/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
 */
/*
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma weak __lrintl = lrintl

#include <sys/isa_defs.h>       /* _ILP32 */
#include "libm.h"

#if defined(_ILP32)
#if defined(__sparc)

#include "fma.h"
#include "fenv_inlines.h"

long
lrintl(long double x) {
        union {
                unsigned int i[4];
                long double q;
        } xx;
        union {
                unsigned int i;
                float f;
        } tt;
        unsigned int hx, sx, frac, l, fsr;
        int rm, j;
        volatile float dummy;

        xx.q = x;
        sx = xx.i[0] & 0x80000000;
        hx = xx.i[0] & ~0x80000000;

        /* handle trivial cases */
        if (hx > 0x401e0000) { /* |x| > 2^31 + ... or x is nan */
                /* convert an out-of-range float */
                tt.i = sx | 0x7f000000;
                return ((long) tt.f);
        } else if ((hx | xx.i[1] | xx.i[2] | xx.i[3]) == 0) /* x is zero */
                return (0L);

        /* get the rounding mode */
        __fenv_getfsr32(&fsr);
        rm = fsr >> 30;

        /* flip the sense of directed roundings if x is negative */
        if (sx)
                rm ^= rm >> 1;

        /* handle |x| < 1 */
        if (hx < 0x3fff0000) {
                dummy = 1.0e30F; /* x is nonzero, so raise inexact */
                dummy += 1.0e-30F;
                if (rm == FSR_RP || (rm == FSR_RN && (hx >= 0x3ffe0000 &&
                        ((hx & 0xffff) | xx.i[1] | xx.i[2] | xx.i[3]))))
                        return (sx ? -1L : 1L);
                return (0L);
        }

        /* extract the integer and fractional parts of x */
        j = 0x406f - (hx >> 16);                /* 91 <= j <= 112 */
        xx.i[0] = 0x10000 | (xx.i[0] & 0xffff);
        if (j >= 96) {                          /* 96 <= j <= 112 */
                l = xx.i[0] >> (j - 96);
                frac = ((xx.i[0] << 1) << (127 - j)) | (xx.i[1] >> (j - 96));
                if (((xx.i[1] << 1) << (127 - j)) | xx.i[2] | xx.i[3])
                        frac |= 1;
        } else {                                /* 91 <= j <= 95 */
                l = (xx.i[0] << (96 - j)) | (xx.i[1] >> (j - 64));
                frac = (xx.i[1] << (96 - j)) | (xx.i[2] >> (j - 64));
                if ((xx.i[2] << (96 - j)) | xx.i[3])
                        frac |= 1;
        }

        /* round */
        if (frac && (rm == FSR_RP || (rm == FSR_RN && (frac > 0x80000000U ||
                (frac == 0x80000000 && (l & 1))))))
                l++;

        /* check for result out of range (note that z is |x| at this point) */
        if (l > 0x80000000U || (l == 0x80000000U && !sx)) {
                tt.i = sx | 0x7f000000;
                return ((long) tt.f);
        }

        /* raise inexact if need be */
        if (frac) {
                dummy = 1.0e30F;
                dummy += 1.0e-30F;
        }

        /* negate result if need be */
        if (sx)
                l = -l;
        return ((long) l);
}
#elif defined(__x86)
long
lrintl(long double x) {
        /*
         * Note: The following code works on x86 (in the default rounding
         * precision mode), but one ought to just use the fistpl instruction
         * instead.
         */
        union {
                unsigned i[3];
                long double e;
        } xx, yy;
        int ex;

        xx.e = x;
        ex = xx.i[2] & 0x7fff;
        if (ex < 0x403e) {      /* |x| < 2^63 */
                /* add and subtract a power of two to round x to an integer */
                yy.i[2] = (xx.i[2] & 0x8000) | 0x403e;
                yy.i[1] = 0x80000000;
                yy.i[0] = 0;
                x = (x + yy.e) - yy.e;
        }

        /* now x is nan, inf, or integral */
        return ((long) x);
}
#else
#error Unknown architecture
#endif  /* defined(__sparc) || defined(__x86) */
#else
#error Unsupported architecture
#endif  /* defined(_ILP32) */