cpu: Add a IsPseudo StaticInstFlag for gem5 pseudo-ops

Being able to recognise pseudo ops from the static instruction
pointer is actually quite useful in several circumstances

Change-Id: Ib39badf9aabba15ab3ebe7a8e9717583412731e4
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>

src/cpu/StaticInstFlags.py

@@ -1,4 +1,14 @@
-# Copyright (c) 2020 ARM Limited
+# Copyright (c) 2020, 2023 Arm Limited
+#
+# The license below extends only to copyright in the software and shall
+# not be construed as granting a license to any other intellectual
+# property including but not limited to intellectual property relating
+# to a hardware implementation of the functionality of the software
+# licensed hereunder.  You may use the software subject to the license
+# terms below provided that you ensure that this notice is replicated
+# unmodified and in its entirety in all distributions of the software,
+# modified or unmodified, in source code or in binary form.
+#
 # Copyright (c) 2003-2005 The Regents of The University of Michigan
 # Copyright (c) 2013 Advanced Micro Devices, Inc.
 # All rights reserved.
@@ -75,6 +85,7 @@ class StaticInstFlags(Enum):
         "IsNonSpeculative",  # Should not be executed speculatively
         "IsQuiesce",  # Is a quiesce instruction
         "IsUnverifiable",  # Can't be verified by a checker
+        "IsPseudo",  # Is a gem5 pseudo-op
         "IsSyscall",  # Causes a system call to be emulated in syscall
         # emulation mode.
         # Flags for microcode

src/cpu/static_inst.hh

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2020 ARM Limited
+ * Copyright (c) 2017, 2020, 2023 Arm Limited
  * Copyright (c) 2022-2023 The University of Edinburgh
  * All rights reserved
  *
@@ -182,6 +182,7 @@ class StaticInst : public RefCounted, public StaticInstFlags
     bool isNonSpeculative() const { return flags[IsNonSpeculative]; }
     bool isQuiesce() const { return flags[IsQuiesce]; }
     bool isUnverifiable() const { return flags[IsUnverifiable]; }
+    bool isPseudo() const { return flags[IsPseudo]; }
     bool isSyscall() const { return flags[IsSyscall]; }
     bool isMacroop() const { return flags[IsMacroop]; }
     bool isMicroop() const { return flags[IsMicroop]; }