1 /*

     2  * Copyright (c) 1999, 2016, 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 "c1/c1_IR.hpp"

    27 #include "c1/c1_InstructionPrinter.hpp"

    28 #include "c1/c1_ValueStack.hpp"

    29 

    30 

    31 // Implementation of ValueStack

    32 

    33 ValueStack::ValueStack(IRScope* scope, ValueStack* caller_state)

    34 : _scope(scope)

    35 , _caller_state(caller_state)

    36 , _bci(-99)

    37 , _kind(Parsing)

    38 , _locals(scope->method()->max_locals(), scope->method()->max_locals(), NULL)

    39 , _stack(scope->method()->max_stack())

    40 , _locks()

    41 {

    42   verify();

    43 }

    44 

    45 

    46 ValueStack::ValueStack(ValueStack* copy_from, Kind kind, int bci)

    47   : _scope(copy_from->scope())

    48   , _caller_state(copy_from->caller_state())

    49   , _bci(bci)

    50   , _kind(kind)

    51   , _locals()

    52   , _stack()

    53   , _locks(copy_from->locks_size())

    54 {

    55   assert(kind != EmptyExceptionState || !Compilation::current()->env()->should_retain_local_variables(), "need locals");

    56   if (kind != EmptyExceptionState) {

    57     // only allocate space if we need to copy the locals-array

    58     _locals = Values(copy_from->locals_size());

    59     _locals.appendAll(&copy_from->_locals);

    60   }

    61 

    62   if (kind != ExceptionState && kind != EmptyExceptionState) {

    63     if (kind == Parsing) {

    64       // stack will be modified, so reserve enough space to avoid resizing

    65       _stack = Values(scope()->method()->max_stack());

    66     } else {

    67       // stack will not be modified, so do not waste space

    68       _stack = Values(copy_from->stack_size());

    69     }

    70     _stack.appendAll(&copy_from->_stack);

    71   }

    72 

    73   _locks.appendAll(&copy_from->_locks);

    74 

    75   verify();

    76 }

    77 

    78 

    79 bool ValueStack::is_same(ValueStack* s) {

    80   if (scope() != s->scope()) return false;

    81   if (caller_state() != s->caller_state()) return false;

    82 

    83   if (locals_size() != s->locals_size()) return false;

    84   if (stack_size() != s->stack_size()) return false;

    85   if (locks_size() != s->locks_size()) return false;

    86 

    87   // compare each stack element with the corresponding stack element of s

    88   int index;

    89   Value value;

    90   for_each_stack_value(this, index, value) {

    91     if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false;

    92   }

    93   for_each_lock_value(this, index, value) {

    94     if (value != s->lock_at(index)) return false;

    95   }

    96   return true;

    97 }

    98 

    99 void ValueStack::clear_locals() {

   100   for (int i = _locals.length() - 1; i >= 0; i--) {

   101     _locals.at_put(i, NULL);

   102   }

   103 }

   104 

   105 

   106 void ValueStack::pin_stack_for_linear_scan() {

   107   for_each_state_value(this, v,

   108     if (v->as_Constant() == NULL && v->as_Local() == NULL) {

   109       v->pin(Instruction::PinStackForStateSplit);

   110     }

   111   );

   112 }

   113 

   114 

   115 // apply function to all values of a list; factored out from values_do(f)

   116 void ValueStack::apply(Values list, ValueVisitor* f) {

   117   for (int i = 0; i < list.length(); i++) {

   118     Value* va = list.adr_at(i);

   119     Value v0 = *va;

   120     if (v0 != NULL && !v0->type()->is_illegal()) {

   121       f->visit(va);

   122 #ifdef ASSERT

   123       Value v1 = *va;

   124       assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match");

   125       assert(!v1->type()->is_double_word() || list.at(i + 1) == NULL, "hi-word of doubleword value must be NULL");

   126 #endif

   127       if (v0->type()->is_double_word()) i++;

   128     }

   129   }

   130 }

   131 

   132 

   133 void ValueStack::values_do(ValueVisitor* f) {

   134   ValueStack* state = this;

   135   for_each_state(state) {

   136     apply(state->_locals, f);

   137     apply(state->_stack, f);

   138     apply(state->_locks, f);

   139   }

   140 }

   141 

   142 

   143 Values* ValueStack::pop_arguments(int argument_size) {

   144   assert(stack_size() >= argument_size, "stack too small or too many arguments");

   145   int base = stack_size() - argument_size;

   146   Values* args = new Values(argument_size);

   147   for (int i = base; i < stack_size();) args->push(stack_at_inc(i));

   148   truncate_stack(base);

   149   return args;

   150 }

   151 

   152 

   153 int ValueStack::total_locks_size() const {

   154   int num_locks = 0;

