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Constant propagate addresses through NetRamDq read ports.

This commit is contained in:
steve 2006-04-23 04:26:13 +00:00
parent 94c9af2a5d
commit e0bbfa512c
5 changed files with 97 additions and 6 deletions
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63
cprop.cc
View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 1998-2003 Stephen Williams (steve@icarus.com)
* Copyright (c) 1998-2006 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
@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: cprop.cc,v 1.47.2.4 2005/09/11 02:50:51 steve Exp $"
#ident "$Id: cprop.cc,v 1.47.2.5 2006/04/23 04:26:13 steve Exp $"
#endif
# include "config.h"
@ -25,6 +25,7 @@
# include "netlist.h"
# include "netmisc.h"
# include "functor.h"
# include "compiler.h"
# include <assert.h>
@ -48,6 +49,8 @@ struct cprop_functor : public functor_t {
virtual void lpm_logic(Design*des, NetLogic*obj);
virtual void lpm_mux(Design*des, NetMux*obj);
virtual void lpm_mux_large(Design*des, NetMux*obj);
virtual void lpm_ram_dq(Design*des, NetRamDq*obj);
bool lpm_ram_dq_const_address_(Design*des, NetRamDq*obj);
};
void cprop_functor::signal(Design*des, NetNet*obj)
@ -1142,6 +1145,59 @@ void cprop_functor::lpm_mux_large(Design*des, NetMux*obj)
count += 1;
}
void cprop_functor::lpm_ram_dq(Design*des, NetRamDq*obj)
{
if (lpm_ram_dq_const_address_(des,obj))
return;
}
/*
* Try to evaluate a constant address input. If we find it, then
* replace the NetRamDq with a direct link to the addressed word.
*/
bool cprop_functor::lpm_ram_dq_const_address_(Design*des, NetRamDq*obj)
{
NetMemory*mem = obj->mem();
NetNet* reg = mem->reg_from_explode();
/* I only know how to do this on exploded memories. */
if (reg == 0)
return false;
verinum sel (0UL, obj->awidth());
for (unsigned idx = 0 ; idx < obj->awidth() ; idx += 1) {
if (! obj->pin_Address(idx).nexus()->drivers_constant())
return false;
sel.set(idx, obj->pin_Address(idx).nexus()->driven_value());
}
unsigned long address = sel.as_ulong();
/* If the address is outside the ram, then leave this to the
code generator to figure out. */
if (address >= obj->size())
return false;
unsigned base = address * obj->width();
assert(base+obj->width() <= reg->pin_count());
for (unsigned idx = 0 ; idx < obj->width() ; idx += 1)
connect(reg->pin(base+idx), obj->pin_Q(idx));
if (debug_cprop) {
cerr << obj->get_line() << ": debug: Replace read port with"
<< " fixed link to word " << address << "." << endl;
}
delete obj;
count += 1;
return true;
}
/*
* This functor looks to see if the constant is connected to nothing
* but signals. If that is the case, delete the dangling constant and
@ -1260,6 +1316,9 @@ void cprop(Design*des)
/*
* $Log: cprop.cc,v $
* Revision 1.47.2.5 2006/04/23 04:26:13 steve
* Constant propagate addresses through NetRamDq read ports.
*
* Revision 1.47.2.4 2005/09/11 02:50:51 steve
* Fix overly agressive constant propagation through MUX causing lost Z bits.
*

13
functor.cc
View File

@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: functor.cc,v 1.32 2004/10/04 01:10:53 steve Exp $"
#ident "$Id: functor.cc,v 1.32.2.1 2006/04/23 04:26:14 steve Exp $"
#endif
# include "config.h"
@ -79,6 +79,9 @@ void functor_t::lpm_mux(class Design*, class NetMux*)
{
}
void functor_t::lpm_ram_dq(class Design*, class NetRamDq*)
{
}
void NetScope::run_functor(Design*des, functor_t*fun)
{
@ -206,6 +209,11 @@ void NetMux::functor_node(Design*des, functor_t*fun)
fun->lpm_mux(des, this);
}
void NetRamDq::functor_node(Design*des, functor_t*fun)
{
fun->lpm_ram_dq(des, this);
}
proc_match_t::~proc_match_t()
{
}
@ -267,6 +275,9 @@ int proc_match_t::event_wait(NetEvWait*)
/*
* $Log: functor.cc,v $
* Revision 1.32.2.1 2006/04/23 04:26:14 steve
* Constant propagate addresses through NetRamDq read ports.
*
* Revision 1.32 2004/10/04 01:10:53 steve
* Clean up spurious trailing white space.
*

8
functor.h
View File

@ -19,7 +19,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: functor.h,v 1.20 2002/08/12 01:34:59 steve Exp $"
#ident "$Id: functor.h,v 1.20.2.1 2006/04/23 04:26:14 steve Exp $"
#endif
/*
@ -77,6 +77,9 @@ struct functor_t {
/* This method is called for each MUX. */
virtual void lpm_mux(class Design*des, class NetMux*);
/* This is called for eacm RamDq device. */
virtual void lpm_ram_dq(class Design*des, class NetRamDq*);
};
struct proc_match_t {
@ -92,6 +95,9 @@ struct proc_match_t {
/*
* $Log: functor.h,v $
* Revision 1.20.2.1 2006/04/23 04:26:14 steve
* Constant propagate addresses through NetRamDq read ports.
*
* Revision 1.20 2002/08/12 01:34:59 steve
* conditional ident string using autoconfig.
*

10
netlist.cc
View File

@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: netlist.cc,v 1.226.2.6 2006/04/16 19:26:38 steve Exp $"
#ident "$Id: netlist.cc,v 1.226.2.7 2006/04/23 04:26:14 steve Exp $"
#endif
# include "config.h"
@ -1625,6 +1625,11 @@ unsigned NetRamDq::size() const
return 0;
}
NetMemory* NetRamDq::mem()
{
return mem_;
}
const NetMemory* NetRamDq::mem() const
{
return mem_;
@ -2481,6 +2486,9 @@ const NetProc*NetTaskDef::proc() const
/*
* $Log: netlist.cc,v $
* Revision 1.226.2.7 2006/04/23 04:26:14 steve
* Constant propagate addresses through NetRamDq read ports.
*
* Revision 1.226.2.6 2006/04/16 19:26:38 steve
* Fix handling of exploded memories with partial or missing resets.
*

9
netlist.h
View File

@ -19,7 +19,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#ifdef HAVE_CVS_IDENT
#ident "$Id: netlist.h,v 1.321.2.16 2006/04/16 19:26:38 steve Exp $"
#ident "$Id: netlist.h,v 1.321.2.17 2006/04/23 04:26:14 steve Exp $"
#endif
/*
@ -995,6 +995,8 @@ class NetRamDq : public NetNode {
unsigned width() const;
unsigned awidth() const;
unsigned size() const;
NetMemory*mem();
const NetMemory*mem() const;
Link& pin_InClock();
@ -1025,6 +1027,8 @@ class NetRamDq : public NetNode {
// that are ports to the attached memory.
unsigned count_partners() const;
void functor_node(Design*des, functor_t*fun);
private:
NetMemory*mem_;
NetRamDq*next_;
@ -3524,6 +3528,9 @@ extern ostream& operator << (ostream&, NetNet::Type);
/*
* $Log: netlist.h,v $
* Revision 1.321.2.17 2006/04/23 04:26:14 steve
* Constant propagate addresses through NetRamDq read ports.
*
* Revision 1.321.2.16 2006/04/16 19:26:38 steve
* Fix handling of exploded memories with partial or missing resets.
*