697bca74-2893-4324-97a5-dd0e956ca48b

Committed 23 Dec 2025 12:19PM UTC coverage: 66.747% (-0.3%) from 67.014%

Build # 697bca74-2893-4324-97a5-dd0e956ca48b

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circleci

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Nic30

Commit Message

feat(bit_utils): separate_least_significant_1, ctlo, ctto

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45.47

/pyMathBitPrecise/bit_utils.py

#!/usr/bin/env python3
# -*- coding: UTF-8 -*-
import math
from typing import List, Tuple, Generator, Union, Optional, Literal, Sequence

from pyMathBitPrecise.utils import grouper


def mask(bits: int) -> int:
    """
    Generate mask of specified size (sequence of '1')
    """
    return (1 << bits) - 1


def bit_field(_from: int, to: int) -> int:
    """
    Generate int which has bits '_from' to 'to' set to '1'

    :note: _from 0 to 1 -> '1'
    """
    w = to - _from
    return mask(w) << _from


def get_bit(val: int, bitNo: int) -> int:
    """
    Get bit from int
    """
    return (val >> bitNo) & 1


def get_bit_range(val: int, bitsStart: int, bitsLen: int) -> int:
    """
    Get sequence of bits from an int value
    """
    val >>= bitsStart
    return val & mask(bitsLen)


def get_single_1_at_position_of_least_significant_0(x: int):
    """
    Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
    
    10100111 -> 00001000
    """
    assert x >= 0, x
    return ~x & (x + 1)


def get_single_0_at_position_of_least_significant_1(x: int, width: int):
    """
    Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
    
    10101000 -> 11110111
    """
    assert x >= 0, x
    res = ~x | (x - 1)
    return to_unsigned(res, width)


def clean_bit(val: int, bitNo: int) -> int:
    """
    Set a specified bit to '0'
    """
    return val & ~(1 << bitNo)


def clear_least_significant_1(x: int) -> int:
    """
    Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
    010110 -> 010100
    
    :note: can be used for 2**n test
    """
    # :note: this is equivalent to x - (x & -x)
    return x & (x - 1)


def clear_trailing_1s(x: int) -> int:
    """
    Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
    10100111 -> 10100000
    
    :note: can be used for 2**n – 1 test
    """
    return x & (x + 1)


def set_bit(val: int, bitNo: int) -> int:
    """
    Set a specified bit to '1'
    """
    return val | (1 << bitNo)


def set_least_significant_0(x: int) -> int:
    """
    Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits

    101001 -> 101011
    """
    return x | (x + 1)


def set_trailing_0s(x: int) -> int:
    """
    Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits

    10101000 -> 10101111
    """
    return x | (x - 1)


def separate_least_significant_1(x: int):
    """
    1100 -> 0100
    """
    return x & -x


def toggle_bit(val: int, bitNo: int) -> int:
    """
    Toggle specified bit in int
    """
    return val ^ (1 << bitNo)


def set_bit_range(val: int, bitStart: int, bitsLen: int, newBits: int) -> int:
    """
    Set specified range of bits in int to a specified value
    """
    _mask = mask(bitsLen)
    newBits &= _mask

    _mask <<= bitStart
    newBits <<= bitStart

    return (val & ~_mask) | newBits


def bit_set_to(val: int, bitNo: int, bitVal: int) -> int:
    """
    Set specified bit in int to a specified value
    """
    if bitVal == 0:
        return clean_bit(val, bitNo)
    elif bitVal == 1:
        return set_bit(val, bitNo)
    else:
        raise ValueError(("Invalid value of bit to set", bitVal))


def byte_mask_to_bit_mask_int(m: int, width: int, byte_width:int=8) -> int:
    """
    Expands each bit byte_width times to convert from byte mask to bit mask
    """
    res = 0
    mTmp = m
    byte_mask = mask(byte_width)
    for i in range(width):
        b = mTmp & 1
        if b:
            res |= byte_mask << (i * byte_width)
        mTmp >>= 1

    return res


def byte_mask_to_bit_mask(m: "Bits3Val", byte_width:int=8) -> "Bits3Val":
    """
    Replicate each bit byte_width times
    """
    res = None
    for b in m:
        if res is None:
            res = b._sext(byte_width)
        else:
            res = b._sext(byte_width)._concat(res)

    return res


def bit_mask_to_byte_mask_int(m: int, width: int, byte_width:int=8) -> int:
    """
    Compresses all bit in byte to 1 bit to convert from bit mask to byte mask
    """
    assert width % byte_width == 0
    mTmp = m
    res = 0
    byte_mask = mask(byte_width)
    for i in range(width // byte_width):
        B = mTmp & byte_mask
        if B == byte_mask:
            res |= 1 << i
        else:
            assert B == 0, "Each byte must be entirely set or entirely unset"
        mTmp >>= byte_width

    return res


def apply_set_and_clear(val: int, set_flag: int, clear_flag: int):
    """
    :param val: an input value of the flag(s)
    :param set_flag: a mask of bits to set to 1
    :param clear_flag: a mask of bits to set to 0
    :note: set has higher priority

