Tue, 25 Feb 2014 18:16:24 +0100
8031752: Failed speculative optimizations should be reattempted when root of compilation is different
Summary: support for speculative traps that keep track of the root of the compilation in which a trap occurs.
Reviewed-by: kvn, twisti
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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13 * accompanied this code).
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23 */
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/cfgnode.hpp"
35 #include "opto/mulnode.hpp"
36 #include "opto/parse.hpp"
37 #include "opto/rootnode.hpp"
38 #include "opto/runtime.hpp"
39 #include "opto/subnode.hpp"
40 #include "prims/nativeLookup.hpp"
41 #include "runtime/sharedRuntime.hpp"
43 void trace_type_profile(Compile* C, ciMethod *method, int depth, int bci, ciMethod *prof_method, ciKlass *prof_klass, int site_count, int receiver_count) {
44 if (TraceTypeProfile || C->print_inlining()) {
45 outputStream* out = tty;
46 if (!C->print_inlining()) {
47 if (NOT_PRODUCT(!PrintOpto &&) !PrintCompilation) {
48 method->print_short_name();
49 tty->cr();
50 }
51 CompileTask::print_inlining(prof_method, depth, bci);
52 } else {
53 out = C->print_inlining_stream();
54 }
55 CompileTask::print_inline_indent(depth, out);
56 out->print(" \\-> TypeProfile (%d/%d counts) = ", receiver_count, site_count);
57 stringStream ss;
58 prof_klass->name()->print_symbol_on(&ss);
59 out->print(ss.as_string());
60 out->cr();
61 }
62 }
64 CallGenerator* Compile::call_generator(ciMethod* callee, int vtable_index, bool call_does_dispatch,
65 JVMState* jvms, bool allow_inline,
66 float prof_factor, ciKlass* speculative_receiver_type,
67 bool allow_intrinsics, bool delayed_forbidden) {
68 ciMethod* caller = jvms->method();
69 int bci = jvms->bci();
70 Bytecodes::Code bytecode = caller->java_code_at_bci(bci);
71 guarantee(callee != NULL, "failed method resolution");
73 // Dtrace currently doesn't work unless all calls are vanilla
74 if (env()->dtrace_method_probes()) {
75 allow_inline = false;
76 }
78 // Note: When we get profiling during stage-1 compiles, we want to pull
79 // from more specific profile data which pertains to this inlining.
80 // Right now, ignore the information in jvms->caller(), and do method[bci].
81 ciCallProfile profile = caller->call_profile_at_bci(bci);
83 // See how many times this site has been invoked.
84 int site_count = profile.count();
85 int receiver_count = -1;
86 if (call_does_dispatch && UseTypeProfile && profile.has_receiver(0)) {
87 // Receivers in the profile structure are ordered by call counts
88 // so that the most called (major) receiver is profile.receiver(0).
89 receiver_count = profile.receiver_count(0);
90 }
92 CompileLog* log = this->log();
93 if (log != NULL) {
94 int rid = (receiver_count >= 0)? log->identify(profile.receiver(0)): -1;
95 int r2id = (rid != -1 && profile.has_receiver(1))? log->identify(profile.receiver(1)):-1;
96 log->begin_elem("call method='%d' count='%d' prof_factor='%g'",
97 log->identify(callee), site_count, prof_factor);
98 if (call_does_dispatch) log->print(" virtual='1'");
99 if (allow_inline) log->print(" inline='1'");
100 if (receiver_count >= 0) {
101 log->print(" receiver='%d' receiver_count='%d'", rid, receiver_count);
102 if (profile.has_receiver(1)) {
103 log->print(" receiver2='%d' receiver2_count='%d'", r2id, profile.receiver_count(1));
104 }
105 }
106 log->end_elem();
107 }
109 // Special case the handling of certain common, profitable library
110 // methods. If these methods are replaced with specialized code,
111 // then we return it as the inlined version of the call.
112 // We do this before the strict f.p. check below because the
113 // intrinsics handle strict f.p. correctly.
114 CallGenerator* cg_intrinsic = NULL;
115 if (allow_inline && allow_intrinsics) {
116 CallGenerator* cg = find_intrinsic(callee, call_does_dispatch);
117 if (cg != NULL) {
118 if (cg->is_predicted()) {
119 // Code without intrinsic but, hopefully, inlined.
120 CallGenerator* inline_cg = this->call_generator(callee,
121 vtable_index, call_does_dispatch, jvms, allow_inline, prof_factor, speculative_receiver_type, false);
122 if (inline_cg != NULL) {
123 cg = CallGenerator::for_predicted_intrinsic(cg, inline_cg);
124 }
125 }
127 // If intrinsic does the virtual dispatch, we try to use the type profile
128 // first, and hopefully inline it as the regular virtual call below.
129 // We will retry the intrinsic if nothing had claimed it afterwards.
130 if (cg->does_virtual_dispatch()) {
131 cg_intrinsic = cg;
132 cg = NULL;
133 } else {
134 return cg;
135 }
136 }
137 }
139 // Do method handle calls.
140 // NOTE: This must happen before normal inlining logic below since
141 // MethodHandle.invoke* are native methods which obviously don't
142 // have bytecodes and so normal inlining fails.
143 if (callee->is_method_handle_intrinsic()) {
144 CallGenerator* cg = CallGenerator::for_method_handle_call(jvms, caller, callee, delayed_forbidden);
145 assert(cg == NULL || !delayed_forbidden || !cg->is_late_inline() || cg->is_mh_late_inline(), "unexpected CallGenerator");
146 return cg;
147 }
149 // Do not inline strict fp into non-strict code, or the reverse
150 if (caller->is_strict() ^ callee->is_strict()) {
151 allow_inline = false;
152 }
154 // Attempt to inline...
155 if (allow_inline) {
156 // The profile data is only partly attributable to this caller,
157 // scale back the call site information.
158 float past_uses = jvms->method()->scale_count(site_count, prof_factor);
159 // This is the number of times we expect the call code to be used.
