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Re: Cygwin 64bit triplet


On Feb 20 21:14, Yaakov wrote:
> The bootstrap toolchain provided so far has used the x86_64-pc-cygwin
> triplet.  The problem is, now that we've managed to get far enough
> (before I threw a wrench into everything today :-)

Btw!

Even with this change to the size of sszie_t, we have a *very* good
chance that our installations still work.  The reason is a curious
behaviour of the x86_64 CPU when using 32 bit register writes:

Every time, a 32 bit value is transfered into a register, the upper 32
bit are zeroed out:

   before: rax == 0x123456789abcdef

   movl #0x42, %eax

   after:  rax == 0x42

Consider that the first four arguments to a function are always stored
in registers ($rcx, $rdx, $r8, $r9), and consider that return values up
to 64 bit are returned in $rax.

==> There's a good chance we don't see a big difference.

I, just tested to run the "old" tcsh in mintty with the "new" Cygwin
DLL and everything still appears to work.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat


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