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 __logbf = logbf
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "libm.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "xpg6.h" /* __xpg6 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#define _C99SUSv3_logb _C99SUSv3_logb_subnormal_is_like_ilogb
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
1ec68d336ba97cd53f46053ac10401d16014d075Richard Lowe#if defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic const float two25 = 33554432.0F;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * v: a non-zero subnormal |x|
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic int
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisilogbf_subnormal(unsigned v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis int r = -126 - 23;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
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 float
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisraise_division(float t) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#pragma STDC FENV_ACCESS ON
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis static const float zero = 0.0F;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (t / zero);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisfloat
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtislogbf(float x) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis int k = *((int *) &x) & ~0x80000000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k < 0x00800000) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (raise_division(-1.0F));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis else if ((__xpg6 & _C99SUSv3_logb) != 0) {
1ec68d336ba97cd53f46053ac10401d16014d075Richard Lowe#if defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis x *= two25;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return ((float) (((*((int *) &x) & 0x7f800000) >> 23) -
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis 152));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return ((float) ilogbf_subnormal(k));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#endif
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis } else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (-126.F);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis } else if (k < 0x7f800000)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return ((float) ((k >> 23) - 127));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (x * x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}