160 float expected_uses = past_uses;
162 // Try inlining a bytecoded method:
163 if (!call_does_dispatch) {
164 InlineTree* ilt = InlineTree::find_subtree_from_root(this->ilt(), jvms->caller(), jvms->method());
165 WarmCallInfo scratch_ci;
166 bool should_delay = false;
167 WarmCallInfo* ci = ilt->ok_to_inline(callee, jvms, profile, &scratch_ci, should_delay);
168 assert(ci != &scratch_ci, "do not let this pointer escape");
169 bool allow_inline = (ci != NULL && !ci->is_cold());
170 bool require_inline = (allow_inline && ci->is_hot());
172 if (allow_inline) {
173 CallGenerator* cg = CallGenerator::for_inline(callee, expected_uses);
175 if (require_inline && cg != NULL) {
176 // Delay the inlining of this method to give us the
177 // opportunity to perform some high level optimizations
178 // first.
179 if (should_delay_string_inlining(callee, jvms)) {
180 assert(!delayed_forbidden, "strange");
181 return CallGenerator::for_string_late_inline(callee, cg);
182 } else if (should_delay_boxing_inlining(callee, jvms)) {
183 assert(!delayed_forbidden, "strange");
184 return CallGenerator::for_boxing_late_inline(callee, cg);
185 } else if ((should_delay || AlwaysIncrementalInline) && !delayed_forbidden) {
186 return CallGenerator::for_late_inline(callee, cg);
187 }
188 }
189 if (cg == NULL || should_delay) {
190 // Fall through.
191 } else if (require_inline || !InlineWarmCalls) {
192 return cg;
193 } else {
194 CallGenerator* cold_cg = call_generator(callee, vtable_index, call_does_dispatch, jvms, false, prof_factor);
195 return CallGenerator::for_warm_call(ci, cold_cg, cg);
196 }
197 }
198 }
200 // Try using the type profile.
201 if (call_does_dispatch && site_count > 0 && receiver_count > 0) {
202 // The major receiver's count >= TypeProfileMajorReceiverPercent of site_count.
203 bool have_major_receiver = (100.*profile.receiver_prob(0) >= (float)TypeProfileMajorReceiverPercent);
204 ciMethod* receiver_method = NULL;
206 int morphism = profile.morphism();
207 if (speculative_receiver_type != NULL) {
208 // We have a speculative type, we should be able to resolve
209 // the call. We do that before looking at the profiling at
210 // this invoke because it may lead to bimorphic inlining which
211 // a speculative type should help us avoid.
212 receiver_method = callee->resolve_invoke(jvms->method()->holder(),
213 speculative_receiver_type);
214 if (receiver_method == NULL) {
215 speculative_receiver_type = NULL;
216 } else {
217 morphism = 1;
218 }
219 }
220 if (receiver_method == NULL &&
221 (have_major_receiver || morphism == 1 ||
222 (morphism == 2 && UseBimorphicInlining))) {
223 // receiver_method = profile.method();
224 // Profiles do not suggest methods now. Look it up in the major receiver.
225 receiver_method = callee->resolve_invoke(jvms->method()->holder(),
226 profile.receiver(0));
227 }
228 if (receiver_method != NULL) {
229 // The single majority receiver sufficiently outweighs the minority.
230 CallGenerator* hit_cg = this->call_generator(receiver_method,
231 vtable_index, !call_does_dispatch, jvms, allow_inline, prof_factor);
232 if (hit_cg != NULL) {
233 // Look up second receiver.
234 CallGenerator* next_hit_cg = NULL;
235 ciMethod* next_receiver_method = NULL;
236 if (morphism == 2 && UseBimorphicInlining) {
237 next_receiver_method = callee->resolve_invoke(jvms->method()->holder(),
238 profile.receiver(1));
239 if (next_receiver_method != NULL) {
240 next_hit_cg = this->call_generator(next_receiver_method,
241 vtable_index, !call_does_dispatch, jvms,
242 allow_inline, prof_factor);
243 if (next_hit_cg != NULL && !next_hit_cg->is_inline() &&
244 have_major_receiver && UseOnlyInlinedBimorphic) {
245 // Skip if we can't inline second receiver's method
246 next_hit_cg = NULL;
247 }
248 }
249 }
250 CallGenerator* miss_cg;
251 Deoptimization::DeoptReason reason = morphism == 2 ?
252 Deoptimization::Reason_bimorphic :
253 (speculative_receiver_type == NULL ? Deoptimization::Reason_class_check : Deoptimization::Reason_speculate_class_check);
254 if ((morphism == 1 || (morphism == 2 && next_hit_cg != NULL)) &&
255 !too_many_traps(jvms->method(), jvms->bci(), reason)
256 ) {
257 // Generate uncommon trap for class check failure path
258 // in case of monomorphic or bimorphic virtual call site.
259 miss_cg = CallGenerator::for_uncommon_trap(callee, reason,
260 Deoptimization::Action_maybe_recompile);
261 } else {
262 // Generate virtual call for class check failure path
263 // in case of polymorphic virtual call site.
264 miss_cg = CallGenerator::for_virtual_call(callee, vtable_index);
265 }
266 if (miss_cg != NULL) {
267 if (next_hit_cg != NULL) {
268 assert(speculative_receiver_type == NULL, "shouldn't end up here if we used speculation");
269 trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), next_receiver_method, profile.receiver(1), site_count, profile.receiver_count(1));
270 // We don't need to record dependency on a receiver here and below.
271 // Whenever we inline, the dependency is added by Parse::Parse().
