xref: /titanic_52/usr/src/lib/libm/common/m9x/llroundf.c (revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af)
125c28e83SPiotr Jasiukajtis /*
225c28e83SPiotr Jasiukajtis  * CDDL HEADER START
325c28e83SPiotr Jasiukajtis  *
425c28e83SPiotr Jasiukajtis  * The contents of this file are subject to the terms of the
525c28e83SPiotr Jasiukajtis  * Common Development and Distribution License (the "License").
625c28e83SPiotr Jasiukajtis  * You may not use this file except in compliance with the License.
725c28e83SPiotr Jasiukajtis  *
825c28e83SPiotr Jasiukajtis  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
925c28e83SPiotr Jasiukajtis  * or http://www.opensolaris.org/os/licensing.
1025c28e83SPiotr Jasiukajtis  * See the License for the specific language governing permissions
1125c28e83SPiotr Jasiukajtis  * and limitations under the License.
1225c28e83SPiotr Jasiukajtis  *
1325c28e83SPiotr Jasiukajtis  * When distributing Covered Code, include this CDDL HEADER in each
1425c28e83SPiotr Jasiukajtis  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
1525c28e83SPiotr Jasiukajtis  * If applicable, add the following below this CDDL HEADER, with the
1625c28e83SPiotr Jasiukajtis  * fields enclosed by brackets "[]" replaced with your own identifying
1725c28e83SPiotr Jasiukajtis  * information: Portions Copyright [yyyy] [name of copyright owner]
1825c28e83SPiotr Jasiukajtis  *
1925c28e83SPiotr Jasiukajtis  * CDDL HEADER END
2025c28e83SPiotr Jasiukajtis  */
2125c28e83SPiotr Jasiukajtis 
2225c28e83SPiotr Jasiukajtis /*
2325c28e83SPiotr Jasiukajtis  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
2425c28e83SPiotr Jasiukajtis  */
2525c28e83SPiotr Jasiukajtis /*
2625c28e83SPiotr Jasiukajtis  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
2725c28e83SPiotr Jasiukajtis  * Use is subject to license terms.
2825c28e83SPiotr Jasiukajtis  */
2925c28e83SPiotr Jasiukajtis 
30*ddc0e0b5SRichard Lowe #pragma weak __llroundf = llroundf
3125c28e83SPiotr Jasiukajtis #if defined(__sparcv9) || defined(__amd64)
32*ddc0e0b5SRichard Lowe #pragma weak lroundf = llroundf
33*ddc0e0b5SRichard Lowe #pragma weak __lroundf = llroundf
3425c28e83SPiotr Jasiukajtis #endif
3525c28e83SPiotr Jasiukajtis 
3625c28e83SPiotr Jasiukajtis #include "libm.h"
3725c28e83SPiotr Jasiukajtis 
3825c28e83SPiotr Jasiukajtis long long
3925c28e83SPiotr Jasiukajtis llroundf(float x) {
4025c28e83SPiotr Jasiukajtis 	union {
4125c28e83SPiotr Jasiukajtis 		unsigned i;
4225c28e83SPiotr Jasiukajtis 		float f;
4325c28e83SPiotr Jasiukajtis 	} xx;
4425c28e83SPiotr Jasiukajtis 	unsigned hx, sx, i;
4525c28e83SPiotr Jasiukajtis 
4625c28e83SPiotr Jasiukajtis 	xx.f = x;
4725c28e83SPiotr Jasiukajtis 	hx = xx.i & ~0x80000000;
4825c28e83SPiotr Jasiukajtis 	sx = xx.i & 0x80000000;
4925c28e83SPiotr Jasiukajtis 
5025c28e83SPiotr Jasiukajtis 	if (hx < 0x4b000000) { /* |x| < 2^23 */
5125c28e83SPiotr Jasiukajtis 		/* handle |x| < 1 */
5225c28e83SPiotr Jasiukajtis 		if (hx < 0x3f800000) {
5325c28e83SPiotr Jasiukajtis 			if (hx >= 0x3f000000)
5425c28e83SPiotr Jasiukajtis 				return (sx ? -1LL : 1LL);
5525c28e83SPiotr Jasiukajtis 			return (0LL);
5625c28e83SPiotr Jasiukajtis 		}
5725c28e83SPiotr Jasiukajtis 
5825c28e83SPiotr Jasiukajtis 		/* round x at the integer bit */
5925c28e83SPiotr Jasiukajtis 		i = 1 << (0x95 - (hx >> 23));
6025c28e83SPiotr Jasiukajtis 		xx.i = (xx.i + i) & ~((i << 1) - 1);
6125c28e83SPiotr Jasiukajtis 
6225c28e83SPiotr Jasiukajtis 		/*
6325c28e83SPiotr Jasiukajtis 		 * on LP32 architectures, we can just convert x to a 32-bit
6425c28e83SPiotr Jasiukajtis 		 * integer and sign-extend it
6525c28e83SPiotr Jasiukajtis 		 */
6625c28e83SPiotr Jasiukajtis 		return ((long) xx.f);
6725c28e83SPiotr Jasiukajtis 	}
6825c28e83SPiotr Jasiukajtis 
6925c28e83SPiotr Jasiukajtis 	/* now x is nan, inf, or integral */
7025c28e83SPiotr Jasiukajtis 	return ((long long) x);
7125c28e83SPiotr Jasiukajtis }
72