similar to: How to emit opt report when using LTO

Thanks! On Mon, Jan 27, 2020 at 6:05 PM Teresa Johnson <tejohnson at google.com> wrote: > By default even regular LTO now has module summaries (like the kind used > for ThinLTO). LTO will then run index based dead symbol analysis here: > http://llvm-cs.pcc.me.uk/lib/LTO/LTO.cpp#923. Then when linkRegularLTO is > called here: http://llvm-cs.pcc.me.uk/lib/LTO/LTO.cpp#935, it

On Mon, Oct 3, 2016 at 5:24 PM, Xinliang David Li <xinliangli at gmail.com> wrote: > Small repro: > > __attribute__((weak)) int hello_world(); > > int test() { > if (hello_world) > return hello_world(); > return 0; > } > > $ clang -fuse-ld=gold -flto=thin -O2 -shared -fPIC -o libmore.so more.c > $ objdump -t libmore.so |grep hello >

Hello Teresa, > Without -flto, a.o ends up with a reference to __exp_finite, That’s correct. > which also would not be satifisfied out of libexp.a. That’s not correct. Even if libexp.a would have __exp_finite, it wouldn’t be resolved from libexp.a, because of the behavior described in my first message. > Do you also have an implementation of __exp_finite in your libexp.a? No, I don’t

GCC LTO works ok for the test case with both bfd and gold linker. David On Tue, Oct 4, 2016 at 6:58 AM, Teresa Johnson <tejohnson at google.com> wrote: > > > On Mon, Oct 3, 2016 at 6:15 PM, Teresa Johnson <tejohnson at google.com> > wrote: > >> >> >> On Mon, Oct 3, 2016 at 5:24 PM, Xinliang David Li <xinliangli at gmail.com> >> wrote:

On Mon, Oct 3, 2016 at 3:53 PM, Xinliang David Li <xinliangli at gmail.com> wrote: > What is the linker command line buidling liblldb.so? is libgcc.a passed in? > There is no difference in the linker command for liblldb.so or bin/lldb between the ld.bfd and ld.gold cases, and neither links libgcc.a that I can see. The difference appears to be that the __morestack symbol is weak in

Hi, I wanted to get the linked result in LLVM bitcode format. With LTO, this can be done by -flto -Wl,-plugin-opt,emit-llvm. Instead of generating native executables, it outputs a file with bitcode format. Does this still work with -flto=thin? -flto=thin -Wl,-plugin-opt,emit-llvm outputs a bitcode file, but its file size is too small, and does not contain all contents. What is the correct way

Hi! LLVM newbie here, I was mainly working on the frontend so far. We had a small hackathon project idea to piggyback on LTO to detect dead code (unused functions). The basic idea is to compile the code for every target and dump the removed functions. Intersect the function symbol names for each target and those functions should be safe to remove from the source code (unless there were some

Hopefully someone else on the dev list who has experience with LNT and the LLVM test-suite will chime in. I've never run it myself. Adding Mehdi since he ran it with LTO/ThinLTO. I found some documentation for the test-suite: https://llvm.org/docs/TestingGuide.html#test-suite-overview http://llvm.org/docs/lnt/quickstart.html http://llvm.org/docs/lnt/tests.html#llvm-cmake-test-suite But I

Yes running LLVM performance test suite with LTO and Thin LTO enabled. Thanks, Siddharth On Fri, May 11, 2018 at 7:32 PM, Teresa Johnson <tejohnson at google.com> wrote: > I'm not completely sure what you are asking. Are you looking for > performance benchmarks to use for LTO and ThinLTO testing? Or are you > asking how to build/run with LTO and ThinLTO? Are you asking how to

Hello llvm-dev@ I have a pass that puts a global constant data array into the module. And another pass that gets runned by lld during LTO stage. When I look at bytecode files corresponding to source TUs produced by `clang -flto`, I can see GVs inserted by my pass #1. However, when pass #2 gets to run, these GV's are gone. I figured out that passing -mllvm -compute-dead=0 to the linker fixes

