PATCH: Move sysdeps/x86_64/Implies to sysdeps/x86_64/64

[Joseph S. Myers]

On Fri, 6 Apr 2012, H.J. Lu wrote:

> For x86-64, with Implies-after, the search order can only be
> 
> ieee754/ldbl-96
> ieee754/dbl-64/wordsize-64
> ieee754/dbl-64
> ieee754/flt-32
> wordsize-64
> 
> not
> 
> wordsize-64
> ieee754/ldbl-96
> ieee754/dbl-64/wordsize-64
> ieee754/dbl-64
> ieee754/flt-32

Thanks for giving a concrete different in orders.  The next question is: 
why does that difference matter for x32?  (If it doesn't, you need to give 
an example of a case where the order *does* matter and you can't get the 
order you want.)

My guess is that "wordsize-64" is being used for more than one thing, and 
should actually be split up; some files may be for "64-bit operations are 
efficient", some for "long and long long are both 64-bit", some for 
"dirent64 is the same as dirent".  If we can distinguish the various ways 
"wordsize-64" is used, then x32 could use a different subset of the new 
directories from pure 64-bit.

(We also need a clear statement of what the __WORDSIZE define from 
bits/wordsize.h means.  Given the uses in stdint.h, and existing practice 
for MIPS for example, I think it's "long is 64-bit".)

-- 
Joseph S. Myers
joseph@codesourcery.com