allow_intrinsics) { 120 CallGenerator* cg = find_intrinsic(callee, call_does_dispatch); 121 if (cg != NULL) { 122 if (cg->is_predicated()) { 123 // Code without intrinsic but, hopefully, inlined. 124 CallGenerator* inline_cg = this->call_generator(callee, 125 vtable_index, call_does_dispatch, jvms, allow_inline, prof_factor, speculative_receiver_type, false); 126 if (inline_cg != NULL) { 127 cg = CallGenerator::for_predicated_intrinsic(cg, inline_cg); 128 } 129 } 130 131 // If intrinsic does the virtual dispatch, we try to use the type profile 132 // first, and hopefully inline it as the regular virtual call below. 133 // We will retry the intrinsic if nothing had claimed it afterwards. 134 if (cg->does_virtual_dispatch()) { 135 cg_intrinsic = cg; 136 cg = NULL; 137 } else { 138 return cg; 139 } 140 } 141 } 142 143 // Do method handle calls. 144 // NOTE: This must happen before normal inlining logic below since 145 // MethodHandle.invoke* are native methods which obviously don't 146 // have bytecodes and so normal inlining fails. 147 if (callee->is_method_handle_intrinsic()) { 148 CallGenerator* cg = CallGenerator::for_method_handle_call(jvms, caller, callee, delayed_forbidden); 149 assert(cg == NULL || !delayed_forbidden || !cg->is_late_inline() || cg->is_mh_late_inline(), "unexpected CallGenerator"); 150 return cg; 151 } 152 153 // Do not inline strict fp into non-strict code, or the reverse 154 if (caller->is_strict() ^ callee->is_strict()) { 155 allow_inline = false; 156 } 157 158 // Attempt to inline... 159 if (allow_inline) { 160 // The profile data is only partly attributable to this caller, 161 // scale back the call site information. 162 float past_uses = jvms->method()->scale_count(site_count, prof_factor); 163 // This is the number of times we expect the call code to be used. 164 float expected_uses = past_uses; 165 166 // Try inlining a bytecoded method: 167 if (!call_does_dispatch) { 168 InlineTree* ilt = InlineTree::find_subtree_from_root(this->ilt(), jvms->caller(), jvms->method()); 169 WarmCallInfo scratch_ci; 170 bool should_delay = false; 171 WarmCallInfo* ci = ilt->ok_to_inline(callee, jvms, profile, &scratch_ci, should_delay); 172 assert(ci != &scratch_ci, "do not let this pointer escape"); 173 bool allow_inline = (ci != NULL && !ci->is_cold()); 174 bool require_inline = (allow_inline && ci->is_hot()); 175 176 if (allow_inline) { 177 CallGenerator* cg = CallGenerator::for_inline(callee, expected_uses); 178 179 if (require_inline && cg != NULL) { 180 // Delay the inlining of this method to give us the 181 // opportunity to perform some high level optimizations 182 // first. 183 if (should_delay_string_inlining(callee, jvms)) { 184 assert(!delayed_forbidden, "strange"); 185 return CallGenerator::for_string_late_inline(callee, cg); 186 } else if (should_delay_boxing_inlining(callee, jvms)) { 187 assert(!delayed_forbidden, "strange"); 188 return CallGenerator::for_boxing_late_inline(callee, cg); 189 } else if ((should_delay || AlwaysIncrementalInline) && !delayed_forbidden) { 190 return CallGenerator::for_late_inline(callee, cg); 191 } 192 } 193 if (cg == NULL || should_delay) { 194 // Fall through. 195 } else if (require_inline || !InlineWarmCalls) { 196 return cg; 197 } else { 198 CallGenerator* cold_cg = call_generator(callee, vtable_index, call_does_dispatch, jvms, false, prof_factor); 199 return CallGenerator::for_warm_call(ci, cold_cg, cg); 200 } 201 } 202 } 203 204 // Try using the type profile. 205 if (call_does_dispatch && site_count > 0 && receiver_count > 0) { 206 // The major receiver's count >= TypeProfileMajorReceiverPercent of site_count. 207 bool have_major_receiver = (100.*profile.receiver_prob(0) >= (float)TypeProfileMajorReceiverPercent); 208 ciMethod* receiver_method = NULL; 209 210 int morphism = profile.morphism(); 211 if (speculative_receiver_type != NULL) { 212 // We have a speculative type, we should be able to resolve 213 // the call. We do that before looking at the profiling at 214 // this invoke because it may lead to bimorphic inlining which 215 // a speculative type should help us avoid. 216 receiver_method = callee->resolve_invoke(jvms->method()->holder(), 217 speculative_receiver_type); 218 if (receiver_method == NULL) { 219 speculative_receiver_type = NULL; 220 } else { 221 morphism = 1; 222 } 223 } 224 if (receiver_method == NULL && 225 (have_major_receiver || morphism == 1 || 226 (morphism == 2 && UseBimorphicInlining))) { 227 // receiver_method = profile.method(); 228 // Profiles do not suggest methods now. Look it up in the major receiver. 229 receiver_method = callee->resolve_invoke(jvms->method()->holder(), 230 profile.receiver(0)); 231 } 232 if (receiver_method != NULL) { 233 // The single majority receiver sufficiently outweighs the minority. 234 CallGenerator* hit_cg = this->call_generator(receiver_method, 235 vtable_index, !call_does_dispatch, jvms, allow_inline, prof_factor); 236 if (hit_cg != NULL) { 237 // Look up second receiver. 