Re: An article I alluded to

[Miles Bader <miles at gnu dot org>]

Jeffrey Law <law@redhat.com> writes:
>> As this screws up gcc's optimization big time, I actually wrote a gcc
>> patch at one time that detected such "artifically static" variables and
>> changed them into normal automatic variables (at the time I was
>> comparing EEMBC results for gcc versus Greenhill's compiler -- the
>> latter already dealt with such artifically static variables, though as I
>> recall, it did so in an unsafe manner).
>
> "promoting" statics to autos certainly can be done by the compiler if
> you're willing to do use & escape analysis.  Nontrivial, but possible.

The patch I wrote (if I recall correctly; it's been a long time) waited
until after flow analysis had been done, and changed the variables to
auto if no variable-use reached the beginning of the function (and also,
I guess, their address hadn't been taken).

This didn't work perfectly -- some early optimizations get lost because
of the delayed conversion -- but it was fairly effective at sanitizing
all those quirky EEMBC benchmarks, and it was easy to implement.

-Miles
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