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spot/bricks/brick-bitlevel.h
Etienne Renault 458f506336 bricks: add bricks for concurrent hashmap 
* Makefile.am, README, bricks/brick-assert.h,
bricks/brick-bitlevel.h, bricks/brick-hash.h,
bricks/brick-hashset.h, bricks/brick-shmem.h,
bricks/brick-types.h, configure.ac,
debian/copyright, debian/libspot-dev.install,
m4/bricks.m4, tests/Makefile.am,
tests/core/.gitignore, tests/core/bricks.cc: here.
2020-06-03 10:33:53 +02:00

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// -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 4 -*-
/*
* Utilities and data structures for bit-level manipulation and data packing.
*/
/*
* (c) 2013-2014 Jiří Weiser <xweiser1@fi.muni.cz>
* (c) 2013 Petr Ročkai <me@mornfall.net>
*/
/* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE. */
#include <bricks/brick-assert.h>
#include <type_traits>
#ifdef __linux
#include <asm/byteorder.h>
#include <byteswap.h>
#elif !defined LITTLE_ENDIAN // if defined _WIN32
#define BYTE_ORDER 1234
#define LITTLE_ENDIAN 1234
#endif
#ifndef bswap_64
#define bswap_64 __builtin_bswap64
#endif
#include <atomic>
#include <cstring>
#ifndef BRICK_BITLEVEL_H
#define BRICK_BITLEVEL_H
namespace brick {
namespace bitlevel {
template< typename T1, typename T2 >
constexpr inline T1 align( T1 v, T2 a ) {
return (v % T1(a)) ? (v + T1(a) - (v % T1(a))) : v;
}
template< typename T1, typename T2 >
constexpr inline T1 downalign( T1 v, T2 a ) {
return v - (v % T1(a));
}
namespace compiletime {
template< typename T >
constexpr unsigned MSB( T x ) {
return x > 1 ? 1 + MSB( x >> 1 ) : 0;
}
template< typename T >
constexpr T fill( T x ) {
return x ? x | fill( x >> 1 ) : x;
}
template< typename T >
constexpr size_t sizeOf() {
return std::is_empty< T >::value ? 0 : sizeof( T );
}
}
/*
* Fills `x` by bits up to the most si significant bit.
* Comlexity is O(log n), n is sizeof(x)*8
*/
template< typename number >
static inline number fill( number x ) {
static const unsigned m = sizeof( number ) * 8;
unsigned r = 1;
if ( !x )
return 0;
while ( m != r ) {
x |= x >> r;
r <<= 1;
}
return x;
}
// get index of Most Significant Bit
// templated by argument to int, long, long long (all unsigned)
template< typename T >
static inline unsigned MSB( T x ) {
unsigned position = 0;
while ( x ) {
x >>= 1;
++position;
}
return position - 1;
}
template<>
inline unsigned MSB< unsigned int >( unsigned int x ) {
static const unsigned long bits = sizeof( unsigned int ) * 8 - 1;
return bits - __builtin_clz( x );
}
template<>
inline unsigned MSB< unsigned long >( unsigned long x ) {
static const unsigned bits = sizeof( unsigned long ) * 8 - 1;
return bits - __builtin_clzl( x );
}
template<>
inline unsigned MSB< unsigned long long >( unsigned long long x ) {
static const unsigned bits = sizeof( unsigned long long ) * 8 - 1;
return bits - __builtin_clzll( x );
}
// gets only Most Significant Bit
template< typename number >
static inline number onlyMSB( number x ) {
return number(1) << MSB( x );
}
// gets number without Most Significant Bit
template< typename number >
static inline number withoutMSB( number x ) {
return x & ~onlyMSB( x );
}
inline uint64_t bitshift( uint64_t t, int shift ) {
#if BYTE_ORDER == LITTLE_ENDIAN
return bswap_64( shift < 0 ? bswap_64( t << -shift ) : bswap_64( t >> shift ) );
#else
return shift < 0 ? ( t << -shift ) : ( t >> shift );
#endif
}
struct BitPointer {
BitPointer() : base( nullptr ), _bitoffset( 0 ) {}
template< typename T > BitPointer( T *t, int offset = 0 )
: base( static_cast< void * >( t ) ), _bitoffset( offset )
{
normalize();
}
uint32_t &word() { ASSERT( valid() ); return *static_cast< uint32_t * >( base ); }
uint64_t &dword() { ASSERT( valid() ); return *static_cast< uint64_t * >( base ); }
void normalize() {
int shift = downalign( _bitoffset, 32 );
_bitoffset -= shift;
ASSERT_EQ( shift % 8, 0 );
base = static_cast< uint32_t * >( base ) + shift / 32;
}
void shift( int bits ) { _bitoffset += bits; normalize(); }
void fromReference( BitPointer r ) { *this = r; }
int bitoffset() { return _bitoffset; }
bool valid() { return base; }
private:
void *base;
int _bitoffset;
};
inline uint64_t mask( int first, int count ) {
return bitshift(uint64_t(-1), -first) & bitshift(uint64_t(-1), (64 - first - count));
}
/*
* NB. This function will alias whatever "to" points to with an uint64_t. With
* aggressive optimisations, this might break code that passes an address of a
* variable of different type. When "to" points to a stack variable, take
* precautions to avoid breaking strict aliasing rules (the violation is not
* detected by GCC as of 4.7.3).