238 CallGenerator* next_hit_cg = NULL; 239 ciMethod* next_receiver_method = NULL; 240 if (morphism == 2 && UseBimorphicInlining) { 241 next_receiver_method = callee->resolve_invoke(jvms->method()->holder(), 242 profile.receiver(1)); 243 if (next_receiver_method != NULL) { 244 next_hit_cg = this->call_generator(next_receiver_method, 245 vtable_index, !call_does_dispatch, jvms, 246 allow_inline, prof_factor); 247 if (next_hit_cg != NULL && !next_hit_cg->is_inline() && 248 have_major_receiver && UseOnlyInlinedBimorphic) { 249 // Skip if we can't inline second receiver's method 250 next_hit_cg = NULL; 251 } 252 } 253 } 254 CallGenerator* miss_cg; 255 Deoptimization::DeoptReason reason = morphism == 2 ? 256 Deoptimization::Reason_bimorphic : Deoptimization::reason_class_check(speculative_receiver_type != NULL); 257 if ((morphism == 1 || (morphism == 2 && next_hit_cg != NULL)) && 258 !too_many_traps(jvms->method(), jvms->bci(), reason) 259 ) { 260 // Generate uncommon trap for class check failure path 261 // in case of monomorphic or bimorphic virtual call site. 262 miss_cg = CallGenerator::for_uncommon_trap(callee, reason, 263 Deoptimization::Action_maybe_recompile); 264 } else { 265 // Generate virtual call for class check failure path 266 // in case of polymorphic virtual call site. 267 miss_cg = CallGenerator::for_virtual_call(callee, vtable_index); 268 } 269 if (miss_cg != NULL) { 270 if (next_hit_cg != NULL) { 271 assert(speculative_receiver_type == NULL, "shouldn't end up here if we used speculation"); 272 trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), next_receiver_method, profile.receiver(1), site_count, profile.receiver_count(1)); 273 // We don't need to record dependency on a receiver here and below. 274 // Whenever we inline, the dependency is added by Parse::Parse(). 275 miss_cg = CallGenerator::for_predicted_call(profile.receiver(1), miss_cg, next_hit_cg, PROB_MAX); 276 } 277 if (miss_cg != NULL) { 278 trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), receiver_method, profile.receiver(0), site_count, receiver_count); 279 ciKlass* k = speculative_receiver_type != NULL ? speculative_receiver_type : profile.receiver(0); 280 float hit_prob = speculative_receiver_type != NULL ? 1.0 : profile.receiver_prob(0); 281 CallGenerator* cg = CallGenerator::for_predicted_call(k, miss_cg, hit_cg, hit_prob); 282 if (cg != NULL) return cg; 283 } 284 } 285 } 286 } 287 } 288 } 289 290 // Nothing claimed the intrinsic, we go with straight-forward inlining 291 // for already discovered intrinsic. 292 if (allow_inline && allow_intrinsics && cg_intrinsic != NULL) { 293 assert(cg_intrinsic->does_virtual_dispatch(), "sanity"); 294 return cg_intrinsic; 295 } 296 297 // There was no special inlining tactic, or it bailed out. 298 // Use a more generic tactic, like a simple call. 299 if (call_does_dispatch) { 300 const char* msg = "virtual call"; 301 if (PrintInlining) print_inlining(callee, jvms->depth() - 1, jvms->bci(), msg); 302 C->log_inline_failure(msg); 303 return CallGenerator::for_virtual_call(callee, vtable_index); 304 } else { 305 // Class Hierarchy Analysis or Type Profile reveals a unique target, 306 // or it is a static or special call. 307 return CallGenerator::for_direct_call(callee, should_delay_inlining(callee, jvms)); 308 } 309 } 310 311 // Return true for methods that shouldn't be inlined early so that 312 // they are easier to analyze and optimize as intrinsics. 313 bool Compile::should_delay_string_inlining(ciMethod* call_method, JVMState* jvms) { 314 if (has_stringbuilder()) { 315 316 if ((call_method->holder() == C->env()->StringBuilder_klass() || 317 call_method->holder() == C->env()->StringBuffer_klass()) && 318 (jvms->method()->holder() == C->env()->StringBuilder_klass() || 319 jvms->method()->holder() == C->env()->StringBuffer_klass())) { 320 // Delay SB calls only when called from non-SB code 321 return false; 322 } 323 324 switch (call_method->intrinsic_id()) { 325 case vmIntrinsics::_StringBuilder_void: 326 case vmIntrinsics::_StringBuilder_int: 327 case vmIntrinsics::_StringBuilder_String: 328 case vmIntrinsics::_StringBuilder_append_char: 329 case vmIntrinsics::_StringBuilder_append_int: 330 case vmIntrinsics::_StringBuilder_append_String: 331 case vmIntrinsics::_StringBuilder_toString: 332 case vmIntrinsics::_StringBuffer_void: 333 case vmIntrinsics::_StringBuffer_int: 334 case vmIntrinsics::_StringBuffer_String: 335 case vmIntrinsics::_StringBuffer_append_char: 336 case vmIntrinsics::_StringBuffer_append_int: 337 case vmIntrinsics::_StringBuffer_append_String: 338 case vmIntrinsics::_StringBuffer_toString: 339 case vmIntrinsics::_Integer_toString: 340 return true; 341 342 case vmIntrinsics::_String_String: 343 { 344 Node* receiver = jvms->map()->in(jvms->argoff() + 1); 345 if (receiver->is_Proj() && receiver->in(0)->is_CallStaticJava()) { 346 CallStaticJavaNode* csj = receiver->in(0)->as_CallStaticJava(); 347 ciMethod* m = csj->method(); 348 if (m != NULL && 349 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString || 350 m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString)) 351 // Delay String.