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memory_dff: Remove now-useless write port handling.

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This commit is contained in:
Marcelina Kościelnicka 2021-02-23 19:42:51 +01:00
parent 89c74ffd71
commit a3528649c8
6 changed files with 19 additions and 82 deletions
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5
passes/memory/memory.cc
View file

@ -36,7 +36,7 @@ struct MemoryPass : public Pass {
log("This pass calls all the other memory_* passes in a useful order:\n");
log("\n");
log(" opt_mem\n");
log(" memory_dff [-nordff] (-memx implies -nordff)\n");
log(" memory_dff (skipped if called with -nordff or -memx)\n");
log(" opt_clean\n");
log(" memory_share\n");
log(" opt_clean\n");
@ -83,7 +83,8 @@ struct MemoryPass : public Pass {
extra_args(args, argidx, design);
Pass::call(design, "opt_mem");
Pass::call(design, flag_nordff ? "memory_dff -nordff" : "memory_dff");
if (!flag_nordff)
Pass::call(design, "memory_dff");
Pass::call(design, "opt_clean");
Pass::call(design, "memory_share");
if (flag_memx)

78
passes/memory/memory_dff.cc
View file

@ -33,7 +33,6 @@ struct MemoryDffWorker
vector<Cell*> dff_cells;
dict<SigBit, SigBit> invbits;
dict<SigBit, int> sigbit_users_count;
pool<Cell*> forward_merged_dffs, candidate_dffs;
FfInitVals initvals;
MemoryDffWorker(Module *module) : module(module), sigmap(module)
@ -113,7 +112,6 @@ struct MemoryDffWorker
bit = d;
clk = this_clk;
clk_polarity = this_clk_polarity;
candidate_dffs.insert(cell);
goto replaced_this_bit;
}
@ -135,8 +133,6 @@ struct MemoryDffWorker
for (auto cell : dff_cells)
{
if (forward_merged_dffs.count(cell))
continue;
if (!cell->type.in(ID($dff), ID($dffe)))
continue;
@ -186,7 +182,6 @@ struct MemoryDffWorker
clk_polarity = this_clk_polarity;
en = this_en;
en_polarity = this_en_polarity;
candidate_dffs.insert(cell);
goto replaced_this_bit;
}
@ -197,51 +192,6 @@ struct MemoryDffWorker
return true;
}
void handle_wr_cell(RTLIL::Cell *cell)
{
log("Checking cell `%s' in module `%s': ", cell->name.c_str(), module->name.c_str());
RTLIL::SigSpec clk = RTLIL::SigSpec(RTLIL::State::Sx);
bool clk_polarity = 0;
candidate_dffs.clear();
RTLIL::SigSpec sig_addr = cell->getPort(ID::ADDR);
if (!find_sig_before_dff(sig_addr, clk, clk_polarity)) {
log("no (compatible) $dff for address input found.\n");
return;
}
RTLIL::SigSpec sig_data = cell->getPort(ID::DATA);
if (!find_sig_before_dff(sig_data, clk, clk_polarity)) {
log("no (compatible) $dff for data input found.\n");
return;
}
RTLIL::SigSpec sig_en = cell->getPort(ID::EN);
if (!find_sig_before_dff(sig_en, clk, clk_polarity)) {
log("no (compatible) $dff for enable input found.\n");
return;
}
if (clk != RTLIL::SigSpec(RTLIL::State::Sx))
{
for (auto cell : candidate_dffs)
forward_merged_dffs.insert(cell);
cell->setPort(ID::CLK, clk);
cell->setPort(ID::ADDR, sig_addr);
cell->setPort(ID::DATA, sig_data);
cell->setPort(ID::EN, sig_en);
cell->parameters[ID::CLK_ENABLE] = RTLIL::Const(1);
cell->parameters[ID::CLK_POLARITY] = RTLIL::Const(clk_polarity);
log("merged $dff to cell.\n");
return;
}
log("no (compatible) $dff found.\n");
}
void disconnect_dff(RTLIL::SigSpec sig)
{
sigmap.apply(sig);
@ -309,7 +259,7 @@ struct MemoryDffWorker
log("no (compatible) $dff found.\n");
}
void run(bool flag_wr_only)
void run()
{
for (auto wire : module->wires()) {
if (wire->port_output)
@ -337,51 +287,37 @@ struct MemoryDffWorker
}
for (auto cell : module->selected_cells())
if (cell->type == ID($memwr) && !cell->parameters[ID::CLK_ENABLE].as_bool())
handle_wr_cell(cell);
if (!flag_wr_only)
for (auto cell : module->selected_cells())
if (cell->type == ID($memrd) && !cell->parameters[ID::CLK_ENABLE].as_bool())
handle_rd_cell(cell);
if (cell->type == ID($memrd) && !cell->parameters[ID::CLK_ENABLE].as_bool())
handle_rd_cell(cell);
}
};
struct MemoryDffPass : public Pass {
MemoryDffPass() : Pass("memory_dff", "merge input/output DFFs into memories") { }
MemoryDffPass() : Pass("memory_dff", "merge input/output DFFs into memory read ports") { }
void help() override
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
log(" memory_dff [options] [selection]\n");
log("\n");
log("This pass detects DFFs at memory ports and merges them into the memory port.\n");
log("This pass detects DFFs at memory read ports and merges them into the memory port.\n");
log("I.e. it consumes an asynchronous memory port and the flip-flops at its\n");
log("interface and yields a synchronous memory port.\n");
log("\n");
log(" -nordfff\n");
log(" do not merge registers on read ports\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override
{
bool flag_wr_only = false;
log_header(design, "Executing MEMORY_DFF pass (merging $dff cells to $memrd and $memwr).\n");
log_header(design, "Executing MEMORY_DFF pass (merging $dff cells to $memrd).\n");
size_t argidx;
for (argidx = 1; argidx < args.size(); argidx++) {
if (args[argidx] == "-nordff" || args[argidx] == "-wr_only") {
flag_wr_only = true;
continue;
}
break;
}
extra_args(args, argidx, design);
for (auto mod : design->selected_modules()) {
MemoryDffWorker worker(mod);
worker.run(flag_wr_only);
worker.run();
}
}
} MemoryDffPass;

2
passes/memory/memory_nordff.cc
View file

@ -33,7 +33,7 @@ struct MemoryNordffPass : public Pass {
log(" memory_nordff [options] [selection]\n");
log("\n");
log("This pass extracts FFs from memory read ports. This results in a netlist\n");
log("similar to what one would get from calling memory_dff with -nordff.\n");
log("similar to what one would get from not calling memory_dff.\n");
log("\n");
}
void execute(std::vector<std::string> args, RTLIL::Design *design) override