diff --git a/passes/techmap/booth.cc b/passes/techmap/booth.cc index 64a924e4f..df0f82ec2 100644 --- a/passes/techmap/booth.cc +++ b/passes/techmap/booth.cc @@ -225,108 +225,92 @@ struct BoothPassWorker { void run() { for (auto cell : module->selected_cells()) { - if (cell->type.in(ID($mul))) { - RTLIL::SigSpec A = sigmap(cell->getPort(ID::A)); - RTLIL::SigSpec B = sigmap(cell->getPort(ID::B)); - RTLIL::SigSpec Y = sigmap(cell->getPort(ID::Y)); - if (GetSize(A) >= 4 && GetSize(B) >= 4 && GetSize(Y) >= 8 && - ((cell->getParam(ID::A_SIGNED).as_bool() && cell->getParam(ID::B_SIGNED).as_bool()) || - (!cell->getParam(ID::A_SIGNED).as_bool() && !cell->getParam(ID::B_SIGNED).as_bool()))) { - bool is_signed = false; - if (cell->getParam(ID::A_SIGNED).as_bool()) { - log(" By passing macc inferencing for signed multiplier -- generating booth\n"); - is_signed = true; - } else - log(" By passing macc inferencing for unsigned multiplier -- generating booth\n"); + if (cell->type != ID($mul)) + continue; - int x_sz = GetSize(A); - int y_sz = GetSize(B); - int z_sz = GetSize(Y); + SigSpec A = cell->getPort(ID::A); + SigSpec B = cell->getPort(ID::B); + SigSpec Y = cell->getPort(ID::Y); + int x_sz = GetSize(A), y_sz = GetSize(B), z_sz = GetSize(Y); - // To simplify the generator size the arguments - // to be the same. Then allow logic synthesis to - // clean things up. Size to biggest + if (x_sz < 4 || y_sz < 4 || z_sz < 8) { + log_debug("Not mapping cell %s sized at %dx%x, %x: size below threshold\n", + log_id(cell), x_sz, y_sz, z_sz); + continue; + } - int x_sz_revised = x_sz; - int y_sz_revised = y_sz; + log_assert(cell->getParam(ID::A_SIGNED).as_bool() == cell->getParam(ID::B_SIGNED).as_bool()); + bool is_signed = cell->getParam(ID::A_SIGNED).as_bool(); - if (x_sz != y_sz) { - if (x_sz < y_sz) { - if (y_sz % 2 != 0) { - x_sz_revised = y_sz + 1; - y_sz_revised = y_sz + 1; - } else - x_sz_revised = y_sz; + log("Mapping cell %s to %s Booth multiplier\n", log_id(cell), is_signed ? "signed" : "unsigned"); - } else { - if (x_sz % 2 != 0) { - y_sz_revised = x_sz + 1; - x_sz_revised = x_sz + 1; - } else - y_sz_revised = x_sz; - } + // To simplify the generator size the arguments + // to be the same. Then allow logic synthesis to + // clean things up. Size to biggest + + int x_sz_revised = x_sz; + int y_sz_revised = y_sz; + + if (x_sz != y_sz) { + if (x_sz < y_sz) { + if (y_sz % 2 != 0) { + x_sz_revised = y_sz + 1; + y_sz_revised = y_sz + 1; } else { - if (x_sz % 2 != 0) { - y_sz_revised = y_sz + 1; - x_sz_revised = x_sz + 1; - } + x_sz_revised = y_sz; + } + } else { + if (x_sz % 2 != 0) { + y_sz_revised = x_sz + 1; + x_sz_revised = x_sz + 1; + } else { + y_sz_revised = x_sz; } - - log_assert((x_sz_revised == y_sz_revised) && (x_sz_revised % 2 == 0) && (y_sz_revised % 2 == 0)); - - Wire *expanded_A = module->addWire(NEW_ID, x_sz_revised); - Wire *expanded_B = module->addWire(NEW_ID, y_sz_revised); - - std::string buf_name = "expand_a_buf_"; - auto buf = module->addCell(new_id(buf_name, __LINE__, ""), ID($pos)); - buf->setParam(ID::A_WIDTH, x_sz); - buf->setParam(ID::Y_WIDTH, x_sz_revised); - buf->setPort(ID::A, SigSpec(A)); - buf->setParam(ID::A_SIGNED, is_signed ? true : false); - buf->setPort(ID::Y, SigSpec(expanded_A)); - - buf_name = "expand_b_buf_"; - buf = module->addCell(new_id(buf_name, __LINE__, ""), ID($pos)); - buf->setPort(ID::A, SigSpec(B)); - buf->setParam(ID::A_WIDTH, y_sz); - buf->setParam(ID::Y_WIDTH, y_sz_revised); - buf->setParam(ID::A_SIGNED, is_signed ? true : false); - buf->setPort(ID::Y, SigSpec(expanded_B)); - - // Make sure output domain is big enough to take - // all combinations. - // Later logic synthesis will kill unused - // portions of the output domain. - - unsigned required_op_size = x_sz_revised + y_sz_revised; - Wire *expanded_Y = module->addWire(NEW_ID, required_op_size); - // now connect the expanded_Y with a tap to fill out sig Spec Y - buf_name = "reducer_buf_"; - buf = module->addCell(new_id(buf_name, __LINE__, ""), ID($pos)); - buf->setPort(ID::A, expanded_Y); - buf->setParam(ID::A_WIDTH, required_op_size); - buf->setParam(ID::Y_WIDTH, z_sz); // The real user width - buf->setParam(ID::A_SIGNED, is_signed ? true : false); - // wire in output Y - buf->setPort(ID::Y, SigSpec(Y)); - - if (is_signed == false) /* unsigned multiplier */ - CreateBoothUMult(module, - expanded_A, // multiplicand - expanded_B, // multiplier(scanned) - expanded_Y // result - ); - else /*signed multiplier */ - CreateBoothSMult(module, - expanded_A, // multiplicand - expanded_B, // multiplier(scanned) - expanded_Y // result (sized) - ); - module->remove(cell); - booth_counter++; - continue; + } + } else { + if (x_sz % 2 != 0) { + y_sz_revised = y_sz + 1; + x_sz_revised = x_sz + 1; } } + + log_assert((x_sz_revised == y_sz_revised) && (x_sz_revised % 2 == 0) && (y_sz_revised % 2 == 0)); + + + A.extend_u0(x_sz_revised, is_signed); + B.extend_u0(y_sz_revised, is_signed); + + // Make sure output domain is big enough to take + // all combinations. + // Later logic synthesis will kill unused + // portions of the output domain. + + int required_op_size = x_sz_revised + y_sz_revised; + + if (required_op_size != z_sz) { + SigSpec expanded_Y = module->addWire(NEW_ID, required_op_size); + SigSpec Y_driver = expanded_Y; + Y_driver.extend_u0(Y.size(), is_signed); + module->connect(Y, Y_driver); + Y = expanded_Y; + } + log_assert(GetSize(Y) == required_op_size); + + if (!is_signed) /* unsigned multiplier */ + CreateBoothUMult(module, + A, // multiplicand + B, // multiplier(scanned) + Y // result + ); + else /* signed multiplier */ + CreateBoothSMult(module, + A, // multiplicand + B, // multiplier(scanned) + Y // result (sized) + ); + + module->remove(cell); + booth_counter++; } }