<init>(new SB()) 352 return true; 353 } 354 return false; 355 } 356 357 default: 358 return false; 359 } 360 } 361 return false; 362 } 363 364 bool Compile::should_delay_boxing_inlining(ciMethod* call_method, JVMState* jvms) { 365 if (eliminate_boxing() && call_method->is_boxing_method()) { 366 set_has_boxed_value(true); 367 return aggressive_unboxing(); 368 } 369 return false; 370 } 371 372 // uncommon-trap call-sites where callee is unloaded, uninitialized or will not link 373 bool Parse::can_not_compile_call_site(ciMethod *dest_method, ciInstanceKlass* klass) { 374 // Additional inputs to consider... 375 // bc = bc() 376 // caller = method() 377 // iter().get_method_holder_index() 378 assert( dest_method->is_loaded(), "ciTypeFlow should not let us get here" ); 379 // Interface classes can be loaded & linked and never get around to 380 // being initialized. Uncommon-trap for not-initialized static or 381 // v-calls. Let interface calls happen. 382 ciInstanceKlass* holder_klass = dest_method->holder(); 383 if (!holder_klass->is_being_initialized() && 384 !holder_klass->is_initialized() && 385 !holder_klass->is_interface()) { 386 uncommon_trap(Deoptimization::Reason_uninitialized, 387 Deoptimization::Action_reinterpret, 388 holder_klass); 389 return true; 390 } 391 392 assert(dest_method->is_loaded(), "dest_method: typeflow responsibility"); 393 return false; 394 } 395 396 397 //------------------------------do_call---------------------------------------- 398 // Handle your basic call. Inline if we can & want to, else just setup call. 399 void Parse::do_call() { 400 // It's likely we are going to add debug info soon. 401 // Also, if we inline a guy who eventually needs debug info for this JVMS, 402 // our contribution to it is cleaned up right here. 403 kill_dead_locals(); 404 405 C->print_inlining_assert_ready(); 406 407 // Set frequently used booleans 408 const bool is_virtual = bc() == Bytecodes::_invokevirtual; 409 const bool is_virtual_or_interface = is_virtual || bc() == Bytecodes::_invokeinterface; 410 const bool has_receiver = Bytecodes::has_receiver(bc()); 411 412 // Find target being called 413 bool will_link; 414 ciSignature* declared_signature = NULL; 415 ciMethod* orig_callee = iter().get_method(will_link, &declared_signature); // callee in the bytecode 416 ciInstanceKlass* holder_klass = orig_callee->holder(); 417 ciKlass* holder = iter().get_declared_method_holder(); 418 ciInstanceKlass* klass = ciEnv::get_instance_klass_for_declared_method_holder(holder); 419 assert(declared_signature != NULL, "cannot be null"); 420 421 // Bump max node limit for JSR292 users 422 if (bc() == Bytecodes::_invokedynamic || orig_callee->is_method_handle_intrinsic()) { 423 C->set_max_node_limit(3*MaxNodeLimit); 424 } 425 426 // uncommon-trap when callee is unloaded, uninitialized or will not link 427 // bailout when too many arguments for register representation 428 if (!will_link || can_not_compile_call_site(orig_callee, klass)) { 429 #ifndef PRODUCT 430 if (PrintOpto && (Verbose || WizardMode)) { 431 method()->print_name(); tty->print_cr(" can not compile call at bci %d to:", bci()); 432 orig_callee->print_name(); tty->cr(); 433 } 434 #endif 435 return; 436 } 437 assert(holder_klass->is_loaded(), ""); 438 //assert((bc_callee->is_static() || is_invokedynamic) == !has_receiver , "must match bc"); // XXX invokehandle (cur_bc_raw) 439 // Note: this takes into account invokeinterface of methods declared in java/lang/Object, 440 // which should be invokevirtuals but according to the VM spec may be invokeinterfaces 441 assert(holder_klass->is_interface() || holder_klass->super() == NULL || (bc() != Bytecodes::_invokeinterface), "must match bc"); 442 // Note: In the absence of miranda methods, an abstract class K can perform 443 // an invokevirtual directly on an interface method I.m if K implements I. 444 445 // orig_callee is the resolved callee which's signature includes the 446 // appendix argument. 447 const int nargs = orig_callee->arg_size(); 448 const bool is_signature_polymorphic = MethodHandles::is_signature_polymorphic(orig_callee->intrinsic_id()); 449 450 // Push appendix argument (MethodType, CallSite, etc.), if one. 451 if (iter().has_appendix()) { 452 ciObject* appendix_arg = iter().get_appendix(); 453 const TypeOopPtr* appendix_arg_type = TypeOopPtr::make_from_constant(appendix_arg); 454 Node* appendix_arg_node = _gvn.makecon(appendix_arg_type); 455 push(appendix_arg_node); 456 } 457 458 // --------------------- 459 // Does Class Hierarchy Analysis reveal only a single target of a v-call? 460 // Then we may inline or make a static call, but become dependent on there being only 1 target. 461 // Does the call-site type profile reveal only one receiver? 462 // Then we may introduce a run-time check and inline on the path where it succeeds. 463 // The other path may uncommon_trap, check for another receiver, or do a v-call. 464 465 // Try to get the most accurate receiver type 466 ciMethod* callee = orig_callee; 467 int vtable_index = Method::invalid_vtable_index; 468 bool call_does_dispatch = false; 469 470 // Speculative type of the receiver if any 471 ciKlass* speculative_receiver_type = NULL; 472 if (is_virtual_or_interface) { 473 Node* receiver_node = stack(sp() - nargs); 474 const TypeOopPtr* receiver_type = _gvn.type(receiver_node)->isa_oopptr(); 475 // call_does_dispatch and vtable_index are out-parameters. They might be changed. 