25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER START
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
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 *
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 *
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 *
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER END
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Use is subject to license terms.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
ddc0e0b53c661f6e439e3b7072b3ef353eadb4afRichard Lowe#pragma weak __ilogb = ilogb
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "libm.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "xpg6.h" /* __xpg6 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
1ec68d336ba97cd53f46053ac10401d16014d075Richard Lowe#if defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic const double two52 = 4503599627370496.0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * v: high part of a non-zero subnormal |x|; w: low part of |x|
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic int
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisilogb_subnormal(unsigned v, unsigned w) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis int r = -1022 - 52;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (v)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis r += 32;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis v = w;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (v & 0xffff0000)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis r += 16, v >>= 16;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (v & 0xff00)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis r += 8, v >>= 8;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (v & 0xf0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis r += 4, v >>= 4;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis v <<= 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (r + ((0xffffaa50 >> v) & 0x3));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}
1ec68d336ba97cd53f46053ac10401d16014d075Richard Lowe#endif /* defined(__x86) */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic int
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisraise_invalid(int v) { /* SUSv3 requires ilogb(0,+/-Inf,NaN) raise invalid */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#ifndef lint
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if ((__xpg6 & _C99SUSv3_ilogb_0InfNaN_raises_invalid) != 0) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis static const double zero = 0.0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis volatile double dummy;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis dummy = zero / zero;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#endif
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (v);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisint
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisilogb(double x) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis int *px = (int *) &x, k = px[HIWORD] & ~0x80000000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k < 0x00100000) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if ((px[LOWORD] | k) == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (raise_invalid(0x80000001));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis else {
1ec68d336ba97cd53f46053ac10401d16014d075Richard Lowe#if defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis x *= two52;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (((px[HIWORD] & 0x7ff00000) >> 20) - 1075);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (ilogb_subnormal(k, px[LOWORD]));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#endif
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis } else if (k < 0x7ff00000)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return ((k >> 20) - 1023);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (raise_invalid(0x7fffffff));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}