search for: inliner

...ving their applications' performance. In addition, the inlining report can be used by compiler developers to visualize and improve the compiler's default heuristics and option values. For these reasons, I'd like to contribute code to LLVM to generate an inlining report as part of the inliner. Description The inlining report I am proposing contains the following information: (1) The values of the principle threshold options which affect how much inlining is done under various circumstances (2) Whether each function is compiled or has been eliminated by dead static function el...

Hi, I browsed the LLVM inliner implementation, and it seems there is room for improvement. (I have not read it too carefully, so correct me if what I observed is wrong). First the good side of the inliner -- the function level summary and inline cost estimation is more elaborate and complete than gcc. For instance, it consider...

On Nov 23, 2010, at 5:07 PM, Xinliang David Li wrote: > Hi, I browsed the LLVM inliner implementation, and it seems there is room for improvement. (I have not read it too carefully, so correct me if what I observed is wrong). > > First the good side of the inliner -- the function level summary and inline cost estimation is more elaborate and complete than gcc. For instance, i...

On Aug 26, 2009, at 12:01 PM, Devang Patel wrote: >>> I do not understand how the "inlinehint" will help. How will it >>> influence the inliner ? >> >> The hint should make it more attractive to inline. I don't know >> the details >> yet and they will require some experimenting. >> > > In that case you want to add hint to A also. AFAIU, attractiveness of > A and B should match and inliner won...

Xinliang David Li wrote: > Hi, I browsed the LLVM inliner implementation, and it seems there is > room for improvement. (I have not read it too carefully, so correct me > if what I observed is wrong). > > First the good side of the inliner -- the function level summary and > inline cost estimation is more elaborate and complete than gcc. F...

...keyword > > > is > > > fundamentally the wrong direction. > > > > Chandler, thanks for sharing your thought -- however I don't think > > it > > is wrong, let alone 'fundamentally wrong'. Despite all the analysis > > that can be done, the inliner is in the end heuristic based. In > > lack > > of the profile data, when inlining two calls yield the same static > > benefit and size cost, it is reasonable for the inliner to think > > the > > call to the function with inline hint to yield more high > > dynamic...

On Tue, Nov 23, 2010 at 8:07 PM, Xinliang David Li <xinliangli at gmail.com> wrote: > Hi, I browsed the LLVM inliner implementation, and it seems there is room > for improvement.  (I have not read it too carefully, so correct me if what I > observed is wrong). > First the good side of the inliner -- the function level summary and inline > cost estimation is more elaborate and complete than gcc. For in...

...ff? If we had a > 'never inline these functions' list, We don't have such a list, at least not so far. We do have a "used" list but that's presumably used for other things. > a transformation could add any function it wants to this list to > prevent the inliner from inlining it in the future. > > Aside from that, I don't see what uninlining has to do with > inlining heuristics, can you explain a bit more? I'm not sure what there is to explain. Inlining heuristics control what to inline. If you're writing a tool, you'd want...

...till think it's too early to > write C > ++ code with that assumption.) It's actually the other way around. llvm has always ignored the "inline" keyword and now we are finding out we are missing some important cases. Obviously the only correct solution is to make the inliner smarter so it can identify cases which are profitable that's currently ignoring. No one is arguing against that. On the other hand, that is most definitely not a simple solution. So we need an intermediate step. The current plan is to make it behave a bit more like gcc (yeah I know it&...

On Thu, Aug 27, 2009 at 6:00 PM, David Greene<dag at cray.com> wrote: > On Wednesday 26 August 2009 12:59, Dale Johannesen wrote: > >> class X { >> int A(int x) {....} >> inline int B(int x); >> }; >> inline int X::B(int x) {...} >> >> Per the language standard, A and B are semantically identical, both >> "inline".

Hello Syzbot On Fri, 14 Jun 2019 02:26:02 +0800 syzbot wrote: > > Hello, > > syzbot has tested the proposed patch but the reproducer still triggered crash: > memory leak in vhost_net_ioctl > Oh sorry for my poor patch. > ANGE): hsr_slave_1: link becomes ready > 2019/06/13 18:24:57 executed programs: 18 > BUG: memory leak > unreferenced object 0xffff88811cbc6ac0

Hello Syzbot On Fri, 14 Jun 2019 02:26:02 +0800 syzbot wrote: > > Hello, > > syzbot has tested the proposed patch but the reproducer still triggered crash: > memory leak in vhost_net_ioctl > Oh sorry for my poor patch. > ANGE): hsr_slave_1: link becomes ready > 2019/06/13 18:24:57 executed programs: 18 > BUG: memory leak > unreferenced object 0xffff88811cbc6ac0

...t; > > > > > Chandler, thanks for sharing your thought -- however I don't > > > > think > > > > it > > > > is wrong, let alone 'fundamentally wrong'. Despite all the > > > > analysis > > > > that can be done, the inliner is in the end heuristic based. In > > > > lack > > > > of the profile data, when inlining two calls yield the same > > > > static > > > > benefit and size cost, it is reasonable for the inliner to think > > > > the > > > > call...

...l evidence that listening to inline will improve the situation more than just increasing the inlining threshold across the board. Even if we did, I would still be uncomfortable with this: "hasn't been proven entirely competitive yet" implies that we've pursued the current inliner and tried hard to make it better without listening to inline. In fact, the current inliner is almost completely untuned and has many known problems. I am concerned that "listening to inline" will paper over other things that could be solved in much better ways. If the inlining he...

You may have noticed I added an "inlinehint" attribute to the IR yesterday, to represent user declarations that hint inlining would be a good idea ("inline" keyword). Chris and I have been discussing how to hook it up to the C++ FE. Consider: class X { int A(int x) {....} inline int B(int x); }; inline int X::B(int x) {...} Per the language standard, A and B

Hi, I want to have some functions in my code inline so I use the *inline * keyword: *inline void foo() {}* On some functions the compiler inlines the function but it fails to do so on other functions and thus I get a linkage error: *error: undefined reference to 'foo'* What are the conditions that make the compiler refuse inline? Thanks, David p.s. I know that there are ways to pass

Vikram S. Adve wrote: Hmmm. It seems the discussion has grown a little bit larger than I had intended. :) Basically what I think would be useful is an option to the inliner that gives it a list of functions to skip when inlining. My argument for this is that we have several transformations now that search for calls to specific functions; if those functions are inlined, the transform pass can no longer find the calls. I would like the list of functions excluded f...

...vial and limited functionality (think of it as some "bytecode" > expressed in classes). Of course, these method calls of these classes > _must_ be inlined, but there are also "traditional" calls to other > functions which may or may not be meant for inlining. If the inliner > just guesses one of these calls wrong (and it usually does) then > performance will drop by an order of magnitude. That's why all C++ > compilers I know support explicit inline control. I understand where you are coming from. Here are the reasons that I think this is a bogus ar...

Hello Dmitry On Thu, 13 Jun 2019 20:12:06 +0800 Dmitry Vyukov wrote: > On Thu, Jun 13, 2019 at 2:07 PM Hillf Danton <hdanton at sina.com> wrote: > > > > Hello Jason > > > > On Thu, 13 Jun 2019 17:10:39 +0800 Jason Wang wrote: > > > > > > This is basically a kfree(ubuf) after the second vhost_net_flush() in > > > vhost_net_release(). >

Hello Dmitry On Thu, 13 Jun 2019 20:12:06 +0800 Dmitry Vyukov wrote: > On Thu, Jun 13, 2019 at 2:07 PM Hillf Danton <hdanton at sina.com> wrote: > > > > Hello Jason > > > > On Thu, 13 Jun 2019 17:10:39 +0800 Jason Wang wrote: > > > > > > This is basically a kfree(ubuf) after the second vhost_net_flush() in > > > vhost_net_release(). >