1 files changed, 97 insertions, 0 deletions
diff --git a/usr/src/lib/libm/common/R/scalbnf.c b/usr/src/lib/libm/common/R/scalbnf.c
new file mode 100644
index 0000000000..fab79011fc
--- /dev/null
+++ b/usr/src/lib/libm/common/R/scalbnf.c
@@ -0,0 +1,97 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+ */
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#if defined(ELFOBJ)
+#pragma weak scalbnf = __scalbnf
+#endif
+
+#include "libm.h"
+#include <float.h>		/* FLT_MAX, FLT_MIN */
+#include <stdlib.h>		/* abs */
+
+static const float twom25f = 2.98023223876953125e-8F;
+#if defined(USE_FPSCALE) || defined(__x86)
+static const float two23f = 8388608.0F;
+#else
+/*
+ * v: a non-zero subnormal |x|; returns [-22, 0]
+ */
+static int
+ilogbf_biased(unsigned v) {
+	int r = -22;
+
+	if (v & 0xffff0000)
+		r += 16, v >>= 16;
+	if (v & 0xff00)
+		r += 8, v >>= 8;
+	if (v & 0xf0)
+		r += 4, v >>= 4;
+	v <<= 1;
+	return (r + ((0xffffaa50 >> v) & 0x3));
+}
+#endif	/* defined(USE_FPSCALE) */
+
+float
+scalbnf(float x, int n) {
+	int *px = (int *) &x, ix, k;
+
+	ix = *px & ~0x80000000;
+	k = ix >> 23;
+	if (k == 0xff)
+#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
+		return (ix > 0x7f800000 ? x * x : x);
+#else
+		return (x + x);
+#endif
+	if (ix == 0 || n == 0)
+		return (x);
+	if (k == 0) {
+#if defined(USE_FPSCALE) || defined(__x86)
+		x *= two23f;
+		k = ((*px & ~0x80000000) >> 23) - 23;
+#else
+		k = ilogbf_biased(ix);
+		*px = (*px & 0x80000000) | (ix << (-k + 1));
+#endif
+	}
+	if ((unsigned) abs(n) >= 131072)	/* cast to unsigned for -2^31 */
+		n >>= 1;		/* avoid subsequent integer overflow */
+	k += n;
+	if (k > 0xfe)
+		return (FLT_MAX * copysignf(FLT_MAX, x));
+	if (k <= -25)
+		return (FLT_MIN * copysignf(FLT_MIN, x));
+	if (k > 0) {
+		*px = (*px & ~0x7f800000) | (k << 23);
+		return (x);
+	}
+	k += 25;
+	*px = (*px & ~0x7f800000) | (k << 23);
+	return (x * twom25f);
+}