OpenFPGA/openfpga/src/base/openfpga_lut_truth_table_fi...

187 lines
6.9 KiB
C++

/********************************************************************
* This file includes functions to fix up the pb pin mapping results
* after routing optimization
*******************************************************************/
/* Headers from vtrutil library */
#include "vtr_assert.h"
#include "vtr_log.h"
#include "vtr_time.h"
/* Headers from vpr library */
#include "lut_utils.h"
#include "openfpga_lut_truth_table_fixup.h"
#include "pb_type_utils.h"
#include "vpr_utils.h"
/* Include global variables of VPR */
#include "globals.h"
/* begin namespace openfpga */
namespace openfpga {
/********************************************************************
* Apply the fix-up to truth table of LUT according to its pin
* rotation status by packer
*
* Note:
* - pb must represents a LUT pb in the graph and it should be primitive
*******************************************************************/
static void fix_up_lut_atom_block_truth_table(
const AtomContext& atom_ctx, t_pb* pb, const t_pb_routes& pb_route,
VprClusteringAnnotation& vpr_clustering_annotation, const bool& verbose) {
t_pb_graph_node* pb_graph_node = pb->pb_graph_node;
t_pb_type* pb_type = pb->pb_graph_node->pb_type;
VTR_ASSERT(LUT_CLASS == pb_type->class_type);
for (int iport = 0; iport < pb_type->num_ports; ++iport) {
/* We only care about input ports whose pins are equivalent */
if (IN_PORT != pb_type->ports[iport].type ||
true == pb_type->ports[iport].is_clock) {
continue;
}
if (pb_type->ports[iport].equivalent == PortEquivalence::NONE) {
continue;
}
/* Reach here, we have to apply a fix-up */
AtomBlockId atom_blk = atom_ctx.nlist.find_block(pb->name);
VTR_ASSERT(atom_blk);
/* Port exists (some LUTs may have no input and hence no port in the atom
* netlist) */
AtomPortId atom_port =
atom_ctx.nlist.find_atom_port(atom_blk, pb_type->ports[iport].model_port);
if (!atom_port) {
continue;
}
/* Find the pin rotation status and record it ,
* Note that some LUT inputs may not be used, we set them to be open by
* default
*/
std::vector<int> rotated_pin_map(pb_type->ports[iport].num_pins, -1);
for (int ipin = 0; ipin < pb_type->ports[iport].num_pins; ++ipin) {
int node_index =
pb_graph_node->input_pins[iport][ipin].pin_count_in_cluster;
if (pb_route.count(node_index)) {
/* The pin is mapped to a net, find the original pin in the atom netlist
*/
AtomNetId atom_net = pb_route[node_index].atom_net_id;
VTR_ASSERT(atom_net);
for (AtomPinId atom_pin : atom_ctx.nlist.port_pins(atom_port)) {
AtomNetId atom_pin_net = atom_ctx.nlist.pin_net(atom_pin);
if (atom_pin_net == atom_net) {
rotated_pin_map[ipin] = atom_ctx.nlist.pin_port_bit(atom_pin);
break;
}
}
}
}
/* We can apply truth table adaption now
* For unused inputs : insert dont care
* For used inputs : find the bit in the truth table rows and move it by the
* given mapping
*/
const AtomNetlist::TruthTable& orig_tt =
atom_ctx.nlist.block_truth_table(atom_blk);
const AtomNetlist::TruthTable& adapt_tt =
lut_truth_table_adaption(orig_tt, rotated_pin_map);
vpr_clustering_annotation.adapt_truth_table(pb, adapt_tt);
/* Print info is in the verbose mode */
VTR_LOGV(verbose, "Original truth table\n");
VTR_LOGV(verbose, "Index: ");
for (size_t i = 0; i < rotated_pin_map.size(); ++i) {
if (0 < i) {
VTR_LOGV(verbose, ",");
}
VTR_LOGV(verbose, "%lu", i);
}
VTR_LOGV(verbose, "\n");
for (const std::string& tt_line : truth_table_to_string(orig_tt)) {
VTR_LOGV(verbose, "\t%s\n", tt_line.c_str());
}
VTR_LOGV(verbose, "\n");
VTR_LOGV(verbose, "Pin rotation map: ");
for (size_t i = 0; i < rotated_pin_map.size(); ++i) {
if (0 < i) {
VTR_LOGV(verbose, ",");
}
if (-1 == rotated_pin_map[i]) {
VTR_LOGV(verbose, "open");
} else {
VTR_LOGV(verbose, "%lu", rotated_pin_map[i]);
}
}
VTR_LOGV(verbose, "\n");
VTR_LOGV(verbose, "Adapt truth table\n");
for (const std::string& tt_line : truth_table_to_string(adapt_tt)) {
VTR_LOGV(verbose, "\t%s\n", tt_line.c_str());
}
VTR_LOGV(verbose, "\n");
}
}
/********************************************************************
* This function recursively visits the pb graph until we reach a
* LUT pb_type (primitive node in the pb_graph with a class type
* of LUT_CLASS
* Once we find a LUT node, we will apply the fix-up
*******************************************************************/
static void rec_adapt_lut_pb_tt(
const AtomContext& atom_ctx, t_pb* pb, const t_pb_routes& pb_route,
VprClusteringAnnotation& vpr_clustering_annotation, const bool& verbose) {
t_pb_graph_node* pb_graph_node = pb->pb_graph_node;
/* If we reach a primitive pb_graph node, we return */
if (true == is_primitive_pb_type(pb_graph_node->pb_type)) {
if (LUT_CLASS == pb_graph_node->pb_type->class_type) {
/* Do fix-up here.
* Note that LUTs have two modes,
* For wire modes, we should skip the truth table adaption
* mode 0 is reserved for wire, see read_xml_arch_file.cpp
* mode 1 is the regular mode
*/
if (1 == pb->mode) {
fix_up_lut_atom_block_truth_table(atom_ctx, pb->child_pbs[0], pb_route,
vpr_clustering_annotation, verbose);
}
}
return;
}
/* Recursively visit all the used pbs in the graph */
t_mode* mapped_mode = &(pb_graph_node->pb_type->modes[pb->mode]);
for (int ipb = 0; ipb < mapped_mode->num_pb_type_children; ++ipb) {
/* Each child may exist multiple times in the hierarchy*/
for (int jpb = 0; jpb < mapped_mode->pb_type_children[ipb].num_pb; ++jpb) {
/* See if we still have any pb children to walk through */
if ((pb->child_pbs[ipb] != nullptr) &&
(pb->child_pbs[ipb][jpb].name != nullptr)) {
rec_adapt_lut_pb_tt(atom_ctx, &(pb->child_pbs[ipb][jpb]), pb_route,
vpr_clustering_annotation, verbose);
}
}
}
}
/********************************************************************
* Main function to fix up truth table for each LUT used in FPGA
* This function will walk through each clustered block
*******************************************************************/
void update_lut_tt_with_post_packing_results(
const AtomContext& atom_ctx, const ClusteringContext& clustering_ctx,
VprClusteringAnnotation& vpr_clustering_annotation, const bool& verbose) {
for (auto blk_id : clustering_ctx.clb_nlist.blocks()) {
rec_adapt_lut_pb_tt(atom_ctx, clustering_ctx.clb_nlist.block_pb(blk_id),
clustering_ctx.clb_nlist.block_pb(blk_id)->pb_route,
vpr_clustering_annotation, verbose);
}
}
} /* end namespace openfpga */