Commit c84813b8 authored by Laurent Vivier's avatar Laurent Vivier
Browse files

target/m68k: implement facos 



Using a local m68k floatx80_acos()
[copied from previous:
Written by Andreas Grabher for Previous, NeXT Computer Emulator.]

Signed-off-by: default avatarLaurent Vivier <laurent@vivier.eu>
Message-Id: <20180312202728.23790-8-laurent@vivier.eu>
parent bc20b34e

target/m68k/fpu_helper.c

+5 −0
Original line number Diff line number Diff line
@@ -628,3 +628,8 @@ void HELPER(fasin)(CPUM68KState *env, FPReg *res, FPReg *val) 
{

    res->d = floatx80_asin(val->d, &env->fp_status);

}



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

{

    res->d = floatx80_acos(val->d, &env->fp_status);

}

target/m68k/helper.h

+1 −0
Original line number Diff line number Diff line
@@ -81,6 +81,7 @@ DEF_HELPER_3(fcos, void, env, fp, fp) 
DEF_HELPER_4(fsincos, void, env, fp, fp, fp)

DEF_HELPER_3(fatan, void, env, fp, fp)

DEF_HELPER_3(fasin, void, env, fp, fp)

DEF_HELPER_3(facos, 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

+70 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include "fpu/softfloat-macros.h"

#include "softfloat_fpsp_tables.h"



#define pi_exp      0x4000

#define piby2_exp   0x3FFF

#define pi_sig      LIT64(0xc90fdaa22168c235)
@@ -2232,3 +2233,72 @@ floatx80 floatx80_asin(floatx80 a, float_status *status) 


    return a;

}



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

 | Arc cosine

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



floatx80 floatx80_acos(floatx80 a, float_status *status)

{

    flag aSign;

    int32_t aExp;

    uint64_t aSig;



    int8_t user_rnd_mode, user_rnd_prec;



    int32_t compact;

    floatx80 fp0, fp1, one;



    aSig = extractFloatx80Frac(a);

    aExp = extractFloatx80Exp(a);

    aSign = extractFloatx80Sign(a);



    if (aExp == 0x7FFF && (uint64_t) (aSig << 1)) {

        return propagateFloatx80NaNOneArg(a, status);

    }

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

        float_raise(float_flag_inexact, status);

        return roundAndPackFloatx80(status->floatx80_rounding_precision, 0,

                                    piby2_exp, pi_sig, 0, status);

    }



    compact = floatx80_make_compact(aExp, aSig);



    if (compact >= 0x3FFF8000) { /* |X| >= 1 */

        if (aExp == one_exp && aSig == one_sig) { /* |X| == 1 */

            if (aSign) { /* X == -1 */

                a = packFloatx80(0, pi_exp, pi_sig);

                float_raise(float_flag_inexact, status);

                return floatx80_move(a, status);

            } else { /* X == +1 */

                return packFloatx80(0, 0, 0);

            }

        } else { /* |X| > 1 */

            float_raise(float_flag_invalid, status);

            return floatx80_default_nan(status);

        }

    } /* |X| < 1 */



    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;



    one = packFloatx80(0, one_exp, one_sig);

    fp0 = a;



    fp1 = floatx80_add(one, fp0, status);   /* 1 + X */

    fp0 = floatx80_sub(one, fp0, status);   /* 1 - X */

    fp0 = floatx80_div(fp0, fp1, status);   /* (1-X)/(1+X) */

    fp0 = floatx80_sqrt(fp0, status);       /* SQRT((1-X)/(1+X)) */

    fp0 = floatx80_atan(fp0, status);       /* ATAN(SQRT((1-X)/(1+X))) */



    status->float_rounding_mode = user_rnd_mode;

    status->floatx80_rounding_precision = user_rnd_prec;



    a = floatx80_add(fp0, fp0, status);     /* 2 * ATAN(SQRT((1-X)/(1+X))) */



    float_raise(float_flag_inexact, status);



    return a;

}

target/m68k/softfloat.h

+1 −0
Original line number Diff line number Diff line
@@ -39,4 +39,5 @@ floatx80 floatx80_sin(floatx80 a, float_status *status); 
floatx80 floatx80_cos(floatx80 a, float_status *status);

floatx80 floatx80_atan(floatx80 a, float_status *status);

floatx80 floatx80_asin(floatx80 a, float_status *status);

floatx80 floatx80_acos(floatx80 a, float_status *status);

#endif

target/m68k/translate.c

+3 −0
Original line number Diff line number Diff line
@@ -5105,6 +5105,9 @@ DISAS_INSN(fpu) 
    case 0x5e: /* fdneg */

        gen_helper_fdneg(cpu_env, cpu_dest, cpu_src);

        break;

    case 0x1c: /* facos */

        gen_helper_facos(cpu_env, cpu_dest, cpu_src);

        break;

    case 0x1d: /* fcos */

        gen_helper_fcos(cpu_env, cpu_dest, cpu_src);

        break;