As described in the Jira issue, this replaces the implementation of
isPowerOf2() and power(). It also revamps floorLog2 so that there only
needs to be one implementation and no assumptions about how big certain
types are.
The way power() used to work was to raise a number n to an exponent e
by multiplying n times itself e times. As a warning in this function
explains, this can be quite slow for large e. A much more efficient
way to raise a number to an exponent is to square n over and over, and
to multiply in the current square if that bit of e is set.
n ^ 15 = (n^1) * (n^2) * (n^4) * (n^8)
n^8 = (n^4)^2
n^4 = (n^2)^2
n^2 = n^2
n^1 = n
So that takes 6 multiplications, n^2, (n^2)^2, (n^4)^2, and then each
multipy to compute the final result, instead of 14.
The difference is more pronounced for larger exponents, although you'd
quickly start to overflow a uint64_t.
Jira Issue: https://gem5.atlassian.net/browse/GEM5-140
Change-Id: I0ae05aeba1b5882d2a616613b1679e6206b4cbfe
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/26164
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The stdio fgetc returns the character read as an unsigned char cast to
an int.
The reason why it gets casted from unsigned char to int is because EOF
is defined as a negative value (usually -1).
At the moment in the atomicio.test we store the int in a char.
However the C standard states that the sign of a char is implementation
specific. This makes the test non portable: an architecture/ABI which
which is considering a char as a unsigned char won't compile since a
unsigned value will always be != -1 (EOF).
This is the error message you would get on a aarch64 host /w gcc/5.4.0
build/ARM/base/atomicio.test.cc:121:48:
error: comparison is always true due to limited range of data type
[-Werror=type-limits]
Change-Id: I120e44b5204d98e643f19b8dd6fa2762342a6e64
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25384
Reviewed-by: Ciro Santilli <ciro.santilli@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Previously the `GTestExitLogger.log` function utilized GTest's
`ADD_FAILURE_AT` macro. This meant, whenever `GTestExitLogger.log` were
called, the calling test would be fail. This is problematic when
trying to test code we expect to fail (i.e., when testing the error
handling code is working correctly). Therefore, the `log` function now
writes to stderr.
The `GTestExitLogger` class is used by the `panic` and `fatal` loggers
when running GTests. Instead of callnig `exit(1)` they throw a GTest
exception, which can be captured in a test using
`EXPECT_ANY_THROW(expection_thrower())`. Catching and verifying error
logs can be done via:
```
testing::internal::CaptureStderr();
/*
* "exception_thrower()" is a method we'd expect to call `fatal` or
* `panic`, and therefore exit the simulation with a non-zero exit
* code. When running via GTest, an exception is thrown instead.
*/
EXPECT_ANY_THROW(exception_thrower());
EXPECT_EQ("<error message>", testing::internal::GetCapturedStderr()));
```
Change-Id: I84a5f86bc573668d3dd5b40f626b43108dddb8e9
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23983
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
amo.hh was using several non-default definitions including
std::function, uint8_t, and std::array without including any headers
at all, and instead apparently relying on those having already been
brought in by an earlier include.
This change adds those includes explicitly.
Change-Id: I92166ff581e74bd705e10fd4fa454df179ae1a97
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/24183
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
The value of the add and subtract assignment operations can be negative,
and this was not being handled properly previously. Regarding shift
assignment, the standard says it is undefined behaviour if a negative
number is given, so add assertions for these cases.
Change-Id: I2f1e4143c6385caa80fb25f84ca8edb0ca7e62b7
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23664
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This is the second step towards being able to run dynamically linked
applications when the guest ISA != than host ISA.
Once the guest interpreter is loaded to memory, we are able to redirect
shared object loads through the redirectPath interface.
How do we load the guest interpreter?
The elf file is for example asking for the /lib/ld-linux-aarch64.so
interpreter.
That would point to a valid dynamic linker/loader if guest ISA == host
ISA, but if we are running on X86 we should point to the guest
(aarch64 in the example) toolchain wherever it is installed.
This patch is adding the --interp-dir option to point to the parent
folder of the guest /lib in the host fs.
Change-Id: Id27b97c060008d2e847776a49323d45c8809a27f
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/23066
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
If FmtTicksOff is given, ticks are disabled for all log messages.
The original motivation of this is to bring the implementation of native
traces closer to that of other traces to help refactoring done in future
patches.
One additional advantage of this is that sometimes we want to compare
traces of a given program under different conditions, so the start of the
ROI is different, and the different initial timestamp makes a diff
useless by showing differences on every line.
Change-Id: Idd6cb105d301b3b9b064996043f4ca75ddafe0af
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22006
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This makes it easier to determine which messages come from which
flags when enabling multiple flags at once.
This commit covers the bulk of the debug messages, which use the DPRINTF*
family of macros. There however macros that use DTRACE to check for
enable, those will be covered in future patches.
Change-Id: I6738b18f08ccfd1e11f2874b426c1827b42e82a2
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22004
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
These tests assume the "end address" is not included in the range. This
exposed some bugs in addr_range.hh which have been fixed. Where
appropriate code comments in addr_range.hh have been extended to improve
understanding of the class's behavior.
Hard-coded AddrRange values in the project have been updated to take
into account that end address is now exclusive. The python params.py
interface has been updated to conform to this new standard.
Change-Id: Idd1e75d5771d198c4b8142b28de0f3a6e9007a52
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22427
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Testing intmath.hh and intmath.cc. Here is the
list of the functions that are tested.
intmath.isPowerOf2, intmath.power, intmath.floorLog2,
intmath.ceilLog2, intmath.divCeil, intmath.roundUp,
intmath.roundDown. Other functions are not tested,
because they are not currently used and are dead code.
Change-Id: I150ac1b5cead93c6698a8c9e9cec80bd87ef181a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22081
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Mahyar Samani <msamani@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
The below list of functions were dead code and are now
deleted.
intmath.prevPrime, intmath.isPrime, intmath.leastSigBit,
intmath.floorPow2, intmath.ceilPow2, intmath.isHex,
intmath.isOct, intmath.isDec, intmath.hex2Int. The source
file intmath.cc is now effectively useless and deleted.
Change-Id: I28e4350056b8d03e02fecd5c7f7f9c62bc2df7ce
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22584
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
The function intmath.leastSigBit is ambiguous given
its name. It does not return the value of the least
significant bit, or the position of the least significant
set bit, but instead 2 to the power of the position of
the least significant set bit. It has thereby been removed
and the function intmath.isPowerOf2 has been refactored to
not require intmath.leastSigBit.
Change-Id: I22479c666cdd059865b8c73b70b5388f98a4584d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22583
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Current loader is performing a linear scan of the section table for
every segment in the elf since it is naming every segment after the
sections it contains. With this patch we are just naming segments
after their index.
This is in any case how they are referenced when a readelf --segments
command is issued on the elf file.
Change-Id: I599400fcdfc0b80ac64632aba36781bd876777f0
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21999
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This abstraction will allow scheduling PCEvents for a particular
ThreadContext, all contexts on a CPU, all contexts in a system, etc.,
and delegates scheduling and removing events to each particular scope.
Right now the PCEventQueue is the only implementor of the PCEventSCope
interface.
Change-Id: I8fb62931511136229915c2e19d36aae7ffdec9df
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22099
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Adding these tests supercedes the unittest/strnumtest.cc
and unittest/tokentest.cc tests. They have thereby been removed.
Function "to_number" in base/str.hh previously failed to cast negative
float/double numbers. This was due to the use of
std::numeric_limits<T>::min() instead of std::numeric_limits<T>::lowest()
to determine whether a string-to-float/double conversion was
"Out of range". Tests "StrTest.ToNumberFloatNegative" and
"StrTest.ToNumberDoubleNegative" exposed this bug. It has been fixed.
Methods "split_first" and "split_last" in base/str.hh have had their
documentation updated to remove abiguity in their functionality.
Change-Id: I16e0fe40d884e22dd010db4045857eb6e7f33d4a
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/22084
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
There are cases where the memory system needs to reason about
channel-local addresses. These are currently represented using the
Addr and AddrRange classes. This is not ideal since it doesn't provide
any type safety when working with global addresses and channel-local
addresses. This is particularly problematic when porting existing
components to work in multi-channel configurations.
This changeset introduces the new ChannelAddr and ChannelAddrRange
classes. These classes encapsulate channel-local addresses in a
contiguous address space. These can, for example, be used in a memory
controller to represent a flat address space when calculating timings
or in a sectored cache.
Change-Id: I45d4061ebc8507a10d0a4577b28796dc5ec7a469
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21600
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>
