1135 
1136   // An id of a speculation that JVMCI compiled code can use to further describe and
1137   // uniquely identify the  speculative optimization guarded by the uncommon trap
1138   jlong     _pending_failed_speculation;
1139 
1140   // These fields are mutually exclusive in terms of live ranges.
1141   union {
1142     // Communicates the pc at which the most recent implicit exception occurred
1143     // from the signal handler to a deoptimization stub.
1144     address   _implicit_exception_pc;
1145 
1146     // Communicates an alternative call target to an i2c stub from a JavaCall .
1147     address   _alternate_call_target;
1148   } _jvmci;
1149 
1150   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1151   jlong*    _jvmci_counters;
1152 
1153  public:
1154   static jlong* _jvmci_old_thread_counters;
1155   static void collect_counters(JVMCIEnv* JVMCIENV, JVMCIPrimitiveArray array);
1156  private:
1157 #endif // INCLUDE_JVMCI
1158 
1159   StackGuardState  _stack_guard_state;
1160 
1161   // Precompute the limit of the stack as used in stack overflow checks.
1162   // We load it from here to simplify the stack overflow check in assembly.
1163   address          _stack_overflow_limit;
1164   address          _reserved_stack_activation;
1165 
1166   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1167   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1168   // code)
1169   volatile oop     _exception_oop;               // Exception thrown in compiled code
1170   volatile address _exception_pc;                // PC where exception happened
1171   volatile address _exception_handler_pc;        // PC for handler of exception
1172   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1173 
1174  private:
1175   // support for JNI critical regions

1135 
1136   // An id of a speculation that JVMCI compiled code can use to further describe and
1137   // uniquely identify the  speculative optimization guarded by the uncommon trap
1138   jlong     _pending_failed_speculation;
1139 
1140   // These fields are mutually exclusive in terms of live ranges.
1141   union {
1142     // Communicates the pc at which the most recent implicit exception occurred
1143     // from the signal handler to a deoptimization stub.
1144     address   _implicit_exception_pc;
1145 
1146     // Communicates an alternative call target to an i2c stub from a JavaCall .
1147     address   _alternate_call_target;
1148   } _jvmci;
1149 
1150   // Support for high precision, thread sensitive counters in JVMCI compiled code.
1151   jlong*    _jvmci_counters;
1152 
1153  public:
1154   static jlong* _jvmci_old_thread_counters;
1155   static void collect_counters(jlong* array, int length);
1156  private:
1157 #endif // INCLUDE_JVMCI
1158 
1159   StackGuardState  _stack_guard_state;
1160 
1161   // Precompute the limit of the stack as used in stack overflow checks.
1162   // We load it from here to simplify the stack overflow check in assembly.
1163   address          _stack_overflow_limit;
1164   address          _reserved_stack_activation;
1165 
1166   // Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
1167   // used to temp. parsing values into and out of the runtime system during exception handling for compiled
1168   // code)
1169   volatile oop     _exception_oop;               // Exception thrown in compiled code
1170   volatile address _exception_pc;                // PC where exception happened
1171   volatile address _exception_handler_pc;        // PC for handler of exception
1172   volatile int     _is_method_handle_return;     // true (== 1) if the current exception PC is a MethodHandle call site.
1173 
1174  private:
1175   // support for JNI critical regions