Commit 068f1615 authored by Laurent Vivier's avatar Laurent Vivier
Browse files

target/m68k: implement ftwotox 



Using a local m68k floatx80_twotox()
[copied from previous:
Written by Andreas Grabher for Previous, NeXT Computer Emulator.]

Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
Message-Id: <20180305203910.10391-8-laurent@vivier.eu>
parent 40ad0873

target/m68k/fpu_helper.c

+5 −0
Original line number Diff line number Diff line
@@ -582,3 +582,8 @@ void HELPER(fetox)(CPUM68KState *env, FPReg *res, FPReg *val) 
{

    res->d = floatx80_etox(val->d, &env->fp_status);

}



void HELPER(ftwotox)(CPUM68KState *env, FPReg *res, FPReg *val)

{

    res->d = floatx80_twotox(val->d, &env->fp_status);

}

target/m68k/helper.h

+1 −0
Original line number Diff line number Diff line
@@ -73,6 +73,7 @@ DEF_HELPER_3(flogn, void, env, fp, fp) 
DEF_HELPER_3(flog10, void, env, fp, fp)

DEF_HELPER_3(flog2, void, env, fp, fp)

DEF_HELPER_3(fetox, void, env, fp, fp)

DEF_HELPER_3(ftwotox, void, env, fp, fp)



DEF_HELPER_3(mac_move, void, env, i32, i32)

DEF_HELPER_3(macmulf, i64, env, i32, i32)

target/m68k/softfloat.c

+148 −0
Original line number Diff line number Diff line
@@ -965,3 +965,151 @@ floatx80 floatx80_etox(floatx80 a, float_status *status) 
        return a;

    }

}



/*----------------------------------------------------------------------------

 | 2 to x

 *----------------------------------------------------------------------------*/



floatx80 floatx80_twotox(floatx80 a, float_status *status)

{

    flag aSign;

    int32_t aExp;

    uint64_t aSig;



    int8_t user_rnd_mode, user_rnd_prec;



    int32_t compact, n, j, l, m, m1;

    floatx80 fp0, fp1, fp2, fp3, adjfact, fact1, fact2;



    aSig = extractFloatx80Frac(a);

    aExp = extractFloatx80Exp(a);

    aSign = extractFloatx80Sign(a);



    if (aExp == 0x7FFF) {

        if ((uint64_t) (aSig << 1)) {

            return propagateFloatx80NaNOneArg(a, status);

        }

        if (aSign) {

            return packFloatx80(0, 0, 0);

        }

        return packFloatx80(0, floatx80_infinity.high,

                            floatx80_infinity.low);

    }



    if (aExp == 0 && aSig == 0) {

        return packFloatx80(0, one_exp, one_sig);

    }



    user_rnd_mode = status->float_rounding_mode;

    user_rnd_prec = status->floatx80_rounding_precision;

    status->float_rounding_mode = float_round_nearest_even;

    status->floatx80_rounding_precision = 80;



    fp0 = a;



    compact = floatx80_make_compact(aExp, aSig);



    if (compact < 0x3FB98000 || compact > 0x400D80C0) {

        /* |X| > 16480 or |X| < 2^(-70) */

        if (compact > 0x3FFF8000) { /* |X| > 16480 */

            status->float_rounding_mode = user_rnd_mode;

            status->floatx80_rounding_precision = user_rnd_prec;



            if (aSign) {

                return roundAndPackFloatx80(status->floatx80_rounding_precision,

                                            0, -0x1000, aSig, 0, status);

            } else {

                return roundAndPackFloatx80(status->floatx80_rounding_precision,

                                            0, 0x8000, aSig, 0, status);

            }

        } else { /* |X| < 2^(-70) */

            status->float_rounding_mode = user_rnd_mode;

            status->floatx80_rounding_precision = user_rnd_prec;



            a = floatx80_add(fp0, float32_to_floatx80(

                             make_float32(0x3F800000), status),

                             status); /* 1 + X */



            float_raise(float_flag_inexact, status);



            return a;

