cpu: generate SimPoint basic block vector profiles

This patch is based on http://reviews.m5sim.org/r/1474/ originally written by
Mitch Hayenga. Basic block vectors are generated (simpoint.bb.gz in simout
folder) based on start and end addresses of basic blocks.

Some comments to the original patch are addressed and hooks are added to create
and resume from checkpoints based on instruction counts dictated by external
SimPoint analysis tools.

SimPoint creation/resuming options will be implemented as a separate patch.

configs/example/se.py

@@ -166,6 +166,13 @@ if options.fastmem:
     if (options.caches or options.l2cache):
         fatal("You cannot use fastmem in combination with caches!")
 
+if options.simpoint_profile:
+    if not options.fastmem:
+        # Atomic CPU checked with fastmem option already
+        fatal("SimPoint generation should be done with atomic cpu and fastmem")
+    if np > 1:
+        fatal("SimPoint generation not supported with more than one CPUs")
+
 for i in xrange(np):
     if options.smt:
         system.cpu[i].workload = multiprocesses
@@ -177,6 +184,10 @@ for i in xrange(np):
     if options.fastmem:
         system.cpu[i].fastmem = True
 
+    if options.simpoint_profile:
+        system.cpu[i].simpoint_profile = True
+        system.cpu[i].simpoint_interval = options.simpoint_interval
+
     if options.checker:
         system.cpu[i].addCheckerCpu()