Subzero: Use scalar arithmetic when no vector instruction exists.

src/IceTargetLoweringX8632.h

Index: src/IceTargetLoweringX8632.h
diff --git a/src/IceTargetLoweringX8632.h b/src/IceTargetLoweringX8632.h
index 0c87beed167fdf06d8286e3b61f9ae53ae90f564..2b189ad402ce082637c6857a0e993e0a9322d0ab 100644
--- a/src/IceTargetLoweringX8632.h
+++ b/src/IceTargetLoweringX8632.h
@@ -122,6 +122,9 @@ protected:
 
   void eliminateNextVectorSextInstruction(Variable *SignExtendedResult);
 
+  void scalarizeArithmetic(InstArithmetic::OpKind K, Variable *Dest,
+                           Operand *Src0, Operand *Src1);
+
   // Operand legalization helpers.  To deal with address mode
   // constraints, the helpers will create a new Operand and emit
   // instructions that guarantee that the Operand kind is one of those
@@ -220,8 +223,8 @@ protected:
   void _bswap(Variable *SrcDest) {
     Context.insert(InstX8632Bswap::create(Func, SrcDest));
   }
-  void _cdq(Variable *Dest, Operand *Src0) {
-    Context.insert(InstX8632Cdq::create(Func, Dest, Src0));
+  void _cbwdq(Variable *Dest, Operand *Src0) {
+    Context.insert(InstX8632Cbwdq::create(Func, Dest, Src0));
   }
   void _cmov(Variable *Dest, Operand *Src0, InstX8632::BrCond Condition) {
     Context.insert(InstX8632Cmov::create(Func, Dest, Src0, Condition));