        }

    } else { /* 2^(-70) <= |X| <= 16480 */

        fp1 = fp0; /* X */

        fp1 = floatx80_mul(fp1, float32_to_floatx80(

                           make_float32(0x42800000), status),

                           status); /* X * 64 */

        n = floatx80_to_int32(fp1, status);

        fp1 = int32_to_floatx80(n, status);

        j = n & 0x3F;

        l = n / 64; /* NOTE: this is really arithmetic right shift by 6 */

        if (n < 0 && j) {

            /* arithmetic right shift is division and

             * round towards minus infinity

             */

            l--;

        }

        m = l / 2; /* NOTE: this is really arithmetic right shift by 1 */

        if (l < 0 && (l & 1)) {

            /* arithmetic right shift is division and

             * round towards minus infinity

             */

            m--;

        }

        m1 = l - m;

        m1 += 0x3FFF; /* ADJFACT IS 2^(M') */



        adjfact = packFloatx80(0, m1, one_sig);

        fact1 = exp2_tbl[j];

        fact1.high += m;

        fact2.high = exp2_tbl2[j] >> 16;

        fact2.high += m;

        fact2.low = (uint64_t)(exp2_tbl2[j] & 0xFFFF);

        fact2.low <<= 48;



        fp1 = floatx80_mul(fp1, float32_to_floatx80(

                           make_float32(0x3C800000), status),

                           status); /* (1/64)*N */

        fp0 = floatx80_sub(fp0, fp1, status); /* X - (1/64)*INT(64 X) */

        fp2 = packFloatx80(0, 0x3FFE, LIT64(0xB17217F7D1CF79AC)); /* LOG2 */

        fp0 = floatx80_mul(fp0, fp2, status); /* R */



        /* EXPR */

        fp1 = floatx80_mul(fp0, fp0, status); /* S = R*R */

        fp2 = float64_to_floatx80(make_float64(0x3F56C16D6F7BD0B2),

                                  status); /* A5 */

        fp3 = float64_to_floatx80(make_float64(0x3F811112302C712C),

                                  status); /* A4 */

        fp2 = floatx80_mul(fp2, fp1, status); /* S*A5 */

        fp3 = floatx80_mul(fp3, fp1, status); /* S*A4 */

        fp2 = floatx80_add(fp2, float64_to_floatx80(

                           make_float64(0x3FA5555555554CC1), status),

                           status); /* A3+S*A5 */

        fp3 = floatx80_add(fp3, float64_to_floatx80(

                           make_float64(0x3FC5555555554A54), status),

                           status); /* A2+S*A4 */

        fp2 = floatx80_mul(fp2, fp1, status); /* S*(A3+S*A5) */

        fp3 = floatx80_mul(fp3, fp1, status); /* S*(A2+S*A4) */

        fp2 = floatx80_add(fp2, float64_to_floatx80(

                           make_float64(0x3FE0000000000000), status),

                           status); /* A1+S*(A3+S*A5) */

        fp3 = floatx80_mul(fp3, fp0, status); /* R*S*(A2+S*A4) */



        fp2 = floatx80_mul(fp2, fp1, status); /* S*(A1+S*(A3+S*A5)) */

        fp0 = floatx80_add(fp0, fp3, status); /* R+R*S*(A2+S*A4) */

        fp0 = floatx80_add(fp0, fp2, status); /* EXP(R) - 1 */



        fp0 = floatx80_mul(fp0, fact1, status);

        fp0 = floatx80_add(fp0, fact2, status);

        fp0 = floatx80_add(fp0, fact1, status);



        status->float_rounding_mode = user_rnd_mode;

        status->floatx80_rounding_precision = user_rnd_prec;



        a = floatx80_mul(fp0, adjfact, status);



        float_raise(float_flag_inexact, status);



        return a;

