common/m9x/roundl.c

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
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25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * and limitations under the License.
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
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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 __roundl = roundl
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "libm.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#if defined(__sparc)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtislong double
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisroundl(long double x) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    union {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        unsigned i[4];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        long double q;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } xx;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    unsigned hx, sx, v;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    int j;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    xx.q = x;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    sx = xx.i[0] & 0x80000000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    hx = xx.i[0] & ~0x80000000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* handle trivial cases */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (hx >= 0x406f0000) /* |x| >= 2^112 + ... or x is nan */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (hx >= 0x7fff0000 ? x + x : x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* handle |x| < 1 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (hx < 0x3fff0000) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (hx >= 0x3ffe0000)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (sx ? -1.0L : 1.0L);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (sx ? -0.0L : 0.0L);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    xx.i[0] = hx;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    j = 0x406f - (hx >> 16);        /* 1 <= j <= 112 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (j >= 96) {              /* 96 <= j <= 112 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        v = (1U << (j - 96)) >> 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[0] & v)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                xx.i[0] += v;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] &= ~(v - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        } else if (xx.i[1] & 0x80000000)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                ++xx.i[0];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[1] = xx.i[2] = xx.i[3] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else if (j >= 64) {           /* 64 <= j <= 95 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        v = (1U << (j - 64)) >> 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[1] & v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                xx.i[1] += v;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                if (xx.i[1] < v)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                    ++xx.i[0];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[1] &= ~(v - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        } else if (xx.i[2] & 0x80000000) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                if (++xx.i[1] == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                    ++xx.i[0];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[2] = xx.i[3] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else if (j >= 32) {           /* 32 <= j <= 63 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        v = (1U << (j - 32)) >> 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[2] & v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                xx.i[2] += v;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                if (xx.i[2] < v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                    if (++xx.i[1] == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                        ++xx.i[0];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[2] &= ~(v - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        } else if (xx.i[3] & 0x80000000) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                if (++xx.i[2] == 0) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                    if (++xx.i[1] == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                        ++xx.i[0];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[3] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else {                /* 1 <= j <= 31 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        v = 1U << (j - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (xx.i[3] & v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[3] += v;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[3] < v) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                if (++xx.i[2] == 0) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                    if (++xx.i[1] == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                        ++xx.i[0];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[3] &= ~(v - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* negate result if need be */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (sx)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[0] |= 0x80000000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    return (xx.q);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#elif defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtislong double
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisroundl(long double x) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    union {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        unsigned i[3];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        long double e;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } xx;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    int ex, sx, i;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    xx.e = x;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    ex = xx.i[2] & 0x7fff;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    sx = xx.i[2] & 0x8000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (ex < 0x403e) {  /* |x| < 2^63 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (ex < 0x3fff) {  /* |x| < 1 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (ex >= 0x3ffe)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                return (sx ? -1.0L : 1.0L);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (sx ? -0.0L : 0.0L);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        /* round x at the integer bit */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (ex < 0x401e) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            i = 1 << (0x401d - ex);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[1] = (xx.i[1] + i) & ~(i | (i - 1));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        } else {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            i = 1 << (0x403d - ex);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] += i;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[0] < i)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                xx.i[1]++;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] &= ~(i | (i - 1));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (xx.i[1] == 0) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[2] = sx | ++ex;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[1] = 0x80000000U;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (xx.e);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else if (ex < 0x7fff) /* x is integral */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    else            /* inf or nan */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (x + x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#error Unknown architecture
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#endif  /* defined(__sparc) || defined(__x86) */