iverilog/vvm/vvm_idiv.cc

158 lines
3.7 KiB
C++

/*
* Copyright (c) 2000 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
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: vvm_idiv.cc,v 1.3 2002/08/12 01:35:07 steve Exp $"
#endif
# include "config.h"
# include "vvm_func.h"
# include "vvm_gates.h"
# include <assert.h>
void vvm_binop_idiv(vvm_bitset_t&v, const vvm_bitset_t&l, const vvm_bitset_t&r)
{
assert(v.get_width() <= 8*sizeof(unsigned long));
assert(l.get_width() <= 8*sizeof(unsigned long));
assert(r.get_width() <= 8*sizeof(unsigned long));
unsigned long lv = 0, rv = 0;
unsigned long vv;
for (unsigned idx = 0 ; idx < l.get_width() ; idx += 1) {
if (B_ISXZ(l[idx]))
goto unknown_result;
if (B_IS1(l[idx]))
lv |= 1 << idx;
}
for (unsigned idx = 0 ; idx < r.get_width() ; idx += 1) {
if (B_ISXZ(r[idx]))
goto unknown_result;
if (B_IS1(r[idx]))
rv |= 1 << idx;
}
if (rv == 0)
goto unknown_result;
vv = lv / rv;
for (unsigned idx = 0 ; idx < v.get_width() ; idx += 1) {
if (vv & 1)
v[idx] = St1;
else
v[idx] = St0;
vv >>= 1;
}
return;
unknown_result:
for (unsigned idx= 0 ; idx < v.get_width() ; idx += 1)
v[idx] = StX;
}
vvm_idiv::vvm_idiv(unsigned rwid, unsigned awid, unsigned bwid)
: rwid_(rwid), awid_(awid), bwid_(bwid)
{
bits_ = new vpip_bit_t[rwid_+awid_+bwid_];
for (unsigned idx = 0 ; idx < rwid_+awid_+bwid_ ; idx += 1)
bits_[idx] = StX;
out_ = new vvm_nexus::drive_t[rwid];
}
vvm_idiv::~vvm_idiv()
{
delete[]out_;
delete[]bits_;
}
void vvm_idiv::init_DataA(unsigned idx, vpip_bit_t val)
{
assert(idx < awid_);
bits_[rwid_+idx] = val;
}
void vvm_idiv::init_DataB(unsigned idx, vpip_bit_t val)
{
assert(idx < bwid_);
bits_[rwid_+awid_+idx] = val;
}
vvm_nexus::drive_t* vvm_idiv::config_rout(unsigned idx)
{
assert(idx < rwid_);
return out_+idx;
}
unsigned vvm_idiv::key_DataA(unsigned idx) const
{
assert(idx < awid_);
return rwid_+idx;
}
unsigned vvm_idiv::key_DataB(unsigned idx) const
{
assert(idx < bwid_);
return rwid_+awid_+idx;
}
void vvm_idiv::take_value(unsigned key, vpip_bit_t val)
{
if (B_EQ(bits_[key], val)) {
bits_[key] = val;
return;
}
bits_[key] = val;
vvm_bitset_t r (bits_, rwid_);
vvm_bitset_t a (bits_+rwid_, awid_);
vvm_bitset_t b (bits_+rwid_+awid_, bwid_);
vvm_binop_idiv(r, a, b);
for (unsigned idx = 0 ; idx < rwid_ ; idx += 1)
out_[idx].set_value(bits_[idx]);
}
/*
* $Log: vvm_idiv.cc,v $
* Revision 1.3 2002/08/12 01:35:07 steve
* conditional ident string using autoconfig.
*
* Revision 1.2 2001/07/25 03:10:50 steve
* Create a config.h.in file to hold all the config
* junk, and support gcc 3.0. (Stephan Boettcher)
*
* Revision 1.1 2000/04/01 21:40:23 steve
* Add support for integer division.
*
*/