272 miss_cg = CallGenerator::for_predicted_call(profile.receiver(1), miss_cg, next_hit_cg, PROB_MAX);
273 }
274 if (miss_cg != NULL) {
275 trace_type_profile(C, jvms->method(), jvms->depth() - 1, jvms->bci(), receiver_method, profile.receiver(0), site_count, receiver_count);
276 ciKlass* k = speculative_receiver_type != NULL ? speculative_receiver_type : profile.receiver(0);
277 float hit_prob = speculative_receiver_type != NULL ? 1.0 : profile.receiver_prob(0);
278 CallGenerator* cg = CallGenerator::for_predicted_call(k, miss_cg, hit_cg, hit_prob);
279 if (cg != NULL) return cg;
280 }
281 }
282 }
283 }
284 }
285 }
287 // Nothing claimed the intrinsic, we go with straight-forward inlining
288 // for already discovered intrinsic.
289 if (allow_inline && allow_intrinsics && cg_intrinsic != NULL) {
290 assert(cg_intrinsic->does_virtual_dispatch(), "sanity");
291 return cg_intrinsic;
292 }
294 // There was no special inlining tactic, or it bailed out.
295 // Use a more generic tactic, like a simple call.
296 if (call_does_dispatch) {
297 return CallGenerator::for_virtual_call(callee, vtable_index);
298 } else {
299 // Class Hierarchy Analysis or Type Profile reveals a unique target,
300 // or it is a static or special call.
301 return CallGenerator::for_direct_call(callee, should_delay_inlining(callee, jvms));
302 }
303 }
305 // Return true for methods that shouldn't be inlined early so that
306 // they are easier to analyze and optimize as intrinsics.
307 bool Compile::should_delay_string_inlining(ciMethod* call_method, JVMState* jvms) {
308 if (has_stringbuilder()) {
310 if ((call_method->holder() == C->env()->StringBuilder_klass() ||
311 call_method->holder() == C->env()->StringBuffer_klass()) &&
312 (jvms->method()->holder() == C->env()->StringBuilder_klass() ||
313 jvms->method()->holder() == C->env()->StringBuffer_klass())) {
314 // Delay SB calls only when called from non-SB code
315 return false;
316 }
318 switch (call_method->intrinsic_id()) {
319 case vmIntrinsics::_StringBuilder_void:
320 case vmIntrinsics::_StringBuilder_int:
321 case vmIntrinsics::_StringBuilder_String:
322 case vmIntrinsics::_StringBuilder_append_char:
323 case vmIntrinsics::_StringBuilder_append_int:
324 case vmIntrinsics::_StringBuilder_append_String:
325 case vmIntrinsics::_StringBuilder_toString:
326 case vmIntrinsics::_StringBuffer_void:
327 case vmIntrinsics::_StringBuffer_int:
328 case vmIntrinsics::_StringBuffer_String:
329 case vmIntrinsics::_StringBuffer_append_char:
330 case vmIntrinsics::_StringBuffer_append_int:
331 case vmIntrinsics::_StringBuffer_append_String:
332 case vmIntrinsics::_StringBuffer_toString:
333 case vmIntrinsics::_Integer_toString:
334 return true;
336 case vmIntrinsics::_String_String:
337 {
338 Node* receiver = jvms->map()->in(jvms->argoff() + 1);
339 if (receiver->is_Proj() && receiver->in(0)->is_CallStaticJava()) {
340 CallStaticJavaNode* csj = receiver->in(0)->as_CallStaticJava();
341 ciMethod* m = csj->method();
342 if (m != NULL &&
343 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
344 m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString))
345 // Delay String.<init>(new SB())
346 return true;
347 }
348 return false;
349 }
351 default:
352 return false;
353 }
354 }
355 return false;
356 }
358 bool Compile::should_delay_boxing_inlining(ciMethod* call_method, JVMState* jvms) {
359 if (eliminate_boxing() && call_method->is_boxing_method()) {
360 set_has_boxed_value(true);
361 return true;
362 }
363 return false;
364 }
366 // uncommon-trap call-sites where callee is unloaded, uninitialized or will not link
367 bool Parse::can_not_compile_call_site(ciMethod *dest_method, ciInstanceKlass* klass) {
368 // Additional inputs to consider...
369 // bc = bc()
370 // caller = method()
371 // iter().get_method_holder_index()
372 assert( dest_method->is_loaded(), "ciTypeFlow should not let us get here" );
373 // Interface classes can be loaded & linked and never get around to
374 // being initialized. Uncommon-trap for not-initialized static or
375 // v-calls. Let interface calls happen.
376 ciInstanceKlass* holder_klass = dest_method->holder();
377 if (!holder_klass->is_being_initialized() &&
378 !holder_klass->is_initialized() &&
379 !holder_klass->is_interface()) {
380 uncommon_trap(Deoptimization::Reason_uninitialized,
381 Deoptimization::Action_reinterpret,
382 holder_klass);
383 return true;
384 }
386 assert(dest_method->is_loaded(), "dest_method: typeflow responsibility");
387 return false;
388 }
391 //------------------------------do_call----------------------------------------
392 // Handle your basic call. Inline if we can & want to, else just setup call.
393 void Parse::do_call() {
394 // It's likely we are going to add debug info soon.
395 // Also, if we inline a guy who eventually needs debug info for this JVMS,
396 // our contribution to it is cleaned up right here.
