<QFloat16> - 16-bit Floating Point Support
The <QFloat16> header file provides 16-bit floating point support. More...
| Header: | #include <QFloat16> |
| Since: | Qt 5.9 |
This documentation was introduced in Qt 5.9.
Functions
| void | qFloatFromFloat16(float *out, const qfloat16 *in, qsizetype len) |
| void | qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len) |
| bool | qFuzzyCompare(qfloat16 p1, qfloat16 p2) |
| bool | qIsFinite(qfloat16 f) |
| bool | qIsInf(qfloat16 f) |
| bool | qIsNaN(qfloat16 f) |
| qint64 | qRound64(qfloat16 value) |
| int | qRound(qfloat16 value) |
Macros
Detailed Description
This header file provides support for half-precision (16-bit) floating point data with the class qfloat16. It is fully compliant with IEEE 754 as a storage type. This implies that any arithmetic operation on a qfloat16 instance results in the value first being converted to a float. This conversion to and from float is performed by hardware when possible, but on processors that do not natively support half-precision, the conversion is performed through a sequence of lookup table operations.
qfloat16 should be treated as if it were a POD (plain old data) type. Consequently, none of the supported operations need any elaboration beyond stating that it supports all arithmetic operators incident to floating point types.
Function Documentation
void qFloatFromFloat16(float *out, const qfloat16 *in, qsizetype len)
Converts len qfloat16 from in to floats and stores them in out. Both in and out must have len allocated entries.
This function was introduced in Qt 5.11.
void qFloatToFloat16(qfloat16 *out, const float *in, qsizetype len)
Converts len floats from in to qfloat16 and stores them in out. Both in and out must have len allocated entries.
This function was introduced in Qt 5.11.
bool qFuzzyCompare(qfloat16 p1, qfloat16 p2)
Compares the floating point value p1 and p2 and returns true if they are considered equal, otherwise false.
The two numbers are compared in a relative way, where the exactness is stronger the smaller the numbers are.
bool qIsFinite(qfloat16 f)
Returns true if the qfloat16 f is a finite number.
See also qIsFinite.
bool qIsInf(qfloat16 f)
Returns true if the qfloat16 f is equivalent to infinity.
See also qIsInf.
bool qIsNaN(qfloat16 f)
Returns true if the qfloat16 f is not a number (NaN).
See also qIsNaN.
qint64 qRound64(qfloat16 value)
Rounds value to the nearest 64-bit integer.
See also qRound64.
int qRound(qfloat16 value)
Rounds value to the nearest integer.
See also qRound.
Macro Documentation
QT_NO_FLOAT16_OPERATORS
Defining this macro disables the arithmetic operators for qfloat16.
This is only necessary on Visual Studio 2017 (and earlier) when including <QFloat16> and <bitset> in the same translation unit, which would otherwise cause a compilation error due to a toolchain bug (see [QTBUG-72073]).
This function was introduced in Qt 5.12.4.
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