Re: [PATCH] [strub] improve handling of indirected volatile parms [PR112938]

[Alexandre Oliva <oliva@adacore.com>]

On Mar 11, 2024, Richard Biener <richard.guenther@gmail.com> wrote:

> On Sat, Mar 9, 2024 at 10:10 AM Alexandre Oliva <oliva@adacore.com> wrote:
>> 
>> 
>> The earlier patch for PR112938 arranged for volatile parms to be made
>> indirect in internal strub wrapped bodies.
>> 
>> The first problem that remained, more evident, was that the indirected
>> parameter remained volatile, despite the indirection, but it wasn't
>> regimplified, so indirecting it was malformed gimple.
>> 
>> Regimplifying turned out not to be needed.  The best course of action
>> was to drop the volatility from the by-reference parm, that was being
>> unexpectedly inherited from the original volatile parm.
>> 
>> That exposed another problem: the dereferences would then lose their
>> volatile status, so we had to bring volatile back to them.
>> 
>> Regstrapped on x86_64-linux-gnu.  Ok to install?

> OK

Thanks, sorry, I dropped the ball on this one.

I'm going to put it in momentarily.  It had been approved for gcc 14,
before it branched off; should I install it there as well?

>> 
>> for  gcc/ChangeLog
>> 
>> PR middle-end/112938
>> * ipa-strub.cc (pass_ipa_strub::execute): Drop volatility from
>> indirected parm.
>> (maybe_make_indirect): Restore volatility in dereferences.
>> 
>> for  gcc/testsuite/ChangeLog
>> 
>> PR middle-end/112938
>> * g++.dg/strub-internal-pr112938.cc: New.


-- 
Alexandre Oliva, happy hacker            https://FSFLA.org/blogs/lxo/
   Free Software Activist                   GNU Toolchain Engineer
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