25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER START
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * The contents of this file are subject to the terms of the
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Common Development and Distribution License (the "License").
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You may not use this file except in compliance with the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * or http://www.opensolaris.org/os/licensing.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * See the License for the specific language governing permissions
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * and limitations under the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER END
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Use is subject to license terms.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * The following implementation assumes fast 64-bit integer arith-
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * metic. This is fine for sparc because we build libm in v8plus
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * mode. It's also fine for sparcv9 and amd64, although we have
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * assembly code on amd64. For x86, it would be better to use
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * 32-bit code, but we have assembly for x86, too.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis hx = *(long long *)&x;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis iy = *(long long *)&y & ~0x8000000000000000ull;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* handle special cases */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (ix >= 0x7ff0000000000000ll || iy > 0x7ff0000000000000ll)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return ((x * y) * zero);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * ny = true exponent of y
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * nd = true exponent of x minus true exponent of y
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * ix = normalized significand of x
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * iy = normalized significand of y
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* y is subnormal, x could be normal or subnormal */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ix = 0x0010000000000000ll | (ix & 0x000fffffffffffffll);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* both x and y are normal */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ix = 0x0010000000000000ll | (ix & 0x000fffffffffffffll);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis iy = 0x0010000000000000ll | (iy & 0x000fffffffffffffll);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* perform fixed point mod */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* convert back to floating point and restore the sign */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis while (ix > 0x0020000000000000ll) { /* XXX can this ever happen? */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis /* result is subnormal */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *(long long *)&w = (hx & 0x8000000000000000ull) | ix;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *(long long *)&w = (hx & 0x8000000000000000ull) |
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ((long long)ny << 52) | (ix & 0x000fffffffffffffll);