60 lines
1.2 KiB
Python
60 lines
1.2 KiB
Python
"""
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Cranelift DSL classes.
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This module defines the classes that are used to define Cranelift instructions
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and other entities.
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"""
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from __future__ import absolute_import
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import re
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camel_re = re.compile('(^|_)([a-z])')
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def camel_case(s):
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# type: (str) -> str
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"""Convert the string s to CamelCase:
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>>> camel_case('x')
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'X'
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>>> camel_case('camel_case')
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'CamelCase'
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"""
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return camel_re.sub(lambda m: m.group(2).upper(), s)
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def is_power_of_two(x):
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# type: (int) -> bool
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"""Check if `x` is a power of two:
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>>> is_power_of_two(0)
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False
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>>> is_power_of_two(1)
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True
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>>> is_power_of_two(2)
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True
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>>> is_power_of_two(3)
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False
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"""
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return x > 0 and x & (x-1) == 0
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def next_power_of_two(x):
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# type: (int) -> int
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"""
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Compute the next power of two that is greater than `x`:
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>>> next_power_of_two(0)
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1
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>>> next_power_of_two(1)
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2
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>>> next_power_of_two(2)
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4
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>>> next_power_of_two(3)
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4
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>>> next_power_of_two(4)
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8
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"""
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s = 1
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while x & (x + 1) != 0:
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x |= x >> s
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s *= 2
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return x + 1
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