# Copyright (c) 2007 The Regents of The University of Michigan
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#
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# redistributions in binary form must reproduce the above copyright
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# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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import decimal

import sys
from m5.util import warn

# fix the global frequency
def fixGlobalFrequency():
    import _m5.core

    _m5.core.fixClockFrequency()


def setGlobalFrequency(ticksPerSecond):
    from m5.util import convert
    import _m5.core

    if isinstance(ticksPerSecond, int):
        tps = ticksPerSecond
    elif isinstance(ticksPerSecond, float):
        tps = ticksPerSecond
    elif isinstance(ticksPerSecond, str):
        tps = round(convert.anyToFrequency(ticksPerSecond))
    else:
        raise TypeError(
            f"wrong type '{type(ticksPerSecond)}' for ticksPerSecond"
        )
    _m5.core.setClockFrequency(int(tps))


# how big does a rounding error need to be before we warn about it?
frequency_tolerance = 0.001  # 0.1%


def fromSeconds(value):
    import _m5.core

    if not isinstance(value, float):
        raise TypeError(f"can't convert '{type(value)}' to type tick")

    # once someone needs to convert to seconds, the global frequency
    # had better be fixed
    if not _m5.core.clockFrequencyFixed():
        raise AttributeError(
            "In order to do conversions, the global frequency must be fixed"
        )

    if value == 0:
        return 0

    # convert the value from time to ticks
    value *= _m5.core.getClockFrequency()

    int_value = int(
        decimal.Decimal(value).to_integral_value(decimal.ROUND_HALF_UP)
    )
    err = (value - int_value) / value
    if err > frequency_tolerance:
        warn(
            "rounding error > tolerance\n    %f rounded to %d",
            value,
            int_value,
        )
    return int_value


__all__ = [
    "setGlobalFrequency",
    "fixGlobalFrequency",
    "fromSeconds",
    "frequency_tolerance",
]