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Fix FIRRTL to Verilog process instance subfield assignment.

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Don't emit subfield assignments: bits(x, y, z) <= ... - but instead, add them to the reverse-wire-map where they'll be treated at the end of the module.
Enable tests which were disabled due to incorrect treatment of subfields.
Assume the `$firrtl2verilog` variable contains any additional switches to control verilog generation (i.e. `--no-dedup -X mverilog`)
This commit is contained in:
Jim Lawson 2019-02-25 16:18:13 -08:00
parent c258b99040
commit 171c425cf9
4 changed files with 21 additions and 11 deletions
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28
backends/firrtl/firrtl.cc
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@ -169,7 +169,6 @@ struct FirrtlWorker
return *str == '\\' ? str + 1 : str;
}
std::string cellname(RTLIL::Cell *cell)
{
return fid(cell->name).c_str();
@ -219,29 +218,42 @@ struct FirrtlWorker
if (it->second.size() > 0) {
const SigSpec &secondSig = it->second;
const std::string firstName = cell_name + "." + make_id(it->first);
const std::string secondName = make_expr(secondSig);
const std::string secondExpr = make_expr(secondSig);
// Find the direction for this port.
FDirection dir = getPortFDirection(it->first, instModule);
std::string source, sink;
std::string sourceExpr, sinkExpr;
const SigSpec *sinkSig = nullptr;
switch (dir) {
case FD_INOUT:
log_warning("Instance port connection %s.%s is INOUT; treating as OUT\n", cell_type.c_str(), log_signal(it->second));
case FD_OUT:
source = firstName;
sink = secondName;
sourceExpr = firstName;
sinkExpr = secondExpr;
sinkSig = &secondSig;
break;
case FD_NODIRECTION:
log_warning("Instance port connection %s.%s is NODIRECTION; treating as IN\n", cell_type.c_str(), log_signal(it->second));
/* FALL_THROUGH */
case FD_IN:
source = secondName;
sink = firstName;
sourceExpr = secondExpr;
sinkExpr = firstName;
break;
default:
log_error("Instance port %s.%s unrecognized connection direction 0x%x !\n", cell_type.c_str(), log_signal(it->second), dir);
break;
}
wire_exprs.push_back(stringf("\n%s%s <= %s", indent.c_str(), sink.c_str(), source.c_str()));
// Check for subfield assignment.
std::string bitsString = "bits(";
if (sinkExpr.substr(0, bitsString.length()) == bitsString ) {
if (sinkSig == nullptr)
log_error("Unknown subfield %s.%s\n", cell_type.c_str(), sinkExpr.c_str());
// Don't generate the assignment here.
// Add the source and sink to the "reverse_wire_map" and we'll output the assignment
// as part of the coalesced subfield assignments for this wire.
register_reverse_wire_map(sourceExpr, *sinkSig);
} else {
wire_exprs.push_back(stringf("\n%s%s <= %s", indent.c_str(), sinkExpr.c_str(), sourceExpr.c_str()));
}
}
}
wire_exprs.push_back(stringf("\n"));