Add $bmux and $demux cells.

2 files changed, 53 insertions, 1 deletions

diff --git a/backends/cxxrtl/cxxrtl.h b/backends/cxxrtl/cxxrtl.h
index 3e1357498..b4ffa87cd 100644
--- a/backends/cxxrtl/cxxrtl.h
+++ b/backends/cxxrtl/cxxrtl.h
@@ -457,6 +457,42 @@ struct value : public expr_base<value<Bits>> {
 		return shr<AmountBits, /*Signed=*/true>(amount);
 	}
 
+	template<size_t ResultBits, size_t SelBits>
+	value<ResultBits> bmux(const value<SelBits> &sel) const {
+		static_assert(ResultBits << SelBits == Bits, "invalid sizes used in bmux()");
+		size_t amount = sel.data[0] * ResultBits;
+		size_t shift_chunks = amount / chunk::bits;
+		size_t shift_bits   = amount % chunk::bits;
+		value<ResultBits> result;
+		chunk::type carry = 0;
+		if (ResultBits % chunk::bits + shift_bits > chunk::bits)
+			carry = data[result.chunks + shift_chunks] << (chunk::bits - shift_bits);
+		for (size_t n = 0; n < result.chunks; n++) {
+			result.data[result.chunks - 1 - n] = carry | (data[result.chunks + shift_chunks - 1 - n] >> shift_bits);
+			carry = (shift_bits == 0) ? 0
+				: data[result.chunks + shift_chunks - 1 - n] << (chunk::bits - shift_bits);
+		}
+		return result;
+	}
+
+	template<size_t ResultBits, size_t SelBits>
+	value<ResultBits> demux(const value<SelBits> &sel) const {
+		static_assert(Bits << SelBits == ResultBits, "invalid sizes used in demux()");
+		size_t amount = sel.data[0] * Bits;
+		size_t shift_chunks = amount / chunk::bits;
+		size_t shift_bits   = amount % chunk::bits;
+		value<ResultBits> result;
+		chunk::type carry = 0;
+		for (size_t n = 0; n < chunks; n++) {
+			result.data[shift_chunks + n] = (data[n] << shift_bits) | carry;
+			carry = (shift_bits == 0) ? 0
+				: data[n] >> (chunk::bits - shift_bits);
+		}
+		if (Bits % chunk::bits + shift_bits > chunk::bits)
+			result.data[shift_chunks + chunks] = carry;
+		return result;
+	}
+
 	size_t ctpop() const {
 		size_t count = 0;
 		for (size_t n = 0; n < chunks; n++) {
diff --git a/backends/cxxrtl/cxxrtl_backend.cc b/backends/cxxrtl/cxxrtl_backend.cc
index 7a336f8c1..404755b1e 100644
--- a/backends/cxxrtl/cxxrtl_backend.cc
+++ b/backends/cxxrtl/cxxrtl_backend.cc
@@ -198,7 +198,7 @@ bool is_extending_cell(RTLIL::IdString type)
 bool is_inlinable_cell(RTLIL::IdString type)
 {
 	return is_unary_cell(type) || is_binary_cell(type) || type.in(
-		ID($mux), ID($concat), ID($slice), ID($pmux));
+		ID($mux), ID($concat), ID($slice), ID($pmux), ID($bmux), ID($demux));
 }
 
 bool is_ff_cell(RTLIL::IdString type)
@@ -1154,6 +1154,22 @@ struct CxxrtlWorker {
 			for (int part = 0; part < s_width; part++) {
 				f << ")";
 			}
+		// Big muxes
+		} else if (cell->type == ID($bmux)) {
+			dump_sigspec_rhs(cell->getPort(ID::A), for_debug);
+			f << ".bmux<";
+			f << cell->getParam(ID::WIDTH).as_int();
+			f << ">(";
+			dump_sigspec_rhs(cell->getPort(ID::S), for_debug);
+			f << ").val()";
+		// Demuxes
+		} else if (cell->type == ID($demux)) {
+			dump_sigspec_rhs(cell->getPort(ID::A), for_debug);
+			f << ".demux<";
+			f << GetSize(cell->getPort(ID::Y));
+			f << ">(";
+			dump_sigspec_rhs(cell->getPort(ID::S), for_debug);
+			f << ").val()";
 		// Concats
 		} else if (cell->type == ID($concat)) {
 			dump_sigspec_rhs(cell->getPort(ID::B), for_debug);