Configure: signbit scan assuming too much

It was assuming a negative zero, which is an IEEE-754 only concept.

There is no need to assume the negative zero for the correct
functioning of the signbit, however.

diff --git a/Configure b/Configure
index 7c598e9..a68b670 100755 (executable)
--- a/Configure
+++ b/Configure
@@ -18802,7 +18802,7 @@ $cat >try.c <<EOCP
 int main(int argc, char **argv)
 {
     NV x = 0.0;
 int main(int argc, char **argv)
 {
     NV x = 0.0;

-    NV y = -0.0;
+    NV y = -1.0;

     if ((signbit(x) == 0) && (signbit(y) != 0))
        return 0;
     else
     if ((signbit(x) == 0) && (signbit(y) != 0))
        return 0;
     else