397 kill_dead_locals();
399 // Set frequently used booleans
400 const bool is_virtual = bc() == Bytecodes::_invokevirtual;
401 const bool is_virtual_or_interface = is_virtual || bc() == Bytecodes::_invokeinterface;
402 const bool has_receiver = Bytecodes::has_receiver(bc());
404 // Find target being called
405 bool will_link;
406 ciSignature* declared_signature = NULL;
407 ciMethod* orig_callee = iter().get_method(will_link, &declared_signature); // callee in the bytecode
408 ciInstanceKlass* holder_klass = orig_callee->holder();
409 ciKlass* holder = iter().get_declared_method_holder();
410 ciInstanceKlass* klass = ciEnv::get_instance_klass_for_declared_method_holder(holder);
411 assert(declared_signature != NULL, "cannot be null");
413 // uncommon-trap when callee is unloaded, uninitialized or will not link
414 // bailout when too many arguments for register representation
415 if (!will_link || can_not_compile_call_site(orig_callee, klass)) {
416 #ifndef PRODUCT
417 if (PrintOpto && (Verbose || WizardMode)) {
418 method()->print_name(); tty->print_cr(" can not compile call at bci %d to:", bci());
419 orig_callee->print_name(); tty->cr();
420 }
421 #endif
422 return;
423 }
424 assert(holder_klass->is_loaded(), "");
425 //assert((bc_callee->is_static() || is_invokedynamic) == !has_receiver , "must match bc"); // XXX invokehandle (cur_bc_raw)
426 // Note: this takes into account invokeinterface of methods declared in java/lang/Object,
427 // which should be invokevirtuals but according to the VM spec may be invokeinterfaces
428 assert(holder_klass->is_interface() || holder_klass->super() == NULL || (bc() != Bytecodes::_invokeinterface), "must match bc");
429 // Note: In the absence of miranda methods, an abstract class K can perform
430 // an invokevirtual directly on an interface method I.m if K implements I.
432 // orig_callee is the resolved callee which's signature includes the
433 // appendix argument.
434 const int nargs = orig_callee->arg_size();
435 const bool is_signature_polymorphic = MethodHandles::is_signature_polymorphic(orig_callee->intrinsic_id());
437 // Push appendix argument (MethodType, CallSite, etc.), if one.
438 if (iter().has_appendix()) {
439 ciObject* appendix_arg = iter().get_appendix();
440 const TypeOopPtr* appendix_arg_type = TypeOopPtr::make_from_constant(appendix_arg);
441 Node* appendix_arg_node = _gvn.makecon(appendix_arg_type);
442 push(appendix_arg_node);
443 }
445 // ---------------------
446 // Does Class Hierarchy Analysis reveal only a single target of a v-call?
447 // Then we may inline or make a static call, but become dependent on there being only 1 target.
448 // Does the call-site type profile reveal only one receiver?
449 // Then we may introduce a run-time check and inline on the path where it succeeds.
450 // The other path may uncommon_trap, check for another receiver, or do a v-call.
452 // Try to get the most accurate receiver type
453 ciMethod* callee = orig_callee;
454 int vtable_index = Method::invalid_vtable_index;
455 bool call_does_dispatch = false;
457 // Speculative type of the receiver if any
458 ciKlass* speculative_receiver_type = NULL;
459 if (is_virtual_or_interface) {
460 Node* receiver_node = stack(sp() - nargs);
461 const TypeOopPtr* receiver_type = _gvn.type(receiver_node)->isa_oopptr();
462 // call_does_dispatch and vtable_index are out-parameters. They might be changed.
463 callee = C->optimize_virtual_call(method(), bci(), klass, orig_callee, receiver_type,
464 is_virtual,
465 call_does_dispatch, vtable_index); // out-parameters
466 speculative_receiver_type = receiver_type != NULL ? receiver_type->speculative_type() : NULL;
467 }
469 // Note: It's OK to try to inline a virtual call.
470 // The call generator will not attempt to inline a polymorphic call
471 // unless it knows how to optimize the receiver dispatch.
472 bool try_inline = (C->do_inlining() || InlineAccessors);
474 // ---------------------
475 dec_sp(nargs); // Temporarily pop args for JVM state of call
476 JVMState* jvms = sync_jvms();
478 // ---------------------
479 // Decide call tactic.
480 // This call checks with CHA, the interpreter profile, intrinsics table, etc.
481 // It decides whether inlining is desirable or not.
482 CallGenerator* cg = C->call_generator(callee, vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type);
484 // NOTE: Don't use orig_callee and callee after this point! Use cg->method() instead.
485 orig_callee = callee = NULL;
487 // ---------------------
488 // Round double arguments before call
489 round_double_arguments(cg->method());
491 // Feed profiling data for arguments to the type system so it can
492 // propagate it as speculative types
493 record_profiled_arguments_for_speculation(cg->method(), bc());
495 #ifndef PRODUCT
496 // bump global counters for calls
497 count_compiled_calls(/*at_method_entry*/ false, cg->is_inline());
499 // Record first part of parsing work for this call
500 parse_histogram()->record_change();
501 #endif // not PRODUCT
503 assert(jvms == this->jvms(), "still operating on the right JVMS");
504 assert(jvms_in_sync(), "jvms must carry full info into CG");
506 // save across call, for a subsequent cast_not_null.
507 Node* receiver = has_receiver ? argument(0) : NULL;
509 // The extra CheckCastPP for speculative types mess with PhaseStringOpts
510 if (receiver != NULL && !call_does_dispatch && !cg->is_string_late_inline()) {
511 // Feed profiling data for a single receiver to the type system so
512 // it can propagate it as a speculative type
513 receiver = record_profiled_receiver_for_speculation(receiver);
514 }
516 // Bump method data counters (We profile *before* the call is made
517 // because exceptions don't return to the call site.)
518 profile_call(receiver);
520 JVMState* new_jvms = cg->generate(jvms, this);
521 if (new_jvms == NULL) {
522 // When inlining attempt fails (e.g., too many arguments),
523 // it may contaminate the current compile state, making it
524 // impossible to pull back and try again. Once we call
525 // cg->generate(), we are committed. If it fails, the whole
526 // compilation task is compromised.
527 if (failing()) return;
529 // This can happen if a library intrinsic is available, but refuses
530 // the call site, perhaps because it did not match a pattern the
531 // intrinsic was expecting to optimize. Should always be possible to
532 // get a normal java call that may inline in that case
533 cg = C->call_generator(cg->method(), vtable_index, call_does_dispatch, jvms, try_inline, prof_factor(), speculative_receiver_type, /* allow_intrinsics= */ false);
534 if ((new_jvms = cg->generate(jvms, this)) == NULL) {
535 guarantee(failing(), "call failed to generate: calls should work");
536 return;
537 }
538 }
540 if (cg->is_inline()) {
541 // Accumulate has_loops estimate
542 C->set_has_loops(C->has_loops() || cg->method()->has_loops());
543 C->env()->notice_inlined_method(cg->method());
544 }
546 // Reset parser state from [new_]jvms, which now carries results of the call.
