reducing gen code size

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateSafeProjection.scala

@@ -52,17 +52,43 @@ object GenerateSafeProjection extends CodeGenerator[Seq[Expression], Projection]
     ctx.addMutableState("Object[]", values, s"this.$values = null;")
 
     val rowClass = classOf[GenericInternalRow].getName
-
-    val fieldWriters = schema.map(_.dataType).zipWithIndex.map { case (dt, i) =>
-      val converter = convertToSafe(ctx, ctx.getValue(tmp, dt, i.toString), dt)
+    val isHomogenousStruct = {
+      var i = 1
+      val ref =  ctx.javaType(schema.fields(0).dataType)
+      var broken = false || !ctx.isPrimitiveType(ref) || schema.length <=1
+      while( !broken && i < schema.length) {
+        if(ctx.javaType(schema.fields(i).dataType) != ref) {
+          broken = true
+        }
+        i +=1
+      }
+      !broken
+    }
+    val allFields =  if(isHomogenousStruct) {
+      val counter = ctx.freshName("counter")
+      val converter = convertToSafe(ctx, ctx.getValue(tmp, schema.fields(0).dataType, counter), schema.fields(0).dataType)
       s"""
+          for(int $counter = 0; $counter < ${schema.length}; ++$counter) {
+           if (!$tmp.isNullAt($counter)) {
+              ${converter.code}
+              $values[$counter] = ${converter.value};
+            }
+          }
+      """
+
+    }else {
+      val fieldWriters = schema.map(_.dataType).zipWithIndex.map { case (dt, i) =>
+        val converter = convertToSafe(ctx, ctx.getValue(tmp, dt, i.toString), dt)
+        s"""
         if (!$tmp.isNullAt($i)) {
           ${converter.code}
           $values[$i] = ${converter.value};
         }
       """
+      }
+      ctx.splitExpressions(tmp, fieldWriters)
     }
-    val allFields = ctx.splitExpressions(tmp, fieldWriters)
+
     val code = s"""
       final InternalRow $tmp = $input;
       this.$values = new Object[${schema.length}];

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateUnsafeProjection.scala

@@ -112,7 +112,7 @@ object GenerateUnsafeProjection extends CodeGenerator[Seq[Expression], UnsafePro
             val isHomogenousStruct = {
               var i = 1
               val ref =  ctx.javaType(t.fields(0).dataType)
-              var broken = false || !ctx.isPrimitiveType(ref) || t.length <=1 || input.isNull != "false"
+              var broken = false || !ctx.isPrimitiveType(ref) || t.length <=1
               while( !broken && i < t.length) {
                 if(ctx.javaType(t.fields(i).dataType) != ref) {
                   broken = true