spot/src/misc/intvcmp2.cc
Alexandre Duret-Lutz 0689aa165b silence diagnostics from gcc-snapshot
(Upcoming GCC 6.)

* src/misc/intvcmp2.cc: Here.
* NEWS: Mention it.
2015-08-17 18:56:36 +02:00

551 lines
14 KiB
C++

// -*- coding: utf-8 -*-
// Copyright (C) 2011, 2013, 2014, 2015 Laboratoire de Recherche et
// Développement de l'Epita (LRDE).
//
// This file is part of Spot, a model checking library.
//
// Spot is free software; you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// Spot is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
// License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#include "config.h"
#include "common.hh"
#include <cstddef>
#include <cassert>
#include "intvcmp2.hh"
namespace spot
{
namespace
{
// This implements integer compression inspired from "Simple-9".
//
// The first bits of an integer tell how the rest of the integer is coded:
// 00: 30 1-bit values id=0
// 01: 10 3-bit values id=1
// 10: 6 5-bit values id=2
// 1100: 4 7-bit values id=3
// 1101: 3 9-bit values (1 bit lost) id=4
// 1110: 2 14-bit values id=5
// 1111: 1 28-bit value id=6
template <class Self>
class stream_compression_base
{
public:
stream_compression_base(size_t size)
: size_(size)
{
}
void run()
{
static const unsigned bits_width[7] = { 1, 3, 5, 7, 9, 14, 28 };
static const unsigned max_count[8] = { 30, 10, 6, 4, 3, 2, 1, 0 };
static const unsigned max_allowed[8] = { 1,
(1 << 3) - 1,
(1 << 5) - 1,
(1 << 7) - 1,
(1 << 9) - 1,
(1 << 14) - 1,
(1 << 28) - 1,
-1U };
// If we have only X data to compress and they fit with the
// current bit width, the following table tells us we should
// use bits_width[count_to_level[X - 1]] to limit the number
// of trailing zeros we encode. E.g. count_to_level[5 - 1]
// is 2, which mean that 5 values should be encoded with
// bits_width[2] == 5 bits.
static const unsigned count_to_level[30] =
{
6, // 1
5, // 2
4, // 3
3, // 4
2, // 5
2, // 6
1, // 7
1, // 8
1, // 9
1, // 10
0, 0, 0, 0, 0, // 11-15
0, 0, 0, 0, 0, // 16-20
0, 0, 0, 0, 0, // 21-25
0, 0, 0, 0, 0, // 26-30
};
while (size_ > 0)
{
unsigned id = 0; // Current level in the above two tables.
unsigned curmax_allowed = max_allowed[id];
unsigned compressable = 0; // Number of integers ready to pack.
do
{
unsigned int val = self().data_at(compressable);
++compressable;
while (val > curmax_allowed)
{
curmax_allowed = max_allowed[++id];
if (compressable > max_count[id])
goto fast_encode;
}
if (compressable >= max_count[id])
goto fast_encode;
}
while (SPOT_LIKELY(compressable < size_));
assert(compressable < max_count[id]);
// Since we have less data than the current "id" allows,
// try to use more bits so we can encode faster.
id = count_to_level[compressable - 1];
if (compressable == max_count[id])
goto fast_encode;
// Slow compression for situations where we have
// compressable < max_count[id]. We can only be in
// one of the 3 first "id" (1, 3, or 5 bits);
{
assert(id <= 2);
unsigned bits = bits_width[id];
unsigned finalshifts = (max_count[id] - compressable) * bits;
size_t pos = 0;
unsigned output = self().data_at(pos);
while (--compressable)
{
output <<= bits;
output += self().data_at(++pos);
}
output <<= finalshifts;
output += id << 30;
self().push_data(output);
return;
}
fast_encode:
switch (id)
{
case 0: // 30 1-bit values
{
// This code has been tuned so that the compiler can
// efficiently encode it as a series of MOV+LEA
// instructions, without shifts. For instance
//
// output <<= 1;
// output += self().data_at(4);
//
// translates to (assuming %eax points to the input,
// and %edx holds the output) the following:
//
// mov ecx, [eax+16]
// lea edx, [ecx+edx*2]
//
// This optimization is the reason why we use 'output +='
// instead of the more intuitive 'output |=' everywhere in
// this file.
