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Re: 50% slowdown with LTO
Ian Lance Taylor <firstname.lastname@example.org> writes:
> Figuring out what has gone wrong is like optimizing any program. Get
> a profile for your program, e.g., using -pg. Build the program with
> and without -flto, run it, and look at the resulting profiles. A 50%
> slowdown should be fairly obvious. I would guess that GCC has made a
> poor inlining decision, but the profile should show the problem for
On modern profiling tools like perf or oprofile you can also
"diff" profiles for this.
email@example.com -- Speaking for myself only