Re: How to byte swap an IEEE Float?

[Marius Amado Alves <amado.alves@netcabo.pt>]

On 28 Jun 2005, at 14:53, Björn wrote:

> I need to read some float values from file that have been written in
> big-endian byte order from a c-program. The simple swapping procedure
> that I have just interchanges the byte order of type IEEE_Float_32 to
> get little-endian. The problem is that for some values (eg. 33.229000)
> it is a "NaN" when doing IEEE_Float_32'Read and I get a constraint
> error (invalid data) from stream_io when the value is read. How do I
> get around this?

Simple. Setup an array of bytes with the same representation of the 
float type (use representation clauses and pragma Pack). Read the array 
of bytes. Swap the bytes. Convert to the float type (use unchecked 
conversion).