tree ebd9f699b92bfa5d7378dfb05052264b8abf32e3
parent a17eb869dc083346c1a03624e28e31cd2635744f
author Gabe Black <gabe.black@gmail.com> 1638180545 -0800
committer Gabe Black <gabe.black@gmail.com> 1638315006 +0000

arch-sparc: Fix a bug in SparcNativeTrace::check.

This method is responsible for comparing gem5's state against the state
of the real process. When checking the value of NPC, it accessed the
value of nnpc() by calling pc.nnpc(), but did not actually update regVal
with it, so the comparison was between the value from the real process
and npc().

It's mildly confusing that nnpc is compared against npc, and npc against
pc, but that's because of what the state looks like in the real process
when single stepping through it with ptrace.

You can actually see where this bug was introduced if you look at the
change which created the PCState types originally. There, you can see
how regVal was set using a method of the ThreadContext, but after that
change the value is only accessed and not actually used.

Change-Id: I0f0101db5f807640b8d25fef6448081d9cfa0213
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/53363
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Boris Shingarov <shingarov@labware.com>
Maintainer: Gabe Black <gabe.black@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>