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

[jakub at gcc dot gnu.org]

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

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-01-02 
19:01:58 UTC ---
And upper 32 bits are undefined if the argument is 8/16/32 bit (i.e. callee
must sign/zero extend, instead of caller)?