# Simulator main loop for IQ2000. -*- C -*-
# Copyright (C) 1998-2024 Free Software Foundation, Inc.
# Contributed by Cygnus Solutions.
#
# This file is part of the GNU Simulators.
#
# 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/>.

# Syntax:
# /bin/sh mainloop.in command
#
# Command is one of:
#
# init
# support
# extract-{simple,scache,pbb}
# {full,fast}-exec-{simple,scache,pbb}
#
# A target need only provide a "full" version of one of simple,scache,pbb.
# If the target wants it can also provide a fast version of same.
# It can't provide more than this, however for illustration's sake the IQ2000
# port provides examples of all.

# ??? After a few more ports are done, revisit.
# Will eventually need to machine generate a lot of this.

case "x$1" in

xsupport)

cat <<EOF
#line $LINENO "$0"
#include <stdlib.h>

static INLINE const IDESC *
extract (SIM_CPU *current_cpu, PCADDR pc, CGEN_INSN_INT insn, ARGBUF *abuf,
         int fast_p)
{
  const IDESC *id = @cpu@_decode (current_cpu, pc, insn, insn, abuf);
  @cpu@_fill_argbuf (current_cpu, abuf, id, pc, fast_p);
  if (! fast_p)
    {
      int trace_p = PC_IN_TRACE_RANGE_P (current_cpu, pc);
      int profile_p = PC_IN_PROFILE_RANGE_P (current_cpu, pc);
      @cpu@_fill_argbuf_tp (current_cpu, abuf, trace_p, profile_p);
    }
  return id;
}

static INLINE SEM_PC
execute (SIM_CPU *current_cpu, SCACHE *sc, int fast_p)
{
  SEM_PC vpc;

  /* Force R0 to zero before every insn.  */
  @cpu@_h_gr_set (current_cpu, 0, 0);

  if (fast_p)
    {
#if ! WITH_SEM_SWITCH_FAST
#if WITH_SCACHE
      vpc = (*sc->argbuf.semantic.sem_fast) (current_cpu, sc);
#else
      vpc = (*sc->argbuf.semantic.sem_fast) (current_cpu, &sc->argbuf);
#endif
#else
      abort ();
#endif /* WITH_SEM_SWITCH_FAST */
    }
  else
    {
#if ! WITH_SEM_SWITCH_FULL
      ARGBUF *abuf = &sc->argbuf;
      const IDESC *idesc = abuf->idesc;
#if WITH_SCACHE_PBB
      int virtual_p = CGEN_ATTR_VALUE (NULL, idesc->attrs, CGEN_INSN_VIRTUAL);
#else
      int virtual_p = 0;
#endif

      if (! virtual_p)
	{
	  /* FIXME: call x-before */
	  if (ARGBUF_PROFILE_P (abuf))
	    PROFILE_COUNT_INSN (current_cpu, abuf->addr, idesc->num);
	  /* FIXME: Later make cover macros: PROFILE_INSN_{INIT,FINI}.  */
	  if (PROFILE_MODEL_P (current_cpu)
	      && ARGBUF_PROFILE_P (abuf))
	    @cpu@_model_insn_before (current_cpu, 1 /*first_p*/);
	  CGEN_TRACE_INSN_INIT (current_cpu, abuf, 1);
	  CGEN_TRACE_INSN (current_cpu, idesc->idata,
		      (const struct argbuf *) abuf, abuf->addr);
	}
#if WITH_SCACHE
      vpc = (*sc->argbuf.semantic.sem_full) (current_cpu, sc);
#else
      vpc = (*sc->argbuf.semantic.sem_full) (current_cpu, abuf);
#endif
      if (! virtual_p)
	{
	  /* FIXME: call x-after */
	  if (PROFILE_MODEL_P (current_cpu)
	      && ARGBUF_PROFILE_P (abuf))
	    {
	      int cycles;

	      cycles = (*idesc->timing->model_fn) (current_cpu, sc);
	      @cpu@_model_insn_after (current_cpu, 1 /*last_p*/, cycles);
	    }
	  CGEN_TRACE_INSN_FINI (current_cpu, abuf, 1);
	}
#else
      abort ();
#endif /* WITH_SEM_SWITCH_FULL */
    }

  return vpc;
}

EOF
;;

xinit)
;;

xextract-simple | xextract-scache)

# Inputs:  current_cpu, vpc, sc, FAST_P
# Outputs: sc filled in

cat <<EOF
#line $LINENO "$0"
{
  CGEN_INSN_INT insn = GETIMEMUSI (current_cpu, CPU2INSN(vpc));
  extract (current_cpu, vpc, insn, SEM_ARGBUF (sc), FAST_P);
  SEM_SKIP_COMPILE (current_cpu, sc, 1);
}
EOF

;;

xextract-pbb)

# Inputs:  current_cpu, pc, sc, max_insns, FAST_P
# Outputs: sc, pc
# sc must be left pointing past the last created entry.
# pc must be left pointing past the last created entry.
# If the pbb is terminated by a cti insn, SET_CTI_VPC(sc) must be called
# to record the vpc of the cti insn.
# SET_INSN_COUNT(n) must be called to record number of real insns.

cat <<EOF
#line $LINENO "$0"
{
  const IDESC *idesc;
  int icount = 0;

  /* Is the CTI instruction at the end of the PBB a likely branch?  */
  int likely_cti;

  while (max_insns > 0)
    {
      USI insn = GETIMEMUSI (current_cpu, CPU2INSN(pc));
      
      idesc = extract (current_cpu, pc, insn, &sc->argbuf, FAST_P);
      SEM_SKIP_COMPILE (current_cpu, sc, 1);
      ++sc;
      --max_insns;
      ++icount;
      pc += idesc->length;

      if (IDESC_CTI_P (idesc))
        {
          /* Likely branches annul their delay slot if the branch is
	     not taken by using the (skip ..) rtx.  We'll rely on
	     that.  */
          likely_cti = (IDESC_SKIP_P (idesc));

          SET_CTI_VPC (sc - 1);

          if (CGEN_ATTR_VALUE (NULL, idesc->attrs, CGEN_INSN_DELAY_SLOT))
	    {
              insn = GETIMEMUSI (current_cpu, CPU2INSN(pc));
	      idesc = extract (current_cpu, pc, insn, &sc->argbuf, FAST_P);

              if (likely_cti && IDESC_CTI_P (idesc))
	        {
	          /* malformed program */
	          sim_io_eprintf (CPU_STATE (current_cpu),
		    "malformed program, \`%s' insn in branch likely delay slot\n",
		    CGEN_INSN_NAME (idesc->idata));
	        }
	      else
	        {
	          ++sc;
	          --max_insns;
	          ++icount;
	          pc += idesc->length;
	        }
            }  
	  break;
	}
    }

 Finish:
  SET_INSN_COUNT (icount);
}
EOF

;;

xfull-exec-* | xfast-exec-*)

# Inputs: current_cpu, sc, FAST_P
# Outputs: vpc
# vpc contains the address of the next insn to execute

cat <<EOF
#line $LINENO "$0"
{
#if (! FAST_P && WITH_SEM_SWITCH_FULL) || (FAST_P && WITH_SEM_SWITCH_FAST)
#define DEFINE_SWITCH
#include "sem-switch.c"
#else
  vpc = execute (current_cpu, vpc, FAST_P);
#endif
}
EOF

;;

*)
  echo "Invalid argument to mainloop.in: $1" >&2
  exit 1
  ;;

esac