Fix abc9 with (* keep *) wires

diff --git a/backends/aiger/xaiger.cc b/backends/aiger/xaiger.cc
index d6438a297771ee32c47751a07bd81c0a15eef060..504a660860e28530b07e4bedb3f8a403de34a68c 100644 (file)
--- a/backends/aiger/xaiger.cc
+++ b/backends/aiger/xaiger.cc
@@ -133,6 +133,8 @@ struct XAigerWriter
                                                init_map[initsig[i]] = initval[i] == State::S1;
                        }
 
+                       bool keep = wire->attributes.count("\\keep");
+
                        for (int i = 0; i < GetSize(wire); i++)
                        {
                                SigBit wirebit(wire, i);
@@ -151,8 +153,10 @@ struct XAigerWriter
 
                                if (wire->port_input)
                                        input_bits.insert(bit);
+                               else if (keep)
+                                       input_bits.insert(wirebit);
 
-                               if (wire->port_output) {
+                               if (wire->port_output || keep) {
                                        if (bit != wirebit)
                                                alias_map[wirebit] = bit;
                                        output_bits.insert(wirebit);
@@ -338,10 +342,12 @@ struct XAigerWriter
 
                for (auto bit : input_bits) {
                        RTLIL::Wire *wire = bit.wire;
-                       // If encountering an inout port, then create a new wire with $inout.out
-                       // suffix, make it a PO driven by the existing inout, and inherit existing
-                       // inout's drivers
-                       if (wire->port_input && wire->port_output && !undriven_bits.count(bit)) {
+                       // If encountering an inout port, or a keep-ed wire, then create a new wire
+                       // with $inout.out suffix, make it a PO driven by the existing inout, and
+                       // inherit existing inout's drivers
+                       if ((wire->port_input && wire->port_output && !undriven_bits.count(bit))
+                                       || wire->attributes.count("\\keep")) {
+                               log_assert(input_bits.count(bit) && output_bits.count(bit));
                                RTLIL::Wire *new_wire = module->wire(wire->name.str() + "$inout.out");
                                if (!new_wire)
                                        new_wire = module->addWire(wire->name.str() + "$inout.out", GetSize(wire));
@@ -354,7 +360,9 @@ struct XAigerWriter
                                else if (alias_map.count(bit))
                                        alias_map[new_bit] = alias_map.at(bit);
                                else
+                                       //log_abort();
                                        alias_map[new_bit] = bit;
+                               output_bits.erase(bit);
                                output_bits.insert(new_bit);
                        }
                }
@@ -750,7 +758,7 @@ struct XAigerWriter
                        {
                                RTLIL::SigBit b(wire, i);
                                if (input_bits.count(b)) {
-                                       int a = aig_map.at(sig[i]);
+                                       int a = aig_map.at(b);
                                        log_assert((a & 1) == 0);
                                        input_lines[a] += stringf("input %d %d %s\n", (a >> 1)-1, i, log_id(wire));
                                }

diff --git a/tests/simple_abc9/abc9.v b/tests/simple_abc9/abc9.v
index eca340693b544b4c728194a8ee3ecc58d71015ed..f37d975ff74aa0101bfe17deb05c5f858f50f727 100644 (file)
--- a/tests/simple_abc9/abc9.v
+++ b/tests/simple_abc9/abc9.v
@@ -104,3 +104,41 @@ always @(io or oe)
 assign io[3:0] = oe ? ~latch[3:0] : 4'bz;
 assign io[7:4] = !oe ? {latch[4], latch[7:3]} : 4'bz;
 endmodule
+
+module abc9_test015(input a, output b, input c);
+assign b = ~a;
+(* keep *) wire d;
+assign d = ~c;
+endmodule
+
+module abc9_test016(input a, output b);
+assign b = ~a;
+(* keep *) reg c;
+always @* c <= ~a;
+endmodule
+
+module abc9_test017(input a, output b);
+assign b = ~a;
+(* keep *) reg c;
+always @* c = b;
+endmodule
+
+module abc9_test018(input a, output b, output c);
+assign b = ~a;
+(* keep *) wire [1:0] d;
+assign c = &d;
+endmodule
+
+module abc9_test019(input a, output b);
+assign b = ~a;
+(* keep *) reg [1:0] c;
+reg d;
+always @* d <= &c;
+endmodule
+
+module abc9_test020(input a, output b);
+assign b = ~a;
+(* keep *) reg [1:0] c;
+(* keep *) reg d;
+always @* d <= &c;
+endmodule