2.5-18.1

1 files changed, 63 insertions, 0 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/s_ilogbl.c b/sysdeps/ieee754/ldbl-128ibm/s_ilogbl.c
new file mode 100644
index 0000000000..428854d770
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_ilogbl.c
@@ -0,0 +1,63 @@
+/* s_ilogbl.c -- long double version of s_ilogb.c.
+ * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
+ */
+
+/*
+ * ====================================================
+ * 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: $";
+#endif
+
+/* ilogbl(long double x)
+ * return the binary exponent of non-zero x
+ * ilogbl(0) = FP_ILOGB0
+ * ilogbl(NaN) = FP_ILOGBNAN (no signal is raised)
+ * ilogbl(+-Inf) = INT_MAX (no signal is raised)
+ */
+
+#include <limits.h>
+#include "math.h"
+#include "math_private.h"
+#include <math_ldbl_opt.h>
+
+#ifdef __STDC__
+	int __ilogbl(long double x)
+#else
+	int __ilogbl(x)
+	long double x;
+#endif
+{
+	int64_t hx,lx;
+	int ix;
+
+	GET_LDOUBLE_WORDS64(hx,lx,x);
+	hx &= 0x7fffffffffffffffLL;
+	if(hx <= 0x0010000000000000LL) {
+	    if((hx|(lx&0x7fffffffffffffffLL))==0)
+		return FP_ILOGB0;	/* ilogbl(0) = FP_ILOGB0 */
+	    else			/* subnormal x */
+		if(hx==0) {
+		    for (ix = -1043; lx>0; lx<<=1) ix -=1;
+		} else {
+		    for (ix = -1022, hx<<=11; hx>0; hx<<=1) ix -=1;
+		}
+	    return ix;
+	}
+	else if (hx<0x7ff0000000000000LL) return (hx>>52)-0x3ff;
+	else if (FP_ILOGBNAN != INT_MAX) {
+	    /* ISO C99 requires ilogbl(+-Inf) == INT_MAX.  */
+	    if (((hx^0x7ff0000000000000LL)|lx) == 0)
+		return INT_MAX;
+	}
+	return FP_ILOGBNAN;
+}
+long_double_symbol (libm, __ilogbl, ilogbl);