476 // For arrays, klass below is Object. When vtable calls are used, 477 // resolving the call with Object would allow an illegal call to 478 // finalize() on an array. We use holder instead: illegal calls to 479 // finalize() won't be compiled as vtable calls (IC call 480 // resolution will catch the illegal call) and the few legal calls 481 // on array types won't be either. 482 callee = C->optimize_virtual_call(method(), bci(), klass, holder, orig_callee, 483 receiver_type, is_virtual, 484 call_does_dispatch, vtable_index); // out-parameters 485 speculative_receiver_type = receiver_type != NULL ? receiver_type->speculative_type() : NULL; 486 } 487 488 // Note: It's OK to try to inline a virtual call. 489 // The call generator will not attempt to inline a polymorphic call 490 // unless it knows how to optimize the receiver dispatch. 491 bool try_inline = (C->do_inlining() || InlineAccessors); 492 493 // --------------------- 494 dec_sp(nargs); // Temporarily pop args for JVM state of call 495 JVMState* jvms = sync_jvms(); 496 497 // --------------------- 498 // Decide call tactic. 499 // This call checks with CHA, the interpreter profile, intrinsics table, etc. 500 // It decides whether inlining is desirable or not. 501 CallGenerator* cg = C->call_generator(callee, vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type); 502 503 // NOTE: Don't use orig_callee and callee after this point! Use cg->method() instead. 504 orig_callee = callee = NULL; 505 506 // --------------------- 507 // Round double arguments before call 508 round_double_arguments(cg->method()); 509 510 // Feed profiling data for arguments to the type system so it can 511 // propagate it as speculative types 512 record_profiled_arguments_for_speculation(cg->method(), bc()); 513 514 #ifndef PRODUCT 515 // bump global counters for calls 516 count_compiled_calls(/*at_method_entry*/ false, cg->is_inline()); 517 518 // Record first part of parsing work for this call 519 parse_histogram()->record_change(); 520 #endif // not PRODUCT 521 522 assert(jvms == this->jvms(), "still operating on the right JVMS"); 523 assert(jvms_in_sync(), "jvms must carry full info into CG"); 524 525 // save across call, for a subsequent cast_not_null. 526 Node* receiver = has_receiver ? argument(0) : NULL; 527 528 // The extra CheckCastPP for speculative types mess with PhaseStringOpts 529 if (receiver != NULL && !call_does_dispatch && !cg->is_string_late_inline()) { 530 // Feed profiling data for a single receiver to the type system so 531 // it can propagate it as a speculative type 532 receiver = record_profiled_receiver_for_speculation(receiver); 533 } 534 535 // Bump method data counters (We profile *before* the call is made 536 // because exceptions don't return to the call site.) 537 profile_call(receiver); 538 539 JVMState* new_jvms = cg->generate(jvms); 540 if (new_jvms == NULL) { 541 // When inlining attempt fails (e.g., too many arguments), 542 // it may contaminate the current compile state, making it 543 // impossible to pull back and try again. Once we call 544 // cg->generate(), we are committed. If it fails, the whole 545 // compilation task is compromised. 546 if (failing()) return; 547 548 // This can happen if a library intrinsic is available, but refuses 549 // the call site, perhaps because it did not match a pattern the 550 // intrinsic was expecting to optimize. Should always be possible to 551 // get a normal java call that may inline in that case 552 cg = C->call_generator(cg->method(), vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type, /* allow_intrinsics= */ false); 553 new_jvms = cg->generate(jvms); 554 if (new_jvms == NULL) { 555 guarantee(failing(), "call failed to generate: calls should work"); 556 return; 557 } 558 } 559 560 if (cg->is_inline()) { 561 // Accumulate has_loops estimate 562 C->set_has_loops(C->has_loops() || cg->method()->has_loops()); 563 C->env()->notice_inlined_method(cg->method()); 564 } 565 566 // Reset parser state from [new_]jvms, which now carries results of the call. 567 // Return value (if any) is already pushed on the stack by the cg. 568 add_exception_states_from(new_jvms); 569 if (new_jvms->map()->control() == top()) { 570 stop_and_kill_map(); 571 } else { 572 assert(new_jvms->same_calls_as(jvms), "method/bci left unchanged"); 573 set_jvms(new_jvms); 574 } 575 576 if (!stopped()) { 577 // This was some sort of virtual call, which did a null check for us. 578 // Now we can assert receiver-not-null, on the normal return path. 579 if (receiver != NULL && cg->is_virtual()) { 580 Node* cast = cast_not_null(receiver); 581 // %%% assert(receiver == cast, "should already have cast the receiver"); 582 } 583 584 // Round double result after a call from strict to non-strict code 585 round_double_result(cg->method()); 586 587 ciType* rtype = cg->method()->return_type(); 588 ciType* ctype = declared_signature->return_type(); 589 590 if (Bytecodes::has_optional_appendix(iter().cur_bc_raw()) || is_signature_polymorphic) { 591 // Be careful here with return types. 