search for: lto

Hi, Encounter a compilation issue related to c++. Software versions: - gcc 4.7.4 - llvm git commit 98a1ca117e6743dd7f2d505443a96f591d083eab Build log: Scanning dependencies of target LLVMLTO [ 53%] Building CXX object lib/LTO/CMakeFiles/LLVMLTO.dir/Caching.cpp.o /tmp/pkgs/llvm/lib/LTO/Caching.cpp: In lambda function: /tmp/pkgs/llvm/lib/LTO/Caching.cpp:74:7: error: looser throw specifier for 'virtual llvm::lto::localCache(std::string, llvm::lto::AddFileFn)::<lambda(unsigned int,...

...------------ The goal of the changes described in this RFC is to support aggressive Whole Program Devirtualization without requiring -fvisibility=hidden at compile time, by pre-enabling bitcode for whole program devirtualization, but delaying the decision on whether to apply devirtualization until LTO link time. This is needed both because we may not know whether the link mode is safe for hidden LTO visibility until link time, and also to allow bitcode objects to be shared between links of targets with differing valid LTO visibility. This utilizes the !vcall_visibility metadata added for Dead Vi...

...nt of disassembly work, conceptually the framework should not be too hard to be ported to another target. One thing I was not aware of (perhaps the description did not make it clear) is that Propeller intends to **reorder basic block sections across translation units**. This is something that full LTO can do while ThinLTO cannot. Our internal systems cannot afford doing a full LTO (**Can we fix the bottleneck of full LTO** [1]?) for large executables and I believe some other users are in the same camp. Now, with ThinLTO, the post link optimization scheme will inevitably require help from the li...

Hi: &nbsp; &nbsp; I want to learn&nbsp; how LTO and thinLTO work? But I'm confused how lld invoked either library. How can I find it in lld. Should i be familiar with lld source code? And i also think if there is some easy test case and with step-by- step debugging or some log messages can help me learn this? Is there some method can do stuf...

Hi, I have a question regarding the behavior of weak symbol resolution in LTO: Suppose there are weak definitions in both the source code and some native lib. In non-LTO path, we will use the version from source code. In LTO path, LLVM may discard the definition as it has "linkeonce" linkage type. So the native version will be selected by linker. Now, non-LTO an...

...can not be parsed with current llvm asm parser, because it starts with % (moreover it has mnemonic in second place) Say you written pass, that makes it "mnem %x, %y, %z". Now this guy can be parsed, but can not be encoded by gas. You simply havent that instruction in you assembler. For LTO it isn't a problem: you can make arbitrary MCInst from everything that comes into ParseInstruction. But it is problem for regular scenario where wrong asm will be printed and then passed to gas. So I want to apply this on 2nd lto stage where AsmParser is inevitable and to not apply in non-LTO...

> > > I often use the gold plugin's also-emit-llvm option to verify the final > LLVM bitcode of a program. However, I realized that the gold plugin generates >> the >> bitcode file before running LTO optimizations, such that the changes >> performed >> by LTO are not reflected in the bitcode file. >> >> What is the reason for this behavior? >> > > my guess: if the LTO optimizers crash, this is very helpful for debugging > because it gives you the input to...

Is there a way to get object files from the LTO step before the linker performs the final link phase? What I'd like to do is given these bitcode files: a.lto.o, b.lto.o, c.lto.o run LTO on them and get out the object files: a.o, b.o, c.o (These .o files hold the code that is sent directly to the final link phase.) If there doesn'...

...ss. It is no difference what is level, problem is the same. After fixing for asm parser, assembler syntax is no more valid for backend, without processing with asm parser. May be it will be solution to process inline asm on insn printer level to remove syntax fixes. But just switch it off without lto will make compiler do less job P.S. sorry for dup, maillist CC lost on first sent. --- WIth best regards, Konstantin On Mon, Sep 12, 2016 at 8:52 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> On Sep 12, 2016, at 9:26 AM, Konstantin Vladimirov <konstantin.vladimirov at...

