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Added "opt_rmdff -keepdc"

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This commit is contained in:
Clifford Wolf 2016-09-30 17:02:38 +02:00
parent ca5462523e
commit ed519f578e
2 changed files with 20 additions and 7 deletions
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17
passes/opt/opt_rmdff.cc
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@ -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)
{
@ -115,7 +116,7 @@ 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);
}
@ -182,7 +183,7 @@ 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 +194,17 @@ 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())
{