547 // Return value (if any) is already pushed on the stack by the cg.
548 add_exception_states_from(new_jvms);
549 if (new_jvms->map()->control() == top()) {
550 stop_and_kill_map();
551 } else {
552 assert(new_jvms->same_calls_as(jvms), "method/bci left unchanged");
553 set_jvms(new_jvms);
554 }
556 if (!stopped()) {
557 // This was some sort of virtual call, which did a null check for us.
558 // Now we can assert receiver-not-null, on the normal return path.
559 if (receiver != NULL && cg->is_virtual()) {
560 Node* cast = cast_not_null(receiver);
561 // %%% assert(receiver == cast, "should already have cast the receiver");
562 }
564 // Round double result after a call from strict to non-strict code
565 round_double_result(cg->method());
567 ciType* rtype = cg->method()->return_type();
568 ciType* ctype = declared_signature->return_type();
570 if (Bytecodes::has_optional_appendix(iter().cur_bc_raw()) || is_signature_polymorphic) {
571 // Be careful here with return types.
572 if (ctype != rtype) {
573 BasicType rt = rtype->basic_type();
574 BasicType ct = ctype->basic_type();
575 if (ct == T_VOID) {
576 // It's OK for a method to return a value that is discarded.
577 // The discarding does not require any special action from the caller.
578 // The Java code knows this, at VerifyType.isNullConversion.
579 pop_node(rt); // whatever it was, pop it
580 } else if (rt == T_INT || is_subword_type(rt)) {
581 // Nothing. These cases are handled in lambda form bytecode.
582 assert(ct == T_INT || is_subword_type(ct), err_msg_res("must match: rt=%s, ct=%s", type2name(rt), type2name(ct)));
583 } else if (rt == T_OBJECT || rt == T_ARRAY) {
584 assert(ct == T_OBJECT || ct == T_ARRAY, err_msg_res("rt=%s, ct=%s", type2name(rt), type2name(ct)));
585 if (ctype->is_loaded()) {
586 const TypeOopPtr* arg_type = TypeOopPtr::make_from_klass(rtype->as_klass());
587 const Type* sig_type = TypeOopPtr::make_from_klass(ctype->as_klass());
588 if (arg_type != NULL && !arg_type->higher_equal(sig_type)) {
589 Node* retnode = pop();
590 Node* cast_obj = _gvn.transform(new (C) CheckCastPPNode(control(), retnode, sig_type));
591 push(cast_obj);
592 }
593 }
594 } else {
595 assert(rt == ct, err_msg_res("unexpected mismatch: rt=%s, ct=%s", type2name(rt), type2name(ct)));
596 // push a zero; it's better than getting an oop/int mismatch
597 pop_node(rt);
598 Node* retnode = zerocon(ct);
599 push_node(ct, retnode);
600 }
601 // Now that the value is well-behaved, continue with the call-site type.
602 rtype = ctype;
603 }
604 } else {
605 // Symbolic resolution enforces the types to be the same.
606 // NOTE: We must relax the assert for unloaded types because two
607 // different ciType instances of the same unloaded class type
608 // can appear to be "loaded" by different loaders (depending on
609 // the accessing class).
610 assert(!rtype->is_loaded() || !ctype->is_loaded() || rtype == ctype,
611 err_msg_res("mismatched return types: rtype=%s, ctype=%s", rtype->name(), ctype->name()));
612 }
614 // If the return type of the method is not loaded, assert that the
615 // value we got is a null. Otherwise, we need to recompile.
616 if (!rtype->is_loaded()) {
617 #ifndef PRODUCT
618 if (PrintOpto && (Verbose || WizardMode)) {
619 method()->print_name(); tty->print_cr(" asserting nullness of result at bci: %d", bci());
620 cg->method()->print_name(); tty->cr();
621 }
622 #endif
623 if (C->log() != NULL) {
624 C->log()->elem("assert_null reason='return' klass='%d'",
625 C->log()->identify(rtype));
626 }
627 // If there is going to be a trap, put it at the next bytecode:
628 set_bci(iter().next_bci());
629 null_assert(peek());
630 set_bci(iter().cur_bci()); // put it back
631 }
632 BasicType ct = ctype->basic_type();
633 if (ct == T_OBJECT || ct == T_ARRAY) {
634 ciKlass* better_type = method()->return_profiled_type(bci());
635 if (UseTypeSpeculation && better_type != NULL) {
636 // If profiling reports a single type for the return value,
637 // feed it to the type system so it can propagate it as a
638 // speculative type
639 record_profile_for_speculation(stack(sp()-1), better_type);
640 }
641 }
642 }
644 // Restart record of parsing work after possible inlining of call
645 #ifndef PRODUCT
646 parse_histogram()->set_initial_state(bc());
647 #endif
648 }
650 //---------------------------catch_call_exceptions-----------------------------
651 // Put a Catch and CatchProj nodes behind a just-created call.
652 // Send their caught exceptions to the proper handler.
653 // This may be used after a call to the rethrow VM stub,
654 // when it is needed to process unloaded exception classes.
655 void Parse::catch_call_exceptions(ciExceptionHandlerStream& handlers) {
656 // Exceptions are delivered through this channel:
657 Node* i_o = this->i_o();
659 // Add a CatchNode.
