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mistral: improve ALM packing in LABs #1170

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mistral: improve ALM packing in LABs #1170

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f47ec47
mistral: count number of LABs in use
Ravenslofty Jun 5, 2023
ff094be
mistral: improve ALM packing in LABs
Ravenslofty Jun 5, 2023
3e739fd
mistral: LD-aware TD checking
Ravenslofty Jun 8, 2023
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86 changes: 83 additions & 3 deletions mistral/lab.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -534,6 +534,15 @@ void Arch::update_alm_input_count(uint32_t lab, uint8_t alm)
alm_data.unique_input_count = total_inputs;
}

const std::array<int, 6> tdmux_set = {
0, // A
1, // B
0, // C
1, // D
2, // E
3, // F
};

bool Arch::check_lab_input_count(uint32_t lab) const
{
// There are only 46 TD signals available to route signals from general routing to the ALM input. Currently, we
Expand All @@ -544,10 +553,75 @@ bool Arch::check_lab_input_count(uint32_t lab) const
// currently perfunctory place and route algorithms to achieve satisfactory runtimes.
int count = 0;
auto &lab_data = labs.at(lab);
for (int i = 0; i < 10; i++) {
count += lab_data.alms.at(i).unique_input_count;
pool<std::pair<IdString, int>> unique_inputs;

for (int alm = 0; alm < 10; alm++) {
// TODO: duplication with above
auto &alm_data = labs.at(lab).alms.at(alm);
// Get cells into an array for fast access
std::array<const CellInfo *, 2> luts{getBoundBelCell(alm_data.lut_bels[0]), getBoundBelCell(alm_data.lut_bels[1])};
std::array<const CellInfo *, 4> ffs{getBoundBelCell(alm_data.ff_bels[0]), getBoundBelCell(alm_data.ff_bels[1]),
getBoundBelCell(alm_data.ff_bels[2]), getBoundBelCell(alm_data.ff_bels[3])};
for (int i = 0; i < 2; i++) {
if (!luts[i])
continue;

for (int j = 0; j < luts[i]->combInfo.lut_input_count; j++)
if (luts[i]->combInfo.lut_in[j]) {
// LD routing outputs

const pool<int> ld_set_c = {1, 2, 4, 7};

const pool<int> ld_inputs_a = {2, 3, 4, 5, 10, 13, 14};
const pool<int> ld_inputs_b = {0, 1, 7, 9, 12, 18};
const pool<int> ld_inputs_c = {6, 8, 11, 16, 17};
const pool<int> ld_inputs_d = {15, 19};

// could this be driven by LD?
if (luts[i]->combInfo.lut_in[j]->driver.cell->bel.pos == alm_data.lut_bels[i].pos) {
auto dst_lut = 2 * alm + i;
auto& data = bel_data(luts[i]->combInfo.lut_in[j]->driver.cell->bel);
auto& src_alm_data = labs.at(data.lab_data.lab).alms.at(data.lab_data.alm);
bool ok = false;
int src_lut = 2 * data.lab_data.alm;
if (data.type == id_MISTRAL_MCOMB || data.type == id_MISTRAL_COMB) {
src_lut += data.lab_data.idx;
ok = true;
}
if (data.type == id_MISTRAL_FF && data.lab_data.idx & 1 == 1) {
src_lut += (data.lab_data.idx - 1) / 2;
ok = true;
}
if (ok && dst_lut & 1 == 0 && ld_inputs_a.count(src_lut))
continue;
if (ok && dst_lut & 1 == 1 && ld_inputs_b.count(src_lut))
continue;
if (ok && ld_set_c.count(dst_lut) && ld_inputs_c.count(src_lut))
continue;
if (ok && !ld_set_c.count(dst_lut) && ld_inputs_d.count(src_lut))
continue;
}

unique_inputs.insert(std::make_pair(luts[i]->combInfo.lut_in[j]->name, tdmux_set.at(j)));
}
}
for (int i = 0; i < 4; i++) {
const CellInfo *ff = ffs[i];
if (!ff)
continue;
if (ff->ffInfo.sdata) {
unique_inputs.insert(std::make_pair(ff->ffInfo.sdata->name, tdmux_set.at(4)));
unique_inputs.insert(std::make_pair(ff->ffInfo.sdata->name, tdmux_set.at(5)));
}
// FF input doesn't consume routing resources if driven by associated LUT
if (ff->ffInfo.datain && (!luts[i / 2] || ff->ffInfo.datain != luts[i / 2]->combInfo.comb_out)) {
unique_inputs.insert(std::make_pair(ff->ffInfo.datain->name, tdmux_set.at(4)));
unique_inputs.insert(std::make_pair(ff->ffInfo.datain->name, tdmux_set.at(5)));
}
}
}
return (count <= 42);

return (unique_inputs.size() <= 42);
}

bool Arch::check_mlab_groups(uint32_t lab) const
Expand Down Expand Up @@ -690,12 +764,18 @@ bool Arch::is_lab_ctrlset_legal(uint32_t lab) const
void Arch::lab_pre_route()
{
log_info("Preparing LABs for routing...\n");
int labs_used = 0;
for (uint32_t lab = 0; lab < labs.size(); lab++) {
bool lab_used = false;
assign_control_sets(lab);
for (uint8_t alm = 0; alm < 10; alm++) {
reassign_alm_inputs(lab, alm);
lab_used |= labs.at(lab).alms.at(alm).unique_input_count > 0;
}
if (lab_used)
labs_used++;
}
log_info(" %d LABs used\n", labs_used);
}

void Arch::assign_control_sets(uint32_t lab)
Expand Down