*/
inline void bitcopy( BitPointer from, BitPointer to, int bitcount )
{
while ( bitcount ) {
int w = std::min( 32 - from.bitoffset(), bitcount );
uint32_t fmask = mask( from.bitoffset(), w );
uint64_t tmask = mask( to.bitoffset(), w );
uint64_t bits = bitshift( from.word() & fmask, from.bitoffset() - to.bitoffset() );
ASSERT_EQ( bits & ~tmask, 0u );
ASSERT_EQ( bits & tmask, bits );
if ( to.bitoffset() + bitcount > 32 )
to.dword() = (to.dword() & ~tmask) | bits;
else
to.word() = (to.word() & ~static_cast< uint32_t >( tmask )) | static_cast< uint32_t >( bits );
from.shift( w ); to.shift( w ); bitcount -= w; // slide
}
}
template< typename T, int width = sizeof( T ) * 8 >
struct BitField
{
static const int bitwidth = width;
struct Virtual : BitPointer {
void set( T t ) { bitcopy( BitPointer( &t ), *this, bitwidth ); }
Virtual operator=( T t ) {
set( t );
return *this;
}
Virtual operator=( Virtual v ) {
set( v.get() );
return *this;
}
operator T() const { return get(); }
T get() const {
union U {
uint64_t x;
T t;
U() : t() { }
} u;
bitcopy( *this, BitPointer( &u.x ), bitwidth );
return u.t;
}
Virtual &operator++() {
T value( get() );
set( ++value );
return *this;
}
T operator++(int) {
T value( get() );
T result( value++ );
set( value );
return result;
}
Virtual &operator--() {
T value( get() );
set( --value );
return *this;
}
T operator--(int) {
T value( get() );
T result( value-- );
set( value );
return result;
}
template< typename U >
Virtual operator+=( U value ) {
T t( get() );
t += value;
set( t );
return *this;
}
template< typename U >
Virtual operator-=( U value ) {
T t( get() );
t -= value;
set( t );
return *this;
}
template< typename U >
Virtual operator*=( U value ) {
T t( get() );
t *= value;
set( t );
return *this;
}
template< typename U >
Virtual operator/=( U value ) {
T t( get() );
t /= value;
set( t );
return *this;
}
template< typename U >
Virtual operator%=( U value ) {
T t( get() );
t %= value;
set( t );
return *this;
}
};
};
struct BitLock
{
static const int bitwidth = 1;
struct Virtual : BitPointer {
using Atomic = std::atomic< uint32_t >;
Atomic &atomic() { return *reinterpret_cast< Atomic * >( &word() ); }
uint32_t bit() {
ASSERT_LEQ( bitoffset(), 31 );
return uint32_t( 1 ) << bitoffset();
}
void lock() {
uint32_t l = word();
do { l &= ~bit(); } while ( !atomic().compare_exchange_weak( l, l | bit() ) );
}
void unlock() { atomic().exchange( word() & ~bit() ); }
bool locked() { return atomic().load() & bit(); }
};
};
template< int O, typename... Args > struct BitAccess;
template< int O >
struct BitAccess< O > { static const int total = 0; };
template< int O, typename T, typename... Args >
struct BitAccess< O, T, Args... > {
static const int offset = O;
static const int width = T::bitwidth;
typedef typename T::Virtual Head;
typedef BitAccess< offset + T::bitwidth, Args... > Tail;
static const int total = width + Tail::total;
};
template< typename BA, int I >
struct _AccessAt : _AccessAt< typename BA::Tail, I - 1 > {};
