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Fix handling of ternary-to-bufif0 constant propagation.

This commit is contained in:
steve 2006-05-24 04:32:57 +00:00
parent 019d61f633
commit 857b3e15b6
1 changed files with 48 additions and 53 deletions
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101
cprop.cc
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@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/ */
#ifdef HAVE_CVS_IDENT #ifdef HAVE_CVS_IDENT
#ident "$Id: cprop.cc,v 1.54 2005/07/15 19:22:52 steve Exp $" #ident "$Id: cprop.cc,v 1.55 2006/05/24 04:32:57 steve Exp $"
#endif #endif
# include "config.h" # include "config.h"
@ -738,6 +738,48 @@ v }
} }
} }
static void replace_with_bufif(Design*des, NetMux*obj, NetLogic::TYPE type)
{
NetScope*scope = obj->scope();
NetLogic*tmp = new NetLogic(obj->scope(),
scope->local_symbol(),
3, type, obj->width());
des->add_node(tmp);
connect(obj->pin_Result(), tmp->pin(0));
connect(obj->pin_Data(type==NetLogic::BUFIF0? 0 : 1), tmp->pin(1));
if (obj->width() == 1) {
/* Special case that the expression is 1 bit
wide. Connect the select directly to the enable. */
connect(obj->pin_Sel(), tmp->pin(2));
} else {
/* General case that the expression is arbitrarily
wide. Replicate the enable signal (which we
assume is 1 bit wide) to match the expression,
and connect the enable vector to the enable
input of the gate. */
NetReplicate*rtmp = new NetReplicate(scope,
scope->local_symbol(),
obj->width(),
obj->width());
des->add_node(rtmp);
connect(obj->pin_Sel(), rtmp->pin(1));
connect(tmp->pin(2), rtmp->pin(0));
NetNet*rsig = new NetNet(scope, scope->local_symbol(),
NetNet::WIRE, obj->width());
rsig->local_flag(true);
rsig->data_type(IVL_VT_LOGIC);
connect(tmp->pin(2), rsig->pin(0));
}
delete obj;
}
/* /*
* This detects the case where the mux selects between a value and * This detects the case where the mux selects between a value and
* Vz. In this case, replace the device with a bufif with the sel * Vz. In this case, replace the device with a bufif with the sel
@ -764,47 +806,8 @@ void cprop_functor::lpm_mux(Design*des, NetMux*obj)
} }
if (flag) { if (flag) {
NetScope*scope = obj->scope(); replace_with_bufif(des, obj, NetLogic::BUFIF1);
NetLogic*tmp = new NetLogic(obj->scope(),
scope->local_symbol(),
3, NetLogic::BUFIF1, obj->width());
des->add_node(tmp);
connect(obj->pin_Result(), tmp->pin(0));
connect(obj->pin_Data(1), tmp->pin(1));
if (obj->width() == 1) {
/* Special case that the expression is 1 bit
wide. Connect the select directly to the
enable. */
connect(obj->pin_Sel(), tmp->pin(2));
} else {
/* General case that the expression is arbitrarily
wide. Replicate the enable signal (which we
assume is 1 bit wide) to match the expression,
and connect the enable vector to the enable
input of the gate. */
NetReplicate*rtmp = new NetReplicate(scope,
scope->local_symbol(),
obj->width(),
obj->width());
des->add_node(rtmp);
connect(obj->pin_Sel(), rtmp->pin(1));
connect(tmp->pin(2), rtmp->pin(0));
NetNet*rsig = new NetNet(scope, scope->local_symbol(),
NetNet::WIRE, obj->width());
rsig->local_flag(true);
rsig->data_type(IVL_VT_LOGIC);
connect(tmp->pin(2), rsig->pin(0));
}
count += 1; count += 1;
delete obj;
return; return;
} }
@ -821,19 +824,8 @@ void cprop_functor::lpm_mux(Design*des, NetMux*obj)
} }
if (flag) { if (flag) {
NetScope*scope = obj->scope(); replace_with_bufif(des, obj, NetLogic::BUFIF0);
NetLogic*tmp = new NetLogic(obj->scope(),
scope->local_symbol(),
3, NetLogic::BUFIF0, obj->width());
connect(obj->pin_Result(), tmp->pin(0));
connect(obj->pin_Data(0), tmp->pin(1));
connect(obj->pin_Sel(), tmp->pin(2));
des->add_node(tmp);
count += 1; count += 1;
delete obj;
return; return;
} }
} }
@ -956,6 +948,9 @@ void cprop(Design*des)
/* /*
* $Log: cprop.cc,v $ * $Log: cprop.cc,v $
* Revision 1.55 2006/05/24 04:32:57 steve
* Fix handling of ternary-to-bufif0 constant propagation.
*
* Revision 1.54 2005/07/15 19:22:52 steve * Revision 1.54 2005/07/15 19:22:52 steve
* bufif enable is LOGIC. * bufif enable is LOGIC.
* *