Github user ueshin commented on a diff in the pull request:

    https://github.com/apache/spark/pull/15480#discussion_r89802303
  
    --- Diff: 
sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/GenerateOrdering.scala
 ---
    @@ -118,7 +118,42 @@ object GenerateOrdering extends 
CodeGenerator[Seq[SortOrder], Ordering[InternalR
               }
           """
         }.mkString("\n")
    -    comparisons
    +
    +    /*
    +     * 40 = 7000 bytes / 170 (around 170 bytes per ordering comparison).
    +     * The maximum byte code size to be compiled for HotSpot is 8000 bytes.
    +     * We should keep less than 8000 bytes.
    +     */
    +    val numberOfComparisonsThreshold = 40
    +
    +    if (ordering.size <= numberOfComparisonsThreshold) {
    +      comparisons(ordering)
    +    } else {
    +      val groupedOrderingItr = 
ordering.grouped(numberOfComparisonsThreshold)
    +      val funcNamePrefix = ctx.freshName("compare")
    +      val funcNames = groupedOrderingItr.zipWithIndex.map { case 
(orderingGroup, i) =>
    +        val funcName = s"${funcNamePrefix}_$i"
    +        val funcCode =
    +          s"""
    +             |private int $funcName(InternalRow a, InternalRow b) {
    +             |  InternalRow ${ctx.INPUT_ROW} = null;  // Holds current row 
being evaluated.
    +             |  ${comparisons(orderingGroup)}
    +             |  return 0;
    --- End diff --
    
    I'm interested in refactoring approach, which will be useful for more 
general case.


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