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 /*

  * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

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  */

 // A frame represents a physical stack frame (an activation).  Frames can be

 // C or Java frames, and the Java frames can be interpreted or compiled.

 // In contrast, vframes represent source-level activations, so that one physical frame

 // can correspond to multiple source level frames because of inlining.

 // A frame is comprised of {pc, sp, younger_sp}

 // Layout of asm interpreter frame:

 //

 //  0xfffffff

 //  ......

 // [last  extra incoming arg,  (local # Nargs > 6 ? Nargs-1 : undef)]

 // .. Note: incoming args are copied to local frame area upon entry

 // [first extra incoming arg,  (local # Nargs > 6 ? 6       : undef)]

 // [6 words for C-arg storage (unused)] Are this and next one really needed?

 // [C-aggregate-word (unused)] Yes, if want extra params to be  in same place as C convention

 // [16 words for register saving]                                    <--- FP

 // [interpreter_frame_vm_locals ] (see below)

 //              Note: Llocals is always double-word aligned

 // [first local i.e. local # 0]        <-- Llocals

 // ...

 // [last local, i.e. local # Nlocals-1]

 // [monitors                 ]

 // ....

 // [monitors                 ]    <-- Lmonitors (same as Llocals + 6*4 if none)

 //                                    (must be double-word aligned because

 //                                     monitor element size is constrained to

 //                                     doubleword)

 //

 //                                <-- Lesp (points 1 past TOS)

 // [bottom word used for stack ]

 // ...

 // [top word used for stack]    (first word of stack is double-word aligned)

 // [space for outgoing args (conservatively allocated as max_stack - 6 + interpreter_frame_extra_outgoing_argument_words)]

 // [6 words for C-arg storage]

 // [C-aggregate-word (unused)]

 // [16 words for register saving]                                    <--- SP

 // ...

 // 0x0000000

 //

 // The in registers and local registers are preserved in a block at SP.

 //

 // The first six in registers (I0..I5) hold the first six locals.

 // The locals are used as follows:

 //    Lesp         first free element of expression stack

 //                 (which grows towards __higher__ addresses)

 //    Lbcp         is set to address of bytecode to execute

 //                 It is accessed in the frame under the name "bcx".

 //                 It may at times (during GC) be an index instead.

 //    Lmethod      the method being interpreted

 //    Llocals      the base pointer for accessing the locals array

 //                 (lower-numbered locals have lower addresses)

 //    Lmonitors    the base pointer for accessing active monitors

 //    Lcache       a saved pointer to the method's constant pool cache

 //

 //

 // When calling out to another method,

 // G5_method is set to method to call, G5_inline_cache_klass may be set,

 // parameters are put in O registers, and also extra parameters

 // must be cleverly copied from the top of stack to the outgoing param area in the frame,

 // ------------------------------ C++ interpreter ----------------------------------------

 // Layout of C++ interpreter frame:

 //

 // All frames:

  public:

   enum {

     // normal return address is 2 words past PC

     pc_return_offset                             = 2 * BytesPerInstWord,

     // size of each block, in order of increasing address:

     register_save_words                          = 16,

 #ifdef _LP64

     callee_aggregate_return_pointer_words        =  0,

 #else

     callee_aggregate_return_pointer_words        =  1,

 #endif

     callee_register_argument_save_area_words     =  6,

     // memory_parameter_words                    = <arbitrary>,

     // offset of each block, in order of increasing address:

     // (note: callee_register_argument_save_area_words == Assembler::n_register_parameters)

     register_save_words_sp_offset                = 0,

     callee_aggregate_return_pointer_sp_offset    = register_save_words_sp_offset + register_save_words,

     callee_register_argument_save_area_sp_offset = callee_aggregate_return_pointer_sp_offset + callee_aggregate_return_pointer_words,

     memory_parameter_word_sp_offset              = callee_register_argument_save_area_sp_offset + callee_register_argument_save_area_words,

     varargs_offset                               = memory_parameter_word_sp_offset

   };

  private:

   intptr_t*  _younger_sp;                 // optional SP of callee (used to locate O7)

   int        _sp_adjustment_by_callee;   // adjustment in words to SP by callee for making locals contiguous

   // Note:  On SPARC, unlike Intel, the saved PC for a stack frame

   // is stored at a __variable__ distance from that frame's SP.

   // (In fact, it may be in the register save area of the callee frame,

   // but that fact need not bother us.)  Thus, we must store the

   // address of that saved PC explicitly.  On the other hand, SPARC

   // stores the FP for a frame at a fixed offset from the frame's SP,

   // so there is no need for a separate "frame::_fp" field.

  public:

   // Accessors

   intptr_t* younger_sp() const {

     assert(_younger_sp != NULL, "frame must possess a younger_sp");

     return _younger_sp;

   }

   int callee_sp_adjustment() const { return _sp_adjustment_by_callee; }

   void set_sp_adjustment_by_callee(int number_of_words) { _sp_adjustment_by_callee = number_of_words; }

   // Constructors

   // This constructor relies on the fact that the creator of a frame

   // has flushed register windows which the frame will refer to, and

   // that those register windows will not be reloaded until the frame is

   // done reading and writing the stack.  Moreover, if the "younger_sp"

   // argument points into the register save area of the next younger

   // frame (though it need not), the register window for that next

   // younger frame must also stay flushed.  (The caller is responsible

   // for ensuring this.)

   frame(intptr_t* sp, intptr_t* younger_sp, bool younger_frame_adjusted_stack = false);

   // make a deficient frame which doesn't know where its PC is:

   enum unpatchable_t { unpatchable };

   frame(intptr_t* sp, unpatchable_t, address pc = NULL, CodeBlob* cb = NULL);

   // Walk from sp outward looking for old_sp, and return old_sp's predecessor

   // (i.e. return the sp from the frame where old_sp is the fp).

