Re: Bytes order and words order

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Richard Earnshaw <rearnsha@arm.com> writes:

| > 
| > 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.

OK, thanks.  I was actually thinking of the word-order of
floating-point numbers not that of integral types.  I think I should
name it  __TARGET_FLOAT_WORDS_ORDER__ ?  
Is it reasonable to assume that the byte order of integral and
floating point coincide? 

-- Gaby