about summary refs log tree commit diff
path: root/sysdeps/ieee754/flt-32/s_logbf.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/ieee754/flt-32/s_logbf.c')
-rw-r--r--sysdeps/ieee754/flt-32/s_logbf.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/sysdeps/ieee754/flt-32/s_logbf.c b/sysdeps/ieee754/flt-32/s_logbf.c
new file mode 100644
index 0000000000..ade892a8f9
--- /dev/null
+++ b/sysdeps/ieee754/flt-32/s_logbf.c
@@ -0,0 +1,40 @@
+/* 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.
+ * ====================================================
+ */
+
+#if defined(LIBM_SCCS) && !defined(lint)
+static char rcsid[] = "$NetBSD: s_logbf.c,v 1.4 1995/05/10 20:47:51 jtc Exp $";
+#endif
+
+#include "math.h"
+#include "math_private.h"
+
+#ifdef __STDC__
+	float __logbf(float x)
+#else
+	float __logbf(x)
+	float x;
+#endif
+{
+	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); 
+}
+weak_alias (__logbf, logbf)