592 if (ctype != rtype) { 593 BasicType rt = rtype->basic_type(); 594 BasicType ct = ctype->basic_type(); 595 if (ct == T_VOID) { 596 // It's OK for a method to return a value that is discarded. 597 // The discarding does not require any special action from the caller. 598 // The Java code knows this, at VerifyType.isNullConversion. 599 pop_node(rt); // whatever it was, pop it 600 } else if (rt == T_INT || is_subword_type(rt)) { 601 // Nothing. These cases are handled in lambda form bytecode. 602 assert(ct == T_INT || is_subword_type(ct), err_msg_res("must match: rt=%s, ct=%s", type2name(rt), type2name(ct))); 603 } else if (rt == T_OBJECT || rt == T_ARRAY) { 604 assert(ct == T_OBJECT || ct == T_ARRAY, err_msg_res("rt=%s, ct=%s", type2name(rt), type2name(ct))); 605 if (ctype->is_loaded()) { 606 const TypeOopPtr* arg_type = TypeOopPtr::make_from_klass(rtype->as_klass()); 607 const Type* sig_type = TypeOopPtr::make_from_klass(ctype->as_klass()); 608 if (arg_type != NULL && !arg_type->higher_equal(sig_type)) { 609 Node* retnode = pop(); 610 Node* cast_obj = _gvn.transform(new CheckCastPPNode(control(), retnode, sig_type)); 611 push(cast_obj); 612 } 613 } 614 } else { 615 assert(rt == ct, err_msg_res("unexpected mismatch: rt=%s, ct=%s", type2name(rt), type2name(ct))); 616 // push a zero; it's better than getting an oop/int mismatch 617 pop_node(rt); 618 Node* retnode = zerocon(ct); 619 push_node(ct, retnode); 620 } 621 // Now that the value is well-behaved, continue with the call-site type. 622 rtype = ctype; 623 } 624 } else { 625 // Symbolic resolution enforces the types to be the same. 626 // NOTE: We must relax the assert for unloaded types because two 627 // different ciType instances of the same unloaded class type 628 // can appear to be "loaded" by different loaders (depending on 629 // the accessing class). 630 assert(!rtype->is_loaded() || !ctype->is_loaded() || rtype == ctype, 631 err_msg_res("mismatched return types: rtype=%s, ctype=%s", rtype->name(), ctype->name())); 632 } 633 634 // If the return type of the method is not loaded, assert that the 635 // value we got is a null. Otherwise, we need to recompile. 636 if (!rtype->is_loaded()) { 637 #ifndef PRODUCT 638 if (PrintOpto && (Verbose || WizardMode)) { 639 method()->print_name(); tty->print_cr(" asserting nullness of result at bci: %d", bci()); 640 cg->method()->print_name(); tty->cr(); 641 } 642 #endif 643 if (C->log() != NULL) { 644 C->log()->elem("assert_null reason='return' klass='%d'", 645 C->log()->identify(rtype)); 646 } 647 // If there is going to be a trap, put it at the next bytecode: 648 set_bci(iter().next_bci()); 649 null_assert(peek()); 650 set_bci(iter().cur_bci()); // put it back 651 } 652 BasicType ct = ctype->basic_type(); 653 if (ct == T_OBJECT || ct == T_ARRAY) { 654 record_profiled_return_for_speculation(); 655 } 656 } 657 658 // Restart record of parsing work after possible inlining of call 659 #ifndef PRODUCT 660 parse_histogram()->set_initial_state(bc()); 661 #endif 662 } 663 664 //---------------------------catch_call_exceptions----------------------------- 665 // Put a Catch and CatchProj nodes behind a just-created call. 666 // Send their caught exceptions to the proper handler. 667 // This may be used after a call to the rethrow VM stub, 668 // when it is needed to process unloaded exception classes. 669 void Parse::catch_call_exceptions(ciExceptionHandlerStream& handlers) { 670 // Exceptions are delivered through this channel: 671 Node* i_o = this->i_o(); 672 673 // Add a CatchNode. 674 GrowableArray<int>* bcis = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, -1); 675 GrowableArray<const Type*>* extypes = new (C->node_arena()) GrowableArray<const Type*>(C->node_arena(), 8, 0, NULL); 676 GrowableArray<int>* saw_unloaded = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, 0); 677 678 for (; !handlers.is_done(); handlers.next()) { 679 ciExceptionHandler* h = handlers.handler(); 680 int h_bci = h->handler_bci(); 681 ciInstanceKlass* h_klass = h->is_catch_all() ? env()->Throwable_klass() : h->catch_klass(); 682 // Do not introduce unloaded exception types into the graph: 683 if (!h_klass->is_loaded()) { 684 if (saw_unloaded->contains(h_bci)) { 685 /* We've already seen an unloaded exception with h_bci, 686 so don't duplicate. Duplication will cause the CatchNode to be 687 unnecessarily large. See 4713716. */ 688 continue; 689 } else { 690 saw_unloaded->append(h_bci); 691 } 692 } 693 const Type* h_extype = TypeOopPtr::make_from_klass(h_klass); 694 // (We use make_from_klass because it respects UseUniqueSubclasses.) 695 h_extype = h_extype->join(TypeInstPtr::NOTNULL); 696 assert(!h_extype->empty(), "sanity"); 697 // Note: It's OK if the BCIs repeat themselves. 698 bcis->append(h_bci); 699 extypes->append(h_extype); 700 } 701 702 int len = bcis->length(); 703 CatchNode *cn = new CatchNode(control(), i_o, len+1); 704 Node *catch_ = _gvn.transform(cn); 705 706 // now branch with the exception state to each of the (potential) 707 // handlers 708 for(int i=0; i < len; i++) { 709 // Setup JVM state to enter the handler. 