I tried building llvm, clang, lld, lldb from the 3.9 svn release branch with LTO, and some of the results were unexpected. I first tried to rebuild llvm with llvm-3.9, which has ThinLTO, by providing -DLLVM_ENABLE_LTO=Thin, but that failed very quickly, so I fell back to building with -DLLVM_ENABLE_LTO=On and using the system CC/CXX (gcc 6.1). The resulting installed build is...

...Sat, Sep 10, 2016 at 6:25 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> On Sep 10, 2016, at 3:03 AM, Carsten Mattner via llvm-dev <llvm-dev at lists.llvm.org> wrote: >> >> I tried building llvm, clang, lld, lldb from the 3.9 svn release >> branch with LTO, and some of the results were unexpected. >> >> I first tried to rebuild llvm with llvm-3.9, which has ThinLTO, by >> providing -DLLVM_ENABLE_LTO=Thin, but that failed very quickly, so I >> fell back to building with -DLLVM_ENABLE_LTO=On and using the system >> CC/CXX...

Hi, Thanks for the info, If i only want to run performance test on benchmarks for LTO and Thin LTO enabled target, Can u suggest ways to do it ? I want to do it at my end. Thanks, Siddharth On Wed, May 2, 2018 at 7:03 PM, Teresa Johnson <tejohnson at google.com> wrote: > I've only measured performance on x86. There are some old results for SPEC > cpu2006 in the blo...

Hi, In LTO we have AsmParser that process inline assembler instructions to MCInst and I want to fix some inline assembler in order to conform its rules (do not start with non-identifier and so on) because asm syntax of our backend allows some incompatible patterns. In order to do this I am adding IR-level tar...

On Mon, Aug 6, 2018 at 4:30 PM Quentin Colombet <quentin.colombet at gmail.com> wrote: > Hi Bill, > > > 2018-08-06 16:13 GMT-07:00 Bill Wendling via llvm-dev < > llvm-dev at lists.llvm.org>: > > Is there a way to get object files from the LTO step before the linker > > performs the final link phase? What I'd like to do is given these bitcode > > files: > > > > a.lto.o, b.lto.o, c.lto.o > > > > run LTO on them and get out the object files: > > > > a.o, b.o, c.o > > > > (...

I am wondering how the following issue was handled for libLTO? We have a working patch to implement the FSF gcc LTO on darwin which now passes all of the liblto testsuite but are seeing linker issues with larger programs like aermod... as -arch x86_64 -force_cpusubtype_ALL -o aermod.o aermod.s /usr/bin/ld -dynamic -arch x86_64 -macosx_version...

...ndya at gmail.com> wrote: > > > > Hello Mentors, > > > > I have a very naive idea to get IPRA woking at link time and thus > extending its scope to intermodule. I seek some help if it seems to be a > feasible idea. > > > > So idea is to take advantage of LTO's capability to work with bit code > files. LTO can optimize number of bitcode files and combine them into a big > module. LTO then generates native code for the big module. > > Yes, that’s how LTO works. > > > > > So does it seem feasible to have clang generates bit...

Hi, I have tried to build libjpeg-turbo <https://github.com/libjpeg-turbo/libjpeg-turbo> with LTO in LLVM, using both clangbut get many errors in lld that look like the following: ld: error: undefined symbol: jpeg_std_error >>> referenced by jcstest.c:76 >>> lto.tmp:(main) ld: error: undefined symbol: jpeg_CreateCompress >>> referenced by jcstest.c:86...

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 bu...

The Apple ld (shipped with Xcode, open-source) saves the 3 files if -save-temps is applied: - xxx.lto.bc : the merged bit-code before IPA - xxx.lto.opt.bc: the optimized bit-code of the *.lto.bc - xxx.lto.o : the object file of xxx.lto.bc I think it is better way to go, often time we need IR both after and after the transformation. On 6/4/13 3:37 AM, Jonas Wagner wrote: > > >...

Hi, I have a module pass and I hope to use it to optimize a real-world program. I need LTO，and I have got LTO plugin. But How can I add my passes to LTO Pass. I can't find solution. What should I do? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20200422/76d2b046/attachment.html>