Put back ERANGE test in dpow(). There are platforms that need this,

like my HPPA ...

diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 129405693f2ed9003f4947f3ec6dc332cbca4e37..9cda3706afa4da887246dc6bf8af91edfd856021 100644 (file)
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.142 2007/01/05 22:19:40 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/adt/float.c,v 1.143 2007/01/06 02:28:38 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1442,24 +1442,27 @@ dpow(PG_FUNCTION_ARGS)
         * pow() sets errno only on some platforms, depending on whether it
         * follows _IEEE_, _POSIX_, _XOPEN_, or _SVID_, so we try to avoid
         * using errno.  However, some platform/CPU combinations return
-        * errno == EDOM and result == Nan, so we have to check for that and
-        * set result properly.  For example, Linux on 32-bit x86 hardware
-        * returns EDOM/Nan for (-1) ^ 1e19, but (-1) ^ 1e18 returns
-        * 1 -- basically a negative base raised to a very high power causes
-        * it on some CPUs.
+        * errno == EDOM and result == Nan for negative arg1 and very large arg2
+        * (they must be using something different from our floor() test to
+        * decide it's invalid).  Other platforms return errno == ERANGE and a
+        * large but finite result to signal overflow.
         */
        errno = 0;
        result = pow(arg1, arg2);
        if (errno == EDOM && isnan(result))
        {
                if ((fabs(arg1) > 1 && arg2 >= 0) || (fabs(arg1) < 1 && arg2 < 0))
-                       /* The sign if Inf is not significant in this case. */
+                       /* The sign of Inf is not significant in this case. */
                        result = get_float8_infinity();
                else if (fabs(arg1) != 1)
                        result = 0;
                else
                        result = 1;
        }
+       else if (errno == ERANGE)
+       {
+               result = (arg1 >= 0) ? get_float8_infinity() : -get_float8_infinity();
+       }
        
        CHECKFLOATVAL(result, isinf(arg1) || isinf(arg2), arg1 == 0);
        PG_RETURN_FLOAT8(result);