    :return: new value of the flag
    """
    return (val & ~clear_flag) | set_flag


def apply_write_with_mask(current_data: "Bits3val", new_data: "Bits3val", write_mask: "Bits3val") -> "Bits3val":
    """
    :return: an updated value current_data which has bytes defined by write_mask updated from new_data
    """
    m = byte_mask_to_bit_mask(write_mask)
    return apply_set_and_clear(current_data, new_data & m, m)


def extend_to_width_multiple_of_8(v: "Bits3val") -> "Bits3val":
    """
    make width of signal modulo 8 equal to 0
    """
    w = v._dtype.bit_length()
    cosest_multiple_of_8 = math.ceil((w // 8) / 8) * 8
    if cosest_multiple_of_8 == w:
        return v
    else:
        return v._ext(cosest_multiple_of_8)


def align(val: int, lowerBitCntToAlign: int) -> int:
    """
    Cut off lower bits to align a int value.
    """
    val = val >> lowerBitCntToAlign
    return val << lowerBitCntToAlign


def align_with_known_width(val, width: int, lowerBitCntToAlign: int):
    """
    Does same as :func:`~.align` just with the known width of val
    """
    return val & (mask(width - lowerBitCntToAlign) << lowerBitCntToAlign)


def iter_bits(val: int, length: int) -> Generator[Literal[0, 1], None, None]:
    """
    Iterate bits in int. LSB first.
    """
    for _ in range(length):
        yield val & 1
        val >>= 1


def iter_bits_sequences(val: int, length: int) -> Generator[Tuple[Literal[0, 1], int], None, None]:
    """
    Iter tuples (bitVal, number of same bits), lsb first
    """
    assert length > 0, length
    assert val >= 0
    # start of new bit seqence
    w = 1
    valBit = val & 1
    val >>= 1
    foundBit = valBit
    for _ in range(length - 1):
        # extract single bit from val
        valBit = val & 1
        val >>= 1
        # check if it fits into current bit sequence
        if valBit == foundBit:
            w += 1
        else:
            # end of sequence of same bits
            yield (foundBit, w)
            foundBit = valBit
            w = 1

    if w != 0:
        yield (foundBit, w)


def to_signed(val: int, width: int) -> int:
    """
    Convert unsigned int to negative int which has same bits set (emulate sign overflow).

    :note: bits in value are not changed, just python int object
        has signed flag set properly. And number is in expected range.
    """
    if val > 0:
        msb = 1 << (width - 1)
        if val & msb:
            val -= mask(width) + 1
    return val


def to_unsigned(val, width) -> int:
    if val < 0:
        return val & mask(width)
    else:
        return val


def mask_bytes(val: int, byte_mask: int, mask_bit_length: int) -> int:
    """
    Use each bit in byte_mask as a mask for each byte in val.

    :note: Useful for masking of value for HW interfaces where mask
        is represented by a vector of bits where each bit is mask
        for byte in data vector.
    """
    res = 0
    for i, m in enumerate(iter_bits(byte_mask, mask_bit_length)):
        if m:
            res |= (val & 0xff) << (i * 8)
        val >>= 8
    return res


INT_BASES = {
    "b": 2,
    "o": 8,
    "d": 10,
    "h": 16,
}


class ValidityError(ValueError):
    """
    Value is not fully defined and thus can not be used
    """


def normalize_slice(s: slice, obj_width: int) -> Tuple[int, int]:
    start, stop, step = s.start, s.stop, s.step
    if step is not None and step != -1:
        raise NotImplementedError(s.step)
    else:
        step = -1
    if stop is None:
        stop = 0
    else:
        stop = int(stop)

    if start is None:
        start = int(obj_width)
    else:
        start = int(start)
    # n...0
    if start <= stop:
        raise IndexError(s)
    firstBitNo = stop
    size = start - stop
    if start < 0 or stop < 0 or size < 0 or start > obj_width:
        raise IndexError(s)

    return firstBitNo, size


def reverse_bits(val: int, width: int):
    """
    Reverse bits in integer value of specified width
    """
    v = 0
    for i in range(width):
        v |= (get_bit(val, width - i - 1) << i)
    return v


def extend_to_size(collection: Sequence, items: int, pad=0):
    toAdd = items - len(collection)
    assert toAdd >= 0
    for _ in range(toAdd):
        collection.append(pad)

    return collection


def rotate_right(v: int, width: int, shAmount:int):
    # https://www.geeksforgeeks.org/rotate-bits-of-an-integer/
    assert v >= 0, v
    assert width > 0, width
    assert shAmount >= 0, shAmount
    return (v >> shAmount) | ((v << (width - shAmount)) & mask(width))