660 GrowableArray<int>* bcis = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, -1);
661 GrowableArray<const Type*>* extypes = new (C->node_arena()) GrowableArray<const Type*>(C->node_arena(), 8, 0, NULL);
662 GrowableArray<int>* saw_unloaded = new (C->node_arena()) GrowableArray<int>(C->node_arena(), 8, 0, 0);
664 for (; !handlers.is_done(); handlers.next()) {
665 ciExceptionHandler* h = handlers.handler();
666 int h_bci = h->handler_bci();
667 ciInstanceKlass* h_klass = h->is_catch_all() ? env()->Throwable_klass() : h->catch_klass();
668 // Do not introduce unloaded exception types into the graph:
669 if (!h_klass->is_loaded()) {
670 if (saw_unloaded->contains(h_bci)) {
671 /* We've already seen an unloaded exception with h_bci,
672 so don't duplicate. Duplication will cause the CatchNode to be
673 unnecessarily large. See 4713716. */
674 continue;
675 } else {
676 saw_unloaded->append(h_bci);
677 }
678 }
679 const Type* h_extype = TypeOopPtr::make_from_klass(h_klass);
680 // (We use make_from_klass because it respects UseUniqueSubclasses.)
681 h_extype = h_extype->join(TypeInstPtr::NOTNULL);
682 assert(!h_extype->empty(), "sanity");
683 // Note: It's OK if the BCIs repeat themselves.
684 bcis->append(h_bci);
685 extypes->append(h_extype);
686 }
688 int len = bcis->length();
689 CatchNode *cn = new (C) CatchNode(control(), i_o, len+1);
690 Node *catch_ = _gvn.transform(cn);
692 // now branch with the exception state to each of the (potential)
693 // handlers
694 for(int i=0; i < len; i++) {
695 // Setup JVM state to enter the handler.
696 PreserveJVMState pjvms(this);
697 // Locals are just copied from before the call.
698 // Get control from the CatchNode.
699 int handler_bci = bcis->at(i);
700 Node* ctrl = _gvn.transform( new (C) CatchProjNode(catch_, i+1,handler_bci));
701 // This handler cannot happen?
702 if (ctrl == top()) continue;
703 set_control(ctrl);
705 // Create exception oop
706 const TypeInstPtr* extype = extypes->at(i)->is_instptr();
707 Node *ex_oop = _gvn.transform(new (C) CreateExNode(extypes->at(i), ctrl, i_o));
709 // Handle unloaded exception classes.
710 if (saw_unloaded->contains(handler_bci)) {
711 // An unloaded exception type is coming here. Do an uncommon trap.
712 #ifndef PRODUCT
713 // We do not expect the same handler bci to take both cold unloaded
714 // and hot loaded exceptions. But, watch for it.
715 if ((Verbose || WizardMode) && extype->is_loaded()) {
716 tty->print("Warning: Handler @%d takes mixed loaded/unloaded exceptions in ", bci());
717 method()->print_name(); tty->cr();
718 } else if (PrintOpto && (Verbose || WizardMode)) {
719 tty->print("Bailing out on unloaded exception type ");
720 extype->klass()->print_name();
721 tty->print(" at bci:%d in ", bci());
722 method()->print_name(); tty->cr();
723 }
724 #endif
725 // Emit an uncommon trap instead of processing the block.
726 set_bci(handler_bci);
727 push_ex_oop(ex_oop);
728 uncommon_trap(Deoptimization::Reason_unloaded,
729 Deoptimization::Action_reinterpret,
730 extype->klass(), "!loaded exception");
731 set_bci(iter().cur_bci()); // put it back
732 continue;
733 }
735 // go to the exception handler
736 if (handler_bci < 0) { // merge with corresponding rethrow node
737 throw_to_exit(make_exception_state(ex_oop));
738 } else { // Else jump to corresponding handle
739 push_ex_oop(ex_oop); // Clear stack and push just the oop.
740 merge_exception(handler_bci);
741 }
742 }
744 // The first CatchProj is for the normal return.
745 // (Note: If this is a call to rethrow_Java, this node goes dead.)
746 set_control(_gvn.transform( new (C) CatchProjNode(catch_, CatchProjNode::fall_through_index, CatchProjNode::no_handler_bci)));
747 }
750 //----------------------------catch_inline_exceptions--------------------------
751 // Handle all exceptions thrown by an inlined method or individual bytecode.
752 // Common case 1: we have no handler, so all exceptions merge right into
753 // the rethrow case.
754 // Case 2: we have some handlers, with loaded exception klasses that have
755 // no subklasses. We do a Deutsch-Shiffman style type-check on the incoming
756 // exception oop and branch to the handler directly.
757 // Case 3: We have some handlers with subklasses or are not loaded at
758 // compile-time. We have to call the runtime to resolve the exception.
759 // So we insert a RethrowCall and all the logic that goes with it.
760 void Parse::catch_inline_exceptions(SafePointNode* ex_map) {
761 // Caller is responsible for saving away the map for normal control flow!
762 assert(stopped(), "call set_map(NULL) first");
763 assert(method()->has_exception_handlers(), "don't come here w/o work to do");
765 Node* ex_node = saved_ex_oop(ex_map);
766 if (ex_node == top()) {
767 // No action needed.
768 return;
769 }
770 const TypeInstPtr* ex_type = _gvn.type(ex_node)->isa_instptr();
771 NOT_PRODUCT(if (ex_type==NULL) tty->print_cr("*** Exception not InstPtr"));
772 if (ex_type == NULL)
773 ex_type = TypeOopPtr::make_from_klass(env()->Throwable_klass())->is_instptr();
775 // determine potential exception handlers
776 ciExceptionHandlerStream handlers(method(), bci(),
777 ex_type->klass()->as_instance_klass(),
778 ex_type->klass_is_exact());
780 // Start executing from the given throw state. (Keep its stack, for now.)
781 // Get the exception oop as known at compile time.
782 ex_node = use_exception_state(ex_map);
784 // Get the exception oop klass from its header
785 Node* ex_klass_node = NULL;
786 if (has_ex_handler() && !ex_type->klass_is_exact()) {
787 Node* p = basic_plus_adr( ex_node, ex_node, oopDesc::klass_offset_in_bytes());
788 ex_klass_node = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT) );
790 // Compute the exception klass a little more cleverly.