710 PreserveJVMState pjvms(this); 711 // Locals are just copied from before the call. 712 // Get control from the CatchNode. 713 int handler_bci = bcis->at(i); 714 Node* ctrl = _gvn.transform( new CatchProjNode(catch_, i+1,handler_bci)); 715 // This handler cannot happen? 716 if (ctrl == top()) continue; 717 set_control(ctrl); 718 719 // Create exception oop 720 const TypeInstPtr* extype = extypes->at(i)->is_instptr(); 721 Node *ex_oop = _gvn.transform(new CreateExNode(extypes->at(i), ctrl, i_o)); 722 723 // Handle unloaded exception classes. 724 if (saw_unloaded->contains(handler_bci)) { 725 // An unloaded exception type is coming here. Do an uncommon trap. 726 #ifndef PRODUCT 727 // We do not expect the same handler bci to take both cold unloaded 728 // and hot loaded exceptions. But, watch for it. 729 if ((Verbose || WizardMode) && extype->is_loaded()) { 730 tty->print("Warning: Handler @%d takes mixed loaded/unloaded exceptions in ", bci()); 731 method()->print_name(); tty->cr(); 732 } else if (PrintOpto && (Verbose || WizardMode)) { 733 tty->print("Bailing out on unloaded exception type "); 734 extype->klass()->print_name(); 735 tty->print(" at bci:%d in ", bci()); 736 method()->print_name(); tty->cr(); 737 } 738 #endif 739 // Emit an uncommon trap instead of processing the block. 740 set_bci(handler_bci); 741 push_ex_oop(ex_oop); 742 uncommon_trap(Deoptimization::Reason_unloaded, 743 Deoptimization::Action_reinterpret, 744 extype->klass(), "!loaded exception"); 745 set_bci(iter().cur_bci()); // put it back 746 continue; 747 } 748 749 // go to the exception handler 750 if (handler_bci < 0) { // merge with corresponding rethrow node 751 throw_to_exit(make_exception_state(ex_oop)); 752 } else { // Else jump to corresponding handle 753 push_ex_oop(ex_oop); // Clear stack and push just the oop. 754 merge_exception(handler_bci); 755 } 756 } 757 758 // The first CatchProj is for the normal return. 759 // (Note: If this is a call to rethrow_Java, this node goes dead.) 760 set_control(_gvn.transform( new CatchProjNode(catch_, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci))); 761 } 762 763 764 //----------------------------catch_inline_exceptions-------------------------- 765 // Handle all exceptions thrown by an inlined method or individual bytecode. 766 // Common case 1: we have no handler, so all exceptions merge right into 767 // the rethrow case. 768 // Case 2: we have some handlers, with loaded exception klasses that have 769 // no subklasses. We do a Deutsch-Shiffman style type-check on the incoming 770 // exception oop and branch to the handler directly. 771 // Case 3: We have some handlers with subklasses or are not loaded at 772 // compile-time. We have to call the runtime to resolve the exception. 773 // So we insert a RethrowCall and all the logic that goes with it. 774 void Parse::catch_inline_exceptions(SafePointNode* ex_map) { 775 // Caller is responsible for saving away the map for normal control flow! 776 assert(stopped(), "call set_map(NULL) first"); 777 assert(method()->has_exception_handlers(), "don't come here w/o work to do"); 778 779 Node* ex_node = saved_ex_oop(ex_map); 780 if (ex_node == top()) { 781 // No action needed. 782 return; 783 } 784 const TypeInstPtr* ex_type = _gvn.type(ex_node)->isa_instptr(); 785 NOT_PRODUCT(if (ex_type==NULL) tty->print_cr("*** Exception not InstPtr")); 786 if (ex_type == NULL) 787 ex_type = TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr(); 788 789 // determine potential exception handlers 790 ciExceptionHandlerStream handlers(method(), bci(), 791 ex_type->klass()->as_instance_klass(), 792 ex_type->klass_is_exact()); 793 794 // Start executing from the given throw state. (Keep its stack, for now.) 795 // Get the exception oop as known at compile time. 796 ex_node = use_exception_state(ex_map); 797 798 // Get the exception oop klass from its header 799 Node* ex_klass_node = NULL; 800 if (has_ex_handler() && !ex_type->klass_is_exact()) { 801 Node* p = basic_plus_adr( ex_node, ex_node, oopDesc::klass_offset_in_bytes()); 802 ex_klass_node = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT)); 803 804 // Compute the exception klass a little more cleverly. 805 // Obvious solution is to simple do a LoadKlass from the 'ex_node'. 806 // However, if the ex_node is a PhiNode, I'm going to do a LoadKlass for 807 // each arm of the Phi. If I know something clever about the exceptions 808 // I'm loading the class from, I can replace the LoadKlass with the 809 // klass constant for the exception oop. 810 if (ex_node->is_Phi()) { 811 ex_klass_node = new PhiNode(ex_node->in(0), TypeKlassPtr::OBJECT); 812 for (uint i = 1; i < ex_node->req(); i++) { 813 Node* ex_in = ex_node->in(i); 814 if (ex_in == top() || ex_in == NULL) { 815 // This path was not taken. 816 ex_klass_node->init_req(i, top()); 817 continue; 818 } 819 Node* p = basic_plus_adr(ex_in, ex_in, oopDesc::klass_offset_in_bytes()); 820 Node* k = _gvn.transform( LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT)); 821 ex_klass_node->init_req( i, k ); 822 } 823 _gvn.set_type(ex_klass_node, TypeKlassPtr::OBJECT); 824 825 } 826 } 827 828 // Scan the exception table for applicable handlers. 