def rotate_left(v: int, width: int, shAmount:int):
    # https://www.geeksforgeeks.org/rotate-bits-of-an-integer/
    assert v >= 0, v
    assert width > 0, width
    assert shAmount >= 0, shAmount
    return ((v << shAmount) & mask(width)) | (v >> (width - shAmount))


def bit_list_reversed_endianity(bitList: List[Literal[0, 1]], extend=True):
    w = len(bitList)
    i = w

    items: list[Literal[0, 1]] = []
    while i > 0:
        # take last 8 bits or rest
        lower = max(i - 8, 0)
        b = bitList[lower:i]
        if extend:
            extend_to_size(b, 8)
        items.extend(b)
        i -= 8

    return items


def bit_list_reversed_bits_in_bytes(bitList: List[Literal[0, 1]], extend=None):
    "Byte reflection  (0x0f -> 0xf0)"
    w = len(bitList)
    if extend is None:
        assert w % 8 == 0

    tmp: list[Literal[0, 1]] = []
    for db in grouper(8, bitList, padvalue=0):
        tmp.extend(reversed(db))

    if not extend and len(tmp) != w:
        rem = w % 8
        # rm zeros from [0, 0, 0, 0, 0, d[2], d[1], d[0]] like
        tmp = tmp[:w - rem] + tmp[-rem:]

    return tmp


def bytes_to_bit_list_lower_bit_first(bytes_: bytes) -> List[Literal[0, 1]]:
    """
    b'\x01' to [1, 0, 0, 0, 0, 0, 0, 0]
    """
    result: List[Literal[0, 1]] = []
    for byte in bytes_:
        for _ in range(8):
            result.append(byte & 0b1)
            byte >>= 1
    return result


def bytes_to_bit_list_upper_bit_first(bytes_: bytes) -> List[Literal[0, 1]]:
    """
    b'\x01' to [0, 0, 0, 0, 0, 0, 0, 1]
    """
    result: List[Literal[0, 1]] = []
    for byte in bytes_:
        for _ in range(8):
            result.append((byte & 0x80) >> 7)
            byte <<= 1
    return result


def byte_list_to_be_int(_bytes: List[Literal[0, 1, 2, 3, 4, 5, 6, 7]]):
    """
    In input list LSB first, in result little endian ([1, 0] -> 0x0001)
    """
    return int_list_to_int(_bytes, 8)


def bit_list_to_int(bitList: List[Literal[0, 1]]):
    """
    In input list LSB first, in result little endian ([0, 1] -> 0b10)
    """
    res = 0
    for i, r in enumerate(bitList):
        res |= (r & 0x1) << i
    return res


def bit_list_to_bytes(bitList: List[Literal[0, 1]]) -> bytes:
    byteCnt = len(bitList) // 8
    if len(bitList) % 8:
        byteCnt += 1
    return bit_list_to_int(bitList).to_bytes(byteCnt, 'big')


def int_list_to_int(il: List[int], item_width: int):
    """
    [0x0201, 0x0403] -> 0x04030201
    """
    v = 0
    for i, b in enumerate(il):
        v |= b << (i * item_width)

    return v


def int_to_int_list(v: int, item_width: int, number_of_items: int):
    """
    opposite of :func:`~.int_list_to_int`
    """
    item_mask = mask(item_width)
    res = []
    for _ in range(number_of_items):
        res.append(v & item_mask)
        v >>= item_width

    assert v == 0, ("there should be nothing left, the value is larger", v)
    return res


def reverse_byte_order(val: "Bits3val"):
    """
    Reverse byteorder (littleendian/bigendian) of signal or value
    """
    w = val._dtype.bit_length()
    i = w
    items = []

    while i > 0:
        # take last 8 bytes or rest
        lower = max(i - 8, 0)
        items.append(val[i:lower])
        i -= 8

    # Concat(*items)
    top = None
    for s in items:
        if top is None:
            top = s
        else:
            top = top._concat(s)
    return top


def reverse_byte_order_int(val: int, width: int):
    assert width % 8 == 0, width
    return int.from_bytes(val.to_bytes(width // 8, "big"), "little")


def is_power_of_2(v: Union["Bits3val", int]):
    if isinstance(v, int):
        assert v > 0
        return (v != 0) & (clear_least_significant_1(v) == 0)
    else:
        return (v != 0) & (clear_least_significant_1(v)._eq(0))


def next_power_of_2(v: Union["Bits3val", int], width:Optional[int]=None):
    # depend on the fact that v < 2^width
    v = v - 1
    if isinstance(v, int):
        if v < 0:
            assert width is not None
            v = to_unsigned(v, width)
        elif width is None:
            width = v.bit_length() + 1
    else:
        width = v._dtype.bit_length()

    i = 1
    while True:
        v |= (v >> i)  # 1, 2, 4, 8, 16 for 32b
        i <<= 1
        if i > (width // 2):
            break

    v = v + 1

    if isinstance(v, int):
        v &= mask(width)

    return v


def round_up_to_multiple_of(v: int, divider:int):
    """
    Round up the v to be the multiple of divider
    """
    _v = (v // divider) * divider
    if _v < v:
        return _v + divider
    else:
        return _v


def round_up_to_power_of_2(x: int):
    assert x >= 0, x
    if x == 0:
        return 0
    return int(2 ** math.ceil(math.log2(x)))


def ctlz(val: int, width: int) -> int:
    """
    Count leading zeros
    """
    if val == 0:
        return width

