Cygwin 64bit triplet
Corinna Vinschen
corinna-cygwin@cygwin.com
Thu Feb 21 12:40:00 GMT 2013
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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