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debug: add func desc in debug.h

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Bruno Raoult
2024-01-03 19:06:52 +01:00
parent 7bba3c559b
commit a41ca50404
5 changed files with 57 additions and 21 deletions
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include/bitops.h Normal file
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/* bits.h - bits functions.
*
* Copyright (C) 2021-2022 Bruno Raoult ("br")
* Licensed under the GNU General Public License v3.0 or later.
* Some rights reserved. See COPYING.
*
* You should have received a copy of the GNU General Public License along with this
* program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
*
* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
*
*/
#ifndef _BITS_H
#define _BITS_H
#include "br.h"
/**
* print_bitops_impl() - print bitops implementation.
*
* For basic bitops (popcount, ctz, etc...), print the implementation
* (builtin, emulated, ...).
*/
void print_bitops_impl(void);
#ifndef __has_builtin
#define __has_builtin(x) 0
#endif
/* no plan to support 32bits for now...
* #if __WORDSIZE != 64
* #error "Only 64 bits word size supported."
* #endif
*/
/* lsb, msb: least/most significant bit: 10101000
* msb = 7 ^ ^ lsb = 3
*/
#define lsb64(x) (ctz64(x))
#define lsb32(x) (ctz32(x))
#define msb64(x) (63 ^ clz64(x))
#define msb32(x) (31 ^ clz32(x))
/* count set bits: 10101000 -> 3
* ^ ^ ^
*/
static __always_inline int popcount64(u64 n)
{
# if __has_builtin(__builtin_popcountll)
return __builtin_popcountll(n);
# else
int count = 0;
while (n) {
count++;
n &= (n - 1);
}
return count;
# endif
}
static __always_inline int popcount32(u32 n)
{
# if __has_builtin(__builtin_popcount)
return __builtin_popcount(n);
# else
int count = 0;
while (n) {
count++;
n &= (n - 1);
}
return count;
# endif
}
/* count trailing zeroes : 00101000 -> 3
* ^^^
*/
static __always_inline int ctz64(u64 n)
{
# if __has_builtin(__builtin_ctzll)
return __builtin_ctzll(n);
# elif __has_builtin(__builtin_clzll)
return __WORDSIZE - (__builtin_clzll(n & -n) + 1);
# else
return popcount64((n & -n) - 1);
# endif
}
static __always_inline int ctz32(u32 n)
{
# if __has_builtin(__builtin_ctz)
return __builtin_ctz(n);
# elif __has_builtin(__builtin_clz)
return __WORDSIZE - (__builtin_clz(n & -n) + 1);
# else
return popcount32((n & -n) - 1);
# endif
}
/* clz - count leading zeroes : 00101000 -> 2
* ^^
*/
static __always_inline int clz64(u64 n)
{
# if __has_builtin(__builtin_clzll)
return __builtin_clzll(n);
# else
u64 r, q;
r = (n > 0xFFFFFFFF) << 5; n >>= r;
q = (n > 0xFFFF) << 4; n >>= q; r |= q;
q = (n > 0xFF ) << 3; n >>= q; r |= q;
q = (n > 0xF ) << 2; n >>= q; r |= q;
q = (n > 0x3 ) << 1; n >>= q; r |= q;
r |= (n >> 1);
return 64 - r - 1;
# endif
}
static __always_inline int clz32(u32 n)
{
# if __has_builtin(__builtin_clz)
return __builtin_clz(n);
# else
u32 r, q;
r = (n > 0xFFFF) << 4; n >>= r;
q = (n > 0xFF ) << 3; n >>= q; r |= q;
q = (n > 0xF ) << 2; n >>= q; r |= q;
q = (n > 0x3 ) << 1; n >>= q; r |= q;
r |= (n >> 1);
return 32 - r - 1;
# endif
}
/* fls - return one plus msb : 00101000 -> 6
* ^
*/
