https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113838

--- Comment #4 from absoler at smail dot nju.edu.cn ---
@(In reply to Jakub Jelinek from comment #1)
> Disabling optimizations and then wondering why optimizations didn't happen
> is too weird.  Don't do that.  Such options are intended for debugging GCC,
> or perhaps working around some compiler or application bug, but performance
> of generated code should be only judged without such options.

The gimple ir has no problem, but `_13` is replaced with g_26[5][3][0] in the
follow-up process, this shouldn't be expected behavior.

We question this option because we found in an older version of gcc (10.2.0),
only the O2 option is needed to produce the same bad code, so we worry about
there's a hidden un-fixed problem and it's re-triggered by this option.

Besides, the bad binary code introduce more load operation than the source code
(without optimization), so we thought it's necessary to check it regardless of
which optimization is disabled.

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