ng_violet: make calcSplitRatio operation faster

Implements count_reachable in a less malloc-happy way, improving
compile performance. Adds a count() function to small_color_map.
This commit is contained in:
Justin Viiret 2017-06-06 14:37:18 +10:00 committed by Chang, Harry
parent cadc7028b1
commit 08bf909e2b
2 changed files with 36 additions and 9 deletions

View File

@ -1,5 +1,5 @@
/*
* Copyright (c) 2016-2017, Intel Corporation
* Copyright (c) 2016-2018, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@ -60,6 +60,7 @@
#include "util/flat_containers.h"
#include "util/graph.h"
#include "util/graph_range.h"
#include "util/graph_small_color_map.h"
#include "util/insertion_ordered.h"
#include "util/make_unique.h"
#include "util/order_check.h"
@ -133,14 +134,21 @@ bool createsTransientLHS(const NGHolder &g, const vector<NFAVertex> &vv,
return true;
}
/**
* Counts the number of vertices that are reachable from the set of sources
* given.
*/
static
double calcSplitRatio(const NGHolder &g, const vector<NFAVertex> &vv) {
flat_set<NFAVertex> not_reachable;
find_unreachable(g, vv, &not_reachable);
double rv = (double)not_reachable.size() / num_vertices(g);
rv = rv > 0.5 ? 1 - rv : rv;
size_t count_reachable(const NGHolder &g, const vector<NFAVertex> &sources,
small_color_map<decltype(get(vertex_index, g))> &color_map) {
auto null_visitor = boost::make_dfs_visitor(boost::null_visitor());
color_map.fill(small_color::white);
return rv;
for (auto v : sources) {
boost::depth_first_visit(g, v, null_visitor, color_map);
}
return color_map.count(small_color::black);
}
static
@ -687,8 +695,12 @@ unique_ptr<VertLitInfo> findBestSplit(const NGHolder &g,
}
if (last_chance) {
const size_t num_verts = num_vertices(g);
auto color_map = make_small_color_map(g);
for (auto &a : lits) {
a->split_ratio = calcSplitRatio(g, a->vv);
size_t num_reachable = count_reachable(g, a->vv, color_map);
double ratio = (double)num_reachable / (double)num_verts;
a->split_ratio = ratio > 0.5 ? 1 - ratio : ratio;
}
}

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@ -1,5 +1,5 @@
/*
* Copyright (c) 2017, Intel Corporation
* Copyright (c) 2017-2018, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@ -114,6 +114,21 @@ public:
std::memset(data->data(), val, data->size());
}
size_t count(small_color color) const {
assert(static_cast<u8>(color) < sizeof(fill_lut));
size_t num = 0;
for (size_t i = 0; i < n; i++) {
size_t byte = i / entries_per_byte;
assert(byte < data->size());
size_t bit = (i % entries_per_byte) * bit_size;
u8 val = ((*data)[byte] >> bit) & bit_mask;
if (static_cast<small_color>(val) == color) {
num++;
}
}
return num;
}
small_color get_impl(key_type key) const {
auto i = get(index_map, key);
assert(i < n);