kernel/mem: Add model for wide ports.

Such ports cannot actually be created or used yet, this just adds the
necessary plumbing in the helper.  Subsequent commits will gradually
add wide port support to various yosys passes.

2 files changed, 28 insertions, 6 deletions

diff --git a/kernel/mem.cc b/kernel/mem.cc
index 2a51ec5d9..2285cf74d 100644
--- a/kernel/mem.cc
+++ b/kernel/mem.cc
@@ -121,6 +121,8 @@ void Mem::emit() {
 			abits = std::max(abits, GetSize(port.addr));
 		cell->parameters[ID::ABITS] = Const(abits);
 		for (auto &port : rd_ports) {
+			// TODO: remove
+			log_assert(port.wide_log2 == 0);
 			if (port.cell) {
 				module->remove(port.cell);
 				port.cell = nullptr;
@@ -152,6 +154,8 @@ void Mem::emit() {
 		cell->setPort(ID::RD_ADDR, rd_addr);
 		cell->setPort(ID::RD_DATA, rd_data);
 		for (auto &port : wr_ports) {
+			// TODO: remove
+			log_assert(port.wide_log2 == 0);
 			if (port.cell) {
 				module->remove(port.cell);
 				port.cell = nullptr;
@@ -206,7 +210,7 @@ void Mem::emit() {
 				port.cell = module->addCell(NEW_ID, ID($memrd));
 			port.cell->parameters[ID::MEMID] = memid.str();
 			port.cell->parameters[ID::ABITS] = GetSize(port.addr);
-			port.cell->parameters[ID::WIDTH] = width;
+			port.cell->parameters[ID::WIDTH] = width << port.wide_log2;
 			port.cell->parameters[ID::CLK_ENABLE] = port.clk_enable;
 			port.cell->parameters[ID::CLK_POLARITY] = port.clk_polarity;
 			port.cell->parameters[ID::TRANSPARENT] = port.transparent;
@@ -221,7 +225,7 @@ void Mem::emit() {
 				port.cell = module->addCell(NEW_ID, ID($memwr));
 			port.cell->parameters[ID::MEMID] = memid.str();
 			port.cell->parameters[ID::ABITS] = GetSize(port.addr);
-			port.cell->parameters[ID::WIDTH] = width;
+			port.cell->parameters[ID::WIDTH] = width << port.wide_log2;
 			port.cell->parameters[ID::CLK_ENABLE] = port.clk_enable;
 			port.cell->parameters[ID::CLK_POLARITY] = port.clk_polarity;
 			port.cell->parameters[ID::PRIORITY] = idx++;
@@ -264,23 +268,32 @@ Const Mem::get_init_data() const {
 }
 
 void Mem::check() {
+	int max_wide_log2 = 0;
 	for (auto &port : rd_ports) {
 		if (port.removed)
 			continue;
 		log_assert(GetSize(port.clk) == 1);
 		log_assert(GetSize(port.en) == 1);
-		log_assert(GetSize(port.data) == width);
+		log_assert(GetSize(port.data) == (width << port.wide_log2));
 		if (!port.clk_enable) {
 			log_assert(!port.transparent);
 		}
+		for (int j = 0; j < port.wide_log2; j++) {
+			log_assert(port.addr[j] == State::S0);
+		}
+		max_wide_log2 = std::max(max_wide_log2, port.wide_log2);
 	}
 	for (int i = 0; i < GetSize(wr_ports); i++) {
 		auto &port = wr_ports[i];
 		if (port.removed)
 			continue;
 		log_assert(GetSize(port.clk) == 1);
-		log_assert(GetSize(port.en) == width);
-		log_assert(GetSize(port.data) == width);
+		log_assert(GetSize(port.en) == (width << port.wide_log2));
+		log_assert(GetSize(port.data) == (width << port.wide_log2));
+		for (int j = 0; j < port.wide_log2; j++) {
+			log_assert(port.addr[j] == State::S0);
+		}
+		max_wide_log2 = std::max(max_wide_log2, port.wide_log2);
 		log_assert(GetSize(port.priority_mask) == GetSize(wr_ports));
 		for (int j = 0; j < GetSize(wr_ports); j++) {
 			auto &wport = wr_ports[j];
@@ -294,6 +307,9 @@ void Mem::check() {
 			}
 		}
 	}
+	int mask = (1 << max_wide_log2) - 1;
+	log_assert(!(start_offset & mask));
+	log_assert(!(size & mask));
 }
 
 namespace {
@@ -331,6 +347,7 @@ namespace {
 				mrd.en = cell->getPort(ID::EN);
 				mrd.addr = cell->getPort(ID::ADDR);
 				mrd.data = cell->getPort(ID::DATA);
+				mrd.wide_log2 = ceil_log2(GetSize(mrd.data) / mem->width);
 				res.rd_ports.push_back(mrd);
 			}
 		}
@@ -346,6 +363,7 @@ namespace {
 				mwr.en = cell->getPort(ID::EN);
 				mwr.addr = cell->getPort(ID::ADDR);
 				mwr.data = cell->getPort(ID::DATA);
+				mwr.wide_log2 = ceil_log2(GetSize(mwr.data) / mem->width);
 				ports.push_back(std::make_pair(cell->parameters.at(ID::PRIORITY).as_int(), mwr));
 			}
 			std::sort(ports.begin(), ports.end(), [](const std::pair<int, MemWr> &a, const std::pair<int, MemWr> &b) { return a.first < b.first; });
@@ -424,6 +442,7 @@ namespace {
 		}
 		for (int i = 0; i < cell->parameters.at(ID::RD_PORTS).as_int(); i++) {
 			MemRd mrd;
+			mrd.wide_log2 = 0;
 			mrd.clk_enable = cell->parameters.at(ID::RD_CLK_ENABLE).extract(i, 1).as_bool();
 			mrd.clk_polarity = cell->parameters.at(ID::RD_CLK_POLARITY).extract(i, 1).as_bool();
 			mrd.transparent = cell->parameters.at(ID::RD_TRANSPARENT).extract(i, 1).as_bool();
@@ -435,6 +454,7 @@ namespace {
 		}
 		for (int i = 0; i < cell->parameters.at(ID::WR_PORTS).as_int(); i++) {
 			MemWr mwr;
+			mwr.wide_log2 = 0;
 			mwr.clk_enable = cell->parameters.at(ID::WR_CLK_ENABLE).extract(i, 1).as_bool();
 			mwr.clk_polarity = cell->parameters.at(ID::WR_CLK_POLARITY).extract(i, 1).as_bool();
 			mwr.clk = cell->getPort(ID::WR_CLK).extract(i, 1);
@@ -507,7 +527,7 @@ Cell *Mem::extract_rdff(int idx, FfInitVals *initvals) {
 	}
 	else
 	{
-		SigSpec sig_d = module->addWire(stringf("%s$rdreg[%d]$d", memid.c_str(), idx), width);
+		SigSpec sig_d = module->addWire(stringf("%s$rdreg[%d]$d", memid.c_str(), idx), GetSize(port.data));
 		SigSpec sig_q = port.data;
 		port.data = sig_d;
 		c = module->addDffe(stringf("%s$rdreg[%d]", memid.c_str(), idx), port.clk, port.en, sig_d, sig_q, port.clk_polarity, true);
diff --git a/kernel/mem.h b/kernel/mem.h
index af06e970a..e0d8c277f 100644
--- a/kernel/mem.h
+++ b/kernel/mem.h
@@ -29,6 +29,7 @@ struct MemRd {
 	bool removed;
 	dict<IdString, Const> attributes;
 	Cell *cell;
+	int wide_log2;
 	bool clk_enable, clk_polarity;
 	bool transparent;
 	SigSpec clk, en, addr, data;
@@ -39,6 +40,7 @@ struct MemWr {
 	bool removed;
 	dict<IdString, Const> attributes;
 	Cell *cell;
+	int wide_log2;
 	bool clk_enable, clk_polarity;
 	std::vector<bool> priority_mask;
 	SigSpec clk, en, addr, data;