Provides 16-bit floating point support.
The qfloat16
class provides support for half-precision (16-bit) floating point data. 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.
Note
On x86 and x86-64 that to get hardware accelerated conversions you must compile with F16C or AVX2 enabled, or use qFloatToFloat16()
and qFloatFromFloat16()
which will detect F16C at runtime.
Returns a qfloat16 with the sign of sign
but the rest of its value taken from this qfloat16. Serves as qfloat16’s equivalent of std::copysign().
Implements qFpClassify()
for qfloat16.
Returns true
if this qfloat16
value is finite and in normal form.
See also
qFpClassify()
Converts len
qfloat16 from in
to floats and stores them in out
. Both in
and out
must have len
allocated entries.
This function is faster than converting values one by one, and will do runtime F16C detection on x86 and x86-64 hardware.
Converts len
floats from in
to qfloat16 and stores them in out
. Both in
and out
must have len
allocated entries.
This function is faster than converting values one by one, and will do runtime F16C detection on x86 and x86-64 hardware.
This function overloads qFpClassify(float)
.
Returns the floating-point class of val
.
This function overloads qFuzzyCompare(float, float).
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.
This function overloads qIsFinite(float).
Returns true if the qfloat16
f
is a finite number.
This function overloads qIsInf(float).
Returns true if the qfloat16
f
is equivalent to infinity.
This function overloads qIsNaN(float).
Returns true if the qfloat16
f
is not a number (NaN).
This function overloads qRound(float).
Rounds value
to the nearest integer.
This function overloads qRound64(float).
Rounds value
to the nearest 64-bit integer.
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