Additional Data Types Provided by the
ap_float.hpp Header File
ap_float.hpp
Header FileThe
ap_float.hpp
header file provides some aliases for certain data types that you can use instead of explicitly declaring an
ap_float
data type.
Data Type
| Description
|
|---|---|
ihc::bfloat16 | A 16-bit floating-point number with an 8-bit exponent and a 7-bit mantissa (equivalent to declaring
ihc::ap_float<8, 7> ).
On Intel® Agilex™ devices, dot product operations that involve the
bfloat16 (or
ihc::ap_float<8,7> ) data type are mapped to FP16
digital signaling blocks (DSPs). On other device families, dot product operations are mapped to
adaptive logic modules (ALMs) and fixed-point 18-bit DSPs.
On all device families, all other math functions are mapped to ALMs and fixed-point 18-bit DSPs.
|
ihc::bfloat19 | A 19-bit floating-point number with an 8-bit exponent and a 10-bit mantissa (equivalent to declaring
ihc::ap_float<8,10> ).
On Intel® Agilex™ devices, dot product operations that involve the
bfloat19 (or
ihc::ap_float<8,10> ) data type are mapped to FP19
digital signaling blocks (DSPs). On other device families, dot product operations are mapped to
adaptive logic modules (ALMs) and fixed-point 18-bit DSPs.
On all device families, all other math functions are mapped to ALMs and fixed-point 18-bit DSPs.
|
ihc::FPsingle | A 32-bit floating-point number with an 8-bit exponent, a 23-bit mantissa, and a
"Round to the nearest, tie break to even" rounding mode (equivalent to declaring
ihc::ap_float<8, 23, fp_config::FP_Round::RNE> ).Math operations with FPsingle map to the same hardware as the
native float data type when the native float data type uses
IEEE-754 round nearest ties to even (RNE) mode. For information about controlling
the rounding mode for native floating-point data types, refer to Modify the Rounding Mode of Floating-point Operations (-Xsrounding=<rounding_type>). |
ihc::FPdouble | A 64-bit floating-point number with an 11-bit exponent, a 52-bit mantissa, and a
"Round to the nearest, tie break to even" rounding mode (equivalent to declaring
ihc::ap_float<11, 52, fp_config::FP_Round::RNE> ).When subnormal support is on, math operations with FPdouble map to
the same hardware at the native double data type. For information
about controlling the subnormal settings of FPdouble (and other
ap_float data types), refer to Operations with Explicit Precision Controls. |