diff options
Diffstat (limited to 'Include/pymath.h')
| -rw-r--r-- | Include/pymath.h | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/Include/pymath.h b/Include/pymath.h index 7216a09..6cf69f9 100644 --- a/Include/pymath.h +++ b/Include/pymath.h @@ -187,14 +187,14 @@ PyAPI_FUNC(void) _Py_set_387controlword(unsigned short); * result. * Caution: * This isn't reliable. C99 no longer requires libm to set errno under - * any exceptional condition, but does require +- HUGE_VAL return - * values on overflow. A 754 box *probably* maps HUGE_VAL to a - * double infinity, and we're cool if that's so, unless the input - * was an infinity and an infinity is the expected result. A C89 - * system sets errno to ERANGE, so we check for that too. We're - * out of luck if a C99 754 box doesn't map HUGE_VAL to +Inf, or - * if the returned result is a NaN, or if a C89 box returns HUGE_VAL - * in non-overflow cases. + * any exceptional condition, but does require +- HUGE_VAL return + * values on overflow. A 754 box *probably* maps HUGE_VAL to a + * double infinity, and we're cool if that's so, unless the input + * was an infinity and an infinity is the expected result. A C89 + * system sets errno to ERANGE, so we check for that too. We're + * out of luck if a C99 754 box doesn't map HUGE_VAL to +Inf, or + * if the returned result is a NaN, or if a C89 box returns HUGE_VAL + * in non-overflow cases. * X is evaluated more than once. * Some platforms have better way to spell this, so expect some #ifdef'ery. * @@ -211,8 +211,20 @@ PyAPI_FUNC(void) _Py_set_387controlword(unsigned short); #define Py_OVERFLOWED(X) isinf(X) #else #define Py_OVERFLOWED(X) ((X) != 0.0 && (errno == ERANGE || \ - (X) == Py_HUGE_VAL || \ - (X) == -Py_HUGE_VAL)) -#endif + (X) == Py_HUGE_VAL || \ + (X) == -Py_HUGE_VAL)) +#endif + +/* Return whether integral type *type* is signed or not. */ +#define _Py_IntegralTypeSigned(type) ((type)(-1) < 0) +/* Return the maximum value of integral type *type*. */ +#define _Py_IntegralTypeMax(type) ((_Py_IntegralTypeSigned(type)) ? (((((type)1 << (sizeof(type)*CHAR_BIT - 2)) - 1) << 1) + 1) : ~(type)0) +/* Return the minimum value of integral type *type*. */ +#define _Py_IntegralTypeMin(type) ((_Py_IntegralTypeSigned(type)) ? -_Py_IntegralTypeMax(type) - 1 : 0) +/* Check whether *v* is in the range of integral type *type*. This is most + * useful if *v* is floating-point, since demoting a floating-point *v* to an + * integral type that cannot represent *v*'s integral part is undefined + * behavior. */ +#define _Py_InIntegralTypeRange(type, v) (_Py_IntegralTypeMin(type) <= v && v <= _Py_IntegralTypeMax(type)) #endif /* Py_PYMATH_H */ |