cpu: `Minor' in-order CPU model

This patch contains a new CPU model named `Minor'. Minor models a four
stage in-order execution pipeline (fetch lines, decompose into
macroops, decompose macroops into microops, execute).

The model was developed to support the ARM ISA but should be fixable
to support all the remaining gem5 ISAs. It currently also works for
Alpha, and regressions are included for ARM and Alpha (including Linux
boot).

Documentation for the model can be found in src/doc/inside-minor.doxygen and
its internal operations can be visualised using the Minorview tool
utils/minorview.py.

Minor was designed to be fairly simple and not to engage in a lot of
instruction annotation. As such, it currently has very few gathered
stats and may lack other gem5 features.

Minor is faster than the o3 model. Sample results:

     Benchmark     |   Stat host_seconds (s)
    ---------------+--------v--------v--------
     (on ARM, opt) | simple | o3     | minor
                   | timing | timing | timing
    ---------------+--------+--------+--------
    10.linux-boot  |   169  |  1883  |  1075
    10.mcf         |   117  |   967  |   491
    20.parser      |   668  |  6315  |  3146
    30.eon         |   542  |  3413  |  2414
    40.perlbmk     |  2339  | 20905  | 11532
    50.vortex      |   122  |  1094  |   588
    60.bzip2       |  2045  | 18061  |  9662
    70.twolf       |   207  |  2736  |  1036

1 files changed, 14 insertions, 0 deletions

diff --git a/src/base/trace.hh b/src/base/trace.hh
index dbeffdc8b..eb0ab9dae 100644
--- a/src/base/trace.hh
+++ b/src/base/trace.hh
@@ -72,6 +72,20 @@ struct StringWrap
 
 inline const std::string &name() { return Trace::DefaultName; }
 
+// Interface for things with names. (cf. SimObject but without other
+// functionality).  This is useful when using DPRINTF
+class Named
+{
+  protected:
+    const std::string _name;
+
+  public:
+    Named(const std::string &name_) : _name(name_) { }
+
+  public:
+    const std::string &name() const { return _name; }
+};
+
 //
 // DPRINTF is a debugging trace facility that allows one to
 // selectively enable tracing statements.  To use DPRINTF, there must