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/*

 *  ARM helper routines

 * 

 *  Copyright (c) 2005 CodeSourcery, LLC

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include <math.h>

#include <fenv.h>

#include "exec.h"

/* If the host doesn't define C99 math intrinsics then use the normal

   operators.  This may generate excess exceptions, but it's probably

   near enough for most things.  */

#ifndef isless

#define isless(x, y) (x < y)

#endif

#ifndef isgreater

#define isgreater(x, y) (x > y)

#endif

#ifndef isunordered

#define isunordered(x, y) (!((x < y) || (x >= y)))

#endif

void raise_exception(int tt)

{

    env->exception_index = tt;

    cpu_loop_exit();

}

/* thread support */

spinlock_t global_cpu_lock = SPIN_LOCK_UNLOCKED;

void cpu_lock(void)

{

    spin_lock(&global_cpu_lock);

}

void cpu_unlock(void)

{

    spin_unlock(&global_cpu_lock);

}

/* VFP support.  */

void do_vfp_abss(void)

{

  FT0s = fabsf(FT0s);

}

void do_vfp_absd(void)

{

  FT0d = fabs(FT0d);

}

void do_vfp_sqrts(void)

{

  FT0s = sqrtf(FT0s);

}

void do_vfp_sqrtd(void)

{

  FT0d = sqrt(FT0d);

}

/* We use an == operator first to generate teh correct floating point

   exception.  Subsequent comparisons use the exception-safe macros.  */

#define DO_VFP_cmp(p)                     \

void do_vfp_cmp##p(void)                  \

{                                         \

    uint32_t flags;                       \

    if (FT0##p == FT1##p)                 \

        flags = 0xc;                      \

    else if (isless (FT0##p, FT1##p))     \

        flags = 0x8;                      \

    else if (isgreater (FT0##p, FT1##p))  \

        flags = 0x2;                      \

    else /* unordered */                  \

        flags = 0x3;                      \

    env->vfp.fpscr = (flags << 28) | (env->vfp.fpscr & 0x0fffffff); \

    FORCE_RET();                          \

}

DO_VFP_cmp(s)

DO_VFP_cmp(d)

#undef DO_VFP_cmp

/* We use a > operator first to get FP exceptions right.  */

#define DO_VFP_cmpe(p)                      \

void do_vfp_cmpe##p(void)                   \

{                                           \

    uint32_t flags;                         \

    if (FT0##p > FT1##p)                    \

        flags = 0x2;                        \

    else if (isless (FT0##p, FT1##p))       \

        flags = 0x8;                        \

    else if (isunordered (FT0##p, FT1##p))  \

        flags = 0x3;                        \

    else /* equal */                        \

        flags = 0xc;                        \

    env->vfp.fpscr = (flags << 28) | (env->vfp.fpscr & 0x0fffffff); \

    FORCE_RET();                            \

}

DO_VFP_cmpe(s)

DO_VFP_cmpe(d)

#undef DO_VFP_cmpe

/* Convert host exception flags to vfp form.  */

int vfp_exceptbits_from_host(int host_bits)

{

    int target_bits = 0;

#ifdef FE_INVALID

    if (host_bits & FE_INVALID)

        target_bits |= 1;

#endif

#ifdef FE_DIVBYZERO

    if (host_bits & FE_DIVBYZERO)

        target_bits |= 2;

#endif

#ifdef FE_OVERFLOW

    if (host_bits & FE_OVERFLOW)

        target_bits |= 4;

#endif

#ifdef FE_UNDERFLOW

    if (host_bits & FE_UNDERFLOW)

        target_bits |= 8;

#endif

#ifdef FE_INEXACT

    if (host_bits & FE_INEXACT)

        target_bits |= 0x10;

#endif

    /* C doesn't define an inexact exception.  */

    return target_bits;

}

/* Convert vfp exception flags to target form.  */

int vfp_host_exceptbits_to_host(int target_bits)

{

    int host_bits = 0;

#ifdef FE_INVALID

    if (target_bits & 1)

        host_bits |= FE_INVALID;

#endif

#ifdef FE_DIVBYZERO

    if (target_bits & 2)

        host_bits |= FE_DIVBYZERO;

#endif

#ifdef FE_OVERFLOW

    if (target_bits & 4)

        host_bits |= FE_OVERFLOW;

#endif

#ifdef FE_UNDERFLOW

    if (target_bits & 8)

        host_bits |= FE_UNDERFLOW;

#endif

#ifdef FE_INEXACT

    if (target_bits & 0x10)

        host_bits |= FE_INEXACT;

#endif

    return host_bits;

}

void do_vfp_set_fpscr(void)

{

    int i;

    uint32_t changed;

    changed = env->vfp.fpscr;

    env->vfp.fpscr = (T0 & 0xffc8ffff);

    env->vfp.vec_len = (T0 >> 16) & 7;

    env->vfp.vec_stride = (T0 >> 20) & 3;

    changed ^= T0;

    if (changed & (3 << 22)) {

        i = (T0 >> 22) & 3;

        switch (i) {

        case 0:

            i = FE_TONEAREST;

            break;

        case 1:

            i = FE_UPWARD;

            break;

        case 2:

            i = FE_DOWNWARD;

            break;

        case 3:

            i = FE_TOWARDZERO;

            break;

        }

        fesetround (i);

    }

    /* Clear host exception flags.  */

    feclearexcept(FE_ALL_EXCEPT);

#ifdef feenableexcept

    if (changed & 0x1f00) {

        i = vfp_exceptbits_to_host((T0 >> 8) & 0x1f);

        feenableexcept (i);

        fedisableexcept (FE_ALL_EXCEPT & ~i);

    }

#endif

    /* XXX: FZ and DN are not implemented.  */

}

void do_vfp_get_fpscr(void)

{

    int i;

    T0 = (env->vfp.fpscr & 0xffc8ffff) | (env->vfp.vec_len << 16)

          | (env->vfp.vec_stride << 20);

    i = fetestexcept(FE_ALL_EXCEPT);

    T0 |= vfp_exceptbits_from_host(i);

}