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Improvements in greenpak4 shreg mapping

This commit is contained in:
Clifford Wolf 2016-04-23 23:10:13 +02:00
parent c9c5192cd6
commit 096c25d29d
1 changed files with 35 additions and 16 deletions
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51
passes/techmap/shregmap.cc
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@ -26,8 +26,8 @@ PRIVATE_NAMESPACE_BEGIN
struct ShregmapTech
{
virtual ~ShregmapTech() { }
virtual bool check_taps(const dict<int, SigBit> &taps) = 0;
virtual bool fixup_shreg(Cell *cell, dict<int, SigBit> &taps) = 0;
virtual bool analyze(vector<int> &taps) = 0;
virtual bool fixup(Cell *cell, dict<int, SigBit> &taps) = 0;
};
struct ShregmapOptions
@ -54,18 +54,22 @@ struct ShregmapOptions
struct ShregmapTechGreenpak4 : ShregmapTech
{
bool check_taps(const dict<int, SigBit> &taps)
bool analyze(vector<int> &taps)
{
if (GetSize(taps) > 2 && taps[0] == 0 && taps[2] < 17) {
taps.clear();
return true;
}
if (GetSize(taps) > 2)
return false;
for (auto tap : taps)
if (tap.first > 16) return false;
if (taps.back() > 16) return false;
return true;
}
bool fixup_shreg(Cell *cell, dict<int, SigBit> &taps)
bool fixup(Cell *cell, dict<int, SigBit> &taps)
{
auto D = cell->getPort("\\D");
auto C = cell->getPort("\\C");
@ -232,31 +236,47 @@ struct ShregmapWorker
Cell *first_cell = chain[cursor];
IdString q_port = opts.ffcells.at(first_cell->type).second;
dict<int, SigBit> taps;
dict<int, SigBit> taps_dict;
if (opts.tech)
{
vector<SigBit> qbits;
vector<int> taps;
for (int i = 0; i < depth; i++)
{
Cell *cell = chain[cursor+i];
auto qbit = sigmap(cell->getPort(q_port));
qbits.push_back(qbit);
if (sigbit_with_non_chain_users.count(qbit))
taps[i] = qbit;
taps.push_back(i);
}
while (depth > 0)
{
Cell *last_cell = chain[cursor+depth-1];
taps[depth-1] = sigmap(last_cell->getPort(q_port));
if (opts.tech->check_taps(taps))
if (taps.empty() || taps.back() < depth-1)
taps.push_back(depth-1);
if (opts.tech->analyze(taps))
break;
taps.erase(--depth);
taps.pop_back();
depth--;
}
depth = 0;
for (auto tap : taps) {
taps_dict[tap] = qbits.at(tap);
log_assert(depth < tap+1);
depth = tap+1;
}
}
if (depth < 2)
return;
if (depth < 2) {
cursor++;
continue;
}
Cell *last_cell = chain[cursor+depth-1];
@ -318,7 +338,7 @@ struct ShregmapWorker
first_cell->setPort(q_port, last_cell->getPort(q_port));
first_cell->setParam("\\DEPTH", depth);
if (opts.tech != nullptr && !opts.tech->fixup_shreg(first_cell, taps))
if (opts.tech != nullptr && !opts.tech->fixup(first_cell, taps_dict))
remove_cells.insert(first_cell);
for (int i = 1; i < depth; i++)
@ -479,7 +499,6 @@ struct ShregmapPass : public Pass {
string tech = args[++argidx];
if (tech == "greenpak4") {
clkpol = "pos";
opts.maxlen = 16;
opts.zinit = true;
opts.tech = new ShregmapTechGreenpak4;
} else {