Commit Graph

8 Commits

Author SHA1 Message Date
Gabe Black
aa949dba0f cpu: In SimpleIndirectPredictor, avoid an accidental nullptr deref.
The default value of IPredEntry::tag is 0, and if we just blindly
compare the tag we're looking for against this value, we might run into
cases where we match against an uninitialized IPredEntry. In that case,
IPredEntry::target has not been initialized, and if we try to use it in
lookup(...) we'll dereference nullptr and segfault.

To avoid that, we can just add one additional check that makes sure that
not only does the tag of the IPredEntry match, but also that the value
of target is not null, and so the IPredEntry *actually* has tag 0 and
isn't just uninitialized.

Change-Id: I892d0df7c00a0a4cd3ca215fe3a7586ddbca9395
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53403
Maintainer: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2021-11-30 23:29:23 +00:00
Gabe Black
8ef9f70fcb cpu: Use PCStateBase in the branch predictors.
Use PCStateBase instead of TheISA::PCState in the branch predictors.

Change-Id: I0b0867bc09b6191a54d7658813c0b9656c436811
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52055
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Earl Ou <shunhsingou@google.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2021-11-29 22:00:54 +00:00
Daniel R. Carvalho
444cbe6250 cpu: Add a branch_prediction namespace
Encapsulate all branch-prediction-related files
in a branch_prediction namespace. This will allow
these files to be renamed to drop the BP suffix.

Issued-on: https://gem5.atlassian.net/browse/GEM5-982
Change-Id: I640c0caa846a3aade6fae95e9a93e4318ae9fca0
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47303
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
2021-07-07 23:18:59 +00:00
Daniel R. Carvalho
974a47dfb9 misc: Adopt the gem5 namespace
Apply the gem5 namespace to the codebase.

Some anonymous namespaces could theoretically be removed,
but since this change's main goal was to keep conflicts
at a minimum, it was decided not to modify much the
general shape of the files.

A few missing comments of the form "// namespace X" that
occurred before the newly added "} // namespace gem5"
have been added for consistency.

std out should not be included in the gem5 namespace, so
they weren't.

ProtoMessage has not been included in the gem5 namespace,
since I'm not familiar with how proto works.

Regarding the SystemC files, although they belong to gem5,
they actually perform integration between gem5 and SystemC;
therefore, it deserved its own separate namespace.

Files that are automatically generated have been included
in the gem5 namespace.

The .isa files currently are limited to a single namespace.
This limitation should be later removed to make it easier
to accomodate a better API.

Regarding the files in util, gem5:: was prepended where
suitable. Notice that this patch was tested as much as
possible given that most of these were already not
previously compiling.

Change-Id: Ia53d404ec79c46edaa98f654e23bc3b0e179fe2d
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/46323
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2021-07-01 19:08:24 +00:00
Gabe Black
d05a0a4ea1 misc: Delete the now unnecessary create methods.
Most create() methods are no longer necessary. This change deletes them,
and occasionally moves some code from them into the constructors they
call.

Change-Id: Icbab29ba280144b892f9b12fac9e29a0839477e5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/36536
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2020-10-30 04:00:20 +00:00
Gabe Black
91d83cc8a1 misc: Standardize the way create() constructs SimObjects.
The create() method on Params structs usually instantiate SimObjects
using a constructor which takes the Params struct as a parameter
somehow. There has been a lot of needless variation in how that was
done, making it annoying to pass Params down to base classes. Some of
the different forms were:

const Params &
Params &
Params *
const Params *
Params const*

This change goes through and fixes up every constructor and every
create() method to use the const Params & form. We use a reference
because the Params struct should never be null. We use const because
neither the create method nor the consuming object should modify the
record of the parameters as they came in from the config. That would
make consuming them not idempotent, and make it impossible to tell what
the actual simulation configuration was since it would change from any
user visible form (config script, config.ini, dot pdf output).

Change-Id: I77453cba52fdcfd5f4eec92dfb0bddb5a9945f31
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/35938
Reviewed-by: Gabe Black <gabeblack@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2020-10-14 12:06:44 +00:00
Gabe Black
6687265fe2 cpu: Delete authors lists from the cpu directory.
Change-Id: Icfba8e23b5f6820a6ddefe1a50abbe5f8825b7b5
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/25444
Maintainer: Gabe Black <gabeblack@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
2020-02-17 21:51:23 +00:00
Jairo Balart
0473f8f65f cpu: Make the indirect predictor into a SimObject
Change-Id: Ice6549773def7d3e944fae450d4a079bc351e2ba
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/15319
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
2019-05-13 11:43:50 +00:00