implementing another way of doing Autotuning (using bisection)

bioem.cpp

@@ -526,6 +526,9 @@ int bioem::run()
   int workload = getenv("GPUWORKLOAD") == NULL ? 100 : atoi(getenv("GPUWORKLOAD"));
   int best_workload = workload;
   bool stopTuning=false;
+  int a=1, b=50, c=100, x=75, limit=1;
+  double fb=0., fx=0.;
+  if (Autotuning == 3) rebalance(b);
 
   if (DebugOutput >= 1 && mpi_rank == 0) printf("\tMain Loop GridAngles %d, CTFs %d, RefMaps %d, Shifts (%d/%d)², Pixels %d², OMP Threads %d, MPI Ranks %d\n", param.nTotGridAngles, param.nTotCTFs, RefMap.ntotRefMap, 2 * param.param_device.maxDisplaceCenter + param.param_device.GridSpaceCenter, param.param_device.GridSpaceCenter, param.param_device.NumberPixels, omp_get_max_threads(), mpi_size);
 
@@ -636,6 +639,42 @@ int bioem::run()
 		    }
 		  rebalance(workload);
 		}
+	      if (Autotuning == 3 && !stopTuning && (iConv % 7 == 6))
+		{
+		  if (compTime == 0.) compTime = timer.GetCurrentElapsedTime();
+
+		  if (iOrient == iOrientStart && iConv == 6)
+		    {
+		      fb = compTime;
+		      x = 75;
+		    }
+		  else
+		    {
+		      fx = compTime;
+		      if (fx < fb)
+			{
+			if (x < b)
+			  c = b;
+			else
+			  a = b;
+			b = x;
+			fb = fx;
+			}
+		      else
+			{
+			if (x < b)
+			  a = x;
+			else
+			  c = x;
+			}
+		      x = (c-b > b-a) ? (int)(b+(c-b)/2) : (int)(a+(b-a)/2);
+
+		    }
+
+		  if ( (c-b == limit) && ( b-a == limit) ) stopTuning=true;
+
+		  rebalance(x);
+		}
 	    }
 	  if (DebugOutput >= 1)
 	    {