diff options
Diffstat (limited to 'passes/techmap/shregmap.cc')
| -rw-r--r-- | passes/techmap/shregmap.cc | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/passes/techmap/shregmap.cc b/passes/techmap/shregmap.cc index a541b33be..004ab1eb9 100644 --- a/passes/techmap/shregmap.cc +++ b/passes/techmap/shregmap.cc @@ -178,7 +178,17 @@ struct ShregmapTechXilinx7 : ShregmapTech // Only map if $shiftx exclusively covers the shift register if (shiftx->type == "$shiftx") { - if (GetSize(taps) != shiftx->getParam("\\A_WIDTH").as_int()) + if (GetSize(taps) > shiftx->getParam("\\A_WIDTH").as_int()) + return false; + // Due to padding the most significant bits of A may be 1'bx, + // and if so, discount them + if (GetSize(taps) < shiftx->getParam("\\A_WIDTH").as_int()) { + const SigSpec A = shiftx->getPort("\\A"); + const int A_width = shiftx->getParam("\\A_WIDTH").as_int(); + for (int i = GetSize(taps); i < A_width; ++i) + if (A[i] != RTLIL::Sx) return false; + } + else if (GetSize(taps) != shiftx->getParam("\\A_WIDTH").as_int()) return false; } else if (shiftx->type == "$mux") { @@ -283,10 +293,22 @@ struct ShregmapWorker if (opts.init || sigbit_init.count(q_bit) == 0) { - if (sigbit_chain_next.count(d_bit)) { + auto r = sigbit_chain_next.insert(std::make_pair(d_bit, cell)); + if (!r.second) { + // Insertion not successful means that d_bit is already + // connected to another register, thus mark it as a + // non chain user ... sigbit_with_non_chain_users.insert(d_bit); - } else - sigbit_chain_next[d_bit] = cell; + // ... and clone d_bit into another wire, and use that + // wire as a different key in the d_bit-to-cell dictionary + // so that it can be identified as another chain + // (omitting this common flop) + // Link: https://github.com/YosysHQ/yosys/pull/1085 + Wire *wire = module->addWire(NEW_ID); + module->connect(wire, d_bit); + sigmap.add(wire, d_bit); + sigbit_chain_next.insert(std::make_pair(wire, cell)); + } sigbit_chain_prev[q_bit] = cell; continue; @@ -595,6 +617,11 @@ struct ShregmapPass : public Pass { log("\n"); log(" -tech greenpak4\n"); log(" map to greenpak4 shift registers.\n"); + log(" this option also implies -clkpol pos -zinit\n"); + log("\n"); + log(" -tech xilinx\n"); + log(" map to xilinx dynamic-length shift registers.\n"); + log(" this option also implies -params -init\n"); log("\n"); } void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE |