upload sdk

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

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

@@ -0,0 +1,62 @@
+/* 2009 for Newlib:  Sun's sf_ilogb.c converted to be sf_logb.c.  */
+/*
+ * ====================================================
+ * 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.
+ * ====================================================
+ */
+
+/* float logb(float x)
+ * return the binary exponent of non-zero x
+ * logbf(0) = -inf, raise divide-by-zero floating point exception
+ * logbf(+inf|-inf) = +inf (no signal is raised)
+ * logbf(NaN) = NaN (no signal is raised)
+ * Per C99 recommendation, a NaN argument is returned unchanged.
+ */
+
+#include "fdlibm.h"
+
+float
+#ifdef __STDC__
+logbf(float x)
+#else
+logbf(x)
+float x;
+#endif
+{
+	__int32_t hx,ix;
+
+	GET_FLOAT_WORD(hx,x);
+	hx &= 0x7fffffff;
+	if(FLT_UWORD_IS_ZERO(hx))  {
+		float  xx;
+		/* arg==0:  return -inf and raise divide-by-zero exception */
+		SET_FLOAT_WORD(xx,hx);	/* +0.0 */
+		return -1./xx;	/* logbf(0) = -inf */
+		}
+	if(FLT_UWORD_IS_SUBNORMAL(hx)) {
+	    for (ix = -126,hx<<=8; hx>0; hx<<=1) ix -=1;
+	    return (float) ix;
+	}
+	else if (FLT_UWORD_IS_INFINITE(hx)) return HUGE_VALF;	/* x==+|-inf */
+	else if (FLT_UWORD_IS_NAN(hx)) return x;
+	else return (float) ((hx>>23)-127);
+}
+
+#ifdef _DOUBLE_IS_32BITS
+
+#ifdef __STDC__
+	double logb(double x)
+#else
+	double logb(x)
+	double x;
+#endif
+{
+	return (double) logbf((float) x);
+}
+
+#endif /* defined(_DOUBLE_IS_32BITS) */