    }

}

target/m68k/softfloat.h

+1 −0
Original line number Diff line number Diff line
@@ -32,4 +32,5 @@ floatx80 floatx80_logn(floatx80 a, float_status *status); 
floatx80 floatx80_log10(floatx80 a, float_status *status);

floatx80 floatx80_log2(floatx80 a, float_status *status);

floatx80 floatx80_etox(floatx80 a, float_status *status);

floatx80 floatx80_twotox(floatx80 a, float_status *status);

#endif

target/m68k/softfloat_fpsp_tables.h

+86 −0
Original line number Diff line number Diff line
@@ -285,4 +285,90 @@ static const float32 exp_tbl2[64] = { 
    const_float32(0xA041ED22),

    const_float32(0x1F853F3A),

};



static const floatx80 exp2_tbl[64] = {

    make_floatx80_init(0x3FFF, 0x8000000000000000),

    make_floatx80_init(0x3FFF, 0x8164D1F3BC030773),

    make_floatx80_init(0x3FFF, 0x82CD8698AC2BA1D7),

    make_floatx80_init(0x3FFF, 0x843A28C3ACDE4046),

    make_floatx80_init(0x3FFF, 0x85AAC367CC487B15),

    make_floatx80_init(0x3FFF, 0x871F61969E8D1010),

    make_floatx80_init(0x3FFF, 0x88980E8092DA8527),

    make_floatx80_init(0x3FFF, 0x8A14D575496EFD9A),

    make_floatx80_init(0x3FFF, 0x8B95C1E3EA8BD6E7),

    make_floatx80_init(0x3FFF, 0x8D1ADF5B7E5BA9E6),

    make_floatx80_init(0x3FFF, 0x8EA4398B45CD53C0),

    make_floatx80_init(0x3FFF, 0x9031DC431466B1DC),

    make_floatx80_init(0x3FFF, 0x91C3D373AB11C336),

    make_floatx80_init(0x3FFF, 0x935A2B2F13E6E92C),

    make_floatx80_init(0x3FFF, 0x94F4EFA8FEF70961),

    make_floatx80_init(0x3FFF, 0x96942D3720185A00),

    make_floatx80_init(0x3FFF, 0x9837F0518DB8A96F),

    make_floatx80_init(0x3FFF, 0x99E0459320B7FA65),

    make_floatx80_init(0x3FFF, 0x9B8D39B9D54E5539),

    make_floatx80_init(0x3FFF, 0x9D3ED9A72CFFB751),

    make_floatx80_init(0x3FFF, 0x9EF5326091A111AE),

    make_floatx80_init(0x3FFF, 0xA0B0510FB9714FC2),

    make_floatx80_init(0x3FFF, 0xA27043030C496819),

    make_floatx80_init(0x3FFF, 0xA43515AE09E6809E),

    make_floatx80_init(0x3FFF, 0xA5FED6A9B15138EA),

    make_floatx80_init(0x3FFF, 0xA7CD93B4E965356A),

    make_floatx80_init(0x3FFF, 0xA9A15AB4EA7C0EF8),

    make_floatx80_init(0x3FFF, 0xAB7A39B5A93ED337),

    make_floatx80_init(0x3FFF, 0xAD583EEA42A14AC6),

    make_floatx80_init(0x3FFF, 0xAF3B78AD690A4375),

    make_floatx80_init(0x3FFF, 0xB123F581D2AC2590),

    make_floatx80_init(0x3FFF, 0xB311C412A9112489),

    make_floatx80_init(0x3FFF, 0xB504F333F9DE6484),

    make_floatx80_init(0x3FFF, 0xB6FD91E328D17791),

