similar to: [LLVMdev] llvm.global_ctors and other "appending linkage" global variables?

Hi, I'd like to fix PR19590, which is about llvm.global_ctors containing functions that end up being empty after optimization (which causes the linker to add useless init_array entries to the output binary). globalopt removes empty functions from llvm.global_ctors, but by the time the function becomes empty globalopt has already run and it doesn't run again. I'm wondering what the

On Thu, Dec 10, 2009 at 12:26 AM, Robin Sommer <robinsommer at web.de> wrote: > > On Sat, Dec 05, 2009 at 22:56 -0800, I wrote: > >> the LLVM documentation lists the 'appending' linkage for having the >> linker combine two arrays. I'm wondering though if it's then >> possible to get the size of the combined array, e.g., for iterating >> over

On Wed, Jul 30, 2014 at 3:46 PM, Rafael Espíndola < rafael.espindola at gmail.com> wrote: > > Looking a little deeper, it's not "old-style" exactly; rejecting this > > isn't trivial. > > > > - According to LangRef, the third field is optional [1]. > > > > [1]: > http://llvm.org/docs/LangRef.html#the-llvm-global-ctors-global-variable

+reid, +llvmdev, -llvm-commits > On 2014-Jul-30, at 11:56, Rafael Avila de Espindola <rafael.espindola at gmail.com> wrote: > > >> I think the fix is to upgrade old-style global arrays (or reject >> them?) in the .ll parser. >> > > The .ll format is not stable, so you should be able to just reject it. Looking a little deeper, it's not

> On 2014-Jul-30, at 18:05, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote: > >> On 2014-Jul-30, at 17:19, Reid Kleckner <rnk at google.com> wrote: >> >>> On Wed, Jul 30, 2014 at 3:46 PM, Rafael Espíndola <rafael.espindola at gmail.com> wrote: >>>> Looking a little deeper, it's not "old-style" exactly; rejecting this

On Tue, Feb 18, 2020 at 9:42 PM David Blaikie <dblaikie at gmail.com> wrote: > I'm /guessing/ this might be related to the COFF support specifically > (perhaps COFF has no appending linkage support - in some cases LLVM IR > supports the union of all semantics so that different formats can be fully > expressed - but it means when targeting certain formats, some features are

On Thu, Dec 10, 2009 at 2:05 AM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Thu, Dec 10, 2009 at 12:26 AM, Robin Sommer <robinsommer at web.de> wrote: >> >> On Sat, Dec 05, 2009 at 22:56 -0800, I wrote: >> >>> the LLVM documentation lists the 'appending' linkage for having the >>> linker combine two arrays. I'm wondering

Hi all, Recently I do some jobs based on llvm-link tool. I wonder why link '@llvm.global_ctors' into dest file, even it's not used in dest file? And how can I remove it? Thank you all in advance! Fangqing Xilinx Inc. -------------- next part -------------- An HTML attachment was scrubbed... URL:

> On 2014-Jul-31, at 10:07, Reid Kleckner <rnk at google.com> wrote: > >> On Thu, Jul 31, 2014 at 9:49 AM, Duncan P. N. Exon Smith <dexonsmith at apple.com> wrote: >> Hold on, I'm still not sure what kind of guarantees (restrictions) the C >> API imposes. >> >> If I implement (2), then -verify will fail if someone (e.g.) adds >>

When you link two modules each of which contains a global_ctors array, is there a guarantee as to what order they'll run in?

I talked about this with Nick in person months ago, and my understanding is that GlobalOpt is also an enabling optimization that needs to run early. For example, if we can eliminate an initializer to an internal global with no other stores to it, we can propagate the result. Maybe we should run it twice. On Thu, May 1, 2014 at 11:01 AM, Rafael Espíndola < rafael.espindola at gmail.com>

Thanks Peter, this is very useful feedback. I did manage to change the behavior of LinkOnlyNeeded to correctly import all variables with AppendingLinkage. In fact, I discovered that there was already something fishy. A variable with AppendingLinkage would get imported correctly from the source module if the destination module already contained a definition for that variable and wouldn't be

I have an optimization pass (FunctionPass) where I need to add global constructors. For cleaness sake I decided to add these in my own module. My module is created in my FunctionPass constructor: MyPass() : FunctionPass(ID), myModule("my_module", getGlobalContext()) {} I generate an llvm.global_ctor global variable in my module, and I add my global constructors

Hi Reid, On 03/09/13 20:08, Reid Kleckner wrote: > On Mon, Sep 2, 2013 at 5:18 AM, Duncan Sands <baldrick at free.fr > <mailto:baldrick at free.fr>> wrote: > > Hi Reid, > > On 26/08/13 23:43, Reid Kleckner wrote: > > To implement http://llvm.org/PR16959 > <http://llvm.org/bugs/show___bug.cgi?id=16959 >

Thanks for the hindsight. I am currently working on a patch/potential fix which introduces a new Linker::ImportIntrinsicGlobalVariables flag. The patch includes a unit test reproducing the problem. Hopefully, that will help getting more feedback. Note that it might take a while before I am allowed to upload the patch since I need approval from Autodesk Legal department. Cheers, Benoit Benoit

On Mon, Sep 2, 2013 at 5:18 AM, Duncan Sands <baldrick at free.fr> wrote: > Hi Reid, > > On 26/08/13 23:43, Reid Kleckner wrote: > >> To implement http://llvm.org/PR16959 >> <http://llvm.org/bugs/show_**bug.cgi?id=16959<http://llvm.org/bugs/show_bug.cgi?id=16959>>, >> I need to add a new field to >> >> global_ctors. >> >>

To implement http://llvm.org/PR16959<http://llvm.org/bugs/show_bug.cgi?id=16959>, I need to add a new field to global_ctors. Static data members of class template instantiations can have initializers that must only run once on program startup. Itanium solves this with guard variables and the emission of multiple initializers, only one of which actually initializes the data at runtime.

Hi all, the LLVM documentation lists the 'appending' linkage for having the linker combine two arrays. I'm wondering though if it's then possible to get the size of the combined array, e.g., for iterating over its elements? Or how would I otherwise use the combined array? Thanks, Robin -- Robin Sommer * Phone +1 (510) 666-2886 * robin at icir.org ICSI/LBNL * Fax +1

On Sat, Dec 05, 2009 at 22:56 -0800, I wrote: > the LLVM documentation lists the 'appending' linkage for having the > linker combine two arrays. I'm wondering though if it's then > possible to get the size of the combined array, e.g., for iterating > over its elements? Or how would I otherwise use the combined array? Any thoughts on this? Am I missing something?

On Thu, May 1, 2014 at 11:12 AM, Rafael Espíndola <rafael.espindola at gmail.com> wrote: > On 1 May 2014 14:08, Reid Kleckner <rnk at google.com> wrote: >> I talked about this with Nick in person months ago, and my understanding is >> that GlobalOpt is also an enabling optimization that needs to run early. >> For example, if we can eliminate an initializer to an