similar to: [LLVMdev] Proposal: support object file-based on-disk module format

On Tue Nov 25 2014 at 18:30:08 Carlo Alberto Ferraris <cafxx at strayorange.com> wrote: > Just curious: are you considering the possibility of enabling LTO across > user and runtime code? > Since AFAIK the product of go build is almost always a statically-linked > executable, I guess it would make sense (when doing an optimised build) to > feed the runtime to the linker in IR

Hi all, I wanted to make this proposal to extend ThinLTO to allow a bitcode module to embed another bitcode module containing summary information. The purpose of doing so is to support CFI and whole-program devirtualization optimizations under ThinLTO. Overview The CFI and whole-program devirtualization optimizations work by transforming vtables according to the class hierarchy. For example,

Hi Peter It is not currently related because we started the implementation before Thin-LTO gets proposed in the community but our "__LLVM, __bitcode" section is pretty much the same as ".llvmbc" section. Note ".llvmbc" doesn't really follow the section naming convention for MachO objects. I am hoping to unify them during the upstream of the implementation.

The design objective is to make thinLTO mostly transparent to binutil tools to enable easy integration with any build system in the wild. 'Pass-through' mode with 'ld -r' instead of the partial LTO mode is another reason. David On Thu, May 14, 2015 at 7:30 AM, Teresa Johnson <tejohnson at google.com> wrote: > On Thu, May 14, 2015 at 7:22 AM, Eric Christopher

On Wed, May 13, 2015 at 10:46 PM, Alex Rosenberg <alexr at leftfield.org> wrote: > "ELF-wrapped bitcode" seems potentially controversial to me. > > What about ar, nm, and various ld implementations adds this requirement? > What about the LLVM implementations of these tools is lacking? > Sorry I can not parse your questions properly. Can you make it clearer? David

I've included below an RFC for implementing ThinLTO in LLVM, looking forward to feedback and questions. Thanks! Teresa RFC to discuss plans for implementing ThinLTO upstream. Background can be found in slides from EuroLLVM 2015: https://drive.google.com/open?id=0B036uwnWM6RWWER1ZEl5SUNENjQ&authuser=0) As described in the talk, we have a prototype implementation, and would like to

So, what Alex is saying is that we have these tools as well and they understand bitcode just fine, as well as every object format - not just ELF. :) -eric On Thu, May 14, 2015, 6:55 AM Teresa Johnson <tejohnson at google.com> wrote: > On Wed, May 13, 2015 at 11:23 PM, Xinliang David Li > <xinliangli at gmail.com> wrote: > > > > > > On Wed, May 13, 2015 at

On Thu, May 14, 2015 at 11:14 AM, Eric Christopher <echristo at gmail.com> wrote: > I'm not sure this is a particularly great assumption to make. Which part? > We have to > support a lot of different build systems and tools and concentrating on > something that just binutils uses isn't particularly friendly here. I think you may have misunderstood His point was exactly

The end goal is the ability to turn on thin-lto as easy as turning optimizations like -O2 or -O3 -- we want friendliness, very much :) David On Thu, May 14, 2015 at 11:14 AM, Eric Christopher <echristo at gmail.com> wrote: > I'm not sure this is a particularly great assumption to make. We have to > support a lot of different build systems and tools and concentrating on >

As promised, here is an new version of the ThinLTO RFC, updated based on some of the comments, questions and feedback from the first RFC. Hopefully we have addressed many of these, and as noted below, will fork some of the detailed discussion on particular aspects into separate design doc threads. Please send any additional feedback and questions on the overall design. Thanks! Teresa Updated RFC

On Thu, May 14, 2015 at 12:53 PM, Eric Christopher <echristo at gmail.com> wrote: > > > On Thu, May 14, 2015 at 11:34 AM Daniel Berlin <dberlin at dberlin.org> > wrote: > >> On Thu, May 14, 2015 at 11:14 AM, Eric Christopher <echristo at gmail.com> >> wrote: >> > I'm not sure this is a particularly great assumption to make. >>

On Thu, May 14, 2015 at 1:18 PM, Eric Christopher <echristo at gmail.com> wrote: > > > On Thu, May 14, 2015 at 1:11 PM David Blaikie <dblaikie at gmail.com> wrote: >> >> On Thu, May 14, 2015 at 12:53 PM, Eric Christopher <echristo at gmail.com> >> wrote: >>> >>> >>> >>> On Thu, May 14, 2015 at 11:34 AM Daniel Berlin

On Fri, May 29, 2015 at 6:56 AM, Alex Rosenberg <alexr at leftfield.org> wrote: > My earlier statement about wrapping things in a native object file held in that it is controversial. It appears to be still central to your design. > > It may help to look at the problem from a different viewpoint: LLVM is not a compiler. It is a framework that can be used to make compiler-like tools.

Hi! I've been working on coroutines for some time, and it seems you were right - it makes much more sense to have regular C (and assembly) code for handling coroutines. For instance, I'd otherwise would have to make an assumption about the threading model the platform has (or assume there are no threads at all, which prevents me from allowing goroutine like ("run parallel till you

On Thu, May 14, 2015 at 2:09 PM, Eric Christopher <echristo at gmail.com> wrote: > > > On Thu, May 14, 2015 at 1:35 PM Teresa Johnson <tejohnson at google.com> wrote: >> >> On Thu, May 14, 2015 at 1:18 PM, Eric Christopher <echristo at gmail.com> >> wrote: >> > >> > >> > On Thu, May 14, 2015 at 1:11 PM David Blaikie

On Wed, Jun 3, 2015 at 4:19 AM, Dave Bozier <seifsta at gmail.com> wrote: > Hi Teresa, > > Thanks for providing this updated RFC. > >> For Sony's linker, are you using the gold plugin or libLTO interfaces? >> If the latter, I suppose some ThinLTO handling would have to be added >> to your linker (e.g. to invoke the LLVM hooks to write the stage-2 >>

On Fri, Aug 14, 2015 at 3:35 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > Hi Teresa, > > Thanks for layout down a detailed proposal on top of the slides, it is > very instructive and very pleasant to read. > Hi Mehdi, Thanks! > > I have a few questions, none of which touches the ELF aspect! :) > I apologize if you already addressed them and I missed it (if

On Tue, Jul 08, 2014 at 07:21:00PM +0100, Dan Liew wrote: > Hi Peter, > > This sounds sensible to me. > > There is one thing that does concern me though. IIRC when you create > object files with additional sections the GNU ld linker (possibly > others too) will concatenate sections it doesn't recognise into the > final executable. > There is actually a hacky tool

My earlier statement about wrapping things in a native object file held in that it is controversial. It appears to be still central to your design. It may help to look at the problem from a different viewpoint: LLVM is not a compiler. It is a framework that can be used to make compiler-like tools. >From that view, it no longer makes sense to discuss "the plugin," or gold, or $AR,

On Thu, May 14, 2015 at 2:09 PM, Eric Christopher <echristo at gmail.com> wrote: > > > On Thu, May 14, 2015 at 1:35 PM Teresa Johnson <tejohnson at google.com> > wrote: > >> On Thu, May 14, 2015 at 1:18 PM, Eric Christopher <echristo at gmail.com> >> wrote: >> > >> > >> > On Thu, May 14, 2015 at 1:11 PM David Blaikie