std::numeric_limits::tinyness_before
De cppreference.com
 |
Esta página se ha traducido por ordenador/computador/computadora de la versión en inglés de la Wiki usando Google Translate.
La traducción puede contener errores y palabras aparatosas/incorrectas. Planea sobre el texto para ver la versión original. Puedes ayudar a corregir los errores y mejorar la traducción. Para instrucciones haz clic aquí. |
static const bool tinyness_before |
(hasta C++11) | |
static constexpr bool tinyness_before |
(desde C++11) | |
El valor de
std::numeric_limits<T>::has_denorm_loss es true para todos los tipos de punto flotante T que los resultados de pruebas de punto flotante expresiones de desbordamiento antes de redondeo .Original:
The value of
std::numeric_limits<T>::has_denorm_loss is true for all floating-point types T that test results of floating-point expressions for underflow before rounding.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Especializaciones estándar
T
|
valor de
std::numeric_limits<T>::tinyness_before Original: value of std::numeric_limits<T>::tinyness_before The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
| /* non-specialized */ | false
|
bool
|
false
|
char
|
false
|
signed char
|
false
|
unsigned char
|
false
|
wchar_t
|
false
|
char16_t
|
false
|
char32_t
|
false
|
short
|
false
|
unsigned short
|
false
|
int
|
false
|
unsigned int
|
false
|
long
|
false
|
unsigned long
|
false
|
long long
|
false
|
unsigned long long
|
false
|
float
|
definido por la implantación
Original: implementation-defined The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
double
|
definido por la implantación
Original: implementation-defined The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
long double
|
definido por la implantación
Original: implementation-defined The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
Notas
Compatible con el estándar IEEE 754 de punto flotante implementaciones pueden detectar el desbordamiento de coma flotante en tres momentos predefinidos:
Original:
Standard-compliant IEEE 754 floating-point implementations may detect the floating-point underflow at three predefined moments:
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
1)
después del cálculo de un resultado con valor absoluto menor que
std::numeric_limits<T>::min(), dicho ejercicio detecta tinyness antes del redondeo (por ejemplo, UltraSparc)Original:
after computation of a result with absolute value smaller than
std::numeric_limits<T>::min(), such implementation detects tinyness before rounding (e.g. UltraSparc)The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
2)
después de redondear el resultado a los bits
std::numeric_limits<T>::digits, si el resultado es muy pequeño, tal aplicación detecta tinyness después de redondear (por ejemplo SuperSPARC)Original:
after rounding of the result to
std::numeric_limits<T>::digits bits, if the result is tiny, such implementation detects tinyness after rounding (e.g. SuperSparc)The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
3)
si la conversión del resultado redondeado se formen pequeñas subnormal resultó en la pérdida de precisión, dicha aplicación detecta la pérdida de denorm .
Original:
if the conversion of the rounded tiny result to subnormal form resulted in the loss of precision, such implementation detects denorm loss.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Ejemplo
Multiplicación del mayor número subnormal por el número epsilon una máquina superior a 1,0 indica el valor minúsculo 0x0.fffffffffffff8p-1022 antes de redondear, pero el valor normal 1p-1022 después de redondear .
Original:
Multiplication of the largest subnormal number by the number one machine epsilon greater than 1.0 gives the tiny value 0x0.fffffffffffff8p-1022 before rounding, but normal value 1p-1022 after rounding.
The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Ejecuta este código
#include <iostream>
#include <limits>
#include <cmath>
#include <cfenv>
int main()
{
double denorm_max = std::nextafter(std::numeric_limits<double>::min(), 0);
double multiplier = 1 + std::numeric_limits<double>::epsilon();
std::feclearexcept(FE_ALL_EXCEPT);
double result = denorm_max*multiplier; // Underflow only if tinyness_before
if(std::fetestexcept(FE_UNDERFLOW))
std::cout << "Underflow detected\n";
else if (std::fetestexcept(FE_INEXACT))
std::cout << "Inexact result detected\n";
std::cout << std::hexfloat << denorm_max << " x " << multiplier << " = "
<< result << '\n';
}
Salida:
Inexact result detected
0x0.fffffffffffffp-1022 x 0x1.0000000000001p+0 = 0x1p-1022
Ver también
[estático] |
identifies the floating-point types that detect loss of precision as denormalization loss rather than inexact result (constante miembro pública estática) |
[estático] |
identifica el estilo desnormalización utilizado por el tipo de punto flotante Original: identifies the denormalization style used by the floating-point type The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (constante miembro pública estática) |