Sollya User's Manual

Names:

halfprecision, HP rounding to the nearest IEEE 754 half-precision number (binary16).

Library names:

sollya_obj_t sollya_lib_halfprecision(sollya_obj_t) sollya_obj_t sollya_lib_halfprecision_obj() int sollya_lib_is_halfprecision_obj(sollya_obj_t) sollya_obj_t sollya_lib_build_function_halfprecision(sollya_obj_t) #define SOLLYA_HP(x) sollya_lib_build_function_halfprecision(x)

Description:

halfprecision is both a function and a constant.
As a function, it rounds its argument to the nearest IEEE 754 half-precision (i.e. IEEE754-2008 binary16) number. Subnormal numbers are supported as well as standard numbers: it is the real rounding described in the standard.
As a constant, it symbolizes the half-precision format. It is used in contexts when a precision format is necessary, e.g. in the commands round and roundcoefficients. It is not supported for implementpoly. See the corresponding help pages for examples.

Example 1:

   > display=binary!;
   > HP(0.1);
   1.100110011_2 * 2^(-4)
   > HP(4.17);
   1.00001011_2 * 2^(2)
   > HP(1.011_2 * 2^(-23));
   1.1_2 * 2^(-23)