template< typename BA >
struct _AccessAt< BA, 0 > { using T = BA; };
template< typename... Args >
struct _BitTuple
{
using Access = BitAccess< 0, Args... >;
static const int bitwidth = Access::total;
template< int I > using AccessAt = _AccessAt< Access, I >;
template< int I > static int offset() { return AccessAt< I >::T::offset; }
};
template< typename... Args > struct BitTuple : _BitTuple< Args... >
{
struct Virtual : BitPointer, _BitTuple< Args... > {};
char storage[ align( Virtual::bitwidth, 32 ) / 8 ];
BitTuple() { std::fill( storage, storage + sizeof( storage ), 0 ); }
operator BitPointer() { return BitPointer( storage ); }
};
template< int I, typename BT >
typename BT::template AccessAt< I >::T::Head get( BT &bt )
{
typename BT::template AccessAt< I >::T::Head t;
t.fromReference( bt );
t.shift( BT::template offset< I >() );
return t;
}
}
}
namespace brick_test {
namespace bitlevel {
using namespace ::brick::bitlevel;
struct BitTupleTest {
using U10 = BitField< unsigned, 10 >;
using T10_10 = BitTuple< U10, U10 >;
int bitcount( uint32_t word ) {
int i = 0;
while ( word ) {
if ( word & 1 )
++i;
word >>= 1;
}
return i;
}
TEST(mask) {
/* only works on little endian machines ... */
ASSERT_EQ( 0xFF00u, bitlevel::mask( 8, 8 ) );
ASSERT_EQ( 0xF000u, bitlevel::mask( 12, 4 ) );
ASSERT_EQ( 0x0F00u, bitlevel::mask( 8, 4 ) );
ASSERT_EQ( 60u, bitlevel::mask( 2, 4 ) );// 0b111100
ASSERT_EQ( 28u, bitlevel::mask( 2, 3 ) );// 0b11100
}
TEST(bitcopy) {
uint32_t a = 42, b = 11;
bitlevel::bitcopy( BitPointer( &a ), BitPointer( &b ), 32 );
ASSERT_EQ( a, b );
a = 0xFF00;
bitlevel::bitcopy( BitPointer( &a ), BitPointer( &b, 8 ), 24 );
ASSERT_EQ( b, 0xFF0000u | 42u );
a = 0;
bitlevel::bitcopy( BitPointer( &b, 8 ), BitPointer( &a ), 24 );
ASSERT_EQ( a, 0xFF00u );
bitlevel::bitcopy( BitPointer( &a, 8 ), BitPointer( &b, 8 ), 8 );
a = 0x3FF;
b = 0;
bitlevel::bitcopy( BitPointer( &a, 0 ), BitPointer( &b, 0 ), 10 );
ASSERT_EQ( b, 0x3FFu );
unsigned char from[32], to[32];
std::memset( from, 0, 32 );
std::memset( to, 0, 32 );
from[0] = 1 << 7;
bitlevel::bitcopy( BitPointer( from, 7 ), BitPointer( to, 7 ), 1 );
ASSERT_EQ( int( to[0] ), int( from[ 0 ] ) );
from[0] = 1;
to[0] = 0;
bitlevel::bitcopy( BitPointer( from, 0 ), BitPointer( to, 7 ), 1 );
ASSERT_EQ( int( to[0] ), 1 << 7 );
from[0] = 13;
from[1] = 63;
bitlevel::bitcopy( BitPointer( from, 0 ), BitPointer( to, 32 ), 16 );
ASSERT_EQ( int( to[4] ), int( from[0] ) );
ASSERT_EQ( int( to[5] ), int( from[1] ) );
from[0] = 2;
from[1] = 2;
std::memset( to, 0, 32 );
bitlevel::bitcopy( BitPointer( from, 1 ), BitPointer( to, 32 ), 16 );
ASSERT_EQ( int( to[4] ), 1 );
ASSERT_EQ( int( to[5] ), 1 );
from[0] = 1;
from[1] = 1;
std::memset( to, 0, 32 );
bitlevel::bitcopy( BitPointer( from, 0 ), BitPointer( to, 33 ), 16 );
ASSERT_EQ( int( to[4] ), 2 );
ASSERT_EQ( int( to[5] ), 2 );
from[0] = 1;
from[1] = 1;
std::memset( to, 0, 32 );
for ( int i = 0; i < 16; ++i )
