[lld] r296702 - ELF: Add ThinLTO caching support.

Chandler Carruth via llvm-commits llvm-commits at lists.llvm.org
Mon Oct 15 02:05:41 PDT 2018


Ping!

I continue to see spurious failures of the LTO cache tests for LLD on every
architecture that supports it. This is a really frustrating thing to have
just sit in tree and constant break bots and developers.

On Tue, Sep 4, 2018 at 5:58 AM Chandler Carruth <chandlerc at gmail.com> wrote:

> Sorry to dig up an old commit, but...
>
> On Thu, Mar 2, 2017 at 12:11 AM Peter Collingbourne via llvm-commits <
> llvm-commits at lists.llvm.org> wrote:
>
>> Author: pcc
>> Date: Wed Mar  1 17:00:10 2017
>> New Revision: 296702
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=296702&view=rev
>> Log:
>> ELF: Add ThinLTO caching support.
>>
>> This patch adds an option named --thinlto-cache-dir, which specifies the
>> path to a directory in which to cache native object files for ThinLTO
>> incremental builds.
>>
>> Differential Revision: https://reviews.llvm.org/D30509
>>
>> Added:
>>     lld/trunk/test/ELF/lto/Inputs/cache.ll
>>     lld/trunk/test/ELF/lto/cache.ll
>>
>
> I  have found this test to be frustratingly flaky. Most recent example:
> http://lab.llvm.org:8011/builders/clang-with-thin-lto-ubuntu/builds/12451
>
> It is particularly interesting that it is flaky on this linux bot.
>
> Anything else we can do here?
>
>
>> Modified:
>>     lld/trunk/ELF/Config.h
>>     lld/trunk/ELF/Driver.cpp
>>     lld/trunk/ELF/LTO.cpp
>>     lld/trunk/ELF/LTO.h
>>     lld/trunk/ELF/Options.td
>>
>> Modified: lld/trunk/ELF/Config.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Config.h?rev=296702&r1=296701&r2=296702&view=diff
>>
>> ==============================================================================
>> --- lld/trunk/ELF/Config.h (original)
>> +++ lld/trunk/ELF/Config.h Wed Mar  1 17:00:10 2017
>> @@ -86,6 +86,7 @@ struct Configuration {
>>    llvm::StringRef OptRemarksFilename;
>>    llvm::StringRef SoName;
>>    llvm::StringRef Sysroot;
>> +  llvm::StringRef ThinLTOCacheDir;
>>    std::string RPath;
>>    std::vector<VersionDefinition> VersionDefinitions;
>>    std::vector<llvm::StringRef> AuxiliaryList;
>>
>> Modified: lld/trunk/ELF/Driver.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Driver.cpp?rev=296702&r1=296701&r2=296702&view=diff
>>
>> ==============================================================================
>> --- lld/trunk/ELF/Driver.cpp (original)
>> +++ lld/trunk/ELF/Driver.cpp Wed Mar  1 17:00:10 2017
>> @@ -583,6 +583,7 @@ void LinkerDriver::readConfigs(opt::Inpu
>>    Config->Sysroot = getString(Args, OPT_sysroot);
>>    Config->Target1Rel = getArg(Args, OPT_target1_rel, OPT_target1_abs,
>> false);
>>    Config->Target2 = getTarget2(Args);
>> +  Config->ThinLTOCacheDir = getString(Args, OPT_thinlto_cache_dir);
>>    Config->ThinLTOJobs = getInteger(Args, OPT_thinlto_jobs, -1u);
>>    Config->Threads = getArg(Args, OPT_threads, OPT_no_threads, true);
>>    Config->Trace = Args.hasArg(OPT_trace);
>>
>> Modified: lld/trunk/ELF/LTO.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LTO.cpp?rev=296702&r1=296701&r2=296702&view=diff
>>
>> ==============================================================================
>> --- lld/trunk/ELF/LTO.cpp (original)
>> +++ lld/trunk/ELF/LTO.cpp Wed Mar  1 17:00:10 2017
>> @@ -18,6 +18,7 @@
>>  #include "llvm/ADT/StringRef.h"
>>  #include "llvm/ADT/Twine.h"
>>  #include "llvm/IR/DiagnosticPrinter.h"
>> +#include "llvm/LTO/Caching.h"
>>  #include "llvm/LTO/Config.h"
>>  #include "llvm/LTO/LTO.h"
>>  #include "llvm/Object/SymbolicFile.h"
>> @@ -142,11 +143,24 @@ std::vector<InputFile *> BitcodeCompiler
>>    std::vector<InputFile *> Ret;
>>    unsigned MaxTasks = LTOObj->getMaxTasks();
>>    Buff.resize(MaxTasks);
>> +  Files.resize(MaxTasks);
>>
>> -  checkError(LTOObj->run([&](size_t Task) {
>> -    return llvm::make_unique<lto::NativeObjectStream>(
>> -        llvm::make_unique<raw_svector_ostream>(Buff[Task]));
>> -  }));
>> +  // The --thinlto-cache-dir option specifies the path to a directory in
