common/m9x/nearbyintl.c

25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * CDDL HEADER START
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
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25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis * Common Development and Distribution License (the "License").
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25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis *
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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
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#pragma weak nearbyintl = __nearbyintl
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "libm.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "fma.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#include "fenv_inlines.h"
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#if defined(__sparc)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisstatic union {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    unsigned i;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    float f;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis} snan = { 0x7f800001 };
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtislong double
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis__nearbyintl(long double x) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    union {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        unsigned i[4];
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        long double q;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } xx;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    unsigned hx, sx, i, frac;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    unsigned int fsr;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    int rm, j;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    volatile float  dummy;
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 is nan, inf, or already integral */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        /* check for signaling nan */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if ((hx > 0x7fff0000 || (hx == 0x7fff0000 &&
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            (xx.i[1] | xx.i[2] | xx.i[3]))) && !(hx & 0x8000)) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            dummy = snan.f;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            dummy += snan.f;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] = sx | hx | 0x8000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (xx.q);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else if ((hx | xx.i[1] | xx.i[2] | xx.i[3]) == 0) /* x is zero */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* get the rounding mode */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    __fenv_getfsr32(&fsr);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    rm = fsr >> 30;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* flip the sense of directed roundings if x is negative */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (sx)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        rm ^= rm >> 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* handle |x| < 1 */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (hx < 0x3fff0000) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (rm == FSR_RP || (rm == FSR_RN && (hx >= 0x3ffe0000 &&
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            ((hx & 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]))))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] = sx | 0x3fff0000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] = sx;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[1] = xx.i[2] = xx.i[3] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        return (xx.q);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* round x at the integer bit */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    j = 0x406f - (hx >> 16);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    if (j >= 96) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        i = 1 << (j - 96);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        frac = ((xx.i[0] << 1) << (127 - j)) | (xx.i[1] >> (j - 96));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if ((xx.i[1] & (i - 1)) | xx.i[2] | xx.i[3])
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            frac |= 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (!frac)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[1] = xx.i[2] = xx.i[3] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[0] &= ~(i - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            (frac == 0x80000000 && (xx.i[0] & i)))))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[0] += i;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else if (j >= 64) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        i = 1 << (j - 64);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        frac = ((xx.i[1] << 1) << (95 - j)) | (xx.i[2] >> (j - 64));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if ((xx.i[2] & (i - 1)) | xx.i[3])
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            frac |= 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (!frac)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[2] = xx.i[3] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[1] &= ~(i - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            (frac == 0x80000000 && (xx.i[1] & i))))) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[1] += i;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[1] == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                xx.i[0]++;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else if (j >= 32) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        i = 1 << (j - 32);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        frac = ((xx.i[2] << 1) << (63 - j)) | (xx.i[3] >> (j - 32));
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (xx.i[3] & (i - 1))
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            frac |= 1;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (!frac)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[3] = 0;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[2] &= ~(i - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            (frac == 0x80000000 && (xx.i[2] & i))))) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[2] += i;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[2] == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                if (++xx.i[1] == 0)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis                    xx.i[0]++;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        }
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    } else {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        i = 1 << j;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        frac = (xx.i[3] << 1) << (31 - j);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (!frac)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            return (x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        xx.i[3] &= ~(i - 1);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis        if (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000u ||
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            (frac == 0x80000000 && (xx.i[3] & i))))) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            xx.i[3] += i;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis            if (xx.i[3] == 0)
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    return (xx.q);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#elif defined(__x86)
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis/* inline template */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtisextern long double frndint(long double);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtislong double
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis__nearbyintl(long double x) {
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    long double z;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    unsigned oldcwsw, cwsw;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /* save the control and status words, mask the inexact exception */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    __fenv_getcwsw(&oldcwsw);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    cwsw = oldcwsw | 0x00200000;
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    __fenv_setcwsw(&cwsw);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    z = frndint(x);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    /*
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis     * restore the control and status words, preserving all but the
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis     * inexact flag
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis     */
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    __fenv_getcwsw(&cwsw);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    oldcwsw |= (cwsw & 0x1f);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    __fenv_setcwsw(&oldcwsw);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis    return (z);
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis}
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#else
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#error Unknown architecture
25c28e83beb90e7c80452a7c818c5e6f73a07dc8Piotr Jasiukajtis#endif