aboutsummaryrefslogtreecommitdiffstats
path: root/backends/firrtl/firrtl.cc
diff options
context:
space:
mode:
Diffstat (limited to 'backends/firrtl/firrtl.cc')
-rw-r--r--backends/firrtl/firrtl.cc282
1 files changed, 239 insertions, 43 deletions
diff --git a/backends/firrtl/firrtl.cc b/backends/firrtl/firrtl.cc
index 0917ecba6..1c7a7351f 100644
--- a/backends/firrtl/firrtl.cc
+++ b/backends/firrtl/firrtl.cc
@@ -106,6 +106,125 @@ struct FirrtlWorker
RTLIL::Design *design;
std::string indent;
+ // Define read/write ports and memories.
+ // We'll collect their definitions and emit the corresponding FIRRTL definitions at the appropriate point in module construction.
+ // For the moment, we don't handle $readmemh or $readmemb.
+ // These will be part of a subsequent PR.
+ struct read_port {
+ string name;
+ bool clk_enable;
+ bool clk_parity;
+ bool transparent;
+ RTLIL::SigSpec clk;
+ RTLIL::SigSpec ena;
+ RTLIL::SigSpec addr;
+ read_port(string name, bool clk_enable, bool clk_parity, bool transparent, RTLIL::SigSpec clk, RTLIL::SigSpec ena, RTLIL::SigSpec addr) : name(name), clk_enable(clk_enable), clk_parity(clk_parity), transparent(transparent), clk(clk), ena(ena), addr(addr) {
+ // Current (3/13/2019) conventions:
+ // generate a constant 0 for clock and a constant 1 for enable if they are undefined.
+ if (!clk.is_fully_def())
+ this->clk = SigSpec(RTLIL::Const(0, 1));
+ if (!ena.is_fully_def())
+ this->ena = SigSpec(RTLIL::Const(1, 1));
+ }
+ string gen_read(const char * indent) {
+ string addr_expr = make_expr(addr);
+ string ena_expr = make_expr(ena);
+ string clk_expr = make_expr(clk);
+ string addr_str = stringf("%s%s.addr <= %s\n", indent, name.c_str(), addr_expr.c_str());
+ string ena_str = stringf("%s%s.en <= %s\n", indent, name.c_str(), ena_expr.c_str());
+ string clk_str = stringf("%s%s.clk <= asClock(%s)\n", indent, name.c_str(), clk_expr.c_str());
+ return addr_str + ena_str + clk_str;
+ }
+ };
+ struct write_port : read_port {
+ RTLIL::SigSpec mask;
+ write_port(string name, bool clk_enable, bool clk_parity, bool transparent, RTLIL::SigSpec clk, RTLIL::SigSpec ena, RTLIL::SigSpec addr, RTLIL::SigSpec mask) : read_port(name, clk_enable, clk_parity, transparent, clk, ena, addr), mask(mask) {
+ if (!clk.is_fully_def())
+ this->clk = SigSpec(RTLIL::Const(0));
+ if (!ena.is_fully_def())
+ this->ena = SigSpec(RTLIL::Const(0));
+ if (!mask.is_fully_def())
+ this->ena = SigSpec(RTLIL::Const(1));
+ }
+ string gen_read(const char * /* indent */) {
+ log_error("gen_read called on write_port: %s\n", name.c_str());
+ return stringf("gen_read called on write_port: %s\n", name.c_str());
+ }
+ string gen_write(const char * indent) {
+ string addr_expr = make_expr(addr);
+ string ena_expr = make_expr(ena);
+ string clk_expr = make_expr(clk);
+ string mask_expr = make_expr(mask);
+ string mask_str = stringf("%s%s.mask <= %s\n", indent, name.c_str(), mask_expr.c_str());
+ string addr_str = stringf("%s%s.addr <= %s\n", indent, name.c_str(), addr_expr.c_str());
+ string ena_str = stringf("%s%s.en <= %s\n", indent, name.c_str(), ena_expr.c_str());
+ string clk_str = stringf("%s%s.clk <= asClock(%s)\n", indent, name.c_str(), clk_expr.c_str());
+ return addr_str + ena_str + clk_str + mask_str;
+ }
+ };
+ /* Memories defined within this module. */
+ struct memory {
+ Cell *pCell; // for error reporting
+ string name; // memory name
+ int abits; // number of address bits
+ int size; // size (in units) of the memory
+ int width; // size (in bits) of each element
+ int read_latency;
+ int write_latency;
+ vector<read_port> read_ports;
+ vector<write_port> write_ports;
+ std::string init_file;
+ std::string init_file_srcFileSpec;
+ string srcLine;
+ memory(Cell *pCell, string name, int abits, int size, int width) : pCell(pCell), name(name), abits(abits), size(size), width(width), read_latency(0), write_latency(1), init_file(""), init_file_srcFileSpec("") {
+ // Provide defaults for abits or size if one (but not the other) is specified.
+ if (this->abits == 0 && this->size != 0) {
+ this->abits = ceil_log2(this->size);
+ } else if (this->abits != 0 && this->size == 0) {
+ this->size = 1 << this->abits;
+ }
+ // Sanity-check this construction.
+ if (this->name == "") {
+ log_error("Nameless memory%s\n", this->atLine());
+ }
+ if (this->abits == 0 && this->size == 0) {
+ log_error("Memory %s has zero address bits and size%s\n", this->name.c_str(), this->atLine());
+ }
+ if (this->width == 0) {
+ log_error("Memory %s has zero width%s\n", this->name.c_str(), this->atLine());
+ }
+ }
+ // We need a default constructor for the dict insert.
+ memory() : pCell(0), read_latency(0), write_latency(1), init_file(""), init_file_srcFileSpec(""){}
+
+ const char *atLine() {
+ if (srcLine == "") {
+ if (pCell) {
+ auto p = pCell->attributes.find("\\src");
+ srcLine = " at " + p->second.decode_string();
+ }
+ }
+ return srcLine.c_str();
+ }
+ void add_memory_read_port(read_port &rp) {
+ read_ports.push_back(rp);
+ }
+ void add_memory_write_port(write_port &wp) {
+ write_ports.push_back(wp);
+ }
+ void add_memory_file(std::string init_file, std::string init_file_srcFileSpec) {
+ this->init_file = init_file;
+ this->init_file_srcFileSpec = init_file_srcFileSpec;
+ }
+
+ };
+ dict<string, memory> memories;
+
+ void register_memory(memory &m)
+ {
+ memories[m.name] = m;
+ }
+
void register_reverse_wire_map(string id, SigSpec sig)
{
for (int i = 0; i < GetSize(sig); i++)
@@ -116,7 +235,7 @@ struct FirrtlWorker
{
}
- string make_expr(const SigSpec &sig)
+ static string make_expr(const SigSpec &sig)
{
string expr;
@@ -165,11 +284,9 @@ struct FirrtlWorker
std::string fid(RTLIL::IdString internal_id)
{
- const char *str = internal_id.c_str();
- return *str == '\\' ? str + 1 : str;
+ return make_id(internal_id);
}
-
std::string cellname(RTLIL::Cell *cell)
{
return fid(cell->name).c_str();
@@ -219,29 +336,43 @@ 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));
+ /* FALLTHRU */
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 */
+ /* FALLTHRU */
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"));
@@ -318,8 +449,10 @@ struct FirrtlWorker
string primop;
bool always_uint = false;
if (cell->type == "$not") primop = "not";
- else if (cell->type == "$neg") primop = "neg";
- else if (cell->type == "$logic_not") {
+ else if (cell->type == "$neg") {
+ primop = "neg";
+ is_signed = true; // Result of "neg" is signed (an SInt).
+ } else if (cell->type == "$logic_not") {
primop = "eq";
a_expr = stringf("%s, UInt(0)", a_expr.c_str());
}
@@ -431,6 +564,7 @@ struct FirrtlWorker
auto b_sig = cell->getPort("\\B");
if (b_sig.is_fully_const()) {
primop = "shl";
+ b_expr = std::to_string(b_sig.as_int());
} else {
primop = "dshl";
// Convert from FIRRTL left shift semantics.
