localRA: Fix bug when input variable occupies EOT registers

Local RA cannot handle the EOT live range interference, because EOT
variables are handled seperately.
The solution is the if EOT register is occupied by input variable, fail
local RA and use global RA to handle. Global RA can do spill/fill to the
EOT variables.

Author: bcheng0127

visa/LocalRA.cpp

@@ -676,6 +676,31 @@ bool LocalRA::assignUniqueRegisters(bool twoBanksRA, bool twoDirectionsAssign,
       if (dclLR && dclLR->isEOT() && builder.hasEOTGRFBinding()) {
         // For EOT use r112 - r127
         // for simplicity we assign each EOT source unique GRFs
+        int rows = dcl->getNumRows();
+        bool found = false;
+        while (nextEOTGRF + rows <= kernel.getNumRegTotal()) {
+          bool isGood = true;
+          for (int i = 0; i < dcl->getNumRows(); i++) {
+            // Only handle it when the register is available.
+            // If occupied by input, it will only be set busy.
+            // If not avaialable(Such as vISA_Debug) keep the old way.
+            if (pregs->isGRFAvailable(nextEOTGRF + i)) {
+              if (pregs->isGRFBusy(nextEOTGRF + i)) {
+                nextEOTGRF = nextEOTGRF + i + 1;
+                isGood = false;
+                break;
+              }
+            }
+          }
+          if (isGood) {
+            found = true;
+            break;
+          }
+        }
+        if (!found) {
+          return true;
+        }
+
         G4_Greg *phyReg = builder.phyregpool.getGreg(nextEOTGRF);
         dcl->getRegVar()->setPhyReg(phyReg, 0);
         dclLR->setPhyReg(phyReg, 0);