- Track register pressure more accurately when there are

partially-written local variables.

- Fixes a crash in liveness

Change-Id: I1d1540defc3516a23964f5954cfefef77a1f37df

Author: wpan

visa/LocalScheduler/G4_Sched.cpp

@@ -303,11 +303,16 @@ struct RegisterPressure
         }
     }
 
+    RegisterPressure(const RegisterPressure& other) = delete;
+    RegisterPressure& operator=(RegisterPressure& other) = delete;
+
     void init()
     {
         p2a = new PointsToAnalysis(kernel.Declares, kernel.fg.getNumBB());
         p2a->doPointsToAnalysis(kernel.fg);
         gra = new GlobalRA(kernel, kernel.fg.builder->phyregpool, *p2a);
+        // To properly track liveness for partially-written local variables.
+        gra->markGraphBlockLocalVars(/*doLocalRA*/false);
         liveness = new LivenessAnalysis(*gra, G4_GRF | G4_ADDRESS | G4_INPUT | G4_FLAG);
         liveness->computeLiveness(true);
         rpe = new RPE(*gra, liveness);
@@ -382,11 +387,6 @@ struct RegisterPressure
         }
         std::cerr << "\n\n";
     }
-    private:
-        // Private copy ctor, assignment operator to prevent shallow copy that
-        // could lead to double free.
-        RegisterPressure(const RegisterPressure& other);
-        RegisterPressure& operator=(RegisterPressure& other);
 };
 
 struct SchedConfig

visa/RPE.cpp

@@ -42,9 +42,12 @@ namespace vISA
     void RPE::run()
     {
         startTimer(TIMER_RPE);
-        for (auto& bb : gra.kernel.fg.BBs)
+        if (liveAnalysis->getNumSelectedVar() > 0)
         {
-            runBB(bb);
+            for (auto& bb : gra.kernel.fg.BBs)
+            {
+                runBB(bb);
+            }
         }
         stopTimer(TIMER_RPE);
     }