@@ -444,6 +578,7 @@ struct FirrtlWorker
auto b_sig = cell->getPort("\\B");
if (b_sig.is_fully_const()) {
primop = "shr";
+ b_expr = std::to_string(b_sig.as_int());
} else {
primop = "dshr";
}
@@ -504,6 +639,7 @@ struct FirrtlWorker
int abits = cell->parameters.at("\\ABITS").as_int();
int width = cell->parameters.at("\\WIDTH").as_int();
int size = cell->parameters.at("\\SIZE").as_int();
+ memory m(cell, mem_id, abits, size, width);
int rd_ports = cell->parameters.at("\\RD_PORTS").as_int();
int wr_ports = cell->parameters.at("\\WR_PORTS").as_int();
@@ -520,33 +656,24 @@ struct FirrtlWorker
if (offset != 0)
log_error("Memory with nonzero offset: %s.%s\n", log_id(module), log_id(cell));
- cell_exprs.push_back(stringf(" mem %s:\n", mem_id.c_str()));
- cell_exprs.push_back(stringf(" data-type => UInt<%d>\n", width));
- cell_exprs.push_back(stringf(" depth => %d\n", size));
-
- for (int i = 0; i < rd_ports; i++)
- cell_exprs.push_back(stringf(" reader => r%d\n", i));
-
- for (int i = 0; i < wr_ports; i++)
- cell_exprs.push_back(stringf(" writer => w%d\n", i));
-
- cell_exprs.push_back(stringf(" read-latency => 0\n"));
- cell_exprs.push_back(stringf(" write-latency => 1\n"));
- cell_exprs.push_back(stringf(" read-under-write => undefined\n"));
-
for (int i = 0; i < rd_ports; i++)
{
if (rd_clk_enable[i] != State::S0)
log_error("Clocked read port %d on memory %s.%s.\n", i, log_id(module), log_id(cell));
+ SigSpec addr_sig = cell->getPort("\\RD_ADDR").extract(i*abits, abits);
SigSpec data_sig = cell->getPort("\\RD_DATA").extract(i*width, width);
- string addr_expr = make_expr(cell->getPort("\\RD_ADDR").extract(i*abits, abits));
-
- cell_exprs.push_back(stringf(" %s.r%d.addr <= %s\n", mem_id.c_str(), i, addr_expr.c_str()));
- cell_exprs.push_back(stringf(" %s.r%d.en <= UInt<1>(1)\n", mem_id.c_str(), i));
- cell_exprs.push_back(stringf(" %s.r%d.clk <= asClock(UInt<1>(0))\n", mem_id.c_str(), i));
-
- register_reverse_wire_map(stringf("%s.r%d.data", mem_id.c_str(), i), data_sig);
+ string addr_expr = make_expr(addr_sig);
+ string name(stringf("%s.r%d", m.name.c_str(), i));
+ bool clk_enable = false;
+ bool clk_parity = true;
+ bool transparency = false;
+ SigSpec ena_sig = RTLIL::SigSpec(RTLIL::State::S1, 1);
+ SigSpec clk_sig = RTLIL::SigSpec(RTLIL::State::S0, 1);
+ read_port rp(name, clk_enable, clk_parity, transparency, clk_sig, ena_sig, addr_sig);
+ m.add_memory_read_port(rp);
+ cell_exprs.push_back(rp.gen_read(indent.c_str()));
+ register_reverse_wire_map(stringf("%s.data", name.c_str()), data_sig);
}
for (int i = 0; i < wr_ports; i++)
@@ -557,9 +684,16 @@ struct FirrtlWorker
if (wr_clk_polarity[i] != State::S1)
log_error("Negedge write port %d on memory %s.%s.\n", i, log_id(module), log_id(cell));
- string addr_expr = make_expr(cell->getPort("\\WR_ADDR").extract(i*abits, abits));
- string data_expr = make_expr(cell->getPort("\\WR_DATA").extract(i*width, width));
- string clk_expr = make_expr(cell->getPort("\\WR_CLK").extract(i));
+ string name(stringf("%s.w%d", m.name.c_str(), i));
+ bool clk_enable = true;
+ bool clk_parity = true;
+ bool transparency = false;
+ SigSpec addr_sig =cell->getPort("\\WR_ADDR").extract(i*abits, abits);
+ string addr_expr = make_expr(addr_sig);
+ SigSpec data_sig =cell->getPort("\\WR_DATA").extract(i*width, width);
+ string data_expr = make_expr(data_sig);
+ SigSpec clk_sig = cell->getPort("\\WR_CLK").extract(i);
+ string clk_expr = make_expr(clk_sig);
SigSpec wen_sig = cell->getPort("\\WR_EN").extract(i*width, width);
string wen_expr = make_expr(wen_sig[0]);
@@ -568,13 +702,57 @@ struct FirrtlWorker
if (wen_sig[0] != wen_sig[i])
log_error("Complex write enable on port %d on memory %s.%s.\n", i, log_id(module), log_id(cell));
