iopadmap: move \init attributes from outpad output to its input

passes/techmap/iopadmap.cc

@@ -408,18 +408,35 @@ struct IopadmapPass : public Pass {
 				RTLIL::Wire *wire = it.first;
 				RTLIL::Wire *new_wire = module->addWire(NEW_ID, wire);
 				module->swap_names(new_wire, wire);
-				wire->attributes.clear();
 				for (int i = 0; i < wire->width; i++)
 				{
 					SigBit wire_bit(wire, i);
 					if (!it.second.count(i)) {
-						if (wire->port_output)
+						if (wire->port_output) {
 							module->connect(SigSpec(new_wire, i), SigSpec(wire, i));
-						else
+							wire->attributes.clear();
+						}
+						else {
 							module->connect(SigSpec(wire, i), SigSpec(new_wire, i));
+							wire->attributes.clear();
+
+						}
 					} else {
 						auto &new_conn = it.second.at(i);
 						new_conn.first->setPort(new_conn.second, RTLIL::SigSpec(new_wire, i));
+
+						// For cell outputs, move \init attributes from old wire to new wire
+						if (new_conn.first->output(new_conn.second)) {
+							auto it = wire->attributes.find(ID(init));
+							if (it != wire->attributes.end()) {
+								for (auto it2 = wire->attributes.begin(); it2 != wire->attributes.end(); )
+									if (it == it2)
+										++it2;
+									else
+										it2 = wire->attributes.erase(it2);
+								new_wire->attributes.erase(ID(init));
+							}
+						}
 					}
 				}
 

tests/techmap/iopadmap.ys

@@ -120,3 +120,40 @@ select -assert-count 1 g/t:iobuf
 select -assert-count 1 h/t:ibuf
 select -assert-count 1 h/t:iobuf
 select -assert-count 1 h/t:obuf
+
+
+# Check that \init attributes get moved from output buffer
+#   to buffer input
+design -reset
+read_verilog << EOT
+module obuf (input i, (* iopad_external_pin *) output o); endmodule
+module obuft (input i, input oe, (* iopad_external_pin *) output o); endmodule
+module iobuf (input i, input oe, output o, (* iopad_external_pin *) inout io); endmodule
+module sub(input i, output o); endmodule
+
+module a(input i, (* init=1'b1 *) output o);
+sub s(.i(i), .o(o));
+endmodule
+
+module b(input i, oe, output o);
+(* init=1'b1 *) wire w;
+sub s(.i(i), .o(w));
+assign o = oe ? w : 1'bz;
+endmodule
+
+module c(input i, oe, inout io);
+(* init=1'b1 *) wire w;
+sub s(.i(i), .o(w));
+assign io = oe ? w : 1'bz;
+endmodule
+EOT
+opt_clean
+tribuf
+simplemap
+iopadmap -bits -outpad obuf i:o -toutpad obuft oe:i:o -tinoutpad iobuf oe:o:i:io
+select -assert-count 1 a/c:s %co a/a:init=1'1 %i
+select -assert-count 1 a/a:init=1'1
+select -assert-count 1 b/c:s %co b/a:init=1'1 %i
+select -assert-count 1 b/a:init=1'1
+select -assert-count 1 c/c:s %co c/a:init=1'1 %i
+select -assert-count 1 c/a:init=1'1