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Generate code for identity comparators.

This commit is contained in:
steve 2001-09-14 04:15:46 +00:00
parent 5976e7078c
commit f2068e83d4
1 changed files with 107 additions and 33 deletions
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140
tgt-vvp/vvp_scope.c
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@ -17,7 +17,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#if !defined(WINNT)
#ident "$Id: vvp_scope.c,v 1.45 2001/08/10 00:40:45 steve Exp $"
#ident "$Id: vvp_scope.c,v 1.46 2001/09/14 04:15:46 steve Exp $"
#endif
# include "vvp_priv.h"
@ -239,6 +239,8 @@ static const char* draw_net_input_drive(ivl_nexus_t nex, ivl_nexus_ptr_t nptr)
case IVL_LPM_CMP_GE:
case IVL_LPM_CMP_GT:
case IVL_LPM_CMP_EQ:
case IVL_LPM_CMP_NE:
if (ivl_lpm_q(lpm, 0) == nex) {
sprintf(result, "L_%s", vvp_mangle_id(ivl_lpm_name(lpm)));
return result;
@ -275,7 +277,7 @@ static const char* draw_net_input(ivl_nexus_t nex)
/* If this nexus already has a label, then its input is
already figured out. Just return the existing label. */
const char*nex_private = (const char*)ivl_nexus_get_private(nex);
char*nex_private = (char*)ivl_nexus_get_private(nex);
if (nex_private)
return nex_private;
@ -365,42 +367,11 @@ static const char* draw_net_input(ivl_nexus_t nex)
*/
static void draw_input_from_net(ivl_nexus_t nex)
{
#if 0
unsigned idx;
ivl_signal_t sig = 0;
unsigned sig_pin = 0;
for (idx = 0 ; idx < ivl_nexus_ptrs(nex) ; idx += 1) {
ivl_nexus_ptr_t ptr = ivl_nexus_ptr(nex, idx);
ivl_signal_t tmp = ivl_nexus_ptr_sig(ptr);
if (tmp == 0)
continue;
if (sig == 0) {
sig = tmp;
sig_pin = ivl_nexus_ptr_pin(ptr);
continue;
}
if (strcmp(ivl_signal_name(tmp),ivl_signal_name(sig)) < 0) {
sig = tmp;
sig_pin = ivl_nexus_ptr_pin(ptr);
continue;
}
}
assert(sig);
fprintf(vvp_out, "V_%s[%u]",
vvp_mangle_id(ivl_signal_name(sig)), sig_pin);
#else
const char*nex_private = (const char*)ivl_nexus_get_private(nex);
if (nex_private == 0)
nex_private = draw_net_input(nex);
assert(nex_private);
fprintf(vvp_out, "%s", nex_private);
#endif
}
/*
@ -957,6 +928,101 @@ static void draw_lpm_cmp(ivl_lpm_t net)
fprintf(vvp_out, ";\n");
}
/*
* Draw == and != gates. This is done as XNOR functors to compare each
* pair of bits. The result is combined with a wide and, or a NAND if
* this is a NE.
*/
static void draw_lpm_eq(ivl_lpm_t net)
{
unsigned width = ivl_lpm_width(net);
unsigned idx;
const char*and = ivl_lpm_type(net) == IVL_LPM_CMP_NE? "NAND" : "AND";
ivl_nexus_t nex;
for (idx = 0 ; idx < width ; idx += 1) {
fprintf(vvp_out, "L_%s/L0C%u .functor XNOR, ",
vvp_mangle_id(ivl_lpm_name(net)), idx);
nex = ivl_lpm_data(net, idx);
draw_input_from_net(nex);
fprintf(vvp_out, ", ");
nex = ivl_lpm_datab(net, idx);
draw_input_from_net(nex);
fprintf(vvp_out, ", C<0>, C<0>;\n");
}
if (width <= 4) {
fprintf(vvp_out, "L_%s .functor %s",
vvp_mangle_id(ivl_lpm_name(net)), and);
for (idx = 0 ; idx < width ; idx += 1)
fprintf(vvp_out, ", L_%s/L0C%u",
vvp_mangle_id(ivl_lpm_name(net)), idx);
for (idx = width ; idx < 4 ; idx += 1)
fprintf(vvp_out, ", C<1>");
fprintf(vvp_out, ";\n");
} else {
unsigned lwidth = width;
unsigned level = 1;
unsigned cnt;
unsigned bit;
unsigned first;
unsigned last;
cnt = (lwidth + 3) / 4;
while (cnt > 1) {
for (idx = 0 ; idx < cnt ; idx += 1) {
first = idx*4;
last = first + 4;
if (last > lwidth)
last = lwidth;
fprintf(vvp_out, "L_%s/L%uC%u .functor AND",
vvp_mangle_id(ivl_lpm_name(net)),
level, idx);
for (bit = first ; bit < last ; bit += 1)
fprintf(vvp_out, ", L_%s/L%uC%u",
vvp_mangle_id(ivl_lpm_name(net)),
level-1, bit);
for (bit = last ; bit < (idx*4+4) ; bit += 1)
fprintf(vvp_out, ", C<1>");
fprintf(vvp_out, ";\n");
}
lwidth = cnt;
level += 1;
cnt = (lwidth + 3) / 4;
}
fprintf(vvp_out, "L_%s .functor %s",
vvp_mangle_id(ivl_lpm_name(net)), and);
for (idx = 0 ; idx < lwidth ; idx += 1)
fprintf(vvp_out, ", L_%s/L%uC%u",
vvp_mangle_id(ivl_lpm_name(net)),
level-1, idx);
for (idx = lwidth ; idx < 4 ; idx += 1)
fprintf(vvp_out, ", C<1>");
fprintf(vvp_out, ";\n");
}
}
static void draw_lpm_mux(ivl_lpm_t net)
{
ivl_nexus_t s;
@ -1025,6 +1091,11 @@ static void draw_lpm_in_scope(ivl_lpm_t net)
draw_lpm_add(net);
return;
case IVL_LPM_CMP_EQ:
case IVL_LPM_CMP_NE:
draw_lpm_eq(net);
return;
case IVL_LPM_CMP_GE:
case IVL_LPM_CMP_GT:
draw_lpm_cmp(net);
@ -1128,6 +1199,9 @@ int draw_scope(ivl_scope_t net, ivl_scope_t parent)
/*
* $Log: vvp_scope.c,v $
* Revision 1.46 2001/09/14 04:15:46 steve
* Generate code for identity comparators.
*
* Revision 1.45 2001/08/10 00:40:45 steve
* tgt-vvp generates code that skips nets as inputs.
*