    # Bisection method.
    ZeroBits = 0
    if not is_power_of_2(width):
        # because alg. works only for pow2 width
        _w = next_power_of_2(width, 64)
        paddingBits = _w - width
        width = _w
    else:
        paddingBits = 0

    Shift = width >> 1
    while Shift:
        Tmp = val >> Shift
        if Tmp:
            val = Tmp
        else:
            ZeroBits |= Shift
        Shift >>= 1
    return ZeroBits - paddingBits


def ctlo(val: int, width: int) -> int:
    """
    Count leading ones
    """
    return ctlz(~val, width)


def _ctpop_u64(v: int) -> int:
    v = v - ((v >> 1) & 0x5555555555555555)
    v = (v & 0x3333333333333333) + ((v >> 2) & 0x3333333333333333)
    v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0F
    return (v * 0x0101010101010101) >> 56


def ctpop(val: int, width: int):
    """
    count number of 1 in val (population count)
    """
    res = 0
    mask_u64 = mask(64)
    while True:
        res += _ctpop_u64(val & mask_u64)
        width -= 64
        if width <= 0:
            break
        val >>= 64
    return res


def cttz(val: int, width: int):
    """
    Count trailing zeros
    """
    if val == 0:
        return width
    if val & 0x1:
        return 0

    # ctpop method: (x & -x).bit_length() - 1
    # Bisection method.
    ZeroBits = 0
    if not is_power_of_2(width):
        width = next_power_of_2(width, 64)  # because alg. works only for pow2  width
    Shift = width >> 1
    Mask = mask(width) >> Shift
    while Shift:
        if (val & Mask) == 0:
            val >>= Shift
            ZeroBits |= Shift

        Shift >>= 1
        Mask >>= Shift

    return ZeroBits


def ctto(val: int):
    """
    Count trailing ones
    """
    return cttz(~val, val.bit_length())