static __always_inline int fls64(u64 n)
{
if (!n)
return 0;
return 64 - clz64(n);
}
static __always_inline int fls32(u32 n)
{
if (!n)
return 0;
return 32 - clz32(n);
}
/* ffs - return one plus lsb index: 00101000 -> 4
* ^
*/
static __always_inline uint ffs64(u64 n)
{
# if __has_builtin(__builtin_ffsll)
return __builtin_ffsll(n);
# elif __has_builtin(__builtin_ctzll)
if (n == 0)
return (0);
return __builtin_ctzll(n) + 1;
# else
return popcount64(n ^ ~-n);
# endif
}
static __always_inline uint ffs32(u32 n)
{
# if __has_builtin(__builtin_ffs)
return __builtin_ffs(n);
# elif __has_builtin(__builtin_ctz)
if (n == 0)
return (0);
return __builtin_ctz(n) + 1;
# else
return popcount32(n ^ ~-n);
# endif
}
/* rolXX/rorXX are taken from kernel's <linux/bitops.h> are are:
* SPDX-License-Identifier: GPL-2.0
*/
/**
* rol64 - rotate a 64-bit value left
* @word: value to rotate
* @shift: bits to roll
*/
static inline u64 rol64(u64 word, unsigned int shift)
{
return (word << (shift & 63)) | (word >> ((-shift) & 63));
}
/**
* ror64 - rotate a 64-bit value right
* @word: value to rotate
* @shift: bits to roll
*/
static inline u64 ror64(u64 word, unsigned int shift)
{
return (word >> (shift & 63)) | (word << ((-shift) & 63));
}
/**
* rol32 - rotate a 32-bit value left
* @word: value to rotate
* @shift: bits to roll
*/
static inline u32 rol32(u32 word, unsigned int shift)
{
return (word << (shift & 31)) | (word >> ((-shift) & 31));
}
/**
* ror32 - rotate a 32-bit value right
* @word: value to rotate
* @shift: bits to roll
*/
static inline u32 ror32(u32 word, unsigned int shift)
{
return (word >> (shift & 31)) | (word << ((-shift) & 31));
}
/**
* rol16 - rotate a 16-bit value left
* @word: value to rotate
* @shift: bits to roll
*/
static inline u16 rol16(u16 word, unsigned int shift)
{
return (word << (shift & 15)) | (word >> ((-shift) & 15));
}
/**
* ror16 - rotate a 16-bit value right
* @word: value to rotate
* @shift: bits to roll
*/
static inline u16 ror16(u16 word, unsigned int shift)
{
return (word >> (shift & 15)) | (word << ((-shift) & 15));
}
/**
* rol8 - rotate an 8-bit value left
* @word: value to rotate
* @shift: bits to roll
*/
static inline u8 rol8(u8 word, unsigned int shift)
{
return (word << (shift & 7)) | (word >> ((-shift) & 7));
}
/**
* ror8 - rotate an 8-bit value right
* @word: value to rotate
* @shift: bits to roll
*/
static inline u8 ror8(u8 word, unsigned int shift)
{
return (word >> (shift & 7)) | (word << ((-shift) & 7));
}
/**
* __ilog2 - non-constant log of base 2 calculators
* - the arch may override these in asm/bitops.h if they can be implemented
* more efficiently than using fls() and fls64()
* - the arch is not required to handle n==0 if implementing the fallback
*/
static __always_inline __attribute__((const))
int __ilog2_u64(u64 n)
{
return fls64(n) - 1;
}
static __always_inline __attribute__((const))
int __ilog2_u32(u32 n)
{
return fls32(n) - 1;
}
/**
* is_power_of_2() - check if a value is a power of two
* @n: the value to check
*
* Determine whether some value is a power of two, where zero is
* *not* considered a power of two.
* Return: true if @n is a power of 2, otherwise false.
