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Diffstat (limited to 'passes/opt')
-rw-r--r--passes/opt/opt.cc10
-rw-r--r--passes/opt/opt_rmdff.cc35
2 files changed, 33 insertions, 12 deletions
diff --git a/passes/opt/opt.cc b/passes/opt/opt.cc
index 13ea5469..021c1a03 100644
--- a/passes/opt/opt.cc
+++ b/passes/opt/opt.cc
@@ -44,7 +44,7 @@ struct OptPass : public Pass {
log(" opt_muxtree\n");
log(" opt_reduce [-fine] [-full]\n");
log(" opt_merge [-share_all]\n");
- log(" opt_rmdff\n");
+ log(" opt_rmdff [-keepdc]\n");
log(" opt_clean [-purge]\n");
log(" opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc]\n");
log(" while <changed design>\n");
@@ -54,7 +54,7 @@ struct OptPass : public Pass {
log(" do\n");
log(" opt_expr [-mux_undef] [-mux_bool] [-undriven] [-clkinv] [-fine] [-full] [-keepdc]\n");
log(" opt_merge [-share_all]\n");
- log(" opt_rmdff\n");
+ log(" opt_rmdff [-keepdc]\n");
log(" opt_clean [-purge]\n");
log(" while <changed design in opt_rmdff>\n");
log("\n");
@@ -69,6 +69,7 @@ struct OptPass : public Pass {
std::string opt_expr_args;
std::string opt_reduce_args;
std::string opt_merge_args;
+ std::string opt_rmdff_args;
bool fast_mode = false;
log_header(design, "Executing OPT pass (performing simple optimizations).\n");
@@ -108,6 +109,7 @@ struct OptPass : public Pass {
}
if (args[argidx] == "-keepdc") {
opt_expr_args += " -keepdc";
+ opt_rmdff_args += " -keepdc";
continue;
}
if (args[argidx] == "-share_all") {
@@ -128,7 +130,7 @@ struct OptPass : public Pass {
Pass::call(design, "opt_expr" + opt_expr_args);
Pass::call(design, "opt_merge" + opt_merge_args);
design->scratchpad_unset("opt.did_something");
- Pass::call(design, "opt_rmdff");
+ Pass::call(design, "opt_rmdff" + opt_rmdff_args);
if (design->scratchpad_get_bool("opt.did_something") == false)
break;
Pass::call(design, "opt_clean" + opt_clean_args);
@@ -145,7 +147,7 @@ struct OptPass : public Pass {
Pass::call(design, "opt_muxtree");
Pass::call(design, "opt_reduce" + opt_reduce_args);
Pass::call(design, "opt_merge" + opt_merge_args);
- Pass::call(design, "opt_rmdff");
+ Pass::call(design, "opt_rmdff" + opt_rmdff_args);
Pass::call(design, "opt_clean" + opt_clean_args);
Pass::call(design, "opt_expr" + opt_expr_args);
if (design->scratchpad_get_bool("opt.did_something") == false)
diff --git a/passes/opt/opt_rmdff.cc b/passes/opt/opt_rmdff.cc
index fa954afa..922f086f 100644
--- a/passes/opt/opt_rmdff.cc
+++ b/passes/opt/opt_rmdff.cc
@@ -29,6 +29,7 @@ PRIVATE_NAMESPACE_BEGIN
SigMap assign_map, dff_init_map;
SigSet<RTLIL::Cell*> mux_drivers;
dict<SigBit, pool<SigBit>> init_attributes;
+bool keepdc;
void remove_init_attr(SigSpec sig)
{
@@ -71,7 +72,11 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
RTLIL::SigSpec sig_d, sig_q, sig_c, sig_r;
RTLIL::Const val_cp, val_rp, val_rv;
- if (dff->type == "$_DFF_N_" || dff->type == "$_DFF_P_") {
+ if (dff->type == "$_FF_") {
+ sig_d = dff->getPort("\\D");
+ sig_q = dff->getPort("\\Q");
+ }
+ else if (dff->type == "$_DFF_N_" || dff->type == "$_DFF_P_") {
sig_d = dff->getPort("\\D");
sig_q = dff->getPort("\\Q");
sig_c = dff->getPort("\\C");
@@ -89,6 +94,10 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
val_rp = RTLIL::Const(dff->type[7] == 'P', 1);
val_rv = RTLIL::Const(dff->type[8] == '1', 1);
}
+ else if (dff->type == "$ff") {
+ sig_d = dff->getPort("\\D");
+ sig_q = dff->getPort("\\Q");
+ }
else if (dff->type == "$dff") {
sig_d = dff->getPort("\\D");
sig_q = dff->getPort("\\Q");
@@ -115,12 +124,12 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
bool has_init = false;
RTLIL::Const val_init;
for (auto bit : dff_init_map(sig_q).to_sigbit_vector()) {
- if (bit.wire == NULL)
+ if (bit.wire == NULL || keepdc)
has_init = true;
val_init.bits.push_back(bit.wire == NULL ? bit.data : RTLIL::State::Sx);
}
- if (dff->type == "$dff" && mux_drivers.has(sig_d)) {
+ if (dff->type.in("$ff", "$dff") && mux_drivers.has(sig_d)) {
std::set<RTLIL::Cell*> muxes;
mux_drivers.find(sig_d, muxes);
for (auto mux : muxes) {
@@ -137,7 +146,7 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
}
}
- if (sig_c.is_fully_const() && (!sig_r.size() || !has_init || val_init == val_rv)) {
+ if (!sig_c.empty() && sig_c.is_fully_const() && (!sig_r.size() || !has_init || val_init == val_rv)) {
if (val_rv.bits.size() == 0)
val_rv = val_init;
mod->connect(sig_q, val_rv);
@@ -182,7 +191,7 @@ struct OptRmdffPass : public Pass {
{
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n");
- log(" opt_rmdff [selection]\n");
+ log(" opt_rmdff [-keepdc] [selection]\n");
log("\n");
log("This pass identifies flip-flops with constant inputs and replaces them with\n");
log("a constant driver.\n");
@@ -193,7 +202,17 @@ struct OptRmdffPass : public Pass {
int total_count = 0, total_initdrv = 0;
log_header(design, "Executing OPT_RMDFF pass (remove dff with constant values).\n");
- extra_args(args, 1, design);
+ keepdc = false;
+
+ size_t argidx;
+ for (argidx = 1; argidx < args.size(); argidx++) {
+ if (args[argidx] == "-keepdc") {
+ keepdc = true;
+ continue;
+ }
+ break;
+ }
+ extra_args(args, argidx, design);
for (auto module : design->selected_modules())
{
@@ -243,10 +262,10 @@ struct OptRmdffPass : public Pass {
if (!design->selected(module, cell))
continue;
- if (cell->type.in("$_DFF_N_", "$_DFF_P_",
+ if (cell->type.in("$_FF_", "$_DFF_N_", "$_DFF_P_",
"$_DFF_NN0_", "$_DFF_NN1_", "$_DFF_NP0_", "$_DFF_NP1_",
"$_DFF_PN0_", "$_DFF_PN1_", "$_DFF_PP0_", "$_DFF_PP1_",
- "$dff", "$adff"))
+ "$ff", "$dff", "$adff"))
dff_list.push_back(cell->name);
if (cell->type == "$dlatch")
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 22:42:49 +0000