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Diffstat (limited to 'techlibs/ice40/ice40_opt.cc')
-rw-r--r--techlibs/ice40/ice40_opt.cc123
1 files changed, 99 insertions, 24 deletions
diff --git a/techlibs/ice40/ice40_opt.cc b/techlibs/ice40/ice40_opt.cc
index ae72f5d64..925ab31bb 100644
--- a/techlibs/ice40/ice40_opt.cc
+++ b/techlibs/ice40/ice40_opt.cc
@@ -26,7 +26,14 @@
USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
-static void run_ice40_opts(Module *module, bool unlut_mode)
+static SigBit get_bit_or_zero(const SigSpec &sig)
+{
+ if (GetSize(sig) == 0)
+ return State::S0;
+ return sig[0];
+}
+
+static void run_ice40_opts(Module *module)
{
pool<SigBit> optimized_co;
vector<Cell*> sb_lut_cells;
@@ -34,6 +41,11 @@ static void run_ice40_opts(Module *module, bool unlut_mode)
for (auto cell : module->selected_cells())
{
+ if (!cell->type.in("\\SB_LUT4", "\\SB_CARRY", "$__ICE40_CARRY_WRAPPER"))
+ continue;
+ if (cell->has_keep_attr())
+ continue;
+
if (cell->type == "\\SB_LUT4")
{
sb_lut_cells.push_back(cell);
@@ -45,7 +57,11 @@ static void run_ice40_opts(Module *module, bool unlut_mode)
SigSpec non_const_inputs, replacement_output;
int count_zeros = 0, count_ones = 0;
- SigBit inbit[3] = {cell->getPort("\\I0"), cell->getPort("\\I1"), cell->getPort("\\CI")};
+ SigBit inbit[3] = {
+ get_bit_or_zero(cell->getPort("\\I0")),
+ get_bit_or_zero(cell->getPort("\\I1")),
+ get_bit_or_zero(cell->getPort("\\CI"))
+ };
for (int i = 0; i < 3; i++)
if (inbit[i].wire == nullptr) {
if (inbit[i] == State::S1)
@@ -63,8 +79,8 @@ static void run_ice40_opts(Module *module, bool unlut_mode)
replacement_output = non_const_inputs;
if (GetSize(replacement_output)) {
- optimized_co.insert(sigmap(cell->getPort("\\CO")));
- module->connect(cell->getPort("\\CO"), replacement_output);
+ optimized_co.insert(sigmap(cell->getPort("\\CO")[0]));
+ module->connect(cell->getPort("\\CO")[0], replacement_output);
module->design->scratchpad_set_bool("opt.did_something", true);
log("Optimized away SB_CARRY cell %s.%s: CO=%s\n",
log_id(module), log_id(cell), log_signal(replacement_output));
@@ -72,21 +88,83 @@ static void run_ice40_opts(Module *module, bool unlut_mode)
}
continue;
}
+
+ if (cell->type == "$__ICE40_CARRY_WRAPPER")
+ {
+ SigSpec non_const_inputs, replacement_output;
+ int count_zeros = 0, count_ones = 0;
+
+ SigBit inbit[3] = {
+ cell->getPort("\\A"),
+ cell->getPort("\\B"),
+ cell->getPort("\\CI")
+ };
+ for (int i = 0; i < 3; i++)
+ if (inbit[i].wire == nullptr) {
+ if (inbit[i] == State::S1)
+ count_ones++;
+ else
+ count_zeros++;
+ } else
+ non_const_inputs.append(inbit[i]);
+
+ if (count_zeros >= 2)
+ replacement_output = State::S0;
+ else if (count_ones >= 2)
+ replacement_output = State::S1;
+ else if (GetSize(non_const_inputs) == 1)
+ replacement_output = non_const_inputs;
+
+ if (GetSize(replacement_output)) {
+ optimized_co.insert(sigmap(cell->getPort("\\CO")[0]));
+ auto it = cell->attributes.find(ID(SB_LUT4.name));
+ if (it != cell->attributes.end()) {
+ module->rename(cell, it->second.decode_string());
+ decltype(Cell::attributes) new_attr;
+ for (const auto &a : cell->attributes)
+ if (a.first.begins_with("\\SB_LUT4.\\"))
+ new_attr[a.first.c_str() + strlen("\\SB_LUT4.")] = a.second;
+ else if (a.first == ID(src))
+ new_attr.insert(std::make_pair(a.first, a.second));
+ else if (a.first.in(ID(SB_LUT4.name), ID::keep, ID(module_not_derived)))
+ continue;
+ else if (a.first.begins_with("\\SB_CARRY.\\"))
+ continue;
+ else
+ log_abort();
+ cell->attributes = std::move(new_attr);
+ }
