Enable Linear Scan RA by default to test

Enable Linear Scan RA by default to test

Author: bcheng0127

visa/LinearScanRA.cpp

@@ -1551,8 +1551,7 @@ void LinearScanRA::calculateCurrentBBLiveIntervals(
         liveIntervals.push_back(stackCallRetLR);
         stackCallRetLR->setPushed(true);
       }
-      if (arg && argSize > 0 && arg->getRegVar()) {
-        vASSERT(stackCallArgLR);
+      if (stackCallArgLR && arg && argSize > 0 && arg->getRegVar()) {
         stackCallArgLR->setLastRef(
             curInst, curInst->getLexicalId() * 2 -
                          1); // Minus one so that arguments will not be spilled

visa/LocalRA.cpp

@@ -2021,6 +2021,15 @@ void PhyRegsLocalRA::markPhyRegs(G4_Declare *topdcl) {
       for (unsigned int i = 0; i < numwords; i++) {
         // Starting from first word, mark each consecutive word busy
         setWordBusy(regnum, (subRegInWord + i));
+
+        //In case across one GRF
+        if (subRegInWord + i >= builder.numEltPerGRF<Type_UW>()) {
+          regnum++;
+          if (!isGRFAvailable(regnum)) {
+            break;
+          }
+          i = 0;
+        }
       }
     }
   } else {