/* Architecture, machine, and model support.
   Copyright (C) 1997-2018 Free Software Foundation, Inc.
   Contributed by Cygnus Support.

This file is part of GDB, the GNU debugger.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program 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 for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Nomenclature:
   architecture = one of sparc, mips, sh, etc.
   in the sparc architecture, mach = one of v6, v7, v8, sparclite, etc.
   in the v8 mach, model = one of supersparc, etc.

   To use the model framework, your arch needs to do a few things:
   (1) Call SIM_AC_OPTION_DEFAULT_MODEL() in configure.ac.
   (2) Define enum mach_attr in sim-main.h.
   (3) Define sim_machs array (and all the callbacks it uses).
*/

/* This file is intended to be included by sim-basics.h.  */

#ifndef SIM_MODEL_H
#define SIM_MODEL_H

/* Function unit and instruction timing support.
   ??? This is obviously insufficiently general.
   It's useful but it needs elaborating upon.  */

typedef struct {
  unsigned char name; /* actually a UNIT_TYPE enum */
  unsigned char issue;
  unsigned char done;
} UNIT;

#ifndef MAX_UNITS
#define MAX_UNITS 1
#endif

#ifndef WITH_DEFAULT_MODEL
/* Just a stub for ports that do not define models.  */
enum mach_attr { _MACH_NONE };
# define WITH_DEFAULT_MODEL NULL
# define WITH_MODEL_P 0
#else
# define WITH_MODEL_P 1
#endif

typedef int (MODEL_FN) (sim_cpu *, void *);

typedef struct {
  /* This is an integer that identifies this insn.
     How this works is up to the target.  */
  int num;

  /* Function to handle insn-specific profiling.  */
  MODEL_FN *model_fn;

  /* Array of function units used by this insn.  */
  UNIT units[MAX_UNITS];
} INSN_TIMING;

/* Struct to describe various implementation properties of a cpu.
   When multiple cpu variants are supported, the sizes of some structs
   can vary.  */

typedef struct {
  /* The size of the SIM_CPU struct.  */
  int sim_cpu_size;
#define IMP_PROPS_SIM_CPU_SIZE(cpu_props) ((cpu_props)->sim_cpu_size)
  /* An SCACHE element can vary in size, depending on the selected cpu.
     This is zero if the SCACHE isn't in use for this variant.  */
  int scache_elm_size;
#define IMP_PROPS_SCACHE_ELM_SIZE(cpu_props) ((cpu_props)->scache_elm_size)
} SIM_MACH_IMP_PROPERTIES;

/* A machine variant.  */

typedef struct {
  const char *name;
#define MACH_NAME(m) ((m)->name)
  /* This is the argument to bfd_scan_arch.  */
  const char *bfd_name;
#define MACH_BFD_NAME(m) ((m)->bfd_name)
  enum mach_attr num;
#define MACH_NUM(m) ((m)->num)

  int word_bitsize;
#define MACH_WORD_BITSIZE(m) ((m)->word_bitsize)
  int addr_bitsize;
#define MACH_ADDR_BITSIZE(m) ((m)->addr_bitsize)

  /* Pointer to null-entry terminated table of models of this mach.
     The default is the first one.  */
  const struct model *models;
#define MACH_MODELS(m) ((m)->models)

  /* Pointer to the implementation properties of this mach.  */
  const SIM_MACH_IMP_PROPERTIES *imp_props;
#define MACH_IMP_PROPS(m) ((m)->imp_props)

  /* Called by sim_model_set when the model of a cpu is set.  */
  void (* init_cpu) (sim_cpu *);
#define MACH_INIT_CPU(m) ((m)->init_cpu)

  /* Initialize the simulator engine for this cpu.
     Used by cgen simulators to initialize the insn descriptor table.  */
  void (* prepare_run) (sim_cpu *);
#define MACH_PREPARE_RUN(m) ((m)->prepare_run)
} SIM_MACH;

/* A model (implementation) of a machine.  */

typedef struct model {
  const char *name;
#define MODEL_NAME(m) ((m)->name)
  const SIM_MACH *mach;
#define MODEL_MACH(m) ((m)->mach)
  /* An enum that distinguished the model.  */
  int num;
#define MODEL_NUM(m) ((m)->num)
  /* Pointer to timing table for this model.  */
  const INSN_TIMING *timing;
#define MODEL_TIMING(m) ((m)->timing)
  void (* init) (sim_cpu *);
#define MODEL_INIT(m) ((m)->init)
} SIM_MODEL;

/* Tables of supported machines.  */
/* ??? In a simulator of multiple architectures, will need multiple copies of
   this.  Have an `archs' array that contains a pointer to the machs array
   for each (which in turn has a pointer to the models array for each).  */
extern const SIM_MACH *sim_machs[];

/* Model module handlers.  */
extern MODULE_INSTALL_FN sim_model_install;

/* Support routines.  */
extern void sim_model_set (SIM_DESC sd_, sim_cpu *cpu_, const SIM_MODEL *model_);
extern const SIM_MODEL *sim_model_lookup (const char *name_);
extern const SIM_MACH *sim_mach_lookup (const char *name_);
extern const SIM_MACH *sim_mach_lookup_bfd_name (const char *bfd_name_);

#endif /* SIM_MODEL_H */