   // Register windows are assumed to be flushed for the stack in question.

   static intptr_t* next_younger_sp_or_null(intptr_t* old_sp, intptr_t* sp);

   // Return true if sp is a younger sp in the stack described by valid_sp.

   static bool is_valid_stack_pointer(intptr_t* valid_sp, intptr_t* sp);

  public:

   // accessors for the instance variables

   intptr_t*   fp() const { return (intptr_t*) ((intptr_t)(sp()[FP->sp_offset_in_saved_window()]) + STACK_BIAS ); }

   // All frames

   intptr_t*  fp_addr_at(int index) const   { return &fp()[index];    }

   intptr_t*  sp_addr_at(int index) const   { return &sp()[index];    }

   intptr_t   fp_at(     int index) const   { return *fp_addr_at(index); }

   intptr_t   sp_at(     int index) const   { return *sp_addr_at(index); }

  private:

   inline address* I7_addr() const;

   inline address* O7_addr() const;

   inline address* I0_addr() const;

   inline address* O0_addr() const;

   intptr_t*  younger_sp_addr_at(int index) const   { return &younger_sp()[index];    }

  public:

   // access to SPARC arguments and argument registers

   // Assumes reg is an in/local register

   intptr_t*     register_addr(Register reg) const {

     return sp_addr_at(reg->sp_offset_in_saved_window());

   }

   // Assumes reg is an out register

   intptr_t*     out_register_addr(Register reg) const {

     return younger_sp_addr_at(reg->after_save()->sp_offset_in_saved_window());

   }

   intptr_t* memory_param_addr(int param_ix, bool is_in) const {

     int offset = callee_register_argument_save_area_sp_offset + param_ix;

     if (is_in)

       return fp_addr_at(offset);

     else

       return sp_addr_at(offset);

   }

   intptr_t*        param_addr(int param_ix, bool is_in) const {

     if (param_ix >= callee_register_argument_save_area_words)

       return memory_param_addr(param_ix, is_in);

     else if (is_in)

       return register_addr(Argument(param_ix, true).as_register());

     else {

       // the registers are stored in the next younger frame

       // %%% is this really necessary?

       ShouldNotReachHere();

       return NULL;

     }

   }

   // Interpreter frames

  public:

   // Asm interpreter

 #ifndef CC_INTERP

   enum interpreter_frame_vm_locals {

        // 2 words, also used to save float regs across  calls to C

        interpreter_frame_d_scratch_fp_offset          = -2,

        interpreter_frame_l_scratch_fp_offset          = -4,

        interpreter_frame_padding_offset               = -5, // for native calls only

        interpreter_frame_oop_temp_offset              = -6, // for native calls only

        interpreter_frame_vm_locals_fp_offset          = -6, // should be same as above, and should be zero mod 8

        interpreter_frame_vm_local_words = -interpreter_frame_vm_locals_fp_offset,

        // interpreter frame set-up needs to save 2 extra words in outgoing param area

        // for class and jnienv arguments for native stubs (see nativeStubGen_sparc.cpp_

        interpreter_frame_extra_outgoing_argument_words = 2

   };

 #else

   enum interpreter_frame_vm_locals {

        // 2 words, also used to save float regs across  calls to C

        interpreter_state_ptr_offset                   = 0,  // Is in L0 (Lstate) in save area

        interpreter_frame_mirror_offset                = 1,  // Is in L1 (Lmirror) in save area (for native calls only)

        // interpreter frame set-up needs to save 2 extra words in outgoing param area

        // for class and jnienv arguments for native stubs (see nativeStubGen_sparc.cpp_

        interpreter_frame_extra_outgoing_argument_words = 2

   };

 #endif /* CC_INTERP */

   // the compiler frame has many of the same fields as the interpreter frame

   // %%%%% factor out declarations of the shared fields

   enum compiler_frame_fixed_locals {

        compiler_frame_d_scratch_fp_offset          = -2,

        compiler_frame_vm_locals_fp_offset          = -2, // should be same as above

        compiler_frame_vm_local_words = -compiler_frame_vm_locals_fp_offset

   };

  private:

   constantPoolCacheOop* frame::interpreter_frame_cpoolcache_addr() const;

 #ifndef CC_INTERP

   // where Lmonitors is saved:

   BasicObjectLock**  interpreter_frame_monitors_addr() const {

     return (BasicObjectLock**) sp_addr_at(Lmonitors->sp_offset_in_saved_window());

   }

   intptr_t** interpreter_frame_esp_addr() const {

     return (intptr_t**)sp_addr_at(Lesp->sp_offset_in_saved_window());

   }

   inline void interpreter_frame_set_tos_address(intptr_t* x);

   // %%%%% Another idea: instead of defining 3 fns per item, just define one returning a ref

   // monitors:

   // next two fns read and write Lmonitors value,

  private:

   BasicObjectLock* interpreter_frame_monitors()           const  { return *interpreter_frame_monitors_addr(); }

   void interpreter_frame_set_monitors(BasicObjectLock* monitors) {        *interpreter_frame_monitors_addr() = monitors; }

 #else

  public:

   inline interpreterState get_interpreterState() const {

     return ((interpreterState)sp_at(interpreter_state_ptr_offset));

   }

 #endif /* CC_INTERP */

  // Compiled frames

  public:

   // Tells if this register can hold 64 bits on V9 (really, V8+).

   static bool holds_a_doubleword(Register reg) {

 #ifdef _LP64

     //    return true;

     return reg->is_out() || reg->is_global();

 #else

     return reg->is_out() || reg->is_global();

 #endif

   }