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Himbaechel xilinx : DSP packing : Disable clustering

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Adrien Prost-Boucle 2024-09-19 10:54:55 +02:00 committed by myrtle
parent 8a0e062520
commit 81bf92a855
1 changed files with 6 additions and 0 deletions
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6
himbaechel/uarch/xilinx/pack_dsp_xc7.cc
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@ -81,6 +81,8 @@ void XC7Packer::walk_dsp(CellInfo *root, CellInfo *current_cell, int constr_z)
// the connected cell has to be above the current cell,
// otherwise it cannot be routed, because the cascading ports
// are only connected to the DSP above
// FIXME The offset +/-5 applies to DSP tiles, not to DSP slices
// So two cascaded DSPs can be placed in one tile, which does not correspond to a +/-5 offset
auto previous_y = (current_cell == root) ? 0 : current_cell->constr_y;
cascaded_cell->constr_y = previous_y + (is_lower_bel ? -5 : 0);
cascaded_cell->constr_z = constr_z;
@ -169,11 +171,15 @@ void XC7Packer::pack_dsps()
}
}
// Creating placement clusters is currently disabled, because the current constraints
// on Y coordinates don't always correspond to placement possibilities, which makes placer crash
#if 0
for (auto root : dsp_roots) {
root->constr_abs_z = true;
root->constr_z = BEL_LOWER_DSP;
walk_dsp(root, root, BEL_UPPER_DSP);
}
#endif
}
NEXTPNR_NAMESPACE_END