target/m68k: implement fatanh

Using a local m68k floatx80_atanh()
[copied from previous:
Written by Andreas Grabher for Previous, NeXT Computer Emulator.]

Backports commit e3655afa137b2e0999537eef273a2845ba21d68c from qemu
This commit is contained in:
Laurent Vivier 2018-03-15 16:22:29 -04:00 committed by Lioncash
parent f116fd15c9
commit 2740114ed6
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5 changed files with 75 additions and 0 deletions

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@ -644,3 +644,8 @@ void HELPER(facos)(CPUM68KState *env, FPReg *res, FPReg *val)
{
res->d = floatx80_acos(val->d, &env->fp_status);
}
void HELPER(fatanh)(CPUM68KState *env, FPReg *res, FPReg *val)
{
res->d = floatx80_atanh(val->d, &env->fp_status);
}

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@ -84,6 +84,7 @@ 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(fatanh, void, env, fp, fp)
DEF_HELPER_3(mac_move, void, env, i32, i32)
DEF_HELPER_3(macmulf, i64, env, i32, i32)

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@ -2302,3 +2302,68 @@ floatx80 floatx80_acos(floatx80 a, float_status *status)
return a;
}
/*----------------------------------------------------------------------------
| Hyperbolic arc tangent
*----------------------------------------------------------------------------*/
floatx80 floatx80_atanh(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, fp2, 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) {
return packFloatx80(aSign, 0, 0);
}
compact = floatx80_make_compact(aExp, aSig);
if (compact >= 0x3FFF8000) { /* |X| >= 1 */
if (aExp == one_exp && aSig == one_sig) { /* |X| == 1 */
float_raise(float_flag_divbyzero, status);
return packFloatx80(aSign, floatx80_infinity.high,
floatx80_infinity.low);
} 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);
fp2 = packFloatx80(aSign, 0x3FFE, one_sig); /* SIGN(X) * (1/2) */
fp0 = packFloatx80(0, aExp, aSig); /* Y = |X| */
fp1 = packFloatx80(1, aExp, aSig); /* -Y */
fp0 = floatx80_add(fp0, fp0, status); /* 2Y */
fp1 = floatx80_add(fp1, one, status); /* 1-Y */
fp0 = floatx80_div(fp0, fp1, status); /* Z = 2Y/(1-Y) */
fp0 = floatx80_lognp1(fp0, status); /* LOG1P(Z) */
status->float_rounding_mode = user_rnd_mode;
status->floatx80_rounding_precision = user_rnd_prec;
a = floatx80_mul(fp0, fp2,
status); /* ATANH(X) = SIGN(X) * (1/2) * LOG1P(Z) */
float_raise(float_flag_inexact, status);
return a;
}

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@ -40,4 +40,5 @@ 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);
floatx80 floatx80_atanh(floatx80 a, float_status *status);
#endif

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@ -5297,6 +5297,9 @@ DISAS_INSN(fpu)
case 0x0c: /* fasin */
gen_helper_fasin(tcg_ctx, uc->cpu_env, cpu_dest, cpu_src);
break;
case 0x0d: /* fatanh */
gen_helper_fatanh(tcg_ctx, uc->cpu_env, cpu_dest, cpu_src);
break;
case 0x0e: /* fsin */
gen_helper_fsin(tcg_ctx, uc->cpu_env, cpu_dest, cpu_src);
break;