| 摘要 |
<p>Apparatus for processing data includes processing circuitry 16, 18, 20, 22, 24, 26 and decoder circuitry 14 for decoding program instructions. The program instructions decoded include a floating point pre-conversion instruction, which performs round-to-nearest ties to even rounding upon the mantissa field of an input floating number to generate an output floating point number with the mantissa rounded to a position corresponding to a shorter mantissa field, to which the number is later to be converted, and concatenated with a suffix of zero values to provide the same mantissa length. The decoder is also responsive to an integer pre-conversion instruction, to quantise an input integer value using round-to-nearest ties to even rounding to form an output integer operand with a number of significant bits matched to the mantissa size of a floating point number to which the integer is later to be converted. These instructions ensure that rounding errors are avoided during the later conversion.</p> |
