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booth: Move up signed quadrant 1 logic

This commit is contained in:
Martin Povišer 2023-11-06 14:24:10 +01:00
parent 8d33cc2fb6
commit d8408b2350
1 changed files with 17 additions and 24 deletions
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41
passes/techmap/booth.cc
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@ -1027,6 +1027,22 @@ struct BoothPassWorker {
PPij[((encoder_ix - 1) * dec_count) + dec_count - 1], unused_op);
}
//
// instantiate the quadrant 1 cell. This is the upper right
// quadrant which can be realized using non-booth encoded logic.
//
SigBit pp0_o_int, pp1_o_int, nxj_o_int, q1_carry_out;
BuildBoothQ1("icb_booth_q1_",
negi_n_int[0], // negi
cori_n_int[0], // cori
X[0], X[1], Y[0], Y[1],
nxj_o_int, q1_carry_out, pp0_o_int, pp1_o_int);
module->connect(Z[0], pp0_o_int);
module->connect(Z[1], pp1_o_int);
module->connect(nxj[(0 * dec_count) + 2], nxj_o_int);
//
// sum up the partial products
//
@ -1052,6 +1068,7 @@ struct BoothPassWorker {
/* X */ fa_carry[0].extract(2, x_sz + 2),
/* Y */ fa_sum[0].extract(2, x_sz + 2)
);
module->connect(fa_carry[0][1], q1_carry_out);
// step case: 2nd and rest of rows. (fa_row_ix == 1...n)
// special because these are driven by a decoder and prior fa.
@ -1093,30 +1110,6 @@ struct BoothPassWorker {
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);
}
//
// instantiate the quadrant 1 cell. This is the upper right
// quadrant which can be realized using non-booth encoded logic.
//
std::string q1_name = "icb_booth_q1_";
SigBit pp0_o_int;
SigBit pp1_o_int;
SigBit nxj_o_int;
SigBit cor_o_int;
BuildBoothQ1(q1_name,
negi_n_int[0], // negi
cori_n_int[0], // cori
X[0], X[1], Y[0], Y[1],
nxj_o_int, cor_o_int, pp0_o_int, pp1_o_int);
module->connect(fa_sum[0][0], pp0_o_int);
module->connect(fa_sum[0][1], pp1_o_int);
module->connect(fa_carry[0][1], cor_o_int);
module->connect(nxj[(0 * dec_count) + 2], nxj_o_int);
}
};