[Bug target/46942] x86_64 parameter passing unnecessary sign/zero extends

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46942

--- Comment #6 from H.J. Lu <hjl.tools at gmail dot com> 2011-01-02 20:53:12 UTC ---
(In reply to comment #5)
> And upper 32 bits are undefined if the argument is 8/16/32 bit (i.e. callee
> must sign/zero extend, instead of caller)?

If callee wants 64bit, it has to sign/zero extend it to 64bit.