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pack output DFF together with XLUT

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This commit is contained in:
Miodrag Milanovic 2024-08-08 16:24:26 +02:00
parent 73958db6e5
commit b9c834dc27
1 changed files with 15 additions and 5 deletions
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20
himbaechel/uarch/ng-ultra/pack.cc
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@ -369,6 +369,10 @@ void NgUltraPacker::pack_xluts(void)
bind_attr_loc(&ci, &ci.attrs);
ci.cluster = ci.name;
xlut_used++;
NetInfo *o = ci.getPort(id_O);
CellInfo *orig_dff = o ? net_only_drives(ctx, o, is_dff, id_I, true) : nullptr;
for (int i=0;i<4;i++) {
ci.constr_children.push_back(lut[i]);
lut[i]->cluster = ci.cluster;
@ -378,8 +382,16 @@ void NgUltraPacker::pack_xluts(void)
lut[i]->params[id_lut_used] = Property(1,1);
NetInfo *net = lut[i]->getPort(id_LO);
if (net->users.entries()!=2) {
lut[i]->timing_index = ctx->get_cell_timing_idx(ctx->id("BEYOND_FE_LUT"));
lut_only++;
if (orig_dff && net->users.entries()==1) {
// we place DFF on XLUT output on unused DFF
dff_to_fe(orig_dff, lut[i], false);
packed_cells.insert(orig_dff->name);
lut_and_ff++;
orig_dff = nullptr;
} else {
lut[i]->timing_index = ctx->get_cell_timing_idx(ctx->id("BEYOND_FE_LUT"));
lut_only++;
}
} else {
CellInfo *dff = (*net->users.begin()).cell;
if (dff->type!=id_NX_DFF)
@ -392,9 +404,7 @@ void NgUltraPacker::pack_xluts(void)
lut[i]->timing_index = ctx->get_cell_timing_idx(ctx->id("BEYOND_FE_LUT"));
lut_only++;
}
}
}
}
}
if (xlut_used)