1 /*
   2  * Copyright 1998-2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  *
  23  */
  24 
  25 #include "incls/_precompiled.incl"
  26 #include "incls/_bytecodeInfo.cpp.incl"
  27 
  28 //=============================================================================
  29 //------------------------------InlineTree-------------------------------------
  30 InlineTree::InlineTree( Compile* c, const InlineTree *caller_tree, ciMethod* callee, JVMState* caller_jvms, int caller_bci, float site_invoke_ratio )
  31 : C(c), _caller_jvms(caller_jvms),
  32   _caller_tree((InlineTree*)caller_tree),
  33   _method(callee), _site_invoke_ratio(site_invoke_ratio),
  34   _count_inline_bcs(method()->code_size()) {
  35   NOT_PRODUCT(_count_inlines = 0;)
  36   if (_caller_jvms != NULL) {
  37     // Keep a private copy of the caller_jvms:
  38     _caller_jvms = new (C) JVMState(caller_jvms->method(), caller_tree->caller_jvms());
  39     _caller_jvms->set_bci(caller_jvms->bci());
  40     assert(!caller_jvms->should_reexecute(), "there should be no reexecute bytecode with inlining");
  41   }
  42   assert(_caller_jvms->same_calls_as(caller_jvms), "consistent JVMS");
  43   assert((caller_tree == NULL ? 0 : caller_tree->inline_depth() + 1) == inline_depth(), "correct (redundant) depth parameter");
  44   assert(caller_bci == this->caller_bci(), "correct (redundant) bci parameter");
  45   if (UseOldInlining) {
  46     // Update hierarchical counts, count_inline_bcs() and count_inlines()
  47     InlineTree *caller = (InlineTree *)caller_tree;
  48     for( ; caller != NULL; caller = ((InlineTree *)(caller->caller_tree())) ) {
  49       caller->_count_inline_bcs += count_inline_bcs();
  50       NOT_PRODUCT(caller->_count_inlines++;)
  51     }
  52   }
  53 }
  54 
  55 InlineTree::InlineTree(Compile* c, ciMethod* callee_method, JVMState* caller_jvms, float site_invoke_ratio)
  56 : C(c), _caller_jvms(caller_jvms), _caller_tree(NULL),
  57   _method(callee_method), _site_invoke_ratio(site_invoke_ratio),
  58   _count_inline_bcs(method()->code_size()) {
  59   NOT_PRODUCT(_count_inlines = 0;)
  60   assert(!UseOldInlining, "do not use for old stuff");
  61 }
  62 
  63 
  64 
  65 static void print_indent(int depth) {
  66   tty->print("      ");
  67   for (int i = depth; i != 0; --i) tty->print("  ");
  68 }
  69 
  70 static bool is_init_with_ea(ciMethod* callee_method,
  71                             ciMethod* caller_method, Compile* C) {
  72   // True when EA is ON and a java constructor is called or
  73   // a super constructor is called from an inlined java constructor.
  74   return C->do_escape_analysis() && EliminateAllocations &&
  75          ( callee_method->is_initializer() ||
  76            (caller_method->is_initializer() &&
  77             caller_method != C->method() &&
  78             caller_method->holder()->is_subclass_of(callee_method->holder()))
  79          );
  80 }
  81 
  82 // positive filter: should send be inlined?  returns NULL, if yes, or rejection msg
  83 const char* InlineTree::shouldInline(ciMethod* callee_method, ciMethod* caller_method, int caller_bci, ciCallProfile& profile, WarmCallInfo* wci_result) const {
  84   // Allows targeted inlining
  85   if(callee_method->should_inline()) {
  86     *wci_result = *(WarmCallInfo::always_hot());
  87     if (PrintInlining && Verbose) {
  88       print_indent(inline_depth());
  89       tty->print_cr("Inlined method is hot: ");
  90     }
  91     return NULL;
  92   }
  93 
  94   // positive filter: should send be inlined?  returns NULL (--> yes)
  95   // or rejection msg
  96   int max_size = C->max_inline_size();
  97   int size     = callee_method->code_size();
  98 
  99   // Check for too many throws (and not too huge)
 100   if(callee_method->interpreter_throwout_count() > InlineThrowCount &&
 101      size < InlineThrowMaxSize ) {
 102     wci_result->set_profit(wci_result->profit() * 100);
 103     if (PrintInlining && Verbose) {
 104       print_indent(inline_depth());
 105       tty->print_cr("Inlined method with many throws (throws=%d):", callee_method->interpreter_throwout_count());
 106     }
 107     return NULL;
 108   }
 109 
 110   if (!UseOldInlining) {
 111     return NULL;  // size and frequency are represented in a new way
 112   }
 113 
 114   int call_site_count  = method()->scale_count(profile.count());
 115   int invoke_count     = method()->interpreter_invocation_count();
 116   assert( invoke_count != 0, "Require invokation count greater than zero");
 117   int freq = call_site_count/invoke_count;
 118 
 119   // bump the max size if the call is frequent
 120   if ((freq >= InlineFrequencyRatio) ||
 121       (call_site_count >= InlineFrequencyCount) ||
 122       is_init_with_ea(callee_method, caller_method, C)) {
 123 
 124     max_size = C->freq_inline_size();
 125     if (size <= max_size && TraceFrequencyInlining) {
 126       print_indent(inline_depth());
 127       tty->print_cr("Inlined frequent method (freq=%d count=%d):", freq, call_site_count);
 128       print_indent(inline_depth());
 129       callee_method->print();
 130       tty->cr();
 131     }
 132   } else {
 133     // Not hot.  Check for medium-sized pre-existing nmethod at cold sites.
