cpu: Dynamically instantiate O3 CPU LSQUnits

Previously, the LSQ would instantiate MaxThreads LSQUnits in the body of it's
object, but it would only initialize numThreads LSQUnits as specified by the
user. This had the effect of leaving some LSQUnits uninitialized when the
number of threads was less than MaxThreads, and when adding statistics to the
LSQUnit that must be initialized, this caused the stats initialization check to
fail. By dynamically instantiating LSQUnits, they are all initialized and this
avoids uninitialized LSQUnits from floating around during runtime.

src/cpu/o3/lsq.hh

@@ -70,6 +70,9 @@ class LSQ {
 
     /** Constructs an LSQ with the given parameters. */
     LSQ(O3CPU *cpu_ptr, IEW *iew_ptr, DerivO3CPUParams *params);
+    ~LSQ() {
+        if (thread) delete [] thread;
+    }
 
     /** Returns the name of the LSQ. */
     std::string name() const;
@@ -316,7 +319,7 @@ class LSQ {
     LSQPolicy lsqPolicy;
 
     /** The LSQ units for individual threads. */
-    LSQUnit thread[Impl::MaxThreads];
+    LSQUnit *thread;
 
     /** List of Active Threads in System. */
     std::list<ThreadID> *activeThreads;

src/cpu/o3/lsq_impl.hh

@@ -61,6 +61,8 @@ LSQ<Impl>::LSQ(O3CPU *cpu_ptr, IEW *iew_ptr, DerivO3CPUParams *params)
       numThreads(params->numThreads),
       retryTid(-1)
 {
+    assert(numThreads > 0 && numThreads <= Impl::MaxThreads);
+
     //**********************************************/
     //************ Handle SMT Parameters ***********/
     //**********************************************/
@@ -109,6 +111,7 @@ LSQ<Impl>::LSQ(O3CPU *cpu_ptr, IEW *iew_ptr, DerivO3CPUParams *params)
     }
 
     //Initialize LSQs
+    thread = new LSQUnit[numThreads];
     for (ThreadID tid = 0; tid < numThreads; tid++) {
         thread[tid].init(cpu, iew_ptr, params, this,
                          maxLQEntries, maxSQEntries, tid);