Am Montag, dem 18.09.2023 um 14:43 +0300 schrieb Alexander Monakov: > On Mon, 18 Sep 2023, Jakub Jelinek wrote: > > > Perhaps we should add some initial hammer approach for the pragma, like > > if you ever use the pragma to turn it somewhere off, it is turned off > > globally, or ditto per function.
I think the default should be off - at least for code that does not contain the pragma anywhere. > > Might be far easier than trying to > > make it precise that contraction is allowed in this expression and not in > > this subexpression of that etc. Of course, making it precise is the > > ultimate goal. > > When implementing -ffp-contract=standard I looked into implementing the > pragma (in a precise manner) and I didn't get the impression it would be > hard to implement for C. But I was somewhat discouraged by the lack of > front-end maintainers reaction to the patch implementing the =standard, > so I didn't pursue that. > > The hardest part would be popping the pragma state when leaving a block, > which didn't seem difficult (at least for C). It is fairly restricted where it can appear, it essentially operates on the level of compound statements (!= blocks). Martin
