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Simplify zero

This commit is contained in:
Miodrag Milanovic 2025-06-30 16:32:08 +02:00
parent 6dc5d8c98a
commit 9ea60d1c8f
1 changed files with 20 additions and 28 deletions
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48
himbaechel/uarch/gatemate/pack_mult.cc
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@ -148,17 +148,9 @@ struct Multiplier
ZeroDriver::ZeroDriver(CellInfo *lower, CellInfo *upper, IdString name) : lower{lower}, upper{upper}
{
lower->params[id_INIT_L02] = Property(LUT_ZERO, 4); // (unused)
lower->params[id_INIT_L03] = Property(LUT_ZERO, 4); // (unused)
lower->params[id_INIT_L11] = Property(LUT_ZERO, 4); // (unused)
lower->params[id_INIT_L20] = Property(LUT_ZERO, 4); // (unused)
upper->params[id_INIT_L00] = Property(LUT_ZERO, 4); // (unused)
upper->params[id_INIT_L01] = Property(LUT_ZERO, 4); // (unused)
upper->params[id_INIT_L10] = Property(LUT_ZERO, 4); // (unused)
upper->params[id_C_O1] = Property(0b11, 2); // COMB1OUT -> OUT1
upper->params[id_C_O2] = Property(0b11, 2); // COMB2OUT -> OUT2
}
APassThroughCell::APassThroughCell(CellInfo *lower, CellInfo *upper, IdString name, bool inverted)
@ -416,8 +408,8 @@ void GateMatePacker::pack_mult()
// fpga_generic.pas in p_r might have useful info
auto create_zero_driver = [&](IdString name) {
auto *zero_lower = create_cell_ptr(id_CPE_LT_L, ctx->idf("%s$zero_lower", name.c_str(ctx)));
auto *zero_upper = create_cell_ptr(id_CPE_LT_U, ctx->idf("%s$zero_upper", name.c_str(ctx)));
auto *zero_lower = create_cell_ptr(id_CPE_DUMMY, ctx->idf("%s$zero_lower", name.c_str(ctx)));
auto *zero_upper = create_cell_ptr(id_CPE_L2T4, ctx->idf("%s$zero", name.c_str(ctx)));
return ZeroDriver{zero_lower, zero_upper, name};
};
@ -519,7 +511,7 @@ void GateMatePacker::pack_mult()
auto *root = m.cols[0].b_passthru.upper;
root->cluster = root->name;
auto constrain_cell = [&](CellInfo *cell, int x_offset, int y_offset) {
auto constrain_cell = [&](CellInfo *cell, int x_offset, int y_offset, int z_offset) {
if (cell == root)
return;
root->constr_children.push_back(cell);
@ -527,42 +519,42 @@ void GateMatePacker::pack_mult()
cell->constr_abs_z = true;
cell->constr_x = x_offset;
cell->constr_y = y_offset;
cell->constr_z = cell->type == id_CPE_LT_L ? 1 : 0;
cell->constr_z = z_offset;
};
// Constrain zero driver.
constrain_cell(m.zero.lower, -1, 3);
constrain_cell(m.zero.upper, -1, 3);
constrain_cell(m.zero.lower, -1, 3, 1);
constrain_cell(m.zero.upper, -1, 3, 0);
// Constrain A passthrough cells.
for (int a = 0; a < a_width / 2; a++) {
auto &a_passthru = m.a_passthrus.at(a);
constrain_cell(a_passthru.lower, -1, 4 + a);
constrain_cell(a_passthru.upper, -1, 4 + a);
constrain_cell(a_passthru.lower, -1, 4 + a, 1);
constrain_cell(a_passthru.upper, -1, 4 + a, 0);
}
// Constrain multiplier columns.
for (int b = 0; b < b_width / 2; b++) {
auto &col = m.cols.at(b);
constrain_cell(col.b_passthru.lower, b, b);
constrain_cell(col.b_passthru.upper, b, b);
constrain_cell(col.b_passthru.lower, b, b, 1);
constrain_cell(col.b_passthru.upper, b, b, 0);
constrain_cell(col.carry.lower, b, b + 1);
constrain_cell(col.carry.upper, b, b + 1);
constrain_cell(col.carry.lower, b, b + 1, 1);
constrain_cell(col.carry.upper, b, b + 1, 0);
constrain_cell(col.multfab.lower, b, b + 2);
constrain_cell(col.multfab.upper, b, b + 2);
constrain_cell(col.multfab.lower, b, b + 2, 1);
constrain_cell(col.multfab.upper, b, b + 2, 0);
constrain_cell(col.f_route.lower, b, b + 3);
constrain_cell(col.f_route.upper, b, b + 3);
constrain_cell(col.f_route.lower, b, b + 3, 1);
constrain_cell(col.f_route.upper, b, b + 3, 0);
for (size_t mult_idx = 0; mult_idx < col.mults.size(); mult_idx++) {
constrain_cell(col.mults[mult_idx].lower, b, b + 4 + mult_idx);
constrain_cell(col.mults[mult_idx].upper, b, b + 4 + mult_idx);
constrain_cell(col.mults[mult_idx].lower, b, b + 4 + mult_idx, 1);
constrain_cell(col.mults[mult_idx].upper, b, b + 4 + mult_idx, 0);
}
constrain_cell(col.msb_route.lower, b, b + 4 + col.mults.size());
constrain_cell(col.msb_route.upper, b, b + 4 + col.mults.size());
constrain_cell(col.msb_route.lower, b, b + 4 + col.mults.size(), 1);
constrain_cell(col.msb_route.upper, b, b + 4 + col.mults.size(), 0);
}
// Step 3: connect them.