d9d2683f-3145-4e9b-8b48-211fa8a4cd64

Committed 13 Sep 2025 11:03AM UTC coverage: 66.688% (+0.3%) from 66.371%

Build # d9d2683f-3145-4e9b-8b48-211fa8a4cd64

Build Type

push

circleci

Committed by

Nic30

Commit Message

feat(bit_utils): least significant bits manipulation utils

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Branch coverage included in aggregate %.

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46.14

/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 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 = []
    while i > 0:
        # take last 8 bytes 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 = []
    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):
        assert width is not None
        v = to_unsigned(v, width)
    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 _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

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

Nic30 / pyMathBitPrecise / d9d2683f-3145-4e9b-8b48-211fa8a4cd64

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