829 // If none, we can call rethrow() and be done! 830 // If precise (loaded with no subklasses), insert a D.S. style 831 // pointer compare to the correct handler and loop back. 832 // If imprecise, switch to the Rethrow VM-call style handling. 833 834 int remaining = handlers.count_remaining(); 835 836 // iterate through all entries sequentially 837 for (;!handlers.is_done(); handlers.next()) { 838 ciExceptionHandler* handler = handlers.handler(); 839 840 if (handler->is_rethrow()) { 841 // If we fell off the end of the table without finding an imprecise 842 // exception klass (and without finding a generic handler) then we 843 // know this exception is not handled in this method. We just rethrow 844 // the exception into the caller. 845 throw_to_exit(make_exception_state(ex_node)); 846 return; 847 } 848 849 // exception handler bci range covers throw_bci => investigate further 850 int handler_bci = handler->handler_bci(); 851 852 if (remaining == 1) { 853 push_ex_oop(ex_node); // Push exception oop for handler 854 #ifndef PRODUCT 855 if (PrintOpto && WizardMode) { 856 tty->print_cr(" Catching every inline exception bci:%d -> handler_bci:%d", bci(), handler_bci); 857 } 858 #endif 859 merge_exception(handler_bci); // jump to handler 860 return; // No more handling to be done here! 861 } 862 863 // Get the handler's klass 864 ciInstanceKlass* klass = handler->catch_klass(); 865 866 if (!klass->is_loaded()) { // klass is not loaded? 867 // fall through into catch_call_exceptions which will emit a 868 // handler with an uncommon trap. 869 break; 870 } 871 872 if (klass->is_interface()) // should not happen, but... 873 break; // bail out 874 875 // Check the type of the exception against the catch type 876 const TypeKlassPtr *tk = TypeKlassPtr::make(klass); 877 Node* con = _gvn.makecon(tk); 878 Node* not_subtype_ctrl = gen_subtype_check(ex_klass_node, con); 879 if (!stopped()) { 880 PreserveJVMState pjvms(this); 881 const TypeInstPtr* tinst = TypeOopPtr::make_from_klass_unique(klass)->cast_to_ptr_type(TypePtr::NotNull)->is_instptr(); 882 assert(klass->has_subklass() || tinst->klass_is_exact(), "lost exactness"); 883 Node* ex_oop = _gvn.transform(new CheckCastPPNode(control(), ex_node, tinst)); 884 push_ex_oop(ex_oop); // Push exception oop for handler 885 #ifndef PRODUCT 886 if (PrintOpto && WizardMode) { 887 tty->print(" Catching inline exception bci:%d -> handler_bci:%d -- ", bci(), handler_bci); 888 klass->print_name(); 889 tty->cr(); 890 } 891 #endif 892 merge_exception(handler_bci); 893 } 894 set_control(not_subtype_ctrl); 895 896 // Come here if exception does not match handler. 897 // Carry on with more handler checks. 898 --remaining; 899 } 900 901 assert(!stopped(), "you should return if you finish the chain"); 902 903 // Oops, need to call into the VM to resolve the klasses at runtime. 904 // Note: This call must not deoptimize, since it is not a real at this bci! 905 kill_dead_locals(); 906 907 make_runtime_call(RC_NO_LEAF | RC_MUST_THROW, 908 OptoRuntime::rethrow_Type(), 909 OptoRuntime::rethrow_stub(), 910 NULL, NULL, 911 ex_node); 912 913 // Rethrow is a pure call, no side effects, only a result. 914 // The result cannot be allocated, so we use I_O 915 916 // Catch exceptions from the rethrow 917 catch_call_exceptions(handlers); 918 } 919 920 921 // (Note: Moved add_debug_info into GraphKit::add_safepoint_edges.) 922 923 924 #ifndef PRODUCT 925 void Parse::count_compiled_calls(bool at_method_entry, bool is_inline) { 926 if( CountCompiledCalls ) { 927 if( at_method_entry ) { 928 // bump invocation counter if top method (for statistics) 929 if (CountCompiledCalls && depth() == 1) { 930 const TypePtr* addr_type = TypeMetadataPtr::make(method()); 931 Node* adr1 = makecon(addr_type); 932 Node* adr2 = basic_plus_adr(adr1, adr1, in_bytes(Method::compiled_invocation_counter_offset())); 933 increment_counter(adr2); 934 } 935 } else if (is_inline) { 936 switch (bc()) { 937 case Bytecodes::_invokevirtual: increment_counter(SharedRuntime::nof_inlined_calls_addr()); break; 938 case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_inlined_interface_calls_addr()); break; 939 case Bytecodes::_invokestatic: 940 case Bytecodes::_invokedynamic: 941 case Bytecodes::_invokespecial: increment_counter(SharedRuntime::nof_inlined_static_calls_addr()); break; 942 default: fatal("unexpected call bytecode"); 943 } 944 } else { 945 switch (bc()) { 946 case Bytecodes::_invokevirtual: increment_counter(SharedRuntime::nof_normal_calls_addr()); break; 947 case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_interface_calls_addr()); break; 948 case Bytecodes::_invokestatic: 949 case Bytecodes::_invokedynamic: 950 case Bytecodes::_invokespecial: increment_counter(SharedRuntime::nof_static_calls_addr()); break; 951 default: fatal("unexpected call bytecode"); 952 } 953 } 954 } 955 } 956 #endif //PRODUCT 957 958 959 ciMethod* Compile::optimize_virtual_call(ciMethod* caller, int bci, ciInstanceKlass* klass, 960 ciKlass* holder, ciMethod* callee, 961 const TypeOopPtr* receiver_type, bool is_virtual, 962 bool& call_does_dispatch, int& vtable_index, 963 bool check_access) { 964 // Set default values for out-parameters. 