unsigned int output = 0x00 << 1; // 00
output += self().data_at(0);
output <<= 1;
output += self().data_at(1);
output <<= 1;
output += self().data_at(2);
output <<= 1;
output += self().data_at(3);
output <<= 1;
output += self().data_at(4);
output <<= 1;
output += self().data_at(5);
output <<= 1;
output += self().data_at(6);
output <<= 1;
output += self().data_at(7);
output <<= 1;
output += self().data_at(8);
output <<= 1;
output += self().data_at(9);
output <<= 1;
output += self().data_at(10);
output <<= 1;
output += self().data_at(11);
output <<= 1;
output += self().data_at(12);
output <<= 1;
output += self().data_at(13);
output <<= 1;
output += self().data_at(14);
output <<= 1;
output += self().data_at(15);
output <<= 1;
output += self().data_at(16);
output <<= 1;
output += self().data_at(17);
output <<= 1;
output += self().data_at(18);
output <<= 1;
output += self().data_at(19);
output <<= 1;
output += self().data_at(20);
output <<= 1;
output += self().data_at(21);
output <<= 1;
output += self().data_at(22);
output <<= 1;
output += self().data_at(23);
output <<= 1;
output += self().data_at(24);
output <<= 1;
output += self().data_at(25);
output <<= 1;
output += self().data_at(26);
output <<= 1;
output += self().data_at(27);
output <<= 1;
output += self().data_at(28);
output <<= 1;
output += self().data_at(29);
self().push_data(output);
}
break;
case 1: // 10 3-bit values
{
// This code has been tuned so that the compiler can
// efficiently encode it as a series of MOV+LEA
// instructions, without shifts. For instance
//
// output <<= 3;
// output += self().data_at(4);
//
// translates to (assuming %eax points to the input,
// and %edx holds the output) the following:
//
// mov ecx, [eax+16]
// lea edx, [ecx+edx*8]
unsigned int output = 0x01 << 3; // 01
output += self().data_at(0);
output <<= 3;
output += self().data_at(1);
output <<= 3;
output += self().data_at(2);
output <<= 3;
output += self().data_at(3);
output <<= 3;
output += self().data_at(4);
output <<= 3;
output += self().data_at(5);
output <<= 3;
output += self().data_at(6);
output <<= 3;
output += self().data_at(7);
output <<= 3;
output += self().data_at(8);
output <<= 3;
output += self().data_at(9);
self().push_data(output);
}
break;
case 2: // 6 5-bit values
{
unsigned int output = 0x02U << 30; // 10
output += self().data_at(0) << 25;
output += self().data_at(1) << 20;
output += self().data_at(2) << 15;
output += self().data_at(3) << 10;
output += self().data_at(4) << 5;
output += self().data_at(5);
self().push_data(output);
}
break;
case 3: // 4 7-bit values
{
unsigned int output = 0x0CU << 28; // 1100
output += self().data_at(0) << 21;
output += self().data_at(1) << 14;
output += self().data_at(2) << 7;
output += self().data_at(3);
self().push_data(output);
}
break;
case 4: // 3 9-bit values
{
unsigned int output = 0x0DU << 28; // 1101x (1 bit lost)
output += self().data_at(0) << 18;
output += self().data_at(1) << 9;
output += self().data_at(2);
self().push_data(output);
}
break;
case 5: // 2 14-bit values
{
unsigned int output = 0x0EU << 28; // 1110
output += self().data_at(0) << 14;
output += self().data_at(1);
self().push_data(output);
}
break;
case 6: // one 28-bit value
{
unsigned int output = 0x0FU << 28; // 1111
output += self().data_at(0);
self().push_data(output);
}
break;
}
self().forward(max_count[id]);
size_ -= max_count[id];
}
}
protected:
size_t size_;
Self& self()
{
return static_cast<Self&>(*this);
}
const Self& self() const
{
return static_cast<const Self&>(*this);
}
};
class int_array_array_compression:
public stream_compression_base<int_array_array_compression>
{
public:
int_array_array_compression(const int* array, size_t n,
int* dest, size_t& dest_n)
: stream_compression_base<int_array_array_compression>(n),
array_(array), result_size_(dest_n),
result_(dest), result_end_(dest + dest_n)
{
result_size_ = 0; // this resets dest_n.
}
void push_data(unsigned int i)
{
assert(result_ < result_end_);
++result_size_;
*result_++ = static_cast<int>(i);
}
unsigned int data_at(size_t offset)
{
return static_cast<unsigned int>(array_[offset]);
}
void forward(size_t offset)
{
array_ += offset;
}
protected:
const int* array_;
size_t& result_size_;
int* result_;
int* result_end_;
};
} // anonymous
void
int_array_array_compress2(const int* array, size_t n,
int* dest, size_t& dest_size)
{
int_array_array_compression c(array, n, dest, dest_size);
c.run();
}
namespace
{
template<class Self>
class stream_decompression_base
{
public:
void run()
{
while (SPOT_LIKELY(self().have_comp_data()))
{
unsigned val = self().next_comp_data();
unsigned id = val >> 28;
switch (id)
{
case 0x00: // 00xx - 30 1-bit values.
