fpu/softfloat: Replace float_class_msnan with parts_silence_nan

With a canonical representation of NaNs, we can silence an SNaN
immediately rather than delay until the final format is known.

Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson
2018-05-17 15:24:19 -07:00
parent f7e598e264
commit 0bcfbcbea5
2 changed files with 33 additions and 30 deletions
+23
View File
@@ -138,6 +138,29 @@ static FloatParts parts_default_nan(float_status *status)
};
}
/*----------------------------------------------------------------------------
| Returns a quiet NaN from a signalling NaN for the deconstructed
| floating-point parts.
*----------------------------------------------------------------------------*/
static FloatParts parts_silence_nan(FloatParts a, float_status *status)
{
#ifdef NO_SIGNALING_NANS
g_assert_not_reached();
#elif defined(TARGET_HPPA)
a.frac &= ~(1ULL << (DECOMPOSED_BINARY_POINT - 1));
a.frac |= 1ULL << (DECOMPOSED_BINARY_POINT - 2);
#else
if (status->snan_bit_is_one) {
return parts_default_nan(status);
} else {
a.frac |= 1ULL << (DECOMPOSED_BINARY_POINT - 1);
}
#endif
a.cls = float_class_qnan;
return a;
}
/*----------------------------------------------------------------------------
| The pattern for a default generated half-precision NaN.
*----------------------------------------------------------------------------*/