Modify the float4 datatype to be pass-by-val. Along the way, remove the last

uses of the long-deprecated float32 in contrib/seg; the definitions themselves
are still there, but no longer used.  fmgr/README updated to match.

I added a CREATE FUNCTION to account for existing seg_center() code in seg.c
too, and some tests for it and the neighbor functions.  At the same time,
remove checks for NULL which are not needed (because the functions are declared
STRICT).

I had to do some adjustments to contrib's btree_gist too.  The choices for
representation there are not ideal for changing the underlying types :-(

Original patch by Zoltan Boszormenyi, with some adjustments by me.

1 files changed, 6 insertions, 2 deletions

diff --git a/contrib/btree_gist/btree_utils_num.c b/contrib/btree_gist/btree_utils_num.c
index 9798d015635..c7b41f16c1e 100644
--- a/contrib/btree_gist/btree_utils_num.c
+++ b/contrib/btree_gist/btree_utils_num.c
@@ -13,10 +13,11 @@ gbt_num_compress(GISTENTRY *retval, GISTENTRY *entry, const gbtree_ninfo * tinfo
 		{
 			int16		i2;
 			int32		i4;
+			float4		f4;
 			DateADT		dt;
 		}			v;
 
-		GBT_NUMKEY *r = (GBT_NUMKEY *) palloc(2 * tinfo->size);
+		GBT_NUMKEY *r = (GBT_NUMKEY *) palloc0(2 * tinfo->size);
 		void	   *leaf = NULL;
 
 		switch (tinfo->t)
@@ -37,11 +38,14 @@ gbt_num_compress(GISTENTRY *retval, GISTENTRY *entry, const gbtree_ninfo * tinfo
 				v.dt = DatumGetDateADT(entry->key);
 				leaf = &v.dt;
 				break;
+			case gbt_t_float4:
+				v.f4 = DatumGetFloat4(entry->key);
+				leaf = &v.f4;
+				break;
 			default:
 				leaf = DatumGetPointer(entry->key);
 		}
 
-		memset((void *) &r[0], 0, 2 * tinfo->size);
 		memcpy((void *) &r[0], leaf, tinfo->size);
 		memcpy((void *) &r[tinfo->size], leaf, tinfo->size);
 		retval = palloc(sizeof(GISTENTRY));