+ module->connect(cell->getPort("\\CO")[0], replacement_output);
+ module->design->scratchpad_set_bool("opt.did_something", true);
+ log("Optimized $__ICE40_CARRY_WRAPPER cell back to logic (without SB_CARRY) %s.%s: CO=%s\n",
+ log_id(module), log_id(cell), log_signal(replacement_output));
+ cell->type = "$lut";
+ auto I3 = get_bit_or_zero(cell->getPort(cell->getParam(ID(I3_IS_CI)).as_bool() ? ID(CI) : ID(I3)));
+ cell->setPort("\\A", { I3, inbit[1], inbit[0], get_bit_or_zero(cell->getPort("\\I0")) });
+ cell->setPort("\\Y", cell->getPort("\\O"));
+ cell->unsetPort("\\B");
+ cell->unsetPort("\\CI");
+ cell->unsetPort("\\I0");
+ cell->unsetPort("\\I3");
+ cell->unsetPort("\\CO");
+ cell->unsetPort("\\O");
+ cell->setParam("\\WIDTH", 4);
+ cell->unsetParam("\\I3_IS_CI");
+ }
+ continue;
+ }
}
for (auto cell : sb_lut_cells)
{
SigSpec inbits;
- inbits.append(cell->getPort("\\I0"));
- inbits.append(cell->getPort("\\I1"));
- inbits.append(cell->getPort("\\I2"));
- inbits.append(cell->getPort("\\I3"));
+ inbits.append(get_bit_or_zero(cell->getPort("\\I0")));
+ inbits.append(get_bit_or_zero(cell->getPort("\\I1")));
+ inbits.append(get_bit_or_zero(cell->getPort("\\I2")));
+ inbits.append(get_bit_or_zero(cell->getPort("\\I3")));
sigmap.apply(inbits);
- if (unlut_mode)
- goto remap_lut;
-
if (optimized_co.count(inbits[0])) goto remap_lut;
if (optimized_co.count(inbits[1])) goto remap_lut;
if (optimized_co.count(inbits[2])) goto remap_lut;
@@ -104,8 +182,13 @@ static void run_ice40_opts(Module *module, bool unlut_mode)
cell->setParam("\\LUT", cell->getParam("\\LUT_INIT"));
cell->unsetParam("\\LUT_INIT");
- cell->setPort("\\A", SigSpec({cell->getPort("\\I3"), cell->getPort("\\I2"), cell->getPort("\\I1"), cell->getPort("\\I0")}));
- cell->setPort("\\Y", cell->getPort("\\O"));
+ cell->setPort("\\A", SigSpec({
+ get_bit_or_zero(cell->getPort("\\I3")),
+ get_bit_or_zero(cell->getPort("\\I2")),
+ get_bit_or_zero(cell->getPort("\\I1")),
+ get_bit_or_zero(cell->getPort("\\I0"))
+ }));
+ cell->setPort("\\Y", cell->getPort("\\O")[0]);
cell->unsetPort("\\I0");
cell->unsetPort("\\I1");
cell->unsetPort("\\I2");
@@ -120,7 +203,7 @@ static void run_ice40_opts(Module *module, bool unlut_mode)
struct Ice40OptPass : public Pass {
Ice40OptPass() : Pass("ice40_opt", "iCE40: perform simple optimizations") { }
- virtual void help()
+ void help() YS_OVERRIDE
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
@@ -136,14 +219,10 @@ struct Ice40OptPass : public Pass {
log(" opt_clean\n");
log(" while <changed design>\n");
log("\n");
- log("When called with the option -unlut, this command will transform all already\n");
- log("mapped SB_LUT4 cells back to logic.\n");
- log("\n");
}
- virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+ void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
{
string opt_expr_args = "-mux_undef -undriven";
- bool unlut_mode = false;
log_header(design, "Executing ICE40_OPT pass (performing simple optimizations).\n");
log_push();
@@ -154,10 +233,6 @@ struct Ice40OptPass : public Pass {
opt_expr_args += " -full";
continue;
}
- if (args[argidx] == "-unlut") {
- unlut_mode = true;
- continue;
- }
break;
}
extra_args(args, argidx, design);
@@ -168,7 +243,7 @@ struct Ice40OptPass : public Pass {
log_header(design, "Running ICE40 specific optimizations.\n");
for (auto module : design->selected_modules())
- run_ice40_opts(module, unlut_mode);
+ run_ice40_opts(module);
Pass::call(design, "opt_expr " + opt_expr_args);
Pass::call(design, "opt_merge");
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-15 17:01:03 +0000