bitlevel::bitcopy( BitPointer( from, i ), BitPointer( to, 33 + i ), 1 );
ASSERT_EQ( int( to[4] ), 2 );
ASSERT_EQ( int( to[5] ), 2 );
for ( int i = 0; i < 16; ++i )
from[i] = 2;
std::memset( to, 0, 32 );
bitlevel::bitcopy( BitPointer( from, 1 ), BitPointer( to, 3 ), 128 );
for ( int i = 0; i < 16; ++i )
ASSERT_EQ( int( to[i] ), 8 );
}
TEST(field) {
int a = 42, b = 0;
typedef BitField< int, 10 > F;
F::Virtual f;
f.fromReference( BitPointer( &b ) );
f.set( a );
ASSERT_EQ( a, 42 );
ASSERT_EQ( a, f );
}
TEST(basic) {
T10_10 x;
ASSERT_EQ( T10_10::bitwidth, 20 );
ASSERT_EQ( T10_10::offset< 0 >(), 0 );
ASSERT_EQ( T10_10::offset< 1 >(), 10 );
auto a = get< 0 >( x );
auto b = get< 1 >( x );
a.set( 5 );
b.set( 7 );
ASSERT_EQ( a, 5u );
ASSERT_EQ( b, 7u );
}
TEST(big) {
bitlevel::BitTuple< BitField< uint64_t, 63 >, BitField< uint64_t, 63 > > x;
ASSERT_EQ( x.bitwidth, 126 );
ASSERT_EQ( x.offset< 0 >(), 0 );
ASSERT_EQ( x.offset< 1 >(), 63 );
get< 0 >( x ).set( (1ull << 62) + 7 );
ASSERT_EQ( get< 0 >( x ), (1ull << 62) + 7 );
ASSERT_EQ( get< 1 >( x ), 0u );
get< 0 >( x ).set( 0 );
get< 1 >( x ).set( (1ull << 62) + 7 );
ASSERT_EQ( get< 0 >( x ), 0u );
ASSERT_EQ( get< 1 >( x ), (1ull << 62) + 7 );
get< 0 >( x ).set( (1ull << 62) + 11 );
ASSERT_EQ( get< 0 >( x ), (1ull << 62) + 11 );
ASSERT_EQ( get< 1 >( x ), (1ull << 62) + 7 );
}
TEST(structure) {
bitlevel::BitTuple< BitField< std::pair< uint64_t, uint64_t >, 120 >, BitField< uint64_t, 63 > > x;
auto v = std::make_pair( (uint64_t( 1 ) << 62) + 7, uint64_t( 33 ) );
ASSERT_EQ( x.bitwidth, 183 );
ASSERT_EQ( x.offset< 0 >(), 0 );
ASSERT_EQ( x.offset< 1 >(), 120 );
get< 1 >( x ).set( 333 );
ASSERT_EQ( get< 1 >( x ), 333u );
get< 0 >( x ).set( v );
ASSERT_EQ( get< 1 >( x ), 333u );
ASSERT( get< 0 >( x ).get() == v );
}
TEST(nested) {
typedef bitlevel::BitTuple< T10_10, T10_10, BitField< unsigned, 3 > > X;
X x;
ASSERT_EQ( X::bitwidth, 43 );
ASSERT_EQ( X::offset< 0 >(), 0 );
ASSERT_EQ( X::offset< 1 >(), 20 );
ASSERT_EQ( X::offset< 2 >(), 40 );
auto a = get< 0 >( x );
auto b = get< 1 >( x );
get< 0 >( a ).set( 5 );
get< 1 >( a ).set( 7 );
get< 0 >( b ).set( 13 );
get< 1 >( b ).set( 533 );
get< 2 >( x ).set( 15 ); /* we expect to lose the MSB */
ASSERT_EQ( get< 0 >( a ), 5u );
ASSERT_EQ( get< 1 >( a ), 7u );
ASSERT_EQ( get< 0 >( b ), 13u );
ASSERT_EQ( get< 1 >( b ), 533u );
ASSERT_EQ( get< 2 >( x ), 7u );
}
TEST(locked) {
bitlevel::BitTuple<
BitField< int, 15 >,
BitLock,
BitField< int, 16 >
> bt;
get< 1 >( bt ).lock();
ASSERT_EQ( get< 0 >( bt ), 0 );
ASSERT_EQ( get< 2 >( bt ), 0 );
ASSERT( get< 1 >( bt ).locked() );
ASSERT( get< 0 >( bt ).word() );
get< 0 >( bt ) = 1;
get< 2 >( bt ) = 1;
ASSERT_EQ( get< 0 >( bt ), 1 );
ASSERT_EQ( get< 2 >( bt ), 1 );
ASSERT_EQ( bitcount( get< 0 >( bt ).word() ), 3 );
get< 1 >( bt ).unlock();
ASSERT_EQ( get< 0 >( bt ), 1 );
ASSERT_EQ( get< 2 >( bt ), 1 );
ASSERT( !get< 1 >( bt ).locked() );
ASSERT_EQ( bitcount( get< 0 >( bt ).word() ), 2 );
get< 0 >( bt ) = 0;
get< 2 >( bt ) = 0;
