import newlib-2000-02-17 snapshot

1 files changed, 53 insertions, 0 deletions

diff --git a/newlib/libm/common/sf_ilogb.c b/newlib/libm/common/sf_ilogb.c
new file mode 100644
index 000000000..ee65594b1
--- /dev/null
+++ b/newlib/libm/common/sf_ilogb.c
@@ -0,0 +1,53 @@
+/* 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 "fdlibm.h"
+#include <limits.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(hx<0x00800000) {
+	    if(hx==0) 
+		return - INT_MAX;	/* ilogb(0) = 0x80000001 */
+	    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 return INT_MAX;
+}
+
+#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) */