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booth: Refactor signed CPA

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This commit is contained in:
Martin Povišer 2023-11-06 14:18:47 +01:00
parent 00e899f98d
commit 8d33cc2fb6
1 changed files with 17 additions and 31 deletions
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48
passes/techmap/booth.cc
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@ -1072,40 +1072,26 @@ struct BoothPassWorker {
// instantiate the cpa
SigSpec cpa_carry;
if (z_sz > fa_row_count * 2)
cpa_carry = module->addWire(NEW_ID_SUFFIX("cpa_carry"), z_sz - fa_row_count * 2);
for (int cix = 0; cix < z_sz; cix++)
cpa_carry.append(module->addWire(NEW_ID_SUFFIX(stringf("cpa_carry_%d", cix)), 1));
// The end case where we pass the last two summands
// from prior row directly to product output
// without using a cpa cell. This is always
// 0,1 index of prior fa row
for (int cpa_ix = 0; cpa_ix < fa_row_count * 2; cpa_ix += 2) {
int fa_row_ix = cpa_ix / 2;
module->connect(Z.extract(cpa_ix, 2), fa_sum[fa_row_ix].extract(0, 2));
}
for (int cpa_ix = 0; cpa_ix < z_sz; cpa_ix++) {
// The end case where we pass the last two summands
// from prior row directly to product output
// without using a cpa cell. This is always
// 0,1 index of prior fa row
if (cpa_ix <= fa_row_count * 2 - 1) {
int fa_row_ix = cpa_ix / 2;
for (int cpa_ix = fa_row_count * 2; cpa_ix < z_sz; cpa_ix++) {
int offset = fa_row_count * 2;
std::string cpa_name = stringf("cpa_%d", cpa_ix - offset);
module->addBufGate(NEW_ID_SUFFIX(stringf("pp_buf_%d_driven_by_fa_row_%d", cpa_ix, fa_row_ix)),
fa_sum[fa_row_ix][0], Z[cpa_ix]);
cpa_ix++;
module->addBufGate(NEW_ID_SUFFIX(stringf("pp_buf_%d_driven_by_fa_row_%d", cpa_ix, fa_row_ix)),
fa_sum[fa_row_ix][1], Z[cpa_ix]);
} else {
int offset = fa_row_count * 2;
bool base_case = cpa_ix - offset == 0 ? true : false;
std::string cpa_name = stringf("cpa_%d", cpa_ix - offset);
SigBit ci;
if (base_case)
ci = cori_n_int[enc_count - 1];
else
ci = cpa_carry[cpa_ix - offset - 1];
SigBit op;
BuildHa(cpa_name, fa_sum[fa_row_count - 1][cpa_ix - offset + 2], ci, op,
cpa_carry[cpa_ix - offset]);
module->connect(Z[cpa_ix], op);
}
SigBit ci = (cpa_ix == offset) ? cori_n_int[enc_count - 1] : cpa_carry[cpa_ix - offset - 1];
SigBit op;
BuildHa(cpa_name, fa_sum[fa_row_count - 1][cpa_ix - offset + 2], ci, op, cpa_carry[cpa_ix - offset]);
module->connect(Z[cpa_ix], op);
}
//