a928a438b8
Used cppclean to help identify useless includes and removed them. This involved erroneously included headers, but also cases where forward declarations could have been used rather than a full include.
215 lines
5.7 KiB
C++
215 lines
5.7 KiB
C++
/*
|
|
* Copyright (c) 2003-2005 The Regents of The University of Michigan
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are
|
|
* met: redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer;
|
|
* 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;
|
|
* neither the name of the copyright holders nor the names of its
|
|
* contributors may be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* 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
|
|
* OWNER 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.
|
|
*
|
|
* Authors: Steve Reinhardt
|
|
* Nathan Binkert
|
|
*/
|
|
|
|
#ifndef __BASE_BITFIELD_HH__
|
|
#define __BASE_BITFIELD_HH__
|
|
|
|
#include <inttypes.h>
|
|
|
|
/**
|
|
* Generate a 64-bit mask of 'nbits' 1s, right justified.
|
|
*/
|
|
inline uint64_t
|
|
mask(int nbits)
|
|
{
|
|
return (nbits == 64) ? (uint64_t)-1LL : (1ULL << nbits) - 1;
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
* Extract the bitfield from position 'first' to 'last' (inclusive)
|
|
* from 'val' and right justify it. MSB is numbered 63, LSB is 0.
|
|
*/
|
|
template <class T>
|
|
inline
|
|
T
|
|
bits(T val, int first, int last)
|
|
{
|
|
int nbits = first - last + 1;
|
|
return (val >> last) & mask(nbits);
|
|
}
|
|
|
|
/**
|
|
* Extract the bit from this position from 'val' and right justify it.
|
|
*/
|
|
template <class T>
|
|
inline
|
|
T
|
|
bits(T val, int bit)
|
|
{
|
|
return bits(val, bit, bit);
|
|
}
|
|
|
|
/**
|
|
* Mask off the given bits in place like bits() but without shifting.
|
|
* msb = 63, lsb = 0
|
|
*/
|
|
template <class T>
|
|
inline
|
|
T
|
|
mbits(T val, int first, int last)
|
|
{
|
|
return val & (mask(first+1) & ~mask(last));
|
|
}
|
|
|
|
inline uint64_t
|
|
mask(int first, int last)
|
|
{
|
|
return mbits((uint64_t)-1LL, first, last);
|
|
}
|
|
|
|
/**
|
|
* Sign-extend an N-bit value to 64 bits.
|
|
*/
|
|
template <int N>
|
|
inline
|
|
uint64_t
|
|
sext(uint64_t val)
|
|
{
|
|
int sign_bit = bits(val, N-1, N-1);
|
|
return sign_bit ? (val | ~mask(N)) : val;
|
|
}
|
|
|
|
/**
|
|
* Return val with bits first to last set to bit_val
|
|
*/
|
|
template <class T, class B>
|
|
inline
|
|
T
|
|
insertBits(T val, int first, int last, B bit_val)
|
|
{
|
|
T t_bit_val = bit_val;
|
|
T bmask = mask(first - last + 1) << last;
|
|
return ((t_bit_val << last) & bmask) | (val & ~bmask);
|
|
}
|
|
|
|
/**
|
|
* Overloaded for access to only one bit in value
|
|
*/
|
|
template <class T, class B>
|
|
inline
|
|
T
|
|
insertBits(T val, int bit, B bit_val)
|
|
{
|
|
return insertBits(val, bit, bit, bit_val);
|
|
}
|
|
|
|
/**
|
|
* A convenience function to replace bits first to last of val with bit_val
|
|
* in place.
|
|
*/
|
|
template <class T, class B>
|
|
inline
|
|
void
|
|
replaceBits(T& val, int first, int last, B bit_val)
|
|
{
|
|
val = insertBits(val, first, last, bit_val);
|
|
}
|
|
|
|
/** Overloaded function to allow to access only 1 bit*/
|
|
template <class T, class B>
|
|
inline
|
|
void
|
|
replaceBits(T& val, int bit, B bit_val)
|
|
{
|
|
val = insertBits(val, bit, bit, bit_val);
|
|
}
|
|
/**
|
|
* Returns the bit position of the MSB that is set in the input
|
|
*/
|
|
inline
|
|
int
|
|
findMsbSet(uint64_t val) {
|
|
int msb = 0;
|
|
if (!val)
|
|
return 0;
|
|
if (bits(val, 63,32)) { msb += 32; val >>= 32; }
|
|
if (bits(val, 31,16)) { msb += 16; val >>= 16; }
|
|
if (bits(val, 15,8)) { msb += 8; val >>= 8; }
|
|
if (bits(val, 7,4)) { msb += 4; val >>= 4; }
|
|
if (bits(val, 3,2)) { msb += 2; val >>= 2; }
|
|
if (bits(val, 1,1)) { msb += 1; }
|
|
return msb;
|
|
}
|
|
|
|
/**
|
|
* Returns the bit position of the LSB that is set in the input
|
|
*/
|
|
inline int
|
|
findLsbSet(uint64_t val) {
|
|
int lsb = 0;
|
|
if (!val)
|
|
return sizeof(val) * 8;
|
|
if (!bits(val, 31,0)) { lsb += 32; val >>= 32; }
|
|
if (!bits(val, 15,0)) { lsb += 16; val >>= 16; }
|
|
if (!bits(val, 7,0)) { lsb += 8; val >>= 8; }
|
|
if (!bits(val, 3,0)) { lsb += 4; val >>= 4; }
|
|
if (!bits(val, 1,0)) { lsb += 2; val >>= 2; }
|
|
if (!bits(val, 0,0)) { lsb += 1; }
|
|
return lsb;
|
|
}
|
|
|
|
/**
|
|
* Checks if a number is a power of two, or zero.
|
|
*/
|
|
template <class T>
|
|
inline bool
|
|
isPow2(T v) {
|
|
return (v & (v - 1)) == (T)0;
|
|
}
|
|
|
|
/**
|
|
* Returns the number of set ones in the provided value.
|
|
* PD algorithm from
|
|
* http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel
|
|
*/
|
|
inline int
|
|
popCount(uint64_t val) {
|
|
#ifndef __has_builtin
|
|
#define __has_builtin(foo) 0
|
|
#endif
|
|
#if defined(__GNUC__) || (defined(__clang__) && __has_builtin(__builtin_popcountl))
|
|
return __builtin_popcountl(val);
|
|
#else
|
|
const uint64_t m1 = 0x5555555555555555; // ..010101b
|
|
const uint64_t m2 = 0x3333333333333333; // ..110011b
|
|
const uint64_t m4 = 0x0f0f0f0f0f0f0f0f; // ..001111b
|
|
const uint64_t sum = 0x0101010101010101;
|
|
|
|
val -= (val >> 1) & m1; // 2 bits count -> 2 bits
|
|
val = (val & m2) + ((val >> 2) & m2); // 4 bits count -> 4 bits
|
|
val = (val + (val >> 4)) & m4; // 8 bits count -> 8 bits
|
|
return (val * sum) >> 56; // horizontal sum
|
|
#endif // defined(__GNUC__) || (defined(__clang__) && __has_builtin(__builtin_popcountl))
|
|
}
|
|
#endif // __BASE_BITFIELD_HH__
|