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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 
check(ValueTag tag,Value t)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 
check(ValueTag tag,Value t,Value h)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 
copy()72   ValueStack* copy()                             { return new ValueStack(this, _kind, _bci); }
copy(Kind new_kind,int new_bci)73   ValueStack* copy(Kind new_kind, int new_bci)   { return new ValueStack(this, new_kind, new_bci); }
copy_for_parsing()74   ValueStack* copy_for_parsing()                 { return new ValueStack(this, Parsing, -99); }
75 
set_caller_state(ValueStack * s)76   void set_caller_state(ValueStack* s)           {
77     assert(kind() == EmptyExceptionState ||
78            (Compilation::current()->env()->should_retain_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
scope() const86   IRScope* scope() const                         { return _scope; }
caller_state() const87   ValueStack* caller_state() const               { return _caller_state; }
bci() const88   int bci() const                                { return _bci; }
kind() const89   Kind kind() const                              { return _kind; }
90 
locals_size() const91   int locals_size() const                        { return _locals.length(); }
stack_size() const92   int stack_size() const                         { return _stack.length(); }
locks_size() const93   int locks_size() const                         { return _locks.length(); }
stack_is_empty() const94   bool stack_is_empty() const                    { return _stack.is_empty(); }
no_active_locks() const95   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 
invalidate_local(int i)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 
local_at(int i) const107   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 
store_local(int i,Value x)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
stack_at(int i) const132   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 
stack_at_inc(int & i) const139   Value stack_at_inc(int& i) const {
140     Value x = stack_at(i);
141     i += x->type()->size();
142     return x;
143   }
144 
stack_at_put(int i,Value x)145   void stack_at_put(int i, Value x) {
146     _stack.at_put(i, x);
147   }
148 
149   // pinning support
150   void pin_stack_for_linear_scan();
151 
152   // iteration
153   void values_do(ValueVisitor* f);
154 
155   // untyped manipulation (for dup_x1, etc.)
truncate_stack(int size)156   void truncate_stack(int size)                  { _stack.trunc_to(size); }
raw_push(Value t)157   void raw_push(Value t)                         { _stack.push(t); }
raw_pop()158   Value raw_pop()                                { return _stack.pop(); }
159 
160   // typed manipulation
ipush(Value t)161   void ipush(Value t)                            { _stack.push(check(intTag    , t)); }
fpush(Value t)162   void fpush(Value t)                            { _stack.push(check(floatTag  , t)); }
apush(Value t)163   void apush(Value t)                            { _stack.push(check(objectTag , t)); }
rpush(Value t)164   void rpush(Value t)                            { _stack.push(check(addressTag, t)); }
lpush(Value t)165   void lpush(Value t)                            { _stack.push(check(longTag   , t)); _stack.push(NULL); }
dpush(Value t)166   void dpush(Value t)                            { _stack.push(check(doubleTag , t)); _stack.push(NULL); }
167 
push(ValueType * type,Value t)168   void push(ValueType* type, Value t) {
169     switch (type->tag()) {
170       case intTag    : ipush(t); return;
171       case longTag   : lpush(t); return;
172       case floatTag  : fpush(t); return;
173       case doubleTag : dpush(t); return;
174       case objectTag : apush(t); return;
175       case addressTag: rpush(t); return;
176     }
177     ShouldNotReachHere();
178   }
179 
ipop()180   Value ipop()                                   { return check(intTag    , _stack.pop()); }
fpop()181   Value fpop()                                   { return check(floatTag  , _stack.pop()); }
apop()182   Value apop()                                   { return check(objectTag , _stack.pop()); }
rpop()183   Value rpop()                                   { return check(addressTag, _stack.pop()); }
lpop()184   Value lpop()                                   { Value h = _stack.pop(); return check(longTag  , _stack.pop(), h); }
dpop()185   Value dpop()                                   { Value h = _stack.pop(); return check(doubleTag, _stack.pop(), h); }
186 
pop(ValueType * type)187   Value pop(ValueType* type) {
188     switch (type->tag()) {
189       case intTag    : return ipop();
190       case longTag   : return lpop();
191       case floatTag  : return fpop();
192       case doubleTag : return dpop();
193       case objectTag : return apop();
194       case addressTag: return rpop();
195     }
196     ShouldNotReachHere();
197     return NULL;
198   }
199 
200   Values* pop_arguments(int argument_size);
201 
202   // locks access
203   int lock  (Value obj);
204   int unlock();
lock_at(int i) const205   Value lock_at(int i) const                     { return _locks.at(i); }
206 
207   // SSA form IR support
208   void setup_phi_for_stack(BlockBegin* b, int index);
209   void setup_phi_for_local(BlockBegin* b, int index);
210 
211   // debugging
212   void print()  PRODUCT_RETURN;
213   void verify() PRODUCT_RETURN;
214 };
215 
216 
217 
218 // Macro definitions for simple iteration of stack and local values of a ValueStack
219 // The macros can be used like a for-loop. All variables (state, index and value)
220 // must be defined before the loop.
