Re: Time to merge scratch/correct-warning-pos into master, perhaps?

[Óscar Fuentes]

Eli Zaretskii <eliz@gnu.org> writes:

>> If you want to know the impact of such a change, the correct method is
>> to measure representative instances of real-world cases.
>
> We already did that.  We now want to understand _why_ the new version
> is slower, and then try making it faster.

Then I suggest to use Valgrind for collecting performance data at the
machine instruction level, on a release build (with debug info, of
course.) Knowledge of Assembler and processor architecture required. And
patience, lots of patience.

Although if the difference is also perceptible in a build with -Od, you
could try this before. Its analysis will be much more approachable than
-O2. Then test hypothesis in -O2.