    make_floatx80_init(0x3FFF, 0xB8FBAF4762FB9EE9),

    make_floatx80_init(0x3FFF, 0xBAFF5AB2133E45FB),

    make_floatx80_init(0x3FFF, 0xBD08A39F580C36BF),

    make_floatx80_init(0x3FFF, 0xBF1799B67A731083),

    make_floatx80_init(0x3FFF, 0xC12C4CCA66709456),

    make_floatx80_init(0x3FFF, 0xC346CCDA24976407),

    make_floatx80_init(0x3FFF, 0xC5672A115506DADD),

    make_floatx80_init(0x3FFF, 0xC78D74C8ABB9B15D),

    make_floatx80_init(0x3FFF, 0xC9B9BD866E2F27A3),

    make_floatx80_init(0x3FFF, 0xCBEC14FEF2727C5D),

    make_floatx80_init(0x3FFF, 0xCE248C151F8480E4),

    make_floatx80_init(0x3FFF, 0xD06333DAEF2B2595),

    make_floatx80_init(0x3FFF, 0xD2A81D91F12AE45A),

    make_floatx80_init(0x3FFF, 0xD4F35AABCFEDFA1F),

    make_floatx80_init(0x3FFF, 0xD744FCCAD69D6AF4),

    make_floatx80_init(0x3FFF, 0xD99D15C278AFD7B6),

    make_floatx80_init(0x3FFF, 0xDBFBB797DAF23755),

    make_floatx80_init(0x3FFF, 0xDE60F4825E0E9124),

    make_floatx80_init(0x3FFF, 0xE0CCDEEC2A94E111),

    make_floatx80_init(0x3FFF, 0xE33F8972BE8A5A51),

    make_floatx80_init(0x3FFF, 0xE5B906E77C8348A8),

    make_floatx80_init(0x3FFF, 0xE8396A503C4BDC68),

    make_floatx80_init(0x3FFF, 0xEAC0C6E7DD24392F),

    make_floatx80_init(0x3FFF, 0xED4F301ED9942B84),

    make_floatx80_init(0x3FFF, 0xEFE4B99BDCDAF5CB),

    make_floatx80_init(0x3FFF, 0xF281773C59FFB13A),

    make_floatx80_init(0x3FFF, 0xF5257D152486CC2C),

    make_floatx80_init(0x3FFF, 0xF7D0DF730AD13BB9),

    make_floatx80_init(0x3FFF, 0xFA83B2DB722A033A),

    make_floatx80_init(0x3FFF, 0xFD3E0C0CF486C175)

};



static const uint32_t exp2_tbl2[64] = {

    0x3F738000, 0x3FBEF7CA, 0x3FBDF8A9, 0x3FBCD7C9,

    0xBFBDE8DA, 0x3FBDE85C, 0x3FBEBBF1, 0x3FBB80CA,

    0xBFBA8373, 0xBFBE9670, 0x3FBDB700, 0x3FBEEEB0,

    0x3FBBFD6D, 0xBFBDB319, 0x3FBDBA2B, 0x3FBE91D5,

    0x3FBE8D5A, 0xBFBCDE7B, 0xBFBEBAAF, 0xBFBD86DA,

    0xBFBEBEDD, 0x3FBCC96E, 0xBFBEC90B, 0x3FBBD1DB,

    0x3FBCE5EB, 0xBFBEC274, 0x3FBEA83C, 0x3FBECB00,

    0x3FBE9301, 0xBFBD8367, 0xBFBEF05F, 0x3FBDFB3C,

    0x3FBEB2FB, 0x3FBAE2CB, 0x3FBCDC3C, 0x3FBEE9AA,

    0xBFBEAEFD, 0xBFBCBF51, 0x3FBEF88A, 0x3FBD83B2,

    0x3FBDF8AB, 0xBFBDFB17, 0xBFBEFE3C, 0xBFBBB6F8,

    0xBFBCEE53, 0xBFBDA4AE, 0x3FBC9124, 0x3FBEB243,

    0x3FBDE69A, 0xBFB8BC61, 0x3FBDF610, 0xBFBD8BE1,

    0x3FBACB12, 0x3FBB9BFE, 0x3FBCF2F4, 0x3FBEF22F,

    0xBFBDBF4A, 0x3FBEC01A, 0x3FBE8CAC, 0xBFBCBB3F,

    0x3FBEF73A, 0xBFB8B795, 0x3FBEF84B, 0xBFBEF581

};

#endif