1 /*
   2  * Copyright (c) 1999, 2010, 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 #ifndef SHARE_VM_C1_C1_VALUESTACK_HPP
  26 #define SHARE_VM_C1_C1_VALUESTACK_HPP
  27 
  28 #include "c1/c1_Instruction.hpp"
  29 
  30 class ValueStack: public CompilationResourceObj {
  31  public:
  32   enum Kind {
  33     Parsing,             // During abstract interpretation in GraphBuilder
  34     CallerState,         // Caller state when inlining
  35     StateBefore,         // Before before execution of instruction
  36     StateAfter,          // After execution of instruction
  37     ExceptionState,      // Exception handling of instruction
  38     EmptyExceptionState, // Exception handling of instructions not covered by an xhandler
  39     BlockBeginState      // State of BlockBegin instruction with phi functions of this block
  40   };
  41 
  42  private:
  43   IRScope* _scope;                               // the enclosing scope
  44   ValueStack* _caller_state;
  45   int      _bci;
  46   Kind     _kind;
  47 
  48   Values   _locals;                              // the locals
  49   Values   _stack;                               // the expression stack
  50   Values   _locks;                               // the monitor stack (holding the locked values)
  51 
  52   Value check(ValueTag tag, Value t) {
  53     assert(tag == t->type()->tag() || tag == objectTag && t->type()->tag() == addressTag, "types must correspond");
  54     return t;
  55   }
  56 
  57   Value check(ValueTag tag, Value t, Value h) {
  58     assert(h == NULL, "hi-word of doubleword value must be NULL");
  59     return check(tag, t);
  60   }
  61 
  62   // helper routine
  63   static void apply(Values list, ValueVisitor* f);
  64 
  65   // for simplified copying
  66   ValueStack(ValueStack* copy_from, Kind kind, int bci);
  67 
  68  public:
  69   // creation
  70   ValueStack(IRScope* scope, ValueStack* caller_state);
  71 
  72   ValueStack* copy()                             { return new ValueStack(this, _kind, _bci); }
  73   ValueStack* copy(Kind new_kind, int new_bci)   { return new ValueStack(this, new_kind, new_bci); }
  74   ValueStack* copy_for_parsing()                 { return new ValueStack(this, Parsing, -99); }
  75 
  76   void set_caller_state(ValueStack* s)           {
  77     assert(kind() == EmptyExceptionState ||
  78            (Compilation::current()->env()->jvmti_can_access_local_variables() && kind() == ExceptionState),
  79            "only EmptyExceptionStates can be modified");
  80     _caller_state = s;
  81   }
  82 
  83   bool is_same(ValueStack* s);                   // returns true if this & s's types match (w/o checking locals)
  84 
  85   // accessors
  86   IRScope* scope() const                         { return _scope; }
  87   ValueStack* caller_state() const               { return _caller_state; }
  88   int bci() const                                { return _bci; }
  89   Kind kind() const                              { return _kind; }
  90 
  91   int locals_size() const                        { return _locals.length(); }
  92   int stack_size() const                         { return _stack.length(); }
  93   int locks_size() const                         { return _locks.length(); }
  94   bool stack_is_empty() const                    { return _stack.is_empty(); }
  95   bool no_active_locks() const                   { return _locks.is_empty(); }
  96   int total_locks_size() const;
  97 
  98   // locals access
  99   void clear_locals();                           // sets all locals to NULL;
 100 
 101   void invalidate_local(int i) {
 102     assert(_locals.at(i)->type()->is_single_word() ||
 103            _locals.at(i + 1) == NULL, "hi-word of doubleword value must be NULL");
 104     _locals.at_put(i, NULL);
 105   }
 106 
 107   Value local_at(int i) const {
 108     Value x = _locals.at(i);
 109     assert(x == NULL || x->type()->is_single_word() ||
 110            _locals.at(i + 1) == NULL, "hi-word of doubleword value must be NULL");
 111     return x;
 112   }
 113 
 114   void store_local(int i, Value x) {
 115     // When overwriting local i, check if i - 1 was the start of a
 116     // double word local and kill it.
