[query] avoid code explosion for trivial upcasts (#14232)

hail-is · Feb 1, 2024 · 7f12473 · 7f12473
1 parent 171b39d
commit 7f12473
Showing 1 changed file with 10 additions and 6 deletions.
diff --git a/hail/src/main/scala/is/hail/expr/ir/PruneDeadFields.scala b/hail/src/main/scala/is/hail/expr/ir/PruneDeadFields.scala
@@ -2853,12 +2853,16 @@ object PruneDeadFields {
       ir
     else {
       val result = ir.typ match {
-        case _: TStruct =>
-          bindIR(ir) { ref =>
-            val ms = MakeStruct(rType.asInstanceOf[TStruct].fields.map { f =>
-              f.name -> upcast(ctx, GetField(ref, f.name), f.typ)
-            })
-            If(IsNA(ref), NA(ms.typ), ms)
+        case tstruct: TStruct =>
+          if (rType.asInstanceOf[TStruct].fields.forall(f => tstruct.field(f.name).typ == f.typ)) {
+            SelectFields(ir, rType.asInstanceOf[TStruct].fields.map(f => f.name))
+          } else {
+            bindIR(ir) { ref =>
+              val ms = MakeStruct(rType.asInstanceOf[TStruct].fields.map { f =>
+                f.name -> upcast(ctx, GetField(ref, f.name), f.typ)
+              })
+              If(IsNA(ref), NA(ms.typ), ms)
+            }
           }
         case ts: TStream =>
           val ra = rType.asInstanceOf[TStream]