Inline the easy cases in MakeExpandedObjectReadOnly().

This attempts to buy back some of whatever performance we lost from fixing
bug #14174 by inlining the initial checks in MakeExpandedObjectReadOnly()
into the callers.  We can do that in a macro without creating multiple-
evaluation hazards, so it's pretty much free notationally; and the amount
of code added to callers should be minimal as well.  (Testing a value can't
take many more instructions than passing it to a subroutine.)

Might as well inline DatumIsReadWriteExpandedObject() while we're at it.

This is an ABI break for callers, so it doesn't seem safe to put into 9.5,
but I see no reason not to do it in HEAD.

1 files changed, 10 insertions, 2 deletions

diff --git a/src/include/utils/expandeddatum.h b/src/include/utils/expandeddatum.h
index 9c3b4667310..47989a8cf20 100644
--- a/src/include/utils/expandeddatum.h
+++ b/src/include/utils/expandeddatum.h
@@ -136,6 +136,15 @@ struct ExpandedObjectHeader
 #define EOHPGetRWDatum(eohptr)	PointerGetDatum((eohptr)->eoh_rw_ptr)
 #define EOHPGetRODatum(eohptr)	PointerGetDatum((eohptr)->eoh_ro_ptr)
 
+/* Does the Datum represent a writable expanded object? */
+#define DatumIsReadWriteExpandedObject(d, isnull, typlen) \
+	(((isnull) || (typlen) != -1) ? false : \
+	 VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(d)))
+
+#define MakeExpandedObjectReadOnly(d, isnull, typlen) \
+	(((isnull) || (typlen) != -1) ? (d) : \
+	 MakeExpandedObjectReadOnlyInternal(d))
+
 extern ExpandedObjectHeader *DatumGetEOHP(Datum d);
 extern void EOH_init_header(ExpandedObjectHeader *eohptr,
 				const ExpandedObjectMethods *methods,
@@ -143,8 +152,7 @@ extern void EOH_init_header(ExpandedObjectHeader *eohptr,
 extern Size EOH_get_flat_size(ExpandedObjectHeader *eohptr);
 extern void EOH_flatten_into(ExpandedObjectHeader *eohptr,
 				 void *result, Size allocated_size);
-extern bool DatumIsReadWriteExpandedObject(Datum d, bool isnull, int16 typlen);
-extern Datum MakeExpandedObjectReadOnly(Datum d, bool isnull, int16 typlen);
+extern Datum MakeExpandedObjectReadOnlyInternal(Datum d);
 extern Datum TransferExpandedObject(Datum d, MemoryContext new_parent);
 extern void DeleteExpandedObject(Datum d);