221 // When states are nested because of inlining, the stack of the innermost state
222 // cumulates also the stack of the nested states. In contrast, the locals of all
223 // states must be iterated each.
224 // Use the following code pattern to iterate all stack values and all nested local values:
225 //
226 // ValueStack* state = ...   // state that is iterated
227 // int index;                // current loop index (overwritten in loop)
228 // Value value;              // value at current loop index (overwritten in loop)
229 //
230 // for_each_stack_value(state, index, value {
231 //   do something with value and index
232 // }
233 //
234 // for_each_state(state) {
235 //   for_each_local_value(state, index, value) {
236 //     do something with value and index
237 //   }
238 // }
239 // as an invariant, state is NULL now
240 
241 
242 // construct a unique variable name with the line number where the macro is used
243 #define temp_var3(x) temp__ ## x
244 #define temp_var2(x) temp_var3(x)
245 #define temp_var     temp_var2(__LINE__)
246 
247 #define for_each_state(state)  \
248   for (; state != NULL; state = state->caller_state())
249 
250 #define for_each_local_value(state, index, value)                                              \
251   int temp_var = state->locals_size();                                                         \
252   for (index = 0;                                                                              \
253        index < temp_var && (value = state->local_at(index), true);                             \
254        index += (value == NULL || value->type()->is_illegal() ? 1 : value->type()->size()))    \
255     if (value != NULL)
256 
257 
258 #define for_each_stack_value(state, index, value)                                              \
259   int temp_var = state->stack_size();                                                          \
260   for (index = 0;                                                                              \
261        index < temp_var && (value = state->stack_at(index), true);                             \
262        index += value->type()->size())
263 
264 
265 #define for_each_lock_value(state, index, value)                                               \
266   int temp_var = state->locks_size();                                                          \
267   for (index = 0;                                                                              \
268        index < temp_var && (value = state->lock_at(index), true);                              \
269        index++)                                                                                \
270     if (value != NULL)
271 
272 
273 // Macro definition for simple iteration of all state values of a ValueStack
274 // Because the code cannot be executed in a single loop, the code must be passed
275 // as a macro parameter.
276 // Use the following code pattern to iterate all stack values and all nested local values:
277 //
278 // ValueStack* state = ...   // state that is iterated
279 // for_each_state_value(state, value,
280 //   do something with value (note that this is a macro parameter)
281 // );
282 
283 #define for_each_state_value(v_state, v_value, v_code)                                         \
284 {                                                                                              \
285   int cur_index;                                                                               \
286   ValueStack* cur_state = v_state;                                                             \
287   Value v_value;                                                                               \
288   for_each_state(cur_state) {                                                                  \
289     {                                                                                            \
290       for_each_local_value(cur_state, cur_index, v_value) {                                      \
291         v_code;                                                                                  \
292       }                                                                                          \
293     }                                                                                          \
294     {                                                                                            \
295       for_each_stack_value(cur_state, cur_index, v_value) {                                      \
296         v_code;                                                                                  \
297       }                                                                                          \
298     }                                                                                            \
299   }                                                                                            \
300 }
301 
302 
303 // Macro definition for simple iteration of all phif functions of a block, i.e all
304 // phi functions of the ValueStack where the block matches.
305 // Use the following code pattern to iterate all phi functions of a block:
306 //
307 // BlockBegin* block = ...   // block that is iterated
308 // for_each_phi_function(block, phi,
309 //   do something with the phi function phi (note that this is a macro parameter)
310 // );
311 
312 #define for_each_phi_fun(v_block, v_phi, v_code)                                               \
313 {                                                                                              \
314   int cur_index;                                                                               \
315   ValueStack* cur_state = v_block->state();                                                    \
316   Value value;                                                                                 \
317   {                                                                                            \
318     for_each_stack_value(cur_state, cur_index, value) {                                        \
319       Phi* v_phi = value->as_Phi();                                                      \
320       if (v_phi != NULL && v_phi->block() == v_block) {                                        \
321         v_code;                                                                                \
322       }                                                                                        \
323     }                                                                                          \
324   }                                                                                            \
325   {                                                                                            \
326     for_each_local_value(cur_state, cur_index, value) {                                        \
327       Phi* v_phi = value->as_Phi();                                                      \
328       if (v_phi != NULL && v_phi->block() == v_block) {                                        \
329         v_code;                                                                                \
330       }                                                                                        \
331     }                                                                                          \
332   }                                                                                            \
333 }
334 
335 #endif // SHARE_VM_C1_C1_VALUESTACK_HPP
336