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turbonss/cxxmph/mph_table.cc

194 lines
6.4 KiB
C++

#include <limits>
#include <iostream>
#include <vector>
using std::cerr;
using std::endl;
#include "mph_table.h"
using std::vector;
namespace {
static const uint8_t kUnassigned = 3;
// table used for looking up the number of assigned vertices to a 8-bit integer
static uint8_t kBdzLookupTable[] =
{
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 2, 2, 2, 1,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 2, 2, 2, 1,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
4, 4, 4, 3, 4, 4, 4, 3, 4, 4, 4, 3, 3, 3, 3, 2,
3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 2, 2, 2, 1,
3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 2, 2, 2, 1,
3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 2, 2, 2, 1,
3, 3, 3, 2, 3, 3, 3, 2, 3, 3, 3, 2, 2, 2, 2, 1,
2, 2, 2, 1, 2, 2, 2, 1, 2, 2, 2, 1, 1, 1, 1, 0
};
} // anonymous namespace
namespace cxxmph {
const uint8_t MPHTable::valuemask[] = { 0xfc, 0xf3, 0xcf, 0x3f};
void MPHTable::clear() {
// TODO(davi) impolement me
}
bool MPHTable::GenerateQueue(
TriGraph* graph, vector<uint32_t>* queue_output) {
uint32_t queue_head = 0, queue_tail = 0;
uint32_t nedges = m_;
uint32_t nvertices = n_;
// Relies on vector<bool> using 1 bit per element
vector<bool> marked_edge(nedges + 1, false);
vector<uint32_t> queue(nvertices, 0);
for (uint32_t i = 0; i < nedges; ++i) {
const TriGraph::Edge& e = graph->edges()[i];
if (graph->vertex_degree()[e[0]] == 1 ||
graph->vertex_degree()[e[1]] == 1 ||
graph->vertex_degree()[e[2]] == 1) {
if (!marked_edge[i]) {
queue[queue_head++] = i;
marked_edge[i] = true;
}
}
}
/*
for (unsigned int i = 0; i < marked_edge.size(); ++i) {
cerr << "vertex with degree " << static_cast<uint32_t>(graph->vertex_degree()[i]) << " marked " << marked_edge[i] << endl;
}
for (unsigned int i = 0; i < queue.size(); ++i) {
cerr << "vertex " << i << " queued at " << queue[i] << endl;
}
*/
// At this point queue head is the number of edges touching at least one
// vertex of degree 1.
// cerr << "Queue head " << queue_head << " Queue tail " << queue_tail << endl;
// graph->DebugGraph();
while (queue_tail != queue_head) {
uint32_t current_edge = queue[queue_tail++];
graph->RemoveEdge(current_edge);
const TriGraph::Edge& e = graph->edges()[current_edge];
for (int i = 0; i < 3; ++i) {
uint32_t v = e[i];
if (graph->vertex_degree()[v] == 1) {
uint32_t first_edge = graph->first_edge()[v];
if (!marked_edge[first_edge]) {
queue[queue_head++] = first_edge;
marked_edge[first_edge] = true;
}
}
}
}
/*
for (unsigned int i = 0; i < queue.size(); ++i) {
cerr << "vertex " << i << " queued at " << queue[i] << endl;
}
*/
int cycles = queue_head - nedges;
if (cycles == 0) queue.swap(*queue_output);
return cycles == 0;
}
void MPHTable::Assigning(
const vector<TriGraph::Edge>& edges, const vector<uint32_t>& queue) {
uint32_t current_edge = 0;
vector<bool> marked_vertices(n_ + 1);
// Initialize vector of half nibbles with all bits set.
uint32_t sizeg = static_cast<uint32_t>(ceil(n_/4.0));
vector<uint8_t>(sizeg, std::numeric_limits<uint8_t>::max()).swap(g_);
uint32_t nedges = m_; // for legibility
for (int i = nedges - 1; i + 1 >= 1; --i) {
current_edge = queue[i];
const TriGraph::Edge& e = edges[current_edge];
// cerr << "B: " << e[0] << " " << e[1] << " " << e[2] << " -> "
// << get_2bit_value(g_, e[0]) << " "
// << get_2bit_value(g_, e[1]) << " "
// << get_2bit_value(g_, e[2]) << " edge " << current_edge << endl;
if (!marked_vertices[e[0]]) {
if (!marked_vertices[e[1]]) {
set_2bit_value(&g_, e[1], kUnassigned);
marked_vertices[e[1]] = true;
}
if (!marked_vertices[e[2]]) {
set_2bit_value(&g_, e[2], kUnassigned);
assert(marked_vertices.size() > e[2]);
marked_vertices[e[2]] = true;
}
set_2bit_value(&g_, e[0], (6 - (get_2bit_value(g_, e[1]) + get_2bit_value(g_, e[2]))) % 3);
marked_vertices[e[0]] = true;
} else if (!marked_vertices[e[1]]) {
if (!marked_vertices[e[2]]) {
set_2bit_value(&g_, e[2], kUnassigned);
marked_vertices[e[2]] = true;
}
set_2bit_value(&g_, e[1], (7 - (get_2bit_value(g_, e[0]) + get_2bit_value(g_, e[2]))) % 3);
marked_vertices[e[1]] = true;
} else {
set_2bit_value(&g_, e[2], (8 - (get_2bit_value(g_, e[0]) + get_2bit_value(g_, e[1]))) % 3);
marked_vertices[e[2]] = true;
}
// cerr << "A: " << e[0] << " " << e[1] << " " << e[2] << " -> "
// << get_2bit_value(g_, e[0]) << " "
// << get_2bit_value(g_, e[1]) << " "
// << get_2bit_value(g_, e[2]) << " " << endl;
}
}
void MPHTable::Ranking() {
uint32_t nbytes_total = static_cast<uint32_t>(ceil(n_ / 4.0));
uint32_t size = k_ >> 2U;
uint32_t ranktablesize = static_cast<uint32_t>(
ceil(n_ / static_cast<double>(k_)));
// TODO(davi) Change swap of member classes for resize + memset to avoid
// fragmentation
vector<uint32_t> (ranktablesize).swap(ranktable_);;
uint32_t offset = 0;
uint32_t count = 0;
uint32_t i = 1;
while (1) {
if (i == ranktable_.size()) break;
uint32_t nbytes = size < nbytes_total ? size : nbytes_total;
for (uint32_t j = 0; j < nbytes; ++j) count += kBdzLookupTable[g_[offset + j]];
ranktable_[i] = count;
offset += nbytes;
nbytes_total -= size;
++i;
}
}
uint32_t MPHTable::Rank(uint32_t vertex) const {
uint32_t index = vertex >> b_;
uint32_t base_rank = ranktable_[index];
uint32_t beg_idx_v = index << b_;
uint32_t beg_idx_b = beg_idx_v >> 2;
uint32_t end_idx_b = vertex >> 2;
while (beg_idx_b < end_idx_b) base_rank += kBdzLookupTable[g_[beg_idx_b++]];
beg_idx_v = beg_idx_b << 2;
// cerr << "beg_idx_v: " << beg_idx_v << endl;
// cerr << "base rank: " << base_rank << endl;
//cerr << "G: ";
// for (unsigned int i = 0; i < n_; ++i) {
// cerr << get_2bit_value(g_, i) << " ";
//}
// cerr << endl;
while (beg_idx_v < vertex) {
if (get_2bit_value(g_, beg_idx_v) != kUnassigned) ++base_rank;
++beg_idx_v;
}
// cerr << "Base rank: " << base_rank << endl;
return base_rank;
}
} // namespace cxxmph