similar to: Emit LLVM bitcode after ThinLTO

This looks similar to the problem I fixed awhile back in r292408. I'll take a look (probably tomorrow since I am taking some vacation today). Teresa On Tue, May 16, 2017 at 9:43 AM, David Blaikie <dblaikie at gmail.com> wrote: > +Teresa > > On Mon, May 15, 2017 at 9:20 AM David Callahan via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> I am tracking a

Thanks! Question about the final link step: Do I provide all the object files to the link step, i.e. something like: clang++ -o thinlto main-native.o lib/lib-native.o src/lib-native.o Do I need to provide --start-lib markers on that final link step as well? Tanoy On Tue, Jun 18, 2019 at 10:37 AM Teresa Johnson <tejohnson at google.com> wrote: > Hi Tanoy, > > You can't use

Fails with gold too: Library-native.o:Library.cpp:regway: error: undefined reference to 'vtable for regwayobj' /home/dcallahan/fbsource/fbcode/third-party-buck/platform007/tools/binutils/bin/gold/ld: the vtable symbol may be undefined because the class is missing its key function clang-8: error: linker command failed with exit code 1 (use -v to see invocation) From: Teresa Johnson

I'm trying to run distributed ThinLTO without thin archives. When I do, I get an error in the optimizer when clang tries to open a nonexistent file: clang++ -flto=thin -Xclang -fno-lto-unit -O3 -c main.cpp -o main.o clang++ -flto=thin -Xclang -fno-lto-unit -O3 -c lib/lib.cpp -o lib/lib.o clang++ -flto=thin -Xclang -fno-lto-unit -O3 -c src/lib.cpp -o src/lib.o llvm-ar -format gnu qcs lib.a

Hi Teresa, Thanks for the detailed reply! > How are you creating your bitcode files? I create the bitcode with `-flto=thin -c` and sure it has a GLOBALVAL_SUMMARY_BLOCK. And there’s no RegularLTO partition only ThinLTO bicode. > Where is it aborting in the backend? It aborts at ` report_fatal_error("Failed to setup codegen")` in of codegen() of LTOBackend.cpp. And before that in

Thanks Teresa Yes it is astar, happen to send a tar of the sources but they are just copies from the spec distribution The ld command is: GNU ld (GNU Binutils) 2.29.1 Thanks for the guidance on path names. The prefix-replace just effects the string written to the object files right? So we could post-process that file with other tools as well, correct? Thanks again --david From: Teresa Johnson

I am trying to work through the usage of thinlto for distributed builds. Here is the simple thinlto usage, just add -flto=thin everywhere, easy: clang++ -flto=thin -O3 -c -o CreateWay_.o -DSPEC_CPU -DNDEBUG -DSPEC_CPU_LITTLE_ENDIAN -Wno-dangling-else CreateWay_.cpp clang++ -flto=thin -O3 -c -o Places_.o -DSPEC_CPU -DNDEBUG -DSPEC_CPU_LITTLE_ENDIAN

Hi, I'm working on enabling thinLTO for our custom backend on LLVM-8 with lld to get code size benefits from dead symbol elimination. The code in LTO::run() of LTO.cpp confuses me that, even though thinLTO is specified, runRegularLTO() will be run first and its return value determines whether runThinLTO() will be executed. My question is if it's clearly known that thinLTO is used, is it

On Wed, Jul 12, 2017 at 10:19 AM, Teresa Johnson <tejohnson at google.com> wrote: > Hi Christu, > > Thanks for the note! > > On Wed, Jul 12, 2017 at 9:56 AM, Christudasan D via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > >> Hello, >> >> >> >> My impression on *thinLTO* when I first heard of it, (EuroLLVM2015) was >> about

On Thu, Jul 13, 2017 at 8:37 AM, Christudasan D <xander.cd at gmail.com> wrote: > > Hi Teresa, > > Yes, we plan to have our code at CG directly. > We use our own linker. That's the pain. We might only get a partial > benefit of thinLTO which occurs at compile time. > There is no compile-time only benefit of ThinLTO. You'll need the linker to interface with the

Hello, My impression on *thinLTO* when I first heard of it, (EuroLLVM2015) was about achieving Cross Module Optimization (CMO) at the IR level. Having parallel front-end compilation & initial optimization first, a thin-link of individual input units, more optimization by calling opt again on the combined IR, and finally the target codegen using llc. A transformation similar to the

On Thu, Jul 13, 2017 at 2:54 AM, Christudasan D <xander.cd at gmail.com> wrote: > Thank you Teresa. > > Yes, I would like to save the IR (*.bc and/or *.ll) after all > optimizations (especially thinLTO) are done and call *llc* separately. > Is there any specific document available online to see more about this > feature and various command-line switches that a compiler

Adding Peter to comment on the linker resolution issue. >From adding save-temps, it looks like lld and gold are giving different resolutions to the symbols, which is presumably creating this issue: (first file is with lld and second is with gold) $ diff a.out.resolution.txt gold/ 4c4 < -r=a.o,__llvm_profile_raw_version,plx --- > -r=a.o,__llvm_profile_raw_version,l 8,9c8,9 <

This is usually a problem that is not using llvm-ar. I cannot reproduce this problem with either llvm 10.0 or TOT version. Which linker version are you using? You can also try pass "-Wl,-debug_snapshot" to the command where the error produces and then locate the "*.ld-snapshot" in /tmp directory and attach that as a reproducer. Steven > On Jul 22, 2020, at 8:41 AM, Teresa

I think for ld64, you can mix thinLTO and fullLTO files and ld64 is going to compile them separately and combine the result. (Mehdi can confirm). I think this is aligned with the fact that whether to use full or thin LTO is decided during clang invocation, not linker invocation. I am not against any of the model, but I think we need to do some research before making the effort to switch the model.

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

On Tue, Apr 10, 2018 at 11:52 PM, Mehdi AMINI <joker.eph at gmail.com> wrote: > > > Le mar. 10 avr. 2018 à 23:18, <katya.romanova at sony.com> a écrit : > >> Hi Mehdi, >> >> >> >> Awesome! It’s a very clear design. The only question left is which >> pipeline to choose for unified compile-phase optimization pipeline. >> >> -

David, Thanks for looking into this. I did a small reproduction on my machine outside of my build system. So here is how to reproduce: Download https://downloads.xiph.org/releases/ogg/libogg-1.3.4.tar.xz Download llvm-10.0.1 macOS binary export PATH=<path to llvm/bin>:$PATH export SDKROOT=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk untar

Looks like your static library is not even pulled into the link command so the static library is not even in the snapshot. From the link command in the snapshot, the static library is not on the command line from snapshot: /Applications/Xcode-11.3.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld -Z -demangle -object_path_lto

Hi Teresa, Thank you so much for your reply! I am on vacation until the end of this week and on EuroLLVM next week, so I have to apologize in advance that my replies are delayed. >>Right - see my reply on this from last night, at the very least the ThinLTO importing thresholds will need retuning if we will >>perform optimizations like unrolling/vectorization/etc that tend to