 134     if (callee_method->has_compiled_code() &&
 135         callee_method->instructions_size() > InlineSmallCode/4)
 136       return "already compiled into a medium method";
 137   }
 138   if (size > max_size) {
 139     if (max_size > C->max_inline_size())
 140       return "hot method too big";
 141     return "too big";
 142   }
 143   return NULL;
 144 }
 145 
 146 
 147 // negative filter: should send NOT be inlined?  returns NULL, ok to inline, or rejection msg
 148 const char* InlineTree::shouldNotInline(ciMethod *callee_method, ciMethod* caller_method, WarmCallInfo* wci_result) const {
 149   // negative filter: should send NOT be inlined?  returns NULL (--> inline) or rejection msg
 150   if (!UseOldInlining) {
 151     const char* fail = NULL;
 152     if (callee_method->is_abstract())               fail = "abstract method";
 153     // note: we allow ik->is_abstract()
 154     if (!callee_method->holder()->is_initialized()) fail = "method holder not initialized";
 155     if (callee_method->is_native())                 fail = "native method";
 156 
 157     if (fail) {
 158       *wci_result = *(WarmCallInfo::always_cold());
 159       return fail;
 160     }
 161 
 162     if (callee_method->has_unloaded_classes_in_signature()) {
 163       wci_result->set_profit(wci_result->profit() * 0.1);
 164     }
 165 
 166     // don't inline exception code unless the top method belongs to an
 167     // exception class
 168     if (callee_method->holder()->is_subclass_of(C->env()->Throwable_klass())) {
 169       ciMethod* top_method = caller_jvms() ? caller_jvms()->of_depth(1)->method() : method();
 170       if (!top_method->holder()->is_subclass_of(C->env()->Throwable_klass())) {
 171         wci_result->set_profit(wci_result->profit() * 0.1);
 172       }
 173     }
 174 
 175     if (callee_method->has_compiled_code() && callee_method->instructions_size() > InlineSmallCode) {
 176       wci_result->set_profit(wci_result->profit() * 0.1);
 177       // %%% adjust wci_result->size()?
 178     }
 179 
 180     return NULL;
 181   }
 182 
 183   // Always inline MethodHandle methods.
 184   if (callee_method->is_method_handle_invoke())
 185     return NULL;
 186 
 187   // First check all inlining restrictions which are required for correctness
 188   if (callee_method->is_abstract())               return "abstract method";
 189   // note: we allow ik->is_abstract()
 190   if (!callee_method->holder()->is_initialized()) return "method holder not initialized";
 191   if (callee_method->is_native())                 return "native method";
 192   if (callee_method->has_unloaded_classes_in_signature()) return "unloaded signature classes";
 193 
 194   if (callee_method->should_inline()) {
 195     // ignore heuristic controls on inlining
 196     return NULL;
 197   }
 198 
 199   // Now perform checks which are heuristic
 200 
 201   if( callee_method->has_compiled_code() && callee_method->instructions_size() > InlineSmallCode )
 202     return "already compiled into a big method";
 203 
 204   // don't inline exception code unless the top method belongs to an
 205   // exception class
 206   if (caller_tree() != NULL &&
 207       callee_method->holder()->is_subclass_of(C->env()->Throwable_klass())) {
 208     const InlineTree *top = this;
 209     while (top->caller_tree() != NULL) top = top->caller_tree();
 210     ciInstanceKlass* k = top->method()->holder();
 211     if (!k->is_subclass_of(C->env()->Throwable_klass()))
 212       return "exception method";
 213   }
 214 
 215   // use frequency-based objections only for non-trivial methods
 216   if (callee_method->code_size() <= MaxTrivialSize) return NULL;
 217 
 218   // don't use counts with -Xcomp or CTW
 219   if (UseInterpreter && !CompileTheWorld) {
 220 
 221     if (!callee_method->has_compiled_code() &&
 222         !callee_method->was_executed_more_than(0)) {
 223       return "never executed";
 224     }
 225 
 226     if (is_init_with_ea(callee_method, caller_method, C)) {
 227 
 228       // Escape Analysis: inline all executed constructors
 229 
 230     } else if (!callee_method->was_executed_more_than(MIN2(MinInliningThreshold,
 231                                                            CompileThreshold >> 1))) {
 232       return "executed < MinInliningThreshold times";
 233     }
 234   }
 235 
 236   if (callee_method->should_not_inline()) {
 237     return "disallowed by CompilerOracle";
 238   }
 239 
 240   if (UseStringCache) {
 241     // Do not inline StringCache::profile() method used only at the beginning.