case 0x01:
case 0x02:
case 0x03:
self().write_data_at(0, !!(val & (1 << 29)));
self().write_data_at(1, !!(val & (1 << 28)));
self().write_data_at(2, !!(val & (1 << 27)));
self().write_data_at(3, !!(val & (1 << 26)));
self().write_data_at(4, !!(val & (1 << 25)));
self().write_data_at(5, !!(val & (1 << 24)));
self().write_data_at(6, !!(val & (1 << 23)));
self().write_data_at(7, !!(val & (1 << 22)));
self().write_data_at(8, !!(val & (1 << 21)));
self().write_data_at(9, !!(val & (1 << 20)));
self().write_data_at(10, !!(val & (1 << 19)));
self().write_data_at(11, !!(val & (1 << 18)));
self().write_data_at(12, !!(val & (1 << 17)));
self().write_data_at(13, !!(val & (1 << 16)));
self().write_data_at(14, !!(val & (1 << 15)));
self().write_data_at(15, !!(val & (1 << 14)));
self().write_data_at(16, !!(val & (1 << 13)));
self().write_data_at(17, !!(val & (1 << 12)));
self().write_data_at(18, !!(val & (1 << 11)));
self().write_data_at(19, !!(val & (1 << 10)));
self().write_data_at(20, !!(val & (1 << 9)));
self().write_data_at(21, !!(val & (1 << 8)));
self().write_data_at(22, !!(val & (1 << 7)));
self().write_data_at(23, !!(val & (1 << 6)));
self().write_data_at(24, !!(val & (1 << 5)));
self().write_data_at(25, !!(val & (1 << 4)));
self().write_data_at(26, !!(val & (1 << 3)));
self().write_data_at(27, !!(val & (1 << 2)));
self().write_data_at(28, !!(val & (1 << 1)));
self().write_data_at(29, !!(val & (1 << 0)));
self().forward(30);
break;
case 0x04: // 01xx - 10 3-bit values.
case 0x05:
case 0x06:
case 0x07:
self().write_data_at(0, (val >> 27) & 0x07);
self().write_data_at(1, (val >> 24) & 0x07);
self().write_data_at(2, (val >> 21) & 0x07);
self().write_data_at(3, (val >> 18) & 0x07);
self().write_data_at(4, (val >> 15) & 0x07);
self().write_data_at(5, (val >> 12) & 0x07);
self().write_data_at(6, (val >> 9) & 0x07);
self().write_data_at(7, (val >> 6) & 0x07);
self().write_data_at(8, (val >> 3) & 0x07);
self().write_data_at(9, (val >> 0) & 0x07);
self().forward(10);
break;
case 0x08: // 10xx - 6 5-bit values.
case 0x09:
case 0x0A:
case 0x0B:
self().write_data_at(0, (val >> 25) & 0x1F);
self().write_data_at(1, (val >> 20) & 0x1F);
self().write_data_at(2, (val >> 15) & 0x1F);
self().write_data_at(3, (val >> 10) & 0x1F);
self().write_data_at(4, (val >> 5) & 0x1F);
self().write_data_at(5, (val >> 0) & 0x1F);
self().forward(6);
break;
case 0x0C: // 1100 - 4 7-bit values
self().write_data_at(0, (val >> 21) & 0x7F);
self().write_data_at(1, (val >> 14) & 0x7F);
self().write_data_at(2, (val >> 7) & 0x7F);
self().write_data_at(3, (val >> 0) & 0x7F);
self().forward(4);
break;
case 0x0D: // 1101x - 3 9-bit values.
self().write_data_at(0, (val >> 18) & 0x1FF);
self().write_data_at(1, (val >> 9) & 0x1FF);
self().write_data_at(2, (val >> 0) & 0x1FF);
self().forward(3);
break;
case 0x0E: // 110x - 2 14-bit values.
self().write_data_at(0, (val >> 14) & 0x3FFF);
self().write_data_at(1, (val >> 0) & 0x3FFF);
self().forward(2);
break;
case 0x0F: // 1100 - 1 28-bit value.
self().write_data_at(0, val & 0xFFFFFFF);
self().forward(1);
break;
}
}
}
protected:
Self& self()
{
return static_cast<Self&>(*this);
}
const Self& self() const
{
return static_cast<const Self&>(*this);
}
};
class int_array_array_decompression:
public stream_decompression_base<int_array_array_decompression>
{
public:
int_array_array_decompression(const int* array,
size_t array_size,
int* res)
: array_(array), n_(array_size), pos_(0), result_(res)
{
}
void write_data_at(size_t pos, unsigned int i)
{
result_[pos] = i;
}
void forward(size_t i)
{
result_ += i;
}
bool have_comp_data() const
{
return pos_ < n_;
}
unsigned int next_comp_data()
{
return array_[pos_++];
}
protected:
const int* array_;
size_t n_;
size_t pos_;
int* result_;
};
}
void
int_array_array_decompress2(const int* array, size_t array_size, int* res,
size_t)
{
int_array_array_decompression c(array, array_size, res);
c.run();
}
} // spot