*/
static inline __attribute__((const))
bool is_power_of_2(unsigned long n)
{
return (n != 0 && ((n & (n - 1)) == 0));
}
/**
* __roundup_pow_of_two() - round up to nearest power of two
* @n: value to round up
*/
static inline __attribute__((const))
u64 __roundup_pow_of_two(u64 n)
{
return 1UL << fls64(n - 1);
}
/**
* __rounddown_pow_of_two() - round down to nearest power of two
* @n: value to round down
*/
static inline __attribute__((const)) u64 __rounddown_pow_of_two(u64 n)
{
return 1UL << (fls64(n) - 1);
}
/**
* ilog2 - log base 2 of 32-bit or a 64-bit unsigned value
* @n: parameter
*
* constant-capable log of base 2 calculation
* - this can be used to initialise global variables from constant data, hence
* the massive ternary operator construction
*
* selects the appropriately-sized optimised version depending on sizeof(n)
*/
#define ilog2(n) \
( \
__builtin_constant_p(n) ? \
((n) < 2 ? 0 : \
63 - __builtin_clzll(n)) : \
(sizeof(n) <= 4) ? \
__ilog2_u32(n) : \
__ilog2_u64(n) \
)
/**
* roundup_pow_of_two - round the given value up to nearest power of two
* @n: parameter
*
* round the given value up to the nearest power of two
* - the result is undefined when n == 0
* - this can be used to initialise global variables from constant data
*/
#define roundup_pow_of_two(n) \
( \
__builtin_constant_p(n) ? ( \
((n) == 1) ? 1 : \
(1UL << (ilog2((n) - 1) + 1)) \
) : \
__roundup_pow_of_two(n) \
)
/**
* rounddown_pow_of_two - round the given value down to nearest power of two
* @n: parameter
*
* round the given value down to the nearest power of two
* - the result is undefined when n == 0
* - this can be used to initialise global variables from constant data
*/
#define rounddown_pow_of_two(n) \
( \
__builtin_constant_p(n) ? ( \
(1UL << ilog2(n))) : \
__rounddown_pow_of_two(n) \
)
static inline __attribute_const__ int __order_base_2(unsigned long n)
{
return n > 1 ? ilog2(n - 1) + 1 : 0;
}
/**
* order_base_2 - calculate the (rounded up) base 2 order of the argument
* @n: parameter
*
* The first few values calculated by this routine:
* ob2(0) = 0
* ob2(1) = 0
* ob2(2) = 1
* ob2(3) = 2
* ob2(4) = 2
* ob2(5) = 3
* ... and so on.
*/
#define order_base_2(n) \
( \
__builtin_constant_p(n) ? ( \
((n) == 0 || (n) == 1) ? \
0 : \
ilog2((n) - 1) + 1) : \
__order_base_2(n) \
)
static inline __attribute__((const)) int __bits_per(unsigned long n)
{
if (n < 2)
return 1;
if (is_power_of_2(n))
return order_base_2(n) + 1;
return order_base_2(n);
}
/**
* bits_per - calculate the number of bits required for the argument
* @n: parameter
*
* This is constant-capable and can be used for compile time
* initializations, e.g bitfields.
*
* The first few values calculated by this routine:
* bf(0) = 1
* bf(1) = 1
* bf(2) = 2
* bf(3) = 2
* bf(4) = 3
* ... and so on.
*/
#define bits_per(n) \
( \
__builtin_constant_p(n) ? ( \
((n) == 0 || (n) == 1) ? \
1 : \
ilog2(n) + 1 : \
__bits_per(n) \
)
/**
* bit_for_each - iterate over an u64/u32 bits
* @pos: an int used as current bit
* @tmp: a temp u64/u32 used as temporary storage
* @ul: the u64/u32 to loop over
*
* Usage:
* u64 u=139, _t; // u=b10001011
* int cur;
* bit_for_each64(cur, _t, u) {
* printf("%d\n", cur);
* }
* This will display the position of each bit set in ul: 1, 2, 4, 8
*
* I should probably re-think the implementation...
*/
#define bit_for_each64(pos, tmp, ul) \
for (tmp = ul, pos = ctz64(tmp); tmp; tmp ^= 1UL << pos, pos = ctz64(tmp))
#define bit_for_each32(pos, tmp, ul) \
for (tmp = ul, pos = ctz32(tmp); tmp; tmp ^= 1U << pos, pos = ctz32(tmp))
/** or would it be more useful (counting bits from zero instead of 1) ?
*/
#define bit_for_each64_1(pos, tmp, ul) \
for (tmp = ul, pos = ffs64(tmp); tmp; tmp &= (tmp - 1), pos = ffs64(tmp))
#define bit_for_each32_1(pos, tmp, ul) \
for (tmp = ul, pos = ffs32(tmp); tmp; tmp &= (tmp - 1), pos = ffs32(tmp))
#endif /* _BITS_H */