 117     if (i > 0) {
 118       Value prev = _locals.at(i - 1);
 119       if (prev != NULL && prev->type()->is_double_word()) {
 120         _locals.at_put(i - 1, NULL);
 121       }
 122     }
 123 
 124     _locals.at_put(i, x);
 125     if (x->type()->is_double_word()) {
 126       // hi-word of doubleword value is always NULL
 127       _locals.at_put(i + 1, NULL);
 128     }
 129   }
 130 
 131   // stack access
 132   Value stack_at(int i) const {
 133     Value x = _stack.at(i);
 134     assert(x->type()->is_single_word() ||
 135            _stack.at(i + 1) == NULL, "hi-word of doubleword value must be NULL");
 136     return x;
 137   }
 138 
 139   Value stack_at_inc(int& i) const {
 140     Value x = stack_at(i);
 141     i += x->type()->size();
 142     return x;
 143   }
 144 
 145   // pinning support
 146   void pin_stack_for_linear_scan();
 147 
 148   // iteration
 149   void values_do(ValueVisitor* f);
 150 
 151   // untyped manipulation (for dup_x1, etc.)
 152   void truncate_stack(int size)                  { _stack.trunc_to(size); }
 153   void raw_push(Value t)                         { _stack.push(t); }
 154   Value raw_pop()                                { return _stack.pop(); }
 155 
 156   // typed manipulation
 157   void ipush(Value t)                            { _stack.push(check(intTag    , t)); }
 158   void fpush(Value t)                            { _stack.push(check(floatTag  , t)); }
 159   void apush(Value t)                            { _stack.push(check(objectTag , t)); }
 160   void rpush(Value t)                            { _stack.push(check(addressTag, t)); }
 161   void lpush(Value t)                            { _stack.push(check(longTag   , t)); _stack.push(NULL); }
 162   void dpush(Value t)                            { _stack.push(check(doubleTag , t)); _stack.push(NULL); }
 163 
 164   void push(ValueType* type, Value t) {
 165     switch (type->tag()) {
 166       case intTag    : ipush(t); return;
 167       case longTag   : lpush(t); return;
 168       case floatTag  : fpush(t); return;
 169       case doubleTag : dpush(t); return;
 170       case objectTag : apush(t); return;
 171       case addressTag: rpush(t); return;
 172     }
 173     ShouldNotReachHere();
 174   }
 175 
 176   Value ipop()                                   { return check(intTag    , _stack.pop()); }
 177   Value fpop()                                   { return check(floatTag  , _stack.pop()); }
 178   Value apop()                                   { return check(objectTag , _stack.pop()); }
 179   Value rpop()                                   { return check(addressTag, _stack.pop()); }
 180   Value lpop()                                   { Value h = _stack.pop(); return check(longTag  , _stack.pop(), h); }
 181   Value dpop()                                   { Value h = _stack.pop(); return check(doubleTag, _stack.pop(), h); }
 182 
 183   Value pop(ValueType* type) {
 184     switch (type->tag()) {
 185       case intTag    : return ipop();
 186       case longTag   : return lpop();
 187       case floatTag  : return fpop();
 188       case doubleTag : return dpop();
 189       case objectTag : return apop();
 190       case addressTag: return rpop();
 191     }
 192     ShouldNotReachHere();
 193     return NULL;
 194   }
 195 
 196   Values* pop_arguments(int argument_size);
 197 
 198   // locks access
 199   int lock  (Value obj);
 200   int unlock();
 201   Value lock_at(int i) const                     { return _locks.at(i); }
 202 
 203   // SSA form IR support
 204   void setup_phi_for_stack(BlockBegin* b, int index);
 205   void setup_phi_for_local(BlockBegin* b, int index);
 206 
 207   // debugging
 208   void print()  PRODUCT_RETURN;
 209   void verify() PRODUCT_RETURN;
 210 };
 211 
 212 
 213 
 214 // Macro definitions for simple iteration of stack and local values of a ValueStack
 215 // The macros can be used like a for-loop. All variables (state, index and value)
 216 // must be defined before the loop.
 217 // When states are nested because of inlining, the stack of the innermost state
 218 // cumulates also the stack of the nested states. In contrast, the locals of all
 219 // states must be iterated each.
