/*
 * Copyright (c) 2001 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 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, write to the Free Software
 *    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */
#if !defined(WINNT)
#ident "$Id: vpi_signal.cc,v 1.4 2001/03/25 19:38:05 steve Exp $"
#endif

/*
 * vpiReg handles are handled here. These objects represent vectors of
 * .var objects that can be manipulated by the VPI module.
 */

# include  "vpi_priv.h"
# include  "functor.h"
# include  <malloc.h>
# include  <assert.h>

extern const char hex_digits[256];

/*
 * implement vpi_get for vpiReg objects.
 */
static int signal_get(int code, vpiHandle ref)
{
      assert((ref->vpi_type->type_code==vpiNet)
	     || (ref->vpi_type->type_code==vpiReg));

      struct __vpiSignal*rfp = (struct __vpiSignal*)ref;

      switch (code) {

	  case vpiSigned:
	    return 0;

	  case vpiSize:
	    if (rfp->msb >= rfp->lsb)
		  return rfp->msb - rfp->lsb + 1;
	    else
		  return rfp->lsb - rfp->msb + 1;

	  default:
	    return 0;
      }
}

static char* signal_get_str(int code, vpiHandle ref)
{
      assert((ref->vpi_type->type_code==vpiNet)
	     || (ref->vpi_type->type_code==vpiReg));

      struct __vpiSignal*rfp = (struct __vpiSignal*)ref;

      switch (code) {

	  case vpiFullName:
	    return (char*)rfp->name;
      }

      return 0;
}

static char buf[4096];

/*
 * The get_value method reads the values of the functors and returns
 * the vector to the caller. This causes no side-effect, and reads the
 * variables like a %load would.
 */
static void signal_get_value(vpiHandle ref, s_vpi_value*vp)
{
      static const char bit_char[4] = { '0', '1', 'x', 'z' };

      assert((ref->vpi_type->type_code==vpiNet)
	     || (ref->vpi_type->type_code==vpiReg));

      struct __vpiSignal*rfp = (struct __vpiSignal*)ref;

      unsigned wid = (rfp->msb >= rfp->lsb)
	    ? (rfp->msb - rfp->lsb + 1)
	    : (rfp->lsb - rfp->msb + 1);

      switch (vp->format) {

	  case vpiBinStrVal:
	    for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
		  vvp_ipoint_t fptr = ipoint_index(rfp->bits, idx);
		  functor_t fp = functor_index(fptr);
		  buf[wid-idx-1] = bit_char[fp->oval&3];
	    }
	    buf[wid] = 0;
	    vp->value.str = buf;
	    break;

	  case vpiHexStrVal: {
		unsigned hval, hwid;
		hwid = (wid + 3) / 4;
		buf[hwid] = 0;
		hval = 0;
		for (unsigned idx = 0 ;  idx < wid ;  idx += 1) {
		      vvp_ipoint_t fptr = ipoint_index(rfp->bits, idx);
		      functor_t fp = functor_index(fptr);
		      hval = hval | ((fp->oval&3) << 2*(idx % 4));

		      if (idx%4 == 3) {
			    hwid -= 1;
			    buf[hwid] = hex_digits[hval];
			    hval = 0;
		      }
		}

		if (hwid > 0) {
		      hwid -= 1;
		      buf[hwid] = hex_digits[hval];
		      hval = 0;
		}
		vp->value.str = buf;
		break;
	  }

	  default:
	      /* XXXX Not implemented yet. */
	    assert(0);
      }
}

/*
 * The put_value method writes the value into the vector, and returns
 * the affected ref. This operation works much like the %set or
 * %assign instructions and causes all the side-effects that the
 * equivilent instruction would cause.
 */
static vpiHandle signal_put_value(vpiHandle ref, s_vpi_value*vp,
			     p_vpi_time when, int flags)
{
      assert((ref->vpi_type->type_code==vpiNet)
	     || (ref->vpi_type->type_code==vpiReg));

      struct __vpiSignal*rfp = (struct __vpiSignal*)ref;

	/* XXXX Not implemented yet. */
      assert(0);

      return ref;
}


static const struct __vpirt vpip_reg_rt = {
      vpiReg,
      signal_get,
      signal_get_str,
      signal_get_value,
      signal_put_value,
      0,
      0
};

static const struct __vpirt vpip_net_rt = {
      vpiNet,
      signal_get,
      signal_get_str,
      signal_get_value,
      signal_put_value,
      0,
      0
};

/*
 * Construct a vpiReg object. Give the object specified dimensions,
 * and point to the specified functor for the lsb.
 */
vpiHandle vpip_make_reg(char*name, int msb, int lsb, vvp_ipoint_t base)
{
      struct __vpiSignal*obj = (struct __vpiSignal*)
	    malloc(sizeof(struct __vpiSignal));
      obj->base.vpi_type = &vpip_reg_rt;
      obj->name = name;
      obj->msb = msb;
      obj->lsb = lsb;
      obj->bits = base;

      obj->scope = vpip_peek_current_scope();

      return &obj->base;
}


/*
 * Construct a vpiReg object. Give the object specified dimensions,
 * and point to the specified functor for the lsb.
 */
vpiHandle vpip_make_net(char*name, int msb, int lsb, vvp_ipoint_t base)
{
      struct __vpiSignal*obj = (struct __vpiSignal*)
	    malloc(sizeof(struct __vpiSignal));
      obj->base.vpi_type = &vpip_net_rt;
      obj->name = name;
      obj->msb = msb;
      obj->lsb = lsb;
      obj->bits = base;

      obj->scope = vpip_peek_current_scope();

      return &obj->base;
}


/*
 * $Log: vpi_signal.cc,v $
 * Revision 1.4  2001/03/25 19:38:05  steve
 *  Support making hex strings.
 *
 * Revision 1.3  2001/03/25 00:35:35  steve
 *  Add the .net statement.
 *
 * Revision 1.2  2001/03/21 05:13:03  steve
 *  Allow var objects as vpiHandle arguments to %vpi_call.
 *
 * Revision 1.1  2001/03/20 06:16:24  steve
 *  Add support for variable vectors.
 *
 */