 242     if (callee_method->name() == ciSymbol::profile_name() &&
 243         callee_method->holder()->name() == ciSymbol::java_lang_StringCache()) {
 244       return "profiling method";
 245     }
 246   }
 247 
 248   return NULL;
 249 }
 250 
 251 //-----------------------------try_to_inline-----------------------------------
 252 // return NULL if ok, reason for not inlining otherwise
 253 // Relocated from "InliningClosure::try_to_inline"
 254 const char* InlineTree::try_to_inline(ciMethod* callee_method, ciMethod* caller_method, int caller_bci, ciCallProfile& profile, WarmCallInfo* wci_result) {
 255 
 256   // Old algorithm had funny accumulating BC-size counters
 257   if (UseOldInlining && ClipInlining
 258       && (int)count_inline_bcs() >= DesiredMethodLimit) {
 259     return "size > DesiredMethodLimit";
 260   }
 261 
 262   const char *msg = NULL;
 263   if ((msg = shouldInline(callee_method, caller_method, caller_bci,
 264                           profile, wci_result)) != NULL) {
 265     return msg;
 266   }
 267   if ((msg = shouldNotInline(callee_method, caller_method,
 268                              wci_result)) != NULL) {
 269     return msg;
 270   }
 271 
 272   bool is_accessor = InlineAccessors && callee_method->is_accessor();
 273 
 274   // suppress a few checks for accessors and trivial methods
 275   if (!is_accessor && callee_method->code_size() > MaxTrivialSize) {
 276 
 277     // don't inline into giant methods
 278     if (C->unique() > (uint)NodeCountInliningCutoff) {
 279       return "NodeCountInliningCutoff";
 280     }
 281 
 282     if ((!UseInterpreter || CompileTheWorld) &&
 283         is_init_with_ea(callee_method, caller_method, C)) {
 284 
 285       // Escape Analysis stress testing when running Xcomp or CTW:
 286       // inline constructors even if they are not reached.
 287 
 288     } else if (profile.count() == 0) {
 289       // don't inline unreached call sites
 290       return "call site not reached";
 291     }
 292   }
 293 
 294   if (!C->do_inlining() && InlineAccessors && !is_accessor) {
 295     return "not an accessor";
 296   }
 297   if( inline_depth() > MaxInlineLevel ) {
 298     return "inlining too deep";
 299   }
 300   if( method() == callee_method &&
 301       inline_depth() > MaxRecursiveInlineLevel ) {
 302     return "recursively inlining too deep";
 303   }
 304 
 305   int size = callee_method->code_size();
 306 
 307   if (UseOldInlining && ClipInlining
 308       && (int)count_inline_bcs() + size >= DesiredMethodLimit) {
 309     return "size > DesiredMethodLimit";
 310   }
 311 
 312   // ok, inline this method
 313   return NULL;
 314 }
 315 
 316 //------------------------------pass_initial_checks----------------------------
 317 bool pass_initial_checks(ciMethod* caller_method, int caller_bci, ciMethod* callee_method) {
 318   ciInstanceKlass *callee_holder = callee_method ? callee_method->holder() : NULL;
 319   // Check if a callee_method was suggested
 320   if( callee_method == NULL )            return false;
 321   // Check if klass of callee_method is loaded
 322   if( !callee_holder->is_loaded() )      return false;
 323   if( !callee_holder->is_initialized() ) return false;
 324   if( !UseInterpreter || CompileTheWorld /* running Xcomp or CTW */ ) {
 325     // Checks that constant pool's call site has been visited
 326     // stricter than callee_holder->is_initialized()
 327     ciBytecodeStream iter(caller_method);
 328     iter.force_bci(caller_bci);
 329     Bytecodes::Code call_bc = iter.cur_bc();
 330     // An invokedynamic instruction does not have a klass.