 220 // Use the following code pattern to iterate all stack values and all nested local values:
 221 //
 222 // ValueStack* state = ...   // state that is iterated
 223 // int index;                // current loop index (overwritten in loop)
 224 // Value value;              // value at current loop index (overwritten in loop)
 225 //
 226 // for_each_stack_value(state, index, value {
 227 //   do something with value and index
 228 // }
 229 //
 230 // for_each_state(state) {
 231 //   for_each_local_value(state, index, value) {
 232 //     do something with value and index
 233 //   }
 234 // }
 235 // as an invariant, state is NULL now
 236 
 237 
 238 // construct a unique variable name with the line number where the macro is used
 239 #define temp_var3(x) temp__ ## x
 240 #define temp_var2(x) temp_var3(x)
 241 #define temp_var     temp_var2(__LINE__)
 242 
 243 #define for_each_state(state)  \
 244   for (; state != NULL; state = state->caller_state())
 245 
 246 #define for_each_local_value(state, index, value)                                              \
 247   int temp_var = state->locals_size();                                                         \
 248   for (index = 0;                                                                              \
 249        index < temp_var && (value = state->local_at(index), true);                             \
 250        index += (value == NULL || value->type()->is_illegal() ? 1 : value->type()->size()))    \
 251     if (value != NULL)
 252 
 253 
 254 #define for_each_stack_value(state, index, value)                                              \
 255   int temp_var = state->stack_size();                                                          \
 256   for (index = 0;                                                                              \
 257        index < temp_var && (value = state->stack_at(index), true);                             \
 258        index += value->type()->size())
 259 
 260 
 261 #define for_each_lock_value(state, index, value)                                               \
 262   int temp_var = state->locks_size();                                                          \
 263   for (index = 0;                                                                              \
 264        index < temp_var && (value = state->lock_at(index), true);                              \
 265        index++)                                                                                \
 266     if (value != NULL)
 267 
 268 
 269 // Macro definition for simple iteration of all state values of a ValueStack
 270 // Because the code cannot be executed in a single loop, the code must be passed
 271 // as a macro parameter.
 272 // Use the following code pattern to iterate all stack values and all nested local values:
 273 //
 274 // ValueStack* state = ...   // state that is iterated
 275 // for_each_state_value(state, value,
 276 //   do something with value (note that this is a macro parameter)
 277 // );
 278 
 279 #define for_each_state_value(v_state, v_value, v_code)                                         \
 280 {                                                                                              \
 281   int cur_index;                                                                               \
 282   ValueStack* cur_state = v_state;                                                             \
 283   Value v_value;                                                                               \
 284   for_each_state(cur_state) {                                                                  \
 285     {                                                                                            \
 286       for_each_local_value(cur_state, cur_index, v_value) {                                      \
 287         v_code;                                                                                  \
 288       }                                                                                          \
 289     }                                                                                          \
 290     {                                                                                            \
 291       for_each_stack_value(cur_state, cur_index, v_value) {                                      \
 292         v_code;                                                                                  \
 293       }                                                                                          \
 294     }                                                                                            \
 295   }                                                                                            \
 296 }
 297 
 298 
 299 // Macro definition for simple iteration of all phif functions of a block, i.e all
 300 // phi functions of the ValueStack where the block matches.
 301 // Use the following code pattern to iterate all phi functions of a block:
 302 //
 303 // BlockBegin* block = ...   // block that is iterated
 304 // for_each_phi_function(block, phi,
 305 //   do something with the phi function phi (note that this is a macro parameter)
 306 // );
 307 
 308 #define for_each_phi_fun(v_block, v_phi, v_code)                                               \
 309 {                                                                                              \
 310   int cur_index;                                                                               \
 311   ValueStack* cur_state = v_block->state();                                                    \
 312   Value value;                                                                                 \
 313   {                                                                                            \
 314     for_each_stack_value(cur_state, cur_index, value) {                                        \
 315       Phi* v_phi = value->as_Phi();                                                      \
 316       if (v_phi != NULL && v_phi->block() == v_block) {                                        \
 317         v_code;                                                                                \
 318       }                                                                                        \
 319     }                                                                                          \
 320   }                                                                                            \
 321   {                                                                                            \
 322     for_each_local_value(cur_state, cur_index, value) {                                        \
 323       Phi* v_phi = value->as_Phi();                                                      \
 324       if (v_phi != NULL && v_phi->block() == v_block) {                                        \
 325         v_code;                                                                                \
 326       }                                                                                        \
 327     }                                                                                          \
 328   }                                                                                            \
 329 }
 330 
 331 #endif // SHARE_VM_C1_C1_VALUESTACK_HPP