[Bug middle-end/82004] [8 Regression] SPEC CPU2017 628.pop2_s miscompare

[mailboxnotfound at yahoo dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82004

--- Comment #47 from john henning <mailboxnotfound at yahoo dot com> ---
SPEC next step: Because the performance differences were small (in my limited
testing) no matter which workaround I picked (-O3, or remove Feedback Directed
Optimization, or add -fno-unsafe-math-optimizations), I will probably update
the CPU 2017 Docs to recommend simply that GCC users set "basepeak" for
628.pop2. This turns off FDO, and is easy for them to do. 
(https://www.spec.org/cpu2017/Docs/config.html#basepeak)

A loose end: is it worth filing a documentation bug for the fact that using the
alleged components of -fno-unsafe-math-optimizations does not have the same
effect as -fno-unsafe-math-optimizations itself?  (See the attachment from
comment 46)