From db0558c11347ad27a032e6efed509a6e99b52e67 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 12 Jan 2006 19:23:22 +0000
Subject: =?UTF-8?q?Use=20a=20more=20bulletproof=20test=20for=20whether=20f?=
 =?UTF-8?q?inite()=20and=20isinf()=20are=20present.=20It=20seems=20that=20?=
 =?UTF-8?q?recent=20gcc=20versions=20can=20optimize=20away=20calls=20to=20?=
 =?UTF-8?q?these=20functions=20even=20when=20the=20functions=20do=20not=20?=
 =?UTF-8?q?exist=20on=20the=20platform,=20resulting=20in=20a=20bogus=20pos?=
 =?UTF-8?q?itive=20result.=20=20Avoid=20this=20by=20using=20a=20non-consta?=
 =?UTF-8?q?nt=20argument=20and=20ensuring=20that=20the=20function=20result?=
 =?UTF-8?q?=20is=20not=20simply=20discarded.=20=20Per=20report=20from=20Fr?=
 =?UTF-8?q?an=C3=A7ois=20Laupretre.?=
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---
 configure | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

(limited to 'configure')

diff --git a/configure b/configure
index acb4592d8d..0a676a3fd2 100755
--- a/configure
+++ b/configure
@@ -14202,7 +14202,6 @@ fi
 
 
 
-# do this one the hard way in case isinf() is a macro
 echo "$as_me:$LINENO: checking for isinf" >&5
 echo $ECHO_N "checking for isinf... $ECHO_C" >&6
 if test "${ac_cv_func_isinf+set}" = set; then
@@ -14214,12 +14213,14 @@ _ACEOF
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
+
 #include <math.h>
+double glob_double;
 
 int
 main ()
 {
-double x = 0.0; int res = isinf(x);
+return isinf(glob_double) ? 0 : 1;
   ;
   return 0;
 }
@@ -15102,11 +15103,14 @@ _ACEOF
 cat confdefs.h >>conftest.$ac_ext
 cat >>conftest.$ac_ext <<_ACEOF
 /* end confdefs.h.  */
+
 #include <math.h>
+double glob_double;
+
 int
 main ()
 {
-int dummy=finite(1.0);
+return finite(glob_double) ? 0 : 1;
   ;
   return 0;
 }
-- 
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