ASSERT( !get< 0 >( bt ).word() );
}
TEST(assign) {
bitlevel::BitTuple<
BitField< bool, 1 >,
BitField< int, 6 >,
BitField< bool, 1 >
> tuple;
get< 0 >( tuple ) = true;
get< 2 >( tuple ) = get< 0 >( tuple );
ASSERT( get< 2 >( tuple ).get() );
}
struct OperatorTester {
int value;
int expected;
OperatorTester &operator++() { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester operator++( int ) { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester &operator--() { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester &operator--( int ) { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester &operator+=( int ) { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester &operator-=( int ) { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester &operator*=( int ) { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester &operator/=( int ) { ASSERT_UNREACHABLE( "fell through" ); return *this; }
OperatorTester &operator%=( int ) { ASSERT_UNREACHABLE( "fell through" ); return *this; }
void test() { ASSERT_EQ( value, expected ); }
void set( int v, int e ) { value = v; expected = e; }
};
struct TPrI : OperatorTester {
TPrI &operator++() { ++value; return *this; }
};
struct TPoI : OperatorTester {
TPoI operator++( int ) { auto r = *this; value++; return r; }
};
struct TPrD : OperatorTester {
TPrD &operator--() { --value; return *this; }
};
struct TPoD : OperatorTester {
TPoD operator--( int ) { auto r = *this; value--; return r; }
};
struct TPlO : OperatorTester {
TPlO &operator+=( int v ) { value += v; return *this; }
};
struct TMO : OperatorTester {
TMO &operator-=( int v ) { value -= v; return *this; }
};
struct TPoO : OperatorTester {
TPoO &operator*=( int v ) { value *= v; return *this; }
};
struct TSO : OperatorTester {
TSO &operator/=( int v ) { value /= v; return *this; }
};
struct TPrO : OperatorTester {
TPrO &operator%=( int v ) { value %= v; return *this; }
};
template< int N, typename BT, typename L >
void checkOperator( BT &bt, int v, int e, L l ) {
auto t = get< N >( bt ).get();
t.set( v, e );
get< N >( bt ) = t;
l( get< N >( bt ) );
get< N >( bt ).get().test();
}
#define CHECK( N, bt, v, e, test ) checkOperator< N >( bt, v, e, []( decltype( get< N >( bt ) ) item ) { test; } )
TEST(operators) {
bitlevel::BitTuple<
BitField< bool, 4 >,
BitField< TPrI >,// ++v
BitField< TPoI >,// v++
BitField< TPrD >,// --v
BitField< TPoD >,// v--
BitField< TPlO >,// v+=
BitField< TMO >,// v-=
BitField< TPoO >,// v*=
BitField< TSO >,// v/=
BitField< TPrO >,// v%=
BitField< bool, 4 >
> bt;
CHECK( 1, bt, 0, 1, ++item );
CHECK( 2, bt, 0, 1, item++ );
CHECK( 3, bt, 0, -1, --item );
CHECK( 4, bt, 0, -1, item-- );
CHECK( 5, bt, 0, 5, item += 5 );
CHECK( 6, bt, 0, -5, item -= 5 );
CHECK( 7, bt, 2, 14, item *= 7 );
CHECK( 8, bt, 42, 6, item /= 7 );
CHECK( 9, bt, 42, 9, item %= 11 );
}
#undef CHECK
};
}
}
#endif
// vim: syntax=cpp tabstop=4 shiftwidth=4 expandtab
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