diff --git a/tgt-vvp/vvp_scope.c b/tgt-vvp/vvp_scope.c index ccb7f2860..ea4ba8041 100644 --- a/tgt-vvp/vvp_scope.c +++ b/tgt-vvp/vvp_scope.c @@ -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. *