[SubZero] Fix code generation issues occurred in Cross-test and PNaCL smoke-tests

src/IcePhiLoweringImpl.h

 //===------ subzero/src/IcePhiLoweringImpl.h - Phi lowering -----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 18 matching lines @@
 /// assumes the 32-bit target has loOperand, hiOperand, and legalizeUndef
 /// methods. Undef values are also legalized, since loOperand() and hiOperand()
 /// don't expect Undef input.
 template <class TargetT>
 void prelowerPhis32Bit(TargetT *Target, CfgNode *Node, Cfg *Func) {
   for (Inst &I : Node->getPhis()) {
     auto *Phi = llvm::dyn_cast<InstPhi>(&I);
     if (Phi->isDeleted())
       continue;
     Variable *Dest = Phi->getDest();
-    if (Dest->getType() == IceType_i64) {
+    Type DestTy = Dest->getType();
+    if (DestTy == IceType_i64) {
       auto *DestLo = llvm::cast<Variable>(Target->loOperand(Dest));
       auto *DestHi = llvm::cast<Variable>(Target->hiOperand(Dest));
       auto *PhiLo = InstPhi::create(Func, Phi->getSrcSize(), DestLo);
       auto *PhiHi = InstPhi::create(Func, Phi->getSrcSize(), DestHi);
       for (SizeT I = 0; I < Phi->getSrcSize(); ++I) {
         Operand *Src = Phi->getSrc(I);
         CfgNode *Label = Phi->getLabel(I);
         Src = Target->legalizeUndef(Src);
         PhiLo->addArgument(Target->loOperand(Src), Label);
         PhiHi->addArgument(Target->hiOperand(Src), Label);
       }
       Node->getPhis().push_back(PhiLo);
       Node->getPhis().push_back(PhiHi);
       Phi->setDeleted();
+    } else if (isVectorType(DestTy) &&
+               Target->shouldSplitToVariableVecOn32(DestTy)) {
+      auto *DstVec = llvm::cast<VariableVecOn32>(Dest);
+      SizeT Idx = 0;
+      for (Variable *DestElem : DstVec->getContainers()) {
+        auto *PhiElem = InstPhi::create(Func, Phi->getSrcSize(), DestElem);
+        for (SizeT I = 0; I < Phi->getSrcSize(); ++I) {
+          Operand *Src = Phi->getSrc(I);
+          CfgNode *Label = Phi->getLabel(I);
+          Src = Target->legalizeUndef(Src);
+          auto *SrcVec = llvm::cast<VariableVecOn32>(Src);
+          PhiElem->addArgument(SrcVec->getContainers()[Idx], Label);
+        }
+        ++Idx;
+        Node->getPhis().push_back(PhiElem);
+      }
+      Phi->setDeleted();
     }
   }
 }
 
 } // end of namespace PhiLowering
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEPHILOWERINGIMPL_H