Archipelago » qemu

/*

 *  PowerPC emulation helpers for qemu.

 *

 *  Copyright (c) 2003-2007 Jocelyn Mayer

 *

 * 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, see <http://www.gnu.org/licenses/>.

 */

#include <string.h>

#include "exec.h"

#include "host-utils.h"

#include "helper.h"

#include "helper_regs.h"

//#define DEBUG_OP

//#define DEBUG_EXCEPTIONS

//#define DEBUG_SOFTWARE_TLB

#ifdef DEBUG_SOFTWARE_TLB

#  define LOG_SWTLB(...) qemu_log(__VA_ARGS__)

#else

#  define LOG_SWTLB(...) do { } while (0)

#endif

/*****************************************************************************/

/* Exceptions processing helpers */

void helper_raise_exception_err (uint32_t exception, uint32_t error_code)

{

#if 0

    printf("Raise exception %3x code : %d\n", exception, error_code);

#endif

    env->exception_index = exception;

    env->error_code = error_code;

    cpu_loop_exit();

}

void helper_raise_exception (uint32_t exception)

{

    helper_raise_exception_err(exception, 0);

}

/*****************************************************************************/

/* SPR accesses */

void helper_load_dump_spr (uint32_t sprn)

{

    qemu_log("Read SPR %d %03x => " TARGET_FMT_lx "\n", sprn, sprn,

             env->spr[sprn]);

}

void helper_store_dump_spr (uint32_t sprn)

{

    qemu_log("Write SPR %d %03x <= " TARGET_FMT_lx "\n", sprn, sprn,

             env->spr[sprn]);

}

target_ulong helper_load_tbl (void)

{

    return (target_ulong)cpu_ppc_load_tbl(env);

}

target_ulong helper_load_tbu (void)

{

    return cpu_ppc_load_tbu(env);

}

target_ulong helper_load_atbl (void)

{

    return (target_ulong)cpu_ppc_load_atbl(env);

}

target_ulong helper_load_atbu (void)

{

    return cpu_ppc_load_atbu(env);

}

#if defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY)

target_ulong helper_load_purr (void)

{

    return (target_ulong)cpu_ppc_load_purr(env);

}

#endif

target_ulong helper_load_601_rtcl (void)

{

    return cpu_ppc601_load_rtcl(env);

}

target_ulong helper_load_601_rtcu (void)

{

    return cpu_ppc601_load_rtcu(env);

}

#if !defined(CONFIG_USER_ONLY)

#if defined (TARGET_PPC64)

void helper_store_asr (target_ulong val)

{

    ppc_store_asr(env, val);

}

#endif

void helper_store_sdr1 (target_ulong val)

{

    ppc_store_sdr1(env, val);

}

void helper_store_tbl (target_ulong val)

{

    cpu_ppc_store_tbl(env, val);

}

void helper_store_tbu (target_ulong val)

{

    cpu_ppc_store_tbu(env, val);

}

void helper_store_atbl (target_ulong val)

{

    cpu_ppc_store_atbl(env, val);

}

void helper_store_atbu (target_ulong val)

{

    cpu_ppc_store_atbu(env, val);

}

void helper_store_601_rtcl (target_ulong val)

{

    cpu_ppc601_store_rtcl(env, val);

}

void helper_store_601_rtcu (target_ulong val)

{

    cpu_ppc601_store_rtcu(env, val);

}

target_ulong helper_load_decr (void)

{

    return cpu_ppc_load_decr(env);

}

void helper_store_decr (target_ulong val)

{

    cpu_ppc_store_decr(env, val);

}

void helper_store_hid0_601 (target_ulong val)

{

    target_ulong hid0;

    hid0 = env->spr[SPR_HID0];

    if ((val ^ hid0) & 0x00000008) {

        /* Change current endianness */

        env->hflags &= ~(1 << MSR_LE);

        env->hflags_nmsr &= ~(1 << MSR_LE);

        env->hflags_nmsr |= (1 << MSR_LE) & (((val >> 3) & 1) << MSR_LE);

        env->hflags |= env->hflags_nmsr;

        qemu_log("%s: set endianness to %c => " TARGET_FMT_lx "\n", __func__,

                 val & 0x8 ? 'l' : 'b', env->hflags);

    }

    env->spr[SPR_HID0] = (uint32_t)val;

}

void helper_store_403_pbr (uint32_t num, target_ulong value)

{

    if (likely(env->pb[num] != value)) {

        env->pb[num] = value;

        /* Should be optimized */

        tlb_flush(env, 1);

    }

}

target_ulong helper_load_40x_pit (void)

{

    return load_40x_pit(env);

}

void helper_store_40x_pit (target_ulong val)

{

    store_40x_pit(env, val);

}

void helper_store_40x_dbcr0 (target_ulong val)

{

    store_40x_dbcr0(env, val);

}

void helper_store_40x_sler (target_ulong val)

{

    store_40x_sler(env, val);

}

void helper_store_booke_tcr (target_ulong val)

{

    store_booke_tcr(env, val);

}

void helper_store_booke_tsr (target_ulong val)

{

    store_booke_tsr(env, val);

}

void helper_store_ibatu (uint32_t nr, target_ulong val)

{

    ppc_store_ibatu(env, nr, val);

}

void helper_store_ibatl (uint32_t nr, target_ulong val)

{

    ppc_store_ibatl(env, nr, val);

}

void helper_store_dbatu (uint32_t nr, target_ulong val)

{

    ppc_store_dbatu(env, nr, val);

}

void helper_store_dbatl (uint32_t nr, target_ulong val)

{

    ppc_store_dbatl(env, nr, val);

}

void helper_store_601_batl (uint32_t nr, target_ulong val)

{

    ppc_store_ibatl_601(env, nr, val);

}

void helper_store_601_batu (uint32_t nr, target_ulong val)

{

    ppc_store_ibatu_601(env, nr, val);

}

#endif

/*****************************************************************************/

/* Memory load and stores */

static inline target_ulong addr_add(target_ulong addr, target_long arg)

{

#if defined(TARGET_PPC64)

        if (!msr_sf)

            return (uint32_t)(addr + arg);

        else

#endif

            return addr + arg;

}

void helper_lmw (target_ulong addr, uint32_t reg)

{

    for (; reg < 32; reg++) {

        if (msr_le)

            env->gpr[reg] = bswap32(ldl(addr));

        else

            env->gpr[reg] = ldl(addr);

        addr = addr_add(addr, 4);

    }

}

void helper_stmw (target_ulong addr, uint32_t reg)

{

    for (; reg < 32; reg++) {

        if (msr_le)

            stl(addr, bswap32((uint32_t)env->gpr[reg]));

        else

            stl(addr, (uint32_t)env->gpr[reg]);

        addr = addr_add(addr, 4);

    }

}

void helper_lsw(target_ulong addr, uint32_t nb, uint32_t reg)

{

    int sh;

    for (; nb > 3; nb -= 4) {

        env->gpr[reg] = ldl(addr);

        reg = (reg + 1) % 32;

        addr = addr_add(addr, 4);

    }

    if (unlikely(nb > 0)) {

        env->gpr[reg] = 0;

        for (sh = 24; nb > 0; nb--, sh -= 8) {

            env->gpr[reg] |= ldub(addr) << sh;

            addr = addr_add(addr, 1);

        }

    }

}

/* PPC32 specification says we must generate an exception if

 * rA is in the range of registers to be loaded.

 * In an other hand, IBM says this is valid, but rA won't be loaded.

 * For now, I'll follow the spec...

 */

void helper_lswx(target_ulong addr, uint32_t reg, uint32_t ra, uint32_t rb)

{

    if (likely(xer_bc != 0)) {

        if (unlikely((ra != 0 && reg < ra && (reg + xer_bc) > ra) ||

                     (reg < rb && (reg + xer_bc) > rb))) {

            helper_raise_exception_err(POWERPC_EXCP_PROGRAM,

                                       POWERPC_EXCP_INVAL |

                                       POWERPC_EXCP_INVAL_LSWX);

        } else {

            helper_lsw(addr, xer_bc, reg);

        }

    }

}

void helper_stsw(target_ulong addr, uint32_t nb, uint32_t reg)

{

    int sh;

    for (; nb > 3; nb -= 4) {

        stl(addr, env->gpr[reg]);

        reg = (reg + 1) % 32;

        addr = addr_add(addr, 4);

    }

    if (unlikely(nb > 0)) {

        for (sh = 24; nb > 0; nb--, sh -= 8) {

            stb(addr, (env->gpr[reg] >> sh) & 0xFF);

            addr = addr_add(addr, 1);

        }

    }

}

static void do_dcbz(target_ulong addr, int dcache_line_size)

{

    addr &= ~(dcache_line_size - 1);

    int i;

    for (i = 0 ; i < dcache_line_size ; i += 4) {

        stl(addr + i , 0);

    }

    if (env->reserve_addr == addr)

        env->reserve_addr = (target_ulong)-1ULL;

}

void helper_dcbz(target_ulong addr)

{

    do_dcbz(addr, env->dcache_line_size);

}

void helper_dcbz_970(target_ulong addr)

{

    if (((env->spr[SPR_970_HID5] >> 7) & 0x3) == 1)

        do_dcbz(addr, 32);

    else

        do_dcbz(addr, env->dcache_line_size);

}

void helper_icbi(target_ulong addr)

{

    addr &= ~(env->dcache_line_size - 1);

    /* Invalidate one cache line :

     * PowerPC specification says this is to be treated like a load

     * (not a fetch) by the MMU. To be sure it will be so,

     * do the load "by hand".

     */

    ldl(addr);

}

// XXX: to be tested

target_ulong helper_lscbx (target_ulong addr, uint32_t reg, uint32_t ra, uint32_t rb)

{

    int i, c, d;

    d = 24;

    for (i = 0; i < xer_bc; i++) {

        c = ldub(addr);

        addr = addr_add(addr, 1);

        /* ra (if not 0) and rb are never modified */

        if (likely(reg != rb && (ra == 0 || reg != ra))) {

            env->gpr[reg] = (env->gpr[reg] & ~(0xFF << d)) | (c << d);

        }

        if (unlikely(c == xer_cmp))

            break;

        if (likely(d != 0)) {

            d -= 8;

        } else {

            d = 24;

            reg++;

            reg = reg & 0x1F;

        }

    }

    return i;

}

/*****************************************************************************/

/* Fixed point operations helpers */

#if defined(TARGET_PPC64)

/* multiply high word */

uint64_t helper_mulhd (uint64_t arg1, uint64_t arg2)

{

    uint64_t tl, th;

    muls64(&tl, &th, arg1, arg2);

    return th;

}

/* multiply high word unsigned */

uint64_t helper_mulhdu (uint64_t arg1, uint64_t arg2)

{

    uint64_t tl, th;

    mulu64(&tl, &th, arg1, arg2);

    return th;

}

uint64_t helper_mulldo (uint64_t arg1, uint64_t arg2)

{

    int64_t th;

    uint64_t tl;

    muls64(&tl, (uint64_t *)&th, arg1, arg2);

    /* If th != 0 && th != -1, then we had an overflow */

    if (likely((uint64_t)(th + 1) <= 1)) {

        env->xer &= ~(1 << XER_OV);

    } else {

        env->xer |= (1 << XER_OV) | (1 << XER_SO);

    }

    return (int64_t)tl;

}

#endif

target_ulong helper_cntlzw (target_ulong t)

{

    return clz32(t);

}

#if defined(TARGET_PPC64)

target_ulong helper_cntlzd (target_ulong t)

{

    return clz64(t);

}

#endif

/* shift right arithmetic helper */

target_ulong helper_sraw (target_ulong value, target_ulong shift)

{

    int32_t ret;

    if (likely(!(shift & 0x20))) {

        if (likely((uint32_t)shift != 0)) {

            shift &= 0x1f;

            ret = (int32_t)value >> shift;

            if (likely(ret >= 0 || (value & ((1 << shift) - 1)) == 0)) {

                env->xer &= ~(1 << XER_CA);

            } else {

                env->xer |= (1 << XER_CA);

            }

        } else {

            ret = (int32_t)value;

            env->xer &= ~(1 << XER_CA);

        }

    } else {

        ret = (int32_t)value >> 31;

        if (ret) {

            env->xer |= (1 << XER_CA);

        } else {

            env->xer &= ~(1 << XER_CA);

        }

    }

    return (target_long)ret;

}

#if defined(TARGET_PPC64)

target_ulong helper_srad (target_ulong value, target_ulong shift)

{

    int64_t ret;

    if (likely(!(shift & 0x40))) {

        if (likely((uint64_t)shift != 0)) {

            shift &= 0x3f;

            ret = (int64_t)value >> shift;

            if (likely(ret >= 0 || (value & ((1 << shift) - 1)) == 0)) {

                env->xer &= ~(1 << XER_CA);

            } else {

                env->xer |= (1 << XER_CA);

            }

        } else {

            ret = (int64_t)value;

            env->xer &= ~(1 << XER_CA);

        }

    } else {

        ret = (int64_t)value >> 63;

        if (ret) {

            env->xer |= (1 << XER_CA);

        } else {

            env->xer &= ~(1 << XER_CA);

        }

    }

    return ret;

}

#endif

#if defined(TARGET_PPC64)

target_ulong helper_popcntb (target_ulong val)

{

    val = (val & 0x5555555555555555ULL) + ((val >>  1) &

                                           0x5555555555555555ULL);

    val = (val & 0x3333333333333333ULL) + ((val >>  2) &

                                           0x3333333333333333ULL);

    val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) &

                                           0x0f0f0f0f0f0f0f0fULL);

    return val;

}

target_ulong helper_popcntw (target_ulong val)

{

    val = (val & 0x5555555555555555ULL) + ((val >>  1) &

                                           0x5555555555555555ULL);

    val = (val & 0x3333333333333333ULL) + ((val >>  2) &

                                           0x3333333333333333ULL);

    val = (val & 0x0f0f0f0f0f0f0f0fULL) + ((val >>  4) &

                                           0x0f0f0f0f0f0f0f0fULL);

    val = (val & 0x00ff00ff00ff00ffULL) + ((val >>  8) &

                                           0x00ff00ff00ff00ffULL);

    val = (val & 0x0000ffff0000ffffULL) + ((val >> 16) &

                                           0x0000ffff0000ffffULL);

    return val;

}

target_ulong helper_popcntd (target_ulong val)

{

    return ctpop64(val);

}

#else

target_ulong helper_popcntb (target_ulong val)

{

    val = (val & 0x55555555) + ((val >>  1) & 0x55555555);

    val = (val & 0x33333333) + ((val >>  2) & 0x33333333);

    val = (val & 0x0f0f0f0f) + ((val >>  4) & 0x0f0f0f0f);

    return val;

}

target_ulong helper_popcntw (target_ulong val)

{

    val = (val & 0x55555555) + ((val >>  1) & 0x55555555);

    val = (val & 0x33333333) + ((val >>  2) & 0x33333333);

    val = (val & 0x0f0f0f0f) + ((val >>  4) & 0x0f0f0f0f);

    val = (val & 0x00ff00ff) + ((val >>  8) & 0x00ff00ff);

    val = (val & 0x0000ffff) + ((val >> 16) & 0x0000ffff);

    return val;

}

#endif

/*****************************************************************************/

/* Floating point operations helpers */

uint64_t helper_float32_to_float64(uint32_t arg)

{

    CPU_FloatU f;

    CPU_DoubleU d;

    f.l = arg;

    d.d = float32_to_float64(f.f, &env->fp_status);

    return d.ll;

}

uint32_t helper_float64_to_float32(uint64_t arg)

{

    CPU_FloatU f;

    CPU_DoubleU d;

    d.ll = arg;

    f.f = float64_to_float32(d.d, &env->fp_status);

    return f.l;

}

static inline int isden(float64 d)

{

    CPU_DoubleU u;

    u.d = d;

    return ((u.ll >> 52) & 0x7FF) == 0;

}

uint32_t helper_compute_fprf (uint64_t arg, uint32_t set_fprf)

{

    CPU_DoubleU farg;

    int isneg;

    int ret;

    farg.ll = arg;

    isneg = float64_is_neg(farg.d);

    if (unlikely(float64_is_any_nan(farg.d))) {

        if (float64_is_signaling_nan(farg.d)) {

            /* Signaling NaN: flags are undefined */

            ret = 0x00;

        } else {

            /* Quiet NaN */

            ret = 0x11;

        }

    } else if (unlikely(float64_is_infinity(farg.d))) {

        /* +/- infinity */

        if (isneg)

            ret = 0x09;

        else

            ret = 0x05;

    } else {

        if (float64_is_zero(farg.d)) {

            /* +/- zero */

            if (isneg)

                ret = 0x12;

            else

                ret = 0x02;

        } else {

            if (isden(farg.d)) {

                /* Denormalized numbers */

                ret = 0x10;

            } else {

                /* Normalized numbers */

                ret = 0x00;

            }

            if (isneg) {

                ret |= 0x08;

            } else {

                ret |= 0x04;

            }

        }

    }

    if (set_fprf) {

        /* We update FPSCR_FPRF */

        env->fpscr &= ~(0x1F << FPSCR_FPRF);

        env->fpscr |= ret << FPSCR_FPRF;

    }

    /* We just need fpcc to update Rc1 */

    return ret & 0xF;

}

/* Floating-point invalid operations exception */

static inline uint64_t fload_invalid_op_excp(int op)

{

    uint64_t ret = 0;

    int ve;

    ve = fpscr_ve;

    switch (op) {

    case POWERPC_EXCP_FP_VXSNAN:

        env->fpscr |= 1 << FPSCR_VXSNAN;

        break;

    case POWERPC_EXCP_FP_VXSOFT:

        env->fpscr |= 1 << FPSCR_VXSOFT;

        break;

    case POWERPC_EXCP_FP_VXISI:

        /* Magnitude subtraction of infinities */

        env->fpscr |= 1 << FPSCR_VXISI;

        goto update_arith;

    case POWERPC_EXCP_FP_VXIDI:

        /* Division of infinity by infinity */

        env->fpscr |= 1 << FPSCR_VXIDI;

        goto update_arith;

    case POWERPC_EXCP_FP_VXZDZ:

        /* Division of zero by zero */

        env->fpscr |= 1 << FPSCR_VXZDZ;

        goto update_arith;

    case POWERPC_EXCP_FP_VXIMZ:

        /* Multiplication of zero by infinity */

        env->fpscr |= 1 << FPSCR_VXIMZ;

        goto update_arith;

    case POWERPC_EXCP_FP_VXVC:

        /* Ordered comparison of NaN */

        env->fpscr |= 1 << FPSCR_VXVC;

        env->fpscr &= ~(0xF << FPSCR_FPCC);

        env->fpscr |= 0x11 << FPSCR_FPCC;

        /* We must update the target FPR before raising the exception */

        if (ve != 0) {

            env->exception_index = POWERPC_EXCP_PROGRAM;

            env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_VXVC;

            /* Update the floating-point enabled exception summary */

            env->fpscr |= 1 << FPSCR_FEX;

            /* Exception is differed */

            ve = 0;

        }

        break;

    case POWERPC_EXCP_FP_VXSQRT:

        /* Square root of a negative number */

        env->fpscr |= 1 << FPSCR_VXSQRT;

    update_arith:

        env->fpscr &= ~((1 << FPSCR_FR) | (1 << FPSCR_FI));

        if (ve == 0) {

            /* Set the result to quiet NaN */

            ret = 0x7FF8000000000000ULL;

            env->fpscr &= ~(0xF << FPSCR_FPCC);

            env->fpscr |= 0x11 << FPSCR_FPCC;

        }

        break;

    case POWERPC_EXCP_FP_VXCVI:

        /* Invalid conversion */

        env->fpscr |= 1 << FPSCR_VXCVI;

        env->fpscr &= ~((1 << FPSCR_FR) | (1 << FPSCR_FI));

        if (ve == 0) {

            /* Set the result to quiet NaN */

            ret = 0x7FF8000000000000ULL;

            env->fpscr &= ~(0xF << FPSCR_FPCC);

            env->fpscr |= 0x11 << FPSCR_FPCC;

        }

        break;

    }

    /* Update the floating-point invalid operation summary */

    env->fpscr |= 1 << FPSCR_VX;

    /* Update the floating-point exception summary */

    env->fpscr |= 1 << FPSCR_FX;

    if (ve != 0) {

        /* Update the floating-point enabled exception summary */

        env->fpscr |= 1 << FPSCR_FEX;

        if (msr_fe0 != 0 || msr_fe1 != 0)

            helper_raise_exception_err(POWERPC_EXCP_PROGRAM, POWERPC_EXCP_FP | op);

    }

    return ret;

}

static inline void float_zero_divide_excp(void)

{

    env->fpscr |= 1 << FPSCR_ZX;

    env->fpscr &= ~((1 << FPSCR_FR) | (1 << FPSCR_FI));

    /* Update the floating-point exception summary */

    env->fpscr |= 1 << FPSCR_FX;

    if (fpscr_ze != 0) {

        /* Update the floating-point enabled exception summary */

        env->fpscr |= 1 << FPSCR_FEX;

        if (msr_fe0 != 0 || msr_fe1 != 0) {

            helper_raise_exception_err(POWERPC_EXCP_PROGRAM,

                                       POWERPC_EXCP_FP | POWERPC_EXCP_FP_ZX);

        }

    }

}

static inline void float_overflow_excp(void)

{

    env->fpscr |= 1 << FPSCR_OX;

    /* Update the floating-point exception summary */

    env->fpscr |= 1 << FPSCR_FX;

    if (fpscr_oe != 0) {

        /* XXX: should adjust the result */

        /* Update the floating-point enabled exception summary */

        env->fpscr |= 1 << FPSCR_FEX;

        /* We must update the target FPR before raising the exception */

        env->exception_index = POWERPC_EXCP_PROGRAM;

        env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_OX;

    } else {

        env->fpscr |= 1 << FPSCR_XX;

        env->fpscr |= 1 << FPSCR_FI;

    }

}

static inline void float_underflow_excp(void)

{

    env->fpscr |= 1 << FPSCR_UX;

    /* Update the floating-point exception summary */

    env->fpscr |= 1 << FPSCR_FX;

    if (fpscr_ue != 0) {

        /* XXX: should adjust the result */

        /* Update the floating-point enabled exception summary */

        env->fpscr |= 1 << FPSCR_FEX;

        /* We must update the target FPR before raising the exception */

        env->exception_index = POWERPC_EXCP_PROGRAM;

        env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_UX;

    }

}

static inline void float_inexact_excp(void)

{

    env->fpscr |= 1 << FPSCR_XX;

    /* Update the floating-point exception summary */

    env->fpscr |= 1 << FPSCR_FX;

    if (fpscr_xe != 0) {

        /* Update the floating-point enabled exception summary */

        env->fpscr |= 1 << FPSCR_FEX;

        /* We must update the target FPR before raising the exception */

        env->exception_index = POWERPC_EXCP_PROGRAM;

        env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_XX;

    }

}

static inline void fpscr_set_rounding_mode(void)

{

    int rnd_type;

    /* Set rounding mode */

    switch (fpscr_rn) {

    case 0:

        /* Best approximation (round to nearest) */

        rnd_type = float_round_nearest_even;

        break;

    case 1:

        /* Smaller magnitude (round toward zero) */

        rnd_type = float_round_to_zero;

        break;

    case 2:

        /* Round toward +infinite */

        rnd_type = float_round_up;

        break;

    default:

    case 3:

        /* Round toward -infinite */

        rnd_type = float_round_down;

        break;

    }

    set_float_rounding_mode(rnd_type, &env->fp_status);

}

void helper_fpscr_clrbit (uint32_t bit)

{

    int prev;

    prev = (env->fpscr >> bit) & 1;

    env->fpscr &= ~(1 << bit);

    if (prev == 1) {

        switch (bit) {

        case FPSCR_RN1:

        case FPSCR_RN:

            fpscr_set_rounding_mode();

            break;

        default:

            break;

        }

    }

}

void helper_fpscr_setbit (uint32_t bit)

{

    int prev;

    prev = (env->fpscr >> bit) & 1;

    env->fpscr |= 1 << bit;

    if (prev == 0) {

        switch (bit) {

        case FPSCR_VX:

            env->fpscr |= 1 << FPSCR_FX;

            if (fpscr_ve)

                goto raise_ve;

        case FPSCR_OX:

            env->fpscr |= 1 << FPSCR_FX;

            if (fpscr_oe)

                goto raise_oe;

            break;

        case FPSCR_UX:

            env->fpscr |= 1 << FPSCR_FX;

            if (fpscr_ue)

                goto raise_ue;

            break;

        case FPSCR_ZX:

            env->fpscr |= 1 << FPSCR_FX;

            if (fpscr_ze)

                goto raise_ze;

            break;

        case FPSCR_XX:

            env->fpscr |= 1 << FPSCR_FX;

            if (fpscr_xe)

                goto raise_xe;

            break;

        case FPSCR_VXSNAN:

        case FPSCR_VXISI:

        case FPSCR_VXIDI:

        case FPSCR_VXZDZ:

        case FPSCR_VXIMZ:

        case FPSCR_VXVC:

        case FPSCR_VXSOFT:

        case FPSCR_VXSQRT:

        case FPSCR_VXCVI:

            env->fpscr |= 1 << FPSCR_VX;

            env->fpscr |= 1 << FPSCR_FX;

            if (fpscr_ve != 0)

                goto raise_ve;

            break;

        case FPSCR_VE:

            if (fpscr_vx != 0) {

            raise_ve:

                env->error_code = POWERPC_EXCP_FP;

                if (fpscr_vxsnan)

                    env->error_code |= POWERPC_EXCP_FP_VXSNAN;

                if (fpscr_vxisi)

                    env->error_code |= POWERPC_EXCP_FP_VXISI;

                if (fpscr_vxidi)

                    env->error_code |= POWERPC_EXCP_FP_VXIDI;

                if (fpscr_vxzdz)

                    env->error_code |= POWERPC_EXCP_FP_VXZDZ;

                if (fpscr_vximz)

                    env->error_code |= POWERPC_EXCP_FP_VXIMZ;

                if (fpscr_vxvc)

                    env->error_code |= POWERPC_EXCP_FP_VXVC;

                if (fpscr_vxsoft)

                    env->error_code |= POWERPC_EXCP_FP_VXSOFT;

                if (fpscr_vxsqrt)

                    env->error_code |= POWERPC_EXCP_FP_VXSQRT;

                if (fpscr_vxcvi)

                    env->error_code |= POWERPC_EXCP_FP_VXCVI;

                goto raise_excp;

            }

            break;

        case FPSCR_OE:

            if (fpscr_ox != 0) {

            raise_oe:

                env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_OX;

                goto raise_excp;

            }

            break;

        case FPSCR_UE:

            if (fpscr_ux != 0) {

            raise_ue:

                env->error_code = POWERPC_EXCP_FP | POWERPC_EXCP_FP_UX;

                goto raise_excp;

            }

            break;

        case FPSCR_ZE: