search for: supported_optimizations

On Mon, Dec 3, 2018 at 11:49 PM John McCall <jmccall at apple.com> wrote: > Piotr's proposal unfortunately doesn't give us a good name for the class > of optimizations that require being listed in supported_optimizations. > In earlier discussions I called them "brittle", but I can understand why > nobody wants to call their optimization that, so let's call them > "good-faith optimizations" instead since they rely on the good faith of > all the participating code. > > Every...

I think we should have some bounds on how "badly" a supported_optimizations tag on a function can affect its semantics. For instance, can a "supported_optimizations" invariant be that "the CFG is always structured"? Or (exaggerating to illustrate the point) "the function has an equal number of loads and stores"? -- Sanjoy On Mon, Dec 3, 2018...

Hi folks, please check out our RFC: Supported Optimizations attribute https://docs.google.com/document/d/1s0n-JVaSNML1Z9SCZVg2bgisxswIJAK2Tp9DahucW10/edit?usp=sharing Pasting it here for the record: RFC: supported_optimizations attribute Piotr Padlewski - piotr.padlewski at gmail.com Krzysztof Pszeniczny - kpszeniczny at google.com December 2018 Introduction Sometimes a possible class of optimizations requires very precise use of metadata and/or intrinsics, at least to achieve a clean implementation thereof. Our prima...

...n Mon, Dec 3, 2018 at 11:49 PM John McCall jmccall at apple.com > <mailto:jmccall at apple.com> wrote: > > Piotr's proposal unfortunately doesn't give us a good name for > the class > of optimizations that require being listed in > supported_optimizations. > In earlier discussions I called them "brittle", but I can > understand why > nobody wants to call their optimization that, so let's call them > "good-faith optimizations" instead since they rely on the good > faith of...

...lists.llvm.org> wrote: > On 4 Dec 2018, at 13:16, Sanjoy Das wrote: > > On Mon, Dec 3, 2018 at 11:49 PM John McCall jmccall at apple.com wrote: > > Piotr's proposal unfortunately doesn't give us a good name for the class > of optimizations that require being listed in supported_optimizations. > In earlier discussions I called them "brittle", but I can understand why > nobody wants to call their optimization that, so let's call them > "good-faith optimizations" instead since they rely on the good faith of > all the participating code. > > Every...

...transforms that need to know about the existence of good-faith > optimizations > are interprocedural optimizations; furthermore, those optimizations don't > need to know about any good-faith optimizations specifically, they just > need > to understand how to correctly update the supported_optimizations list. > That is a very small burden on IPO that enables an interesting class of > language-specific optimizations. > > John. > _______________________________________________ > cfe-dev mailing list > cfe-dev at lists.llvm.org > http://lists.llvm.org/cgi-bin/mailman/listinfo/...

...ransforms that need to know about the existence of good-faith > optimizations > are interprocedural optimizations; furthermore, those optimizations don't > need to know about any good-faith optimizations specifically, they > just need > to understand how to correctly update the supported_optimizations list. > That is a very small burden on IPO that enables an interesting class of > language-specific optimizations. > Two responses: 1) My comment was on *framing*, not substance.  I'm not debating the *semantics* you've proposed (here), just the way they're described.  The w...