1 /*

     2  * Copyright 2005 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 //  Simulates the FPU stack and maintains mapping [fpu-register -> stack offset]

    26 //  FPU registers are described as numbers from 0..nof_fpu_regs-1

    27 

    28 class Compilation;

    29 

    30 class FpuStackSim VALUE_OBJ_CLASS_SPEC {

    31  private:

    32   Compilation* _compilation;

    33   int          _stack_size;

    34   int          _regs[FrameMap::nof_fpu_regs];

    35 

    36   int tos_index() const                        { return _stack_size - 1; }

    37 

    38   int regs_at(int i) const;

    39   void set_regs_at(int i, int val);

    40   void dec_stack_size();

    41   void inc_stack_size();

    42 

    43   // unified bailout support

    44   Compilation*  compilation() const              { return _compilation; }

    45   void          bailout(const char* msg) const   { compilation()->bailout(msg); }

    46   bool          bailed_out() const               { return compilation()->bailed_out(); }

    47 

    48  public:

    49   FpuStackSim(Compilation* compilation);

    50   void pop ();

    51   void pop (int rnr);                          // rnr must be on tos

    52   void push(int rnr);

    53   void swap(int offset);                       // exchange tos with tos + offset

    54   int offset_from_tos(int rnr) const;          // return the offset of the topmost instance of rnr from TOS

    55   int  get_slot(int tos_offset) const;         // return the entry at the given offset from TOS

    56   void set_slot(int tos_offset, int rnr);      // set the entry at the given offset from TOS

    57   void rename(int old_rnr, int new_rnr);       // rename all instances of old_rnr to new_rnr

    58   bool contains(int rnr);                      // debugging support only

    59   bool is_empty();

    60   bool slot_is_empty(int tos_offset);

    61   int stack_size() const                       { return _stack_size; }

    62   void clear();

    63   intArray* write_state();

    64   void read_state(intArray* fpu_stack_state);

    65 

    66   void print() PRODUCT_RETURN;

    67 };