Posted by Erland Sommarskog on 10/01/14 11:40

mmt1 (mehrnaz.monajati@gmail.com) writes:
> I have a multiplier that multiplies 2 floating point numbers with 7
> bits exponent and 10 bits mantissa.so its output has 7 bits exponent
> and 20 bits mantissa.
> now its output must return to its input in order to compute another
> multiplication.on the other hand its output must be truncated to 10
> bits. how can I do this? please help me.

This questions appears somewhat strange in the context of SQL Server.
How is your data stored?

In SQL Server there are two data types for floating-point values,
real and float. real values have a 24-bit mantissa and 7-bit exponent
and float have a 53-bit mantissa.

Using these in the manner you ask for. If you have

DECLARE @a real, @b real, @c real
...
SELECT @a * @b * @c

SQL Server first (probably) computes @a * @b which yields a new real
number which then is multiplied with @c.

--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se

Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx

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