- cell_exprs.push_back(stringf(" %s.w%d.addr <= %s\n", mem_id.c_str(), i, addr_expr.c_str()));
- cell_exprs.push_back(stringf(" %s.w%d.data <= %s\n", mem_id.c_str(), i, data_expr.c_str()));
- cell_exprs.push_back(stringf(" %s.w%d.en <= %s\n", mem_id.c_str(), i, wen_expr.c_str()));
- cell_exprs.push_back(stringf(" %s.w%d.mask <= UInt<1>(1)\n", mem_id.c_str(), i));
- cell_exprs.push_back(stringf(" %s.w%d.clk <= asClock(%s)\n", mem_id.c_str(), i, clk_expr.c_str()));
+ SigSpec mask_sig = RTLIL::SigSpec(RTLIL::State::S1, 1);
+ write_port wp(name, clk_enable, clk_parity, transparency, clk_sig, wen_sig[0], addr_sig, mask_sig);
+ m.add_memory_write_port(wp);
+ cell_exprs.push_back(stringf("%s%s.data <= %s\n", indent.c_str(), name.c_str(), data_expr.c_str()));
+ cell_exprs.push_back(wp.gen_write(indent.c_str()));
}
+ register_memory(m);
+ continue;
+ }
+ if (cell->type.in("$memwr", "$memrd", "$meminit"))
+ {
+ std::string cell_type = fid(cell->type);
+ std::string mem_id = make_id(cell->parameters["\\MEMID"].decode_string());
+ int abits = cell->parameters.at("\\ABITS").as_int();
+ int width = cell->parameters.at("\\WIDTH").as_int();
+ memory *mp = nullptr;
+ if (cell->type == "$meminit" ) {
+ log_error("$meminit (%s.%s.%s) currently unsupported\n", log_id(module), log_id(cell), mem_id.c_str());
+ } else {
+ // It's a $memwr or $memrd. Remember the read/write port parameters for the eventual FIRRTL memory definition.
+ auto addrSig = cell->getPort("\\ADDR");
+ auto dataSig = cell->getPort("\\DATA");
+ auto enableSig = cell->getPort("\\EN");
+ auto clockSig = cell->getPort("\\CLK");
+ Const clk_enable = cell->parameters.at("\\CLK_ENABLE");
+ Const clk_polarity = cell->parameters.at("\\CLK_POLARITY");
+
+ // Do we already have an entry for this memory?
+ if (memories.count(mem_id) == 0) {
+ memory m(cell, mem_id, abits, 0, width);
+ register_memory(m);
+ }
+ mp = &memories.at(mem_id);
+ int portNum = 0;
+ bool transparency = false;
+ string data_expr = make_expr(dataSig);
+ if (cell->type.in("$memwr")) {
+ portNum = (int) mp->write_ports.size();
+ write_port wp(stringf("%s.w%d", mem_id.c_str(), portNum), clk_enable.as_bool(), clk_polarity.as_bool(), transparency, clockSig, enableSig, addrSig, dataSig);
+ mp->add_memory_write_port(wp);
+ cell_exprs.push_back(stringf("%s%s.data <= %s\n", indent.c_str(), wp.name.c_str(), data_expr.c_str()));
+ cell_exprs.push_back(wp.gen_write(indent.c_str()));
+ } else if (cell->type.in("$memrd")) {
+ portNum = (int) mp->read_ports.size();
+ read_port rp(stringf("%s.r%d", mem_id.c_str(), portNum), clk_enable.as_bool(), clk_polarity.as_bool(), transparency, clockSig, enableSig, addrSig);
+ mp->add_memory_read_port(rp);
+ cell_exprs.push_back(rp.gen_read(indent.c_str()));
+ register_reverse_wire_map(stringf("%s.data", rp.name.c_str()), dataSig);
+ }
+ }
continue;
}
@@ -752,6 +930,24 @@ struct FirrtlWorker
f << stringf("\n");
+ // If we have any memory definitions, output them.
+ for (auto kv : memories) {
+ memory &m = kv.second;
+ f << stringf(" mem %s:\n", m.name.c_str());
+ f << stringf(" data-type => UInt<%d>\n", m.width);
+ f << stringf(" depth => %d\n", m.size);
+ for (int i = 0; i < (int) m.read_ports.size(); i += 1) {
+ f << stringf(" reader => r%d\n", i);
+ }
+ for (int i = 0; i < (int) m.write_ports.size(); i += 1) {
+ f << stringf(" writer => w%d\n", i);
+ }
+ f << stringf(" read-latency => %d\n", m.read_latency);
+ f << stringf(" write-latency => %d\n", m.write_latency);
+ f << stringf(" read-under-write => undefined\n");
+ }
+ f << stringf("\n");
+
for (auto str : cell_exprs)
f << str;
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-08 14:58:26 +0000