Bytes order and words order

[Richard Earnshaw]

> 
> Hi,
> 
>   Supports for floating-point data types in the C++ runtime system
> require me to know the bytes and words orders used by the target.  I
> would like to have means for the front-end or driver to pass those
> information down to the library.  I think a minimal path would be for
> CPP to define some macros like
> 
>     -D__TARGET_BYTES_ORDER__=__BIG_ENDIAN__ (or __LITTLE_ENDIAN__)
>     -D__TARGET_WORDS_ORDER__=__BIG_ENDIAN__ (or __LITTLE_ENDIAN__)
> 
> with, for example, __LITTLE_ENDIAN__ and __BIG_ENDIAN__ predefined to 0
> and 1 respectivelly.  The same set of macros would be needed for the
> host in case of cross-compiling.
> 
> I'll also need symbols for the floating-point model used.
> 
> Thoughts? Neil?

Don't assume that the word-order of a floating-point number will be the 
same as the word-order of an integral type.  It isn't the case on the FPA 
co-processor for the ARM for instance.

R.