Improved HnswNormValue [skip ci]

src/halfvec.c

@@ -94,7 +94,7 @@ pq_sendhalf(StringInfo buf, half h)
 /*
  * Convert a half to a float4
  */
-static float
+float
 HalfToFloat4(half num)
 {
 #ifdef FLT16_SUPPORT
@@ -245,7 +245,7 @@ Float4ToHalfUnchecked(float num)
 /*
  * Convert a float4 to a half
  */
-static half
+half
 Float4ToHalf(float num)
 {
 	half		result = Float4ToHalfUnchecked(num);

src/halfvec.h

@@ -34,5 +34,7 @@ typedef struct HalfVector
 }			HalfVector;
 
 HalfVector *InitHalfVector(int dim);
+float		HalfToFloat4(half num);
+half		Float4ToHalf(float num);
 
 #endif

src/hnswutils.c

@@ -199,7 +199,7 @@ HnswNormValue(FmgrInfo *procinfo, Oid collation, Datum *value, int type)
 			HalfVector *result = InitHalfVector(v->dim);
 
 			for (int i = 0; i < v->dim; i++)
-				result->x[i] = v->x[i] / norm;
+				result->x[i] = Float4ToHalf(HalfToFloat4(v->x[i]) / norm);
 
 			*value = PointerGetDatum(result);
 		}