Files
gem5/src/base/fenv.hh
Gabe Black d84123e106 scons,misc: Remove the ability to disable some trivial features.
These are HDF5, PNG, FENV, and TUNTAP support, all of which add
capabilities to gem5 which can be ignored if not wanted. It could be
argued that FENV changes behavior because it makes setting the FP
rounding mode work or not as used by SPARC, but since the difference is
trivial and in a niche area, that (along with the other options) doesn't
seem to justify having a top level control in the build system.

Since these are no longer options which say whether to *use* a
particular feature, and are instead flags which say whether we *have* a
particular feature, change their names from USE_* to HAVE_*, to stay
consistent with other variables.

Most of the remaining USE_* flags, KVM, FASTMODEL, SYSTEMC, and
(indirectly) USE_PYTHON, toggle on and off major systems which can have
a significant effect on boot time, or, in the case of FASTMODEL, even
consume external resources which may not be available and which may
break the build.

USE_POSIX_TIMER was also left alone since it selects between two
implementations of some functions. By forcing it to be on or off
depending on the host, we would be forcing some code to be excluded in
either case. That would make that other code impossible to test without
hacking up scons or modifying the host machine.

Change-Id: I0b03f23e65478caefd50cd3516974386e3dbf0db
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/40964
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2021-05-10 23:32:33 +00:00

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2.1 KiB
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/*
* Copyright (c) 2004-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __BASE_FENV_HH__
#define __BASE_FENV_HH__
#include "config/have_fenv.hh"
namespace gem5
{
enum class RoundingMode
{
Downward = 0,
ToNearest = 1,
TowardZero = 2,
Upward = 3
};
#if HAVE_FENV
void setFpRound(RoundingMode rm);
RoundingMode getFpRound();
#else
// Dummy definitions to allow code to compile w/o a real <fenv.h>.
static inline void setFpRound(RoundingMode rm) {}
static inline
RoundingMode getFpRound()
{
return RoundingMode::Downward;
}
#endif // HAVE_FENV
} // namespace gem5
#endif // __BASE_FENV_HH__