diff --git a/src/test/regress/expected/float8.out b/src/test/regress/expected/float8.out
index 7aed4aa97f8..e85f92ce198 100644
--- a/src/test/regress/expected/float8.out
+++ b/src/test/regress/expected/float8.out
@@ -454,24 +454,25 @@ SELECT '' AS five, * FROM FLOAT8_TBL;
       | -1.2345678901234e-200
 (5 rows)
 
-RESET extra_float_digits;
 -- hyperbolic functions
+-- we run these with extra_float_digits = 0 too, since different platforms
+-- tend to produce results that vary in the last place.
 SELECT sinh(float8 '1');
-        sinh        
---------------------
- 1.1752011936438014
+      sinh       
+-----------------
+ 1.1752011936438
 (1 row)
 
 SELECT cosh(float8 '1');
-        cosh        
---------------------
- 1.5430806348152437
+       cosh       
+------------------
+ 1.54308063481524
 (1 row)
 
 SELECT tanh(float8 '1');
-        tanh        
---------------------
- 0.7615941559557649
+       tanh        
+-------------------
+ 0.761594155955765
 (1 row)
 
 SELECT asinh(float8 '1');
@@ -481,17 +482,115 @@ SELECT asinh(float8 '1');
 (1 row)
 
 SELECT acosh(float8 '2');
-       acosh        
---------------------
- 1.3169578969248166
+      acosh       
+------------------
+ 1.31695789692482
 (1 row)
 
 SELECT atanh(float8 '0.5');
-       atanh        
---------------------
- 0.5493061443340548
+       atanh       
+-------------------
+ 0.549306144334055
 (1 row)
 
+-- test Inf/NaN cases for hyperbolic functions
+SELECT sinh(float8 'infinity');
+   sinh   
+----------
+ Infinity
+(1 row)
+
+SELECT sinh(float8 '-infinity');
+   sinh    
+-----------
+ -Infinity
+(1 row)
+
+SELECT sinh(float8 'nan');
+ sinh 
+------
+  NaN
+(1 row)
+
+SELECT cosh(float8 'infinity');
+   cosh   
+----------
+ Infinity
+(1 row)
+
+SELECT cosh(float8 '-infinity');
+   cosh   
+----------
+ Infinity
+(1 row)
+
+SELECT cosh(float8 'nan');
+ cosh 
+------
+  NaN
+(1 row)
+
+SELECT tanh(float8 'infinity');
+ tanh 
+------
+    1
+(1 row)
+
+SELECT tanh(float8 '-infinity');
+ tanh 
+------
+   -1
+(1 row)
+
+SELECT tanh(float8 'nan');
+ tanh 
+------
+  NaN
+(1 row)
+
+SELECT asinh(float8 'infinity');
+  asinh   
+----------
+ Infinity
+(1 row)
+
+SELECT asinh(float8 '-infinity');
+   asinh   
+-----------
+ -Infinity
+(1 row)
+
+SELECT asinh(float8 'nan');
+ asinh 
+-------
+   NaN
+(1 row)
+
+SELECT acosh(float8 'infinity');
+  acosh   
+----------
+ Infinity
+(1 row)
+
+SELECT acosh(float8 '-infinity');
+ERROR:  input is out of range
+SELECT acosh(float8 'nan');
+ acosh 
+-------
+   NaN
+(1 row)
+
+SELECT atanh(float8 'infinity');
+ERROR:  input is out of range
+SELECT atanh(float8 '-infinity');
+ERROR:  input is out of range
+SELECT atanh(float8 'nan');
+ atanh 
+-------
+   NaN
+(1 row)
+
+RESET extra_float_digits;
 -- test for over- and underflow
 INSERT INTO FLOAT8_TBL(f1) VALUES ('10e400');
 ERROR:  "10e400" is out of range for type double precision
diff --git a/src/test/regress/sql/float8.sql b/src/test/regress/sql/float8.sql
index 07fbb66c947..8385f3bb7b3 100644
--- a/src/test/regress/sql/float8.sql
+++ b/src/test/regress/sql/float8.sql
@@ -154,15 +154,36 @@ SELECT '' AS bad, f.f1 / '0.0' from FLOAT8_TBL f;
 
 SELECT '' AS five, * FROM FLOAT8_TBL;
 
-RESET extra_float_digits;
-
 -- hyperbolic functions
+-- we run these with extra_float_digits = 0 too, since different platforms
+-- tend to produce results that vary in the last place.
 SELECT sinh(float8 '1');
 SELECT cosh(float8 '1');
 SELECT tanh(float8 '1');
 SELECT asinh(float8 '1');
 SELECT acosh(float8 '2');
 SELECT atanh(float8 '0.5');
+-- test Inf/NaN cases for hyperbolic functions
+SELECT sinh(float8 'infinity');
+SELECT sinh(float8 '-infinity');
+SELECT sinh(float8 'nan');
+SELECT cosh(float8 'infinity');
+SELECT cosh(float8 '-infinity');
+SELECT cosh(float8 'nan');
+SELECT tanh(float8 'infinity');
+SELECT tanh(float8 '-infinity');
+SELECT tanh(float8 'nan');
+SELECT asinh(float8 'infinity');
+SELECT asinh(float8 '-infinity');
+SELECT asinh(float8 'nan');
+SELECT acosh(float8 'infinity');
+SELECT acosh(float8 '-infinity');
+SELECT acosh(float8 'nan');
+SELECT atanh(float8 'infinity');
+SELECT atanh(float8 '-infinity');
+SELECT atanh(float8 'nan');
+
+RESET extra_float_digits;
 
 -- test for over- and underflow
 INSERT INTO FLOAT8_TBL(f1) VALUES ('10e400');