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 __scalbnf = scalbnf
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "libm.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <float.h> /* FLT_MAX, FLT_MIN */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include <stdlib.h> /* abs */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic const float twom25f = 2.98023223876953125e-8F;
1ec68d336ba97cd53f46053ac10401d16014d075Richard Lowe#if defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic const float two23f = 8388608.0F;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * v: a non-zero subnormal |x|; returns [-22, 0]
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic int
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisilogbf_biased(unsigned v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis int r = -22;
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 Jasiukajtisfloat
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisscalbnf(float x, int n) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis int *px = (int *) &x, ix, k;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis ix = *px & ~0x80000000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis k = ix >> 23;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k == 0xff)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (ix > 0x7f800000 ? x * x : x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (x + x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#endif
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (ix == 0 || n == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k == 0) {
1ec68d336ba97cd53f46053ac10401d16014d075Richard Lowe#if defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis x *= two23f;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis k = ((*px & ~0x80000000) >> 23) - 23;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis k = ilogbf_biased(ix);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *px = (*px & 0x80000000) | (ix << (-k + 1));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#endif
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if ((unsigned) abs(n) >= 131072) /* cast to unsigned for -2^31 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis n >>= 1; /* avoid subsequent integer overflow */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis k += n;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k > 0xfe)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (FLT_MAX * copysignf(FLT_MAX, x));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k <= -25)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (FLT_MIN * copysignf(FLT_MIN, x));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis if (k > 0) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *px = (*px & ~0x7f800000) | (k << 23);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis k += 25;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *px = (*px & ~0x7f800000) | (k << 23);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis return (x * twom25f);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}