1	#!/usr/bin/env python3
2	# -- coding: UTF-8 --
3	import math	1✔
4	from typing import List, Tuple, Generator, Union, Optional, Literal, Sequence	1✔
5
6	from pyMathBitPrecise.utils import grouper	1✔
7
8
9	def mask(bits: int) -> int:	1✔
10	"""
11	Generate mask of specified size (sequence of '1')
12	"""
13	return (1 << bits) - 1	1✔
14
15
16	def bit_field(_from: int, to: int) -> int:	1✔
17	"""
18	Generate int which has bits '_from' to 'to' set to '1'
19
20	:note: _from 0 to 1 -> '1'
21	"""
22	w = to - _from	1✔
23	return mask(w) << _from	1✔
24
25
26	def get_bit(val: int, bitNo: int) -> int:	1✔
27	"""
28	Get bit from int
29	"""
30	return (val >> bitNo) & 1	1✔
31
32
33	def get_bit_range(val: int, bitsStart: int, bitsLen: int) -> int:	1✔
34	"""
35	Get sequence of bits from an int value
36	"""
37	val >>= bitsStart	1✔
38	return val & mask(bitsLen)	1✔
39
40
41	def get_single_1_at_position_of_least_significant_0(x: int):	1✔
42	"""
43	Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
44
45	10100111 -> 00001000
46	"""
47	assert x >= 0, x	1✔
48	return ~x & (x + 1)	1✔
49
50
51	def get_single_0_at_position_of_least_significant_1(x: int, width: int):	1✔
52	"""
53	Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
54
55	10101000 -> 11110111
56	"""
57	assert x >= 0, x	1✔
58	res = ~x \| (x - 1)	1✔
59	return to_unsigned(res, width)	1✔
60
61
62	def clean_bit(val: int, bitNo: int) -> int:	1✔
63	"""
64	Set a specified bit to '0'
65	"""
66	return val & ~(1 << bitNo)	1✔
67
68
69	def clear_least_significant_1(x: int) -> int:	1✔
70	"""
71	Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
72	010110 -> 010100
73
74	:note: can be used for 2**n test
75	"""
76	# :note: this is equivalent to x - (x & -x)
77	return x & (x - 1)	1✔
78
79
80	def clear_trailing_1s(x: int) -> int:	1✔
81	"""
82	Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
83	10100111 -> 10100000
84
85	:note: can be used for 2**n – 1 test
86	"""
87	return x & (x + 1)	1✔
88
89
90	def set_bit(val: int, bitNo: int) -> int:	1✔
91	"""
92	Set a specified bit to '1'
93	"""
94	return val \| (1 << bitNo)	1✔
95
96
97	def set_least_significant_0(x: int) -> int:	1✔
98	"""
99	Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
100
101	101001 -> 101011
102	"""
103	return x \| (x + 1)	1✔
104
105
106	def set_trailing_0s(x: int) -> int:	1✔
107	"""
108	Hacker's Delight: 2nd Edition, 2-1 Manipulating Rightmost Bits
109
110	10101000 -> 10101111
111	"""
112	return x \| (x - 1)	1✔
113
114
115	def separate_least_significant_1(x: int):	1✔
116	"""
117	1100 -> 0100
118	"""
NEW 119	return x & -x	×
120
121
122	def toggle_bit(val: int, bitNo: int) -> int:	1✔
123	"""
124	Toggle specified bit in int
125	"""
126	return val ^ (1 << bitNo)	1✔
127
128
129	def set_bit_range(val: int, bitStart: int, bitsLen: int, newBits: int) -> int:	1✔
130	"""
131	Set specified range of bits in int to a specified value
132	"""
133	_mask = mask(bitsLen)	1✔
134	newBits &= _mask	1✔
135
136	_mask <<= bitStart	1✔
137	newBits <<= bitStart	1✔
138
139	return (val & ~_mask) \| newBits	1✔
140
141
142	def bit_set_to(val: int, bitNo: int, bitVal: int) -> int:	1✔
143	"""
144	Set specified bit in int to a specified value
145	"""
146	if bitVal == 0:	1✔
147	return clean_bit(val, bitNo)	1✔
148	elif bitVal == 1:	1!
149	return set_bit(val, bitNo)	1✔
150	else:
151	raise ValueError(("Invalid value of bit to set", bitVal))	×
152
153
154	def byte_mask_to_bit_mask_int(m: int, width: int, byte_width:int=8) -> int:	1✔
155	"""
156	Expands each bit byte_width times to convert from byte mask to bit mask
157	"""
158	res = 0	×
159	mTmp = m	×
160	byte_mask = mask(byte_width)	×
161	for i in range(width):	×
162	b = mTmp & 1	×
163	if b:	×
164	res \|= byte_mask << (i * byte_width)	×
165	mTmp >>= 1	×
166
167	return res	×
168
169
170	def byte_mask_to_bit_mask(m: "Bits3Val", byte_width:int=8) -> "Bits3Val":	1✔
171	"""
172	Replicate each bit byte_width times
173	"""
174	res = None	×
175	for b in m:	×
176	if res is None:	×
177	res = b._sext(byte_width)	×
178	else:
179	res = b._sext(byte_width)._concat(res)	×
180
181	return res	×
182
183
184	def bit_mask_to_byte_mask_int(m: int, width: int, byte_width:int=8) -> int:	1✔
185	"""