   155   const ValueStack* state = this;

   156   for_each_state(state) {

   157     num_locks += state->locks_size();

   158   }

   159   return num_locks;

   160 }

   161 

   162 int ValueStack::lock(Value obj) {

   163   _locks.push(obj);

   164   int num_locks = total_locks_size();

   165   scope()->set_min_number_of_locks(num_locks);

   166   return num_locks - 1;

   167 }

   168 

   169 

   170 int ValueStack::unlock() {

   171   _locks.pop();

   172   return total_locks_size();

   173 }

   174 

   175 

   176 void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) {

   177   assert(stack_at(index)->as_Phi() == NULL || stack_at(index)->as_Phi()->block() != b, "phi function already created");

   178 

   179   ValueType* t = stack_at(index)->type();

   180   Value phi = new Phi(t, b, -index - 1);

   181   _stack.at_put(index, phi);

   182 

   183   assert(!t->is_double_word() || _stack.at(index + 1) == NULL, "hi-word of doubleword value must be NULL");

   184 }

   185 

   186 void ValueStack::setup_phi_for_local(BlockBegin* b, int index) {

   187   assert(local_at(index)->as_Phi() == NULL || local_at(index)->as_Phi()->block() != b, "phi function already created");

   188 

   189   ValueType* t = local_at(index)->type();

   190   Value phi = new Phi(t, b, index);

   191   store_local(index, phi);

   192 }

   193 

   194 #ifndef PRODUCT

   195 

   196 void ValueStack::print() {

   197   scope()->method()->print_name();

   198   tty->cr();

   199   if (stack_is_empty()) {

   200     tty->print_cr("empty stack");

   201   } else {

   202     InstructionPrinter ip;

   203     for (int i = 0; i < stack_size();) {

   204       Value t = stack_at_inc(i);

   205       tty->print("%2d  ", i);

   206       tty->print("%c%d ", t->type()->tchar(), t->id());

   207       ip.print_instr(t);

   208       tty->cr();

   209     }

   210   }

   211   if (!no_active_locks()) {

   212     InstructionPrinter ip;

   213     for (int i = 0; i < locks_size(); i++) {

   214       Value t = lock_at(i);

   215       tty->print("lock %2d  ", i);

   216       if (t == NULL) {

   217         tty->print("this");

   218       } else {

   219         tty->print("%c%d ", t->type()->tchar(), t->id());

   220         ip.print_instr(t);

   221       }

   222       tty->cr();

   223     }

   224   }

   225   if (locals_size() > 0) {

   226     InstructionPrinter ip;

   227     for (int i = 0; i < locals_size();) {

   228       Value l = _locals.at(i);

   229       tty->print("local %d ", i);

   230       if (l == NULL) {

   231         tty->print("null");

   232         i ++;

   233       } else {

   234         tty->print("%c%d ", l->type()->tchar(), l->id());

   235         ip.print_instr(l);

   236         if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2;

   237       }

   238       tty->cr();

   239     }

   240   }

   241 

   242   if (caller_state() != NULL) {

   243     caller_state()->print();

   244   }

   245 }

   246 

   247 

   248 void ValueStack::verify() {

   249   assert(scope() != NULL, "scope must exist");

   250   if (caller_state() != NULL) {

   251     assert(caller_state()->scope() == scope()->caller(), "invalid caller scope");

   252     caller_state()->verify();

   253   }

   254 

   255   if (kind() == Parsing) {

   256     assert(bci() == -99, "bci not defined during parsing");

   257   } else {

   258     assert(bci() >= -1, "bci out of range");

   259     assert(bci() < scope()->method()->code_size(), "bci out of range");

   260     assert(bci() == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(bci())), "make sure bci points at a real bytecode");

   261     assert(scope()->method()->liveness_at_bci(bci()).is_valid(), "liveness at bci must be valid");

   262   }

   263 

   264   int i;

   265   for (i = 0; i < stack_size(); i++) {

   266     Value v = _stack.at(i);

   267     if (v == NULL) {

   268       assert(_stack.at(i - 1)->type()->is_double_word(), "only hi-words are NULL on stack");

   269     } else if (v->type()->is_double_word()) {

   270       assert(_stack.at(i + 1) == NULL, "hi-word must be NULL");

   271     }

   272   }

   273 

   274   for (i = 0; i < locals_size(); i++) {

   275     Value v = _locals.at(i);

   276     if (v != NULL && v->type()->is_double_word()) {

   277       assert(_locals.at(i + 1) == NULL, "hi-word must be NULL");

   278     }

   279   }

   280 

   281   for_each_state_value(this, v,

   282     assert(v != NULL, "just test if state-iteration succeeds");

   283   );

   284 }

   285 #endif // PRODUCT