29 lines
887 B
Python
29 lines
887 B
Python
# Copyright 2023-2024 (C) Peter McGoron
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#
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# This file is a part of Upsilon, a free and open source software project.
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# For license terms, refer to the files in `doc/copying` in the Upsilon
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# source distribution.
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def minbits(n):
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""" Return the amount of bits necessary to store n. """
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from math import log2, floor
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return floor(log2(n) + 1)
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def round_up_to_pow_2(n):
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""" Round up to nearest power of 2 if not already a power of 2. """
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assert n > 0
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# If n is a power of 2, then n - 1 has a smaller bit length than n.
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# If n is not a power of 2, then n - 1 has the same bit length.
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l = (n - 1).bit_length()
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return 1 << (l + 1)
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def round_up_to_word(n):
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""" Round up to 8, 16, or 32. """
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if n <= 8:
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return 8
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if n <= 16:
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return 16
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if n <= 32:
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return 32
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raise Exception(f"{n} must be less than or equal to 32")
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