1 files changed, 37 insertions, 0 deletions
diff --git a/src/math/s_ilogbf.c b/src/math/s_ilogbf.c
new file mode 100644
index 00000000..30359fef
--- /dev/null
+++ b/src/math/s_ilogbf.c
@@ -0,0 +1,37 @@
+/* s_ilogbf.c -- float version of s_ilogb.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 <limits.h>
+
+#include <math.h>
+#include "math_private.h"
+
+int ilogbf(float x)
+{
+        int32_t hx,ix;
+
+        GET_FLOAT_WORD(hx,x);
+        hx &= 0x7fffffff;
+        if(hx<0x00800000) {
+            if(hx==0)
+                return FP_ILOGB0;
+            else                        /* subnormal x */
+                for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
+            return ix;
+        }
+        else if (hx<0x7f800000) return (hx>>23)-127;
+        else if (hx>0x7f800000) return FP_ILOGBNAN;
+        else return INT_MAX;
+}