[Bug target/66703] [4.9/5/6] gcc.target/i386/readeflags-1.c aborts on -march=i586 or on -miamcu

[julia.koval at intel dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66703

--- Comment #2 from Yulia Koval <julia.koval at intel dot com> ---
Why zero-extend with and is better than zero-extend with movz? Why it's ok to
clobber the flags?