[Bug middle-end/78995] A strange copy error caused by O3 optimization

[zhangfei1 at cffex dot com.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78995

--- Comment #3 from feiz <zhangfei1 at cffex dot com.cn> ---
(In reply to Andrew Pinski from comment #1)
> Does adding -fno-strict-aliasing fix the problem you are seeing?
> 
> I am suspecting the code is violating C/C++ aliasing rules.

Yeah, that's right. I try the -fno-strict-aliasing options, and it works.
Very thanks for your help.