 331     if (call_bc != Bytecodes::_invokedynamic) {
 332       int index = iter.get_index_int();
 333       if (!caller_method->is_klass_loaded(index, true)) {
 334         return false;
 335       }
 336       // Try to do constant pool resolution if running Xcomp
 337       if( !caller_method->check_call(index, call_bc == Bytecodes::_invokestatic) ) {
 338         return false;
 339       }
 340     }
 341   }
 342   // We will attempt to see if a class/field/etc got properly loaded.  If it
 343   // did not, it may attempt to throw an exception during our probing.  Catch
 344   // and ignore such exceptions and do not attempt to compile the method.
 345   if( callee_method->should_exclude() )  return false;
 346 
 347   return true;
 348 }
 349 
 350 #ifndef PRODUCT
 351 //------------------------------print_inlining---------------------------------
 352 // Really, the failure_msg can be a success message also.
 353 void InlineTree::print_inlining(ciMethod *callee_method, int caller_bci, const char *failure_msg) const {
 354   print_indent(inline_depth());
 355   tty->print("@ %d  ", caller_bci);
 356   if( callee_method ) callee_method->print_short_name();
 357   else                tty->print(" callee not monotonic or profiled");
 358   tty->print("  %s", (failure_msg ? failure_msg : "inline"));
 359   if( Verbose && callee_method ) {
 360     const InlineTree *top = this;
 361     while( top->caller_tree() != NULL ) { top = top->caller_tree(); }
 362     tty->print("  bcs: %d+%d  invoked: %d", top->count_inline_bcs(), callee_method->code_size(), callee_method->interpreter_invocation_count());
 363   }
 364   tty->cr();
 365 }
 366 #endif
 367 
 368 //------------------------------ok_to_inline-----------------------------------
 369 WarmCallInfo* InlineTree::ok_to_inline(ciMethod* callee_method, JVMState* jvms, ciCallProfile& profile, WarmCallInfo* initial_wci) {
 370   assert(callee_method != NULL, "caller checks for optimized virtual!");
 371 #ifdef ASSERT
 372   // Make sure the incoming jvms has the same information content as me.
 373   // This means that we can eventually make this whole class AllStatic.
 374   if (jvms->caller() == NULL) {
 375     assert(_caller_jvms == NULL, "redundant instance state");
 376   } else {
 377     assert(_caller_jvms->same_calls_as(jvms->caller()), "redundant instance state");
 378   }
 379   assert(_method == jvms->method(), "redundant instance state");
 380 #endif
 381   const char *failure_msg   = NULL;
 382   int         caller_bci    = jvms->bci();
 383   ciMethod   *caller_method = jvms->method();
 384 
 385   if( !pass_initial_checks(caller_method, caller_bci, callee_method)) {
 386     if( PrintInlining ) {
 387       failure_msg = "failed_initial_checks";
 388       print_inlining( callee_method, caller_bci, failure_msg);
 389     }
 390     return NULL;
 391   }
 392 
 393   // Check if inlining policy says no.
 394   WarmCallInfo wci = *(initial_wci);
 395   failure_msg = try_to_inline(callee_method, caller_method, caller_bci, profile, &wci);
 396   if (failure_msg != NULL && C->log() != NULL) {
 397     C->log()->begin_elem("inline_fail reason='");
 398     C->log()->text("%s", failure_msg);
 399     C->log()->end_elem("'");
 400   }
 401 
 402 #ifndef PRODUCT
 403   if (UseOldInlining && InlineWarmCalls
 404       && (PrintOpto || PrintOptoInlining || PrintInlining)) {
 405     bool cold = wci.is_cold();
 406     bool hot  = !cold && wci.is_hot();
 407     bool old_cold = (failure_msg != NULL);
 408     if (old_cold != cold || (Verbose || WizardMode)) {
 409       tty->print("   OldInlining= %4s : %s\n           WCI=",
 410                  old_cold ? "cold" : "hot", failure_msg ? failure_msg : "OK");
 411       wci.print();
 412     }
 413   }
 414 #endif
 415   if (UseOldInlining) {
 416     if (failure_msg == NULL)
 417       wci = *(WarmCallInfo::always_hot());
 418     else
 419       wci = *(WarmCallInfo::always_cold());
 420   }
 421   if (!InlineWarmCalls) {
 422     if (!wci.is_cold() && !wci.is_hot()) {
 423       // Do not inline the warm calls.
