4e484ca33e
Partially reverts: https://gem5-review.googlesource.com/c/public/gem5/+/29372 where the `math.ceil` function was used to fix an issue where 0.5 was rounded to zero in python3. This has the side effect of giving incorrect clock frequences due to rounding errors. To demonstrate: ``` >>> import math >>> 1e-9*1000000000000 1000.0000000000001 >>> int(math.ceil(1e-9*1000000000000)) 1001 ``` The solution to this problem is to use Python's `decimal` module to round values. Issue-on: https://gem5.atlassian.net/browse/GEM5-616 Signed-off-by: Hoa Nguyen <hoanguyen@ucdavis.edu> Change-Id: Ic76736ccb4b6b8c037103a34493aff7d9731d314 Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/29577 Reviewed-by: Tiago Mück <tiago.muck@arm.com> Maintainer: Jason Lowe-Power <power.jg@gmail.com> Tested-by: kokoro <noreply+kokoro@google.com>
87 lines
3.2 KiB
Python
87 lines
3.2 KiB
Python
# Copyright (c) 2007 The Regents of The University of Michigan
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# All rights reserved.
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#
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions are
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# met: redistributions of source code must retain the above copyright
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# notice, this list of conditions and the following disclaimer;
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# redistributions in binary form must reproduce the above copyright
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# notice, this list of conditions and the following disclaimer in the
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# documentation and/or other materials provided with the distribution;
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# neither the name of the copyright holders nor the names of its
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# contributors may be used to endorse or promote products derived from
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# this software without specific prior written permission.
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#
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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from __future__ import print_function
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import decimal
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import six
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if six.PY3:
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long = int
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import sys
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from m5.util import warn
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# fix the global frequency
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def fixGlobalFrequency():
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import _m5.core
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_m5.core.fixClockFrequency()
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def setGlobalFrequency(ticksPerSecond):
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from m5.util import convert
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import _m5.core
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if isinstance(ticksPerSecond, (int, long)):
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tps = ticksPerSecond
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elif isinstance(ticksPerSecond, float):
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tps = ticksPerSecond
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elif isinstance(ticksPerSecond, str):
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tps = round(convert.anyToFrequency(ticksPerSecond))
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else:
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raise TypeError(
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"wrong type '%s' for ticksPerSecond" % type(ticksPerSecond))
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_m5.core.setClockFrequency(int(tps))
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# how big does a rounding error need to be before we warn about it?
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frequency_tolerance = 0.001 # 0.1%
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def fromSeconds(value):
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import _m5.core
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if not isinstance(value, float):
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raise TypeError("can't convert '%s' to type tick" % type(value))
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# once someone needs to convert to seconds, the global frequency
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# had better be fixed
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if not _m5.core.clockFrequencyFixed():
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raise AttributeError(
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"In order to do conversions, the global frequency must be fixed")
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if value == 0:
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return 0
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# convert the value from time to ticks
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value *= _m5.core.getClockFrequency()
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int_value = int(
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decimal.Decimal(value).to_integral_value( decimal.ROUND_HALF_UP))
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err = (value - int_value) / value
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if err > frequency_tolerance:
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warn("rounding error > tolerance\n %f rounded to %d", value,
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int_value)
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return int_value
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__all__ = [ 'setGlobalFrequency', 'fixGlobalFrequency', 'fromSeconds',
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'frequency_tolerance' ]
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