>> which
>> +  // to cache native object files for ThinLTO incremental builds. If a
>> path was
>> +  // specified, configure LTO to use it as the cache directory.
>> +  lto::NativeObjectCache Cache;
>> +  if (!Config->ThinLTOCacheDir.empty())
>> +    Cache = lto::localCache(Config->ThinLTOCacheDir,
>> +                            [&](size_t Task, StringRef Path) {
>> +                              Files[Task] =
>> check(MemoryBuffer::getFile(Path));
>> +                            });
>> +
>> +  checkError(LTOObj->run(
>> +      [&](size_t Task) {
>> +        return llvm::make_unique<lto::NativeObjectStream>(
>> +            llvm::make_unique<raw_svector_ostream>(Buff[Task]));
>> +      },
>> +      Cache));
>>
>>    for (unsigned I = 0; I != MaxTasks; ++I) {
>>      if (Buff[I].empty())
>> @@ -160,5 +174,10 @@ std::vector<InputFile *> BitcodeCompiler
>>      InputFile *Obj = createObjectFile(MemoryBufferRef(Buff[I],
>> "lto.tmp"));
>>      Ret.push_back(Obj);
>>    }
>> +
>> +  for (std::unique_ptr<MemoryBuffer> &File : Files)
>> +    if (File)
>> +      Ret.push_back(createObjectFile(*File));
>> +
>>    return Ret;
>>  }
>>
>> Modified: lld/trunk/ELF/LTO.h
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/LTO.h?rev=296702&r1=296701&r2=296702&view=diff
>>
>> ==============================================================================
>> --- lld/trunk/ELF/LTO.h (original)
>> +++ lld/trunk/ELF/LTO.h Wed Mar  1 17:00:10 2017
>> @@ -49,6 +49,7 @@ public:
>>  private:
>>    std::unique_ptr<llvm::lto::LTO> LTOObj;
>>    std::vector<SmallString<0>> Buff;
>> +  std::vector<std::unique_ptr<MemoryBuffer>> Files;
>>  };
>>  }
>>  }
>>
>> Modified: lld/trunk/ELF/Options.td
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Options.td?rev=296702&r1=296701&r2=296702&view=diff
>>
>> ==============================================================================
>> --- lld/trunk/ELF/Options.td (original)
>> +++ lld/trunk/ELF/Options.td Wed Mar  1 17:00:10 2017
>> @@ -392,4 +392,6 @@ def opt_remarks_filename: S<"opt-remarks
>>  def opt_remarks_with_hotness: F<"opt-remarks-with-hotness">,
>>    HelpText<"Include hotness informations in the optimization remarks
>> file">;
>>  def save_temps: F<"save-temps">;
>> +def thinlto_cache_dir: J<"thinlto-cache-dir=">,
>> +  HelpText<"Path to ThinLTO cached object file directory">;
>>  def thinlto_jobs: J<"thinlto-jobs=">, HelpText<"Number of ThinLTO jobs">;
>>
>> Added: lld/trunk/test/ELF/lto/Inputs/cache.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/Inputs/cache.ll?rev=296702&view=auto
>>
>> ==============================================================================
>> --- lld/trunk/test/ELF/lto/Inputs/cache.ll (added)
>> +++ lld/trunk/test/ELF/lto/Inputs/cache.ll Wed Mar  1 17:00:10 2017
>> @@ -0,0 +1,10 @@
>> +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
>> +target triple = "x86_64-unknown-linux-gnu"
>> +
>> +define i32 @main() {
>> +entry:
>> +  call void (...) @globalfunc()
>> +  ret i32 0
>> +}
>> +
>> +declare void @globalfunc(...)
>>
>> Added: lld/trunk/test/ELF/lto/cache.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/test/ELF/lto/cache.ll?rev=296702&view=auto
>>
>> ==============================================================================
>> --- lld/trunk/test/ELF/lto/cache.ll (added)
>> +++ lld/trunk/test/ELF/lto/cache.ll Wed Mar  1 17:00:10 2017
>> @@ -0,0 +1,15 @@
>> +; RUN: opt -module-hash -module-summary %s -o %t.o
>> +; RUN: opt -module-hash -module-summary %p/Inputs/cache.ll -o %t2.o
>> +
>> +; RUN: rm -Rf %t.cache && mkdir %t.cache
>> +; RUN: ld.lld --thinlto-cache-dir=%t.cache -o %t3.o %t2.o %t.o
>> +
>> +; RUN: ls %t.cache | count 2
>> +
>> +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
>> +target triple = "x86_64-unknown-linux-gnu"
>> +
>> +define void @globalfunc() #0 {
>> +entry:
>> +  ret void
>> +}
>>
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-commits
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20181015/974387d7/attachment.html>


More information about the llvm-commits mailing list