 424       wci = *(WarmCallInfo::always_cold());
 425     }
 426   }
 427 
 428   if (!wci.is_cold()) {
 429     // In -UseOldInlining, the failure_msg may also be a success message.
 430     if (failure_msg == NULL)  failure_msg = "inline (hot)";
 431 
 432     // Inline!
 433     if( PrintInlining ) print_inlining( callee_method, caller_bci, failure_msg);
 434     if (UseOldInlining)
 435       build_inline_tree_for_callee(callee_method, jvms, caller_bci);
 436     if (InlineWarmCalls && !wci.is_hot())
 437       return new (C) WarmCallInfo(wci);  // copy to heap
 438     return WarmCallInfo::always_hot();
 439   }
 440 
 441   // Do not inline
 442   if (failure_msg == NULL)  failure_msg = "too cold to inline";
 443   if( PrintInlining ) print_inlining( callee_method, caller_bci, failure_msg);
 444   return NULL;
 445 }
 446 
 447 //------------------------------compute_callee_frequency-----------------------
 448 float InlineTree::compute_callee_frequency( int caller_bci ) const {
 449   int count  = method()->interpreter_call_site_count(caller_bci);
 450   int invcnt = method()->interpreter_invocation_count();
 451   float freq = (float)count/(float)invcnt;
 452   // Call-site count / interpreter invocation count, scaled recursively.
 453   // Always between 0.0 and 1.0.  Represents the percentage of the method's
 454   // total execution time used at this call site.
 455 
 456   return freq;
 457 }
 458 
 459 //------------------------------build_inline_tree_for_callee-------------------
 460 InlineTree *InlineTree::build_inline_tree_for_callee( ciMethod* callee_method, JVMState* caller_jvms, int caller_bci) {
 461   float recur_frequency = _site_invoke_ratio * compute_callee_frequency(caller_bci);
 462   // Attempt inlining.
 463   InlineTree* old_ilt = callee_at(caller_bci, callee_method);
 464   if (old_ilt != NULL) {
 465     return old_ilt;
 466   }
 467   InlineTree *ilt = new InlineTree( C, this, callee_method, caller_jvms, caller_bci, recur_frequency );
 468   _subtrees.append( ilt );
 469 
 470   NOT_PRODUCT( _count_inlines += 1; )
 471 
 472   return ilt;
 473 }
 474 
 475 
 476 //---------------------------------------callee_at-----------------------------
 477 InlineTree *InlineTree::callee_at(int bci, ciMethod* callee) const {
 478   for (int i = 0; i < _subtrees.length(); i++) {
 479     InlineTree* sub = _subtrees.at(i);
 480     if (sub->caller_bci() == bci && callee == sub->method()) {
 481       return sub;
 482     }
 483   }
 484   return NULL;
 485 }
 486 
 487 
 488 //------------------------------build_inline_tree_root-------------------------
 489 InlineTree *InlineTree::build_inline_tree_root() {
 490   Compile* C = Compile::current();
 491 
 492   // Root of inline tree
 493   InlineTree *ilt = new InlineTree(C, NULL, C->method(), NULL, -1, 1.0F);
 494 
 495   return ilt;
 496 }
 497 
 498 
 499 //-------------------------find_subtree_from_root-----------------------------
 500 // Given a jvms, which determines a call chain from the root method,
 501 // find the corresponding inline tree.
 502 // Note: This method will be removed or replaced as InlineTree goes away.
 503 InlineTree* InlineTree::find_subtree_from_root(InlineTree* root, JVMState* jvms, ciMethod* callee, bool create_if_not_found) {
 504   InlineTree* iltp = root;
 505   uint depth = jvms && jvms->has_method() ? jvms->depth() : 0;
 506   for (uint d = 1; d <= depth; d++) {
 507     JVMState* jvmsp  = jvms->of_depth(d);
 508     // Select the corresponding subtree for this bci.
 509     assert(jvmsp->method() == iltp->method(), "tree still in sync");
 510     ciMethod* d_callee = (d == depth) ? callee : jvms->of_depth(d+1)->method();
 511     InlineTree* sub = iltp->callee_at(jvmsp->bci(), d_callee);
 512     if (!sub) {
 513       if (create_if_not_found && d == depth) {
 514         return iltp->build_inline_tree_for_callee(d_callee, jvmsp, jvmsp->bci());
 515       }
 516       assert(sub != NULL, "should be a sub-ilt here");
 517       return NULL;
 518     }
 519     iltp = sub;
 520   }
 521   return iltp;
 522 }