[Bug target/111332] Using GCC7.3.0 and GCC10.3.0 to compile the same test case, assembler file instructions are different and performance fallback is obvious.

[d_vampile at 163 dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111332

--- Comment #5 from d_vampile <d_vampile at 163 dot com> ---
According to the analysis, the following two prs may cause the preceding
problems:
PR1:https://github.com/gcc-mirror/gcc/commit/dd9b529f08c3c6064c37234922d298336d78caf7
PR2:https://github.com/gcc-mirror/gcc/commit/e7bf9583fa2a16e9edd5d5347407ad8acc8f9794

I revert PR1 on gcc10.3.0 and found that the assembly instructions changed to
vmovups and vmovups.

And revert PR2, the order of assembly instructions can be consistent with that
of instructions generated during gcc7.3.0 compilation. However, the effects  of
these two PRs and the potential risks of code rollback are still noclear.