791 // Obvious solution is to simple do a LoadKlass from the 'ex_node'.
792 // However, if the ex_node is a PhiNode, I'm going to do a LoadKlass for
793 // each arm of the Phi. If I know something clever about the exceptions
794 // I'm loading the class from, I can replace the LoadKlass with the
795 // klass constant for the exception oop.
796 if( ex_node->is_Phi() ) {
797 ex_klass_node = new (C) PhiNode( ex_node->in(0), TypeKlassPtr::OBJECT );
798 for( uint i = 1; i < ex_node->req(); i++ ) {
799 Node* p = basic_plus_adr( ex_node->in(i), ex_node->in(i), oopDesc::klass_offset_in_bytes() );
800 Node* k = _gvn.transform( LoadKlassNode::make(_gvn, immutable_memory(), p, TypeInstPtr::KLASS, TypeKlassPtr::OBJECT) );
801 ex_klass_node->init_req( i, k );
802 }
803 _gvn.set_type(ex_klass_node, TypeKlassPtr::OBJECT);
805 }
806 }
808 // Scan the exception table for applicable handlers.
809 // If none, we can call rethrow() and be done!
810 // If precise (loaded with no subklasses), insert a D.S. style
811 // pointer compare to the correct handler and loop back.
812 // If imprecise, switch to the Rethrow VM-call style handling.
814 int remaining = handlers.count_remaining();
816 // iterate through all entries sequentially
817 for (;!handlers.is_done(); handlers.next()) {
818 ciExceptionHandler* handler = handlers.handler();
820 if (handler->is_rethrow()) {
821 // If we fell off the end of the table without finding an imprecise
822 // exception klass (and without finding a generic handler) then we
823 // know this exception is not handled in this method. We just rethrow
824 // the exception into the caller.
825 throw_to_exit(make_exception_state(ex_node));
826 return;
827 }
829 // exception handler bci range covers throw_bci => investigate further
830 int handler_bci = handler->handler_bci();
832 if (remaining == 1) {
833 push_ex_oop(ex_node); // Push exception oop for handler
834 #ifndef PRODUCT
835 if (PrintOpto && WizardMode) {
836 tty->print_cr(" Catching every inline exception bci:%d -> handler_bci:%d", bci(), handler_bci);
837 }
838 #endif
839 merge_exception(handler_bci); // jump to handler
840 return; // No more handling to be done here!
841 }
843 // Get the handler's klass
844 ciInstanceKlass* klass = handler->catch_klass();
846 if (!klass->is_loaded()) { // klass is not loaded?
847 // fall through into catch_call_exceptions which will emit a
848 // handler with an uncommon trap.
849 break;
850 }
852 if (klass->is_interface()) // should not happen, but...
853 break; // bail out
855 // Check the type of the exception against the catch type
856 const TypeKlassPtr *tk = TypeKlassPtr::make(klass);
857 Node* con = _gvn.makecon(tk);
858 Node* not_subtype_ctrl = gen_subtype_check(ex_klass_node, con);
859 if (!stopped()) {
860 PreserveJVMState pjvms(this);
861 const TypeInstPtr* tinst = TypeOopPtr::make_from_klass_unique(klass)->cast_to_ptr_type(TypePtr::NotNull)->is_instptr();
862 assert(klass->has_subklass() || tinst->klass_is_exact(), "lost exactness");
863 Node* ex_oop = _gvn.transform(new (C) CheckCastPPNode(control(), ex_node, tinst));
864 push_ex_oop(ex_oop); // Push exception oop for handler
865 #ifndef PRODUCT
866 if (PrintOpto && WizardMode) {
867 tty->print(" Catching inline exception bci:%d -> handler_bci:%d -- ", bci(), handler_bci);
868 klass->print_name();
869 tty->cr();
870 }
871 #endif
872 merge_exception(handler_bci);
873 }
874 set_control(not_subtype_ctrl);
876 // Come here if exception does not match handler.
877 // Carry on with more handler checks.
878 --remaining;
879 }
881 assert(!stopped(), "you should return if you finish the chain");
883 // Oops, need to call into the VM to resolve the klasses at runtime.
884 // Note: This call must not deoptimize, since it is not a real at this bci!
885 kill_dead_locals();
887 make_runtime_call(RC_NO_LEAF | RC_MUST_THROW,
888 OptoRuntime::rethrow_Type(),
889 OptoRuntime::rethrow_stub(),
890 NULL, NULL,
891 ex_node);
893 // Rethrow is a pure call, no side effects, only a result.
894 // The result cannot be allocated, so we use I_O
896 // Catch exceptions from the rethrow
897 catch_call_exceptions(handlers);
898 }
901 // (Note: Moved add_debug_info into GraphKit::add_safepoint_edges.)
904 #ifndef PRODUCT
905 void Parse::count_compiled_calls(bool at_method_entry, bool is_inline) {
906 if( CountCompiledCalls ) {
907 if( at_method_entry ) {
908 // bump invocation counter if top method (for statistics)
909 if (CountCompiledCalls && depth() == 1) {
910 const TypePtr* addr_type = TypeMetadataPtr::make(method());
911 Node* adr1 = makecon(addr_type);
912 Node* adr2 = basic_plus_adr(adr1, adr1, in_bytes(Method::compiled_invocation_counter_offset()));
913 increment_counter(adr2);
914 }
915 } else if (is_inline) {
916 switch (bc()) {
917 case Bytecodes::_invokevirtual: increment_counter(SharedRuntime::nof_inlined_calls_addr()); break;
918 case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_inlined_interface_calls_addr()); break;
919 case Bytecodes::_invokestatic:
920 case Bytecodes::_invokedynamic:
921 case Bytecodes::_invokespecial: increment_counter(SharedRuntime::nof_inlined_static_calls_addr()); break;
922 default: fatal("unexpected call bytecode");
923 }
924 } else {
925 switch (bc()) {
926 case Bytecodes::_invokevirtual: increment_counter(SharedRuntime::nof_normal_calls_addr()); break;
927 case Bytecodes::_invokeinterface: increment_counter(SharedRuntime::nof_interface_calls_addr()); break;
928 case Bytecodes::_invokestatic:
929 case Bytecodes::_invokedynamic:
930 case Bytecodes::_invokespecial: increment_counter(SharedRuntime::nof_static_calls_addr()); break;
931 default: fatal("unexpected call bytecode");
932 }
933 }
934 }
935 }
936 #endif //PRODUCT
939 ciMethod* Compile::optimize_virtual_call(ciMethod* caller, int bci, ciInstanceKlass* klass,
940 ciMethod* callee, const TypeOopPtr* receiver_type,
941 bool is_virtual,
942 bool& call_does_dispatch, int& vtable_index) {
943 // Set default values for out-parameters.
