X-Git-Url: https://git.ucc.asn.au/?p=ipdf%2Fsam.git;a=blobdiff_plain;f=chapters%2FBackground%2FFloats%2FOperations.tex;fp=chapters%2FBackground%2FFloats%2FOperations.tex;h=befb9e7859d6efb3b7ddc9c0af259888ab8d497f;hp=a527c39d319efd05b06846d3b48fae241c7b21f9;hb=a1ede3cfc3ef650aa0f7d3d06e78c6c6ef4cb0cc;hpb=7fe12ce195f039925222ad98b38018ad31d1b1f2 diff --git a/chapters/Background/Floats/Operations.tex b/chapters/Background/Floats/Operations.tex index a527c39..befb9e7 100644 --- a/chapters/Background/Floats/Operations.tex +++ b/chapters/Background/Floats/Operations.tex @@ -1,10 +1,13 @@ -Real values which cannot be represented exactly in a floating point representation must be rounded to the nearest floating point value. The results of a floating point operation will in general be such values and thus there is a rounding error possible in any floating point operation\cite{HFP}. + +Real values which cannot be represented exactly in a floating point representation must be rounded to the nearest floating point value. The results of a floating point operation will in general be such values and thus there is a rounding error possible in any floating point operation\cite{HFP,ieee754std2008, goldberg1991whatevery}. Referring to Figure \ref{floats.pdf} it can be seen that the largest possible rounding error is half the distance between successive floats; this means that rounding errors increase as the value to be represented increases. For the result of a particular operation, the maximum possible rounding error can be determined and is commonly expressed in ``units in the last place'' (ulp), with 1 ulp equivelant to half the distance between successive floats\cite{goldberg1991whatevery}. + \begin{comment} + Floating point operations can in principle be performed using integer operations, but specialised Floating Point Units (FPUs) are an almost universal component of modern processors\cite{kelley1997acmos}. The improvement of FPUs remains highly active in several areas including: efficiency\cite{seidel2001onthe}; accuracy of operations\cite{dieter2007lowcost}; and even the adaptation of algorithms originally used in software, such as Kahan's Fast2Sum algorithm\cite{kadric2013accurate}.