186	Compresses all bit in byte to 1 bit to convert from bit mask to byte mask
187	"""
188	assert width % byte_width == 0	×
189	mTmp = m	×
190	res = 0	×
191	byte_mask = mask(byte_width)	×
192	for i in range(width // byte_width):	×
193	B = mTmp & byte_mask	×
194	if B == byte_mask:	×
195	res \|= 1 << i	×
196	else:
197	assert B == 0, "Each byte must be entirely set or entirely unset"	×
198	mTmp >>= byte_width	×
199
200	return res	×
201
202
203	def apply_set_and_clear(val: int, set_flag: int, clear_flag: int):	1✔
204	"""
205	:param val: an input value of the flag(s)
206	:param set_flag: a mask of bits to set to 1
207	:param clear_flag: a mask of bits to set to 0
208	:note: set has higher priority
209
210	:return: new value of the flag
211	"""
212	return (val & ~clear_flag) \| set_flag	1✔
213
214
215	def apply_write_with_mask(current_data: "Bits3val", new_data: "Bits3val", write_mask: "Bits3val") -> "Bits3val":	1✔
216	"""
217	:return: an updated value current_data which has bytes defined by write_mask updated from new_data
218	"""
219	m = byte_mask_to_bit_mask(write_mask)	×
220	return apply_set_and_clear(current_data, new_data & m, m)	×
221
222
223	def extend_to_width_multiple_of_8(v: "Bits3val") -> "Bits3val":	1✔
224	"""
225	make width of signal modulo 8 equal to 0
226	"""
227	w = v._dtype.bit_length()	×
228	cosest_multiple_of_8 = math.ceil((w // 8) / 8) * 8	×
229	if cosest_multiple_of_8 == w:	×
230	return v	×
231	else:
232	return v._ext(cosest_multiple_of_8)	×
233
234
235	def align(val: int, lowerBitCntToAlign: int) -> int:	1✔
236	"""
237	Cut off lower bits to align a int value.
238	"""
239	val = val >> lowerBitCntToAlign	1✔
240	return val << lowerBitCntToAlign	1✔
241
242
243	def align_with_known_width(val, width: int, lowerBitCntToAlign: int):	1✔
244	"""
245	Does same as :func:`~.align` just with the known width of val
246	"""
247	return val & (mask(width - lowerBitCntToAlign) << lowerBitCntToAlign)	×
248
249
250	def iter_bits(val: int, length: int) -> Generator[Literal[0, 1], None, None]:	1✔
251	"""
252	Iterate bits in int. LSB first.
253	"""
254	for _ in range(length):	1✔
255	yield val & 1	1✔
256	val >>= 1	1✔
257
258
259	def iter_bits_sequences(val: int, length: int) -> Generator[Tuple[Literal[0, 1], int], None, None]:	1✔
260	"""
261	Iter tuples (bitVal, number of same bits), lsb first
262	"""
263	assert length > 0, length	×
264	assert val >= 0	×
265	# start of new bit seqence
266	w = 1	×
267	valBit = val & 1	×
268	val >>= 1	×
269	foundBit = valBit	×
270	for _ in range(length - 1):	×
271	# extract single bit from val
272	valBit = val & 1	×
273	val >>= 1	×
274	# check if it fits into current bit sequence
275	if valBit == foundBit:	×
276	w += 1	×
277	else:
278	# end of sequence of same bits
279	yield (foundBit, w)	×
280	foundBit = valBit	×
281	w = 1	×
282
283	if w != 0:	×
284	yield (foundBit, w)	×
285
286
287	def to_signed(val: int, width: int) -> int:	1✔
288	"""
289	Convert unsigned int to negative int which has same bits set (emulate sign overflow).
290
291	:note: bits in value are not changed, just python int object
292	has signed flag set properly. And number is in expected range.
293	"""
294	if val > 0:	1✔
295	msb = 1 << (width - 1)	1✔
296	if val & msb:	1✔
297	val -= mask(width) + 1	1✔
298	return val	1✔
299
300
301	def to_unsigned(val, width) -> int:	1✔
302	if val < 0:	1✔
303	return val & mask(width)	1✔
304	else:
305	return val	1✔
306
307
308	def mask_bytes(val: int, byte_mask: int, mask_bit_length: int) -> int:	1✔
309	"""
310	Use each bit in byte_mask as a mask for each byte in val.
311
312	:note: Useful for masking of value for HW interfaces where mask
313	is represented by a vector of bits where each bit is mask
314	for byte in data vector.
315	"""
316	res = 0	1✔
317	for i, m in enumerate(iter_bits(byte_mask, mask_bit_length)):	1✔
318	if m:	1✔
319	res \|= (val & 0xff) << (i * 8)	1✔
320	val >>= 8	1✔
321	return res	1✔
322
323
324	INT_BASES = {	1✔
325	"b": 2,
326	"o": 8,
327	"d": 10,
328	"h": 16,
329	}
330
331
332	class ValidityError(ValueError):	1✔
333	"""
334	Value is not fully defined and thus can not be used
335	"""
336
337
338	def normalize_slice(s: slice, obj_width: int) -> Tuple[int, int]:	1✔
339	start, stop, step = s.start, s.stop, s.step	1✔
