Emulate signbit() if necessary.

diff --git a/ext/POSIX/POSIX.xs b/ext/POSIX/POSIX.xs
index 930b835..923b3d3 100644 (file)
--- a/ext/POSIX/POSIX.xs
+++ b/ext/POSIX/POSIX.xs
@@ -2278,6 +2278,8 @@ fpclassify(x)
        default:
 #ifdef Perl_signbit
            RETVAL = Perl_signbit(x);
+#else
+           RETVAL = (x < 0) || (x == -0.0);
 #endif
            break;
        }

diff --git a/ext/POSIX/t/math.t b/ext/POSIX/t/math.t
index c3232c1..8a15d77 100644 (file)
--- a/ext/POSIX/t/math.t
+++ b/ext/POSIX/t/math.t
@@ -117,9 +117,6 @@ SKIP: {
     cmp_ok(abs(log1p(1e-6) - 9.99999500000333e-07), '<', 1e-9, "log1p");
     cmp_ok(abs(log2(8) - 3), '<', 1e-9, "log2");
   SKIP: {
-      unless ($Config{d_signbit}) {
-          skip "no signbit", 2;
-      }
       is(signbit(2), 0, "signbit 2"); # zero
       ok(signbit(-2), "signbit -2"); # non-zero
     }