upload sdk

git-svn-id: svn://kolibrios.org@4349 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/newlib/math/sf_ilogb.c

@@ -0,0 +1,55 @@
+/* sf_ilogb.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 "fdlibm.h"
+
+#ifdef __STDC__
+	int ilogbf(float x)
+#else
+	int ilogbf(x)
+	float x;
+#endif
+{
+	__int32_t hx,ix;
+
+	GET_FLOAT_WORD(hx,x);
+	hx &= 0x7fffffff;
+	if(FLT_UWORD_IS_ZERO(hx))
+	    return FP_ILOGB0;	/* ilogb(0) = special case error */
+	if(FLT_UWORD_IS_SUBNORMAL(hx)) {
+	    for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
+	    return ix;
+	}
+	#if FP_ILOGBNAN != INT_MAX
+	else if (FLT_UWORD_IS_NAN(hx)) return FP_ILOGBNAN;	/* NAN */
+	#endif
+	else if (!FLT_UWORD_IS_FINITE(hx)) return INT_MAX;
+	else return (hx>>23)-127;
+}
+
+#ifdef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	int ilogb(double x)
+#else
+	int ilogb(x)
+	double x;
+#endif
+{
+	return ilogbf((float) x);
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */