initial check-in, version 0.5.0v0.5.0

1 files changed, 31 insertions, 0 deletions

diff --git a/src/math/s_logbf.c b/src/math/s_logbf.c
new file mode 100644
index 00000000..747664d3
--- /dev/null
+++ b/src/math/s_logbf.c
@@ -0,0 +1,31 @@
+/* s_logbf.c -- float version of s_logb.c.
+ * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
+ */
+
+/*
+ * ====================================================
+ * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
+ *
+ * Developed at SunPro, a Sun Microsystems, Inc. business.
+ * Permission to use, copy, modify, and distribute this
+ * software is freely granted, provided that this notice
+ * is preserved.
+ * ====================================================
+ */
+
+#include <math.h>
+#include "math_private.h"
+
+float
+logbf(float x)
+{
+        int32_t ix;
+        GET_FLOAT_WORD(ix,x);
+        ix &= 0x7fffffff;                       /* high |x| */
+        if(ix==0) return (float)-1.0/fabsf(x);
+        if(ix>=0x7f800000) return x*x;
+        if((ix>>=23)==0)                        /* IEEE 754 logb */
+                return -126.0;
+        else
+                return (float) (ix-127);
+}