[Bug middle-end/115863] [15 Regression] zlib-1.3.1 miscompilation since r15-1936-g80e446e829d818

[pan2.li at intel dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115863

--- Comment #13 from Li Pan <pan2.li at intel dot com> ---
Thanks Richard and Bizjak.

Got the point here, and let me have a try for the improvement.