340	if step is not None and step != -1:	1✔
341	raise NotImplementedError(s.step)
342	else:
343	step = -1	1✔
344	if stop is None:	1✔
345	stop = 0	1✔
346	else:
347	stop = int(stop)	1✔
348
349	if start is None:	1✔
350	start = int(obj_width)	1✔
351	else:
352	start = int(start)	1✔
353	# n...0
354	if start <= stop:	1✔
355	raise IndexError(s)	1✔
356	firstBitNo = stop	1✔
357	size = start - stop	1✔
358	if start < 0 or stop < 0 or size < 0 or start > obj_width:	1✔
359	raise IndexError(s)	1✔
360
361	return firstBitNo, size	1✔
362
363
364	def reverse_bits(val: int, width: int):	1✔
365	"""
366	Reverse bits in integer value of specified width
367	"""
368	v = 0	1✔
369	for i in range(width):	1✔
370	v \|= (get_bit(val, width - i - 1) << i)	1✔
371	return v	1✔
372
373
374	def extend_to_size(collection: Sequence, items: int, pad=0):	1✔
375	toAdd = items - len(collection)	1✔
376	assert toAdd >= 0	1✔
377	for _ in range(toAdd):	1✔
378	collection.append(pad)	1✔
379
380	return collection	1✔
381
382
383	def rotate_right(v: int, width: int, shAmount:int):	1✔
384	# https://www.geeksforgeeks.org/rotate-bits-of-an-integer/
385	assert v >= 0, v	×
386	assert width > 0, width	×
387	assert shAmount >= 0, shAmount	×
388	return (v >> shAmount) \| ((v << (width - shAmount)) & mask(width))	×
389
390
391	def rotate_left(v: int, width: int, shAmount:int):	1✔
392	# https://www.geeksforgeeks.org/rotate-bits-of-an-integer/
393	assert v >= 0, v	×
394	assert width > 0, width	×
395	assert shAmount >= 0, shAmount	×
396	return ((v << shAmount) & mask(width)) \| (v >> (width - shAmount))	×
397
398
399	def bit_list_reversed_endianity(bitList: List[Literal[0, 1]], extend=True):	1✔
400	w = len(bitList)	1✔
401	i = w	1✔
402
403	items: list[Literal[0, 1]] = []	1✔
404	while i > 0:	1✔
405	# take last 8 bits or rest
406	lower = max(i - 8, 0)	1✔
407	b = bitList[lower:i]	1✔
408	if extend:	1!
409	extend_to_size(b, 8)	1✔
410	items.extend(b)	1✔
411	i -= 8	1✔
412
413	return items	1✔
414
415
416	def bit_list_reversed_bits_in_bytes(bitList: List[Literal[0, 1]], extend=None):	1✔
417	"Byte reflection (0x0f -> 0xf0)"
418	w = len(bitList)	1✔
419	if extend is None:	1!
420	assert w % 8 == 0	1✔
421
422	tmp: list[Literal[0, 1]] = []	1✔
423	for db in grouper(8, bitList, padvalue=0):	1✔
424	tmp.extend(reversed(db))	1✔
425
426	if not extend and len(tmp) != w:	1!
427	rem = w % 8	×
428	# rm zeros from [0, 0, 0, 0, 0, d[2], d[1], d[0]] like
429	tmp = tmp[:w - rem] + tmp[-rem:]	×
430
431	return tmp	1✔
432
433
434	def bytes_to_bit_list_lower_bit_first(bytes_: bytes) -> List[Literal[0, 1]]:	1✔
435	"""
436	b'\x01' to [1, 0, 0, 0, 0, 0, 0, 0]
437	"""
438	result: List[Literal[0, 1]] = []	×
439	for byte in bytes_:	×
440	for _ in range(8):	×
441	result.append(byte & 0b1)	×
442	byte >>= 1	×
443	return result	×
444
445
446	def bytes_to_bit_list_upper_bit_first(bytes_: bytes) -> List[Literal[0, 1]]:	1✔
447	"""
448	b'\x01' to [0, 0, 0, 0, 0, 0, 0, 1]
449	"""
450	result: List[Literal[0, 1]] = []	×
451	for byte in bytes_:	×
452	for _ in range(8):	×
453	result.append((byte & 0x80) >> 7)	×
454	byte <<= 1	×
455	return result	×
456
457
458	def byte_list_to_be_int(_bytes: List[Literal[0, 1, 2, 3, 4, 5, 6, 7]]):	1✔
459	"""
460	In input list LSB first, in result little endian ([1, 0] -> 0x0001)
461	"""
462	return int_list_to_int(_bytes, 8)	×
463
464
465	def bit_list_to_int(bitList: List[Literal[0, 1]]):	1✔
466	"""
467	In input list LSB first, in result little endian ([0, 1] -> 0b10)
468	"""
469	res = 0	1✔
470	for i, r in enumerate(bitList):	1✔
471	res \|= (r & 0x1) << i	1✔
472	return res	1✔
473
474
475	def bit_list_to_bytes(bitList: List[Literal[0, 1]]) -> bytes:	1✔
476	byteCnt = len(bitList) // 8	×
477	if len(bitList) % 8:	×
478	byteCnt += 1	×
479	return bit_list_to_int(bitList).to_bytes(byteCnt, 'big')	×
480
481
482	def int_list_to_int(il: List[int], item_width: int):	1✔
483	"""
484	[0x0201, 0x0403] -> 0x04030201
485	"""
486	v = 0	1✔
487	for i, b in enumerate(il):	1✔
488	v \|= b << (i * item_width)	1✔
489
490	return v	1✔
491
492
493	def int_to_int_list(v: int, item_width: int, number_of_items: int):	1✔
494	"""
495	opposite of :func:`~.int_list_to_int`
496	"""
497	item_mask = mask(item_width)	1✔
