| Message ID | 20190206091043.10985-1-david@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] softfloat: add float128_is_{normal, denormal} | expand |
On 2/6/19 9:10 AM, David Hildenbrand wrote: > Needed on s390x, to test for the data class of a number. So it will > gain soon a user. > > A number is considered normal if the exponent is neither 0 nor all 1's. > That can be checked by adding 1 to the exponent, and comparing against >> = 2 after dropping an eventual overflow into the sign bit. > While at it, convert the other floatXX_is_normal functions to use a > similar, less error prone calculation, as suggested by Richard H. > > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > include/fpu/softfloat.h | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) Reviewed-by: Richard Henderson <richard.henderson@linaro.org> r~
David Hildenbrand <david@redhat.com> writes: > Needed on s390x, to test for the data class of a number. So it will > gain soon a user. > > A number is considered normal if the exponent is neither 0 nor all 1's. > That can be checked by adding 1 to the exponent, and comparing against >>= 2 after dropping an eventual overflow into the sign bit. > > While at it, convert the other floatXX_is_normal functions to use a > similar, less error prone calculation, as suggested by Richard H. Queued to fpu/next, thanks. -- Alex Bennée
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index 38a5e99cf3..3ff5215b81 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -466,7 +466,7 @@ static inline int float32_is_zero_or_denormal(float32 a) static inline bool float32_is_normal(float32 a) { - return ((float32_val(a) + 0x00800000) & 0x7fffffff) >= 0x01000000; + return (((float32_val(a) >> 23) + 1) & 0xff) >= 2; } static inline bool float32_is_denormal(float32 a) @@ -622,7 +622,7 @@ static inline int float64_is_zero_or_denormal(float64 a) static inline bool float64_is_normal(float64 a) { - return ((float64_val(a) + (1ULL << 52)) & -1ULL >> 1) >= 1ULL << 53; + return (((float64_val(a) >> 52) + 1) & 0x7ff) >= 2; } static inline bool float64_is_denormal(float64 a) @@ -940,6 +940,16 @@ static inline int float128_is_zero_or_denormal(float128 a) return (a.high & 0x7fff000000000000LL) == 0; } +static inline bool float128_is_normal(float128 a) +{ + return (((a.high >> 48) + 1) & 0x7fff) >= 2; +} + +static inline bool float128_is_denormal(float128 a) +{ + return float128_is_zero_or_denormal(a) && !float128_is_zero(a); +} + static inline int float128_is_any_nan(float128 a) { return ((a.high >> 48) & 0x7fff) == 0x7fff &&