added tag v1_9_0_4

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/tags/v1_9_0_4@18845 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 69 insertions, 0 deletions

diff --git a/trunk/missing/isinf.c b/trunk/missing/isinf.c
new file mode 100644
index 0000000000..4aef51b213
--- /dev/null
+++ b/trunk/missing/isinf.c
@@ -0,0 +1,69 @@
+/* public domain rewrite of isinf(3) */
+
+#ifdef __osf__
+
+#define _IEEE 1
+#include <nan.h>
+
+int
+isinf(double n)
+{
+    if (IsNANorINF(n) && IsINF(n)) {
+	return 1;
+    }
+    else {
+	return 0;
+    }
+}
+
+#else
+
+#include "ruby/config.h"
+
+#if defined(HAVE_FINITE) && defined(HAVE_ISNAN)
+
+#include <math.h>
+#ifdef HAVE_IEEEFP_H
+#include <ieeefp.h>
+#endif
+
+/* 
+ * isinf may be provided only as a macro.
+ * ex. HP-UX, Solaris 10
+ * http://www.gnu.org/software/automake/manual/autoconf/Function-Portability.html
+ */
+#ifndef isinf
+int
+isinf(double n)
+{
+    return (!finite(n) && !isnan(n));
+}
+#endif
+
+#else
+
+#ifdef HAVE_STRING_H
+# include <string.h>
+#else
+# include <strings.h>
+#endif
+
+static double zero(void) { return 0.0; }
+static double one (void) { return 1.0; }
+static double inf (void) { return one() / zero(); }
+
+int
+isinf(double n)
+{
+    static double pinf = 0.0;
+    static double ninf = 0.0;
+
+    if (pinf == 0.0) {
+	pinf = inf();
+	ninf = -pinf;
+    }
+    return memcmp(&n, &pinf, sizeof n) == 0
+	|| memcmp(&n, &ninf, sizeof n) == 0;
+}
+#endif
+#endif