965 call_does_dispatch = true; 966 vtable_index = Method::invalid_vtable_index; 967 968 // Choose call strategy. 969 ciMethod* optimized_virtual_method = optimize_inlining(caller, bci, klass, callee, 970 receiver_type, check_access); 971 972 // Have the call been sufficiently improved such that it is no longer a virtual? 973 if (optimized_virtual_method != NULL) { 974 callee = optimized_virtual_method; 975 call_does_dispatch = false; 976 } else if (!UseInlineCaches && is_virtual && callee->is_loaded()) { 977 // We can make a vtable call at this site 978 vtable_index = callee->resolve_vtable_index(caller->holder(), holder); 979 } 980 return callee; 981 } 982 983 // Identify possible target method and inlining style 984 ciMethod* Compile::optimize_inlining(ciMethod* caller, int bci, ciInstanceKlass* klass, 985 ciMethod* callee, const TypeOopPtr* receiver_type, 986 bool check_access) { 987 // only use for virtual or interface calls 988 989 // If it is obviously final, do not bother to call find_monomorphic_target, 990 // because the class hierarchy checks are not needed, and may fail due to 991 // incompletely loaded classes. Since we do our own class loading checks 992 // in this module, we may confidently bind to any method. 993 if (callee->can_be_statically_bound()) { 994 return callee; 995 } 996 997 // Attempt to improve the receiver 998 bool actual_receiver_is_exact = false; 999 ciInstanceKlass* actual_receiver = klass; 1000 if (receiver_type != NULL) { 1001 // Array methods are all inherited from Object, and are monomorphic. 1002 // finalize() call on array is not allowed. 1003 if (receiver_type->isa_aryptr() && 1004 callee->holder() == env()->Object_klass() && 1005 callee->name() != ciSymbol::finalize_method_name()) { 1006 return callee; 1007 } 1008 1009 // All other interesting cases are instance klasses. 1010 if (!receiver_type->isa_instptr()) { 1011 return NULL; 1012 } 1013 1014 ciInstanceKlass *ikl = receiver_type->klass()->as_instance_klass(); 1015 if (ikl->is_loaded() && ikl->is_initialized() && !ikl->is_interface() && 1016 (ikl == actual_receiver || ikl->is_subtype_of(actual_receiver))) { 1017 // ikl is a same or better type than the original actual_receiver, 1018 // e.g. static receiver from bytecodes. 1019 actual_receiver = ikl; 1020 // Is the actual_receiver exact? 1021 actual_receiver_is_exact = receiver_type->klass_is_exact(); 1022 } 1023 } 1024 1025 ciInstanceKlass* calling_klass = caller->holder(); 1026 ciMethod* cha_monomorphic_target = callee->find_monomorphic_target(calling_klass, klass, actual_receiver, check_access); 1027 if (cha_monomorphic_target != NULL) { 1028 assert(!cha_monomorphic_target->is_abstract(), ""); 1029 // Look at the method-receiver type. Does it add "too much information"? 1030 ciKlass* mr_klass = cha_monomorphic_target->holder(); 1031 const Type* mr_type = TypeInstPtr::make(TypePtr::BotPTR, mr_klass); 1032 if (receiver_type == NULL || !receiver_type->higher_equal(mr_type)) { 1033 // Calling this method would include an implicit cast to its holder. 1034 // %%% Not yet implemented. Would throw minor asserts at present. 1035 // %%% The most common wins are already gained by +UseUniqueSubclasses. 1036 // To fix, put the higher_equal check at the call of this routine, 1037 // and add a CheckCastPP to the receiver. 1038 if (TraceDependencies) { 1039 tty->print_cr("found unique CHA method, but could not cast up"); 1040 tty->print(" method = "); 1041 cha_monomorphic_target->print(); 1042 tty->cr(); 1043 } 1044 if (log() != NULL) { 1045 log()->elem("missed_CHA_opportunity klass='%d' method='%d'", 1046 log()->identify(klass), 1047 log()->identify(cha_monomorphic_target)); 1048 } 1049 cha_monomorphic_target = NULL; 1050 } 1051 } 1052 if (cha_monomorphic_target != NULL) { 1053 // Hardwiring a virtual. 1054 // If we inlined because CHA revealed only a single target method, 1055 // then we are dependent on that target method not getting overridden 1056 // by dynamic class loading. Be sure to test the "static" receiver 1057 // dest_method here, as opposed to the actual receiver, which may 1058 // falsely lead us to believe that the receiver is final or private. 1059 dependencies()->assert_unique_concrete_method(actual_receiver, cha_monomorphic_target); 1060 return cha_monomorphic_target; 1061 } 1062 1063 // If the type is exact, we can still bind the method w/o a vcall. 1064 // (This case comes after CHA so we can see how much extra work it does.) 1065 if (actual_receiver_is_exact) { 1066 // In case of evolution, there is a dependence on every inlined method, since each 1067 // such method can be changed when its class is redefined. 1068 ciMethod* exact_method = callee->resolve_invoke(calling_klass, actual_receiver); 1069 if (exact_method != NULL) { 1070 #ifndef PRODUCT 1071 if (PrintOpto) { 1072 tty->print(" Calling method via exact type @%d --- ", bci); 1073 exact_method->print_name(); 1074 tty->cr(); 1075 } 1076 #endif 1077 return exact_method; 1078 } 1079 } 1080 1081 return NULL; 1082 }