944 call_does_dispatch = true;
945 vtable_index = Method::invalid_vtable_index;
947 // Choose call strategy.
948 ciMethod* optimized_virtual_method = optimize_inlining(caller, bci, klass, callee, receiver_type);
950 // Have the call been sufficiently improved such that it is no longer a virtual?
951 if (optimized_virtual_method != NULL) {
952 callee = optimized_virtual_method;
953 call_does_dispatch = false;
954 } else if (!UseInlineCaches && is_virtual && callee->is_loaded()) {
955 // We can make a vtable call at this site
956 vtable_index = callee->resolve_vtable_index(caller->holder(), klass);
957 }
958 return callee;
959 }
961 // Identify possible target method and inlining style
962 ciMethod* Compile::optimize_inlining(ciMethod* caller, int bci, ciInstanceKlass* klass,
963 ciMethod* callee, const TypeOopPtr* receiver_type) {
964 // only use for virtual or interface calls
966 // If it is obviously final, do not bother to call find_monomorphic_target,
967 // because the class hierarchy checks are not needed, and may fail due to
968 // incompletely loaded classes. Since we do our own class loading checks
969 // in this module, we may confidently bind to any method.
970 if (callee->can_be_statically_bound()) {
971 return callee;
972 }
974 // Attempt to improve the receiver
975 bool actual_receiver_is_exact = false;
976 ciInstanceKlass* actual_receiver = klass;
977 if (receiver_type != NULL) {
978 // Array methods are all inherited from Object, and are monomorphic.
979 if (receiver_type->isa_aryptr() &&
980 callee->holder() == env()->Object_klass()) {
981 return callee;
982 }
984 // All other interesting cases are instance klasses.
985 if (!receiver_type->isa_instptr()) {
986 return NULL;
987 }
989 ciInstanceKlass *ikl = receiver_type->klass()->as_instance_klass();
990 if (ikl->is_loaded() && ikl->is_initialized() && !ikl->is_interface() &&
991 (ikl == actual_receiver || ikl->is_subtype_of(actual_receiver))) {
992 // ikl is a same or better type than the original actual_receiver,
993 // e.g. static receiver from bytecodes.
994 actual_receiver = ikl;
995 // Is the actual_receiver exact?
996 actual_receiver_is_exact = receiver_type->klass_is_exact();
997 }
998 }
1000 ciInstanceKlass* calling_klass = caller->holder();
1001 ciMethod* cha_monomorphic_target = callee->find_monomorphic_target(calling_klass, klass, actual_receiver);
1002 if (cha_monomorphic_target != NULL) {
1003 assert(!cha_monomorphic_target->is_abstract(), "");
1004 // Look at the method-receiver type. Does it add "too much information"?
1005 ciKlass* mr_klass = cha_monomorphic_target->holder();
1006 const Type* mr_type = TypeInstPtr::make(TypePtr::BotPTR, mr_klass);
1007 if (receiver_type == NULL || !receiver_type->higher_equal(mr_type)) {
1008 // Calling this method would include an implicit cast to its holder.
1009 // %%% Not yet implemented. Would throw minor asserts at present.
1010 // %%% The most common wins are already gained by +UseUniqueSubclasses.
1011 // To fix, put the higher_equal check at the call of this routine,
1012 // and add a CheckCastPP to the receiver.
1013 if (TraceDependencies) {
1014 tty->print_cr("found unique CHA method, but could not cast up");
1015 tty->print(" method = ");
1016 cha_monomorphic_target->print();
1017 tty->cr();
1018 }
1019 if (log() != NULL) {
1020 log()->elem("missed_CHA_opportunity klass='%d' method='%d'",
1021 log()->identify(klass),
1022 log()->identify(cha_monomorphic_target));
1023 }
1024 cha_monomorphic_target = NULL;
1025 }
1026 }
1027 if (cha_monomorphic_target != NULL) {
1028 // Hardwiring a virtual.
1029 // If we inlined because CHA revealed only a single target method,
1030 // then we are dependent on that target method not getting overridden
1031 // by dynamic class loading. Be sure to test the "static" receiver
1032 // dest_method here, as opposed to the actual receiver, which may
1033 // falsely lead us to believe that the receiver is final or private.
1034 dependencies()->assert_unique_concrete_method(actual_receiver, cha_monomorphic_target);
1035 return cha_monomorphic_target;
1036 }
1038 // If the type is exact, we can still bind the method w/o a vcall.
1039 // (This case comes after CHA so we can see how much extra work it does.)
1040 if (actual_receiver_is_exact) {
1041 // In case of evolution, there is a dependence on every inlined method, since each
1042 // such method can be changed when its class is redefined.
1043 ciMethod* exact_method = callee->resolve_invoke(calling_klass, actual_receiver);
1044 if (exact_method != NULL) {
1045 #ifndef PRODUCT
1046 if (PrintOpto) {
1047 tty->print(" Calling method via exact type @%d --- ", bci);
1048 exact_method->print_name();
1049 tty->cr();
1050 }
1051 #endif
1052 return exact_method;
1053 }
1054 }
1056 return NULL;
1057 }