498	res = []	1✔
499	for _ in range(number_of_items):	1✔
500	res.append(v & item_mask)	1✔
501	v >>= item_width	1✔
502
503	assert v == 0, ("there should be nothing left, the value is larger", v)	1✔
504	return res	1✔
505
506
507	def reverse_byte_order(val: "Bits3val"):	1✔
508	"""
509	Reverse byteorder (littleendian/bigendian) of signal or value
510	"""
511	w = val._dtype.bit_length()	×
512	i = w	×
513	items = []	×
514
515	while i > 0:	×
516	# take last 8 bytes or rest
517	lower = max(i - 8, 0)	×
518	items.append(val[i:lower])	×
519	i -= 8	×
520
521	# Concat(*items)
522	top = None	×
523	for s in items:	×
524	if top is None:	×
525	top = s	×
526	else:
527	top = top._concat(s)	×
528	return top	×
529
530
531	def reverse_byte_order_int(val: int, width: int):	1✔
532	assert width % 8 == 0, width	×
533	return int.from_bytes(val.to_bytes(width // 8, "big"), "little")	×
534
535
536	def is_power_of_2(v: Union["Bits3val", int]):	1✔
537	if isinstance(v, int):	×
538	assert v > 0	×
539	return (v != 0) & (clear_least_significant_1(v) == 0)	×
540	else:
541	return (v != 0) & (clear_least_significant_1(v)._eq(0))	×
542
543
544	def next_power_of_2(v: Union["Bits3val", int], width:Optional[int]=None):	1✔
545	# depend on the fact that v < 2^width
546	v = v - 1	×
547	if isinstance(v, int):	×
548	if v < 0:	×
549	assert width is not None	×
550	v = to_unsigned(v, width)	×
551	elif width is None:	×
552	width = v.bit_length() + 1	×
553	else:
554	width = v._dtype.bit_length()	×
555
556	i = 1	×
557	while True:	×
558	v \|= (v >> i) # 1, 2, 4, 8, 16 for 32b	×
559	i <<= 1	×
560	if i > (width // 2):	×
561	break	×
562
563	v = v + 1	×
564
565	if isinstance(v, int):	×
566	v &= mask(width)	×
567
568	return v	×
569
570
571	def round_up_to_multiple_of(v: int, divider:int):	1✔
572	"""
573	Round up the v to be the multiple of divider
574	"""
575	_v = (v // divider) * divider	×
576	if _v < v:	×
577	return _v + divider	×
578	else:
579	return _v	×
580
581
582	def round_up_to_power_of_2(x: int):	1✔
583	assert x >= 0, x	×
584	if x == 0:	×
585	return 0	×
586	return int(2 ** math.ceil(math.log2(x)))	×
587
588
589	def ctlz(val: int, width: int) -> int:	1✔
590	"""
591	Count leading zeros
592	"""
593	if val == 0:	×
594	return width	×
595
596	# Bisection method.
597	ZeroBits = 0	×
598	if not is_power_of_2(width):	×
599	# because alg. works only for pow2 width
600	_w = next_power_of_2(width, 64)	×
601	paddingBits = _w - width	×
602	width = _w	×
603	else:
604	paddingBits = 0	×
605
606	Shift = width >> 1	×
607	while Shift:	×
608	Tmp = val >> Shift	×
609	if Tmp:	×
610	val = Tmp	×
611	else:
612	ZeroBits \|= Shift	×
613	Shift >>= 1	×
614	return ZeroBits - paddingBits	×
615
616
617	def ctlo(val: int, width: int) -> int:	1✔
618	"""
619	Count leading ones
620	"""
NEW 621	return ctlz(~val, width)	×
622
623
624	def _ctpop_u64(v: int) -> int:	1✔
625	v = v - ((v >> 1) & 0x5555555555555555)	×
626	v = (v & 0x3333333333333333) + ((v >> 2) & 0x3333333333333333)	×
627	v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0F	×
628	return (v * 0x0101010101010101) >> 56	×
629
630
631	def ctpop(val: int, width: int):	1✔
632	"""
633	count number of 1 in val (population count)
634	"""
635	res = 0	×
636	mask_u64 = mask(64)	×
637	while True:	×
638	res += _ctpop_u64(val & mask_u64)	×
639	width -= 64	×
640	if width <= 0:	×
641	break	×
642	val >>= 64	×
643	return res	×
644
645
646	def cttz(val: int, width: int):	1✔
647	"""
648	Count trailing zeros
649	"""
650	if val == 0:	×
651	return width	×
652	if val & 0x1:	×
653	return 0	×
654
655	# ctpop method: (x & -x).bit_length() - 1
656	# Bisection method.
657	ZeroBits = 0	×
658	if not is_power_of_2(width):	×
659	width = next_power_of_2(width, 64) # because alg. works only for pow2 width	×
660	Shift = width >> 1	×
661	Mask = mask(width) >> Shift	×
662	while Shift:	×
663	if (val & Mask) == 0:	×
664	val >>= Shift	×
665	ZeroBits \|= Shift	×
666
667	Shift >>= 1	×
668	Mask >>= Shift	×
669
670	return ZeroBits	×
671
672
673	def ctto(val: int):	1✔
674	"""
675	Count trailing ones
676	"""
NEW 677	return cttz(~val, val.bit_length())	×

Nic30 / pyMathBitPrecise / 697bca74-2893-4324-97a5-dd0e956ca48b

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