Looks like this is indeed related to r360841. In C, there are distinctions between declarations, definitions and tentative definitions. Global variables declared with "extern" are declarations. Global variables that don't have "extern" and have initializers are definitions. If global variables have neither "extern" nor initializers, they are called tentative

> On Aug 26, 2016, at 2:06 PM, Teresa Johnson <tejohnson at google.com> wrote: > > Mehdi: I see what is going on: > > + ArrayType *Ty = > + ArrayType::get(Type::getInt8Ty(RegularLTO.Ctx), I.second.Size); > + GlobalVariable *OldGV = RegularLTO.CombinedModule->getNamedGlobal(I.first); > + if (OldGV && OldGV->getType()->getElementType()

Dear community, Recently I discovered that llvm gold linker plugin (LLVMgold.so) doesn't add llvm instrinsics symbols to the linker symbol table. I do not claim that something is necessary wrong, just want to share my observations with the community. Brief summary If I create a static library with a custom version of 'exp()' math function and link it as follows: $

Hi I use the LDFLAGS=" -flto -fuse-ld=gold -Wl,-plugin-opt=save-temps " to generate the makefile and to make the whole program. However, found four different kinds of bitcode for each target. For example, I am compiling coreutils. For the program "nohup", I can get nohup.0.0.preopt.bc nohup.0.2.internalize.bc nohup.0.4.opt.bc nohup.0.5.precodegen.bc If I am right, I

Hi Teresa, Can you please let me know if there is any update on this issue. Thanks M Suresh From: Teresa Johnson <tejohnson at google.com> Sent: Tuesday, June 11, 2019 7:23 PM To: Rui Ueyama <ruiu at google.com> Cc: Mani, Suresh <Suresh.Mani at amd.com>; llvm-dev <llvm-dev at lists.llvm.org> Subject: Re: [llvm-dev] Expected behavior of lld during LTO for global symbols

To compile an auto-tooled project to bitcode, I used to use plugin-opt=save-temps switch as explained in: http://gbalats.github.io/2015/12/10/compiling-autotooled-projects-to-LLVM-bitcode.html. This switch works with LLVM 3.8.0. However, it seems to have no effect with LLVM 5.0.0. I can see intermediate bitcode files on disk, but not the final one. Is the option removed altogether? Has the switch

Thanks for the test case! I can reproduce this, and see with the compiler I saved from just before r278338 that this is indeed a chance in behavior. Looking at why this changed... On Fri, Aug 26, 2016 at 1:42 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> On Aug 26, 2016, at 1:34 PM, junbuml at codeaurora.org wrote: >> >> On 2016-08-26 12:47, Mehdi Amini wrote:

LLD revision is r331862. To add, I had initially tried it on r328903, which also reproduced the issue. On Wed, May 9, 2018 at 9:26 AM Pirama Arumuga Nainar <pirama at google.com> wrote: > Hi Teresa, > > Thanks for looking into this. I hadn't initially tried ToT, but it > reproduces in ToT as well when I tried. > > $ ./clang --version > > clang version 7.0.0

No worries, thanks for the update. Teresa On Mon, Sep 26, 2016, 7:16 AM Carsten Mattner <carstenmattner at gmail.com> wrote: > On Mon, Sep 26, 2016 at 3:52 PM, Teresa Johnson <tejohnson at google.com> > wrote: > > > > ThinLTO needs to create as many temporary files as there are input > > modules to the link. From your 'ls' below, it doesn't look

On Wed, May 9, 2018 at 6:43 AM Teresa Johnson <tejohnson at google.com> wrote: > Hi Pirama, > > I can't reproduce with either lld or gold, using a compiler built from > head. What version is your clang? > (and your lld) > > Thanks, > Teresa > > On Tue, May 8, 2018 at 7:50 PM Pirama Arumuga Nainar via llvm-dev < > llvm-dev at lists.llvm.org>