Host endian independence

[Joseph Myers]

On Sat, 24 Aug 2019, Damien Zammit wrote:

> Please see attached patches for proof of concept, which remove
> dependence on BYTE_ORDER for two subfolders of glibc.

I don't think these changes are appropriate.

I think we should make more use of the *existing* byte-swap interfaces, 
such as be32toh and be64toh in <endian.h>, rather than inventing new ones.  
By using those interfaces, tzfile.c, for example, could lose some of its 
existing endian checks (that would be a very small local change to the 
implementations of the decode and decode64 functions, larger changes are 
not needed and make the code less clean because the logical information 
that certain data is stored in the files in big-endian format is best kept 
local to the implementations of those two functions, rather than 
hardcoding that information in lots of places with read_be32 and read_be64 
names).  (I'm not convinced that any changes in this area beyond very 
minimal use of bswap_32 would improve the catgets code.)

-- 
Joseph S. Myers
joseph@codesourcery.com