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Diffstat (limited to 'usr/src/lib/libm/common/m9x/round.c')
-rw-r--r--usr/src/lib/libm/common/m9x/round.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/usr/src/lib/libm/common/m9x/round.c b/usr/src/lib/libm/common/m9x/round.c
new file mode 100644
index 0000000000..f4f5a48f2f
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+++ b/usr/src/lib/libm/common/m9x/round.c
@@ -0,0 +1,76 @@
+/*
+ * 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 round = __round
+#endif
+
+#include "libm.h"
+
+double
+round(double x) {
+ union {
+ unsigned i[2];
+ double d;
+ } xx;
+ unsigned hx, sx, i;
+
+ xx.d = x;
+ hx = xx.i[HIWORD] & ~0x80000000;
+ sx = xx.i[HIWORD] & 0x80000000;
+ if (hx < 0x43300000) { /* |x| < 2^52 */
+ if (hx < 0x3ff00000) { /* |x| < 1 */
+ if (hx >= 0x3fe00000)
+ return (sx ? -1.0 : 1.0);
+ return (sx ? -0.0 : 0.0);
+ }
+
+ /* round x at the integer bit */
+ if (hx < 0x41300000) {
+ i = 1 << (0x412 - (hx >> 20));
+ xx.i[HIWORD] = (xx.i[HIWORD] + i) & ~(i | (i - 1));
+ xx.i[LOWORD] = 0;
+ } else {
+ i = 1 << (0x432 - (hx >> 20));
+ xx.i[LOWORD] += i;
+ if (xx.i[LOWORD] < i)
+ xx.i[HIWORD]++;
+ xx.i[LOWORD] &= ~(i | (i - 1));
+ }
+ return (xx.d);
+ } else if (hx < 0x7ff00000)
+ return (x);
+ else
+#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
+ return (hx >= 0x7ff80000 ? x : x + x);
+ /* assumes sparc-like QNaN */
+#else
+ return (x + x);
+#endif
+}